Pulse Biosciences (PLSE) 10-Q 11 May 23 2023 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2023	Apr. 30, 2023
Document Information [Line Items]
Entity Central Index Key	0001625101
Entity Registrant Name	Pulse Biosciences, Inc.
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2023
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
Document Transition Report	false
Entity File Number	001-34899
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-5696597
Entity Address, Address Line One	3957 Point Eden Way
Entity Address, City or Town	Hayward
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94545
City Area Code	510
Local Phone Number	906-4600
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	PLSE
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		37,641,892

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 54,098	$ 61,139
Prepaid expenses and other current assets	849	1,008
Total current assets	54,947	62,147
Property and equipment, net	1,865	1,961
Intangible assets, net	2,384	2,551
Goodwill	2,791	2,791
Right-of-use assets	7,869	8,062
Other assets	365	365
Total assets	70,221	77,877
Current liabilities:
Accounts payable	2,160	1,573
Accrued expenses	3,091	2,595
Deferred revenue	4	0
Lease liability, current	935	896
Related party note payable, current	801	917
Total current liabilities	6,991	5,981
Lease liability, less current portion	8,898	9,144
Related party note payable, less current	65,000	65,000
Total liabilities	80,889	80,125
Commitments and contingencies (Note 13)
Stockholders’ equity:
Preferred stock, $0.001 par value; authorized – 50,000 shares; no shares issued and outstanding	0	0
Common stock, $0.001 par value; authorized – 500,000 shares; issued and outstanding – 37,593 shares and 37,235 shares at March 31, 2023 and December 31, 2022, respectively	37	37
Additional paid-in capital	293,801	292,420
Accumulated other comprehensive income (loss)	0	0
Accumulated deficit	(304,506)	(294,705)
Total stockholders’ deficit	(10,668)	(2,248)
Total liabilities and stockholders’ equity	$ 70,221	$ 77,877

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares shares in Thousands	Mar. 31, 2023	Dec. 31, 2022
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	50,000	50,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	500,000	500,000
Common stock, shares issued (in shares)	37,593	37,235
Common stock, shares outstanding (in shares)	37,593	37,235

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenues:
Total revenues	$ 0	$ 444
Cost and expenses:
Cost of revenues	0	909
Research and development	5,829	6,769
Sales and marketing	0	5,541
General and administrative	3,733	4,498
Total cost and expenses	9,562	17,717
Loss from operations	(9,562)	(17,273)
Other income (expense):
Interest income (expense), net	(239)	0
Total other income (expense)	(239)	0
Loss from operations, before income taxes	(9,801)	(17,273)
Income tax benefit	0	0
Net loss	(9,801)	(17,273)
Other comprehensive gain (loss):
Unrealized gain (loss) on available-for-sale securities	0	0
Comprehensive loss	$ (9,801)	$ (17,273)
Net loss per share:
Basic and diluted net loss per share (in dollars per share)	$ (0.26)	$ (0.58)
Weighted average shares used to compute net loss per common share — basic and diluted (in shares)	37,390	29,745
Product [Member]
Revenues:
Total revenues	$ 0	$ 444

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities:
Net loss	$ (9,801)	$ (17,273)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	135	160
Amortization of intangible assets	167	166
Stock-based compensation	896	2,007
Changes in operating assets and liabilities:
Accounts receivable	0	40
Inventory	0	(1,663)
Prepaid expenses and other current assets	160	191
Other receivables	(1)	(39)
Right-of-use assets	193	174
Accounts payable	587	609
Accrued expenses	496	215
Deferred revenue	4	0
Lease liabilities	(207)	(182)
Accrued interest on related party note payable	801	0
Accrued interest on note payable	0	1
Net cash used in operating activities	(6,570)	(15,594)
Cash flows from investing activities:
Purchases of property and equipment	(39)	(279)
Net cash used in investing activities	(39)	(279)
Cash flows from financing activities:
Proceeds from issuance of common stock under employee stock purchase plan	291	372
Proceeds from exercises of warrants	194	0
Payments made on insurance loan agreement	0	(437)
Payments made on related party note	(917)	0
Net cash used in financing activities	(432)	(65)
Net decrease in cash and cash equivalents	(7,041)	(15,938)
Cash and cash equivalents at beginning of period	61,139	28,614
Cash and cash equivalents at end of period	54,098	12,676
Supplemental disclosure of noncash investing and financing activities:
Equipment purchases included in accounts payable and accrued expenses	$ 0	$ (27)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Dec. 31, 2021	29,716
Balance at Dec. 31, 2021	$ 29	$ 271,861	$ 0	$ (236,200)	$ 35,690
Issuance of shares under employee stock purchase plan (in shares)	86
Issuance of shares under employee stock purchase plan	$ 0	372	0	0	372
Stock-based compensation expense	0	2,007	0	0	2,007
Net loss	$ 0		0	(17,273)	(17,273)
Balance (in shares) at Mar. 31, 2022	29,802
Balance at Mar. 31, 2022	$ 29	274,240	0	(253,473)	20,796
Balance (in shares) at Dec. 31, 2022	37,235
Balance at Dec. 31, 2022	$ 37	292,420	0	(294,705)	(2,248)
Issuance of shares under employee stock purchase plan (in shares)	262
Issuance of shares under employee stock purchase plan	$ 0	291	0	0	291
Issuance of shares upon exercise of warrants (in shares)	96
Issuance of shares upon exercise of warrants	$ 0	194	0	0	194
Stock-based compensation expense	0	896	0	0	896
Net loss	$ 0	0	0	(9,801)	(9,801)
Balance (in shares) at Mar. 31, 2023	37,593
Balance at Mar. 31, 2023	$ 37	$ 293,801	$ 0	$ (304,506)	$ (10,668)

Note 1 - Description of Busines

Note 1 - Description of Business	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	1. Pulse Biosciences, Inc. is a novel bioelectric medicine company committed to health innovation using its patented Nano-pulse Stimulation (“NPS”) technology, a revolutionary energy modality that delivers nanosecond-duration pulses of electrical energy, each less than a millionth of a second 2022 The Company was incorporated in Nevada on May 19, 2014. June 18, 2018, The Company’s activities are subject to significant risks and uncertainties, including the need for additional capital. The Company does not no

Note 2 - Summary of Significant

Note 2 - Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Significant Accounting Policies [Text Block]	2. Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared on a basis consistent with the Company’s December 31, 2022 December 31, 2022 not 10 December 31, 2022 three March 31, 2023, not Principles of Consolidation The accompanying condensed consolidated financial statements include the financial statements of Pulse Biosciences, Inc. and its wholly-owned subsidiaries. Intercompany balances and transactions, if any, have been eliminated in consolidation. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires the Company to make estimates and assumptions that affect the amounts reported in the Financial Statements and accompanying notes to the condensed consolidated financial statements. Estimates include, but are not Significant Accounting Policies The Company’s significant accounting policies are described in the Company’s Annual Report on Form 10 December 31, 2022 no three March 31, 2023 10 December 31, 2022 Valuation of Inventory Inventory is stated at lower of cost or net realizable value. The Company establishes the inventory basis by determining the cost based on standard costs approximating the purchase costs on a first first December 31, 2022, not Revenue from Contracts with Customers The Company recognized revenue at a point in time when it satisfied performance obligations by transferring control of promised goods to its customers. The amount of revenue recognized was equal to the consideration which the Company was entitled to in exchange for the promised goods, excluding any amounts assessed by government authorities for taxes which might have been collected from a customer. Sales contracts often involved the sale and delivery of multiple products, each of which typically represented a separate performance obligation in the contract. While the Company has sold these products on a stand-alone basis at their respective stand-alone selling prices (“SSP”), initial customer contracts primarily involved the bundling of products which were delivered concurrently to the customer. In such instances, the full consideration of the contract was recognized upon shipment of the products. The Company generally required receipt of full payment prior to shipment, however, from time to time, payment terms were extended to customers upon which the Company performed a necessary credit evaluation to ensure future collectability of the outstanding balance. The accounts receivable balance at March 31, 2023 zero not 10 Product Warranty The Company provides a standard warranty on eligible products which provides the customer assurances that the products comply with the agreed-upon specifications. The standard warranty does not may Warranty accrual activity consisted of the following for the three March 31, 2023 2022 Three Months Ended March 31, 2023 2022 Beginning balance $ 50 $ 80 Add: Accruals for warranties issued during the period — 17 Less: Adjustment for inventory at cost and excessive and obsolete inventory — — Ending balance $ 50 $ 97 Net Loss per Share The Company calculates basic net loss per share by dividing net loss by the weighted-average number of shares of common stock outstanding during the period. Diluted net loss per share is computed by giving effect to all potential dilutive common stock equivalents outstanding during the period. For purposes of this calculation, options to purchase common stock and common stock warrants are considered common stock equivalents. Potential common shares that have an anti-dilutive effect (i.e., those that increase income per share or decrease loss per share) are excluded from the calculation of diluted net loss per share. Basic and diluted net loss per common share is the same for all periods presented because all warrants, stock options and restricted stock units outstanding are anti-dilutive. The following outstanding stock options, and warrants were excluded from the computation of diluted net loss per share for the periods presented because including them would have had an anti-dilutive effect: Three Months Ended March 31, 2023 2022 Common stock warrants 7,208,193 — Common stock options 5,608,210 5,558,884 Total 12,816,403 5,558,884 Recent Accounting Pronouncements There are no

Note 3 - Fair Value of Financia

Note 3 - Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Fair Value Disclosures [Text Block]	3. The authoritative guidance with respect to fair value established a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three one three Level 1 1 Level 2 1, 2 Level 3 no not 3 The following table sets forth the fair value of the Company’s financial assets measured on a recurring basis as of March 31, 2023 December 31, 2022 March 31, 2023 Assets Classification Level 1 Level 2 Level 3 Total Money market funds Cash and cash equivalents $ 50,700 $ — $ — $ 50,700 Total assets measured at fair value $ 50,700 $ — $ — $ 50,700 December 31, 2022 Assets Classification Level 1 Level 2 Level 3 Total Money market funds Cash and cash equivalents $ 57,973 $ — $ — $ 57,973 Total assets measured at fair value $ 57,973 $ — $ — $ 57,973 The Company did not March 31, 2023 December 31, 2022

Note 4 - Balance Sheet Componen

Note 4 - Balance Sheet Components	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Supplemental Balance Sheet Disclosures [Text Block]	4. Property and Equipment, Net Property and equipment, net consisted of the following (in thousands): March 31, December 31, 2023 2022 Leasehold improvements $ 2,519 $ 2,519 Laboratory equipment 1,149 1,118 Furniture, fixtures and equipment 966 966 Software 289 289 Construction in progress 30 22 4,953 4,914 Less: Accumulated depreciation and amortization (3,088 ) (2,953 ) $ 1,865 $ 1,961 Depreciation expense was $0.1 million and $0.2 million for the three March 31, 2023 2022 Intangible Assets, Net Intangible assets primarily consist of acquired licenses to utilize certain patents, know-how and technology relating to the Company’s NPS technology for biomedical applications acquired from Old Dominion University Research Foundation (“ODURF”), Eastern Virginia Medical School, and the University of Southern California. In addition, the Company entered into a Sponsored Research Agreement with Old Dominion University’s Frank Reidy Research Center for Bioelectrics, which includes certain intellectual property rights arising from the research. The Company is amortizing the intangible assets over an estimated useful life of 12 years. Intangible assets, net consisted of the following (in thousands): March 31, December 31, 2023 2022 Acquired patents and licenses $ 7,985 $ 7,985 Less: Accumulated amortization (5,601 ) (5,434 ) $ 2,384 $ 2,551 A schedule of the amortization of intangible assets for the remainder of 2023 Years ending December 31: 2023 (remaining 9 months) $ 498 2024 665 2025 665 2026 556 $ 2,384 Accrued Expenses Accrued expenses consisted of the following (in thousands): March 31, December 31, 2023 2022 Compensation expense $ 1,615 $ 1,377 Director and officer liability insurance (Note 12) 815 571 Clinical trial fees and costs 49 64 Professional fees 351 318 Warranty 50 50 Other 211 215 $ 3,091 $ 2,595

Note 5 - Goodwill

Note 5 - Goodwill	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Goodwill Disclosure [Text Block]	5. In 2014, 805, Business Combinations In accordance with ASC Topic 350, Intangibles-Goodwill and Other 2017 04 not March 31, 2023 no

Note 6 - Stockholders' Equity a

Note 6 - Stockholders' Equity and Stock-based Compensation	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Share-Based Payment Arrangement [Text Block]	6. Equity and Stock-Based Compensation Rights Offering On June 9, 2022, “2022 one one “2022 one 2022 2022 2022 may 2022 2022 one Common Stock Warrants 2022 At-the-Market Equity Offering On February 4, 2021, may 415 1933, no not three March 31, 2023 2022, Common Stock Warrants In connection with the 2022 2022 2022 fifth 2022 2022 not may not three May 10, 2023, May 9, 2023 may June 16, 2023, three March 31, 2023 March 31, 2023 2022 Equity Plans 2017 2017 The Board of Directors of the Company (the “Board”) previously adopted, and the Company’s stockholders approved, the Company’s 2017 “2017 The 2017 may 2017 2015 “2015 not 2017 2017 January 1, 2023, 2017 2017 2017 December 31 March 31, 2023 2017 In November 2017, 2017 The Inducement Plan has a 10-year term, and provides for the grant of equity-based awards, including nonstatutory stock options, restricted stock units, restricted stock, stock appreciation rights, performance shares and performance units, and its terms are substantially similar to the 2017 may ten first not May 2021, March 31, 2023 A summary of stock option activity under the 2015 2017 three March 31, 2023 Stock Options Outstanding Number of shares Weighted average exercise price Weighted average remaining life (in years) Balances — December 31, 2022 5,250,696 $ 12.67 6.24 Options granted 807,300 2.92 Options exercised — — Options canceled (68,894 ) 11.24 Options expired (380,892 ) 13.07 Balances — March 31, 2023 5,608,210 $ 11.25 6.90 Exercisable — March 31, 2023 3,434,715 $ 14.72 5.66 Time-based Options The Company awards time-based options which vest and become exercisable, subject to the individual’s continued employment or service through the applicable vesting date. Time-based options can have various vesting schedules, most commonly new hire grants which generally vest 25% per year starting upon the first A summary of the time-based stock option activity under the 2015 2017 three March 31, 2023 Stock Options Outstanding Number of shares Weighted average exercise price Weighted average remaining life (in years) Balances — December 31, 2022 4,730,394 $ 12.95 6.16 Options granted 25,000 2.52 Options exercised — — Options canceled (68,894 ) 11.24 Options expired (302,720 ) 13.13 Balances — March 31, 2023 4,383,780 $ 12.91 6.34 Exercisable — March 31, 2023 3,226,526 $ 14.98 5.59 The fair value of the time-based options granted during the three March 31, 2023 Performance Options Certain stock options awarded by the Company contain performance conditions related to certain financial measures and achievements of strategic/operational milestones. The options will vest and become exercisable once the specific performance condition is fulfilled. A summary of the performance option activity under the 2017 three March 31, 2023 Stock Options Outstanding Number of shares Weighted average exercise price Weighted average remaining life (in years) Balances — December 31, 2022 520,302 $ 10.08 7.02 Options granted 782,300 2.92 Options exercised — — Options canceled — — Options expired (78,172 ) 12.84 Balances — March 31, 2023 1,224,430 $ 5.33 8.90 Exercisable — March 31, 2023 208,189 $ 10.72 6.71 The fair value of the performance options granted during the three March 31, 2023 The Company estimates the fair value of employee stock options on the grant date using the Black-Scholes option pricing model. The estimated fair value of employee stock options is amortized on a straight-line basis over the requisite service period of the awards. The Company reviews, and when deemed appropriate, updates the assumptions used on a periodic basis. The fair value of employee stock options was estimated using the following weighted-average assumptions: Three Months Ended March 31, 2023 2022 Expected term in years 6.03 6.3 - 6.8 Expected volatility 94% 83% Risk-free interest rate 3.80% 1.90% Dividend yield — — 2017 The Board previously adopted, and the Company's stockholders approved, the Company’s 2017 “2017 The 2017 2017 2017 December 31 2022 2023 no 2017 three March 31, 2023 2017 March 31, 2023 2017 The Company estimates the fair value of ESPP grants on their grant date using the Black-Scholes option pricing model. The estimated fair value of ESPP grants is amortized on a straight-line basis over the requisite service period of the grants. The Company reviews, and when deemed appropriate, updates the assumptions used on a periodic basis. The Company utilizes its estimated volatility in the Black-Scholes option pricing model to determine the fair value of ESPP grants. The fair value of ESPP grants was estimated using the following weighted-average assumptions: Three Months Ended March 31, 2023 2022 Expected term in years 0.5 - 1.0 0.5 - 1.0 Expected volatility 83% 83% Risk-free interest rate 5.1% - 5.2% 0.6% - 0.9% Dividend yield — — Stock-based Compensation Total stock-based compensation expense consisted of the following (in thousands): Three Months Ended March 31, 2023 2022 Cost of revenues $ — $ 90 Research and development 258 457 Sales and marketing — 454 General and administrative 638 1,006 Total stock-based compensation expense $ 896 $ 2,007 As of March 31, 2023 not Total stock-based compensation expense by type was as follows (in thousands): Three Months Ended March 31, 2023 2022 Time-based options $ 678 $ 1,807 Performance options 117 84 ESPP 101 116 Total stock-based compensation expense $ 896 $ 2,007

Note 7 - Research Grants and Ag

Note 7 - Research Grants and Agreements	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Research, Development, and Computer Software Disclosure [Text Block]	7. Sponsored Research Agreement The Company may March 2021, 12 May 2021, 12 may three March 31, 2023 2022 zero March 31, 2023 not

Note 8 - Commitments and Contin

Note 8 - Commitments and Contingencies	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	8. 2022 On September 20, 2022, “2022 January 1, 2023, March 20, 2024. March 17, 2023, no September 30, 2024. three March 31, 2023 2022 April 30, 2023, 2022 2022 no 2022 Operating Leases In January 2017, five July 2017. In May 2019, 1 1” 2”, October 2029 1 2. The Company evaluated the lease amendment under the provisions of ASC 842. not 1 November 2019) 2 May 2020) Supplemental balance sheet information related to leases (in thousands): March 31, December 31, Assets: 2023 2022 Right-of-use assets $ 7,869 $ 8,062 March 31, December 31, Liabilities: 2023 2022 Current operating lease liabilities $ 935 $ 896 Non-current operating lease liabilities 8,898 9,144 Total lease liabilities $ 9,833 $ 10,040 Total cash paid for operating lease liabilities (in thousands): Three Months Ended March 31, 2023 2022 Cash paid for operating lease liabilities $ 453 $ 447 Maturities of operating lease liabilities were as follows (in thousands): Year ending December 31: 2023 (remaining 9 months) $ 1,392 2024 1,910 2025 1,977 2026 2,046 2027 2,117 Thereafter 4,075 Total lease payments 13,517 Less imputed interest (3,684 ) Total lease liabilities $ 9,833 Weighted-average remaining lease term and discount rate, as of March 31, 2023, Weighted-average remaining lease term 6.59 Weighted-average discount rate 10 % Rent expense, including common area maintenance charges, was $0.5 million for each of the three March 31, 2023 2022 Legal Proceedings From time to time, we may may In November 2022, not not March 2023, one not

Note 9 - Controlled Launch

Note 9 - Controlled Launch	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Controlled Launch [Text Block]	9. Controlled Launch In February 2021, 510 January 2021, June 2021 February 2021, June 2021, As part of the Controlled Launch, the Company selected 70 physicians and their practices to be the first As patient procedures and surveys were completed under the Controlled Launch program, the Company accrued the value of the credits earned, which were recorded in accrued expenses, with a corresponding charge to sales and marketing expense. The Company did not three March 31, 2023 three March 31, 2022 In September 2022, fourth 2022 During the three March 31, 2023 not three March 31, 2022, three March 31, 2022. 10

Note 10 - Revenue

Note 10 - Revenue	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Revenue from Contract with Customer [Text Block]	10. The Company recognized revenue at a point in time when it satisfied performance obligations by transferring control of promised goods to its customers. The amount of revenue recognized was equal to the consideration which the Company was entitled to in exchange for the promised goods, excluding any amounts assessed by government authorities for taxes which might be collected from a customer. This consideration may September 20, 2022, three March 31, 2023 2022 zero zero Sales contracts often involve the sale and delivery of multiple performance obligations in the contract. Performance Obligations Systems consist of the CellFX console and its embedded software, handpieces, and disposable tips. The console is a physical piece of hardware used by the customer to perform patient procedures. Individually the console and software are not one Handpieces are attached to the console and used in conjunction with tips to perform patient procedures. Generally, upon initial sale of a system to a customer, the Company will include two Disposable treatment tips are single-patient multiple-use products that come in different sizes, each of which are to be used for specific procedures. Tips are attached to the handpiece for use in patient procedures and, upon detachment from the handpiece, a tip cannot be reused, and it must be disposed of. Tips represent a distinct performance obligation which is satisfied either upon shipment, or upon delivery of the tips to the customer, depending on the specific contract. CUs are credits that authorize the customer to perform a procedure, or cycle. Each procedure requires a specific number of CUs, dependent upon type of tip used and procedure level selected. As the procedure is performed, the applicable number of CUs are decremented. When the customer’s balance of CUs on a specific system is depleted, the system will no not Shipping and handling activities are not Transaction Price The transaction price is the consideration to which the Company expects to be entitled to in exchange for providing the promised goods to customers. Customer orders placed for cash contemplate a fixed amount of consideration. Customer orders placed by physicians participating in the Controlled Launch when they elected to purchase the CellFX System were paid for via conversion of accumulated earned credits for prior services provided by the physicians under the terms of their participation in the Controlled Launch. For these transactions, the transaction price included noncash consideration. The services rendered by the physicians in the Controlled Launch were accounted for separately from the subsequent sales of the CellFX Systems because they were distinct from the system sales. They were distinct because they provided the Company with treatment data that could also be procured, and historically had been procured by the Company, without the corresponding system sales. This data was used by the Company to enhance marketing and promotion of its products. The Company evaluates the possible impact of variable consideration in determining the transaction price, in particular the possibility of future returns or credits. Sales agreements allow for a right of return only if the product does not no The Company has made an accounting policy election to exclude from the measurement of the transaction price all taxes which are imposed on and concurrent with a specific revenue-producing transaction and collected by the entity from a customer. When there are multiple performance obligations present, the total transaction price shall be allocated to each of the performance obligations based upon the relative SSPs of those performance obligations. The Company establishes SSPs based on multiple factors including, prices charged by the Company for similar offerings, product-specific business objectives, and the estimated cost to provide the performance obligation. However, upon the sale of a new CellFX System, all performance obligations are delivered concurrently and therefore there is no not no Controlled Launch Agreements In August 2021 8

Note 11 - Segment Reporting

Note 11 - Segment Reporting	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Segment Reporting Disclosure [Text Block]	11. The Company operates and manages the business as one reportable and operating segment. The Company’s Chief Executive Officer acts as the chief operating decision maker (“CODM”) of the Company. The CODM reviews the results of the Company on a consolidated basis, however in making certain operating decisions and assessing performance, the CODM will additionally review the disaggregated revenue results by product and geography. Substantially all of the Company’s long-lived assets are based in the United States. Revenue by product consisted of the following (in thousands): Three Months Ended March 31, 2023 2022 Systems $ — $ 367 Cycle units — 77 Total consolidated revenue $ — $ 444 Revenue by geography consisted of the following (in thousands): Three Months Ended March 31, 2023 2022 North America $ — $ 312 Rest of World — 132 Total consolidated revenue $ — $ 444

Note 12 - Related Party Transac

Note 12 - Related Party Transactions	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Related Party Transactions Disclosure [Text Block]	12. Related Party Transactions In May 2022, not May 31, 2022, one third May 31, 2023, one March 31, 2023 On September 20, 2022, 2022 April 30, 2023, 2022 2022 no 2022 8

Note 13 - Restructuring Charges

Note 13 - Restructuring Charges	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Restructuring and Related Activities Disclosure [Text Block]	13. Restructuring Charges On March 31, 2022, March 31, 2022. March 2022 three March 31, 2022. In February 2023, seven February 2023 three March 31, 2023.

Note 14 - Subsequent Events

Note 14 - Subsequent Events	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Subsequent Events [Text Block]	14. Subsequent Events On April 30, 2023, May 9, 2023, 2022 September 20, 2022, 2022 no 2022

Significant Accounting Policies

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared on a basis consistent with the Company’s December 31, 2022 December 31, 2022 not 10 December 31, 2022 three March 31, 2023, not
Consolidation, Policy [Policy Text Block]	Principles of Consolidation The accompanying condensed consolidated financial statements include the financial statements of Pulse Biosciences, Inc. and its wholly-owned subsidiaries. Intercompany balances and transactions, if any, have been eliminated in consolidation.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires the Company to make estimates and assumptions that affect the amounts reported in the Financial Statements and accompanying notes to the condensed consolidated financial statements. Estimates include, but are not
Inventory, Policy [Policy Text Block]	Valuation of Inventory Inventory is stated at lower of cost or net realizable value. The Company establishes the inventory basis by determining the cost based on standard costs approximating the purchase costs on a first first December 31, 2022, not
Revenue from Contract with Customer [Policy Text Block]	Revenue from Contracts with Customers The Company recognized revenue at a point in time when it satisfied performance obligations by transferring control of promised goods to its customers. The amount of revenue recognized was equal to the consideration which the Company was entitled to in exchange for the promised goods, excluding any amounts assessed by government authorities for taxes which might have been collected from a customer. Sales contracts often involved the sale and delivery of multiple products, each of which typically represented a separate performance obligation in the contract. While the Company has sold these products on a stand-alone basis at their respective stand-alone selling prices (“SSP”), initial customer contracts primarily involved the bundling of products which were delivered concurrently to the customer. In such instances, the full consideration of the contract was recognized upon shipment of the products. The Company generally required receipt of full payment prior to shipment, however, from time to time, payment terms were extended to customers upon which the Company performed a necessary credit evaluation to ensure future collectability of the outstanding balance. The accounts receivable balance at March 31, 2023 zero not 10
Standard Product Warranty, Policy [Policy Text Block]	Product Warranty The Company provides a standard warranty on eligible products which provides the customer assurances that the products comply with the agreed-upon specifications. The standard warranty does not may Warranty accrual activity consisted of the following for the three March 31, 2023 2022 Three Months Ended March 31, 2023 2022 Beginning balance $ 50 $ 80 Add: Accruals for warranties issued during the period — 17 Less: Adjustment for inventory at cost and excessive and obsolete inventory — — Ending balance $ 50 $ 97
Earnings Per Share, Policy [Policy Text Block]	Net Loss per Share The Company calculates basic net loss per share by dividing net loss by the weighted-average number of shares of common stock outstanding during the period. Diluted net loss per share is computed by giving effect to all potential dilutive common stock equivalents outstanding during the period. For purposes of this calculation, options to purchase common stock and common stock warrants are considered common stock equivalents. Potential common shares that have an anti-dilutive effect (i.e., those that increase income per share or decrease loss per share) are excluded from the calculation of diluted net loss per share. Basic and diluted net loss per common share is the same for all periods presented because all warrants, stock options and restricted stock units outstanding are anti-dilutive. The following outstanding stock options, and warrants were excluded from the computation of diluted net loss per share for the periods presented because including them would have had an anti-dilutive effect: Three Months Ended March 31, 2023 2022 Common stock warrants 7,208,193 — Common stock options 5,608,210 5,558,884 Total 12,816,403 5,558,884
New Accounting Pronouncements, Policy [Policy Text Block]	Recent Accounting Pronouncements There are no

Note 2 - Summary of Significa_2

Note 2 - Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Schedule of Product Warranty Liability [Table Text Block]	Three Months Ended March 31, 2023 2022 Beginning balance $ 50 $ 80 Add: Accruals for warranties issued during the period — 17 Less: Adjustment for inventory at cost and excessive and obsolete inventory — — Ending balance $ 50 $ 97
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	Three Months Ended March 31, 2023 2022 Common stock warrants 7,208,193 — Common stock options 5,608,210 5,558,884 Total 12,816,403 5,558,884

Note 3 - Fair Value of Financ_2

Note 3 - Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Fair Value, Assets Measured on Recurring Basis [Table Text Block]	March 31, 2023 Assets Classification Level 1 Level 2 Level 3 Total Money market funds Cash and cash equivalents $ 50,700 $ — $ — $ 50,700 Total assets measured at fair value $ 50,700 $ — $ — $ 50,700 December 31, 2022 Assets Classification Level 1 Level 2 Level 3 Total Money market funds Cash and cash equivalents $ 57,973 $ — $ — $ 57,973 Total assets measured at fair value $ 57,973 $ — $ — $ 57,973

Note 4 - Balance Sheet Compon_2

Note 4 - Balance Sheet Components (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Property, Plant and Equipment [Table Text Block]	March 31, December 31, 2023 2022 Leasehold improvements $ 2,519 $ 2,519 Laboratory equipment 1,149 1,118 Furniture, fixtures and equipment 966 966 Software 289 289 Construction in progress 30 22 4,953 4,914 Less: Accumulated depreciation and amortization (3,088 ) (2,953 ) $ 1,865 $ 1,961
Schedule of Finite-Lived Intangible Assets [Table Text Block]	March 31, December 31, 2023 2022 Acquired patents and licenses $ 7,985 $ 7,985 Less: Accumulated amortization (5,601 ) (5,434 ) $ 2,384 $ 2,551
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	Years ending December 31: 2023 (remaining 9 months) $ 498 2024 665 2025 665 2026 556 $ 2,384
Schedule of Accrued Liabilities [Table Text Block]	March 31, December 31, 2023 2022 Compensation expense $ 1,615 $ 1,377 Director and officer liability insurance (Note 12) 815 571 Clinical trial fees and costs 49 64 Professional fees 351 318 Warranty 50 50 Other 211 215 $ 3,091 $ 2,595

Note 6 - Stockholders' Equity_2

Note 6 - Stockholders' Equity and Stock-based Compensation (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]	Three Months Ended March 31, 2023 2022 Cost of revenues $ — $ 90 Research and development 258 457 Sales and marketing — 454 General and administrative 638 1,006 Total stock-based compensation expense $ 896 $ 2,007
Share-Based Payment Arrangement, Cost by Plan [Table Text Block]	Three Months Ended March 31, 2023 2022 Time-based options $ 678 $ 1,807 Performance options 117 84 ESPP 101 116 Total stock-based compensation expense $ 896 $ 2,007
Share-Based Payment Arrangement, Option [Member]
Notes Tables
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	Three Months Ended March 31, 2023 2022 Expected term in years 6.03 6.3 - 6.8 Expected volatility 94% 83% Risk-free interest rate 3.80% 1.90% Dividend yield — —
Performance Options [Member]
Notes Tables
Share-Based Payment Arrangement, Option, Activity [Table Text Block]	Stock Options Outstanding Number of shares Weighted average exercise price Weighted average remaining life (in years) Balances — December 31, 2022 520,302 $ 10.08 7.02 Options granted 782,300 2.92 Options exercised — — Options canceled — — Options expired (78,172 ) 12.84 Balances — March 31, 2023 1,224,430 $ 5.33 8.90 Exercisable — March 31, 2023 208,189 $ 10.72 6.71
Time-based Options [Member]
Notes Tables
Share-Based Payment Arrangement, Option, Activity [Table Text Block]	Stock Options Outstanding Number of shares Weighted average exercise price Weighted average remaining life (in years) Balances — December 31, 2022 4,730,394 $ 12.95 6.16 Options granted 25,000 2.52 Options exercised — — Options canceled (68,894 ) 11.24 Options expired (302,720 ) 13.13 Balances — March 31, 2023 4,383,780 $ 12.91 6.34 Exercisable — March 31, 2023 3,226,526 $ 14.98 5.59
The 2017 Employee Stock Purchase Plan [Member]
Notes Tables
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	Three Months Ended March 31, 2023 2022 Expected term in years 0.5 - 1.0 0.5 - 1.0 Expected volatility 83% 83% Risk-free interest rate 5.1% - 5.2% 0.6% - 0.9% Dividend yield — —
The 2015 Plan, 2017 Plan and Inducement Plan [Member]
Notes Tables
Share-Based Payment Arrangement, Option, Activity [Table Text Block]	Stock Options Outstanding Number of shares Weighted average exercise price Weighted average remaining life (in years) Balances — December 31, 2022 5,250,696 $ 12.67 6.24 Options granted 807,300 2.92 Options exercised — — Options canceled (68,894 ) 11.24 Options expired (380,892 ) 13.07 Balances — March 31, 2023 5,608,210 $ 11.25 6.90 Exercisable — March 31, 2023 3,434,715 $ 14.72 5.66

Note 8 - Commitments and Cont_2

Note 8 - Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Schedule of Information Related to Right-of-use Assets and Lease Liabilities [Table Text Block]	March 31, December 31, Assets: 2023 2022 Right-of-use assets $ 7,869 $ 8,062 March 31, December 31, Liabilities: 2023 2022 Current operating lease liabilities $ 935 $ 896 Non-current operating lease liabilities 8,898 9,144 Total lease liabilities $ 9,833 $ 10,040 Three Months Ended March 31, 2023 2022 Cash paid for operating lease liabilities $ 453 $ 447 Year ending December 31: 2023 (remaining 9 months) $ 1,392 2024 1,910 2025 1,977 2026 2,046 2027 2,117 Thereafter 4,075 Total lease payments 13,517 Less imputed interest (3,684 ) Total lease liabilities $ 9,833 Weighted-average remaining lease term 6.59 Weighted-average discount rate 10 %

Note 11 - Segment Reporting (Ta

Note 11 - Segment Reporting (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Disaggregation of Revenue [Table Text Block]	Three Months Ended March 31, 2023 2022 Systems $ — $ 367 Cycle units — 77 Total consolidated revenue $ — $ 444
Revenue from External Customers by Geographic Areas [Table Text Block]	Three Months Ended March 31, 2023 2022 North America $ — $ 312 Rest of World — 132 Total consolidated revenue $ — $ 444

Note 2 - Summary of Significa_3

Note 2 - Summary of Significant Accounting Policies - Warrant Accrual Activity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Beginning balance	$ 50	$ 80
Add: Accruals for warranties issued during the period	0	17
Less: Adjustment for inventory at cost and excessive and obsolete inventory	0	0
Ending balance	$ 50	$ 97

Note 2 - Summary of Significa_4

Note 2 - Summary of Significant Accounting Policies - Antidilutive Securities (Details) - shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Antidilutive securities (in shares)	12,816,403	5,558,884
Warrant [Member]
Antidilutive securities (in shares)	7,208,193	0
Share-Based Payment Arrangement, Option [Member]
Antidilutive securities (in shares)	5,608,210	5,558,884

Note 3 - Fair Value of Financ_3

Note 3 - Fair Value of Financial Instruments (Details Textual) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Fair Value, Recurring [Member]
Liabilities, Fair Value Disclosure	$ 0	$ 0

Note 3 - Investments and Fair V

Note 3 - Investments and Fair Value of Financial Instruments - Financial Assets Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Total assets measured at fair value	$ 50,700	$ 57,973
Total assets measured at fair value	(50,700)	(57,973)
Fair Value, Inputs, Level 1 [Member]
Total assets measured at fair value	50,700	57,973
Total assets measured at fair value	(50,700)	(57,973)
Fair Value, Inputs, Level 2 [Member]
Cash and Cash equivalents		0
Total assets measured at fair value	0
Total assets measured at fair value	0
Fair Value, Inputs, Level 3 [Member]
Total assets measured at fair value	0	0
Total assets measured at fair value	0	0
Money Market Funds [Member]
Cash and Cash equivalents	50,700	57,973
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Cash and Cash equivalents	50,700	57,973
Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Cash and Cash equivalents	0	0
Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Cash and Cash equivalents	$ 0	$ 0

Note 4 - Balance Sheet Compon_3

Note 4 - Balance Sheet Components (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Depreciation	$ 135	$ 160
Finite-Lived Intangible Asset, Useful Life (Year)	12 years

Note 4 - Balance Sheet Compon_4

Note 4 - Balance Sheet Components - Property and Equipment, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Property and equipment, gross	$ 4,953	$ 4,914
Less: Accumulated depreciation and amortization	(3,088)	(2,953)
Property and equipment, net	1,865	1,961
Leasehold Improvements [Member]
Property and equipment, gross	2,519	2,519
Laboratory Equipment [Member]
Property and equipment, gross	1,149	1,118
Furniture and Fixtures [Member]
Property and equipment, gross	966	966
Software and Software Development Costs [Member]
Property and equipment, gross	289	289
Construction in Progress [Member]
Property and equipment, gross	$ 30	$ 22

Note 4 - Balance Sheet Compon_5

Note 4 - Balance Sheet Components - Intangible Assets, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Less: Accumulated amortization	$ (5,601)	$ (5,434)
Finite-Lived Intangible Assets, Net	2,384	2,551
Acquired Patents and Licenses [Member]
Acquired patents and licenses	$ 7,985	$ 7,985

Note 4 - Balance Sheet Compon_6

Note 4 - Balance Sheet Components - Schedule of Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
2023 (remaining 9 months)	$ 498
2024	665
2025	665
2026	556
Finite-Lived Intangible Assets, Net	$ 2,384	$ 2,551

Note 4 - Balance Sheet Compon_7

Note 4 - Balance Sheet Components - Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Compensation expense	$ 1,615	$ 1,377
Director and officer liability insurance (Note 12)	815	571
Clinical trial fees and costs	49	64
Professional fees	351	318
Warranty	50	50	$ 97	$ 80
Other	211	215
Accrued Liabilities, Current	$ 3,091	$ 2,595

Note 5 - Goodwill (Details Text

Note 5 - Goodwill (Details Textual) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2023 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2022 USD ($)
Goodwill, Ending Balance	$ 2,791		$ 2,791
Goodwill, Impairment Loss	$ 0
Series of Individually Immaterial Business Acquisitions [Member]
Number of Businesses Acquired		3
Business Combination, Consideration Transferred, Total		$ 5,500
Goodwill, Ending Balance		$ 2,800

Note 6 - Stockholders' Equity_3

Note 6 - Stockholders' Equity and Stock-based Compensation (Details Textual) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended		3 Months Ended	12 Months Ended
	Jan. 01, 2023	Jun. 09, 2022	May 31, 2021	Nov. 30, 2017	Mar. 31, 2023	Dec. 31, 2017	Dec. 31, 2022	Feb. 04, 2021
Common Stock, Par or Stated Value Per Share (in dollars per share)					$ 0.001		$ 0.001
Time-based Options [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Intrinsic Value					$ 49
Time-based Options [Member] | Share-Based Payment Arrangement, Tranche One [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage					25%
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)					1 year
Performance Options [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Intrinsic Value					$ 1,800
The 2017 Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period (Year)						10 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares)						1,500,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Additional Shares Authorized (in shares)	1,200,000
Increase in Shares Available for Issuance, Threshold of Common Stock Outstanding, Number of Shares (in shares)						1,200,000
Increase in Shares Available for Issuance, Threshold of Common Stock Outstanding, Percent						4%
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)					3,136,838
The 2017 Inducement Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period (Year)				10 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares)				1,000,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Additional Shares Authorized (in shares)			1,000,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)					1,140,501
The 2017 Inducement Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Tranche One [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage				25%
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)				1 year
The 2017 Employee Stock Purchase Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares)						250,000
Increase in Shares Available for Issuance, Threshold of Common Stock Outstanding, Number of Shares (in shares)						450,000
Increase in Shares Available for Issuance, Threshold of Common Stock Outstanding, Percent						1.50%
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)					198,529
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares)					262,470
Maximum [Member] | The 2017 Inducement Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period (Year)				10 years
Rights Offering Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)		1
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)					7,317,072
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)		$ 2.05			$ 2.05
Warrants and Rights Outstanding, Term (Year)					5 years
Class of Warrants or Rights, Redemption Price Per Share (in dollars per share)					$ 0.01
Class of Warrant or Right, Period of Written Notice for Exercise (Year)					30 years
Class of Warrant or Right, Percentage Required for Redemption					200%
Class of Warrant or Right, Exercise, Consecutive Trading Days (Year)					20 years
Class of Warrant or Right, Exercised During Period (in shares)					95,639
Class of Warrant or Right, Outstanding (in shares)					7,208,193
Rights Offering Warrants [Member] | Maximum [Member]
Additional Proceeds That May be Received Upon Exercise of Warrants		$ 15,000
Rights Offering [Member]
Equity Offering, Units, Sale of Units (in shares)		7,317,072
Shares Issued, Price Per Share (in dollars per share)		$ 2.05
Number of Shares Per Unit Issued (in shares)		1
Common Stock, Par or Stated Value Per Share (in dollars per share)		$ 0.001
Number of Warrants Per Unit (in shares)		1
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)		1
Stock Issued During Period, Shares, New Issues (in shares)		7,317,072
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		7,317,072
Proceeds from Issuance of Common Stock		$ 15,000
Rights Offering [Member] | Board of Directors Chairman [Member]
Investment Owned, Percent of Net Assets		56%
ATM Offering [Member]
Equity Offering, Maximum Offering Amount								$ 60,000

Note 6 - Stockholders' Equity_4

Note 6 - Stockholders' Equity and Stock-based Compensation - Summary of Stock Option Activity (Details) - The 2015 Plan, 2017 Plan and Inducement Plan [Member] - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Options balances, number of shares (in shares)	5,250,696
Options balances, weighted average exercise price (in dollars per share)	$ 12.67
Options balances, weighted average remaining life (Year)	6 years 10 months 24 days	6 years 2 months 26 days
Options granted, number of shares (in shares)	807,300
Options granted, weighted average exercise price (in dollars per share)	$ 2.92
Options exercised, number of shares (in shares)	0
Options exercised, weighted average exercise price (in dollars per share)	$ 0
Options canceled, number of shares (in shares)	(68,894)
Options canceled, weighted average exercise price (in dollars per share)	$ 11.24
Options expired, number of shares (in shares)	(380,892)
Options expired, weighted average exercise price (in dollars per share)	$ 13.07
Options balances, number of shares (in shares)	5,608,210	5,250,696
Options balances, weighted average exercise price (in dollars per share)	$ 11.25	$ 12.67
Options exercisable, number of shares (in shares)	3,434,715
Options exercisable, weighted average exercise price (in dollars per share)	$ 14.72
Options exercisable, weighted average remaining life (Year)	5 years 7 months 28 days

Note 6 - Stockholders' Equity_5

Note 6 - Stockholders' Equity and Stock-based Compensation - Summary of Time-based Option Activity (Details) - Time-based Options [Member] - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Options balances, number of shares (in shares)	4,730,394
Options balances, weighted average exercise price (in dollars per share)	$ 12.95
Options balances, weighted average remaining life (Year)	6 years 4 months 2 days	6 years 1 month 28 days
Options granted, number of shares (in shares)	25,000
Options granted, weighted average exercise price (in dollars per share)	$ 2.52
Options exercised, number of shares (in shares)	0
Options exercised, weighted average exercise price (in dollars per share)	$ 0
Options canceled, number of shares (in shares)	(68,894)
Options canceled, weighted average exercise price (in dollars per share)	$ 11.24
Options expired, number of shares (in shares)	(302,720)
Options expired, weighted average exercise price (in dollars per share)	$ 13.13
Options balances, number of shares (in shares)	4,383,780	4,730,394
Options balances, weighted average exercise price (in dollars per share)	$ 12.91	$ 12.95
Options exercisable, number of shares (in shares)	3,226,526
Options exercisable, weighted average exercise price (in dollars per share)	$ 14.98
Options exercisable, weighted average remaining life (Year)	5 years 7 months 2 days

Note 6 - Stockholders' Equity_6

Note 6 - Stockholders' Equity and Stock-based Compensation - Summary of Performance Option Activity (Details) - Performance Options [Member] - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Options balances, number of shares (in shares)	520,302
Options balances, weighted average exercise price (in dollars per share)	$ 10.08
Options balances, weighted average remaining life (Year)	8 years 10 months 24 days	7 years 7 days
Options granted, number of shares (in shares)	782,300
Options granted, weighted average exercise price (in dollars per share)	$ 2.92
Options exercised, number of shares (in shares)	0
Options exercised, weighted average exercise price (in dollars per share)	$ 0
Options canceled, number of shares (in shares)	0
Options canceled, weighted average exercise price (in dollars per share)	$ 0
Options expired, number of shares (in shares)	(78,172)
Options expired, weighted average exercise price (in dollars per share)	$ 12.84
Options balances, number of shares (in shares)	1,224,430	520,302
Options balances, weighted average exercise price (in dollars per share)	$ 5.33	$ 10.08
Options exercisable, number of shares (in shares)	208,189
Options exercisable, weighted average exercise price (in dollars per share)	$ 10.72
Options exercisable, weighted average remaining life (Year)	6 years 8 months 15 days

Note 6 - Stockholders' Equity_7

Note 6 - Stockholders' Equity and Stock-based Compensation - Option Assumptions (Details) - Share-Based Payment Arrangement, Option [Member]	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Expected term in years (Year)	6 years 10 days
Expected volatility	94%	83%
Risk-free interest rate	3.80%	1.90%
Dividend yield
Minimum [Member]
Expected term in years (Year)		6 years 3 months 18 days
Maximum [Member]
Expected term in years (Year)		6 years 9 months 18 days

Note 6 - Stockholders' Equity_8

Note 6 - Stockholders' Equity and Stock-based Compensation - ESPP Assumptions (Details) - The 2017 Employee Stock Purchase Plan [Member]	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Expected volatility	83%	83%
Dividend yield	0%	0%
Minimum [Member]
Expected term in years (Year)	6 months	6 months
Risk-free interest rate	5.10%	0.60%
Maximum [Member]
Expected term in years (Year)	1 year	1 year
Risk-free interest rate	5.20%	0.90%

Note 6 - Stockholders' Equity_9

Note 6 - Stockholders' Equity and Stock-based Compensation - Stock-based Compensation Expense by Recorded Location (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Total stock-based compensation expense	$ 896	$ 2,007
Cost of Sales [Member]
Total stock-based compensation expense	0	90
Research and Development Expense [Member]
Total stock-based compensation expense	258	457
Selling and Marketing Expense [Member]
Total stock-based compensation expense	0	454
General and Administrative Expense [Member]
Total stock-based compensation expense	$ 638	$ 1,006

Note 6 - Stockholders' Equit_10

Note 6 - Stockholders' Equity and Stock-based Compensation - Stock-based Compensation Expense by Type (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Total stock-based compensation expense	$ 896	$ 2,007
Time-based Options [Member]
Total stock-based compensation expense	678	1,807
Performance Options [Member]
Total stock-based compensation expense	117	84
Employee Stock Purchase Plan Award [Member]
Total stock-based compensation expense	$ 101	$ 116

Note 7 - Research Grants and _2

Note 7 - Research Grants and Agreements (Details Textual) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended
	May 31, 2021	Mar. 31, 2021	Mar. 31, 2023	Mar. 31, 2022
Research and Development Expense			$ 5,829	$ 6,769
Old Dominion University Research Foundation [Member] | Sponsored Research Agreement SRA [Member]
Research and Development Expense			$ 0	$ 100
Old Dominion University Research Foundation [Member] | Sponsored Research Agreement SRA [Member] | Research and Development Arrangement [Member]
Long-Term Purchase Commitment, Amount	$ 300	$ 300

Note 8 - Commitments and Cont_3

Note 8 - Commitments and Contingencies (Details Textual) $ / shares in Units, $ in Millions		3 Months Ended
	Apr. 30, 2023 USD ($) $ / shares shares	Mar. 31, 2023 USD ($) $ / shares	Mar. 31, 2022 USD ($)	Dec. 31, 2022 $ / shares	Sep. 20, 2022 USD ($)	May 31, 2019 a	Jul. 31, 2017 a
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares		$ 0.001		$ 0.001
Operating Lease, Expense		$ 0.5	$ 0.5
Corporate Headquarters in Hayward, California [Member]
Lessee, Operating Lease, Term of Contract (Year)							5 years
Area of Real Estate Property (Acre) | a							15,700
Corporate Headquarters in Hayward, California [Member] | Expansion Premises 1 [Member]
Area of Real Estate Property (Acre) | a						13,300
Corporate Headquarters in Hayward, California [Member] | Expansion Premises 2 [Member]
Area of Real Estate Property (Acre) | a						21,300
Robert W. Duggan [Member] | Subsequent Event [Member] | Private Placement [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares	10,022,937
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares	$ 0.001
Shares Issued, Price Per Share (in dollars per share) | $ / shares	$ 6.51
Two Thousand Twenty Two Loan Agreement [Member] | Robert W. Duggan [Member]
Debt Instrument, Face Amount					$ 65
Debt Instrument Quarterly Interest Rate					5
Debt Instrument, Increase, Accrued Interest		0.9
Interest Expense		$ 0.8
Loan Agreement [Member] | Subsequent Event [Member]
Debt Instrument, Decrease, Forgiveness	$ 65

Note 8 - Commitments and Cont_4

Note 8 - Commitments and Contingencies - Information Related to Right-of-use Assets and Lease Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Right-of-use assets	$ 7,869		$ 8,062
Current operating lease liabilities	935		896
Non-current operating lease liabilities	8,898		9,144
Total lease liabilities	9,833		$ 10,040
Cash paid for operating lease liabilities	453	$ 447
2023 (remaining 9 months)	1,392
2024	1,910
2025	1,977
2026	2,046
2027	2,117
Thereafter	4,075
Total lease payments	13,517
Less imputed interest	$ (3,684)
Weighted-average remaining lease term (Year)	6 years 7 months 2 days
Weighted-average discount rate	10%

Note 9 - Controlled Launch (Det

Note 9 - Controlled Launch (Details Textual) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Feb. 28, 2021
Number of KOLs			70
Controlled Launch, Program Expenses	$ 0	$ 300
Revenue from Contract with Customer, Excluding Assessed Tax	0	444
Redemption of Non Cash Credits [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 0	$ 300
Minimum [Member]
Number of Patients Participating in Procedure			40
Maximum [Member]
Number of Patients Participating in Procedure			50

Note 10 - Revenue (Details Text

Note 10 - Revenue (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenue from Contract with Customer, Excluding Assessed Tax	$ 0	$ 444
Redemption of Non Cash Credits [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 0	$ 300

Note 11 - Segment Reporting (De

Note 11 - Segment Reporting (Details Textual)	3 Months Ended
	Mar. 31, 2023
Number of Reportable Segments	1

Note 11 - Segment Reporting - R

Note 11 - Segment Reporting - Revenue by Product (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Total revenues	$ 0	$ 444
System Products [Member]
Total revenues	0	367
Cycle Units Products [Member]
Total revenues	$ 0	$ 77

Note 11 - Segment Reporting -_2

Note 11 - Segment Reporting - Revenue by Geography (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Total revenues	$ 0	$ 444
North America [Member]
Total revenues	0	312
Rest of World [Member]
Total revenues	$ 0	$ 132

Note 12 - Related Party Trans_2

Note 12 - Related Party Transactions (Details Textual) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended
	Apr. 30, 2023	Sep. 20, 2022	Mar. 31, 2023	Dec. 31, 2022
Accrued Liabilities, Current			$ 3,091	$ 2,595
Common Stock, Par or Stated Value Per Share (in dollars per share)			$ 0.001	$ 0.001
Subsequent Event [Member] | Loan Agreement [Member]
Debt Instrument, Decrease, Forgiveness	$ 65,000
Robert W. Duggan [Member] | Subsequent Event [Member] | Private Placement [Member]
Stock Issued During Period, Shares, New Issues (in shares)	10,022,937
Common Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.001
Shares Issued, Price Per Share (in dollars per share)	$ 6.51
Letter Agreement [Member] | Robert W. Duggan [Member]
Directors and Officers Liability Insurance, Period (Year)			1 year
Fee Payable to Related Party			$ 1,000
Accrued Liabilities, Current			$ 800
Related Party Transaction, Amounts of Transaction		$ 65,000

Note 13 - Restructuring Charg_2

Note 13 - Restructuring Charges (Details Textual) - Employee Severance [Member] $ in Millions	1 Months Ended
	Feb. 28, 2023 USD ($)	Mar. 31, 2022 USD ($)
Restructuring and Related Cost, Number of Positions Eliminated	7
Total Cost and Expenses [Member]
Restructuring Charges	$ 0.1
Total Cost and Expenses [Member] | March 2022 Restructuring Plan [Member]
Restructuring Charges		$ 0.7

Note 14 - Subsequent Events (De

Note 14 - Subsequent Events (Details Textual) - USD ($) $ / shares in Units, $ in Millions	Apr. 30, 2023	Mar. 31, 2023	Dec. 31, 2022
Common Stock, Par or Stated Value Per Share (in dollars per share)		$ 0.001	$ 0.001
Subsequent Event [Member] | Loan Agreement [Member]
Debt Instrument, Decrease, Forgiveness	$ 65
Subsequent Event [Member] | Private Placement [Member] | Robert W. Duggan [Member]
Stock Issued During Period, Shares, New Issues (in shares)	10,022,937
Common Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.001
Shares Issued, Price Per Share (in dollars per share)	$ 6.51