Vapotherm (VAPO) 10-K 24 Feb 22 2021 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Feb. 18, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Entity Registrant Name	Vapotherm, Inc
Entity Central Index Key	0001253176
Entity Tax Identification Number	46-2259298
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 543.1
Entity File Number	001-38740
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	100 Domain Drive
Entity Address, City or Town	Exeter
Entity Address, State or Province	NH
Entity Address, Postal Zip Code	03833
City Area Code	603
Local Phone Number	658-0011
Entity Common Stock, Shares Outstanding		26,184,632
ICFR Auditor Attestation Flag	true
Title of 12(b) Security	Common Stock, $0.001 per value per share
Trading Symbol	VAPO
Security Exchange Name	NYSE
Auditor Firm ID	248
Auditor Name	GRANT THORNTON LLP
Auditor Location	New York, New York
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Portions of the registrant’s Definitive Proxy Statement relating to the Annual Meeting of Stockholders, scheduled to occur on June 21, 2022, are incorporated by reference into Part III of this report.

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 57,071	$ 113,683
Accounts receivable, net	10,909	23,488
Inventories	36,562	19,873
Prepaid expenses and other current assets	5,205	5,041
Total current assets	109,747	162,085
Property and equipment, net	22,157	20,573
Operating lease right-of-use assets	7,045	8,260
Restricted cash	253	1,853
Goodwill	15,300	16,226
Intangible assets, net	4,398	5,694
Deferred income tax assets	78
Other long-term assets	1,107	967
Total assets	160,085	215,658
Current liabilities
Accounts payable	5,923	4,967
Contract liabilities	2,081	2,977
Accrued expenses and other current liabilities	28,559	34,033
Revolving loan facility	6,608
Total current liabilities	43,171	41,977
Long-term loans payable, net	39,726	39,653
Revolving loan facility		4,888
Deferred income tax liabilities		6
Other long-term liabilities	10,521	15,229
Total liabilities	93,418	101,753
Commitments and contingencies (Note 11)
Stockholders' equity
Preferred stock ($0.001 par value) 25,000,000 shares authorized; no shares issued and outstanding as of December 31, 2021 and 2020
Common stock ($0.001 par value) 175,000,000 shares authorized as of December 31, 2021 and 2020; 26,126,253 and 25,722,984 shares issued and outstanding as of December 31, 2021 and 2020, respectively	26	26
Additional paid-in capital	443,358	430,781
Accumulated other comprehensive income	26	41
Accumulated deficit	(376,743)	(316,943)
Total stockholders' equity	66,667	113,905
Total liabilities and stockholders’ equity	$ 160,085	$ 215,658

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	25,000,000	25,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	175,000,000	175,000,000
Common stock, shares issued	26,126,253	25,722,984
Common stock, shares outstanding	26,126,253	25,722,984

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Net revenue	$ 113,292,000	$ 125,733,000	$ 48,104,000
Cost of revenue	60,104,000	62,687,000	26,793,000
Gross profit	53,188,000	63,046,000	21,311,000
Operating expenses
Research and development	18,410,000	16,956,000	13,376,000
Sales and marketing	60,140,000	65,065,000	37,689,000
General and administrative	31,375,000	24,039,000	18,410,000
Intangible asset impairment	323,000	0	0
Loss on disposal of property and equipment	105,000
Total operating expenses	110,353,000	106,060,000	69,475,000
Loss from operations	(57,165,000)	(43,014,000)	(48,164,000)
Other (expense) income
Interest expense	(2,595,000)	(4,711,000)	(5,096,000)
Foreign currency gain (loss)	(225,000)	114,000	44,000
Interest income	91,000	257,000	860,000
Other income	18,000
Gain on litigation settlement		15,000	1,151,000
Loss on extinguishment of debt		(4,163,000)
Net loss before income taxes	(59,876,000)	(51,502,000)	(51,205,000)
Benefit for income taxes	(76,000)	0	(146,000)
Net loss	(59,800,000)	(51,502,000)	(51,059,000)
Other comprehensive income (loss)
Foreign currency translation adjustments	(15,000)	(3,000)	44,000
Total other comprehensive income (loss)	(15,000)	(3,000)	44,000
Total comprehensive loss	$ (59,815,000)	$ (51,505,000)	$ (51,015,000)
Net loss per share - basic and diluted	$ (2.31)	$ (2.16)	$ (2.74)
Weighted-average number of shares used in calculating net loss per share, basic and diluted	25,936,970	23,818,447	18,604,707

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	At-The-Market offering	Common Stock	Common StockAt-The-Market offering	Additional Paid-in Capital	Additional Paid-in CapitalAt-The-Market offering	Accumulated Other Comprehensive Income	Accumulated Deficit
Beginning balance at Dec. 31, 2018	$ 51,561		$ 17		$ 265,926			$ (214,382)
Beginning balance, shares at Dec. 31, 2018			16,782,837
Issuance of common stock, net	48,276		$ 4		48,272
Issuance of common stock, net, shares			3,570,750
Issuance of common stock warrants	293				293
Issuance of common stock upon repayment of nonrecourse loans	144				144
Issuance of common stock upon repayment of non-recourse loan, Shares			79,854
Issuance of common stock upon exercise of warrants, shares			12,164
Issuance of common stock upon exercise of options	242				242
Issuance of common stock upon exercise of options, shares			150,176
Issuance of common stock in connection with restricted stock awards	137				137
Issuance of common stock in connection with restricted stock awards, shares			238,106
Issuance of common stock for services, shares			17,644
Issuance of common stock for services	265				265
Stock-based compensation expense	3,836				3,836
Foreign currency translation adjustments	44						$ 44
Net loss	(51,059)							(51,059)
Ending balance at Dec. 31, 2019	53,739		$ 21		319,115		44	(265,441)
Ending balance, shares at Dec. 31, 2019			20,851,531
Issuance of common stock, net	93,827	$ 9,784	$ 4	$ 1	93,823	$ 9,783
Issuance of common stock, net, shares			3,852,500	511,648
Issuance of common stock upon exercise of warrants, shares			79,442
Issuance of common stock upon exercise of options	593				593
Issuance of common stock upon exercise of options, shares			223,998
Issuance of common stock under the Employee Stock Purchase Plan	824				824
Issuance of common stock under the Employee Stock Purchase Plan, shares			58,140
Issuance of common stock in connection with restricted stock units and awards	213				213
Issuance of common stock in connection with restricted stock units and awards, shares			126,338
Issuance of common stock for services, shares			19,387
Issuance of common stock for services	441				441
Stock-based compensation expense	5,989				5,989
Foreign currency translation adjustments	(3)						(3)
Net loss	(51,502)							(51,502)
Ending balance at Dec. 31, 2020	113,905		$ 26		430,781		41	(316,943)
Ending balance, shares at Dec. 31, 2020			25,722,984
Issuance of common stock upon exercise of options	$ 1,511				1,511
Issuance of common stock upon exercise of options, shares	168,289		168,289
Issuance of common stock under the Employee Stock Purchase Plan	$ 1,139				1,139
Issuance of common stock under the Employee Stock Purchase Plan, shares			75,313
Issuance of common stock in connection with restricted stock units and awards	161				161
Issuance of common stock in connection with restricted stock units and awards, shares			141,569
Issuance of common stock for services, shares			18,098
Issuance of common stock for services	413				413
Stock-based compensation expense	9,353				9,353
Foreign currency translation adjustments	(15)						(15)
Net loss	(59,800)							(59,800)
Ending balance at Dec. 31, 2021	$ 66,667		$ 26		$ 443,358		$ 26	$ (376,743)
Ending balance, shares at Dec. 31, 2021			26,126,253

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities
Net loss	$ (59,800,000)	$ (51,502,000)	$ (51,059,000)
Adjustments to reconcile net loss to net cash used in operating activities
Stock-based compensation expense	9,766,000	6,430,000	3,836,000
Depreciation and amortization	5,648,000	4,769,000	3,078,000
Loss on extinguishment of debt		4,163,000
Non-cash lease expense	1,764,000	1,140,000
Intangible asset impairment	323,000	0	0
Loss on disposal of property and equipment	260,000	250,000	101,000
Amortization of discount on debt	128,000	222,000	234,000
Change in fair value of contingent consideration	(1,813,000)
Provision for bad debts	(161,000)	72,000	104,000
Deferred income taxes	(76,000)	70,000	(147,000)
Provision for inventory valuation	70,000	(534,000)	(543,000)
Gain on litigation settlement		(15,000)	(1,151,000)
Changes in operating assets and liabilities:
Accounts receivable	12,400,000	(14,810,000)	(833,000)
Inventories	(16,759,000)	(10,157,000)	5,606,000
Prepaid expenses and other assets	1,458,000	(483,000)	(1,218,000)
Accounts payable	798,000	1,461,000	720,000
Contract liabilities	(892,000)	2,494,000	150,000
Accrued expenses and other current liabilities	(6,724,000)	18,101,000	1,460,000
Operating lease liabilities, current and long-term	(1,761,000)	(1,154,000)
Net cash used in operating activities	(55,371,000)	(39,468,000)	(39,662,000)
Cash flows from investing activities
Purchases of property and equipment	(5,895,000)	(9,797,000)	(4,747,000)
Acquisition of business, net of cash acquired	(1,304,000)	(8,372,000)	(1,560,000)
Net cash used in investing activities	(7,199,000)	(18,169,000)	(6,307,000)
Cash flows from financing activities
Proceeds from issuance of common stock in connection with public offering, net		94,155,000	48,669,000
Proceeds from exercise of stock options and purchase of restricted stock awards	1,511,000	593,000	386,000
Common stock offering costs		(471,000)	(393,000)
Proceeds from loans		40,000,000	10,500,000
Repayment of loans		(42,500,000)
Payments of debt extinguishment costs		(3,765,000)
Debt issuance costs		(475,000)	(29,000)
Proceeds from short-term line of credit and revolving loan facility	4,882,000	5,883,000	7,500,000
Repayments on short-term line of credit and revolving loan facility	(3,162,000)	(4,495,000)	(7,184,000)
Net cash provided by financing activities	4,370,000	99,676,000	59,449,000
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(12,000)	(10,000)	5,000
Net increase in cash, cash equivalents, and restricted cash	(58,212,000)	42,029,000	13,485,000
Cash, cash equivalents and restricted cash
Beginning of year	115,536,000	73,507,000	60,022,000
End of year	57,324,000	115,536,000	73,507,000
Supplemental disclosures of cash flow information
Interest paid during the period	2,466,000	4,439,000	4,793,000
Property and equipment purchases in accrued expenses	422,000	145,000	135,000
Issuance of common stock upon vesting of restricted stock units and awards	161,000	213,000	402,000
Issuance of warrants in conjunction with debt draw down			$ 293,000
At-The-Market offering
Cash flows from financing activities
Proceeds from issuance of common stock in connection with public offering, net		9,927,000
Employee Stock Purchase Plan
Cash flows from financing activities
Proceeds from issuance of common stock under Employee Stock Purchase Plan	$ 1,139,000	$ 824,000

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business	1. Description of Business Vapotherm, Inc. (the “Company”) was founded in 1993 and reincorporated under the laws of the State of Delaware in 2013. The Company is a global medical technology company primarily focused on the care of patients of all ages suffering from the respiratory distress often associated with complex lung diseases such as chronic obstructive pulmonary disease (“COPD”), congestive heart failure (“CHF”), pneumonia, asthma and COVID-19. The Company’s device solutions are focused on High Velocity Nasal Insufflation (“HVNI”, or “High Velocity Therapy”), which delivers non-invasive ventilatory support to patients by providing heated, humidified, oxygenated air at high velocities through a small-bore nasal interface, and on closed loop control systems such as our Oxygen Assist Module, designed to automatically maintain SPO2 levels within a specified range for a defined period of time. The Company’s digital solutions are focused on at home patient monitoring, using proprietary algorithms to predict impending respiratory episodes before they occur and coordinate timely intervention, obviating the need for costly hospital admissions and minimizing patient distress. The Company’s clinical solutions include affiliations with leading pulmonologists and other clinicians, offering both in person and virtual care, as well as its own call center staffed by experienced nurses. While these device, digital and clinical solutions function independently, the Company believes leveraging the three together can create a unique healthcare ecosystem, focused on delivering high quality, efficient respiratory care. High Velocity Therapy is an advanced form of high flow therapy that is differentiated due to its ability to deliver breathing gases, including oxygen, at a high velocity, for the treatment of spontaneously breathing patients with either Type 1 hypoxic respiratory distress, like that experienced by patients with pneumonia or COVID-19, or Type 2 hypercapnic respiratory distress, like that experienced by patients with COPD. The Company’s Precision Flow systems, which use High Velocity Therapy technology, are clinically validated alternatives to, and address many limitations of, the current standard of care for the treatment of respiratory distress in a hospital setting. The Company’s next generation High Velocity Therapy system, known as HVT 2.0, received 510k clearance from the FDA in 2021 and is currently in limited market release. The HVT 2.0 platform is approved for therapy in multiple settings of care, including the home. In certain countries outside the United States, the Company currently offers its Oxygen Assist Module, or OAM, which launched in the United Kingdom, select European markets, and Israel in late 2020. The Oxygen Assist Module can be used with most versions of the Company’s Precision Flow system as well as the HVT 2.0. The Oxygen Assist Module helps clinicians maintain a patient’s pulse oxygen saturation, or SpO2, within a target SpO2 range over a greater period of time while requiring significantly fewer manual adjustments to the equipment. Maintenance of the prescribed oxygen saturation range may reduce the health risks associated with dosing too much, or too little, oxygen, particularly in neonates. In neonates, these risks include visual or developmental impairment or death. The Company sells its Precision Flow systems to hospitals through a direct sales organization in the United States, the United Kingdom and Germany and through distributors in other select countries outside of those countries. The Oxygen Assist Module is sold through a direct sales organization in the United Kingdom and Germany and through distributors in Europe and the Middle East. The Company is in the process of seeking FDA approval to market the Oxygen Assist Module in the United States. In addition, the Company employs field-based clinical educators who focus on medical education and training in the effective use of its products and help facilitate increased adoption and utilization. The Company focuses on physicians, respiratory therapists and nurses who work in acute hospital settings, including the ED and adult, pediatric and neonatal ICUs. The Company’s relationship with these clinicians is particularly important, as it enables the Company’s products to follow patients through the care continuum. In August 2019, the Company completed a public offering of 3,570,750 shares of common stock, which included the full exercise by the underwriters of their option to purchase 465,750 shares of common stock, at a price of $14.50 per share, which raised net proceeds of $48.3 million after deducting the underwriting discount of $3.1 million and offering expenses of $0.4 million. On December 20, 2019, the Company entered into an Open Market Sales Agreement (the “ATM Agreement”) with Jefferies LLC (“Jefferies”), under which the Company may offer and sell its common stock having aggregate sales proceeds of up to $50.0 million from time to time through Jefferies as its sales agents. In May 2020, the Company completed a public offering of 3,852,500 shares of common stock, which included the full exercise by the underwriters of their option to purchase 502,500 shares of common stock, at a price of $26.00 per share, which raised net proceeds of $93.8 million after deducting the underwriting discount of $6.0 million and offering expenses of $0.3 million. On November 13, 2020, the Company acquired HGE Health Care Solutions LLC (“HGE”) See Note 3 “Business Combinations” to these consolidated financial statements for details of this transaction. On November 2, 2021, HGE acquired PCI Management Group LLC (“PCI”) and became affiliated with a physician practice managed by PCI, Pulmonary Care Innovations, PLLC (“RespirCare”), which the Company consolidates for accounting and tax purposes. See Note 3 “Business Combinations” to these consolidated financial statements for details of this transaction.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Significant Accounting Policies	2. Significant Accounting Policies Basis of Presentation The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Principles of Consolidation These consolidated financial statements include the financial statements of Solus Medical Ltd. (“Solus”), a wholly owned subsidiary of the Company based in the United Kingdom, HGE, a wholly owned subsidiary of the Company located in the United States, Vapotherm Deutschland GmbH, a wholly owned subsidiary of the Company located in Germany, and PCI and RespirCare, which were acquired by HGE in the fourth quarter of 2021. All intercompany accounts and transactions have been eliminated upon consolidation. Segment Information Operating segments are defined as components of an enterprise for which separate discrete financial information is available and evaluated regularly by the chief operating decision maker in deciding how to allocate resources and in assessing performance. The Company globally manages the business within one reporting segment, Vapotherm, Inc. and three reporting units, Vapotherm, Solus and HGE. Segment information is consistent with how management reviews the business, makes investing and resource allocation decisions and assesses operating performance. The majority of the Company’s long-term assets are located in the United States. Long-term assets located outside the United States total $2.4 million and $0.2 million at December 31, 2021 and 2020, respectively. Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires the Company to make judgments, assumptions, and estimates that affect the reported amounts of assets, liabilities, revenue and expenses, and the related disclosure of contingent assets and liabilities. The Company evaluates its estimates on an ongoing basis. The Company bases its estimates on historical experience and various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Significant estimates relied upon in preparing these consolidated financial statements include calculation of stock-based compensation, fair values of acquired assets and liabilities, including goodwill and intangibles assets, realizability of inventories, allowance for bad debts, accrued expenses, including the fair value of contingent consideration, the valuation allowances against deferred income tax assets, and assessments of impairment with respect to long-lived and intangible assets. Actual results may differ from these estimates. Reclassification Certain amounts in 2020 and 2019 have been reclassified to conform to the presentation in 2021. None of the reclassifications had any impact to the Company’s results of operations. Financial Instruments and Concentrations of Credit Risk As of December 31, 2021 and 2020, the Company’s financial instruments were comprised of cash and cash equivalents, restricted cash, accounts receivable, accounts payable and debt, the carrying amounts of which approximated fair value due to the short-term nature or market interest rates. All of the Company’s cash and cash equivalents are maintained at creditworthy financial institutions. At December 31, 2021 and 2020, deposits exceed the amount of any insurance provided. The Company extends credit to customers in the normal course of business but typically does not require collateral or any other security to support amounts due. Management performs ongoing credit evaluations of its customers. An allowance for potentially uncollectible accounts is provided based on history, economic conditions, and composition of the accounts receivable aging. In some cases, the Company makes allowances for specific customers based on these and other factors. Provisions for the allowance for doubtful accounts are recorded in general and administrative expenses in the accompanying consolidated statements of comprehensive loss. Supplier Risk The Company obtains some of the components and subassemblies included in its Precision Flow systems and obtains its Oxygen Assist Module from single source suppliers and the partial or complete loss of one or more of these suppliers could cause significant production delays, an inability to meet customer demand and a substantial loss in revenue. Foreign Currency and Foreign Operations The functional currency of the Company is the currency of the primary economic environment in which the entity operates, which is the U.S. dollar. For the Company’s non-U.S. subsidiaries that transacts in a functional currency other than the U.S. dollar, assets and liabilities are translated at current rates of exchange at the balance sheet date. Income and expense items are translated at the average foreign currency exchange rates for the period. Adjustments resulting from the translation of the financial statements of its foreign operations into U.S. dollars are excluded from the determination of net loss and are recorded in accumulated other comprehensive income (loss), a separate component of stockholders’ equity. Realized foreign currency gains or losses arising from transactions denominated in foreign currencies are recorded in other (expense) income in the consolidated statements of comprehensive loss. Cash, Cash Equivalents, and Restricted Cash The Company considers all highly liquid temporary investments purchased with original maturities of 90 days or less to be cash equivalents. The Company holds restricted cash related to certificates of deposits and collateral in relation to lease agreements. As of December 31, 2021, $1.1 million of the Company’s $57.3 million of cash, cash equivalents and restricted cash balance was located outside the United States. The following table presents the components of total cash, cash equivalents, and restricted cash as set forth in the Company’s consolidated statements of cash flows: December 31, 2021 2020 Cash and cash equivalents $ 57,071 $ 113,683 Restricted cash 253 1,853 Total cash, cash equivalents, and restricted cash $ 57,324 $ 115,536 Inventories Inventories consist of finished goods and component parts and are valued at the lower of cost or net realizable value, determined by the first-in, first-out (“FIFO”) method. On a quarterly basis, the Company evaluates the carrying costs of both finished goods and component part items. To the extent that such costs exceed future demand estimates, exhibit historical turnover at rates less than current inventory levels, or exceed estimated selling prices less costs to sell, the Company reduces the carrying value of inventories to its net realizable value. The Company only capitalizes pre-launch inventories when purchased for commercial sale and it deems regulatory approval to be probable. Public Offering Costs The Company incurs public offering costs consisting of legal, accounting and other costs directly attributable to the Company’s public offerings and defers such costs until the closing of the offerings. Upon closing of offerings, such costs are netted against the proceeds received. As of December 31, 2021 and 2020, no amounts were deferred. Property and Equipment Property and equipment are recorded at cost. Depreciation is recognized over the estimated useful lives of the related assets on a straight-line basis, except for tooling for which depreciation is recognized utilizing the units-of-production method prospectively beginning on January 1, 2021. The Company changed to the units-of-production method to be tter reflect the pattern of economic consumption of the tooling. When impairment indicators are present, the Company evaluates the recoverability of its long-lived assets. If the assessment indicates an impairment, the affected assets are written down to fair value. There were no impairments of property and equipment during 2021, 2020, or 2019. Repairs and maintenance are expensed as incurred. Expenditures that increase the value or productive capacity of assets are capitalized. When property and equipment are retired, sold, or otherwise disposed of, the asset’s carrying amount and related accumulated depreciation are removed from the accounts and any gain or loss is included in operating expenses. The lives used in computing straight-line depreciation are as follows: Number of Years Equipment 3 - 7 Furniture 5 - 7 Manufacturing equipment 3 - 10 Software 2 - 3 Demonstration, placements and evaluation units 3 - 7 Leasehold improvements Lesser of life of lease or 10 years Intangible Assets Intangible assets are related to customer relationships, developed technology, customer agreements, trademarks and trade names and are amortized on a straight-line basis over their useful lives. Amortization is recorded within sales and marketing expenses in the consolidated statements of comprehensive loss for customer-related intangible assets while amortization of other intangible assets is included within general and administrative expenses in the consolidated statements of comprehensive loss. Intangible assets are evaluated for impairment whenever events or circumstances indicate an asset may be impaired. During the fourth quarter of 2021, the Company recorded an impairment charge of $0.3 million related to trade names and trademarks no longer in use. There were no impairments of intangible assets during 2020 or 2019. Goodwill Goodwill represents the difference between the purchase price and the fair value of the identifiable tangible and intangible net assets when accounted for using the purchase method of accounting in a business combination. Goodwill is not amortized but reviewed for impairment. Goodwill is reviewed annually, as of October 1, and whenever events or changes in circumstances indicate that the carrying value of the goodwill may not be recoverable. The Company compares the fair value of its reporting units to their carrying values. If the carrying value of the net assets assigned to a reporting unit exceeds the fair value of the reporting unit, the Company would record an impairment loss equal to the difference. There was no impairment of goodwill during 2021, 2020 or 2019. Leases The Company’s operating leases primarily consist of real estate leases for office, manufacturing, research and development, and warehouse space, as well as certain vehicle and equipment leases. Prior to adopting ASU 2016-02, Leases (Topic 842) ASC 842 requires lessees to recognize leases on the balance sheet as a lease liability with a corresponding right-of-use asset, subject to certain permitted accounting policy elections. Under ASC 842, the Company determines whether a contract is or contains a lease at the inception of the contract. This determination is based on whether the contract provides the Company the right to control the use of a physically distinct asset and substantially all of the capacity of an asset. Leases with an initial noncancelable term of twelve months or less that do not include an option to purchase the underlying asset that the Company is reasonably certain to exercise are classified as short-term leases. The Company has elected as an accounting policy to exclude from the consolidated balance sheets the right-of-use assets and lease liabilities related to short-term leases. The Company recognizes rent expense for its operating leases on a straight-line basis over the term of the lease. Certain of the Company’s leases include options to extend or terminate the lease at its sole discretion. The Company does not consider in the measurement of right-of-use assets and lease liabilities an option to extend or terminate a lease if the Company is not reasonably certain to exercise the option. As of December 31, 2021, the Company has not included any options to extend its leases in its measurement of the related right-of-use assets or lease liabilities as the Company is not reasonably certain it will exercise the options. Certain of the Company’s leases include covenants that oblige the Company, at its sole expense, to repair and maintain the leased asset periodically during the lease term. The Company is not a party to any leases that contain residual value guarantees. Many of the Company’s leases include fixed and variable payments. Among other charges, variable payments related to real estate leases include real estate taxes, insurance, operating expenses, and common area maintenance, which are usually billed at actual amounts incurred proportionate to the Company’ rented square feet of the building. Variable payments related to vehicle and equipment leases relate to usage of the underlying asset, sales and use tax, and value-added tax. Variable payments that do not depend on an index or rate are expensed as incurred and are not included in the measurement of the lease liability. In accordance with the guidance in ASC 842, components of a lease should be split into three categories: lease components (e.g. buildings, vehicles, etc.), non-lease components (e.g. common area maintenance, consumables, etc.), and non-components (e.g. property taxes, insurance, etc.). The fixed and in-substance fixed contract consideration (including any related to non-components) must be allocated to the lease components and non-lease components based on their relative fair values. The Company elected the accounting policy to not separate lease and non-lease components for its real estate, vehicle, and equipment leases. Therefore, each lease component and the related non-lease components and non-components are accounted for together as a single component. The Company measures its lease liability for each leased asset as the present value of lease payments, as defined in ASC 842, discounted using a discount rate specific to the terms of the underlying lease. The Company’s right-of-use assets are equal to the related lease liabilities, adjusted for lease incentives received including tenant improvement allowances, initial direct costs incurred related to the lease, and payments made to the lessor prior to the lease commencement date. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company estimates its incremental borrowing rate for each leased asset based on the interest rate the Company would incur to borrow an amount equal to the lease payments on a collateralized basis over a similar term in a similar economic environment. Contingent Consideration Contingent consideration is initially recorded at its acquisition date fair value, is remeasured at each reporting date and is included in accrued expenses and other current liabilities and other long-term liabilities in the Company’s consolidated balance sheets. Fair value is estimated utilizing several key assumptions and is remeasured at each reporting period with changes in fair value being recorded as a component of general and administrative expense in the consolidated statements of comprehensive loss . See Note 3 “Business Combinations” for a rollforward of contingent consideration and Note 9 “Accrued Expenses and Other Current Liabilities and Other Long-Term Liabilities” for balances at December 31, 2021 and 2020. Product Warranty The Company provides its customers with a standard one-year Balance at December 31, 2019 $ 225 Provisions for warranty obligations 636 Settlements (300 ) Balance at December 31, 2020 561 Provisions for warranty obligations 205 Settlements (436 ) Balance at December 31, 2021 $ 330 Deferred Financing Costs Direct financing costs are deferred and amortized as a component of interest expense, over the term of the related debt. The long-term portion of the balance of unamortized deferred financing costs related to Company’s term loan is presented as a reduction of the related borrowing arrangement liability and totals $0.3 million at each of December 31, 2021 and 2020. The unamortized deferred financing costs related to the Company’s revolving facility are recorded in prepaid expenses and other current assets in the Company’s consolidated balance sheet and totals less than $0.1 million at December 31, 2020. There were no unamortized deferred financing costs recorded in prepaid and other current assets at December 31, 2021. Insurance Effective January 1, 2020, the Company became self-insured for certain obligations related to health insurance. The Company also purchases stop-loss insurance to protect itself from material losses. Judgments and estimates are used in determining the potential value associated with reported claims and for events that have occurred but have not been reported. The Company’s estimates consider expected claim experience and other factors. Receivables for insurance recoveries are recorded as assets, on an undiscounted basis. The Company’s liabilities are based on estimates, and, while the Company believes that its accruals are adequate, the ultimate liability may be significantly different from the amounts recorded. Changes in claims experience, the Company’s ability to settle claims or other estimates and judgments used by management could have a material impact on the amount and timing of expense for any period. Revenue Recognition The Company’s revenue is primarily derived from the sale of products, leases and services. Product revenue consists of capital equipment and single-use disposables that are shipped and billed to customers both domestically and internationally. The Company’s main capital equipment products are the Precision Flow systems, the Vapotherm Transfer Unit 2.0 and Q50 compressor. The Company’s main disposable products are single-use disposables and nasal interfaces, or cannulas, and adaptors. Lease revenue consists of two components which include capital equipment that the Company leases to its customers and, in certain situations, an allocation from disposable revenue to other lease revenue upon the sale of disposable products in bundled arrangements involving the placement of Precision Flow capital units for use by the customer at no upfront charge in connection with the customer’s ongoing purchase of disposable products. Service revenue consists of fees associated with routine service of capital units and the sale of extended service contracts and preventative maintenance plans, which a re purchased by a small portion of the Company’s customer base. In addition, the Company sells small quantities of component parts in the United States, United Kingdom and to third-party international service centers who provide service on Precision Flow capital units outside of the United States and United Kingdom . Service revenue also includes fees from remote patient monitoring services sold through Vapotherm Access. Freight revenue is based upon actual freight costs plus a percentage markup of such costs associated with the shipment of products domestically, and to a lesser extent, internationally, and is included in service revenue. Rebates and fees consist of contractually obligated administrative fees and percentage-of-sales rebates paid to Group Purchasing Organizations (“GPOs”), Integrated Delivery Networks (“IDNs”) and distributor partners and accounted for as a reduction of revenue. Under the Financial Accounting Standard Board’s (“FASB”) Accounting Standards Codifications (“ASC”) 606, Revenue from Contracts with Customers (“ASC 606”), revenue is recognized when a customer obtains control of promised goods or services, in an amount that reflects the consideration which the Company expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of ASC 606, the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract and assesses whether each promised good or service is distinct and determines those that are performance obligations. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. Sales, value-added, and other taxes collected on behalf of third parties are excluded from revenue. The Company’s standard payment terms are generally 30 days from the date of sale. Contracts with customers may contain multiple performance obligations. For such arrangements, the transaction price is allocated to each performance obligation based on the estimated relative stand-alone selling prices of the promised products or services underlying each performance obligation. The Company determines stand-alone selling prices based on the price at which the performance obligation is sold separately. If the stand-alone selling price is not observable through past transactions, the Company estimates the stand-alone selling price taking into account available information such as market conditions and internally approved pricing guidelines related to the performance obligations. Revenue is generally recognized when the customer obtains control of the Company’s product, which generally occurs at a point in time upon shipment based on the contractual shipping terms of a contract. Product and service revenue is measured as the amount of consideration the Company expects to receive in exchange for transferring products or services to a customer. To the extent the transaction price includes variable consideration, the Company estimates the amount of variable consideration that should be included in the transaction price utilizing the expected value amount method to which the Company expects to be entitled. As such, revenue on sales is recorded net of prompt pay discounts and payments made to GPOs, IDNs and distributors. Variable consideration is included in the transaction price if, in the Company’s judgment, it is probable that a significant future reversal of cumulative revenue under the contract will not occur. Determination of whether to include estimated amounts in the transaction price is based largely on an assessment of the Company’s anticipated performance and all information (historical, current and forecasted) that is reasonably available. The Company believes that the estimates it has established are reasonable based upon current facts and circumstances. Applying different judgments to the same facts and circumstances could result in different estimates. When determining the transaction price of a contract, an adjustment is made if payment from a customer occurs either significantly before or significantly after performance, resulting in a significant financing component. Applying a practical expedient under ASC 606, the Company does not assess whether a significant financing component exists if the period between when the Company performs its obligations under the contract and when the customer pays is one year or less. None of the Company’s contracts contained a significant financing component during the years ended December 31, 2021, 2020 or 2019. The Company’s contracts with its customers have a duration of less than one year. Therefore, the Company has elected to apply a practical expedient and recognizes the incremental costs of obtaining contracts as an expense. These costs are included in sales and marketing expense in the accompanying consolidated statements of comprehensive loss. Lease Revenue The Company also enters into agreements to lease its capital equipment. For such sales, the Company accounts for revenue under ASC 842 and assesses and classifies these transactions as sales-type or operating leases based on whether the lease transfers ownership of the equipment to the lessee by the end of the lease term. This criterion is met in situations in which the lease agreement provides for the transfer of title at or shortly after the end of the lease term. Equipment included in arrangements including transfer of title are accounted for as sales-type leases and the Company recognizes the present value of the lease payments due over the lease term as revenue at the inception of the lease. The Company records the present value of future lease payments in prepaid expenses and other current assets in the accompanying consolidated balance sheets ; these amounts totaled $ million and $ 2.7 million at December 31, 20 2 1 and 20 20 , respectively . Equipment included in arrangements that do not include the transfer of title, nor any of the sales-type or direct financing lease criteria, are accounted for as operating leases and revenue is recognized on a straight-line basis over the term of the lease. Prior to the adoption of ASC 842 effective January 1, 2020, the Company accounted for such transactions under ASC 840 and there was no change in the Company’s accounting for such transactions upon the adoption of ASC 842. The Company also enters into agreements involving the placement of Precision Flow capital units for use by the customer at no upfront charge in connection with the customer’s ongoing purchase of disposable products. In these bundled arrangements, revenue recognized for the sale of the disposables is allocated between disposable revenue and other lease revenue based on the estimated relative stand-alone selling prices of the individual performance obligations. Shipping and Handling Costs Amounts billed to customers for shipping and handling are included in service revenue. Shipping and handling costs are included in costs of sales. The total costs of shipping and handling for the years ended December 31, 2021, 2020 and 2019 totaled $1.6 million, $2.5 million and $1.0 million, respectively. Sales and Value-Added Taxes When required by local jurisdictions, the Company bills its customers for sales tax and value-added tax calculated on each sales invoice and records a liability for the sales and value-added tax payable, which is included in accrued expenses and other current liabilities in the consolidated balance sheets. Sales tax and value-added tax billed to a customer are not included in the Company’s revenue. Research and Development Costs Research and development costs are expensed when incurred and are related primarily to product design, prototype development and testing, the investigation of possible follow-on product enhancements and new product releases, and investigation of complementary technologies potentially available to enhance the Company’s offerings in the marketplace. Stock-Based Compensation The Company maintains an equity incentive plan to provide long-term incentives for employees, consultants, and members of the board of directors. The plan allows for the issuance of non-statutory and incentive stock options, restricted stock, unrestricted stock, stock units, including restricted stock units, and stock appreciation rights to employees, consultants and non-employee directors. The Company recognizes stock-based compensation expense for awards of equity instruments to employees and non-employees based on the grant date fair value of those awards in accordance with ASC Topic 718, Stock Compensation (“ASC 718”). ASC 718 requires all equity-based compensation awards, including grants of restricted shares and stock options, to be recognized as expense in the consolidated statements of comprehensive loss based on their grant date fair values. The fair value of each option grant is estimated on the grant date using the Black-Scholes option pricing model. The fair value of restricted stock and restricted stock units is measured at the market value of the related shares of the Company’s common stock on the grant date. The Company recognizes stock-based expense for shares of its common stock issued pursuant to the Vapotherm, Inc. 2018 Employee Stock Purchase Plan (“ESPP”) on a straight-line basis over the related offering period. The Company estimates the fair value of shares to be issued under the ESPP based on a combination of options valued Scholes option pricing model. The expected life is determined based on the contractual term. Dividend yield , risk-free interest rate, forfeiture rates and expected volatility are estimated in a manner similar to option grants described abo ve. Net Income (Loss) per Share Basic net income (loss) per share is computed by dividing the net income (loss) by the weighted average number of common shares outstanding for the period. Diluted net income (loss) per share is computed by dividing the net income (loss) by the weighted average number of common shares outstanding for the period, including potential dilutive common shares. For purpose of this calculation, outstanding options, unvested restricted stock units, unissued employee stock purchase plan shares, and warrants are considered potential dilutive common shares. Income Tax The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the consolidated financial statements or in the Company’s tax returns. Deferred taxes are determined based on the difference between the financial reporting and tax basis of assets and liabilities using enacted tax rates in effect in the years in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies. The Company accounts for uncertainty in income taxes recognized in the consolidated financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the consolidated financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties. Recently Issued Accounting Pronouncements The Jumpstart Our Business Startups Act (the “JOBS Act”) allows an emerging growth company (“EGC”) to delay adoption of new or revised accounting pronouncements applicable to public companies until such pronouncements were made applicable to private companies. Since the Company was an EGC prior to December 31, 2020, the Company had elected to use the adoption dates applicable to private companies. As a result, the Company’s consolidated financial statements may not be comparable to the financial statements of issuers who are required to comply with the effective date for new or revised accounting standards that are applicable to public companies. Since the Company no longer qualified as an EGC as of December 31, 2020, subsequent to that date, it adopts future accounting pronouncements at dates applicable to public companies. Credit Losses (Topic 326): In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). This standard requires that credit losses be reported using an expected losses model rather than the incurred losses model that is

Business Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2021
Business Combinations [Abstract]
Business Combinations	3. Business Combinations PCI and RespirCare On November 2, 2021, HGE acquired PCI and became affiliated with a physician practice managed by PCI, RespirCare, which the Company consolidates for accounting and tax purposes. The principal assets acquired included goodwill and property and equipment. The Company undertook the acquisition in order to increase the number of patients for Vapotherm Access remote patient monitoring service. The purchase price, net of cash acquired, of $1.7 million was funded with cash payments of approximately $1.3 million and the settlement of $0.4 million of preexisting transactions. The acquisition has been accounted for as an acquisition of a business. The following table summarizes the preliminary purchase price allocation that includes the fair values of the separately identifiable assets acquired and liabilities assumed as of November 2, 2021: Cash $ 39 Accounts receivable 101 Prepaids and other current assets 11 Property and equipment 397 Operating lease right-of-use assets 316 Goodwill 1,302 Other long-term assets 9 Total assets acquired 2,175 Accounts payable (29 ) Other current liabilities (111 ) Other long-term liabilities (264 ) Total liabilities assumed (404 ) Total purchase price $ 1,771 The excess of purchase consideration over the fair value of net tangible assets acquired was recorded as goodwill. Goodwill associated with the acquisition was primarily attributable to the expansion opportunity of the Vapotherm Access remote monitoring platform and the value of the acquired workforce. The goodwill is deductible for tax purposes. The fair values assigned to tangible assets acquired and liabilities assumed are based on management’s estimates and assumptions. There were no intangible assets identified as part of the acquisition. The fair values of assets acquired and liabilities assumed may be subject to change as additional information is received. The Company expects to finalize the purchase price allocation as soon as practicable, but not later than one year from the acquisition date. The Company has included the financial results of PCI and RespirCare in the consolidated financial statements from the date of acquisition. Pro forma financial information has not been presented as the impact to the financial results is immaterial. Net revenue and net loss related of PCI and RespirCare since the date of acquisition were immaterial. The transaction costs associated with the acquisition were approximately $0.5 million and were recorded in general and administrative expense as incurred during 2021. HGE On November 13, 2020, the Company completed the acquisition of all outstanding membership interests of HGE, The Company finalized its valuation of the assets acquired and liabilities assumed during the three months ended March 31, 2021 and recorded an adjustment to correct immaterial errors related to the acquisition which reduced the preliminary purchase price by $2.3 million and decreased goodwill, intangible assets and other current liabilities by $2.2 million, $0.3 million and $0.3 million, respectively. The purchase price, net of cash acquired, of $19.3 million was funded with an initial cash payment of $8.4 million and $10.9 million of contingent consideration. The contingent consideration is payable in cash or common stock, at the sole discretion of the Company, and will be remitted in future milestone payments, one following calendar year 2021, one following calendar year 2022, and one following calendar year 2023. The final three payments will be adjusted up or down based on the revenue performance of certain HGE service offerings during those three years. The following table summarizes the final purchase price allocation that includes the fair values of the separately identifiable assets acquired and liabilities assumed as of November 13, 2020: Cash $ 2 Accounts receivable 518 Inventory 3 Prepaids and other current assets 238 Property and equipment 225 Operating lease right-of-use assets 2,329 Goodwill 13,398 Intangible assets 5,180 Other long-term assets 45 Total assets acquired 21,938 Accounts payable (32 ) Accrued expenses and other current liabilities (620 ) Contract liabilities (31 ) Other long-term liabilities (1,951 ) Total liabilities assumed (2,634 ) Total purchase price $ 19,304 The excess of purchase consideration over the fair value of net tangible and identifiable intangible assets acquired was recorded as goodwill. The fair values assigned to tangible and identifiable intangible assets acquired and liabilities assumed are based on management’s estimates and assumptions as of the date of acquisition. The fair value of the intangible asset associated with customer relationships was estimated using a discounted cash flow method with the application of the multi-period excess earnings method. Under this method, an intangible asset’s fair value is equal to the present value of the incremental after-tax cash flows attributable to only the subject intangible assets after deducting contributory asset charges. An income and expense forecast was built based upon specific intangible asset revenue and expense estimates. The fair value of the intangible asset associated with developed technology, trademarks and trade names were valued using the relief from royalty method. Under this method, an intangible asset’s fair value is equal to the present value of the estimated after-tax royalty savings generated over the life of the assets. Royalty rates were selected based on market review of third-party licensing arrangements. The fair value of the contingent consideration was valued based on a Monte-Carlo simulation of HGE’s estimated future revenue and earnings before interest, taxes, depreciation and amortization, discounted to its present value. The rate used to discount the estimated future net cash flows to their present values for each intangible asset was based upon a weighted average cost of capital calculation. The discount rate was determined after consideration of market rates of return on debt and equity capital, the weighted average return on invested capital and the risk associated with achieving forecasted sales related to the assets acquired from HGE. The amortization period for each of the intangible assets is 10 years. The intangible assets are being amortized on a straight-line basis, which is consistent with the pattern that the economic benefits of the intangible assets are expected to be utilized based upon estimated cash flows generated from such assets. Goodwill associated with the acquisition was primarily attributable to the expansion opportunity of the remote monitoring platform for respiratory patients and providers. The goodwill is deductible for tax purposes. The Company has included the financial results of HGE in the consolidated financial statements from the date of acquisition. The transaction costs associated with the acquisition were approximately $0.2 million and were recorded in general and administrative expense as incurred during 2020. The following table summarizes changes to the contingent consideration payable, a recurring Level 3 measurement, for the year ended December 31, 2021: Balance at December 31, 2020 $ 13,187 Change in value of contingent consideration based on correction of purchase price calculation (2,258 ) Change in fair value of contingent consideration (1,813 ) Balance at December 31, 2021 $ 9,116 Solus On February 28, 2019, the Company completed the acquisition of all outstanding equity securities of Solus, The following table summarizes the purchase price allocation that includes the fair values of the separately identifiable assets acquired and liabilities assumed as of February 28, 2019: Cash $ 466 Accounts receivable 411 Inventory 492 Prepaids and other current assets 3 Property and equipment 1 Goodwill 592 Intangible assets 455 Total assets acquired 2,420 Accounts payable and accrued expenses (241 ) Contract liabilities (75 ) Deferred taxes (78 ) Total liabilities assumed (394 ) Total purchase price $ 2,026 The excess of purchase consideration over the fair value of net tangible and identifiable intangible assets acquired was recorded as goodwill. The fair values assigned to tangible and identifiable intangible assets acquired and liabilities assumed are based on management’s estimates and assumptions as of the date of acquisition. In determining the purchase price allocation, the Company considered, among other factors, the opportunity provided by a customer agreement with the U.K. National Health Service. The fair value of the intangible assets associated with this agreement were estimated using a discounted cash flow method with the application of the multi-period excess earnings method. Under this method, an intangible asset’s fair value is equal to the present value of the incremental after-tax cash flows attributable to only the subject intangible assets after deducting contributory asset charges. An income and expenses forecast was built based upon specific intangible asset revenue and expense estimates. The rate used to discount the estimated future net cash flows to their present values for each intangible asset was based upon a weighted average cost of capital calculation. The discount rate was determined after consideration of market rates of return on debt and equity capital, the weighted average return on invested capital and the risk associated with achieving forecasted sales related to the assets acquired from Solus. The total weighted average amortization period for the intangible assets is approximately 3.83 years. The intangible assets are being amortized on a straight-line basis, which is consistent with the pattern that the economic benefits of the intangible assets are expected to be utilized based upon estimated cash flows generated from such assets. Goodwill associated with the acquisition was primarily attributable to the market expansion opportunity in the United Kingdom. The goodwill attributable to the United Kingdom jurisdiction is not deductible for tax purposes. The Company has included the financial results of Solus in the consolidated financial statements from the date of acquisition. The transaction costs associated with the acquisition were approximately $0.2 million and were recorded in general and administrative expense as incurred during 2019.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value Measurements In accordance with ASC 820, Fair Value Measurements and Disclosures, the Company generally defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). The Company uses a three-tier fair value hierarchy, which classifies the inputs used in measuring fair values. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements), and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are described below: • Level 1 – inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. • Level 2 – inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. If the asset or liability has a specified (contractual) term, a Level 2 input must be observable for substantially the full term of the asset or liability. • Level 3 – inputs are unobservable inputs for the asset or liability in which there is little, if any, market activity for the asset or liability at the measurement date. As of December 31, 2021 and 2020, the Company had two items, cash equivalents and contingent consideration, measured at fair value on a recurring basis. The Company’s cash equivalents primarily consist of money market deposits which total approximately $35.6 million and $90.3 million at December 31, 2021 and 2020, respectively, and are valued based on Level 1 of the fair value hierarchy. The Company’s contingent consideration which totals $9.1 million and $13.2 million at December 31, 2021 and 2020, respectively, relates to the 2020 acquisition of HGE and is valued based on Level 3 of the fair value hierarchy as described in Note 3 “Business Combinations.” During 2019, the Company granted warrants to purchase 19,790 shares of common stock in connection with an amendment to its financing arrangement described in Note 10 “Debt”. These equity-classified warrants were valued using the Black-Scholes pricing model, which falls within Level 3 of the fair value hierarchy. The assumptions used in the Black-Scholes pricing model were as follows at the date of grant: Expected dividend yield 0.0 % Risk free interest rate 2.4 % Expected stock price volatility 60.9 % Expected term (years) 10.0

Accounts Receivable

Accounts Receivable	12 Months Ended
	Dec. 31, 2021
Receivables [Abstract]
Accounts Receivable	5. Accounts Receivable Accounts receivable consists of the following: December 31, 2021 2020 United States $ 8,894 $ 18,893 International 2,147 4,967 Total accounts receivable 11,041 23,860 Less: Allowance for doubtful accounts (132 ) (372 ) Accounts receivable, net of allowance for doubtful accounts $ 10,909 $ 23,488 No individual customers accounted for 10% or more of revenue or accounts receivable as of or for the years ended December 31, 2021 or 2020.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2021
Inventory Disclosure [Abstract]
Inventories	6. Inventories Inventories consist of the following: December 31, 2021 2020 Component parts $ 19,860 $ 10,367 Finished goods 16,702 9,506 $ 36,562 $ 19,873

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2021
Property Plant And Equipment [Abstract]
Property and Equipment	7. Property and Equipment Property and equipment are carried at cost less accumulated depreciation and amortization. A summary of the components of property and equipment is as follows: December 31, 2021 2020 Equipment $ 1,576 $ 1,266 Furniture 1,387 1,320 Manufacturing equipment 14,318 10,658 Software 1,306 845 Demonstration, placements and evaluation units 19,109 16,116 Leasehold improvements 2,977 2,482 Construction in process 987 2,386 Total property and equipment 41,660 35,073 Less: Accumulated depreciation and amortization (19,503 ) (14,500 ) Total property and equipment, net $ 22,157 $ 20,573 Depreciation of property and equipment was $5.0 million, $4.6 million, and $3.0 million during the years ended December 31, 2021, 2020 and 2019, respectively.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	8. Goodwill and Intangible Assets The changes in the carrying amount of goodwill and intangible assets during 2020 and 2021 are as follows: Goodwill Intangible Assets Balance at December 31, 2019 $ 588 $ 353 Acquired during the period 15,620 5,520 Amortization - (183 ) Foreign currency exchange rate changes 18 4 Balance at December 31, 2020 16,226 5,694 Acquired during the period 1,302 - Change in value based on correction of purchase price calculation and allocation (2,222 ) (340 ) Amortization - (633 ) Impairment charge - (323 ) Foreign currency exchange rate changes (6 ) - Balance at December 31, 2021 $ 15,300 $ 4,398 The following table presents a summary of acquired intangible assets: As of December 31, 2021 Weighted Average Amortization Period in Years Gross Carrying Amount Accumulated Amortization Customer relationships 10.00 $ 2,420 $ (272 ) Developed technology 10.00 2,400 (271 ) Customer agreements 3.83 456 (335 ) Total intangible assets 9.47 $ 5,276 $ (878 ) The Company recognized $0.4 million, $0.1 million and $0.1 million of amortization expense within sales and marketing expenses related to the intangible assets during the years ended December 31, 2021, 2020 and 2019, respectively. The Company also recognized $0.2 million and less than $0.1 million of amortization expense within general and administrative expenses related to intangible assets during the years ended December 31, 2021 and 2020, respectively, with no such amounts being recorded within general and administrative expenses during the year ended December 31, 2019. The estimated amortization expense for intangible assets for future years is as follows: 2022 $ 603 2023 482 2024 482 2025 482 2026 482 Thereafter 1,867 Total $ 4,398

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities and Other Long-Term Liabilities	12 Months Ended
	Dec. 31, 2021
Payables And Accruals [Abstract]
Accrued Expenses and Other Current Liabilities and Other Long-Term Liabilities	9. Accrued Expenses and Other Current Liabilities and Other Long-Term Liabilities Accrued expenses and other current liabilities consist of the following: December 31, 2021 2020 Accrued bonuses $ 6,988 $ 6,584 Accrued commissions 5,181 11,689 Contingent consideration, current portion 3,952 5,322 Accrued payroll and employee-related costs 2,734 1,579 Operating lease liabilities, current portion 1,753 1,572 Accrued professional fees 1,682 1,156 Accrued taxes 1,450 1,717 Accrued inventory 1,111 1,423 Accrued vacation liability 786 793 Product warranty reserve 330 561 Other 2,592 1,637 Total accrued expenses and other current liabilities $ 28,559 $ 34,033 Other long-term liabilities consist of the following: December 31, 2021 2020 Contingent consideration $ 5,164 $ 7,865 Operating lease liabilities 5,357 6,779 Deferred payroll taxes - 572 Other - 13 Total other long-term liabilities $ 10,521 $ 15,229

Debt

Debt	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Debt	10. Debt Credit Facilities On October 21, 2020, the Company entered into a Loan and Security Agreement (the “CIBC Loan Agreement”) with Canadian Imperial Bank of Commerce Innovation Banking (“CIBC”) which provides for a revolving loan facility of $12.0 million (the “CIBC Revolving Facility”) and a term loan facility of $40.0 million (the “CIBC Term Facility” and, together with the CIBC Revolving Facility, the “CIBC Facilities”). The proceeds of the CIBC Facilities were used to repay the Company’s former revolving loan facility and term loan facility, described in more detail below. The CIBC Revolving Facility was scheduled to mature on October 21, 2022 and could be renewed on an annual basis thereafter by mutual agreement of the Company and CIBC. The Revolving Facility bore interest at a floating rate per annum equal to the Wall Street Journal (“WSJ”) Prime Rate plus 1.0% and is subject to a floor of 3.25%. At December 31, 2021, the interest rate was 4.25%. The outstanding balance under the CIBC Revolving Facility was $6.6 The Term Facility was scheduled to mature on October 21, 2025. Advances under the Term Facility bore interest at a floating rate per annum equal to the WSJ Prime Rate plus 2.5% and is subject to a floor of 3.25%. At December 31, 2021, the interest rate was 5.75%. The outstanding balance was $40.0 million at December 31, 2021. The CIBC Loan Agreement provided for interest-only payments on the CIBC Term Facility for the first 36 months through October 21, 2023. Thereafter, amortization payments on the CIBC Term Facility were to be payable monthly in 24 equal installments. prepayment occur red after October 21, 2022 but on or prior to October 21, 2023. The CIBC Facilit ies were secured by a lien on substantially all of the Company’s assets, including intellectual property. The CIBC Loan Agreement contained customary covenants and representations, including, without limitation, a minimum revenue covenant equal to 80% of each year’s annual operating plan (tested on a trailing twelve month basis at the end of each fiscal quarter) and other financial covenants, reporting obligations, and limitations on dispositions, changes in business or ownership, mergers or acquisitions, indebtedness, encumbrances, distributions and investments, transactions with affiliates and capital expenditures. The events of default under the Loan Agreement included, without limitation, and subject to customary grace periods, (1) the Company’s failure to make any payments of principal or interest under the Loan Agreement or other loan documents, (2) the Company’s breach or default in the performance of any covenant under the Loan Agreement, (3) the occurrence of a material adverse effect or an event that is reasonably likely to result in a material adverse effect, (4) the existence of an attachment or levy on a material portion of funds of the Company or its subsidiaries, (5) the Company’s insolvency or bankruptcy, or (6) the occurrence of certain material defaults with respect to any other of the Company’s indebtedness in excess of $500,000. If an event of default occurs, CIBC is entitled to take enforcement action, including acceleration of amounts due under the Loan Agreement. The CIBC Loan Agreement also contained other customary provisions, such as expense reimbursement and confidentiality. CIBC had indemnification rights and the right to assign the Facilities, subject to customary restrictions. As of December 31, 2021, the Company was in compliance with all covenants under the Loan Agreement. The annual principal maturities of the Company’s CIBC Term Facility as of December 31, 2021 was as follows: Total Due Years Ended December 31, 2022 $ - 2023 3,200 2024 19,200 2025 17,600 Less: Unamortized deferred financing costs (274 ) Long-term loans payable $ 39,726 As described in Note 20 “Subsequent Event”, the Company refinanced the CIBC Facilities on February 18, 2022. Prior Credit Facilities On October 21, 2020, the Company used $40 million of the CIBC Term Facility, approximately $4.9 million of the CIBC Revolving Facility, and approximately $6.3 million of cash on hand to pay off all obligations owing under, and to terminate, both its prior Credit Agreement and Guaranty, as amended (the “Amended Credit Agreement and Guaranty”), with Perceptive Credit Holdings II, LP (“Perceptive”) and its Business Financing Agreement, as amended (the “Amended Revolver Agreement”) with Western Alliance Bank. As a result of the termination of the Amended Credit Agreement and Guaranty and the Amended Revolver Agreement, the Company recorded a loss on extinguishment of debt of $4.2 million, which included the prepayment penalty, exit fees, write-off of the remaining unamortized deferred financing costs, and legal fees, during the fourth quarter of 2020.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	11. Commitments and Contingencies Lease Commitments In May 2016, the Company entered into a lease agreement for office and storage space at 100 Domain Drive, Exeter New Hampshire and has entered into several amendments since then to lease additional space. In total, the Company occupies approximately 95,320 square feet of space at this facility and the lease, as most recently amended, is scheduled to expire on January 28, 2025. The Company has the option to renew the lease for two additional five year terms by providing written notice twelve months prior to end of the initial or first lease extension term. The Company is not reasonably certain that it will renew the lease beyond January 2025. In October 2019, the Company entered into an assignation and variation agreement for a lease of 453 square meters of office and warehouse space at 2 Dryden Loan, Bilston Glen Industrial Estate, Loanhead in the United Kingdom. The lease term, as amended, expires on February 15, 2027. In November 2020, in connection with the acquisition of HGE, the Company assumed a real estate lease for 22,524 square feet of office space at 1301 Virginia Drive, Fort Washington, Pennsylvania. The lease term expires on July 31, 2025. The Company has the option to renew the lease for one additional five-year In November 2021, in connection with the acquisition of PCI, the Company assumed a real estate lease for 4,790 square feet of medical office space at 2832 and 2834 E. 101 st The Company has the option to renew the lease for two additional five year terms. In November 2021, the Company entered into a lease agreement, which is expected to commence in February 2022, where the Company will lease 23,877 square feet of manufacturing and warehouse space in Mesquite, Texas. The Company will lease this space under a lease expected to expire on March 31, 2027, with a renewal option for an additional five-year The following table presents operating lease cost and information related to operating right-of-use assets and operating lease liabilities: Year Ended December 31, 2021 2020 Lease cost: Operating lease cost $ 2,461 $ 1,717 Variable lease cost 475 379 Total $ 2,936 $ 2,096 Operating cash flow impacts: Cash paid for amounts included in measurement of lease liabilities $ 2,460 $ 1,731 Operating right of use assets obtained in exchange for new operating lease liabilities $ 549 $ 2,965 Weighted average remaining lease term - operating leases 3.3 years 4.2 years Weighted average discount rate - operating leases 8.1 % 8.0 % As of December 31, 2021, future maturities of lease liabilities under the Company’s noncancelable operating leases are as follows: Total Due Years Ended December 31, 2022 $ 2,255 2023 2,523 2024 2,562 2025 662 2026 113 Thereafter 5 Total payments 8,120 Less interest 1,010 Total present value of lease payments $ 7,110 Rent expense for the year ended December 31, 2019 was $2.0 million and was recorded in accordance with ASC 840. Legal Matters From time to time, the Company may become involved in various legal proceedings, including those that may arise in the ordinary course of business. The Company believes there is no litigation pending that could have, individually, or in the aggregate, a material adverse effect on the results of its operations or financial condition. During 2019, the Company settled litigation with a former supplier. The parties reached a settlement agreement on December 16, 2019 whereby the supplier agreed to pay the Company $0.65 million in a series of monthly payments through December 2021, and both the Company and the supplier agreed to release each from any other outstanding claims, which included $0.5 million of accounts payable the Company had previously recorded. As a result, the Company recorded a gain of $1.2 million in the consolidated statement of comprehensive loss during the fourth quarter of 2019. Other Commitments The Company has non-cancellable purchase commitments for inventories, capital equipment and services which total $3.7 million at December 31, 2021, all of which are expected to be paid within one year.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Stockholders' Equity	12. Stockholders’ Equity Preferred Stock As of December 31, 2021 and 2020, the Company has authorized 25,000,000 shares of preferred stock, at a par value of $0.001. As of December 31, 2021 and 2020, there are no shares of preferred stock outstanding. Common Stock As of December 31, 2021 and 2020, the Company has authorized 175,000,000 shares of common stock. The Company has 26,126,253 and 25,722,984 issued and outstanding

Warrants

Warrants	12 Months Ended
	Dec. 31, 2021
Warrants And Rights Note Disclosure [Abstract]
Warrants	13. Warrants The table below sets forth the Company’s warrant activity for the year ended December 31, 2020 and 2021: Number of Shares Weighted Average Exercise Price Outstanding at December 31, 2019 182,076 $ 14.84 Warrants granted - - Warrants exercised (148,128 ) 15.04 Outstanding at December 31, 2020 33,948 $ 14.00 Warrants granted - - Warrants exercised - - Outstanding at December 31, 2021 33,948 $ 14.00 All of the Company’s warrants outstanding at December 31, 2021 have an exercise price of $14.00 and expire at periods ranging from March 14, 2022 through July 28, 2025. On June 10, 2020, a warrant to purchase 80,097 shares of common stock was exercised on a net exercise basis. Upon exercise, the exercise price of $15.92 per share was satisfied through the Company’s withholding of 39,031 of the warrant shares and issuing 41,066 shares of common stock. On July 10, 2020, a warrant to purchase 20,889 shares of common stock held was exercised on a net exercise basis. Upon exercise, the exercise price of $ 14.00 per share was satisfied through the Company’s withholding of 6,902 of the warrant shares and issuing shares of common stock to the holder. On August 7, 2020, a warrant to purchase 4,285 shares of common stock held was exercised on a net exercise basis. Upon exercise, the exercise price of $ 14.00 per share was satisfied through the Company’s withholding of 2,064 of the warrant shares and issuing 2,221 shares of common stock to the holder. On October 1, 2020, a warrant to purchase 42,857 shares of common stock held was exercised on a net exercise basis. Upon exercise, the exercise price of $ 14.00 per share was satisfied through the Company’s withholding of 20,689 of the warrant shares and issuing 22,168 shares of common stock to the holder.

Disaggregated Revenue

Disaggregated Revenue	12 Months Ended
	Dec. 31, 2021
Revenue From Contract With Customer [Abstract]
Disaggregated Revenue	14. Disaggregated Revenue The following table shows the Company’s net revenue disaggregated into categories the Company considers meaningful: For the Year Ended December 31, 2021 US International Total Net revenue by: Product Revenue Capital Equipment $ 22,549 $ 11,117 $ 33,666 Disposables 50,764 15,867 66,631 Subtotal Product Revenue 73,313 26,984 100,297 Lease Revenue Capital Equipment 4,087 234 $ 4,321 Other 1,691 418 $ 2,109 Service and Other Revenue 5,056 1,509 6,565 Net Revenue $ 84,147 $ 29,145 $ 113,292 For the Year Ended December 31, 2020 US International Total Net revenue by: Product Revenue Capital Equipment $ 45,464 $ 12,719 $ 58,183 Disposables 44,548 12,163 56,711 Subtotal Product Revenue 90,012 24,882 114,894 Lease Revenue Capital Equipment 5,698 72 $ 5,770 Other 1,659 352 $ 2,011 Service and Other Revenue 1,792 1,266 3,058 Net Revenue $ 99,161 $ 26,572 $ 125,733 For the Year Ended December 31, 2019 US International Total Net revenue by: Product Revenue Capital Equipment $ 6,144 $ 3,180 $ 9,324 Disposables 27,753 7,302 35,055 Subtotal Product Revenue 33,897 10,482 44,379 Lease Revenue 1,721 - 1,721 Service and Other Revenue 965 1,039 2,004 Net Revenue $ 36,583 $ 11,521 $ 48,104 United States and International net revenue is based on the customer location to which the product is shipped. No individual foreign country represents more than 10% of the Company’s aggregated revenue. Contract Balances from Contracts with Customers Contract liabilities consist of deferred revenue and other contract liabilities associated with rebates and fees payable to GPOs, IDNs and distributor partners. Deferred revenues are included in contract liabilities in the accompanying consolidated balance sheets. The following table presents changes in contract liabilities during 2020 and 2021: Deferred Revenue Other Contract Liabilities Balance at December 31, 2019 $ 344 $ 137 Additions 3,137 459 Subtractions (963 ) (137 ) Balance at December 31, 2020 $ 2,518 $ 459 Additions 7,430 369 Subtractions (8,236 ) (459 ) Balance at December 31, 2021 $ 1,712 $ 369

Stock Plans and Stock-Based Com

Stock Plans and Stock-Based Compensation	12 Months Ended
	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Plans and Stock-Based Compensation	15. Stock Plans and Stock-Based Compensation On October 30, 2018, the Company’s Board of Directors adopted, and stockholders approved, the Vapotherm, Inc. 2018 Equity Incentive Plan (as amended, the “2018 Equity Plan”) which provides for the grant of stock options, stock appreciation rights, restricted and unrestricted stock and stock units, performance awards, and other awards that are convertible into or otherwise based on the Company’s common stock. In April 2021, the Company’s Board of Directors amended the 2018 Equity Plan to provide for double-trigger vesting in the event of a change in control (as defined in the 2018 Equity Plan). On January 23, 2019, the Company established a French Qualifying Subplan, which allows for the granting of stock options to purchase shares of common stock for employees and officers who are residents of France, and on August 31, 2020, the Company established a French Qualifying Subplan, which allows for the granting of not only stock options to purchase shares of common stock but also restricted stock units for employees and officers who are residents of France, and superseded and replaced the prior subplan. The options and restricted stock unit awards under the French Qualifying Subplan reside under the umbrella of the 2018 Equity Plan. Subject to customary anti-dilution adjustments, the number of shares of common stock that may be issued in satisfaction of awards under the 2018 Equity Plan was initially 998,900 shares, plus the number of shares (which will not exceed 769,419 shares) underlying awards under the Vapotherm, Inc. 2015 Stock Incentive Plan (the “2015 Equity Plan”), which plan was replaced by the 2018 Equity Plan, that, on or after the effectiveness of the 2018 Equity Plan, expire or are terminated, surrendered or cancelled without the delivery of shares, are forfeited to or repurchased by the Company, or otherwise become available again for grant under the 2015 Equity Plan. In addition, the number of shares of common stock available for issuance under the 2018 Equity Plan is increased on the first day of each calendar year beginning January 1, 2019 and each year thereafter until 2028 by the lesser of (i) four percent of the number of outstanding shares of common stock as of the close of business on the immediately preceding December 31 or (ii) the number of shares determined by the Board of Directors on or prior to such date. As of December 31, 2021, 1,239,402 shares of common stock remain available for issuance under the 2018 Equity Plan. To date, stock options, performance awards, restricted stock awards and restricted stock units have been issued under the 2018 Equity Plan. Stock-based compensation expense was allocated based on the employees’ and non-employees’ functions as follows: Year Ended December 31, 2021 2020 2019 Cost of revenue $ 729 $ 351 $ 187 Research and development 1,187 843 405 Sales and marketing 3,171 2,115 782 General and administrative 4,679 3,121 2,462 Total $ 9,766 $ 6,430 $ 3,836 During the years ended December 31, 2021, 2020 and 2019, the Company granted 18,098, 19,387 and 17,644 shares of its common stock, respectively, to members of its Board of Directors and consultants under the 2018 Equity Plan that were valued at the closing price of the Company’s common stock at the date of grant and were fully vested on the date of grant. During the fourth quarter of 2021, the Company elected to modify certain outstanding option awards which resulted in the recognition of additional compensation expense of $ 0.1 million. Stock Options Under the terms of the 2018 Equity Plan, the exercise price of the options is determined by the Board of Directors at the time of grant. Options granted under the 2018 Equity Plan and prior plans, including the 2015 Equity Plan, vest ratably over a period of one to four years from the date of grant and are exercisable over a period of not more than ten years from the date of grant. Stock option activity for the year ended December 31, 2021 is as follows: Weighted Number of Weighted Average Underlying Average Remaining Aggregate Common Exercise Contractual Intrinsic Shares Price Term Value Outstanding at December 31, 2020 1,766,337 $ 12.15 8.32 $ 26,294 Options granted 466,390 26.30 Options exercised (168,289 ) 8.97 Options canceled (139,704 ) 17.68 Outstanding at December 31, 2021 1,924,734 $ 15.46 7.82 $ 13,071 Exercisable at December 31, 2021 900,763 $ 11.40 7.13 $ 8,606 Vested and unvested expected to vest at December 31, 2021 1,924,734 $ 15.46 7.82 $ 13,071 The weighted average grant date fair value of options granted during the years ended December 31, 2021, 2020 and 2019 was $18.97, $9.90, and $9.20 per share, respectively. The aggregate intrinsic value of options exercised during the year ended December 31, 2021, 2020 and 2019 was $3.3 million, $6.8 million and $2.3 million, respectively. As of December 31, 2021, the Company had unrecognized stock-based compensation expense related to its unvested stock options awards of $10.2 Certain members of the Company’s management elected to receive their option grants in the form of restricted stock, which contains vesting provisions. Upon election of restricted stock, the Company records a liability for the unvested portion of the grant. As the restricted stock vests, the Company reclassifies the liability into additional paid-in capital. During the first quarter of 2019, the Company modified certain previously granted performance awards where the performance condition had not been met. The modification resulted in the granting of 68,526 shares of restricted stock for which 25% was immediately vested with the remaining portion vesting over 36 months. During 2016, the Company permitted the exercise of 79,865 stock options via nonrecourse notes. There were no exercises of stock options via nonrecourse notes in 2019, 2020 or 2021. The nonrecourse notes were fully paid during 2019 and the related shares were issued. The weighted average assumptions used in the Black-Scholes options pricing model are as follows: Year Ended December 31, 2021 2020 2019 Expected dividend yield 0.0 % 0.0 % 0.0 % Risk free interest rate 0.7 % 1.6 % 1.9 % Expected stock price volatility 86.6 % 87.6 % 64.5 % Expected term (years) 6.1 6.1 6.2 The Company assumed an average forfeiture rate of 4.17%, 4.17% and 6.73% for the years ended December 31, 2021, 2020 and 2019, respectively, based on historical experience with pre-vested forfeitures. Restricted Stock Units and Restricted Stock Awards The Company has granted both restricted stock units and restricted stock awards. A summary of restricted stock unit activity for the year ended December 31, 2021 is as follows: Weighted Average Grant Date Shares Fair Value Unvested at December 31, 2020 228,489 $ 25.60 Granted 364,632 24.69 Vested (45,908 ) 28.96 Canceled (37,825 ) 25.03 Unvested at December 31, 2021 509,388 $ 24.69 A summary of restricted stock award activity for the year ended December 31, 2021 is as follows: Weighted Average Grant Date Shares Fair Value Unvested at December 31, 2020 103,650 $ 1.68 Granted/purchased - - Vested (95,661 ) 1.68 Canceled - - Unvested at December 31, 2021 7,989 $ 1.68 As of December 31, 2021, the Company had unrecognized stock-based compensation expense related to its unvested restricted stock units and awards of $8.6 million, which is expected to be recognized over the remaining weighted average vesting period of 2.2 years. Employee Stock Purchase Plan Subject to customary anti-dilution adjustments, the number of shares of common stock that are available for issuance under the ESPP was initially 166,500 shares. The number of shares of common stock available for issuance under the ESPP is increased on the first day of each calendar year beginning January 1, 2019 and each year thereafter until 2028 by the lesser of (i) 1% of the number of shares of common stock issued and outstanding on the immediately preceding December 31, or (ii) the number of shares of common stock determined by the Board of Directors up to such an initial maximum of 1,741,300 shares of common stock. The number of shares of common stock reserved under the plan at December 31, 2021 totals 673,258. The ESPP provides for successive discrete offering periods of approximately six months or as determined by the plan administrator. The first offering period began on January 2, 2020 and ended on May 14, 2020. Subsequent offering periods began on each November 15 th th st st The ESPP permits eligible employees to elect to purchase shares of common stock through fixed whole percentage contributions from eligible compensation during each offering period, not to exceed 10% of the eligible compensation a participant receives during an offering period and not to accrue at a rate which exceeds $25,000 of the fair value of the stock (determined on the grant date(s)) for each calendar year. A participant may purchase the lower of (a) a number of shares of common stock determined by dividing such participant’s accumulated payroll deductions on the exercise date by the option price, (b) 5,000 shares, or (c) such other lesser maximum number of shares as shall have been established by the plan administrator. Amounts deducted and accumulated by the participant will be used to purchase shares of common stock at the end of each offering period. The purchase price of the shares will be 85% of the lower of the fair value of common stock on the first trading day of each offering period or on the purchase date. Participants may end their participation during an offering period up to ten days in advance of the exercise date and will be paid their accumulated contributions that have not been used to purchase shares of common stock. Participation ends automatically upon termination of employment. The fair value of the purchase right for the ESPP option is estimated on the date of grant using the Black-Scholes pricing model with the following assumptions: Year Ended December 31, 2021 2020 Expected dividend yield 0.0% 0.0% Risk free interest rate 0.2% 0.1% - 1.6% Expected stock price volatility 55.0% 93.0% - 131.0% Expected term (years) 0.5 0.4 - 0.5

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	16. Income Taxes Net loss before income taxes is as follows: Year Ended December 31, 2021 2020 2019 United States $ (59,973 ) $ (51,591 ) $ (50,343 ) United Kingdom 73 89 (862 ) Germany 24 - - $ (59,876 ) $ (51,502 ) $ (51,205 ) During the years ended December 31, 2021 and 2019, the Company recorded a tax benefit of approximately $0.1 million primarily related to foreign net deferred income tax assets deemed more likely than not to be realized in the United Kingdom. During the year ended December 31, 2020, the Company did not record any income tax expense or benefit because the Company has historically incurred operating losses and maintains a full valuation allowance against its United States net deferred tax assets. No tax benefit or provision was recorded on its United States results in any of the years ended December 31, 2021, 2020 or 2019. The reported amount of income tax benefit for each of 2021, 2020 and 2019 differs from the amount that would result from applying domestic federal statutory tax rates to pretax losses primarily because of changes in the valuation allowance and various permanent differences. A reconciliation of income tax expense is computed as the statutory federal income tax rate to income taxes as reflected in the financial statement as follows: Year Ended December 31, 2021 2020 2019 Federal income tax benefit at statutory rate (21.0 %) (21.0 %) (21.0 %) Permanent differences (5.4 %) (5.9 %) (6.7 )% Change in valuation allowance 26.9 % 26.8 % 26.9 % Other (0.6 %) 0.1 % 0.5 % Income tax expense (0.1 %) 0.0 % (0.3 %) Significant components of the Company’s net deferred tax assets and liabilities are as follows: December 31, 2021 2020 Deferred Tax Assets Net operating loss carryforwards $ 69,579 $ 59,779 Deduction of research and development costs 9,945 8,356 Tax credit carryforwards 6,068 5,109 Accrued expenses 4,425 2,997 Operating lease liabilities 1,771 2,300 Stock option expense attributed to non-ISO stock 3,473 1,641 Accrued bonus and vacation 2,065 1,693 Inventory valuation reserves 117 136 Deferred revenue 281 - Accounts receivable allowance 105 100 Accrued warranty 89 151 Intangible assets 7 - Other temporary differences 684 561 Gross deferred tax assets 98,609 82,823 Less: Valuation allowance (95,309 ) (79,236 ) Deferred tax assets after valuation allowance 3,300 3,587 Deferred Tax Liabilities Depreciation (1,468 ) (1,220 ) Intangible assets - (28 ) Operating lease right of use assets (1,754 ) (2,300 ) Deferred revenue - (45 ) Gross deferred tax liabilities (3,222 ) (3,593 ) Net Deferred Tax Assets (Liabilities) $ 78 $ (6 ) The Company’s major tax jurisdictions are the states of New Hampshire and Pennsylvania, and the United States, United Kingdom, and Germany. As of December 31, 2021, the Company had federal and state net operating loss carryforwards of $293.3 million and $137.5 million, respectively, which begin to expire in 2022. Federal net operating loss carryforwards generated during or after the year ended December 31, 2018 will carryforward indefinitely. As of December 31, 2021, the Company had federal research and development tax credits carryforwards of $5.9 million which begin to expire in 2022. Management of the Company has evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets generated from its UK subsidiary, which are comprised principally of net operating loss carryforwards. Under the applicable accounting standards management has concluded that the Company will realize the benefit of the subsidiary’s deferred tax asset. Management of the Company has evaluated the positive and negative evidence bearing upon the realizability of its domestic deferred tax assets, which are comprised principally of net operating loss carryforwards and research and development credits. Under the applicable accounting standards, management has considered the Company’s history of losses and concluded that it is more likely than not that the Company will not recognize the benefits of federal and state deferred tax assets. Accordingly, a valuation allowance of $95.3 million and $79.2 million has been established at December 31, 2021 and 2020, respectively. The valuation allowance increased $16.1 million during the year ended December 31, 2021, due primarily to net operating losses generated. Years prior to 2018 are generally closed due to statute of limitations for purposes of taxing jurisdictions assessing additional tax; however, the tax attributes, including net operating losses and research credits, from such years can still be reviewed and reduced upon audit. Years beginning in 2018 remain open to examination for both federal and state purposes. The Company accounts for uncertain tax positions pursuant to ASC 740, Income Taxes, which prescribes a recognition threshold and measurement process for financial statement recognition of uncertain tax positions taken or expected to be taken in a tax return. If the tax position meets this threshold, the benefit to be recognized is measured as the tax benefit having the highest likelihood of being realized upon ultimate settlement with the taxing authority. The Company recognizes interest accrued related to unrecognized tax benefits and penalties in the provision for income taxes. Management is not aware of any uncertain tax positions. As of December 31, 2021, and 2020, the Company determined that there were no liabilities associated with uncertain tax positions and no related interest and penalties. The Company’s policy is to recognize interest and penalties related to income tax matters as a component of income taxes, when and if incurred. Utilization of the net operating loss and tax credit carryforwards may be subject to a substantial annual limitation under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended (the “Code”) due to ownership change limitations that have occurred previously or that could occur in the future. These ownership changes may limit the amount of net operating loss and tax credit carryforwards that can be utilized to offset future taxable income and reduce taxes, respectively. The Company has not currently completed an evaluation of ownership changes through December 31, 2021 to assess whether utilization of the Company’s net operating loss and tax credit carryforwards would be subject to an annual limitation under Sections 382 and 383 of the Code. To the extent an ownership change is determined to have occurred under Sections 382 and 383 of the Code, the net operating loss and tax credit carryforwards may be subject to limitation.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Net Loss Per Share	17. Net Loss Per Share The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect: Year Ended December 31, 2021 2020 2019 Options to purchase common stock 1,924,734 1,766,337 1,030,148 Unvested restricted stock units and awards 517,377 332,139 229,913 Employee stock purchase plan shares - 43,595 - Warrants to purchase common stock 33,948 33,948 182,076 2,476,059 2,176,019 1,442,137

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2021
Related Party Transactions [Abstract]
Related Party Transactions	18. Related Party Transactions The Company recorded sales of $1.2 million for the year ended December 31, 2021 to an entity in which a member of the Company’s board of directors holds a management position. There were no outstanding balances due from that entity at December 31, 2021. See Note 10 “Debt” for a discussion of the Company’s Amended Credit Agreement and Guaranty and related transactions with Perceptive, a former holder of more than 5% of the Company’s common stock.

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2021
Compensation And Retirement Disclosure [Abstract]
Employee Benefit Plan	19. Employee Benefit Plan The Company has a 401(k) retirement plan (the “401(k) Plan”) for the benefit of eligible employees, as defined. Each participant may elect to contribute up to 100% of his or her compensation to the 401(k) Plan each year, subject to certain Internal Revenue Service limitations. The Company matches employee contributions at a rate of 100% of the first 6% of employee contributions During 2019, the Company matched employee contributions at a rate of 50% of the first 4% of employee contributions, and the employer match was capped at $1,000 per year for employees with annual earnings less than $50,000 and $500 per year for employees with annual earnings greater than $50,000. In 2020 and 2021, the employer match was capped at $1,000 and $2,000 , respectively, per year for all employees. The Company contributed $0.6 million, $0.3 million and $0.1 million during the years ended December 31, 2021, 2020 and 2019, respectively.

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2021
Subsequent Events [Abstract]
Subsequent Event	20. Subsequent Event On February 18, 2022 (“the Effective Date”), the Company entered into a Loan and Security Agreement (the “Loan Agreement”) with SLR Investment Corporation (“SLR”) which provides for a term loan A facility of $100.0 million (the “Term Loan A Facility”) and a term loan B facility of $25.0 million (the “Term Loan B Facility” and, together with the Term Loan A Facility, the “Facilities”). The Term Loan A Facility was funded to the Company on the Effective Date. The Term Loan B Facility will be available to the Company following the Effective Date upon achievement of a certain minimum revenue level as more fully described in the Loan Agreement. The proceeds of Term Loan A Facility were used to repay all indebtedness under the CIBC Loan Agreement. The Facilities will mature on February 1, 2027. Advances under the Facilities bear interest at a floating rate per annum equal to (a) the greater of (i) 0.10% and (ii) the LIBOR Rate, plus (b) 8.30%. The Loan Agreement provides for interest-only payments for the first forty-eight months following the Effective Date. Thereafter, amortization payments on the Facilities will be payable monthly in twenty-four equal installments; provided that the Company shall have the option to extend the interest-only period for an additional twelve months upon achievement of a certain minimum revenue level as more fully described in the Loan Agreement. The Facilities are secured by a lien on substantially all of the assets, including intellectual property, of the Company. The Loan Agreement contains customary covenants and representations, including, without limitation, a minimum revenue covenant equal to 75% of each month’s forecasted net product revenue (tested on a trailing six month basis at the end of each fiscal month, commencing with the six month period ending on July 31, 2022) and other financial covenants, reporting obligations, and limitations on dispositions, changes in business or ownership, mergers or acquisitions, indebtedness, encumbrances, distributions and investments, transactions with affiliates and capital expenditures. The events of default under the Loan Agreement include, without limitation, and subject to customary grace periods, (1) the Company’s failure to make any payments of principal or interest under the Loan Agreement or other loan documents, (2) the Company’s breach or default in the performance of any covenant under the Loan Agreement, (3) the occurrence of a material adverse effect or an event that is reasonably likely to result in a material adverse effect, (4) the existence of an attachment or levy on a material portion of the Company’s funds or of its subsidiaries, (5) the Company’s insolvency or bankruptcy, or (6) the occurrence of certain material defaults with respect to any other of the Company’s indebtedness in excess of $500,000. If an event of default occurs, SLR is entitled to take enforcement action, including acceleration of amounts due under the Loan Agreement. The Loan Agreement also contains other customary provisions, such as expense reimbursement and confidentiality. SLR has indemnification rights and the right to assign the Facilities, subject to customary restrictions. On February 18, 2022, the Company utilized approximately $47.4 million of the Term Loan A Facility to pay off all obligations owing under to pay off all obligations owing under, and to terminate the CIBC Facilities.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”).
Principles of Consolidation	Principles of Consolidation These consolidated financial statements include the financial statements of Solus Medical Ltd. (“Solus”), a wholly owned subsidiary of the Company based in the United Kingdom, HGE, a wholly owned subsidiary of the Company located in the United States, Vapotherm Deutschland GmbH, a wholly owned subsidiary of the Company located in Germany, and PCI and RespirCare, which were acquired by HGE in the fourth quarter of 2021. All intercompany accounts and transactions have been eliminated upon consolidation.
Segment Information	Segment Information Operating segments are defined as components of an enterprise for which separate discrete financial information is available and evaluated regularly by the chief operating decision maker in deciding how to allocate resources and in assessing performance. The Company globally manages the business within one reporting segment, Vapotherm, Inc. and three reporting units, Vapotherm, Solus and HGE. Segment information is consistent with how management reviews the business, makes investing and resource allocation decisions and assesses operating performance. The majority of the Company’s long-term assets are located in the United States. Long-term assets located outside the United States total $2.4 million and $0.2 million at December 31, 2021 and 2020, respectively.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires the Company to make judgments, assumptions, and estimates that affect the reported amounts of assets, liabilities, revenue and expenses, and the related disclosure of contingent assets and liabilities. The Company evaluates its estimates on an ongoing basis. The Company bases its estimates on historical experience and various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Significant estimates relied upon in preparing these consolidated financial statements include calculation of stock-based compensation, fair values of acquired assets and liabilities, including goodwill and intangibles assets, realizability of inventories, allowance for bad debts, accrued expenses, including the fair value of contingent consideration, the valuation allowances against deferred income tax assets, and assessments of impairment with respect to long-lived and intangible assets. Actual results may differ from these estimates.
Reclassification	Reclassification Certain amounts in 2020 and 2019 have been reclassified to conform to the presentation in 2021. None of the reclassifications had any impact to the Company’s results of operations.
Financial Instruments and Concentrations of Credit Risk	Financial Instruments and Concentrations of Credit Risk As of December 31, 2021 and 2020, the Company’s financial instruments were comprised of cash and cash equivalents, restricted cash, accounts receivable, accounts payable and debt, the carrying amounts of which approximated fair value due to the short-term nature or market interest rates. All of the Company’s cash and cash equivalents are maintained at creditworthy financial institutions. At December 31, 2021 and 2020, deposits exceed the amount of any insurance provided. The Company extends credit to customers in the normal course of business but typically does not require collateral or any other security to support amounts due. Management performs ongoing credit evaluations of its customers. An allowance for potentially uncollectible accounts is provided based on history, economic conditions, and composition of the accounts receivable aging. In some cases, the Company makes allowances for specific customers based on these and other factors. Provisions for the allowance for doubtful accounts are recorded in general and administrative expenses in the accompanying consolidated statements of comprehensive loss.
Supplier Risk	Supplier Risk The Company obtains some of the components and subassemblies included in its Precision Flow systems and obtains its Oxygen Assist Module from single source suppliers and the partial or complete loss of one or more of these suppliers could cause significant production delays, an inability to meet customer demand and a substantial loss in revenue.
Foreign Currency and Foreign Operations	Foreign Currency and Foreign Operations The functional currency of the Company is the currency of the primary economic environment in which the entity operates, which is the U.S. dollar. For the Company’s non-U.S. subsidiaries that transacts in a functional currency other than the U.S. dollar, assets and liabilities are translated at current rates of exchange at the balance sheet date. Income and expense items are translated at the average foreign currency exchange rates for the period. Adjustments resulting from the translation of the financial statements of its foreign operations into U.S. dollars are excluded from the determination of net loss and are recorded in accumulated other comprehensive income (loss), a separate component of stockholders’ equity. Realized foreign currency gains or losses arising from transactions denominated in foreign currencies are recorded in other (expense) income in the consolidated statements of comprehensive loss.
Cash, Cash Equivalents, and Restricted Cash	Cash, Cash Equivalents, and Restricted Cash The Company considers all highly liquid temporary investments purchased with original maturities of 90 days or less to be cash equivalents. The Company holds restricted cash related to certificates of deposits and collateral in relation to lease agreements. As of December 31, 2021, $1.1 million of the Company’s $57.3 million of cash, cash equivalents and restricted cash balance was located outside the United States. The following table presents the components of total cash, cash equivalents, and restricted cash as set forth in the Company’s consolidated statements of cash flows: December 31, 2021 2020 Cash and cash equivalents $ 57,071 $ 113,683 Restricted cash 253 1,853 Total cash, cash equivalents, and restricted cash $ 57,324 $ 115,536
Inventories	Inventories Inventories consist of finished goods and component parts and are valued at the lower of cost or net realizable value, determined by the first-in, first-out (“FIFO”) method. On a quarterly basis, the Company evaluates the carrying costs of both finished goods and component part items. To the extent that such costs exceed future demand estimates, exhibit historical turnover at rates less than current inventory levels, or exceed estimated selling prices less costs to sell, the Company reduces the carrying value of inventories to its net realizable value. The Company only capitalizes pre-launch inventories when purchased for commercial sale and it deems regulatory approval to be probable.
Public Offering Costs	Public Offering Costs The Company incurs public offering costs consisting of legal, accounting and other costs directly attributable to the Company’s public offerings and defers such costs until the closing of the offerings. Upon closing of offerings, such costs are netted against the proceeds received. As of December 31, 2021 and 2020, no amounts were deferred.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost. Depreciation is recognized over the estimated useful lives of the related assets on a straight-line basis, except for tooling for which depreciation is recognized utilizing the units-of-production method prospectively beginning on January 1, 2021. The Company changed to the units-of-production method to be tter reflect the pattern of economic consumption of the tooling. When impairment indicators are present, the Company evaluates the recoverability of its long-lived assets. If the assessment indicates an impairment, the affected assets are written down to fair value. There were no impairments of property and equipment during 2021, 2020, or 2019. Repairs and maintenance are expensed as incurred. Expenditures that increase the value or productive capacity of assets are capitalized. When property and equipment are retired, sold, or otherwise disposed of, the asset’s carrying amount and related accumulated depreciation are removed from the accounts and any gain or loss is included in operating expenses. The lives used in computing straight-line depreciation are as follows: Number of Years Equipment 3 - 7 Furniture 5 - 7 Manufacturing equipment 3 - 10 Software 2 - 3 Demonstration, placements and evaluation units 3 - 7 Leasehold improvements Lesser of life of lease or 10 years
Intangible Assets	Intangible Assets Intangible assets are related to customer relationships, developed technology, customer agreements, trademarks and trade names and are amortized on a straight-line basis over their useful lives. Amortization is recorded within sales and marketing expenses in the consolidated statements of comprehensive loss for customer-related intangible assets while amortization of other intangible assets is included within general and administrative expenses in the consolidated statements of comprehensive loss. Intangible assets are evaluated for impairment whenever events or circumstances indicate an asset may be impaired. During the fourth quarter of 2021, the Company recorded an impairment charge of $0.3 million related to trade names and trademarks no longer in use. There were no impairments of intangible assets during 2020 or 2019.
Goodwill	Goodwill Goodwill represents the difference between the purchase price and the fair value of the identifiable tangible and intangible net assets when accounted for using the purchase method of accounting in a business combination. Goodwill is not amortized but reviewed for impairment. Goodwill is reviewed annually, as of October 1, and whenever events or changes in circumstances indicate that the carrying value of the goodwill may not be recoverable. The Company compares the fair value of its reporting units to their carrying values. If the carrying value of the net assets assigned to a reporting unit exceeds the fair value of the reporting unit, the Company would record an impairment loss equal to the difference. There was no impairment of goodwill during 2021, 2020 or 2019.
Leases	Leases The Company’s operating leases primarily consist of real estate leases for office, manufacturing, research and development, and warehouse space, as well as certain vehicle and equipment leases. Prior to adopting ASU 2016-02, Leases (Topic 842) ASC 842 requires lessees to recognize leases on the balance sheet as a lease liability with a corresponding right-of-use asset, subject to certain permitted accounting policy elections. Under ASC 842, the Company determines whether a contract is or contains a lease at the inception of the contract. This determination is based on whether the contract provides the Company the right to control the use of a physically distinct asset and substantially all of the capacity of an asset. Leases with an initial noncancelable term of twelve months or less that do not include an option to purchase the underlying asset that the Company is reasonably certain to exercise are classified as short-term leases. The Company has elected as an accounting policy to exclude from the consolidated balance sheets the right-of-use assets and lease liabilities related to short-term leases. The Company recognizes rent expense for its operating leases on a straight-line basis over the term of the lease. Certain of the Company’s leases include options to extend or terminate the lease at its sole discretion. The Company does not consider in the measurement of right-of-use assets and lease liabilities an option to extend or terminate a lease if the Company is not reasonably certain to exercise the option. As of December 31, 2021, the Company has not included any options to extend its leases in its measurement of the related right-of-use assets or lease liabilities as the Company is not reasonably certain it will exercise the options. Certain of the Company’s leases include covenants that oblige the Company, at its sole expense, to repair and maintain the leased asset periodically during the lease term. The Company is not a party to any leases that contain residual value guarantees. Many of the Company’s leases include fixed and variable payments. Among other charges, variable payments related to real estate leases include real estate taxes, insurance, operating expenses, and common area maintenance, which are usually billed at actual amounts incurred proportionate to the Company’ rented square feet of the building. Variable payments related to vehicle and equipment leases relate to usage of the underlying asset, sales and use tax, and value-added tax. Variable payments that do not depend on an index or rate are expensed as incurred and are not included in the measurement of the lease liability. In accordance with the guidance in ASC 842, components of a lease should be split into three categories: lease components (e.g. buildings, vehicles, etc.), non-lease components (e.g. common area maintenance, consumables, etc.), and non-components (e.g. property taxes, insurance, etc.). The fixed and in-substance fixed contract consideration (including any related to non-components) must be allocated to the lease components and non-lease components based on their relative fair values. The Company elected the accounting policy to not separate lease and non-lease components for its real estate, vehicle, and equipment leases. Therefore, each lease component and the related non-lease components and non-components are accounted for together as a single component. The Company measures its lease liability for each leased asset as the present value of lease payments, as defined in ASC 842, discounted using a discount rate specific to the terms of the underlying lease. The Company’s right-of-use assets are equal to the related lease liabilities, adjusted for lease incentives received including tenant improvement allowances, initial direct costs incurred related to the lease, and payments made to the lessor prior to the lease commencement date. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company estimates its incremental borrowing rate for each leased asset based on the interest rate the Company would incur to borrow an amount equal to the lease payments on a collateralized basis over a similar term in a similar economic environment.
Contingent Consideration	Contingent Consideration Contingent consideration is initially recorded at its acquisition date fair value, is remeasured at each reporting date and is included in accrued expenses and other current liabilities and other long-term liabilities in the Company’s consolidated balance sheets. Fair value is estimated utilizing several key assumptions and is remeasured at each reporting period with changes in fair value being recorded as a component of general and administrative expense in the consolidated statements of comprehensive loss . See Note 3 “Business Combinations” for a rollforward of contingent consideration and Note 9 “Accrued Expenses and Other Current Liabilities and Other Long-Term Liabilities” for balances at December 31, 2021 and 2020.
Product Warranty	Product Warranty The Company provides its customers with a standard one-year Balance at December 31, 2019 $ 225 Provisions for warranty obligations 636 Settlements (300 ) Balance at December 31, 2020 561 Provisions for warranty obligations 205 Settlements (436 ) Balance at December 31, 2021 $ 330
Deferred Financing Costs	Deferred Financing Costs Direct financing costs are deferred and amortized as a component of interest expense, over the term of the related debt. The long-term portion of the balance of unamortized deferred financing costs related to Company’s term loan is presented as a reduction of the related borrowing arrangement liability and totals $0.3 million at each of December 31, 2021 and 2020. The unamortized deferred financing costs related to the Company’s revolving facility are recorded in prepaid expenses and other current assets in the Company’s consolidated balance sheet and totals less than $0.1 million at December 31, 2020. There were no unamortized deferred financing costs recorded in prepaid and other current assets at December 31, 2021.
Insurance	Insurance Effective January 1, 2020, the Company became self-insured for certain obligations related to health insurance. The Company also purchases stop-loss insurance to protect itself from material losses. Judgments and estimates are used in determining the potential value associated with reported claims and for events that have occurred but have not been reported. The Company’s estimates consider expected claim experience and other factors. Receivables for insurance recoveries are recorded as assets, on an undiscounted basis. The Company’s liabilities are based on estimates, and, while the Company believes that its accruals are adequate, the ultimate liability may be significantly different from the amounts recorded. Changes in claims experience, the Company’s ability to settle claims or other estimates and judgments used by management could have a material impact on the amount and timing of expense for any period.
Revenue Recognition	Revenue Recognition The Company’s revenue is primarily derived from the sale of products, leases and services. Product revenue consists of capital equipment and single-use disposables that are shipped and billed to customers both domestically and internationally. The Company’s main capital equipment products are the Precision Flow systems, the Vapotherm Transfer Unit 2.0 and Q50 compressor. The Company’s main disposable products are single-use disposables and nasal interfaces, or cannulas, and adaptors. Lease revenue consists of two components which include capital equipment that the Company leases to its customers and, in certain situations, an allocation from disposable revenue to other lease revenue upon the sale of disposable products in bundled arrangements involving the placement of Precision Flow capital units for use by the customer at no upfront charge in connection with the customer’s ongoing purchase of disposable products. Service revenue consists of fees associated with routine service of capital units and the sale of extended service contracts and preventative maintenance plans, which a re purchased by a small portion of the Company’s customer base. In addition, the Company sells small quantities of component parts in the United States, United Kingdom and to third-party international service centers who provide service on Precision Flow capital units outside of the United States and United Kingdom . Service revenue also includes fees from remote patient monitoring services sold through Vapotherm Access. Freight revenue is based upon actual freight costs plus a percentage markup of such costs associated with the shipment of products domestically, and to a lesser extent, internationally, and is included in service revenue. Rebates and fees consist of contractually obligated administrative fees and percentage-of-sales rebates paid to Group Purchasing Organizations (“GPOs”), Integrated Delivery Networks (“IDNs”) and distributor partners and accounted for as a reduction of revenue. Under the Financial Accounting Standard Board’s (“FASB”) Accounting Standards Codifications (“ASC”) 606, Revenue from Contracts with Customers (“ASC 606”), revenue is recognized when a customer obtains control of promised goods or services, in an amount that reflects the consideration which the Company expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of ASC 606, the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract and assesses whether each promised good or service is distinct and determines those that are performance obligations. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. Sales, value-added, and other taxes collected on behalf of third parties are excluded from revenue. The Company’s standard payment terms are generally 30 days from the date of sale. Contracts with customers may contain multiple performance obligations. For such arrangements, the transaction price is allocated to each performance obligation based on the estimated relative stand-alone selling prices of the promised products or services underlying each performance obligation. The Company determines stand-alone selling prices based on the price at which the performance obligation is sold separately. If the stand-alone selling price is not observable through past transactions, the Company estimates the stand-alone selling price taking into account available information such as market conditions and internally approved pricing guidelines related to the performance obligations. Revenue is generally recognized when the customer obtains control of the Company’s product, which generally occurs at a point in time upon shipment based on the contractual shipping terms of a contract. Product and service revenue is measured as the amount of consideration the Company expects to receive in exchange for transferring products or services to a customer. To the extent the transaction price includes variable consideration, the Company estimates the amount of variable consideration that should be included in the transaction price utilizing the expected value amount method to which the Company expects to be entitled. As such, revenue on sales is recorded net of prompt pay discounts and payments made to GPOs, IDNs and distributors. Variable consideration is included in the transaction price if, in the Company’s judgment, it is probable that a significant future reversal of cumulative revenue under the contract will not occur. Determination of whether to include estimated amounts in the transaction price is based largely on an assessment of the Company’s anticipated performance and all information (historical, current and forecasted) that is reasonably available. The Company believes that the estimates it has established are reasonable based upon current facts and circumstances. Applying different judgments to the same facts and circumstances could result in different estimates. When determining the transaction price of a contract, an adjustment is made if payment from a customer occurs either significantly before or significantly after performance, resulting in a significant financing component. Applying a practical expedient under ASC 606, the Company does not assess whether a significant financing component exists if the period between when the Company performs its obligations under the contract and when the customer pays is one year or less. None of the Company’s contracts contained a significant financing component during the years ended December 31, 2021, 2020 or 2019. The Company’s contracts with its customers have a duration of less than one year. Therefore, the Company has elected to apply a practical expedient and recognizes the incremental costs of obtaining contracts as an expense. These costs are included in sales and marketing expense in the accompanying consolidated statements of comprehensive loss.
Lease Revenue	Lease Revenue The Company also enters into agreements to lease its capital equipment. For such sales, the Company accounts for revenue under ASC 842 and assesses and classifies these transactions as sales-type or operating leases based on whether the lease transfers ownership of the equipment to the lessee by the end of the lease term. This criterion is met in situations in which the lease agreement provides for the transfer of title at or shortly after the end of the lease term. Equipment included in arrangements including transfer of title are accounted for as sales-type leases and the Company recognizes the present value of the lease payments due over the lease term as revenue at the inception of the lease. The Company records the present value of future lease payments in prepaid expenses and other current assets in the accompanying consolidated balance sheets ; these amounts totaled $ million and $ 2.7 million at December 31, 20 2 1 and 20 20 , respectively . Equipment included in arrangements that do not include the transfer of title, nor any of the sales-type or direct financing lease criteria, are accounted for as operating leases and revenue is recognized on a straight-line basis over the term of the lease. Prior to the adoption of ASC 842 effective January 1, 2020, the Company accounted for such transactions under ASC 840 and there was no change in the Company’s accounting for such transactions upon the adoption of ASC 842. The Company also enters into agreements involving the placement of Precision Flow capital units for use by the customer at no upfront charge in connection with the customer’s ongoing purchase of disposable products. In these bundled arrangements, revenue recognized for the sale of the disposables is allocated between disposable revenue and other lease revenue based on the estimated relative stand-alone selling prices of the individual performance obligations.
Shipping and Handling Costs	Shipping and Handling Costs Amounts billed to customers for shipping and handling are included in service revenue. Shipping and handling costs are included in costs of sales. The total costs of shipping and handling for the years ended December 31, 2021, 2020 and 2019 totaled $1.6 million, $2.5 million and $1.0 million, respectively.
Sales and Value-Added Taxes	Sales and Value-Added Taxes When required by local jurisdictions, the Company bills its customers for sales tax and value-added tax calculated on each sales invoice and records a liability for the sales and value-added tax payable, which is included in accrued expenses and other current liabilities in the consolidated balance sheets. Sales tax and value-added tax billed to a customer are not included in the Company’s revenue.
Research and Development Costs	Research and Development Costs Research and development costs are expensed when incurred and are related primarily to product design, prototype development and testing, the investigation of possible follow-on product enhancements and new product releases, and investigation of complementary technologies potentially available to enhance the Company’s offerings in the marketplace.
Stock-Based Compensation	Stock-Based Compensation The Company maintains an equity incentive plan to provide long-term incentives for employees, consultants, and members of the board of directors. The plan allows for the issuance of non-statutory and incentive stock options, restricted stock, unrestricted stock, stock units, including restricted stock units, and stock appreciation rights to employees, consultants and non-employee directors. The Company recognizes stock-based compensation expense for awards of equity instruments to employees and non-employees based on the grant date fair value of those awards in accordance with ASC Topic 718, Stock Compensation (“ASC 718”). ASC 718 requires all equity-based compensation awards, including grants of restricted shares and stock options, to be recognized as expense in the consolidated statements of comprehensive loss based on their grant date fair values. The fair value of each option grant is estimated on the grant date using the Black-Scholes option pricing model. The fair value of restricted stock and restricted stock units is measured at the market value of the related shares of the Company’s common stock on the grant date. The Company recognizes stock-based expense for shares of its common stock issued pursuant to the Vapotherm, Inc. 2018 Employee Stock Purchase Plan (“ESPP”) on a straight-line basis over the related offering period. The Company estimates the fair value of shares to be issued under the ESPP based on a combination of options valued Scholes option pricing model. The expected life is determined based on the contractual term. Dividend yield , risk-free interest rate, forfeiture rates and expected volatility are estimated in a manner similar to option grants described abo ve.
Net Income (Loss) per Share	Net Income (Loss) per Share Basic net income (loss) per share is computed by dividing the net income (loss) by the weighted average number of common shares outstanding for the period. Diluted net income (loss) per share is computed by dividing the net income (loss) by the weighted average number of common shares outstanding for the period, including potential dilutive common shares. For purpose of this calculation, outstanding options, unvested restricted stock units, unissued employee stock purchase plan shares, and warrants are considered potential dilutive common shares.
Income Tax	Income Tax The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the consolidated financial statements or in the Company’s tax returns. Deferred taxes are determined based on the difference between the financial reporting and tax basis of assets and liabilities using enacted tax rates in effect in the years in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies. The Company accounts for uncertainty in income taxes recognized in the consolidated financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the consolidated financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties.
Recently Adopted Accounting Pronouncements	Recently Issued Accounting Pronouncements The Jumpstart Our Business Startups Act (the “JOBS Act”) allows an emerging growth company (“EGC”) to delay adoption of new or revised accounting pronouncements applicable to public companies until such pronouncements were made applicable to private companies. Since the Company was an EGC prior to December 31, 2020, the Company had elected to use the adoption dates applicable to private companies. As a result, the Company’s consolidated financial statements may not be comparable to the financial statements of issuers who are required to comply with the effective date for new or revised accounting standards that are applicable to public companies. Since the Company no longer qualified as an EGC as of December 31, 2020, subsequent to that date, it adopts future accounting pronouncements at dates applicable to public companies. Credit Losses (Topic 326): In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). This standard requires that credit losses be reported using an expected losses model rather than the incurred losses model that is currently used and establishes additional disclosures related to credit risks. In November 2019, the FASB issued ASU 2019-10, Financial Instruments-Credit Losses (Topic 326), Derivative and Hedging (Topic 815) and Leases (Topic 842), which defers the effective date for ASU 2016-13 to interim and annual periods beginning after December 15, 2022 for private companies, EGCs following private company adoption dates, or public entities meeting the definition of smaller reporting companies as of the date of issuance of this update. Since the Company met the definition of an EGC following private company adoption dates at the time of issuance of this standard, the Company is not required to adopt ASU 2016-13 until January 1, 2023. The Company has not yet determined the effects, if any, that the adoption of ASU 2016-13 may have on its financial position, results of operations, cash flows, or disclosures .

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Components of Cash, Cash Equivalents and Restricted Cash	The following table presents the components of total cash, cash equivalents, and restricted cash as set forth in the Company’s consolidated statements of cash flows: December 31, 2021 2020 Cash and cash equivalents $ 57,071 $ 113,683 Restricted cash 253 1,853 Total cash, cash equivalents, and restricted cash $ 57,324 $ 115,536
Lives Used in Computing Straight-Line Depreciation	The lives used in computing straight-line depreciation are as follows: Number of Years Equipment 3 - 7 Furniture 5 - 7 Manufacturing equipment 3 - 10 Software 2 - 3 Demonstration, placements and evaluation units 3 - 7 Leasehold improvements Lesser of life of lease or 10 years
Summary of Roll-Forward Warranty Liability	A roll-forward of the Company’s warranty liability is as follows: Balance at December 31, 2019 $ 225 Provisions for warranty obligations 636 Settlements (300 ) Balance at December 31, 2020 561 Provisions for warranty obligations 205 Settlements (436 ) Balance at December 31, 2021 $ 330

Business Combinations (Tables)

Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2021
Business Combinations [Abstract]
Summary of Purchase Price Allocation	The purchase price, net of cash acquired, of $1.7 million was funded with cash payments of approximately $1.3 million and the settlement of $0.4 million of preexisting transactions. The acquisition has been accounted for as an acquisition of a business. The following table summarizes the preliminary purchase price allocation that includes the fair values of the separately identifiable assets acquired and liabilities assumed as of November 2, 2021: Cash $ 39 Accounts receivable 101 Prepaids and other current assets 11 Property and equipment 397 Operating lease right-of-use assets 316 Goodwill 1,302 Other long-term assets 9 Total assets acquired 2,175 Accounts payable (29 ) Other current liabilities (111 ) Other long-term liabilities (264 ) Total liabilities assumed (404 ) Total purchase price $ 1,771 The following table summarizes the final purchase price allocation that includes the fair values of the separately identifiable assets acquired and liabilities assumed as of November 13, 2020: Cash $ 2 Accounts receivable 518 Inventory 3 Prepaids and other current assets 238 Property and equipment 225 Operating lease right-of-use assets 2,329 Goodwill 13,398 Intangible assets 5,180 Other long-term assets 45 Total assets acquired 21,938 Accounts payable (32 ) Accrued expenses and other current liabilities (620 ) Contract liabilities (31 ) Other long-term liabilities (1,951 ) Total liabilities assumed (2,634 ) Total purchase price $ 19,304 Cash $ 466 Accounts receivable 411 Inventory 492 Prepaids and other current assets 3 Property and equipment 1 Goodwill 592 Intangible assets 455 Total assets acquired 2,420 Accounts payable and accrued expenses (241 ) Contract liabilities (75 ) Deferred taxes (78 ) Total liabilities assumed (394 ) Total purchase price $ 2,026
Summary of Changes to Contingent Consideration Payable	The following table summarizes changes to the contingent consideration payable, a recurring Level 3 measurement, for the year ended December 31, 2021: Balance at December 31, 2020 $ 13,187 Change in value of contingent consideration based on correction of purchase price calculation (2,258 ) Change in fair value of contingent consideration (1,813 ) Balance at December 31, 2021 $ 9,116

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2021
Warrants
Schedule of Assumptions Used in Black-Scholes Options Pricing Model at the Date of Grant	The assumptions used in the Black-Scholes pricing model were as follows at the date of grant: Expected dividend yield 0.0 % Risk free interest rate 2.4 % Expected stock price volatility 60.9 % Expected term (years) 10.0

Accounts Receivable (Tables)

Accounts Receivable (Tables)	12 Months Ended
	Dec. 31, 2021
Receivables [Abstract]
Summary of Accounts Receivable	Accounts receivable consists of the following: December 31, 2021 2020 United States $ 8,894 $ 18,893 International 2,147 4,967 Total accounts receivable 11,041 23,860 Less: Allowance for doubtful accounts (132 ) (372 ) Accounts receivable, net of allowance for doubtful accounts $ 10,909 $ 23,488

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2021
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories consist of the following: December 31, 2021 2020 Component parts $ 19,860 $ 10,367 Finished goods 16,702 9,506 $ 36,562 $ 19,873

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2021
Property Plant And Equipment [Abstract]
Summary of Components of Property and Equipment	Property and equipment are carried at cost less accumulated depreciation and amortization. A summary of the components of property and equipment is as follows: December 31, 2021 2020 Equipment $ 1,576 $ 1,266 Furniture 1,387 1,320 Manufacturing equipment 14,318 10,658 Software 1,306 845 Demonstration, placements and evaluation units 19,109 16,116 Leasehold improvements 2,977 2,482 Construction in process 987 2,386 Total property and equipment 41,660 35,073 Less: Accumulated depreciation and amortization (19,503 ) (14,500 ) Total property and equipment, net $ 22,157 $ 20,573

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Changes in Carrying Amount of Goodwill and Intangible Assets	The changes in the carrying amount of goodwill and intangible assets during 2020 and 2021 are as follows: Goodwill Intangible Assets Balance at December 31, 2019 $ 588 $ 353 Acquired during the period 15,620 5,520 Amortization - (183 ) Foreign currency exchange rate changes 18 4 Balance at December 31, 2020 16,226 5,694 Acquired during the period 1,302 - Change in value based on correction of purchase price calculation and allocation (2,222 ) (340 ) Amortization - (633 ) Impairment charge - (323 ) Foreign currency exchange rate changes (6 ) - Balance at December 31, 2021 $ 15,300 $ 4,398
Summary of Acquired Intangible Assets	The following table presents a summary of acquired intangible assets: As of December 31, 2021 Weighted Average Amortization Period in Years Gross Carrying Amount Accumulated Amortization Customer relationships 10.00 $ 2,420 $ (272 ) Developed technology 10.00 2,400 (271 ) Customer agreements 3.83 456 (335 ) Total intangible assets 9.47 $ 5,276 $ (878 )
Schedule of Estimated Amortization Expense for Intangible Assets	The estimated amortization expense for intangible assets for future years is as follows: 2022 $ 603 2023 482 2024 482 2025 482 2026 482 Thereafter 1,867 Total $ 4,398

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities and Other Long-Term Liabilities (Tables)	12 Months Ended
	Dec. 31, 2021
Payables And Accruals [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following: December 31, 2021 2020 Accrued bonuses $ 6,988 $ 6,584 Accrued commissions 5,181 11,689 Contingent consideration, current portion 3,952 5,322 Accrued payroll and employee-related costs 2,734 1,579 Operating lease liabilities, current portion 1,753 1,572 Accrued professional fees 1,682 1,156 Accrued taxes 1,450 1,717 Accrued inventory 1,111 1,423 Accrued vacation liability 786 793 Product warranty reserve 330 561 Other 2,592 1,637 Total accrued expenses and other current liabilities $ 28,559 $ 34,033
Schedule of Other Long-term Liabilities	Other long-term liabilities consist of the following: December 31, 2021 2020 Contingent consideration $ 5,164 $ 7,865 Operating lease liabilities 5,357 6,779 Deferred payroll taxes - 572 Other - 13 Total other long-term liabilities $ 10,521 $ 15,229

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Schedule of Annual Principal Maturities of Term Facility	The annual principal maturities of the Company’s CIBC Term Facility as of December 31, 2021 was as follows: Total Due Years Ended December 31, 2022 $ - 2023 3,200 2024 19,200 2025 17,600 Less: Unamortized deferred financing costs (274 ) Long-term loans payable $ 39,726

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Summary of Operating Lease Cost and Information Related to Operating Right of Use Assets and Operating Lease Liabilities	The following table presents operating lease cost and information related to operating right-of-use assets and operating lease liabilities: Year Ended December 31, 2021 2020 Lease cost: Operating lease cost $ 2,461 $ 1,717 Variable lease cost 475 379 Total $ 2,936 $ 2,096 Operating cash flow impacts: Cash paid for amounts included in measurement of lease liabilities $ 2,460 $ 1,731 Operating right of use assets obtained in exchange for new operating lease liabilities $ 549 $ 2,965 Weighted average remaining lease term - operating leases 3.3 years 4.2 years Weighted average discount rate - operating leases 8.1 % 8.0 %
Summary of Future Maturities of Lease Liabilities under Noncancelable Operating Leases	As of December 31, 2021, future maturities of lease liabilities under the Company’s noncancelable operating leases are as follows: Total Due Years Ended December 31, 2022 $ 2,255 2023 2,523 2024 2,562 2025 662 2026 113 Thereafter 5 Total payments 8,120 Less interest 1,010 Total present value of lease payments $ 7,110

Warrants (Tables)

Warrants (Tables)	12 Months Ended
	Dec. 31, 2021
Warrants And Rights Note Disclosure [Abstract]
Summary of Warrants Activity	The table below sets forth the Company’s warrant activity for the year ended December 31, 2020 and 2021: Number of Shares Weighted Average Exercise Price Outstanding at December 31, 2019 182,076 $ 14.84 Warrants granted - - Warrants exercised (148,128 ) 15.04 Outstanding at December 31, 2020 33,948 $ 14.00 Warrants granted - - Warrants exercised - - Outstanding at December 31, 2021 33,948 $ 14.00

Disaggregated Revenue (Tables)

Disaggregated Revenue (Tables)	12 Months Ended
	Dec. 31, 2021
Revenue From Contract With Customer [Abstract]
Net Revenue Disaggregated into Categories	The following table shows the Company’s net revenue disaggregated into categories the Company considers meaningful: For the Year Ended December 31, 2021 US International Total Net revenue by: Product Revenue Capital Equipment $ 22,549 $ 11,117 $ 33,666 Disposables 50,764 15,867 66,631 Subtotal Product Revenue 73,313 26,984 100,297 Lease Revenue Capital Equipment 4,087 234 $ 4,321 Other 1,691 418 $ 2,109 Service and Other Revenue 5,056 1,509 6,565 Net Revenue $ 84,147 $ 29,145 $ 113,292 For the Year Ended December 31, 2020 US International Total Net revenue by: Product Revenue Capital Equipment $ 45,464 $ 12,719 $ 58,183 Disposables 44,548 12,163 56,711 Subtotal Product Revenue 90,012 24,882 114,894 Lease Revenue Capital Equipment 5,698 72 $ 5,770 Other 1,659 352 $ 2,011 Service and Other Revenue 1,792 1,266 3,058 Net Revenue $ 99,161 $ 26,572 $ 125,733 For the Year Ended December 31, 2019 US International Total Net revenue by: Product Revenue Capital Equipment $ 6,144 $ 3,180 $ 9,324 Disposables 27,753 7,302 35,055 Subtotal Product Revenue 33,897 10,482 44,379 Lease Revenue 1,721 - 1,721 Service and Other Revenue 965 1,039 2,004 Net Revenue $ 36,583 $ 11,521 $ 48,104
Schedule of Changes in Contract Liabilities	The following table presents changes in contract liabilities during 2020 and 2021 Deferred Revenue Other Contract Liabilities Balance at December 31, 2019 $ 344 $ 137 Additions 3,137 459 Subtractions (963 ) (137 ) Balance at December 31, 2020 $ 2,518 $ 459 Additions 7,430 369 Subtractions (8,236 ) (459 ) Balance at December 31, 2021 $ 1,712 $ 369

Stock Plans and Stock-Based C_2

Stock Plans and Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2021
Summary of Allocated Stock Based Compensation Expense	Stock-based compensation expense was allocated based on the employees’ and non-employees’ functions as follows: Year Ended December 31, 2021 2020 2019 Cost of revenue $ 729 $ 351 $ 187 Research and development 1,187 843 405 Sales and marketing 3,171 2,115 782 General and administrative 4,679 3,121 2,462 Total $ 9,766 $ 6,430 $ 3,836
Summary of Stock Option Activity	Stock option activity for the year ended December 31, 2021 is as follows: Weighted Number of Weighted Average Underlying Average Remaining Aggregate Common Exercise Contractual Intrinsic Shares Price Term Value Outstanding at December 31, 2020 1,766,337 $ 12.15 8.32 $ 26,294 Options granted 466,390 26.30 Options exercised (168,289 ) 8.97 Options canceled (139,704 ) 17.68 Outstanding at December 31, 2021 1,924,734 $ 15.46 7.82 $ 13,071 Exercisable at December 31, 2021 900,763 $ 11.40 7.13 $ 8,606 Vested and unvested expected to vest at December 31, 2021 1,924,734 $ 15.46 7.82 $ 13,071
Schedule of Weighted Average Assumptions Used in Black-Scholes Options Pricing Model	The weighted average assumptions used in the Black-Scholes options pricing model are as follows: Year Ended December 31, 2021 2020 2019 Expected dividend yield 0.0 % 0.0 % 0.0 % Risk free interest rate 0.7 % 1.6 % 1.9 % Expected stock price volatility 86.6 % 87.6 % 64.5 % Expected term (years) 6.1 6.1 6.2
Schedule of Fair Value of ESPP Used in Black-Scholes Options Pricing Model	The fair value of the purchase right for the ESPP option is estimated on the date of grant using the Black-Scholes pricing model with the following assumptions: Year Ended December 31, 2021 2020 Expected dividend yield 0.0% 0.0% Risk free interest rate 0.2% 0.1% - 1.6% Expected stock price volatility 55.0% 93.0% - 131.0% Expected term (years) 0.5 0.4 - 0.5
Restricted Stock Units
Summary of Restricted Stock Units and Restricted Stock Awards	A summary of restricted stock unit activity for the year ended December 31, 2021 is as follows: Weighted Average Grant Date Shares Fair Value Unvested at December 31, 2020 228,489 $ 25.60 Granted 364,632 24.69 Vested (45,908 ) 28.96 Canceled (37,825 ) 25.03 Unvested at December 31, 2021 509,388 $ 24.69
Restricted Stock Awards
Summary of Restricted Stock Units and Restricted Stock Awards	A summary of restricted stock award activity for the year ended December 31, 2021 is as follows: Weighted Average Grant Date Shares Fair Value Unvested at December 31, 2020 103,650 $ 1.68 Granted/purchased - - Vested (95,661 ) 1.68 Canceled - - Unvested at December 31, 2021 7,989 $ 1.68

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Schedule of Net Loss Before Income Taxes	Net loss before income taxes is as follows: Year Ended December 31, 2021 2020 2019 United States $ (59,973 ) $ (51,591 ) $ (50,343 ) United Kingdom 73 89 (862 ) Germany 24 - - $ (59,876 ) $ (51,502 ) $ (51,205 )
Schedule of Reconciliation of Income Tax Expense	A reconciliation of income tax expense is computed as the statutory federal income tax rate to income taxes as reflected in the financial statement as follows: Year Ended December 31, 2021 2020 2019 Federal income tax benefit at statutory rate (21.0 %) (21.0 %) (21.0 %) Permanent differences (5.4 %) (5.9 %) (6.7 )% Change in valuation allowance 26.9 % 26.8 % 26.9 % Other (0.6 %) 0.1 % 0.5 % Income tax expense (0.1 %) 0.0 % (0.3 %)
Significant Components of Net Deferred Tax Assets	Significant components of the Company’s net deferred tax assets and liabilities are as follows: December 31, 2021 2020 Deferred Tax Assets Net operating loss carryforwards $ 69,579 $ 59,779 Deduction of research and development costs 9,945 8,356 Tax credit carryforwards 6,068 5,109 Accrued expenses 4,425 2,997 Operating lease liabilities 1,771 2,300 Stock option expense attributed to non-ISO stock 3,473 1,641 Accrued bonus and vacation 2,065 1,693 Inventory valuation reserves 117 136 Deferred revenue 281 - Accounts receivable allowance 105 100 Accrued warranty 89 151 Intangible assets 7 - Other temporary differences 684 561 Gross deferred tax assets 98,609 82,823 Less: Valuation allowance (95,309 ) (79,236 ) Deferred tax assets after valuation allowance 3,300 3,587 Deferred Tax Liabilities Depreciation (1,468 ) (1,220 ) Intangible assets - (28 ) Operating lease right of use assets (1,754 ) (2,300 ) Deferred revenue - (45 ) Gross deferred tax liabilities (3,222 ) (3,593 ) Net Deferred Tax Assets (Liabilities) $ 78 $ (6 )

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Schedule of Computation of Diluted Net Loss Per Share	The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect: Year Ended December 31, 2021 2020 2019 Options to purchase common stock 1,924,734 1,766,337 1,030,148 Unvested restricted stock units and awards 517,377 332,139 229,913 Employee stock purchase plan shares - 43,595 - Warrants to purchase common stock 33,948 33,948 182,076 2,476,059 2,176,019 1,442,137

Description of Business - Addit

Description of Business - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Dec. 20, 2019	May 31, 2020	Apr. 30, 2020	Aug. 31, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Entity founded year					1993
Entity reincorporated year					2013
Net proceeds from issuance of common stock						$ 94,155	$ 48,669
ATM Agreement
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Shares issued			511,648
Gross proceeds from issuance of common stock			$ 10,200
Net proceeds from issuance of common stock			$ 9,800
ATM Agreement | Jefferies LLC
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Gross proceeds from issuance of common stock	$ 50,000
Common Stock
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Shares issued		3,852,500		3,570,750		3,852,500	3,570,750
Exercise of underwriters option to purchase shares		502,500		465,750
Public offering price of common stock		$ 26		$ 14.50
Proceeds from initial offering net of underwriting discounts and offering costs		$ 93,800		$ 48,300
Underwriting discount		6,000		3,100
Offering expenses		$ 300		$ 400

Significant Accounting Polici_4

Significant Accounting Policies - Additional Information (Details)	3 Months Ended		12 Months Ended
	Dec. 31, 2021USD ($)	Mar. 31, 2021	Dec. 31, 2021USD ($)Segment	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of reporting segment | Segment			1
Number of reporting units | Segment			3
Maturity period of highly liquid investments with original maturities			90 days
Cash, cash equivalents and restricted cash balance	$ 57,324,000		$ 57,324,000	$ 115,536,000	$ 73,507,000	$ 60,022,000
Estimated useful life for certain of its demonstration, placement and evaluation units		5 years	7 years
Impairments of intangible assets	300,000		$ 323,000	0	0
Impairment of goodwill			$ 0	0	0
Standard product warranty period			1 year
Unamortized deferred financing costs, long-term	300,000		$ 300,000	300,000
Standard payment term to customer			30 days
Revenue, performance obligation, description of payment terms			When determining the transaction price of a contract, an adjustment is made if payment from a customer occurs either significantly before or significantly after performance, resulting in a significant financing component. Applying a practical expedient under ASC 606, the Company does not assess whether a significant financing component exists if the period between when the Company performs its obligations under the contract and when the customer pays is one year or less.
Revenue, remaining performance obligation, amount	0		$ 0	$ 0	$ 0
Vesting period			3 years
Dividend yield assumed			0.00%	0.00%	0.00%
Operating lease right-of-use assets	7,045,000		$ 7,045,000	$ 8,260,000
Lease liabilities	7,110,000		7,110,000
Deferred costs	0		0	0
Shipping and Handling
Summary Of Significant Accounting Policies [Line Items]
Shipping and handling costs			1,600,000	2,500,000	$ 1,000,000
Prepaid Expenses and Other Current Assets
Summary Of Significant Accounting Policies [Line Items]
Unamortized deferred financing costs, current	0		0
Current value of future lease payments	700,000		$ 700,000	2,700,000
Prepaid Expenses and Other Current Assets | Maximum
Summary Of Significant Accounting Policies [Line Items]
Unamortized deferred financing costs, current				100,000
Leasehold Improvements
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life for certain of its demonstration, placement and evaluation units			10 years
Impairment of property and equipment			$ 0	0	$ 0
Outside U.S.
Summary Of Significant Accounting Policies [Line Items]
Long-term assets	2,400,000		2,400,000	$ 200,000
Cash, cash equivalents and restricted cash balance	$ 1,100,000		$ 1,100,000

Significant Accounting Polici_5

Significant Accounting Policies - Components of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Cash and cash equivalents	$ 57,071	$ 113,683
Restricted cash	253	1,853
Total cash, cash equivalents, and restricted cash	$ 57,324	$ 115,536	$ 73,507	$ 60,022

Significant Accounting Polici_6

Significant Accounting Policies - Lives Used in Computing Straight-Line Depreciation (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Property and equipment placed in service, Number of years	5 years	7 years
Equipment | Maximum
Property Plant And Equipment [Line Items]
Property and equipment placed in service, Number of years		7 years
Equipment | Minimum [Member]
Property Plant And Equipment [Line Items]
Property and equipment placed in service, Number of years		3 years
Furniture | Maximum
Property Plant And Equipment [Line Items]
Property and equipment placed in service, Number of years		7 years
Furniture | Minimum [Member]
Property Plant And Equipment [Line Items]
Property and equipment placed in service, Number of years		5 years
Manufacturing Equipment | Maximum
Property Plant And Equipment [Line Items]
Property and equipment placed in service, Number of years		10 years
Manufacturing Equipment | Minimum [Member]
Property Plant And Equipment [Line Items]
Property and equipment placed in service, Number of years		3 years
Software | Maximum
Property Plant And Equipment [Line Items]
Property and equipment placed in service, Number of years		3 years
Software | Minimum [Member]
Property Plant And Equipment [Line Items]
Property and equipment placed in service, Number of years		2 years
Demonstration, Placements and Evaluation Units | Maximum
Property Plant And Equipment [Line Items]
Property and equipment placed in service, Number of years		7 years
Demonstration, Placements and Evaluation Units | Minimum [Member]
Property Plant And Equipment [Line Items]
Property and equipment placed in service, Number of years		3 years
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment placed in service, Number of years		10 years
Property and equipment placed in service, Term		Lesser of life of lease or 10 years

Significant Accounting Polici_7

Significant Accounting Policies - Summary of Roll-Forward Warranty Liability (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Balance, beginning of period	$ 561	$ 225
Provisions for warranty obligations	205	636
Settlements	(436)	(300)
Balance, end of period	$ 330	$ 561

Business Combinations - Additio

Business Combinations - Additional Information (Details) - USD ($)	Nov. 02, 2021	Nov. 13, 2020	Feb. 28, 2019	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Decrease in goodwill					$ 2,222,000
Decrease in intangible assets					340,000
Change in fair value of contingent consideration					$ (1,813,000)
Weighted average amortization period for intangible assets					9 years 5 months 19 days
PCI and RespirCare [Member]
Business Acquisition [Line Items]
Acquisition date	Nov. 2, 2021
Purchase price, net of cash acquired	$ 1,700,000
Initial cash payment	1,300,000
Settlement of preexisting transactions	400,000
Identified intangible assets	0
PCI and RespirCare [Member] | General and administrative
Business Acquisition [Line Items]
Transaction costs associated with acquisition	$ 500,000
HGE
Business Acquisition [Line Items]
Acquisition date		Nov. 13, 2020
Purchase price, net of cash acquired		$ 19,300,000
Initial cash payment		8,400,000
Change in fair value of contingent consideration		$ 10,900,000
Amortization period for intangible assets						10 years
HGE | Adjustment to Correct Immaterial Errors
Business Acquisition [Line Items]
Adjustment to correct immaterial errors, reduced the estimated purchase price				$ 2,300,000
Decrease in goodwill				2,200,000
Decrease in intangible assets				300,000
Decrease in other liabilities				$ 300,000
HGE | General and administrative
Business Acquisition [Line Items]
Transaction costs associated with acquisition						$ 200,000	$ 200,000
Solus
Business Acquisition [Line Items]
Acquisition date			Feb. 28, 2019
Purchase price, net of cash acquired			$ 2,000,000
Initial cash payment			1,600,000
Change in fair value of contingent consideration						$ 1,000,000	$ 1,000,000
Settlement of receivable from preexisting relationship			$ 400,000
Weighted average amortization period for intangible assets							3 years 9 months 29 days

Business Combinations - Summary

Business Combinations - Summary of Purchase Price Allocation (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Nov. 02, 2021	Dec. 31, 2020	Nov. 13, 2020	Dec. 31, 2019	Feb. 28, 2019
Business Acquisition [Line Items]
Goodwill	$ 15,300		$ 16,226		$ 588
PCI and RespirCare [Member]
Business Acquisition [Line Items]
Cash		$ 39
Accounts receivable		101
Prepaids and other current assets		11
Property and equipment		397
Operating lease right-of-use assets		316
Goodwill		1,302
Other long-term assets		9
Total assets acquired		2,175
Accounts payable		(29)
Other current liabilities		(111)
Other long-term liabilities		(264)
Total liabilities assumed		(404)
Total purchase price		$ 1,771
HGE
Business Acquisition [Line Items]
Cash				$ 2
Accounts receivable				518
Inventory				3
Prepaids and other current assets				238
Property and equipment				225
Operating lease right-of-use assets				2,329
Goodwill				13,398
Intangible assets				5,180
Other long-term assets				45
Total assets acquired				21,938
Accounts payable				(32)
Accrued expenses and other current liabilities				(620)
Contract liabilities				(31)
Other long-term liabilities				(1,951)
Total liabilities assumed				(2,634)
Total purchase price				$ 19,304
Solus
Business Acquisition [Line Items]
Cash						$ 466
Accounts receivable						411
Inventory						492
Prepaids and other current assets						3
Property and equipment						1
Goodwill						592
Intangible assets						455
Total assets acquired						2,420
Accounts payable						(241)
Contract liabilities						(75)
Deferred taxes						(78)
Total liabilities assumed						(394)
Total purchase price						$ 2,026

Business Combinations - Summa_2

Business Combinations - Summary of Changes to Contingent Consideration Payable (Details) - HGE - Fair Value, Inputs, Level 3 $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)
Business Acquisition Contingent Consideration [Line Items]
Balance at December 31, 2020	$ 13,187
Change in value of contingent consideration based on correction of purchase price calculation	(2,258)
Change in fair value of contingent consideration	(1,813)
Balance at December 31, 2021	$ 9,116

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($) $ in Thousands	Nov. 13, 2020	Dec. 31, 2021	Dec. 31, 2020	Mar. 22, 2019
Class Of Warrant Or Right [Line Items]
Contingent consideration as compensation expense		$ (1,813)
Amendment To Financing Arrangement | Common Stock Warrants
Class Of Warrant Or Right [Line Items]
Granted warrants to purchase shares				19,790
HGE
Class Of Warrant Or Right [Line Items]
Contingent consideration as compensation expense	$ 10,900
Level 1 | Money Market Deposits
Class Of Warrant Or Right [Line Items]
Cash equivalents		35,600	$ 90,300
Fair Value, Inputs, Level 3 | HGE
Class Of Warrant Or Right [Line Items]
Contingent consideration as compensation expense		$ 9,100	$ 13,200

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Assumptions Used in Black-Scholes Options Pricing Model at the Date of Grant (Details)	Dec. 31, 2021
Class Of Warrant Or Right [Line Items]
Expected term (years)	10 years
Expected Dividend Yield
Class Of Warrant Or Right [Line Items]
Key inputs used in valuation	0
Risk Free Interest Rate
Class Of Warrant Or Right [Line Items]
Key inputs used in valuation	0.024
Expected Stock Price Volatility
Class Of Warrant Or Right [Line Items]
Key inputs used in valuation	0.609

Accounts Receivable - Summary o

Accounts Receivable - Summary of Accounts Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accounts Notes And Loans Receivable [Line Items]
Total accounts receivable	$ 11,041	$ 23,860
Less: Allowance for doubtful accounts	(132)	(372)
Accounts receivable, net of allowance for doubtful accounts	10,909	23,488
United States
Accounts Notes And Loans Receivable [Line Items]
Total accounts receivable	8,894	18,893
International
Accounts Notes And Loans Receivable [Line Items]
Total accounts receivable	$ 2,147	$ 4,967

Accounts Receivable - Additiona

Accounts Receivable - Additional Information (Details) - Customer Concentration Risk - Customer	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Revenue
Accounts Notes And Loans Receivable [Line Items]
Number of customer accounted more than 10%	0	0
Accounts Receivable
Accounts Notes And Loans Receivable [Line Items]
Number of customer accounted more than 10%	0	0

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Inventory Disclosure [Abstract]
Component parts	$ 19,860	$ 10,367
Finished goods	16,702	9,506
Total inventory	$ 36,562	$ 19,873

Property and Equipment - Summar

Property and Equipment - Summary of Components of Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Total property and equipment	$ 41,660	$ 35,073
Less: Accumulated depreciation and amortization	(19,503)	(14,500)
Total property and equipment, net	22,157	20,573
Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	1,576	1,266
Furniture
Property Plant And Equipment [Line Items]
Total property and equipment	1,387	1,320
Manufacturing Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	14,318	10,658
Software
Property Plant And Equipment [Line Items]
Total property and equipment	1,306	845
Demonstration, Placements and Evaluation Units
Property Plant And Equipment [Line Items]
Total property and equipment	19,109	16,116
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment	2,977	2,482
Construction in Process
Property Plant And Equipment [Line Items]
Total property and equipment	$ 987	$ 2,386

Property and Equipment - Additi

Property and Equipment - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Depreciation of property and equipment	$ 5	$ 4.6	$ 3

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Schedule of Changes in Carrying Amount of Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Goodwill
Beginning Balance	$ 16,226	$ 588
Acquired during the period	1,302	15,620
Change in value based on correction of purchase price calculation and allocation	(2,222)
Foreign currency exchange rate changes	(6)	18
Ending Balance	15,300	16,226
Intangible Assets
Beginning Balance	5,694	353
Acquired during the period		5,520
Change in value based on correction of purchase price calculation and allocation	(340)
Amortization	(633)	(183)
Impairment charge	(323)
Foreign currency exchange rate changes		4
Ending Balance	$ 4,398	$ 5,694

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Summary of Acquired Intangible Assets (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)
Acquired Finite Lived Intangible Assets [Line Items]
Weighted Average Amortization Period	9 years 5 months 19 days
Gross Carrying Amount	$ 5,276
Accumulated Amortization	$ (878)
Customer Relationship
Acquired Finite Lived Intangible Assets [Line Items]
Weighted Average Amortization Period	10 years
Gross Carrying Amount	$ 2,420
Accumulated Amortization	$ (272)
Developed Technology
Acquired Finite Lived Intangible Assets [Line Items]
Weighted Average Amortization Period	10 years
Gross Carrying Amount	$ 2,400
Accumulated Amortization	$ (271)
Customer Agreements
Acquired Finite Lived Intangible Assets [Line Items]
Weighted Average Amortization Period	3 years 9 months 29 days
Gross Carrying Amount	$ 456
Accumulated Amortization	$ (335)

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Acquired Finite Lived Intangible Assets [Line Items]
Amortization expense of intangible assets	$ 633,000	$ 183,000
Sales and marketing
Acquired Finite Lived Intangible Assets [Line Items]
Amortization expense of intangible assets	400,000	100,000	$ 100,000
General and administrative
Acquired Finite Lived Intangible Assets [Line Items]
Amortization expense of intangible assets	$ 200,000		$ 0
General and administrative | Maximum
Acquired Finite Lived Intangible Assets [Line Items]
Amortization expense of intangible assets		$ 100,000

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Schedule of Estimated Amortization Expense for Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Finite Lived Intangible Assets Future Amortization Expense [Abstract]
2022	$ 603
2023	482
2024	482
2025	482
2026	482
Thereafter	1,867
Total	$ 4,398	$ 5,694	$ 353

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities and Other Long-Term Liabilities - Schedule of Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Payables And Accruals [Abstract]
Accrued bonuses	$ 6,988	$ 6,584
Accrued commissions	5,181	11,689
Contingent consideration, current portion	3,952	5,322
Accrued payroll and employee-related costs	2,734	1,579
Operating lease liabilities, current portion	$ 1,753	$ 1,572
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	us-gaap:OtherCurrentLiabilitiesMember	us-gaap:OtherCurrentLiabilitiesMember
Accrued professional fees	$ 1,682	$ 1,156
Accrued taxes	1,450	1,717
Accrued inventory	1,111	1,423
Accrued vacation liability	786	793
Product warranty reserve	330	561
Other	2,592	1,637
Total accrued expenses and other current liabilities	$ 28,559	$ 34,033

Accrued Expenses and Other Cu_4

Accrued Expenses and Other Current Liabilities and Other Long-Term Liabilities - Schedule of Other Long-term Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Payables And Accruals [Abstract]
Contingent consideration	$ 5,164	$ 7,865
Operating lease liabilities	$ 5,357	$ 6,779
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherNoncurrentLiabilitiesMember	us-gaap:OtherNoncurrentLiabilitiesMember
Deferred payroll taxes		$ 572
Other		13
Total other long-term liabilities	$ 10,521	$ 15,229

Debt - Additional Information (

Debt - Additional Information (Details) - USD ($)	Oct. 21, 2020	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Debt instrument, covenant description			The events of default under the Loan Agreement included, without limitation, and subject to customary grace periods, (1) the Company’s failure to make any payments of principal or interest under the Loan Agreement or other loan documents, (2) the Company’s breach or default in the performance of any covenant under the Loan Agreement, (3) the occurrence of a material adverse effect or an event that is reasonably likely to result in a material adverse effect, (4) the existence of an attachment or levy on a material portion of funds of the Company or its subsidiaries, (5) the Company’s insolvency or bankruptcy, or (6) the occurrence of certain material defaults with respect to any other of the Company’s indebtedness in excess of $500,000. If an event of default occurs, CIBC is entitled to take enforcement action, including acceleration of amounts due under the Loan Agreement.
Minimum amount of other indebtedness	$ 500,000
Loss on extinguishment of debt				$ 4,163,000
Canadian Imperial Bank of Commerce Innovation Banking
Debt Instrument [Line Items]
Loan agreement, payment terms			The CIBC Loan Agreement provided for interest-only payments on the CIBC Term Facility for the first 36 months through October 21, 2023. Thereafter, amortization payments on the CIBC Term Facility were to be payable monthly in 24 equal installments.
Line of credit facility, description			The CIBC Term Facility could not be prepaid prior to October 21, 2021 without prepaying all of the interest that otherwise would have been payable on the CIBC Term Facility during the period commencing on October 21, 2020 and ending on October 21, 2021, plus a prepayment charge of 2.0%. Thereafter, the CIBC Term Facility could be prepaid in full, subject to a prepayment charge of (i) 2.0%, if such prepayment occurred after October 21, 2021 but on or prior to October 21, 2022, and (ii) 1.0%, if such prepayment occurred after October 21, 2022 but on or prior to October 21, 2023.
Percentage of revenue covenant	80.00%
Canadian Imperial Bank of Commerce Innovation Banking | October 21, 2020 to October 21, 2021
Debt Instrument [Line Items]
Percentage of prepayment charge			2.00%
Canadian Imperial Bank of Commerce Innovation Banking | October 22, 2021 to October 21, 2022
Debt Instrument [Line Items]
Percentage of prepayment charge			2.00%
Canadian Imperial Bank of Commerce Innovation Banking | October 22, 2022 to October 21, 2023
Debt Instrument [Line Items]
Percentage of prepayment charge			1.00%
Canadian Imperial Bank of Commerce Innovation Banking | Revolving Credit Line
Debt Instrument [Line Items]
Outstanding balance under line of credit	$ 12,000,000		$ 6,600,000
Debt instrument, maturity date	Oct. 21, 2022
Debt instrument floor rate	3.25%
Line of credit, interest rate			4.25%
Additional borrowings			$ 0
Canadian Imperial Bank of Commerce Innovation Banking | Revolving Credit Line | Prime Rate
Debt Instrument [Line Items]
Debt instrument rate	1.00%
Canadian Imperial Bank of Commerce Innovation Banking | Term Facility
Debt Instrument [Line Items]
Outstanding balance under line of credit	$ 40,000,000		$ 40,000,000
Debt instrument, maturity date	Oct. 21, 2025
Debt instrument floor rate	3.25%
Line of credit, interest rate			5.75%
Canadian Imperial Bank of Commerce Innovation Banking | Term Facility | Prime Rate
Debt Instrument [Line Items]
Debt instrument rate	2.50%
Canadian Imperial Bank of Commerce Innovation Banking | Letters of credit
Debt Instrument [Line Items]
Outstanding balance under line of credit			$ 800,000
Perceptive Credit Holdings II, LP | Amended Revolver Agreement
Debt Instrument [Line Items]
Loss on extinguishment of debt		$ 4,200,000
Perceptive Credit Holdings II, LP | Amended Revolver Agreement | Cash
Debt Instrument [Line Items]
Amount to pay off all obligations owing and termination of agreements	$ 6,300,000
Perceptive Credit Holdings II, LP | Revolving Credit Line | Amended Revolver Agreement
Debt Instrument [Line Items]
Amount to pay off all obligations owing and termination of agreements	4,900,000
Perceptive Credit Holdings II, LP | Term Facility | Amended Revolver Agreement
Debt Instrument [Line Items]
Amount to pay off all obligations owing and termination of agreements	$ 40,000,000

Debt - Schedule of Annual Princ

Debt - Schedule of Annual Principal Maturities of Term Facility (Details) - Loans Payable - Canadian Imperial Bank of Commerce Innovation Banking $ in Thousands	Dec. 31, 2021USD ($)
Debt Instrument [Line Items]
2022	$ 0
2023	3,200
2024	19,200
2025	17,600
Less: Unamortized deferred financing costs	(274)
Long-term loans payable	$ 39,726

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Thousands	Dec. 16, 2019USD ($)	Nov. 30, 2021ft²Renewal	Nov. 30, 2020ft²Renewal	Oct. 31, 2019m²	Dec. 31, 2019USD ($)	Dec. 31, 2021USD ($)ft²Renewal	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Loss Contingencies [Line Items]
Rent expense								$ 2,000
Agreement to pay settlement	$ 650
Agreement settlement terms						The parties reached a settlement agreement on December 16, 2019 whereby the supplier agreed to pay the Company $0.65 million in a series of monthly payments through December 2021, and both the Company and the supplier agreed to release each from any other outstanding claims, which included $0.5 million of accounts payable the Company had previously recorded.
Gain on litigation settlement					$ 1,200		$ 15	$ 1,151
Non-cancellable purchase commitments						$ 3,700
Accounts Payable
Loss Contingencies [Line Items]
Outstanding claims for settlement	$ 500
100 Domain Drive, Exeter New Hampshire
Loss Contingencies [Line Items]
Area space under lease | ft²						95,320
Lease expiration						Jan. 28, 2025
Lease renewal term						5 years
Lease number of renewals | Renewal						2
2 Dryden Loan, Bilston Glen Industrial Estate, Loanhead in the United Kingdom
Loss Contingencies [Line Items]
Lease expiration				Feb. 15, 2027
Area of land | m²				453
1301 Virginia Drive, Fort Washington, Pennsylvania | Office Space
Loss Contingencies [Line Items]
Area space under lease | ft²			22,524
Lease expiration			Jul. 31, 2025
Lease renewal term			5 years
Lease number of renewals | Renewal			1
2832 and 2834 E. 101st Street, Tulsa, Oklahoma | Medical Space
Loss Contingencies [Line Items]
Area space under lease | ft²		4,790
Lease expiration		Jul. 31, 2026
Lease renewal term		5 years
Lease number of renewals | Renewal		2
Mesquite, Texas | Manufacturing and Warehouse Space
Loss Contingencies [Line Items]
Area space under lease | ft²		23,877
Lease expiration		Mar. 31, 2027
Lease renewal term		5 years
Lease expected commencement month and year		2022-02

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Operating Lease Cost and Information Related to Operating Right-of-Use Assets and Operating Lease Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Lease cost:
Operating lease cost	$ 2,461	$ 1,717
Variable lease cost	475	379
Total	2,936	2,096
Operating cash flow impacts:
Cash paid for amounts included in measurement of lease liabilities	2,460	1,731
Operating right of use assets obtained in exchange for new operating lease liabilities	$ 549	$ 2,965
Weighted average remaining lease term - operating leases	3 years 3 months 18 days	4 years 2 months 12 days
Weighted average discount rate - operating leases	8.10%	8.00%

Commitments and Contingencies_3

Commitments and Contingencies - Summary of Future Maturities of Lease Liabilities under Noncancelable Operating Leases (Details) $ in Thousands	Dec. 31, 2021USD ($)
Commitments And Contingencies Disclosure [Abstract]
2022	$ 2,255
2023	2,523
2024	2,562
2025	662
2026	113
Thereafter	5
Total payments	8,120
Less interest	1,010
Lease liabilities	$ 7,110
Operating Lease, Liability, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilities

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details)	12 Months Ended
	Dec. 31, 2021Vote$ / sharesshares	Dec. 31, 2020$ / sharesshares
Equity [Abstract]
Preferred stock, shares authorized	25,000,000	25,000,000
Preferred stock, par value | $ / shares	$ 0.001	$ 0.001
Preferred stock, shares outstanding	0	0
Common stock, shares authorized	175,000,000	175,000,000
Common stock, shares issued	26,126,253	25,722,984
Common stock, shares outstanding	26,126,253	25,722,984
Common stock, par value | $ / shares	$ 0.001	$ 0.001
Common stock voting rights	Each share of common stock is entitled to one vote.
Number of vote each share of common stock entitled | Vote	1

Warrants - Additional Informati

Warrants - Additional Information (Details) - Common Stock Warrants - $ / shares	Oct. 01, 2020	Aug. 07, 2020	Jul. 10, 2020	Jun. 10, 2020	Dec. 31, 2021	Dec. 31, 2020
Class Of Warrant Or Right [Line Items]
Warrants to purchase of common stock shares, net exercised	42,857	4,285	20,889	80,097	0	148,128
Warrants exercise price	$ 14	$ 14	$ 14	$ 15.92
Number of warrants withhold upon warrants exercise	20,689	2,064	6,902	39,031
Issuance of common stock upon exercise of warrants, shares	22,168	2,221	13,987	41,066
Minimum
Class Of Warrant Or Right [Line Items]
Warrants expire date					2022-03
Maximum
Class Of Warrant Or Right [Line Items]
Warrants expire date					2025-07
Periods Ranging from March 14, 2022 to July 28, 2025
Class Of Warrant Or Right [Line Items]
Warrants exercise price					$ 14

Warrants - Summary of Warrants

Warrants - Summary of Warrants Activity (Details) - Common Stock Warrants - $ / shares	Oct. 01, 2020	Aug. 07, 2020	Jul. 10, 2020	Jun. 10, 2020	Dec. 31, 2021	Dec. 31, 2020
Class Of Warrant Or Right [Line Items]
Number of shares, beginning balance					33,948	182,076
Number of shares, warrants granted					0	0
Number of shares, warrants exercised	(42,857)	(4,285)	(20,889)	(80,097)	0	(148,128)
Number of shares, ending balance					33,948	33,948
Weighted average exercise price, ending balance	$ 14	$ 14	$ 14	$ 15.92
Weighted Average
Class Of Warrant Or Right [Line Items]
Weighted average exercise price, beginning balance					$ 14	$ 14.84
Weighted average exercise price, warrants granted					0	0
Weighted average exercise price, warrants exercised					0	15.04
Weighted average exercise price, ending balance					$ 14	$ 14

Disaggregated Revenue - Net Rev

Disaggregated Revenue - Net Revenue Disaggregated into Categories (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation Of Revenue [Line Items]
Net Revenue	$ 113,292	$ 125,733	$ 48,104
US
Disaggregation Of Revenue [Line Items]
Net Revenue	84,147	99,161	36,583
International
Disaggregation Of Revenue [Line Items]
Net Revenue	29,145	26,572	11,521
Capital Equipment Product Revenue
Disaggregation Of Revenue [Line Items]
Net Revenue	33,666	58,183	9,324
Capital Equipment Product Revenue | US
Disaggregation Of Revenue [Line Items]
Net Revenue	22,549	45,464	6,144
Capital Equipment Product Revenue | International
Disaggregation Of Revenue [Line Items]
Net Revenue	11,117	12,719	3,180
Disposables Product Revenue
Disaggregation Of Revenue [Line Items]
Net Revenue	66,631	56,711	35,055
Disposables Product Revenue | US
Disaggregation Of Revenue [Line Items]
Net Revenue	50,764	44,548	27,753
Disposables Product Revenue | International
Disaggregation Of Revenue [Line Items]
Net Revenue	15,867	12,163	7,302
Product Revenue
Disaggregation Of Revenue [Line Items]
Net Revenue	100,297	114,894	44,379
Product Revenue | US
Disaggregation Of Revenue [Line Items]
Net Revenue	73,313	90,012	33,897
Product Revenue | International
Disaggregation Of Revenue [Line Items]
Net Revenue	26,984	24,882	10,482
Lease Revenue
Disaggregation Of Revenue [Line Items]
Net Revenue			1,721
Lease Revenue | US
Disaggregation Of Revenue [Line Items]
Net Revenue			1,721
Lease Revenue, Capital Equipment
Disaggregation Of Revenue [Line Items]
Net Revenue	4,321	5,770
Lease Revenue, Capital Equipment | US
Disaggregation Of Revenue [Line Items]
Net Revenue	4,087	5,698
Lease Revenue, Capital Equipment | International
Disaggregation Of Revenue [Line Items]
Net Revenue	234	72
Service, Other
Disaggregation Of Revenue [Line Items]
Net Revenue	6,565	3,058	2,004
Service, Other | US
Disaggregation Of Revenue [Line Items]
Net Revenue	5,056	1,792	965
Service, Other | International
Disaggregation Of Revenue [Line Items]
Net Revenue	1,509	1,266	$ 1,039
Lease Revenue, Other
Disaggregation Of Revenue [Line Items]
Net Revenue	2,109	2,011
Lease Revenue, Other | US
Disaggregation Of Revenue [Line Items]
Net Revenue	1,691	1,659
Lease Revenue, Other | International
Disaggregation Of Revenue [Line Items]
Net Revenue	$ 418	$ 352

Disaggregated Revenue - Schedul

Disaggregated Revenue - Schedule of Changes in Contract Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Contract Liabilities
Balance at December 31, 2019	$ 459	$ 137
Additions	369	459
Subtractions	(459)	(137)
Balance at December 31, 2020	369	459
Deferred Revenue
Balance at December 31, 2019	2,518	344
Additions	7,430	3,137
Subtractions	(8,236)	(963)
Balance at December 31, 2020	$ 1,712	$ 2,518

Stock Plans and Stock-Based C_3

Stock Plans and Stock-Based Compensation - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		12 Months Ended
	Nov. 30, 2018	Dec. 31, 2021	Mar. 31, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2016	May 31, 2020	Aug. 31, 2019	Oct. 30, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved and available for future issuance maximum cumulative increase percentage on immediate preceding year end common stock issued and outstanding										4.00%
Additional compensation expense		$ 100,000		$ 9,766,000	$ 6,430,000	$ 3,836,000
Vesting period				3 years
Weighted average grant date fair value of options granted				$ 18.97	$ 9.90	$ 9.20
Aggregate intrinsic value of options exercised				$ 3,300,000	$ 6,800,000	$ 2,300,000
Unrecognized stock-based compensation expense		$ 10,200,000		$ 10,200,000
Unrecognized stock-based compensation expense recognized, remaining weighted average vesting period				2 years 8 months 12 days
Issuance of common stock upon exercise of options, shares				168,289
Average forfeiture rate				4.17%	4.17%	6.73%
Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved and available for future issuance maximum cumulative increase percentage on immediate preceding year end common stock issued and outstanding										1.00%
Common stock reserved and available for issuance cumulatively increase description				The number of shares of common stock available for issuance under the ESPP is increased on the first day of each calendar year beginning January 1, 2019 and each year thereafter until 2028 by the lesser of (i) 1% of the number of shares of common stock issued and outstanding on the immediately preceding December 31, or (ii) the number of shares of common stock determined by the Board of Directors up to such an initial maximum of 1,741,300 shares of common stock. The number of shares of common stock reserved under the plan at December 31, 2021 totals 673,258.
Common stock reserved for issuance		673,258		673,258						166,500
Initial maximum number of common stock determined by board of directors										1,741,300
Cash proceeds from issuance of common stock				$ 1,139,000	$ 824,000
Maximum percentage to purchase shares of eligible compensation a participant receives during each offering period	10.00%
Maximum amount of shares a participant can accrue at discounted rate of the fair market value.	$ 25,000
Maximum number of shares per participant	5,000
Purchase price as a percentage of its market price on first trading day of each offering period	85.00%
Nonrecourse Notes
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock upon exercise of options, shares				0	0	0	79,865
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period			36 months
Number of shares granted			68,526
Award vesting percentage			25.00%
Restricted Stock Units and Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation expense recognized, remaining weighted average vesting period				2 years 2 months 12 days
Unrecognized stock-based compensation expense		$ 8,600,000		$ 8,600,000
Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock upon exercise of options, shares				168,289	223,998	150,176
Common stock shares issued				75,313	58,140
Common stock price per share								$ 26	$ 14.50
Common Stock | Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares issued				75,313	58,140
Common stock price per share		$ 15.12		$ 15.12	$ 14.19
2018 Equity Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock remain available for issuance										998,900
Common stock reserved and available for issuance cumulatively increase description				the number of shares of common stock available for issuance under the 2018 Equity Plan is increased on the first day of each calendar year beginning January 1, 2019 and each year thereafter until 2028 by the lesser of (i) four percent of the number of outstanding shares of common stock as of the close of business on the immediately preceding December 31 or (ii) the number of shares determined by the Board of Directors on or prior to such date.
Common stock reserved for issuance		1,239,402		1,239,402
2018 Equity Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period				1 year
2018 Equity Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period				4 years
Options exercisable, period				10 years
2018 Equity Plan | Common Stock | Board of Directors and Consultants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, granted				18,098	19,387	17,644
2015 Equity Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock remain available for issuance										769,419

Stock Plans and Stock-Based C_4

Stock Plans and Stock-Based Compensation - Summary of Allocated Stock Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Allocated stock based compensation expense	$ 100	$ 9,766	$ 6,430	$ 3,836
Cost of revenue
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Allocated stock based compensation expense		729	351	187
Research and development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Allocated stock based compensation expense		1,187	843	405
Sales and marketing
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Allocated stock based compensation expense		3,171	2,115	782
General and administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Allocated stock based compensation expense		$ 4,679	$ 3,121	$ 2,462

Stock Plans and Stock-Based C_5

Stock Plans and Stock-Based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Underlying Common Shares, Outstanding, Beginning balance	1,766,337
Number of Underlying Common Shares, Options granted	466,390
Number of Underlying Common Shares, Options exercised	(168,289)
Number of Underlying Common Shares, Options canceled	(139,704)
Number of Underlying Common Shares, Outstanding, Ending balance	1,924,734	1,766,337
Number of Underlying Common Shares, Exercisable	900,763
Number of Underlying Common Shares, Vested and unvested expected to vest	1,924,734
Weighted Average Exercise Price, Outstanding, Beginning balance	$ 12.15
Weighted Average Exercise Price, Options granted	26.30
Weighted Average Exercise Price, Options exercised	8.97
Weighted Average Exercise Price, Options canceled	17.68
Weighted Average Exercise Price, Outstanding, Ending balance	15.46	$ 12.15
Weighted Average Exercise Price, Exercisable	11.40
Weighted Average Exercise Price, Vested and unvested expected to vest	$ 15.46
Weighted Average Remaining Contractual Term	7 years 9 months 25 days	8 years 3 months 25 days
Weighted Average Remaining Contractual Term, Exercisable	7 years 1 month 17 days
Weighted Average Remaining Contractual Term, Vested and unvested expected to vest	7 years 9 months 25 days
Aggregate Intrinsic Value, Outstanding	$ 13,071	$ 26,294
Aggregate Intrinsic Value, Exercisable	8,606
Aggregate Intrinsic Value, Vested and unvested expected to vest	$ 13,071

Stock Plans and Stock-Based C_6

Stock Plans and Stock-Based Compensation - Schedule of Weighted Average Assumptions Used in Black-Scholes Options Pricing Model (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Expected dividend yield	0.00%	0.00%	0.00%
Risk free interest rate	0.70%	1.60%	1.90%
Expected stock price volatility	86.60%	87.60%	64.50%
Expected term (years)	6 years 1 month 6 days	6 years 1 month 6 days	6 years 2 months 12 days

Stock Plans and Stock-Based C_7

Stock Plans and Stock-Based Compensation - Summary of Restricted Stock Units and Restricted Stock Awards (Details) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2021
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares, Unvested, Beginning balance		228,489
Shares, Granted		364,632
Shares, Vested		(45,908)
Shares, Canceled		(37,825)
Shares, Unvested Ending balance		509,388
Weighted Average Grant Date Fair Value, Unvested, Beginning balance		$ 25.60
Weighted Average Grant Date Fair Value, Granted		24.69
Weighted Average Grant Date Fair Value, Vested		28.96
Weighted Average Grant Date Fair Value, Canceled		25.03
Weighted Average Grant Date Fair Value, Unvested Ending balance		$ 24.69
Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares, Unvested, Beginning balance		103,650
Shares, Granted	68,526
Shares, Vested		(95,661)
Shares, Unvested Ending balance		7,989
Weighted Average Grant Date Fair Value, Unvested, Beginning balance		$ 1.68
Weighted Average Grant Date Fair Value, Vested		1.68
Weighted Average Grant Date Fair Value, Unvested Ending balance		$ 1.68

Stock Plans and Stock-Based C_8

Stock Plans and Stock-Based Compensation - Schedule of Fair Value of ESPP Used in Black-Scholes Options Pricing Model (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield	0.00%	0.00%	0.00%
Risk free interest rate	0.70%	1.60%	1.90%
Expected stock price volatility	86.60%	87.60%	64.50%
Expected term (years)	6 years 1 month 6 days	6 years 1 month 6 days	6 years 2 months 12 days
Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield	0.00%	0.00%
Risk free interest rate	0.20%
Risk free interest rate, minimum		0.10%
Risk free interest rate, maximum		1.60%
Expected stock price volatility	55.00%
Expected stock price volatility, minimum		93.00%
Expected stock price volatility, maximum		131.00%
Expected term (years)	6 months
Employee Stock Purchase Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)		4 months 24 days
Employee Stock Purchase Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)		6 months

Income Taxes - Schedule of Net

Income Taxes - Schedule of Net Loss Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Contingency [Line Items]
United States	$ (59,973)	$ (51,591)	$ (50,343)
Net loss before income taxes	(59,876)	(51,502)	(51,205)
United Kingdom
Income Tax Contingency [Line Items]
Net loss before income taxes	73	$ 89	$ (862)
Germany
Income Tax Contingency [Line Items]
Net loss before income taxes	$ 24

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Contingency [Line Items]
Income tax benefit, related to foreign net deferred income tax assets	$ 100,000		$ 100,000
Income tax provision, United States	0	$ 0	0
Provision or (benefit) for income taxes	(76,000)	0	$ (146,000)
Valuation allowance	95,309,000	79,236,000
Increase in valuation allowance	$ 16,100,000
Income tax examination, description	Years beginning in 2018 remain open to examination for both federal and state purposes.
Liabilities associated with uncertain tax positions	$ 0	0
Uncertain tax positions, interest and penalties	0	$ 0
Federal
Income Tax Contingency [Line Items]
Net operating loss carryforwards	$ 293,300,000
Net operating loss carryforwards, expiration beginning year	2022
Federal | Research and Development
Income Tax Contingency [Line Items]
Tax credit carryforward	$ 5,900,000
Tax credit carryforward, expiration beginning year	2022
State
Income Tax Contingency [Line Items]
Net operating loss carryforwards	$ 137,500,000
Net operating loss carryforwards, expiration beginning year	2022

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Income Tax Expense (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Federal income tax benefit at statutory rate	(21.00%)	(21.00%)	(21.00%)
Permanent differences	(5.40%)	(5.90%)	(6.70%)
Change in valuation allowance	26.90%	26.80%	26.90%
Other	(0.60%)	0.10%	0.50%
Income tax expense	(0.10%)	(0.00%)	(0.30%)

Income Taxes - Significant Comp

Income Taxes - Significant Components of Net Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred Tax Assets
Net operating loss carryforwards	$ 69,579	$ 59,779
Deduction of research and development costs	9,945	8,356
Tax credit carryforwards	6,068	5,109
Accrued expenses	4,425	2,997
Operating lease liabilities	1,771	2,300
Stock option expense attributed to non-ISO stock	3,473	1,641
Accrued bonus and vacation	2,065	1,693
Inventory valuation reserves	117	136
Deferred revenue	281
Accounts receivable allowance	105	100
Accrued warranty	89	151
Intangible assets	7
Other temporary differences	684	561
Gross deferred tax assets	98,609	82,823
Less: Valuation allowance	(95,309)	(79,236)
Deferred tax assets after valuation allowance	3,300	3,587
Deferred Tax Liabilities
Depreciation	(1,468)	(1,220)
Intangible assets		(28)
Operating lease right of use assets	(1,754)	(2,300)
Deferred revenue		(45)
Gross deferred tax liabilities	(3,222)	(3,593)
Net Deferred Tax Assets (Liabilities)	$ 78
Net Deferred Tax Assets (Liabilities)		$ (6)

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Computation of Diluted Net Loss Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	2,476,059	2,176,019	1,442,137
Employee Stock Purchase Plan Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		43,595
Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,924,734	1,766,337	1,030,148
Unvested Restricted Stock Units and Awards
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	517,377	332,139	229,913
Warrants to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	33,948	33,948	182,076

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details)	12 Months Ended
	Dec. 31, 2021USD ($)
Related Party Transaction [Line Items]
Sales to related party	$ 1,200,000
Outstanding balances due from related party	$ 0
Minimum
Related Party Transaction [Line Items]
Percentage of common stock held by holder	5.00%

Employee Benefit Plan - Additio

Employee Benefit Plan - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Maximum annual contributions per employee	100.00%
Employer matching contribution percentage	100.00%		50.00%
Maximum employer contribution amount of employee compensation	6.00%		4.00%
Annual contributions per employee	$ 2,000	$ 1,000
Defined contribution plan	$ 600,000	$ 300,000	$ 100,000
For Employee with Annual Earnings Less Than $50,000
Defined Benefit Plan Disclosure [Line Items]
Annual contributions per employee			1,000
For Employee with Annual Earnings Greater Than $50,000
Defined Benefit Plan Disclosure [Line Items]
Annual contributions per employee			500
Maximum
Defined Benefit Plan Disclosure [Line Items]
Employees annual earnings			50,000
Minimum
Defined Benefit Plan Disclosure [Line Items]
Employees annual earnings			$ 50,000

Subsequent Event - Additional I

Subsequent Event - Additional Information (Details) - USD ($)	Feb. 18, 2022	Dec. 31, 2021	Oct. 21, 2020
Subsequent Event [Line Items]
Debt instrument, covenant description		The events of default under the Loan Agreement included, without limitation, and subject to customary grace periods, (1) the Company’s failure to make any payments of principal or interest under the Loan Agreement or other loan documents, (2) the Company’s breach or default in the performance of any covenant under the Loan Agreement, (3) the occurrence of a material adverse effect or an event that is reasonably likely to result in a material adverse effect, (4) the existence of an attachment or levy on a material portion of funds of the Company or its subsidiaries, (5) the Company’s insolvency or bankruptcy, or (6) the occurrence of certain material defaults with respect to any other of the Company’s indebtedness in excess of $500,000. If an event of default occurs, CIBC is entitled to take enforcement action, including acceleration of amounts due under the Loan Agreement.
Minimum amount of other indebtedness			$ 500,000
SLR Investment Corporation (“SLR”)
Subsequent Event [Line Items]
Debt instrument, covenant description		The events of default under the Loan Agreement include, without limitation, and subject to customary grace periods, (1) the Company’s failure to make any payments of principal or interest under the Loan Agreement or other loan documents, (2) the Company’s breach or default in the performance of any covenant under the Loan Agreement, (3) the occurrence of a material adverse effect or an event that is reasonably likely to result in a material adverse effect, (4) the existence of an attachment or levy on a material portion of the Company’s funds or of its subsidiaries, (5) the Company’s insolvency or bankruptcy, or (6) the occurrence of certain material defaults with respect to any other of the Company’s indebtedness in excess of $500,000. If an event of default occurs, SLR is entitled to take enforcement action, including acceleration of amounts due under the Loan Agreement.
Facilities | SLR Investment Corporation (“SLR”)
Subsequent Event [Line Items]
Loan agreement, payment terms		The Loan Agreement provides for interest-only payments for the first forty-eight months following the Effective Date. Thereafter, amortization payments on the Facilities will be payable monthly in twenty-four equal installments; provided that the Company shall have the option to extend the interest-only period for an additional twelve months upon achievement of a certain minimum revenue level as more fully described in the Loan Agreement.
Subsequent Events | SLR Investment Corporation (“SLR”)
Subsequent Event [Line Items]
Percentage of revenue covenant	75.00%
Minimum amount of other indebtedness	$ 500,000
Subsequent Events | Term Loan A Facility | SLR Investment Corporation (“SLR”)
Subsequent Event [Line Items]
Outstanding balance under line of credit	100,000,000
Amount utilized to terminate CBIC Facilities	47,400,000
Subsequent Events | Term Loan B Facility | SLR Investment Corporation (“SLR”)
Subsequent Event [Line Items]
Outstanding balance under line of credit	$ 25,000,000
Subsequent Events | Facilities | SLR Investment Corporation (“SLR”)
Subsequent Event [Line Items]
Debt instrument, maturity date	Feb. 1, 2027
Line of credit, interest rate	0.10%
Subsequent Events | Facilities | SLR Investment Corporation (“SLR”) | LIBOR Rate
Subsequent Event [Line Items]
Debt instrument rate	8.30%