Avinger (AVGR) 10-Q 10 May 22 2022 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2022	May 06, 2022
Document Information [Line Items]
Entity Central Index Key	0001506928
Entity Registrant Name	Avinger Inc
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2022
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2022
Document Transition Report	false
Entity File Number	001-36817
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-8873453
Entity Address, Address Line One	400 Chesapeake Drive
Entity Address, City or Town	Redwood City
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94063
City Area Code	650
Local Phone Number	241-7900
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	AVGR
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		5,679,849

Condensed Balance Sheets (Curre

Condensed Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 20,006	$ 19,497
Accounts receivable, net of allowance for doubtful accounts of $6 at March 31, 2022 and December 31, 2021	1,365	1,393
Inventories	5,350	4,601
Prepaid expenses and other current assets	1,315	300
Total current assets	28,036	25,791
Right of use asset	2,940	3,179
Property and equipment, net	230	95
Other assets	406	420
Total assets	31,612	29,485
Current liabilities:
Accounts payable	1,172	1,394
Accrued compensation	1,881	1,609
Series A preferred stock dividends payable	1,127	0
Accrued expenses and other current liabilities	816	718
Leasehold liability, current portion	1,011	985
Total current liabilities	6,007	4,706
Borrowings, long-term portion	12,727	12,287
Leasehold liability, long-term portion	1,929	2,194
Other long-term liabilities	719	575
Total liabilities	21,382	19,762
Commitments and contingencies (Note 6)
Stockholders’ equity:
Convertible preferred stock issuable in series, par value of $0.001 Shares authorized: 5,000,000 at March 31, 2022 and December 31, 2021 Shares issued and outstanding: 58,851 and 56,451 at March 31, 2022 and December 31, 2021, respectively; aggregate liquidation preference of $56,366 at March 31, 2022 and December 31, 2021	0	0
Common stock, par value of $0.001; Shares authorized: 100,000,000 at March 31, 2022 and December 31, 2021 Shares issued and outstanding: 5,454,849 and 4,778,263 at March 31, 2022 and December 31, 2021, respectively	5	96
Additional paid-in capital	400,118	394,380
Accumulated deficit	(389,893)	(384,753)
Total stockholders’ equity	10,230	9,723
Total liabilities and stockholders’ equity	$ 31,612	$ 29,485

Condensed Balance Sheets (Cur_2

Condensed Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Accounts receivable, allowance for doubtful accounts	$ 6	$ 6
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	58,851	56,451
Preferred stock, shares outstanding (in shares)	58,851	56,451
Preferred stock, liquidation preference	$ 56,366	$ 56,366
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	5,454,849	4,778,263
Common stock, shares outstanding (in shares)	5,454,849	4,778,263

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenues	$ 1,888	$ 2,559
Cost of revenues	1,364	1,665
Gross profit	524	894
Operating expenses:
Research and development	1,072	1,598
Selling, general and administrative	4,148	3,945
Total operating expenses	5,220	5,543
Loss from operations	(4,696)	(4,649)
Interest expense, net	(439)	(396)
Other expense, net	(5)	(7)
Net loss and comprehensive loss	(5,140)	(5,052)
Accretion of preferred stock dividends	(1,127)	(1,044)
Deemed dividend arising from beneficial conversion feature of convertible preferred stock	(5,111)	0
Net loss applicable to common stockholders	$ (11,378)	$ (6,096)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (2.33)	$ (1.33)
Weighted average common shares used to compute net loss per share, basic and diluted (in shares)	4,889	4,572

Condensed Statements of Stockho

Condensed Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Series D Preferred Stock [Member]Preferred Stock [Member]	Series D Preferred Stock [Member]Common Stock [Member]	Series D Preferred Stock [Member]Additional Paid-in Capital [Member]	Series D Preferred Stock [Member]Retained Earnings [Member]	Series D Preferred Stock [Member]	Series B Preferred Stock [Member]Preferred Stock [Member]	Series B Preferred Stock [Member]Common Stock [Member]	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Dec. 31, 2020								52,369	4,246,306
Balance at Dec. 31, 2020								$ 0	$ 85	$ 380,332	$ (367,341)	$ 13,076
Issuance of common stock in public offerings, net of commissions and issuance costs (in shares)								0	500,000
Issuance of common stock in public offerings, net of commissions and issuance costs								$ 0	$ 10	13,067	0	13,077
Conversion of Series B preferred stock into common stock (in shares)						(93)	18,600
Issuance of common stock under officers and directors purchase plan and vesting of restricted stock units (in shares)								0	2,669
Employee stock-based compensation								$ 0	$ 0	418	0	418
Accretion of Series A preferred stock dividends								0	0	(1,044)	0	(1,044)
Net and comprehensive loss								$ 0	$ 0	0	(5,052)	(5,052)
Balance (in shares) at Mar. 31, 2021								52,276	4,767,575
Balance at Mar. 31, 2021								$ 0	$ 95	392,773	(372,393)	20,475
Balance (in shares) at Dec. 31, 2021								56,451	4,778,263
Balance at Dec. 31, 2021								$ 0	$ 96	394,380	(384,753)	9,723
Issuance of common stock in public offerings, net of commissions and issuance costs (in shares)	7,600	0
Issuance of common stock in public offerings, net of commissions and issuance costs	$ 0	$ 0	$ 6,721	$ 0	$ 6,721
Conversion of Series B preferred stock into common stock (in shares)	(5,200)	650,000
Employee stock-based compensation								0	0	52	0	52
Accretion of Series A preferred stock dividends								0	0	(1,127)	0	(1,127)
Net and comprehensive loss								$ 0	$ 0	0	(5,140)	(5,140)
Conversion of Series D preferred stock into common stock	$ 0	$ 1	$ 0	$ 0	$ 1
Issuance of common stock upon vesting of restricted stock units (in shares)								0	417
Reclassifications and adjustments due to rounding impact from reverse stock split for fractional shares (in shares)								0	26,169
Reclassifications and adjustments due to rounding impact from reverse stock split for fractional shares								$ 0	$ (92)	92	0	0
Balance (in shares) at Mar. 31, 2022								58,851	5,454,849
Balance at Mar. 31, 2022								$ 0	$ 5	$ 400,118	$ (389,893)	$ 10,230

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities
Net loss	$ (5,140)	$ (5,052)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	15	194
Amortization of debt issuance costs and debt discount	21	28
Stock-based compensation	52	418
Noncash interest expense and other charges	419	370
Change in right of use asset	24	34
Provision for excess and obsolete inventories	8	7
Other non-cash charges	1	2
Changes in operating assets and liabilities:
Accounts receivable	28	(49)
Inventories	(875)	(67)
Prepaid expenses and other current assets	(1,015)	(968)
Other assets	(10)	0
Accounts payable	(223)	84
Accrued compensation	272	(135)
Accrued expenses and other current liabilities	98	187
Other long-term liabilities	144	144
Net cash used in operating activities	(6,181)	(4,803)
Cash flows from investing activities
Purchase of property and equipment	(31)	(11)
Net cash used in investing activities	(31)	(11)
Cash flows from financing activities
Net cash provided by financing activities	6,721	13,077
Net change in cash and cash equivalents	509	8,263
Cash and cash equivalents, beginning of period	19,497	22,185
Cash and cash equivalents, end of period	20,006	30,448
Noncash investing and financing activities:
Accretion of Series A preferred stock dividends	1,127	1,044
Transfers between inventory and property and equipment	118	0
Reclassification of right of use asset to prepaid rent	(24)	(34)
Common Stock [Member]
Cash flows from financing activities
Proceeds from the issuance of convertible preferred stock, net of commissions and issuance costs	6,721	0
Preferred Stock [Member]
Cash flows from financing activities
Proceeds from the issuance of convertible preferred stock, net of commissions and issuance costs	$ 0	$ 13,077

Note 1 - Organization

Note 1 - Organization	3 Months Ended
	Mar. 31, 2022
Notes to Financial Statements
Nature of Operations [Text Block]	1. Organization, Nature of Business Avinger, Inc. (the “Company”), a Delaware corporation, was incorporated in March 2007. “OCT”) Liquidity Matters In the course of its activities, the Company has incurred losses and negative cash flows from operations since its inception. As of March 31, 2022, March 31, 2022 second 2023. January 2022 February 2021. may The Company can provide no not may twelve no 19 If the Company is unable to raise additional capital in sufficient amounts or on terms acceptable to it, the Company may one not On September 22, 2021, not 5550 2 $1 30 180 March 21, 2022, not March 21, 2022. 5810 3 March 22, 2022, 180 September 19, 2022, On March 29, 2022, $1.00 10 no Public Offerings Past Offerings On February 2, 2021, January 2022 On January 14, 2022, “January 2022 In connection with the January 2022 March 11, 2022 1 1 March 11, 2022, 1 5:00 March 14, 2022. Pursuant to the purchase agreement, the Company filed a certificate of designation (the “Certificate of Designation”) with the Secretary of State of Delaware designating the rights, preferences and limitations of the shares of Series D preferred stock, which became effective on January 14, 2022. no March 11, 2022, no The holders of the Series D preferred stock are entitled to dividends, on an as-if converted basis, equal to dividends actually paid, if any, on shares of Common Stock. The Series D preferred stock is convertible into shares of common stock at a conversion price of $8.00 per share, as adjusted for the most recent reverse stock split. The conversion price can be adjusted pursuant to the Certificate of Designation for stock dividends and stock splits, subsequent rights offerings, pro rata distributions of dividends or the occurrence of a fundamental transaction (as defined in the Certificate of Designation). The Series D preferred stock can be converted at the option of the holders at any time. In addition, subject to the satisfaction of certain conditions, the Company may 4.99% 9.99% may, not 9.99%. The 807,500 Common Warrants have an exercise price of $9.60 per share and become exercisable beginning July 14, 2022. five July 14, 2027. five January 2022 January 12, 2027.

Note 2 - Summary of Significant

Note 2 - Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2022
Notes to Financial Statements
Basis of Presentation and Significant Accounting Policies [Text Block]	2. Basis of Presentation The accompanying unaudited condensed financial statements have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”) and pursuant to the rules and regulations of the SEC (“SEC”). The accompanying unaudited condensed interim financial statements have been prepared on the same basis as the annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for a fair statement of the Company’s financial information. The results for the three March 31, 2022 not December 31, 2022, December 31, 2021 10 December 31, 2021, March 22, 2022. 2 10 December 31, 2021. On March 11, 2022, 1 March 14, 2022. not Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts and disclosures reported in the financial statements. Management uses significant judgment when making estimates related to its stock-based compensation, accruals related to compensation, the valuation of the common stock warrants, provisions for doubtful accounts receivable and excess and obsolete inventories, clinical trial accruals, and its reserves for sales returns and warranty costs. Management bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not may may Concentration of Credit Risk, and Other Risks and Uncertainties Financial instruments that potentially subject the Company to credit risk consist of cash and cash equivalents and accounts receivable to the extent of the amounts recorded on the balance sheets. The Company’s policy is to invest in cash and cash equivalents, consisting of money market funds. These financial instruments are held in Company accounts at one March 31, 2022 December 31, 2021. The Company’s accounts receivable are due from a variety of healthcare organizations in the United States and select international markets. At March 31, 2022 December 31, 2021, one three March 31, 2022, three March 31, 2021, Product Warranty Costs The Company typically offers a one Three Months Ended March 31, 2022 2021 Beginning balance $ 187 $ 193 Warranty provision 4 20 Usage/Release (20 ) (2 ) Ending balance $ 171 $ 211 Net Loss per Share Attributable to Common Stockholders Basic net loss per share applicable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted average number of shares of common stock outstanding during the period, without consideration for potential dilutive common shares. Diluted net loss per share applicable to common stockholders is computed by dividing the net loss attributable to common stockholder by the weighted average number of shares of common stock and dilutive potential shares of common stock outstanding during the period. Any common stock shares subject to repurchase are excluded from the calculations as the continued vesting of such shares is contingent upon the holders’ continued service to the Company. As of March 31, 2022 2021, no Net loss per share applicable to common stockholders was determined as follows (in thousands, except per share data): Three Months Ended March 31, 2022 2021 Net loss applicable to common stockholders $ (11,378 ) $ (6,096 ) Weighted average common stock outstanding, basic and diluted 4,889 4,572 Net loss per share attributable to common stockholders, basic and diluted $ (2.33 ) $ (1.33 ) The following potentially dilutive securities outstanding have been excluded from the computations of diluted weighted average shares outstanding because such securities have an anti-dilutive impact due to losses reported: Three Months Ended March 31, 2022 2021 Common stock warrants equivalents 871,808 137,700 Common stock options 331 339 Convertible preferred stock 62,002 2,617 Unvested restricted stock units 9,866 21,043 944,007 161,699 Segment and Geographical Information The Company operates and manages its business as one three March 31, 2022 2021, As of March 31, 2022 December 31, 2021, 1 March 31, 2022 December 31, 2021, no 2 3. no three March 31, 2022. Recent Accounting Pronouncements Recently adopted accounting standards In May 2021, No. 2021 04, Issuer s Accounting for Certain Modifications of Exchanges of Freestanding Equity-Classified Written Call Options January 1, 2022. not Recent accounting standards not In August 2020, No. 2020 06, Debt Debt with Conversion and Other Options (Subtopic 470 20 Contracts in Entity s Own Equity (Subtopic 815 40 s Own Equity not 815 first 2024 not

Note 3 - Inventories

Note 3 - Inventories	3 Months Ended
	Mar. 31, 2022
Notes to Financial Statements
Inventory Disclosure [Text Block]	3. Inventories consisted of the following (in thousands): March 31, 2022 December 31, 2021 Raw materials $ 2,530 $ 2,503 Work-in-process 989 1 Finished products 1,831 2,097 Total inventories $ 5,350 $ 4,601

Note 4 - Borrowings

Note 4 - Borrowings	3 Months Ended
	Mar. 31, 2022
Notes to Financial Statements
Debt Disclosure [Text Block]	4. CRG On September 22, 2015, March 29, 2017. September 22, 2015. June 15, 2016 On February 14, 2018, We have entered into several amendments to the Term Loan Agreement (the “Amendments”) with CRG since September 2015, January 22, 2021. 1 December 31, 2023; 2 may December 31, 2023 no 3 December 31, 2023 no 4 December 31, 2025; ( 5 6 2018, 2019 2020; 7 2021, 2022; 8 2023, 2024 2025; 9 no December 31, 2020; ( 10 19 not 11 Under the amended Loan Agreement, no first 2024. not first 2024, 2024, 2025. December 31, 2025. The Company may no seven The Loan Agreement requires that the Company adheres to certain affirmative and negative covenants, including financial reporting requirements, certain minimum financial covenants for pre-specified liquidity and revenue requirements and a prohibition against the incurrence of indebtedness, or creation of additional liens, other than as specifically permitted by the terms of the Loan Agreement. In particular, the covenants of the amended Loan Agreement included a covenant that the Company maintain a minimum of $3.5 million of cash and certain cash equivalents, and the Company has to achieve certain minimum revenues. If the Company fails to meet the applicable minimum revenue target in any calendar year, the Loan Agreement provides the Company with a cure right if it prepays a portion of the outstanding principal equal to 2.0 times the revenue shortfall. In addition, the Loan Agreement prohibits the payment of cash dividends on the Company’s capital stock and also places restrictions on mergers, sales of assets, investments, incurrence of liens, incurrence of indebtedness and transactions with affiliates. CRG may As of March 31, 2022, As of March 31, 2022, Year Ending December 31, 2022 (remaining nine months of the year) $ — 2023 — 2024 9,045 2025 10,339 Total 19,384 Less: Amount of PIK additions and final facility fee to be incurred subsequent to March 31, 2022 (6,345 ) Less: Amount representing debt financing costs (312 ) Borrowings, long-term portion, as of March 31, 2022 $ 12,727 In connection with drawdowns under the Loan Agreement, the Company recorded aggregate debt discounts of $1.3 million as contra-debt. The debt discounts are being amortized as non-cash interest expense using the effective interest method over the term of the Loan Agreement. As of March 31, 2022 December 31, 2021, three March 31, 2022 2021, three March 31, 2022 2021, As of March 31, 2022, Paycheck Protection Program On April 23, 2020, April 20, 2020 ( April 20, 2022 1% six may no The PPP Loan was administered by the U.S. Small Business Administration (the “SBA”). The SBA was given the authority under the PPP to forgive loans if all employees were kept on the payroll for a required period and the loan proceeds were used for payroll, rent and utilities. The Company applied for debt forgiveness in December 2020. On April 17, 2021, no April 2021 March 31, 2021,

Note 5 - Leases

Note 5 - Leases	3 Months Ended
	Mar. 31, 2022
Notes to Financial Statements
Lessee, Operating Leases [Text Block]	5. The Company’s operating lease obligations primarily consist of leased office, laboratory, and manufacturing space under a non-cancelable operating lease. In addition to the minimum future lease commitments presented below, the lease requires the Company to pay property taxes, insurance, maintenance, and repair costs. The lease includes a rent holiday concession and escalation clauses for increased rent over the lease term. Rent expense is recognized using the straight-line method over the term of the lease. The Company records deferred rent calculated as the difference between rent expense and the cash rental payments. The lease will expire on November 30, 2024. November 2024, December 1, 2019. March 31, 2022 The operating lease was included on the balance sheet at the present value of the future base payments discounted at a 6.5% discount rate using the rate of interest that the Company would have to pay to borrow on a collateralized basis over a similar term and amount equal to the lease payments in a similar economic environment as the lease does provide an implicit rate. The Company’s operating lease expense, excluding variable maintenance fees and other expenses on a monthly basis, was approximately $105,000. Rent expense for both the three March 31, 2022 2021 three March 31, 2022 2021 three March 31, 2022 2021 March 31, 2022 December 31, 2021, The following table presents the future operating lease payments and leasehold liability included on the balance sheet related to the Company’s operating lease as of March 31, 2022 ( Year Ending December 31, 2022 (remaining nine months of the year) $ 873 2023 1,203 2024 1,138 Total 3,214 Less: Imputed interest (274 ) Leasehold liability as of March 31, 2022 $ 2,940 The following table shows ROU assets and lease liabilities, and the associated financial statement line items, as of March 31, 2022 December 31, 2021 ( Lease-Related Assets and Liabilities Financial Statement Line Items March 31, 2022 December 31, 2021 Right of use assets: Operating lease Right of use asset $ 2,940 $ 3,179 Total right of use assets $ 2,940 $ 3,179 Lease liabilities: Operating lease Leasehold liability, current portion $ 1,011 $ 985 Leasehold liability, long-term portion 1,929 2,194 Total lease liabilities $ 2,940 $ 3,179

Note 6 - Commitments and Contin

Note 6 - Commitments and Contingencies	3 Months Ended
	Mar. 31, 2022
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	6. Purchase Obligations Purchase obligations consist of agreements to purchase goods and services entered into in the ordinary course of business. The Company had non-cancelable commitments to suppliers for purchases totaling approximately $1.2 million as of March 31, 2022. Legal Proceedings The Company is not may

Note 7 - Stockholders' Equity

Note 7 - Stockholders' Equity	3 Months Ended
	Mar. 31, 2022
Notes to Financial Statements
Stockholders' Equity Note Disclosure [Text Block]	7. Equity Convertible Preferred Stock As of March 31, 2022 December 31, 2021, March 31, 2022 December 31, 2021, Series A Convertible Preferred Stock The holders of Series A preferred stock are entitled to receive annual accruing dividends at a rate of 8%, payable in additional shares of Series A preferred stock or cash, at the Company’s option. The shares of Series A preferred stock have a liquidation preference of $1,000 per share, no December 31, 2021, March 31, 2022 December 31, 2021, March 31, 2022 2021, Series B Convertible Preferred Stock The Series B preferred stock has a liquidation preference of $0.001 per share, full ratchet price based anti-dilution protection, has no no not December 31, 2021, March 31, 2022 December 31, 2021, Series D Convertible Preferred Stock On January 14, 2022, “January 2022 $1,000 three March 31, 2022, March 31, 2022, On April 1, 2022 May 6, 2022, The Series D preferred stock can be converted at the option of the holders at any time. In addition, subject to the satisfaction of certain conditions, the Company may may, not 9.99%. The Series D preferred stock does not one 1 1 March 11, 2022. The Company evaluated the classification of the Series D preferred stock and determined equity classification was appropriate due to no first The embedded conversion feature was evaluated and bifurcation from the preferred stock equity host was not March 14, 2022, one three March 31, 2022. Common Stock As of March 31, 2022, Common Stock Warrants As of March 31, 2022, Total Outstanding and Exercisable Underlying Shares of Common Stock Exercise Price per Share Expiration Date Series 1 Warrants issued in the February 2018 Series B financing 8,979,000 44,895 $ 400.00 February 2025 Series 2 Warrants issued in the February 2018 Series B financing 8,709,500 43,548 $ 400.00 February 2025 Warrants issued in the November 2018 financing 8,768,395 43,842 $ 80.00 November 2023 Total as of December 31, 2021 26,456,895 132,265 Placement agent warrants issued in the January 2022 financing 1,330,000 66,500 $ 10.00 January 2027 Warrants issued in the January 2022 financing 16,150,000 807,500 $ 9.60 July 2027 Total as of March 31, 2022 43,936,895 1,006,285 Pursuant to the purchase agreement entered into on January 14, 2022, July 14, 2022. five July 14, 2027. The Common Warrants can be exercised at the option of the holders at any time after they become exercisable provided that shares of the Common Warrants cannot be exercised into common stock if the applicable holder would beneficially own in excess of 4.99% (or, upon election by such holder prior to the issuance of any shares of Common Warrants, 9.99%) of the Company’s outstanding common stock immediately after giving effect to the exercise. A holder of the Common Warrants may, not 9.99%. The Company also issued to the placement agent of the January 2022 five January 2022 January 12, 2027. As of March 31, 2022 December 31, 2021, Stock Plans In January 2015, 2015 “2015 March 31, 2022, 2015 The Company’s RSUs generally vest annually over three Number of Shares Weighted Average Grant Date Fair Value Weighted Average Remaining Contractual Term Awards outstanding at December 31, 2021 10,060 $ 24.39 0.72 Awarded — $ — — Released (417 ) $ 11.64 — Forfeited (84 ) $ 23.00 — Awards outstanding at March 31, 2022 9,559 $ 24.95 0.48 As of March 31, 2022, March 31, 2022 March 31, 2022, three March 31, 2022 2021, three March 31, 2022 2021, 2018 On August 22, 2018, may August 28, 2019 March 10, 2020, no three March 31, 2022 2021. March 31, 2022,

Note 8 - Stock-based Compensati

Note 8 - Stock-based Compensation	3 Months Ended
	Mar. 31, 2022
Notes to Financial Statements
Share-Based Payment Arrangement [Text Block]	8. Total non-cash stock-based compensation expense relating to the Company’s stock options and RSUs recognized during the three March 31, 2022 2021, Three Months Ended March 31, 2022 2021 Cost of revenues $ 7 $ 34 Research and development expenses 13 111 Selling, general and administrative expenses 32 273 $ 52 $ 418

Note 9 - Subsequent Events

Note 9 - Subsequent Events	3 Months Ended
	Mar. 31, 2022
Notes to Financial Statements
Subsequent Events [Text Block]	9. Departure of Officer On April 29, 2022, May 12, 2022. no

Significant Accounting Policies

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation The accompanying unaudited condensed financial statements have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”) and pursuant to the rules and regulations of the SEC (“SEC”). The accompanying unaudited condensed interim financial statements have been prepared on the same basis as the annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for a fair statement of the Company’s financial information. The results for the three March 31, 2022 not December 31, 2022, December 31, 2021 10 December 31, 2021, March 22, 2022. 2 10 December 31, 2021. On March 11, 2022, 1 March 14, 2022. not
Use of Estimates, Policy [Policy Text Block]	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts and disclosures reported in the financial statements. Management uses significant judgment when making estimates related to its stock-based compensation, accruals related to compensation, the valuation of the common stock warrants, provisions for doubtful accounts receivable and excess and obsolete inventories, clinical trial accruals, and its reserves for sales returns and warranty costs. Management bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not may may
Concentration of Credit Risk and Other Risks and Uncertainties [Policy Text Block]	Concentration of Credit Risk, and Other Risks and Uncertainties Financial instruments that potentially subject the Company to credit risk consist of cash and cash equivalents and accounts receivable to the extent of the amounts recorded on the balance sheets. The Company’s policy is to invest in cash and cash equivalents, consisting of money market funds. These financial instruments are held in Company accounts at one March 31, 2022 December 31, 2021. The Company’s accounts receivable are due from a variety of healthcare organizations in the United States and select international markets. At March 31, 2022 December 31, 2021, one three March 31, 2022, three March 31, 2021,
Standard Product Warranty, Policy [Policy Text Block]	Product Warranty Costs The Company typically offers a one Three Months Ended March 31, 2022 2021 Beginning balance $ 187 $ 193 Warranty provision 4 20 Usage/Release (20 ) (2 ) Ending balance $ 171 $ 211
Earnings Per Share, Policy [Policy Text Block]	Net Loss per Share Attributable to Common Stockholders Basic net loss per share applicable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted average number of shares of common stock outstanding during the period, without consideration for potential dilutive common shares. Diluted net loss per share applicable to common stockholders is computed by dividing the net loss attributable to common stockholder by the weighted average number of shares of common stock and dilutive potential shares of common stock outstanding during the period. Any common stock shares subject to repurchase are excluded from the calculations as the continued vesting of such shares is contingent upon the holders’ continued service to the Company. As of March 31, 2022 2021, no Net loss per share applicable to common stockholders was determined as follows (in thousands, except per share data): Three Months Ended March 31, 2022 2021 Net loss applicable to common stockholders $ (11,378 ) $ (6,096 ) Weighted average common stock outstanding, basic and diluted 4,889 4,572 Net loss per share attributable to common stockholders, basic and diluted $ (2.33 ) $ (1.33 ) The following potentially dilutive securities outstanding have been excluded from the computations of diluted weighted average shares outstanding because such securities have an anti-dilutive impact due to losses reported: Three Months Ended March 31, 2022 2021 Common stock warrants equivalents 871,808 137,700 Common stock options 331 339 Convertible preferred stock 62,002 2,617 Unvested restricted stock units 9,866 21,043 944,007 161,699
Segment Reporting, Policy [Policy Text Block]	Segment and Geographical Information The Company operates and manages its business as one three March 31, 2022 2021, As of March 31, 2022 December 31, 2021, 1 March 31, 2022 December 31, 2021, no 2 3. no three March 31, 2022.
New Accounting Pronouncements, Policy [Policy Text Block]	Recent Accounting Pronouncements Recently adopted accounting standards In May 2021, No. 2021 04, Issuer s Accounting for Certain Modifications of Exchanges of Freestanding Equity-Classified Written Call Options January 1, 2022. not Recent accounting standards not In August 2020, No. 2020 06, Debt Debt with Conversion and Other Options (Subtopic 470 20 Contracts in Entity s Own Equity (Subtopic 815 40 s Own Equity not 815 first 2024 not

Note 2 - Summary of Significa_2

Note 2 - Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2022
Notes Tables
Schedule of Product Warranty Liability [Table Text Block]	Three Months Ended March 31, 2022 2021 Beginning balance $ 187 $ 193 Warranty provision 4 20 Usage/Release (20 ) (2 ) Ending balance $ 171 $ 211
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	Three Months Ended March 31, 2022 2021 Net loss applicable to common stockholders $ (11,378 ) $ (6,096 ) Weighted average common stock outstanding, basic and diluted 4,889 4,572 Net loss per share attributable to common stockholders, basic and diluted $ (2.33 ) $ (1.33 )
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	Three Months Ended March 31, 2022 2021 Common stock warrants equivalents 871,808 137,700 Common stock options 331 339 Convertible preferred stock 62,002 2,617 Unvested restricted stock units 9,866 21,043 944,007 161,699

Note 3 - Inventories (Tables)

Note 3 - Inventories (Tables)	3 Months Ended
	Mar. 31, 2022
Notes Tables
Schedule of Inventory, Current [Table Text Block]	March 31, 2022 December 31, 2021 Raw materials $ 2,530 $ 2,503 Work-in-process 989 1 Finished products 1,831 2,097 Total inventories $ 5,350 $ 4,601

Note 4 - Borrowings (Tables)

Note 4 - Borrowings (Tables)	3 Months Ended
	Mar. 31, 2022
Notes Tables
Schedule of Debt [Table Text Block]	Year Ending December 31, 2022 (remaining nine months of the year) $ — 2023 — 2024 9,045 2025 10,339 Total 19,384 Less: Amount of PIK additions and final facility fee to be incurred subsequent to March 31, 2022 (6,345 ) Less: Amount representing debt financing costs (312 ) Borrowings, long-term portion, as of March 31, 2022 $ 12,727

Note 5 - Leases (Tables)

Note 5 - Leases (Tables)	3 Months Ended
	Mar. 31, 2022
Notes Tables
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	Year Ending December 31, 2022 (remaining nine months of the year) $ 873 2023 1,203 2024 1,138 Total 3,214 Less: Imputed interest (274 ) Leasehold liability as of March 31, 2022 $ 2,940
Right of Use Asset and Liabilities [Table Text Block]	Lease-Related Assets and Liabilities Financial Statement Line Items March 31, 2022 December 31, 2021 Right of use assets: Operating lease Right of use asset $ 2,940 $ 3,179 Total right of use assets $ 2,940 $ 3,179 Lease liabilities: Operating lease Leasehold liability, current portion $ 1,011 $ 985 Leasehold liability, long-term portion 1,929 2,194 Total lease liabilities $ 2,940 $ 3,179

Note 7 - Stockholders' Equity (

Note 7 - Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2022
Notes Tables
Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]	Total Outstanding and Exercisable Underlying Shares of Common Stock Exercise Price per Share Expiration Date Series 1 Warrants issued in the February 2018 Series B financing 8,979,000 44,895 $ 400.00 February 2025 Series 2 Warrants issued in the February 2018 Series B financing 8,709,500 43,548 $ 400.00 February 2025 Warrants issued in the November 2018 financing 8,768,395 43,842 $ 80.00 November 2023 Total as of December 31, 2021 26,456,895 132,265 Placement agent warrants issued in the January 2022 financing 1,330,000 66,500 $ 10.00 January 2027 Warrants issued in the January 2022 financing 16,150,000 807,500 $ 9.60 July 2027 Total as of March 31, 2022 43,936,895 1,006,285
Share-Based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block]	Number of Shares Weighted Average Grant Date Fair Value Weighted Average Remaining Contractual Term Awards outstanding at December 31, 2021 10,060 $ 24.39 0.72 Awarded — $ — — Released (417 ) $ 11.64 — Forfeited (84 ) $ 23.00 — Awards outstanding at March 31, 2022 9,559 $ 24.95 0.48

Note 8 - Stock-based Compensa_2

Note 8 - Stock-based Compensation (Tables)	3 Months Ended
	Mar. 31, 2022
Notes Tables
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]	Three Months Ended March 31, 2022 2021 Cost of revenues $ 7 $ 34 Research and development expenses 13 111 Selling, general and administrative expenses 32 273 $ 52 $ 418

Note 1 - Organization (Details

Note 1 - Organization (Details Textual) $ / shares in Units, $ in Thousands	Mar. 11, 2022	Mar. 01, 2022	Jan. 14, 2022USD ($)$ / sharesshares	Feb. 02, 2021USD ($)$ / sharesshares	Jan. 31, 2022USD ($)	Feb. 28, 2021USD ($)	Mar. 31, 2022USD ($)$ / sharesshares	Dec. 31, 2021USD ($)$ / sharesshares
Retained Earnings (Accumulated Deficit), Total | $							$ (389,893)	$ (384,753)
Cash and Cash Equivalents, at Carrying Value, Total | $							$ 20,006	$ 19,497
Share Price (in dollars per share)							$ 3.63
Preferred Stock, Par or Stated Value Per Share (in dollars per share)							$ 0.001	$ 0.001
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares							1,006,285	132,265
Class of Warrant or Right, Outstanding (in shares) | shares							43,936,895	26,456,895
Reverse Stock Split [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio	20
Reverse Stock Split [Member] | Minimum [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio	5	5
Reverse Stock Split [Member] | Maximum [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio	20
Common Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares			807,500
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)			$ 9.60
Warrants and Rights Outstanding, Term (Year)			5 years
Placement agent warrants issued in the January 2022 financing [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares			66,500				66,500
Class of Warrant or Right, Outstanding (in shares) | shares							1,330,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)			$ 10				$ 10
Warrants and Rights Outstanding, Term (Year)			5 years
Series D Preferred Stock [Member]
Preferred Stock, Par or Stated Value Per Share (in dollars per share)			$ 0.001
Preferred Stock, Convertible, Conversion Price (in dollars per share)							$ 8
Series D Preferred Stock [Member] | Common Warrants [Member]
Class of Warrant or Right, Outstanding (in shares) | shares			807,500
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)			$ 9.60
Warrants and Rights Outstanding, Term (Year)			5 years
Series D Preferred Stock [Member] | Placement agent warrants issued in the January 2022 financing [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares			66,500
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)			$ 10
Warrants and Rights Outstanding, Term (Year)			5 years
January 2022 Public Offering [Member]
Proceeds from Issuance or Sale of Equity, Net | $			$ 6,700		$ 6,700
January 2022 Public Offering [Member] | Series D Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares			7,600
Shares Issued, Price Per Share (in dollars per share)			$ 1,000
Preferred Stock, Convertible, Conversion Price (in dollars per share)			8
Preferred Stock, Voting Rights Per Share (in dollars per share)			$ 37,500
February 2021 Public Offering [Member]
Proceeds from Issuance or Sale of Equity, Net | $				$ 13,000		$ 13,000
Stock Issued During Period, Shares, New Issues (in shares) | shares				500,000
Share Price (in dollars per share)				$ 28.80

Note 2 - Summary of Significa_3

Note 2 - Summary of Significant Accounting Policies (Details Textual)	Mar. 11, 2022	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Number of Reportable Segments		1
Customer Concentration Risk [Member] | Accounts Receivable [Member]
Number of Major Customers		1		1
Customer Concentration Risk [Member] | Accounts Receivable [Member] | One Customer [Member]
Concentration Risk, Percentage		13.00%		21.00%
Customer Concentration Risk [Member] | Revenue Benchmark [Member]
Number of Major Customers		1		0
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | UNITED STATES
Concentration Risk, Percentage		94.00%	94.00%
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | One Customer [Member]
Concentration Risk, Percentage		14.00%
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Zero Customer [Member]
Concentration Risk, Percentage				10.00%
Reverse Stock Split [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio	20

Note 2 - Summary of Significa_4

Note 2 - Summary of Significant Accounting Policies - Product Warranty (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Beginning balance	$ 187	$ 193
Warranty provision	4	20
Usage/Release	(20)	(2)
Ending balance	$ 171	$ 211

Note 2 - Summary of Significa_5

Note 2 - Summary of Significant Accounting Policies - Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Net loss applicable to common stockholders	$ (11,378)	$ (6,096)
Weighted average common stock outstanding, basic and diluted (in shares)	4,889	4,572
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (2.33)	$ (1.33)

Note 2 - Summary of Significa_6

Note 2 - Summary of Significant Accounting Policies - Anti-dilutive Securities (Details) - shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Antidilutive Securities (in shares)	944,007	161,699
Common Stock Warrants [Member]
Antidilutive Securities (in shares)	871,808	137,700
Common Stock Options [ member]
Antidilutive Securities (in shares)	331	339
Preferred Stock [Member]
Antidilutive Securities (in shares)	62,002	2,617
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities (in shares)	9,866	21,043

Note 3 - Inventories - Schedule

Note 3 - Inventories - Schedule of Inventory (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Raw materials	$ 2,530	$ 2,503
Work-in-process	989	1
Finished products	1,831	2,097
Total inventories	$ 5,350	$ 4,601

Note 4 - Borrowings (Details Te

Note 4 - Borrowings (Details Textual) - USD ($)	Jan. 22, 2021	Apr. 23, 2020	Feb. 14, 2018	Apr. 30, 2021	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Apr. 17, 2021	Jun. 15, 2016	Sep. 22, 2015
Interest Expense, Total					$ 439,000	$ 396,000
Paycheck Protection Program CARES Act [Member]
Proceeds from Issuance of Long-term Debt, Total		$ 2,300,000
Long-term Debt, Total								$ 0
Debt Instrument Interest Forgiven				$ 23,000
Interest Expense, Total				6,000
Paycheck Protection Program CARES Act [Member] | Other Nonoperating Income (Expense) [Member]
Gain (Loss) on Extinguishment of Debt, Total				$ 2,400,000
CRG [Member] | Loan Agreement [Member]
Debt Agreement, Maximum Borrowing Capacity										$ 50,000,000
Debt Instrument, Covenant Compliance, Minimum Liquidity Requirement			$ 3,500,000
Debt Instrument, Covenant Compliance, Target Minimum Revenue, Past Twelve Months							$ 8,000,000
Debt Instrument, Covenant Compliance Target Minimum Revenue, Next Twelve Months	$ 10
Debt Instrument, Covenant, Compliance Target Minimum Revenue Second Year	12,000,000
Debt Instrument, Covenant Compliance Target Minimum Revenue Third Year	14,500,000
Debt Instrument, Covenant Compliance Target Minimum Revenue Fourth Year	$ 17,000,000
Debt Instrument, Interest Rate, Stated Percentage	12.50%
Debt Instrument, Periodic Payment, Total	$ 1,900,000
Long-Term Debt, Maturity, Year Four	7,500,000
Long-Term Debt, Maturity, Year Five	$ 7,500,000
Debt Instrument, Redemption Initial Prepayment Premium Percentage	5.00%
Debt Instrument, Redemption Annual Decline in Prepayment Premium Percentage	1.00%
Debt Instrument, Redemption Prepayment Premium Percentage after Fifth Year	0.00%
Debt Instrument, Financing Fee Percentage	1.50%
Debt Instrument, Final Facility Fee Percentage	15.00%
Debt Instrument, Covenant Compliance Cash and Certain Cash Equivalents Minimum	$ 3,500,000
Debt Instrument, Covenant Compliance Prepayment Multiplier for Revenue Shortfall	2
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net, Total					312,000		$ 333,000			1,300,000
Amortization of Debt Discount (Premium)					21,000	38,000
Interest Expense, Debt, Total					$ 440,000	$ 393,000
CRG [Member] | Loan Agreement [Member] | Series A Preferred Stock Purchase Agreement with CRG [Member]
Debt Conversion, Original Debt, Amount			38,000,000
Debt Conversion, Fees and Prepayment Premium Amount			$ 3,800,000
CRG [Member] | Loan Agreement [Member] | First Tranche, Borrowed on September 22, 2015 [Member]
Debt Instrument, Face Amount										$ 30,000,000
CRG [Member] | Loan Agreement [Member] | Second Tranche, Borrowed on June 15, 2016 [Member]
Debt Instrument, Face Amount									$ 10,000,000

Note 4 - Borrowings - Schedule

Note 4 - Borrowings - Schedule of Debt (Details) - Loan Agreement [Member] - CRG [Member] $ in Thousands	Mar. 31, 2022USD ($)
2022 (remaining nine months of the year)	$ 0
2023	0
2024	9,045
2025	10,339
Total	19,384
Less: Amount of PIK additions and final facility fee to be incurred subsequent to March 31, 2022	(6,345)
Less: Amount representing debt financing costs	(312)
Borrowings, long-term portion, as of March 31, 2022	$ 12,727

Note 5 - Leases (Details Textua

Note 5 - Leases (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Apr. 01, 2019
Lessee, Operating Lease, Liability, Payments, Due, Total	$ 3,214,000			$ 5,800,000
Operating Lease, Weighted Average Remaining Lease Term (Year)	2 years 8 months 12 days
Lessee, Operating Lease, Discount Rate			6.50%
Operating Lease, Expense, Excluding Maintenance Fee and Other Expense, Monthly	$ 105,000
Operating Lease, Expense	314,000	$ 314,000
Variable Lease, Cost	66,000	59,000
Operating Lease, Right-of-Use Asset, Amortization Expense	264,000	$ 249,000
Prepaid Rent	$ 150,000		$ 158,000

Note 5 - Leases - Future Operat

Note 5 - Leases - Future Operating Lease Payments (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Apr. 01, 2019
2022 (remaining nine months of the year), future operating lease payments	$ 873
2023, future operating lease payments	1,203
2024, future operating lease payments	1,138
Total, future operating lease payments	3,214		$ 5,800
Less: Imputed interest	(274)
Leasehold liability as of March 31, 2022	$ 2,940	$ 3,179

Note 5 - ROU Assets and Lease L

Note 5 - ROU Assets and Lease Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Operating lease	$ 2,940	$ 3,179
Total right of use assets	2,940	3,179
Operating lease	1,011	985
Operating Lease, Liability, Noncurrent	1,929	2,194
Total lease liabilities	$ 2,940	$ 3,179

Note 6 - Commitments and Cont_2

Note 6 - Commitments and Contingencies (Details Textual) $ in Millions	Mar. 31, 2022USD ($)
Purchase Commitment [Member]
Purchase Obligation, Total	$ 1.2

Note 7 - Stockholders' Equity_2

Note 7 - Stockholders' Equity (Details Textual)	May 06, 2022shares	Apr. 01, 2022shares	Mar. 11, 2022	Mar. 01, 2022	Jan. 14, 2022USD ($)$ / sharesshares	Feb. 14, 2018	Mar. 31, 2022USD ($)$ / sharesshares	Mar. 31, 2021USD ($)	Dec. 31, 2021$ / sharesshares	May 10, 2022shares	Mar. 10, 2020shares	Aug. 28, 2019shares	Aug. 22, 2018shares	Feb. 16, 2018$ / shares
Preferred Stock, Shares Authorized (in shares)							5,000,000		5,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares							$ 0.001		$ 0.001
Preferred Stock, Shares Issued (in shares)							58,851		56,451
Preferred Stock, Shares Outstanding, Ending Balance (in shares)							58,851		56,451
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)							1,006,285		132,265
Preferred Stock Redemption Discount | $							$ 5,111,000	$ 0
Common Stock, Shares Authorized (in shares)							100,000,000		100,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares							$ 0.001		$ 0.001
Common Stock, Shares, Issued (in shares)							5,454,849		4,778,263
Common Stock, Shares, Outstanding, Ending Balance (in shares)							5,454,849		4,778,263
Share Price (in dollars per share) | $ / shares							$ 3.63
Share-Based Payment Arrangement, Expense | $							$ 52,000	418,000
Restricted Stock Units (RSUs) [Member]
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total | $							$ 100,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)							6 months
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Fair Value | $							$ 100,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value | $							3,000	87,000
Share-Based Payment Arrangement, Expense | $							$ 52,000	400,000
The 2015 Employee Stock Purchase Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)							8,564
Officer and Director Share Purchase Plan [Member]
Common Stock, Shares, Issued (in shares)							0
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)							4,609
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)											6,250	2,000	1,000
Measurement Input, Expected Term [Member]
Warrants and Rights Outstanding, Measurement Input					5.5
Measurement Input, Price Volatility [Member]
Warrants and Rights Outstanding, Measurement Input					136.61
Measurement Input, Discount Rate [Member]
Warrants and Rights Outstanding, Measurement Input					1.51
Measurement Input, Expected Dividend Rate [Member]
Warrants and Rights Outstanding, Measurement Input					0
Reverse Stock Split [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio			20
Minimum [Member] | Restricted Stock Units (RSUs) [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)							3 years
Minimum [Member] | Reverse Stock Split [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio			5	5
Maximum [Member] | Reverse Stock Split [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio			20
Common Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)					807,500
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares					$ 9.60
Warrants and Rights Outstanding, Term (Year)					5 years
Common Stock Warrants, Issued with Series D Convertible Preferred Stock [Member]
Proceeds from Issuance of Warrants | $					$ 3,591
Placement agent warrants issued in the January 2022 financing [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)					66,500		66,500
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares					$ 10		$ 10
Warrants and Rights Outstanding, Term (Year)					5 years
January 2022 Public Offering [Member]
Proceeds from Issuance of Convertible Preferred Stock | $					$ 4,009
Conversion of Series B Preferred Stock into Common Stock [Member]
Conversion of Stock, Shares Converted (in shares)									93
Conversion of Stock, Shares Issued (in shares)									18,600
Conversion of Series D Preferred Stock into Common Stock [Member]
Conversion of Stock, Shares Converted (in shares)							5,200
Conversion of Stock, Shares Issued (in shares)							650,000
Conversion of Series D Preferred Stock into Common Stock [Member] | Subsequent Event [Member]
Conversion of Stock, Shares Converted (in shares)	1,200	600
Conversion of Stock, Shares Issued (in shares)	150,000	75,000
Series A Preferred Stock [Member]
Preferred Stock, Shares Outstanding, Ending Balance (in shares)							56,366
Preferred Stock, Liquidation Preference Per Share (in dollars per share) | $ / shares							$ 1,000
Preferred Stock, Convertible, Conversion Price (in dollars per share) | $ / shares							$ 400
Dividends, Preferred Stock, Total | $							$ 1,100,000	$ 1,000,000
Series A Preferred Stock [Member] | CRG [Member]
Preferred Stock Dividends, Shares (in shares)									4,175
Series A Preferred Stock [Member] | Conversion of Principal Amount of Senior Secured Loan to Newly Authorized Series A Preferred Stock [Member]
Preferred Stock, Dividend Rate, Percentage						8.00%
Series B Preferred Stock [Member]
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares														$ 0.001
Preferred Stock, Shares Outstanding, Ending Balance (in shares)							85		85
Preferred Stock, Convertible, Conversion Price (in dollars per share) | $ / shares							$ 5
Series D Preferred Stock [Member]
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares					$ 0.001
Preferred Stock, Shares Outstanding, Ending Balance (in shares)							2,400
Preferred Stock, Convertible, Conversion Price (in dollars per share) | $ / shares							$ 8
Series D Preferred Stock [Member] | Subsequent Event [Member]
Preferred Stock, Shares Outstanding, Ending Balance (in shares)										600
Preferred Stock, Convertible, Shares Issuable (in shares)										75,000
Series D Preferred Stock [Member] | Common Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares					$ 9.60
Warrants and Rights Outstanding, Term (Year)					5 years
Series D Preferred Stock [Member] | Placement agent warrants issued in the January 2022 financing [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)					66,500
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares					$ 10
Warrants and Rights Outstanding, Term (Year)					5 years
Series D Preferred Stock [Member] | January 2022 offering [Member]
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares					$ 0.001
Preferred Stock, Convertible, Conversion Price (in dollars per share) | $ / shares					$ 8
Stock Issued During Period, Shares, New Issues (in shares)					7,600
Shares Issued, Price Per Share (in dollars per share) | $ / shares					$ 1,000
Preferred Stock, Convertible, Shares Issuable (in shares)					950,000
Series D Preferred Stock [Member] | January 2022 offering [Member] | Common Warrants [Member]
Conversion of Warrants Allowed Maximum Ownership of Common Stock Percentage					4.99%
Conversion of Warrants Allowed Maximum Ownership of Common Stock Percentage upon Election					9.99%
Series D Preferred Stock [Member] | January 2022 Public Offering [Member]
Preferred Stock, Liquidation Preference Per Share (in dollars per share) | $ / shares					$ 0.01
Preferred Stock, Convertible, Conversion Price (in dollars per share) | $ / shares					$ 8
Stock Issued During Period, Shares, New Issues (in shares)					7,600
Shares Issued, Price Per Share (in dollars per share) | $ / shares					$ 1,000
Conversion of Preferred Stock Allowed, Maximum Ownership of Common Stock, Percentage					4.99%
Conversion of Preferred Stock Allowed, Maximum Ownership of Common Stock, Percentage upon Election					9.99%
Preferred Stock, Voting Rights Per Share (in dollars per share) | $ / shares					$ 37,500

Note 7 - Stockholder's Equity -

Note 7 - Stockholder's Equity - Outstanding Warrants (Details) - $ / shares	Mar. 31, 2022	Jan. 14, 2022	Dec. 31, 2021
Total outstanding and exercisable (in shares)	43,936,895		26,456,895
Underlying shares of common stock (in shares)	1,006,285		132,265
Series 1 February 2018 Warrants [Member]
Total outstanding and exercisable (in shares)			8,979,000
Underlying shares of common stock (in shares)			44,895
Exercise price per share (in dollars per share)			$ 400
Series 2 February 2018 Warrants [Member]
Total outstanding and exercisable (in shares)			8,709,500
Underlying shares of common stock (in shares)			43,548
Exercise price per share (in dollars per share)			$ 400
November 2018 Warrants [Member]
Total outstanding and exercisable (in shares)			8,768,395
Underlying shares of common stock (in shares)			43,842
Exercise price per share (in dollars per share)			$ 80
Placement agent warrants issued in the January 2022 financing [Member]
Total outstanding and exercisable (in shares)	1,330,000
Underlying shares of common stock (in shares)	66,500	66,500
Exercise price per share (in dollars per share)	$ 10	$ 10
Warrants Issued in the January 2022 Financing [Member]
Total outstanding and exercisable (in shares)	16,150,000
Underlying shares of common stock (in shares)	807,500
Exercise price per share (in dollars per share)	$ 9.60

Note 7 - Stockholders' Equity -

Note 7 - Stockholders' Equity - Restricted Stock Units Award Activity (Details) - Restricted Stock Units (RSUs) [Member] - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Awards outstanding, shares (in shares)	10,060
Awards outstanding, Weighted Average Grant Date Fair Value (in dollars per share)	$ 24.39
Awards outstanding, Weighted Average Remaining Contractual Term (Year)	5 months 23 days	8 months 19 days
Awarded, shares (in shares)	0
Awarded, Weighted Average Grant Date Fair Value (in dollars per share)	$ 0
Released, shares (in shares)	(417)
Released, Weighted Average Grant Date Fair Value (in dollars per share)	$ 11.64
Forfeited, shares (in shares)	(84)
Forfeited, , Weighted Average Grant Date Fair Value (in dollars per share)	$ 23
Awards outstanding, shares (in shares)	9,559	10,060
Awards outstanding, Weighted Average Grant Date Fair Value (in dollars per share)	$ 24.95	$ 24.39

Note 8 - Stock-based Compensa_3

Note 8 - Stock-based Compensation - Noncash Stock-based Compensation Expense Related to Stock Options, ESPP, and RSUs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Allocated Share-based Compensation Expense	$ 52	$ 418
Cost of Sales [Member]
Allocated Share-based Compensation Expense	7	34
Research and Development Expense [Member]
Allocated Share-based Compensation Expense	13	111
Selling, General and Administrative Expenses [Member]
Allocated Share-based Compensation Expense	$ 32	$ 273

Note 9 - Subsequent Events (Det

Note 9 - Subsequent Events (Details Textual) $ in Millions	Apr. 29, 2022USD ($)
Subsequent Event [Member] | Chief Financial Officer [Member]
Adjustment to Accrued Compensation	$ 0.1