Pulse Biosciences (PLSE) 10-Q 10 Aug 23 2023 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2023	Jul. 31, 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	Q2
Document Fiscal Year Focus	2023
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 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		54,902,942

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 58,747	$ 61,139
Prepaid expenses and other current assets	1,211	1,008
Total current assets	59,958	62,147
Property and equipment, net	1,755	1,961
Intangible assets, net	2,218	2,551
Goodwill	2,791	2,791
Right-of-use assets	7,670	8,062
Other assets	365	365
Total assets	74,757	77,877
Current liabilities:
Accounts payable	1,794	1,573
Accrued expenses	2,844	2,595
Lease liability, current	975	896
Related party note payable, current	0	917
Total current liabilities	5,613	5,981
Lease liability, less current portion	8,644	9,144
Related party note payable, less current	0	65,000
Total liabilities	14,257	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 – 54,771 shares and 37,235 shares at June 30, 2023 and December 31, 2022, respectively	55	37
Additional paid-in capital	374,861	292,420
Accumulated other comprehensive income (loss)	0	0
Accumulated deficit	(314,416)	(294,705)
Total stockholders’ equity (deficit)	60,500	(2,248)
Total liabilities and stockholders’ equity	$ 74,757	$ 77,877

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares shares in Thousands	Jun. 30, 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)	54,771	37,235
Common stock, shares outstanding (in shares)	54,771	37,235

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenues:
Total revenues	$ 0	$ 265	$ 0	$ 709
Cost and expenses:
Cost of revenues	0	1,344	0	2,253
Research and development	6,697	5,458	12,526	12,227
Sales and marketing	0	3,690	0	9,231
General and administrative	3,530	3,787	7,263	8,285
Total cost and expenses	10,227	14,279	19,789	31,996
Loss from operations	(10,227)	(14,014)	(19,789)	(31,287)
Other income:
Interest income, net	317	18	78	18
Total other income	317	18	78	18
Loss from operations, before income taxes	(9,910)	(13,996)	(19,711)	(31,269)
Income tax benefit	0	0	0	0
Net loss	(9,910)	(13,996)	(19,711)	(31,269)
Other comprehensive gain (loss):
Unrealized gain (loss) on available-for-sale securities	0	0	0	0
Comprehensive loss	$ (9,910)	$ (13,996)	$ (19,711)	$ (31,269)
Net loss per share:
Basic and diluted net loss per share (in dollars per share)	$ (0.22)	$ (0.44)	$ (0.48)	$ (1.02)
Weighted average shares used to compute net loss per common share — basic and diluted (in shares)	44,512	31,492	40,970	30,623
Product [Member]
Revenues:
Total revenues	$ 0	$ 265	$ 0	$ 709

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities:
Net loss	$ (19,711)	$ (31,269)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	271	347
Amortization of intangible assets	333	333
Stock-based compensation	2,039	3,720
Changes in operating assets and liabilities:
Accounts receivable	0	53
Inventory	0	(2,047)
Prepaid expenses and other current assets	(309)	1,112
Other receivables	106	(30)
Right-of-use assets	392	352
Accounts payable	212	(931)
Accrued expenses	239	296
Deferred revenue	0	16
Lease liabilities	(421)	(369)
Accrued interest on related party note payable	1,077	0
Accrued interest on note payable	0	1
Net cash used in operating activities	(15,772)	(28,416)
Cash flows from investing activities:
Purchases of property and equipment	(55)	(298)
Net cash used in investing activities	(55)	(298)
Cash flows from financing activities:
Proceeds from issuance of common stock under employee stock purchase plan	292	372
Proceeds from issuance of common stock	0	14,963
Proceeds from exercises of warrants	14,835	0
Proceeds from exercises of stock options	58	0
Payments made on insurance loan agreement	0	(437)
Issuance cost in relation to related party note extinguishment	(5)	0
Payments made on related party note	(1,745)	0
Net cash provided by financing activities	13,435	14,898
Net decrease in cash and cash equivalents	(2,392)	(13,816)
Cash and cash equivalents at beginning of period	61,139	28,614
Cash and cash equivalents at end of period	58,747	14,798
Supplemental disclosure of noncash investing and financing activities:
Principal and accrued interest of related party note settled via issuance of common stock	65,248	0
Equipment purchases included in accounts payable and accrued expenses	10	(27)
Other receivable from issuance of common stock	0	13
Issuance costs in accounts payable and accrued expenses	$ (8)	$ (74)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Private Placement [Member] Common Stock [Member]	Private Placement [Member] Additional Paid-in Capital [Member]	Private Placement [Member] AOCI Attributable to Parent [Member]	Private Placement [Member] Retained Earnings [Member]	Private Placement [Member]	Rights Offering [Member] Common Stock [Member]	Rights Offering [Member] Additional Paid-in Capital [Member]	Rights Offering [Member] AOCI Attributable to Parent [Member]	Rights Offering [Member] Retained Earnings [Member]	Rights Offering [Member]	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 common stock pursuant to warrant exercise (in shares)											7
Issuance of common stock pursuant to warrant exercise											$ 1	12			13
Stock-based compensation expense											0	3,720	0	0	3,720
Net loss											$ 0		0	(31,269)	(31,269)
Issuance of shares under employee stock purchase plan (in shares)											86
Issuance of shares under employee stock purchase plan											$ 0	372			372
Issuance of shares in Rights Offering, net of issuance costs of $111 (in shares)						7,317
Issuance of shares in Rights Offering, net of issuance costs of $111						$ 7	$ 14,882	$ 0	$ 0	$ 14,889
Balance (in shares) at Jun. 30, 2022											37,126
Balance at Jun. 30, 2022											$ 37	290,847	0	(267,469)	23,415
Balance (in shares) at Mar. 31, 2022											29,802
Balance at Mar. 31, 2022											$ 29	274,240	0	(253,473)	20,796
Issuance of common stock pursuant to warrant exercise (in shares)											7
Issuance of common stock pursuant to warrant exercise											$ 1	12			13
Stock-based compensation expense											0	1,713	0	0	1,713
Net loss											$ 0		0	(13,996)	(13,996)
Issuance of shares in Rights Offering, net of issuance costs of $111 (in shares)						7,317
Issuance of shares in Rights Offering, net of issuance costs of $111						$ 7	$ 14,882	$ 0	$ 0	$ 14,889
Balance (in shares) at Jun. 30, 2022											37,126
Balance at Jun. 30, 2022											$ 37	290,847	0	(267,469)	23,415
Balance (in shares) at Dec. 31, 2022											37,235
Balance at Dec. 31, 2022											$ 37	292,420	0	(294,705)	(2,248)
Issuance of common stock as part of debt extinguishment, net of issuance costs of $6 (in shares)	10,023
Issuance of common stock as part of debt extinguishment, net of issuance costs of $6	$ 10	$ 65,233	$ 0	$ 0	$ 65,243
Issuance of common stock pursuant to warrant exercise (in shares)											7,238
Issuance of common stock pursuant to warrant exercise											$ 7	14,820	0	0	14,827
Issuance of common stock upon exercise of stock options (in shares)											13
Issuance of common stock upon exercise of stock options											$ 0	58	0	0	58
Stock-based compensation expense											0	2,039	0	0	2,039
Net loss											$ 0	0	0	(19,711)	(19,711)
Issuance of shares under employee stock purchase plan (in shares)											262
Issuance of shares under employee stock purchase plan											$ 1	291	0	0	292
Balance (in shares) at Jun. 30, 2023											54,771
Balance at Jun. 30, 2023											$ 55	374,861	0	(314,416)	60,500
Balance (in shares) at Mar. 31, 2023											37,593
Balance at Mar. 31, 2023											$ 38	293,801	0	(304,506)	(10,667)
Issuance of common stock as part of debt extinguishment, net of issuance costs of $6 (in shares)	10,023
Issuance of common stock as part of debt extinguishment, net of issuance costs of $6	$ 10	$ 65,236	$ 0	$ 0	$ 65,246
Issuance of common stock pursuant to warrant exercise (in shares)											7,142
Issuance of common stock pursuant to warrant exercise											$ 7	14,623	0	0	14,630
Issuance of common stock upon exercise of stock options (in shares)											13
Issuance of common stock upon exercise of stock options											$ 0	58	0	0	58
Stock-based compensation expense											0	1,143	0	0	1,143
Net loss											$ 0	0	0	(9,910)	(9,910)
Balance (in shares) at Jun. 30, 2023											54,771
Balance at Jun. 30, 2023											$ 55	$ 374,861	$ 0	$ (314,416)	$ 60,500

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parentheticals) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2022
Rights Offering [Member]
Issuance cost	$ 111	$ 111

Note 1 - Description of the Bus

Note 1 - Description of the Business	6 Months Ended
	Jun. 30, 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 no

Note 2 - Summary of Significant

Note 2 - Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 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 six June 30, 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 three June 30, 2023, Stock-Based Compensation The Company's stock-based compensation programs include stock options and an employee stock purchase program. The Company accounts for stock-based compensation using the fair value method. The Company periodically issues stock options to officers, directors, employees and consultants for services rendered. Such issuances vest and expire according to terms established at the issuance date. Stock-based payments to officers, directors and employees, including grants of employee stock options, are recognized in the financial statements based on their grant date fair values, which are estimated using the Black-Scholes option-pricing model. Stock-based compensation expense is charged to operations on a straight-line basis over the vesting period. The Company has granted stock options with both time-based as well as performance-based vesting conditions. For stock awards with performance-based vesting conditions, the Company does not may The Company has also issued certain stock options with market-based vesting conditions. These vesting conditions relate to the achievement of certain market capitalization targets of the Company. The grant date fair value for these stock options was determined using a Monte Carlo simulation. The expense is recognized over the requisite service period for each tranche of the awards. The requisite service period is the service period derived from the Monte Carlo simulation model. If the market capitalization targets are met sooner than the derived service period, the Company will accelerate the recognition of stock-based compensation expense to reflect the cumulative expense associated with the vested shares. The Monte Carlo simulation requires the Company to make assumptions and judgements about the variables used in the calculation including the expected term, volatility of the Company's common stock, an assumed risk-free interest rate, and cost of equity. The assumptions used in the option-pricing model represent management’s best estimates. If factors change and different assumptions are used, the Company's stock-based compensation expense could be materially different in the future. See Note 6 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 June 30, 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 three June 30, 2023, Warranty accrual activity consisted of the following for the three six June 30, 2023 2022 Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 Beginning balance $ 50 $ 97 $ 50 $ 80 Add: Accruals for warranties issued during the period — 25 — 42 Less: Adjustment for inventory at cost (50 ) — (50 ) — Ending balance $ — $ 122 $ — $ 122 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: Six Months Ended June 30, 2023 2022 Common stock warrants — 7,310,917 Common stock options 6,888,015 5,608,140 Total 6,888,015 12,919,057 Recent Accounting Pronouncements There are no

Note 3 - Fair Value of Financia

Note 3 - Fair Value of Financial Instruments	6 Months Ended
	Jun. 30, 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 June 30, 2023 December 31, 2022 June 30, 2023 Assets Classification Level 1 Level 2 Level 3 Total Money market funds Cash and cash equivalents $ 56,388 $ — $ — $ 56,388 Total assets measured at fair value $ 56,388 $ — $ — $ 56,388 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 June 30, 2023 December 31, 2022

Note 4 - Balance Sheet Componen

Note 4 - Balance Sheet Components	6 Months Ended
	Jun. 30, 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): June 30, December 31, 2023 2022 Leasehold improvements $ 2,519 $ 2,519 Laboratory equipment 1,188 1,118 Furniture, fixtures and equipment 966 966 Software 296 289 Construction in progress 10 22 4,979 4,914 Less: Accumulated depreciation and amortization (3,224 ) (2,953 ) $ 1,755 $ 1,961 Depreciation expense was $0.1 million for the three June 30, 2023 2022 six June 30, 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): June 30, December 31, 2023 2022 Acquired patents and licenses $ 7,985 $ 7,985 Less: Accumulated amortization (5,767 ) (5,434 ) $ 2,218 $ 2,551 A schedule of the amortization of intangible assets for the remainder of 2023 three Years ending December 31: 2023 (remaining 6 months) $ 333 2024 665 2025 665 2026 555 $ 2,218 Accrued Expenses Accrued expenses consisted of the following (in thousands): June 30, December 31, 2023 2022 Compensation expense $ 2,123 $ 1,377 Director and officer liability insurance (Note 12) — 571 Clinical trial fees and costs 49 64 Professional fees 503 318 Warranty — 50 Other 169 215 $ 2,844 $ 2,595

Note 5 - Goodwill

Note 5 - Goodwill	6 Months Ended
	Jun. 30, 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 June 30, 2023 no

Note 6 - Stockholders' Equity a

Note 6 - Stockholders' Equity and Stock-based Compensation	6 Months Ended
	Jun. 30, 2023
Notes to Financial Statements
Share-Based Payment Arrangement [Text Block]	6. Equity and Stock-Based Compensation Private Placement Securities Purchase Agreement On April 30, 2023, May 9, 2023, 2022 8 Rights Offering On June 9, 2022, “2022 one one “2022 one 2022 2022 2022 May 2023, June 16, 2023, 2022 Common Stock Warrants 2022 At-the-Market Equity Offering On February 4, 2021, may 415 1933, no not six June 30, 2023 2022, Common Stock Warrants In connection with the 2022 2022 2022 not may not three May 10, 2023, May 9, 2023 June 16, 2023. June 30, 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 June 30, 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, June 30, 2023 A summary of stock option activity under the 2015 2017 six June 30, 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 2,242,386 5.12 Options exercised (12,900 ) 4.55 Options canceled (165,394 ) 6.59 Options expired (426,773 ) 13.01 Balances — June 30, 2023 6,888,015 $ 10.35 7.40 Exercisable — June 30, 2023 3,589,647 $ 14.23 5.58 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 six June 30, 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 442,386 5.93 Options exercised (12,900 ) 4.55 Options canceled (127,894 ) 7.92 Options expired (348,601 ) 13.05 Balances — June 30, 2023 4,683,385 $ 12.44 6.48 Exercisable — June 30, 2023 3,372,083 $ 14.47 5.52 The fair value of the time-based options granted during the six June 30, 2023 Performance-based 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-based option activity under the 2017 six June 30, 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 800,000 3.03 Options exercised — — Options canceled (37,500 ) 2.05 Options expired (78,172 ) 12.84 Balances — June 30, 2023 1,204,630 $ 5.47 8.93 Exercisable — June 30, 2023 217,564 $ 10.55 6.47 The fair value of the performance-based options granted during the six June 30, 2023 Market-based Options Certain stock options awarded by the Company contain market conditions related to achievement of certain market capitalization targets. The options will vest and become exercisable once the specific market capitalization targets are fulfilled. A summary of the market-based option activity under the 2017 six June 30, 2023 Stock Options Outstanding Number of shares Weighted average exercise price Weighted average remaining life (in years) Balances — December 31, 2022 — $ — — Options granted 1,000,000 6.44 Options exercised — — Options canceled — — Options expired — — Balances — June 30, 2023 1,000,000 $ 6.44 9.83 Exercisable — June 30, 2023 — — — The fair value of the market-based options granted during the six June 30, 2023 The Company estimates the fair value of time-based and performance-based stock options on the grant date using the Black-Scholes option pricing model. The estimated fair value of these 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 time-based and performance-based stock options was estimated using the following weighted-average assumptions: Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 Expected term in years 5.0 - 6.3 5.3 - 6.3 5.0 - 6.3 5.3 - 6.8 Expected volatility 89% - 94% 88% 89% - 94% 83% - 88% Risk-free interest rate 3.8% 3.0% 3.8% 1.9% - 3.0% Dividend yield — — — — The Company estimates the fair value of market-based stock options on the grant date using a Monte Carlo simulation model. The estimated fair value of these employee stock options is amortized over the requisite service period for each tranche of the awards. The requisite service period is the service period derived from the Monte Carlo simulation model. If the market capitalization targets are met sooner than the derived service period, the Company will accelerate the recognition of stock-based compensation expense to reflect the cumulative expense associated with the vested shares. The fair value of market-based stock options was estimated using the following weighted-average assumptions: Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 Expected term in years 4.4 - 5.9 — 4.4 - 5.9 — Expected volatility 90% — 90% — Risk-free interest rate 3.4% — 3.4% — 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 June 30, 2023, not 2017 six June 30, 2023, 2017 June 30, 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 June 30, Six Months Ended June 30, 2023 2022 2023 2022 Expected term in years 0.5 - 1.0 0.5 - 1.0 0.5 - 1.0 0.5 - 1.0 Expected volatility 83% 83% 83% 83% Risk-free interest rate 5.1% - 5.2% 0.6% - 0.9% 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 June 30, Six Months Ended June 30, 2023 2022 2023 2022 Cost of revenues $ — $ 90 $ — $ 180 Research and development 518 496 776 953 Sales and marketing — 362 — 816 General and administrative 625 765 1,263 1,771 Total stock-based compensation expense $ 1,143 $ 1,713 $ 2,039 $ 3,720 As of June 30, 2023 not Total stock-based compensation expense by type was as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 Time-based options $ 876 $ 1,445 $ 1,554 $ 3,252 Performance-based and market-based options 245 132 362 215 ESPP 22 136 123 253 Total stock-based compensation expense $ 1,143 $ 1,713 $ 2,039 $ 3,720

Note 7 - Research Grants and Ag

Note 7 - Research Grants and Agreements	6 Months Ended
	Jun. 30, 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 six June 30, 2023 not three six June 30, 2022 June 30, 2023 not

Note 8 - Commitments and Contin

Note 8 - Commitments and Contingencies	6 Months Ended
	Jun. 30, 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. six June 30, 2023 2022 April 30, 2023, 2022 April 30, 2023. May 9, 2023 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): June 30, December 31, Assets: 2023 2022 Right-of-use assets $ 7,670 $ 8,062 June 30, December 31, Liabilities: 2023 2022 Current operating lease liabilities $ 975 $ 896 Non-current operating lease liabilities 8,644 9,144 Total lease liabilities $ 9,619 $ 10,040 Total cash paid for operating lease liabilities (in thousands): Six Months Ended June 30, 2023 2022 Cash paid for operating lease liabilities $ 907 $ 894 Maturities of operating lease liabilities were as follows (in thousands): Year ending December 31: 2023 (remaining 6 months) $ 937 2024 1,910 2025 1,977 2026 2,046 2027 2,117 Thereafter 4,075 Total lease payments 13,062 Less imputed interest (3,443 ) Total lease liabilities $ 9,619 Weighted-average remaining lease term and discount rate, as of June 30, 2023 Weighted-average remaining lease term 6.34 Weighted-average discount rate 10 % Rent expense, including common area maintenance charges, was approximately $0.5 million for each of the three June 30, 2023 2022 six June 30, 2023 2022 Legal Proceedings From time to time, we may may In November 2022, not not March 2023, one not not not

Note 9 - Controlled Launch

Note 9 - Controlled Launch	6 Months Ended
	Jun. 30, 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 six June 30, 2023 three six June 30, 2022 In September 2022, fourth 2022 During the six June 30, 2023 not three six June 30, 2022 three six June 30, 2022 10

Note 10 - Revenue

Note 10 - Revenue	6 Months Ended
	Jun. 30, 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, not three six June 30, 2023 three six June 30, 2022 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, 9

Note 11 - Segment Reporting

Note 11 - Segment Reporting	6 Months Ended
	Jun. 30, 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. 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 June 30, Six Months Ended June 30, 2023 2022 2023 2022 Systems $ — $ 209 $ — $ 576 Cycle units — 56 — 133 Total consolidated revenue $ — $ 265 $ — $ 709 Revenue by geography consisted of the following (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 North America $ — $ 214 $ — $ 526 Rest of World — 51 — 183 Total consolidated revenue $ — $ 265 $ — $ 709

Note 12 - Related Party Transac

Note 12 - Related Party Transactions	6 Months Ended
	Jun. 30, 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 June 30, 2023 On September 20, 2022, 2022 April 30, 2023, 2022 April 30, 2023. 2022 No 2022 8

Note 13 - Restructuring Charges

Note 13 - Restructuring Charges	6 Months Ended
	Jun. 30, 2023
Notes to Financial Statements
Restructuring and Related Activities Disclosure [Text Block]	13. Restructuring Charges On March 31, 2022, March 31, 2022. March 2022 six June 30, 2022. In February 2023, seven February 2023 six June 30, 2023.

Significant Accounting Policies

Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 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 six June 30, 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
Share-Based Payment Arrangement [Policy Text Block]	Stock-Based Compensation The Company's stock-based compensation programs include stock options and an employee stock purchase program. The Company accounts for stock-based compensation using the fair value method. The Company periodically issues stock options to officers, directors, employees and consultants for services rendered. Such issuances vest and expire according to terms established at the issuance date. Stock-based payments to officers, directors and employees, including grants of employee stock options, are recognized in the financial statements based on their grant date fair values, which are estimated using the Black-Scholes option-pricing model. Stock-based compensation expense is charged to operations on a straight-line basis over the vesting period. The Company has granted stock options with both time-based as well as performance-based vesting conditions. For stock awards with performance-based vesting conditions, the Company does not may The Company has also issued certain stock options with market-based vesting conditions. These vesting conditions relate to the achievement of certain market capitalization targets of the Company. The grant date fair value for these stock options was determined using a Monte Carlo simulation. The expense is recognized over the requisite service period for each tranche of the awards. The requisite service period is the service period derived from the Monte Carlo simulation model. If the market capitalization targets are met sooner than the derived service period, the Company will accelerate the recognition of stock-based compensation expense to reflect the cumulative expense associated with the vested shares. The Monte Carlo simulation requires the Company to make assumptions and judgements about the variables used in the calculation including the expected term, volatility of the Company's common stock, an assumed risk-free interest rate, and cost of equity. The assumptions used in the option-pricing model represent management’s best estimates. If factors change and different assumptions are used, the Company's stock-based compensation expense could be materially different in the future. See Note 6
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 June 30, 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 three June 30, 2023, Warranty accrual activity consisted of the following for the three six June 30, 2023 2022 Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 Beginning balance $ 50 $ 97 $ 50 $ 80 Add: Accruals for warranties issued during the period — 25 — 42 Less: Adjustment for inventory at cost (50 ) — (50 ) — Ending balance $ — $ 122 $ — $ 122
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: Six Months Ended June 30, 2023 2022 Common stock warrants — 7,310,917 Common stock options 6,888,015 5,608,140 Total 6,888,015 12,919,057
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)	6 Months Ended
	Jun. 30, 2023
Notes Tables
Schedule of Product Warranty Liability [Table Text Block]	Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 Beginning balance $ 50 $ 97 $ 50 $ 80 Add: Accruals for warranties issued during the period — 25 — 42 Less: Adjustment for inventory at cost (50 ) — (50 ) — Ending balance $ — $ 122 $ — $ 122
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	Six Months Ended June 30, 2023 2022 Common stock warrants — 7,310,917 Common stock options 6,888,015 5,608,140 Total 6,888,015 12,919,057

Note 3 - Fair Value of Financ_2

Note 3 - Fair Value of Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2023
Notes Tables
Fair Value, Assets Measured on Recurring Basis [Table Text Block]	June 30, 2023 Assets Classification Level 1 Level 2 Level 3 Total Money market funds Cash and cash equivalents $ 56,388 $ — $ — $ 56,388 Total assets measured at fair value $ 56,388 $ — $ — $ 56,388 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)	6 Months Ended
	Jun. 30, 2023
Notes Tables
Property, Plant and Equipment [Table Text Block]	June 30, December 31, 2023 2022 Leasehold improvements $ 2,519 $ 2,519 Laboratory equipment 1,188 1,118 Furniture, fixtures and equipment 966 966 Software 296 289 Construction in progress 10 22 4,979 4,914 Less: Accumulated depreciation and amortization (3,224 ) (2,953 ) $ 1,755 $ 1,961
Schedule of Finite-Lived Intangible Assets [Table Text Block]	June 30, December 31, 2023 2022 Acquired patents and licenses $ 7,985 $ 7,985 Less: Accumulated amortization (5,767 ) (5,434 ) $ 2,218 $ 2,551
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	Years ending December 31: 2023 (remaining 6 months) $ 333 2024 665 2025 665 2026 555 $ 2,218
Schedule of Accrued Liabilities [Table Text Block]	June 30, December 31, 2023 2022 Compensation expense $ 2,123 $ 1,377 Director and officer liability insurance (Note 12) — 571 Clinical trial fees and costs 49 64 Professional fees 503 318 Warranty — 50 Other 169 215 $ 2,844 $ 2,595

Note 6 - Stockholders' Equity_2

Note 6 - Stockholders' Equity and Stock-based Compensation (Tables)	6 Months Ended
	Jun. 30, 2023
Notes Tables
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]	Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 Cost of revenues $ — $ 90 $ — $ 180 Research and development 518 496 776 953 Sales and marketing — 362 — 816 General and administrative 625 765 1,263 1,771 Total stock-based compensation expense $ 1,143 $ 1,713 $ 2,039 $ 3,720
Share-Based Payment Arrangement, Cost by Plan [Table Text Block]	Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 Time-based options $ 876 $ 1,445 $ 1,554 $ 3,252 Performance-based and market-based options 245 132 362 215 ESPP 22 136 123 253 Total stock-based compensation expense $ 1,143 $ 1,713 $ 2,039 $ 3,720
Share-Based Payment Arrangement, Option [Member]
Notes Tables
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 Expected term in years 5.0 - 6.3 5.3 - 6.3 5.0 - 6.3 5.3 - 6.8 Expected volatility 89% - 94% 88% 89% - 94% 83% - 88% Risk-free interest rate 3.8% 3.0% 3.8% 1.9% - 3.0% Dividend yield — — — — Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 Expected term in years 4.4 - 5.9 — 4.4 - 5.9 — Expected volatility 90% — 90% — Risk-free interest rate 3.4% — 3.4% — Dividend yield — — — —
Market-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 — $ — — Options granted 1,000,000 6.44 Options exercised — — Options canceled — — Options expired — — Balances — June 30, 2023 1,000,000 $ 6.44 9.83 Exercisable — June 30, 2023 — — —
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 800,000 3.03 Options exercised — — Options canceled (37,500 ) 2.05 Options expired (78,172 ) 12.84 Balances — June 30, 2023 1,204,630 $ 5.47 8.93 Exercisable — June 30, 2023 217,564 $ 10.55 6.47
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 442,386 5.93 Options exercised (12,900 ) 4.55 Options canceled (127,894 ) 7.92 Options expired (348,601 ) 13.05 Balances — June 30, 2023 4,683,385 $ 12.44 6.48 Exercisable — June 30, 2023 3,372,083 $ 14.47 5.52
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 June 30, Six Months Ended June 30, 2023 2022 2023 2022 Expected term in years 0.5 - 1.0 0.5 - 1.0 0.5 - 1.0 0.5 - 1.0 Expected volatility 83% 83% 83% 83% Risk-free interest rate 5.1% - 5.2% 0.6% - 0.9% 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 2,242,386 5.12 Options exercised (12,900 ) 4.55 Options canceled (165,394 ) 6.59 Options expired (426,773 ) 13.01 Balances — June 30, 2023 6,888,015 $ 10.35 7.40 Exercisable — June 30, 2023 3,589,647 $ 14.23 5.58

Note 8 - Commitments and Cont_2

Note 8 - Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2023
Notes Tables
Schedule of Information Related to Right-of-use Assets and Lease Liabilities [Table Text Block]	June 30, December 31, Assets: 2023 2022 Right-of-use assets $ 7,670 $ 8,062 June 30, December 31, Liabilities: 2023 2022 Current operating lease liabilities $ 975 $ 896 Non-current operating lease liabilities 8,644 9,144 Total lease liabilities $ 9,619 $ 10,040 Six Months Ended June 30, 2023 2022 Cash paid for operating lease liabilities $ 907 $ 894 Year ending December 31: 2023 (remaining 6 months) $ 937 2024 1,910 2025 1,977 2026 2,046 2027 2,117 Thereafter 4,075 Total lease payments 13,062 Less imputed interest (3,443 ) Total lease liabilities $ 9,619 Weighted-average remaining lease term 6.34 Weighted-average discount rate 10 %

Note 11 - Segment Reporting (Ta

Note 11 - Segment Reporting (Tables)	6 Months Ended
	Jun. 30, 2023
Notes Tables
Disaggregation of Revenue [Table Text Block]	Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 Systems $ — $ 209 $ — $ 576 Cycle units — 56 — 133 Total consolidated revenue $ — $ 265 $ — $ 709
Revenue from External Customers by Geographic Areas [Table Text Block]	Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 North America $ — $ 214 $ — $ 526 Rest of World — 51 — 183 Total consolidated revenue $ — $ 265 $ — $ 709

Note 2 - Summary of Significa_3

Note 2 - Summary of Significant Accounting Policies - Warrant Accrual Activity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Beginning balance	$ 50	$ 97	$ 50	$ 80
Add: Accruals for warranties issued during the period	0	25	0	42
Less: Adjustment for inventory at cost	(50)	0	(50)	0
Ending balance	$ 0	$ 122	$ 0	$ 122

Note 2 - Summary of Significa_4

Note 2 - Summary of Significant Accounting Policies - Antidilutive Securities (Details) - shares	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Antidilutive securities (in shares)	6,888,015	12,919,057
Warrant [Member]
Antidilutive securities (in shares)	0	7,310,917
Share-Based Payment Arrangement, Option [Member]
Antidilutive securities (in shares)	6,888,015	5,608,140

Note 3 - Fair Value of Financ_3

Note 3 - Fair Value of Financial Instruments (Details Textual) - USD ($) $ in Thousands	Jun. 30, 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	Jun. 30, 2023	Dec. 31, 2022
Total assets measured at fair value	$ 56,388	$ 57,973
Total assets measured at fair value	(56,388)	(57,973)
Fair Value, Inputs, Level 1 [Member]
Total assets measured at fair value	56,388	57,973
Total assets measured at fair value	(56,388)	(57,973)
Fair Value, Inputs, Level 2 [Member]
Total assets measured at fair value	0	0
Total assets measured at fair value	0	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	56,388	57,973
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Cash and Cash equivalents	56,388	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		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Depreciation	$ 100	$ 100	$ 271	$ 347
Finite-Lived Intangible Asset, Useful Life (Year)	12 years		12 years

Note 4 - Balance Sheet Compon_4

Note 4 - Balance Sheet Components - Property and Equipment, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Property and equipment, gross	$ 4,979	$ 4,914
Less: Accumulated depreciation and amortization	(3,224)	(2,953)
Property and equipment, net	1,755	1,961
Leasehold Improvements [Member]
Property and equipment, gross	2,519	2,519
Laboratory Equipment [Member]
Property and equipment, gross	1,188	1,118
Furniture and Fixtures [Member]
Property and equipment, gross	966	966
Software and Software Development Costs [Member]
Property and equipment, gross	296	289
Construction in Progress [Member]
Property and equipment, gross	$ 10	$ 22

Note 4 - Balance Sheet Compon_5

Note 4 - Balance Sheet Components - Intangible Assets, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Less: Accumulated amortization	$ (5,767)	$ (5,434)
Finite-Lived Intangible Assets, Net	2,218	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	Jun. 30, 2023	Dec. 31, 2022
2023 (remaining 6 months)	$ 333
2024	665
2025	665
2026	555
Finite-Lived Intangible Assets, Net	$ 2,218	$ 2,551

Note 4 - Balance Sheet Compon_7

Note 4 - Balance Sheet Components - Accrued Expenses (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Compensation expense	$ 2,123		$ 1,377
Director and officer liability insurance (Note 12)	0		571
Clinical trial fees and costs	49		64
Professional fees	503		318
Warranty	0	$ 50	50	$ 122	$ 97	$ 80
Other	169		215
Accrued Liabilities, Current	$ 2,844		$ 2,595

Note 5 - Goodwill (Details Text

Note 5 - Goodwill (Details Textual) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 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

6 Months Ended

12 Months Ended

Apr. 30, 2023

Jan. 01, 2023

Jun. 09, 2022

May 31, 2021

Nov. 30, 2017

Jun. 30, 2023

Jun. 30, 2023

Jun. 15, 2023

Jun. 30, 2022

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

$ 0.001

Proceeds from Issuance of Common Stock

$ 0

$ 14,963

Proceeds from Warrant Exercises

14,835

$ 0

Time-based Options [Member]

Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Intrinsic Value

$ 2,000

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

$ 1,900

Market-based Options [Member]

Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Intrinsic Value

$ 4,800

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)

1,740,008

1,740,008

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)

1,244,626

1,244,626

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 Inducement Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member] | Maximum [Member]

Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period (Year)

10 years

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

198,529

Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares)

0

262,470

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, Exercise Price of Warrants or Rights (in dollars per share)

$ 2.05

$ 2.05

$ 2.05

Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)

7,317,072

7,317,072

Class of Warrants or Rights, Redemption Price Per Share (in dollars per share)

$ 0.01

$ 0.01

Class of Warrant or Right, Period of Written Notice for Exercise (Day)

30 days

Class of Warrant or Right, Percentage Required for Redemption

200%

200%

Class of Warrant or Right, Exercise, Consecutive Trading Days (Day)

20 days

Class of Warrant or Right, Exercised During Period (in shares)

66,175

7,250,897

Proceeds from Warrant Exercises

$ 14,900

Class of Warrant or Right, Outstanding (in shares)

0

0

Loan Agreement [Member]

Debt Instrument, Decrease, Forgiveness

$ 65,000

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

Rights Offering [Member]

Stock Issued During Period, Shares, New Issues (in shares)

7,317,072

Common Stock, Par or Stated Value Per Share (in dollars per share)

$ 0.001

Shares Issued, Price Per Share (in dollars per share)

$ 2.05

Equity Offering, Units, Sale of Units (in shares)

7,317,072

Number of Shares Per Unit Issued (in shares)

1

Number of Warrants Per Unit (in shares)

1

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

Class of Warrants or Rights, Redemption Price Per Share (in dollars per share)

$ 0.01

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]	6 Months Ended	12 Months Ended
	Jun. 30, 2023 $ / shares shares	Dec. 31, 2022 $ / shares shares
Options balances, number of shares (in shares) | shares	5,250,696
Options balances, weighted average exercise price (in dollars per share) | $ / shares	$ 12.67
Options balances, weighted average remaining life (Year)	7 years 4 months 24 days	6 years 2 months 26 days
Options granted, number of shares (in shares) | shares	2,242,386
Options granted, weighted average exercise price (in dollars per share) | $ / shares	$ 5.12
Options exercised, number of shares (in shares) | shares	(12,900)
Options exercised, weighted average exercise price (in dollars per share) | $ / shares	$ 4.55
Options canceled, number of shares (in shares) | shares	(165,394)
Options canceled, weighted average exercise price (in dollars per share) | $ / shares	$ 6.59
Options expired, number of shares (in shares) | shares	(426,773)
Options expired, weighted average exercise price (in dollars per share) | $ / shares	$ 13.01
Options balances, number of shares (in shares) | shares	6,888,015	5,250,696
Options balances, weighted average exercise price (in dollars per share) | $ / shares	$ 10.35	$ 12.67
Options exercisable, number of shares (in shares) | shares	3,589,647
Options exercisable, weighted average exercise price (in dollars per share) | $ / shares	$ 14.23
Options exercisable, weighted average remaining life (Year)	5 years 6 months 29 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]	6 Months Ended	12 Months Ended
	Jun. 30, 2023 $ / shares shares	Dec. 31, 2022 $ / shares shares
Options balances, number of shares (in shares) | shares	4,730,394
Options balances, weighted average exercise price (in dollars per share) | $ / shares	$ 12.95
Options balances, weighted average remaining life (Year)	6 years 5 months 23 days	6 years 1 month 28 days
Options granted, number of shares (in shares) | shares	442,386
Options granted, weighted average exercise price (in dollars per share) | $ / shares	$ 5.93
Options exercised, number of shares (in shares) | shares	(12,900)
Options exercised, weighted average exercise price (in dollars per share) | $ / shares	$ 4.55
Options canceled, number of shares (in shares) | shares	(127,894)
Options canceled, weighted average exercise price (in dollars per share) | $ / shares	$ 7.92
Options expired, number of shares (in shares) | shares	(348,601)
Options expired, weighted average exercise price (in dollars per share) | $ / shares	$ 13.05
Options balances, number of shares (in shares) | shares	4,683,385	4,730,394
Options balances, weighted average exercise price (in dollars per share) | $ / shares	$ 12.44	$ 12.95
Options exercisable, number of shares (in shares) | shares	3,372,083
Options exercisable, weighted average exercise price (in dollars per share) | $ / shares	$ 14.47
Options exercisable, weighted average remaining life (Year)	5 years 6 months 7 days

Note 6 - Stockholders' Equity_6

Note 6 - Stockholders' Equity and Stock-based Compensation - Summary of Performance Option Activity (Details) - Performance Options [Member]	6 Months Ended	12 Months Ended
	Jun. 30, 2023 $ / shares shares	Dec. 31, 2022 $ / shares shares
Options balances, number of shares (in shares) | shares	520,302
Options balances, weighted average exercise price (in dollars per share) | $ / shares	$ 10.08
Options balances, weighted average remaining life (Year)	8 years 11 months 4 days	7 years 7 days
Options granted, number of shares (in shares) | shares	800,000
Options granted, weighted average exercise price (in dollars per share) | $ / shares	$ 3.03
Options exercised, number of shares (in shares) | shares	0
Options exercised, weighted average exercise price (in dollars per share) | $ / shares	$ 0
Options canceled, number of shares (in shares) | shares	(37,500)
Options canceled, weighted average exercise price (in dollars per share) | $ / shares	$ 2.05
Options expired, number of shares (in shares) | shares	(78,172)
Options expired, weighted average exercise price (in dollars per share) | $ / shares	$ 12.84
Options balances, number of shares (in shares) | shares	1,204,630	520,302
Options balances, weighted average exercise price (in dollars per share) | $ / shares	$ 5.47	$ 10.08
Options exercisable, number of shares (in shares) | shares	217,564
Options exercisable, weighted average exercise price (in dollars per share) | $ / shares	$ 10.55
Options exercisable, weighted average remaining life (Year)	6 years 5 months 19 days

Note 6 - Stockholders' Equity_7

Note 6 - Stockholders' Equity and Stock-based Compensation - Summary of Market-based Option Activity (Details) - Market-based Options [Member] - $ / shares	6 Months Ended
	Jun. 30, 2023
Options balances, number of shares (in shares)	0
Options balances, weighted average exercise price (in dollars per share)	$ 0
Options granted, number of shares (in shares)	1,000,000
Options granted, weighted average exercise price (in dollars per share)	$ 6.44
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)	0
Options expired, weighted average exercise price (in dollars per share)	$ 0
Options balances, number of shares (in shares)	1,000,000
Options balances, weighted average exercise price (in dollars per share)	$ 6.44
Options balances, weighted average remaining life (Year)	9 years 9 months 29 days
Options exercisable, number of shares (in shares)	0
Options exercisable, weighted average exercise price (in dollars per share)	$ 0

Note 6 - Stockholders' Equity_8

Note 6 - Stockholders' Equity and Stock-based Compensation - Option Assumptions (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Market-based Options [Member]
Expected volatility	90%	0%	90%	0%
Risk-free interest rate	3.40%	0%	3.40%	0%
Dividend yield	0%	0%	0%	0%
Time-based and Performance Options [Member]
Expected volatility		88%
Risk-free interest rate	3.80%	3%	3.80%
Dividend yield	0%	0%	0%	0%
Minimum [Member] | Market-based Options [Member]
Expected term in years (Year)	4 years 4 months 24 days		4 years 4 months 24 days
Minimum [Member] | Time-based and Performance Options [Member]
Expected term in years (Year)	5 years	5 years 3 months 18 days	5 years	5 years 3 months 18 days
Expected volatility	89%		89%	83%
Risk-free interest rate				1.90%
Maximum [Member] | Market-based Options [Member]
Expected term in years (Year)	5 years 10 months 24 days		5 years 10 months 24 days
Maximum [Member] | Time-based and Performance Options [Member]
Expected term in years (Year)	6 years 3 months 18 days	6 years 3 months 18 days	6 years 3 months 18 days	6 years 9 months 18 days
Expected volatility	94%		94%	88%
Risk-free interest rate				3%

Note 6 - Stockholders' Equity_9

Note 6 - Stockholders' Equity and Stock-based Compensation - ESPP Assumptions (Details) - The 2017 Employee Stock Purchase Plan [Member]	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Expected volatility	83%	83%	83%	83%
Dividend yield	0%	0%	0%	0%
Minimum [Member]
Expected term in years (Year)	6 months	6 months	6 months	6 months
Risk-free interest rate	5.10%	0.60%	5.10%	0.60%
Maximum [Member]
Expected term in years (Year)	1 year	1 year	1 year	1 year
Risk-free interest rate	5.20%	0.90%	5.20%	0.90%

Note 6 - Stockholders' Equit_10

Note 6 - Stockholders' Equity and Stock-based Compensation - Stock-based Compensation Expense by Recorded Location (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2023	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Total stock-based compensation expense	$ 1,143	$ 1,143	$ 1,713	$ 2,039	$ 3,720
Cost of Sales [Member]
Total stock-based compensation expense		0	90	0	180
Research and Development Expense [Member]
Total stock-based compensation expense		518	496	776	953
Selling and Marketing Expense [Member]
Total stock-based compensation expense		0	362	0	816
General and Administrative Expense [Member]
Total stock-based compensation expense		$ 625	$ 765	$ 1,263	$ 1,771

Note 6 - Stockholders' Equit_11

Note 6 - Stockholders' Equity and Stock-based Compensation - Stock-based Compensation Expense by Type (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2023	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Total stock-based compensation expense	$ 1,143	$ 1,143	$ 1,713	$ 2,039	$ 3,720
Time-based Options [Member]
Total stock-based compensation expense	876		1,445	1,554	3,252
Performance-based and Market-based Options [Member]
Total stock-based compensation expense	245		132	362	215
Employee Stock Purchase Plan Award [Member]
Total stock-based compensation expense	$ 22		$ 136	$ 123	$ 253

Note 7 - Research Grants and _2

Note 7 - Research Grants and Agreements (Details Textual) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		6 Months Ended
	May 31, 2021	Mar. 31, 2021	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Research and Development Expense			$ 6,697	$ 5,458	$ 12,526	$ 12,227
Old Dominion University Research Foundation [Member] | Sponsored Research Agreement SRA [Member]
Research and Development Expense			$ 0	$ 100	$ 0	$ 200
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		6 Months Ended
	Apr. 30, 2023 USD ($) $ / shares shares	Jun. 30, 2023 USD ($) $ / shares	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) $ / shares	Jun. 30, 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		$ 0.001
Operating Lease, Expense		$ 0.5	$ 0.5	$ 1	$ 1
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] | 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				1.7
Interest Expense				$ 1.1
Loan Agreement [Member]
Debt Instrument, Decrease, Forgiveness	$ 65
Interest Payable	$ 0.2

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	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Right-of-use assets	$ 7,670		$ 8,062
Current operating lease liabilities	975		896
Non-current operating lease liabilities	8,644		9,144
Total lease liabilities	9,619		$ 10,040
Cash paid for operating lease liabilities	907	$ 894
2023 (remaining 6 months)	937
2024	1,910
2025	1,977
2026	2,046
2027	2,117
Thereafter	4,075
Total lease payments	13,062
Less imputed interest	$ (3,443)
Weighted-average remaining lease term (Year)	6 years 4 months 2 days
Weighted-average discount rate	10%

Note 9 - Controlled Launch (Det

Note 9 - Controlled Launch (Details Textual) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Feb. 28, 2021
Number of KOLs					70
Controlled Launch, Program Expenses	$ 0	$ 100	$ 0	$ 600
Revenue from Contract with Customer, Excluding Assessed Tax	$ 0	265	0	709
Redemption of Non Cash Credits [Member]
Revenue from Contract with Customer, Excluding Assessed Tax		$ 100	$ 0	$ 400
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		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenue from Contract with Customer, Excluding Assessed Tax	$ 0	$ 265	$ 0	$ 709
Redemption of Non Cash Credits [Member]
Revenue from Contract with Customer, Excluding Assessed Tax		$ 100	$ 0	$ 400

Note 11 - Segment Reporting (De

Note 11 - Segment Reporting (Details Textual)	6 Months Ended
	Jun. 30, 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		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Total revenues	$ 0	$ 265	$ 0	$ 709
System Products [Member]
Total revenues	0	209	0	576
Cycle Units Products [Member]
Total revenues	$ 0	$ 56	$ 0	$ 133

Note 11 - Segment Reporting -_2

Note 11 - Segment Reporting - Revenue by Geography (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Total revenues	$ 0	$ 265	$ 0	$ 709
North America [Member]
Total revenues	0	214	0	526
Rest of World [Member]
Total revenues	$ 0	$ 51	$ 0	$ 183

Note 12 - Related Party Trans_2

Note 12 - Related Party Transactions (Details Textual) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended
	May 31, 2023	Apr. 30, 2023	Sep. 20, 2022	Mar. 31, 2023	Jun. 30, 2023	Dec. 31, 2022
Accrued Liabilities, Current					$ 2,844	$ 2,595
Common Stock, Par or Stated Value Per Share (in dollars per share)					$ 0.001	$ 0.001
Loan Agreement [Member]
Debt Instrument, Decrease, Forgiveness		$ 65,000
Interest Payable		$ 200
Robert W. Duggan [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
Related Party Transaction, Amounts of Transaction	$ 1,000		$ 65,000
Accrued Liabilities, Current					$ 0

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