Avinger (AVGR) 10-Q 6 May 21 2021 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2021	May 04, 2021
Document Information [Line Items]
Entity Registrant Name	Avinger Inc
Entity Central Index Key	0001506928
Trading Symbol	avgr
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Interactive Data Current	Yes
Entity Common Stock, Shares Outstanding (in shares)		95,351,502
Entity Shell Company	false
Document Type	10-Q
Document Period End Date	Mar. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false
Title of 12(b) Security	Common Stock, par value $0.001 per share

Condensed Balance Sheets (Curre

Condensed Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 30,448	$ 22,185
Accounts receivable, net of allowance for doubtful accounts of $6 at March 31, 2021 and $19 at December 31, 2020	1,531	1,484
Inventories	3,936	3,876
Prepaid expenses and other current assets	1,318	350
Total current assets	37,233	27,895
Right of use asset	3,848	4,063
Property and equipment, net	552	727
Other assets	476	510
Total assets	42,109	33,195
Current liabilities:
Accounts payable	786	694
Accrued compensation	1,568	1,703
Series A preferred stock dividends payable	1,044
Accrued expenses and other current liabilities	856	669
Leasehold liability, current portion	909	806
Borrowings, current portion	2,072	3,590
Total current liabilities	7,235	7,462
Borrowings, long-term portion	11,316	9,400
Leasehold liability, long-term portion	2,939	3,257
Other long-term liabilities	144
Total liabilities	21,634	20,119
Commitments and contingencies (Note 7)
Stockholders’ equity:
Convertible preferred stock issuable in series, par value of $0.001 Shares authorized: 5,000,000 at March 31, 2021 and December 31, 2020 Shares issued and outstanding: 52,276 and 52,369 at March 31, 2021 and December 31, 2020, respectively; aggregate liquidation preference of $52,276 and $52,369 at March 31, 2021 and December 31, 2020, respectively
Common stock, par value of $0.001; Shares authorized: 100,000,000 at March 31, 2021 and December 31, 2020 Shares issued and outstanding: 95,351,502 and 84,926,129 at March 31, 2021 and December 31, 2020, respectively	95	85
Additional paid-in capital	392,773	380,332
Accumulated deficit	(372,393)	(367,341)
Total stockholders’ equity	20,475	13,076
Total liabilities and stockholders’ equity	$ 42,109	$ 33,195

Condensed Balance Sheets (Cur_2

Condensed Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Accounts receivable, allowance for doubtful accounts	$ 6	$ 19
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)	52,276	52,369
Preferred stock, shares outstanding (in shares)	52,276	52,369
Preferred stock, liquidation preference	$ 52,276	$ 52,369
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)	95,351,502	84,926,129
Common stock, shares outstanding (in shares)	95,351,502	84,926,129

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenues	$ 2,559	$ 2,261
Cost of revenues	1,665	1,760
Gross profit	894	501
Operating expenses:
Research and development	1,598	1,594
Selling, general and administrative	3,945	4,386
Total operating expenses	5,543	5,980
Loss from operations	(4,649)	(5,479)
Interest income	2	30
Interest expense	(398)	(398)
Other expense, net	(7)	(4)
Net loss and comprehensive loss	(5,052)	(5,851)
Accretion of preferred stock dividends	(1,044)	(967)
Net loss applicable to common stockholders	$ (6,096)	$ (6,818)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.07)	$ (0.47)
Weighted average common shares used to compute net loss per share, basic and diluted (in shares)	91,435	14,616

Condensed Statements of Stockho

Condensed Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	August 2019 Public Offering [Member]Preferred Stock [Member]	August 2019 Public Offering [Member]Common Stock [Member]	August 2019 Public Offering [Member]Additional Paid-in Capital [Member]	August 2019 Public Offering [Member]Retained Earnings [Member]	August 2019 Public Offering [Member]	Conversion of Series B Preferred Stock into Common Stock [Member]Preferred Stock [Member]	Conversion of Series B Preferred Stock into Common Stock [Member]Common Stock [Member]	Conversion of Series B Preferred Stock into Common Stock [Member]Additional Paid-in Capital [Member]	Conversion of Series B Preferred Stock into Common Stock [Member]Retained Earnings [Member]	Conversion of Series B Preferred Stock into Common Stock [Member]	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Dec. 31, 2019											48,503	10,364,663
Balance at Dec. 31, 2019												$ 10	$ 355,220	$ (348,335)	$ 6,895
Issuance of common stock in public offerings, net of commissions and issuance costs (in shares)		6,428,572
Issuance of common stock in public offerings, net of commissions and issuance costs		$ 7	$ 3,855		$ 3,862
Issuance of common stock under officers and directors purchase plan and vesting of restricted stock units (in shares)												28,124
Issuance of common stock under officers and directors purchase plan and vesting of restricted stock units													18		18
Employee stock-based compensation													451	451	451
Accretion of Series A preferred stock dividends													(967)		(967)
Net and comprehensive loss														(5,851)	(5,851)
Balance (in shares) at Mar. 31, 2020											48,503	16,821,359
Balance at Mar. 31, 2020												$ 17	358,577	(354,186)	4,408
Balance (in shares) at Dec. 31, 2020											52,369	84,926,129
Balance at Dec. 31, 2020												$ 85	380,332	(367,341)	13,076
Issuance of common stock in public offerings, net of commissions and issuance costs (in shares)		10,000,000
Issuance of common stock in public offerings, net of commissions and issuance costs		$ 10	$ 13,067		$ 13,077
Issuance of common stock under officers and directors purchase plan and vesting of restricted stock units (in shares)												53,373
Issuance of common stock under officers and directors purchase plan and vesting of restricted stock units
Employee stock-based compensation													418	451	418
Accretion of Series A preferred stock dividends													(1,044)		(1,044)
Net and comprehensive loss														(5,052)	(5,052)
Conversion of convertible securities (in shares)						(93)	372,000
Conversion of convertible securities
Balance (in shares) at Mar. 31, 2021											52,276	95,351,502
Balance at Mar. 31, 2021												$ 95	$ 392,773	$ (372,393)	$ 20,475

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities
Net loss	$ (5,052)	$ (5,851)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	194	225
Amortization of debt issuance costs and debt discount	28	43
Stock-based compensation	418	451
Noncash interest expense and other charges	370	356
Change in right of use asset	34	43
Provision for excess and obsolete inventories	7	104
Other non-cash charges	2	(1)
Changes in operating assets and liabilities:
Accounts receivable	(49)	105
Inventories	(67)	(17)
Prepaid expenses and other current assets	(968)	(722)
Other assets		5
Accounts payable	84	722
Accrued compensation	(135)	(476)
Accrued expenses and other current liabilities	187	41
Other long-term liabilities	144	2
Net cash used in operating activities	(4,803)	(4,970)
Cash flows from investing activities
Purchase of property and equipment	(11)
Net cash used in investing activities	(11)
Cash flows from financing activities
Proceeds from the issuance of common stock under officers’ and directors’ purchase plan		27
Proceeds from the issuance of common stock in public offerings, net	13,077	3,862
Net cash provided by financing activities	13,077	3,889
Net change in cash and cash equivalents	8,263	(1,081)
Cash and cash equivalents, beginning of period	22,185	10,943
Cash and cash equivalents, end of period	30,448	9,862
Noncash investing and financing activities:
Accretion of Series A preferred stock dividends	1,044	967
Transfers between inventory and property and equipment		(49)
Reclassification of right of use asset to prepaid rent	$ (34)	$ (43)

Note 1 - Organization

Note 1 - Organization	3 Months Ended
	Mar. 31, 2021
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”) 2, 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, 2021, $372.4 $30.4 March 31, 2021 2022. $3.9 January 2020 $2.3 April 2020 $3.0 April May 2020, $5.5 June July 2020, $11.3 August September 2020, $13.1 February 2021. not may The Company can provide no not may twelve no 19 second 2020 19 20% 20%. July 2020. If the Company is unable to raise additional capital in sufficient amounts or on terms acceptable to it, the Company may one not Public Offerings On January 31, 2020, 6,428,572 $0.70 $3.9 February 2018 $0.70 On April 30, 2020, 12,600,000 $0.25 May 6, 2020 1,890,000 $3.0 February 2018 $0.25 On June 26, 2020, 20,000,000 $0.27 July 9, 2020 3,000,000 $0.7 $5.5 On August 6, 2020, 15,789,474 $0.38 August 11, 2020 2,368,421 $6.2 On August 25, 2020, 11,063,830 $0.47 September 1, 2020 1,000,000 $5.1 On February 2, 2021, 10,000,000 $1.44 $13.1

Note 2 - Summary of Significant

Note 2 - Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
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, 2021 not December 31, 2021, December 31, 2020 10 December 31, 2020, March 11, 2021. 2 10 December 31, 2020. 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, 2021 December 31, 2020. The Company's accounts receivable are due from a variety of healthcare organizations in the United States and select international markets. At March 31, 2021, no one 10% December 31, 2020, one 14% three March 31, 2021 2020, no 10% Product Warranty Costs The Company typically offers a one Three Months Ended March 31, 2021 2020 Beginning balance $ 193 $ 215 Warranty provision 20 61 Usage/Release (2 ) (55 ) Ending balance $ 211 $ 221 Net Loss per Share Attributable to Common Stockholders Basic net loss per share attributable 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 attributable 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, 2021 2020, no Net loss per share attributable to common stockholders was determined as follows (in thousands, except per share data): Three Months Ended March 31, 2021 2020 Net loss attributable to common stockholders $ (6,096 ) $ (6,818 ) Weighted average common stock outstanding, basic and diluted 91,435 14,616 Net loss per share attributable to common stockholders, basic and diluted $ (0.07 ) $ (0.47 ) 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, 2021 2020 Common stock warrants equivalents 2,753,999 2,753,999 Common stock options 6,771 7,267 Convertible preferred stock 52,328 48,503 Unvested restricted stock units 420,856 873,693 3,233,954 3,683,462 Segment and Geographical Information The Company operates and manages its business as one three March 31, 2021 2020, 94% 98%, Recent Accounting Pronouncements Recently adopted accounting standards In December 2019, 2019 12, Income Taxes (Topic 740 January 1, 2021. not Recent accounting standards not In August 2020, 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 2022 not

Note 3 - Fair Value Measurement

Note 3 - Fair Value Measurements	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Fair Value Disclosures [Text Block]	3. The Company measures certain financial assets and liabilities at fair value on a recurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. A three Level 1 Level 2 1 not Level 3 no As of March 31, 2021 December 31, 2020, 1 March 31, 2021 December 31, 2020, no 2 3. no three March 31, 2021.

Note 4 - Inventories

Note 4 - Inventories	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Inventory Disclosure [Text Block]	4. Inventories consisted of the following (in thousands): March 31, December 31, 2021 2020 Raw materials $ 1,153 $ 1,904 Work-in-process 914 180 Finished products 1,869 1,792 Total inventories $ 3,936 $ 3,876

Note 5 - Borrowings

Note 5 - Borrowings	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Debt Disclosure [Text Block]	5. CRG On September 22, 2015, $50 March 29, 2017. $30 September 22, 2015. $10 June 15, 2016 On February 14, 2018, $38 $3.8 On March 2, 2020, No. 3 ● extend the period that the Company can make interest payments in payment in kind (“PIK”) to June 30, 2021; ● lower the Minimum Revenue Covenants to $10 2020, $12 2021, $15 2022; ● insert certain terms to clarify that all fees, including the prepayment premium, are due if the obligations are accelerated; and ● insert a new provision to make clear that to the extent the Company divides its assets/liabilities into divisions, such assets/liabilities will be treated as transferred to a third On May 12, 2020, No. 4 ● grant to the Company the right to optionally prepay in whole or in part the outstanding principal amount of the Loans for the Redemption Price, subject to certain conditions; and ● waive the Company's requirement to comply with the Minimum Revenue Covenant for 2020. On January 22, 2021, No. 5 ● extend the maturity date of the Loan Agreement from June 30, 2023 December 31, 2025; ● extend the interest only payment period and the period that the Company can make interest payments in PIK to December 31, 2023; ● lower the Minimum Revenue Covenants to $8 $10 2021 2022, $12 2023; $14.5 2024, $17 2025; ● change the date under the on-going stand-alone representation regarding no December 31, 2020; ● amend the on-going stand-alone representation and stand-alone event of default regarding “Material Adverse Change” such that any adverse change in or effect upon the revenue of the Company and its subsidiaries due to the outbreak of COVID- 19 not Under the amended Loan Agreement, no first 2024. not 12.5%. first 2024, $1.9 $7.5 2024, $7.5 2025. December 31, 3025. The Company may 5.0% 1.0% no seven 1.5% 15.0% 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 2.0 may As of March 31, 2021, As of March 31, 2021, Year Ending December 31, 2021 (remaining nine months of the year) $ — 2022 — 2023 — 2024 9,045 2025 10,339 19,384 Less: Amount of PIK additions and final facility fee to be incurred subsequent to March 31, 2021 (7,956 ) Less: Amount representing debt financing costs (391 ) Borrowings, as of March 31, 2021 $ 11,037 In connection with drawdowns under the Loan Agreement, the Company recorded aggregate debt discounts of $1.3 March 31, 2021 December 31, 2020, $391,000 $418,000, $38,000 $43,000 three March 31, 2021 2020, three March 31, 2021 2020, $393,000 $398,000, As of March 31, 2021, $83,000 $308,000 Paycheck Protection Program On April 23, 2020, $2.3 The Loan, which was in the form of a promissory note, dated April 20, 2020 ( April 20, 2022 1% six may no As previously disclosed, the PPP was administered by 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. For the quarter ended March 31, 2021, $6,000 March 31, 2021, $2.2 $0.2

Note 6 - Leases

Note 6 - Leases	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Lessee, Operating Leases [Text Block]	6. 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. $5.8 November 2024, December 1, 2019. March 31, 2021 3.7 The operating lease is included on the balance sheet at the present value of the future base payments discounted at a 6.5% For the three March 31, 2021, $105,000. three March 31, 2021 2020 $ 314,000. three March 31, 2021 2020 $249,000 $236,000, $257,000 March 31, 2021. The following table presents the future operating lease payments and lease liability included on the balance sheet related to the Company's operating lease as of March 31, 2021 ( Year Ending December 31, 2021 (remaining nine months of the year) $ 843 2022 1,162 2023 1,203 2024 1,138 Total 4,346 Less: Imputed interest (498 ) Leasehold liability as of March 31, 2021 $ 3,848

Note 7 - Commitments and Contin

Note 7 - Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	7. 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 $0.9 March 31, 2021. Indemnification In the normal course of business, the Company enters into contracts and agreements that contain a variety of representations and warranties and may may not not The Company indemnifies each of its directors and officers for certain events or occurrences, subject to certain limits, while the director is or was serving at the Company's request in such capacity, as permitted under Delaware law and in accordance with its certificate of incorporation and bylaws. The term of the indemnification period lasts as long as a director may may not Legal Proceedings We are not may

Note 8 - Stockholders' Equity

Note 8 - Stockholders' Equity	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Stockholders' Equity Note Disclosure [Text Block]	8. Equity Convertible Preferred Stock As of March 31, 2021, 5,000,000 $0.001 52,276 Series A Convertible Preferred Stock On February 14, 2018, $38.0 $3.8 $41.8 2,090,000 8%, no January 2019, December 2019 December 2020, 2,945, 3,580 3,866 December 31, 2020. March 31, 2021, 52,191 $1.0 $967,000 March 31, 2021 2020, Series B Convertible Preferred Stock On February 16, 2018, 17,979 $15.5 $0.001 no no not December 31, 2019, 1,523 380,750 March 31, 2021, 93 372,000 March 31, 2021 December 31, 2020, 85 178 $ 0.25 Series C Convertible Preferred Stock On November 1, 2018, 728,500 8,586 $10.2 $0.001 no December 31, 2019, 2,170 542,500 no Common Stock As of March 31, 2021, 100,000,000 $0.001 95,351,502 Common Stock Warrants As of March 31, 2021 December 31, 2020, Total Outstanding and Exercisable Underlying Shares of Common Stock Exercise Price per Share Expiration Date Series 1 Warrants issued in February 2018 Series B financing 8,979,000 897,900 $ 20.00 February 2025 Series 2 Warrants issued in February 2018 Series B financing 8,709,500 870,950 $ 20.00 February 2025 Warrants issued in July 2018 financing 1,083,091 108,309 $ 15.80 July 2021 Warrants issued in November 2018 financing 8,768,395 876,840 $ 4.00 November 2023 Total 27,539,986 2,753,999 As of March 31, 2021 December 31, 2020, 2,753,999 Stock Plans In January 2015, 2015 “2015 March 31, 2021, 135,048 2015 Stock option activity under the Plans is set forth below: Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (in years) Intrinsic Value (in thousands) Balance at December 31, 2020 6,821 $ 1,241.59 5.81 $ — Granted — — Exercised — — Expired (74 ) 2,821.62 Forfeited — — Balance at March 31, 2021 6,747 $ 1,224.26 5.62 $ — Exercisable at March 31, 2021 6,747 $ 1,224.26 5.62 $ — Vested and expected to vest at March 31, 2021 6,747 $ 1,224.26 5.62 $ — There were no three March 31, 2021 2020. three March 31, 2021 2020, $4,000 $33,000, March 31, 2021, no not three March 31, 2021 2020. The Company measures the fair value of RSUs using the closing stock price of a share of the Company's common stock on the grant date and is recognized as expense on a straight-line basis over the vesting period of the award. A summary of all RSU activity is presented below: Number of Shares Weighted Average Grant Date Fair Value Weighted Average Remaining Contractual Term Awards outstanding at December 31, 2020 412,642 $ 3.84 0.98 Awarded 90,000 $ 1.61 — Released (53,373 ) $ 2.44 — Forfeited — $ — — Awards outstanding at March 31, 2021 449,269 $ 3.56 0.86 As of March 31, 2021, $0.8 0.9 449,269 $0.7 $1.51 March 31, 2021, three March 31, 2021 2020, $87,000 $38, three March 31, 2021 2020, $0.4 2018 On August 22, 2018, may 20,000 August 28, 2019 March 10, 2020, 40,000 125,000 no three March 31, 2021. March 31, 2021, 92,170

Note 9 - Stock-based Compensati

Note 9 - Stock-based Compensation	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Share-based Payment Arrangement [Text Block]	9. Total noncash stock-based compensation expense relating to the Company's stock options and RSUs recognized during the three March 31, 2021 2020, Three Months Ended March 31, 2021 2020 Cost of revenues $ 34 $ 34 Research and development expenses 111 132 Selling, general and administrative expenses 273 285 $ 418 $ 451

Note 10 - Subsequent Events

Note 10 - Subsequent Events	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Subsequent Events [Text Block]	10. As previously disclosed, on April 23, 2020, $2.3 December 2020. On April 17, 2021, no

Significant Accounting Policies

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
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, 2021 not December 31, 2021, December 31, 2020 10 December 31, 2020, March 11, 2021. 2 10 December 31, 2020.
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, 2021 December 31, 2020. The Company's accounts receivable are due from a variety of healthcare organizations in the United States and select international markets. At March 31, 2021, no one 10% December 31, 2020, one 14% three March 31, 2021 2020, no 10%
Standard Product Warranty, Policy [Policy Text Block]	Product Warranty Costs The Company typically offers a one Three Months Ended March 31, 2021 2020 Beginning balance $ 193 $ 215 Warranty provision 20 61 Usage/Release (2 ) (55 ) Ending balance $ 211 $ 221
Earnings Per Share, Policy [Policy Text Block]	Net Loss per Share Attributable to Common Stockholders Basic net loss per share attributable 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 attributable 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, 2021 2020, no Net loss per share attributable to common stockholders was determined as follows (in thousands, except per share data): Three Months Ended March 31, 2021 2020 Net loss attributable to common stockholders $ (6,096 ) $ (6,818 ) Weighted average common stock outstanding, basic and diluted 91,435 14,616 Net loss per share attributable to common stockholders, basic and diluted $ (0.07 ) $ (0.47 ) 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, 2021 2020 Common stock warrants equivalents 2,753,999 2,753,999 Common stock options 6,771 7,267 Convertible preferred stock 52,328 48,503 Unvested restricted stock units 420,856 873,693 3,233,954 3,683,462
Segment Reporting, Policy [Policy Text Block]	Segment and Geographical Information The Company operates and manages its business as one three March 31, 2021 2020, 94% 98%,
New Accounting Pronouncements, Policy [Policy Text Block]	Recent Accounting Pronouncements Recently adopted accounting standards In December 2019, 2019 12, Income Taxes (Topic 740 January 1, 2021. not Recent accounting standards not In August 2020, 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 2022 not

Note 2 - Summary of Significa_2

Note 2 - Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Product Warranty Liability [Table Text Block]	Three Months Ended March 31, 2021 2020 Beginning balance $ 193 $ 215 Warranty provision 20 61 Usage/Release (2 ) (55 ) Ending balance $ 211 $ 221
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	Three Months Ended March 31, 2021 2020 Net loss attributable to common stockholders $ (6,096 ) $ (6,818 ) Weighted average common stock outstanding, basic and diluted 91,435 14,616 Net loss per share attributable to common stockholders, basic and diluted $ (0.07 ) $ (0.47 )
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	Three Months Ended March 31, 2021 2020 Common stock warrants equivalents 2,753,999 2,753,999 Common stock options 6,771 7,267 Convertible preferred stock 52,328 48,503 Unvested restricted stock units 420,856 873,693 3,233,954 3,683,462

Note 4 - Inventories (Tables)

Note 4 - Inventories (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Inventory, Current [Table Text Block]	March 31, December 31, 2021 2020 Raw materials $ 1,153 $ 1,904 Work-in-process 914 180 Finished products 1,869 1,792 Total inventories $ 3,936 $ 3,876

Note 5 - Borrowings (Tables)

Note 5 - Borrowings (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Debt [Table Text Block]	Year Ending December 31, 2021 (remaining nine months of the year) $ — 2022 — 2023 — 2024 9,045 2025 10,339 19,384 Less: Amount of PIK additions and final facility fee to be incurred subsequent to March 31, 2021 (7,956 ) Less: Amount representing debt financing costs (391 ) Borrowings, as of March 31, 2021 $ 11,037

Note 6 - Leases (Tables)

Note 6 - Leases (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	Year Ending December 31, 2021 (remaining nine months of the year) $ 843 2022 1,162 2023 1,203 2024 1,138 Total 4,346 Less: Imputed interest (498 ) Leasehold liability as of March 31, 2021 $ 3,848

Note 8 - Stockholders' Equity (

Note 8 - Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2021
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 February 2018 Series B financing 8,979,000 897,900 $ 20.00 February 2025 Series 2 Warrants issued in February 2018 Series B financing 8,709,500 870,950 $ 20.00 February 2025 Warrants issued in July 2018 financing 1,083,091 108,309 $ 15.80 July 2021 Warrants issued in November 2018 financing 8,768,395 876,840 $ 4.00 November 2023 Total 27,539,986 2,753,999
Share-based Payment Arrangement, Option, Activity [Table Text Block]	Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (in years) Intrinsic Value (in thousands) Balance at December 31, 2020 6,821 $ 1,241.59 5.81 $ — Granted — — Exercised — — Expired (74 ) 2,821.62 Forfeited — — Balance at March 31, 2021 6,747 $ 1,224.26 5.62 $ — Exercisable at March 31, 2021 6,747 $ 1,224.26 5.62 $ — Vested and expected to vest at March 31, 2021 6,747 $ 1,224.26 5.62 $ —
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, 2020 412,642 $ 3.84 0.98 Awarded 90,000 $ 1.61 — Released (53,373 ) $ 2.44 — Forfeited — $ — — Awards outstanding at March 31, 2021 449,269 $ 3.56 0.86

Note 9 - Stock-based Compensa_2

Note 9 - Stock-based Compensation (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]	Three Months Ended March 31, 2021 2020 Cost of revenues $ 34 $ 34 Research and development expenses 111 132 Selling, general and administrative expenses 273 285 $ 418 $ 451

Note 1 - Organization (Details

Note 1 - Organization (Details Textual) - USD ($)

Feb. 02, 2021

Sep. 01, 2020

Aug. 25, 2020

Aug. 11, 2020

Aug. 06, 2020

Jul. 09, 2020

Jul. 09, 2020

Jun. 26, 2020

May 06, 2020

Apr. 30, 2020

Apr. 23, 2020

Jan. 31, 2020

Feb. 16, 2018

Feb. 28, 2021

Jan. 31, 2020

Sep. 30, 2020

Jul. 31, 2020

May 31, 2020

Mar. 31, 2021

Dec. 31, 2020

Retained Earnings (Accumulated Deficit), Ending Balance

$ (372,393,000)

$ (367,341,000)

Cash and Cash Equivalents, at Carrying Value, Ending Balance

$ 30,448,000

$ 22,185,000

Proceeds from Issuance or Sale of Equity, Net

$ 15,500,000

Share Price (in dollars per share)

$ 1.51

COVID 19 [Member]

Reduction of Non-manufacturing Employees Salaries

20.00%

Reduction of Hours Worked by Manufacturing Workers, Percentage

20.00%

Paycheck Protection Program CARES Act [Member]

Proceeds from Issuance of Long-term Debt, Total

$ 2,300,000

January 2020 Public Offering [Member]

Proceeds from Issuance or Sale of Equity, Net

$ 3,900,000

$ 3,900,000

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

6,428,572

Share Price (in dollars per share)

$ 0.70

$ 0.70

April and May 2020 Public Offering [Member]

Proceeds from Issuance or Sale of Equity, Net

$ 3,000,000

June and July 2020 Public Offering [Member]

Proceeds from Issuance or Sale of Equity, Net

$ 5,500,000

August and September 2020 Public Offering [Member]

Proceeds from Issuance or Sale of Equity, Net

$ 11,300,000

February 2021 Public Offering [Member]

Proceeds from Issuance or Sale of Equity, Net

$ 13,100,000

$ 13,100,000

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

10,000,000

Share Price (in dollars per share)

$ 1.44

April 2020 Public Offering [Member]

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

12,600,000

Share Price (in dollars per share)

$ 0.25

May 2020 Public Offering [Member]

Proceeds from Issuance or Sale of Equity, Net

$ 3,000,000

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

1,890,000

June 2020 Public Offering [Member]

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

20,000,000

Share Price (in dollars per share)

$ 0.27

July 2020 Public Offering [Member]

Proceeds from Issuance or Sale of Equity, Net

$ 700,000

$ 5,500,000

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

3,000,000

August 2020 Public Offering [Member]

Proceeds from Issuance or Sale of Equity, Net

$ 6,200,000

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

11,063,830

2,368,421

15,789,474

Share Price (in dollars per share)

$ 0.47

$ 0.38

September 2020 Public Offering [Member]

Proceeds from Issuance or Sale of Equity, Net

$ 5,100,000

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

1,000,000

Note 2 - Summary of Significa_3

Note 2 - Summary of Significant Accounting Policies (Details Textual) shares in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021shares	Mar. 31, 2020shares	Dec. 31, 2020
Weighted Average Number of Shares, Common Stock Subject to Repurchase or Cancellation (in shares)	0	0
Number of Reportable Segments	1
Customer Concentration Risk [Member] | Accounts Receivable [Member]
Number of Major Customers	0		1
Customer Concentration Risk [Member] | Accounts Receivable [Member] | One Customer [Member]
Concentration Risk, Percentage			14.00%
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | UNITED STATES
Concentration Risk, Percentage	94.00%	98.00%

Note 2 - Summary of Significa_4

Note 2 - Summary of Significant Accounting Policies - Product Warranty (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Beginning balance	$ 193	$ 215
Warranty provision	20	61
Usage/Release	(2)	(55)
Ending balance	$ 211	$ 221

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, 2021	Mar. 31, 2020
Net loss attributable to common stockholders	$ (6,096)	$ (6,818)
Weighted average common stock outstanding, basic and diluted (in shares)	91,435	14,616
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.07)	$ (0.47)

Note 2 - Summary of Significa_6

Note 2 - Summary of Significant Accounting Policies - Anti-dilutive Securities (Details) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Antidilutive Securities (in shares)	3,233,954	3,683,462
Common Stock Warrants [Member]
Antidilutive Securities (in shares)	2,753,999	2,753,999
Common Stock Options [ member]
Antidilutive Securities (in shares)	6,771	7,267
Preferred Stock [Member]
Antidilutive Securities (in shares)	52,328	48,503
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities (in shares)	420,856	873,693

Note 3 - Fair Value Measureme_2

Note 3 - Fair Value Measurements (Details Textual) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure		$ 0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	$ 0
Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure		$ 0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	$ 0

Note 4 - Inventories - Schedule

Note 4 - Inventories - Schedule of Inventory (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Raw materials	$ 1,153	$ 1,904
Work-in-process	914	180
Finished products	1,869	1,792
Total inventories	$ 3,936	$ 3,876

Note 5 - Borrowings (Details Te

Note 5 - Borrowings (Details Textual)	Jan. 22, 2021USD ($)	Apr. 23, 2020USD ($)	Feb. 14, 2018USD ($)	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)	Apr. 17, 2021USD ($)	Dec. 31, 2020USD ($)	Mar. 02, 2020USD ($)	Jun. 15, 2016USD ($)	Sep. 22, 2015USD ($)
Interest Expense, Total				$ 398,000	$ 398,000
Paycheck Protection Program CARES Act [Member]
Proceeds from Issuance of Long-term Debt, Total		$ 2,300,000
Interest Expense, Total				6,000
Paycheck Protection Program CARES Act [Member] | Subsequent Event [Member]
Long-term Debt, Total						$ 0
CRG [Member] | Loan Agreement [Member]
Debt Agreement, Maximum Borrowing Capacity										$ 50,000,000
Debt Instrument, Covenant Compliance Target Minimum Revenue, Next Twelve Months	$ 8,000,000							$ 10,000,000
Debt Instrument, Covenant, Compliance Target Minimum Revenue Second Year	10,000,000							12,000,000
Debt Instrument, Covenant Compliance Target Minimum Revenue Third Year	12,000,000							$ 15,000,000
Debt Instrument, Covenant Compliance Target Minimum Revenue Fourth Year	14,500,000
Debt Instrument, Covenant Compliance Target Minimum Revenue Fifth 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				391,000			$ 418,000			1,300,000
Amortization of Debt Discount (Premium)				38,000	43,000
Interest Expense, Debt, Total				393,000	$ 398,000
Debt Instrument, Unamortized Discount, Current				83,000
Debt Instrument, Unamortized Discount, Noncurrent				308,000
Long-term Debt, Current Maturities, Total				2,200,000
Long-term Debt, Excluding Current Maturities, Total				$ 200,000
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 5 - Borrowings - Schedule

Note 5 - Borrowings - Schedule of Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Borrowings, as of March 31, 2021	$ 2,072	$ 3,590
Loan Agreement [Member] | CRG [Member]
2021 (remaining nine months of the year)
2022
2023
2024	9,045
Long-Term Debt, Maturity, Year Four	10,339
Long-term Debt, Total	19,384
Less: Amount of PIK additions and final facility fee to be incurred subsequent to March 31, 2021	(7,956)
Less: Amount representing debt financing costs	(391)
Borrowings, as of March 31, 2021	$ 11,037

Note 6 - Leases (Details Textua

Note 6 - Leases (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Apr. 01, 2019
Lessee, Operating Lease, Liability, Payments, Due, Total	$ 4,346,000		$ 5,800,000
Operating Lease, Weighted Average Remaining Lease Term (Year)	3 years 255 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
Operating Lease, Right-of-Use Asset, Amortization Expense	249,000	$ 236,000
Prepaid Rent	$ 257,000

Note 6 - Leases - Future Operat

Note 6 - Leases - Future Operating Lease Payments (Details) - USD ($)	Mar. 31, 2021	Apr. 01, 2019
2021 (remaining nine months of the year)	$ 843,000
2022	1,162,000
2023	1,203,000
2024	1,138,000
Total	4,346,000	$ 5,800,000
Less: Imputed interest	(498,000)
Leasehold liability as of March 31, 2021	$ 3,848,000

Note 7 - Commitments and Cont_2

Note 7 - Commitments and Contingencies (Details Textual) $ in Millions	Mar. 31, 2021USD ($)
Purchase Commitment [Member]
Purchase Obligation, Total	$ 0.9

Note 8 - Stockholders' Equity_2

Note 8 - Stockholders' Equity (Details Textual) - USD ($)	Nov. 01, 2018	Feb. 16, 2018	Feb. 14, 2018	Dec. 31, 2020	Dec. 31, 2019	Jan. 31, 2019	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Mar. 10, 2020	Aug. 28, 2019	Aug. 22, 2018	Jan. 31, 2015
Preferred Stock, Shares Authorized (in shares)				5,000,000			5,000,000		5,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share)				$ 0.001			$ 0.001		$ 0.001
Preferred Stock, Shares Issued, Total (in shares)				52,369			52,276		52,369
Preferred Stock, Shares Outstanding, Ending Balance (in shares)				52,369			52,276		52,369
Proceeds from Issuance or Sale of Equity, Net		$ 15,500,000
Common Stock, Shares Authorized (in shares)				100,000,000			100,000,000		100,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share)				$ 0.001			$ 0.001		$ 0.001
Common Stock, Shares, Issued, Total (in shares)				84,926,129			95,351,502		84,926,129
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				2,753,999			2,753,999		2,753,999
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)							0	0
Share-based Payment Arrangement, Expense, Tax Benefit							$ 0	$ 0
Share Price (in dollars per share)							$ 1.51
Share-based Payment Arrangement, Expense							$ 418,000	$ 451,000
Common Stock, Shares, Outstanding, Ending Balance (in shares)				84,926,129			95,351,502		84,926,129
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares)							0
Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)							4,000	33,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total							$ 0
Restricted Stock Units (RSUs) [Member]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total							$ 800,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)							328 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance (in shares)				412,642			449,269		412,642
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Fair Value							$ 700,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value							87,000	$ 38
Share-based Payment Arrangement, Expense							$ 400,000	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)							135,048
Officer and Director Share Purchase Plan [Member]
Common Stock, Shares, Issued, Total (in shares)							0
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares)							92,170
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)											125,000	40,000	20,000
Common Stock Warrants, Issued with Series E Convertible Preferred Stock [Member]
Class of Warrant or Right, Securities Called as Percentage of Convertible Preferred Stock Shares														13.00%
Common Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)	728,500
Conversion of Series B Preferred Stock into Common Stock [Member]
Conversion of Stock, Shares Converted (in shares)							93			1,523
Conversion of Stock, Shares Issued (in shares)							372,000			380,750
Conversion of Series C Preferred Stock into Common Stock [Member]
Conversion of Stock, Shares Issued (in shares)										542,500
Series A Preferred Stock [Member]
Preferred Stock, Shares Outstanding, Ending Balance (in shares)							52,191
Dividends, Preferred Stock, Total							$ 1,000,000	$ 967,000
Series A Preferred Stock [Member] | CRG [Member]
Preferred Stock Dividends, Shares (in shares)				3,866	3,580	2,945
Series B Preferred Stock [Member]
Preferred Stock, Par or Stated Value Per Share (in dollars per share)		$ 0.001
Preferred Stock, Shares Outstanding, Ending Balance (in shares)				178			85		178
Stock Issued During Period, Shares, New Issues (in shares)		17,979
Preferred Stock, Convertible, Conversion Price (in dollars per share)							$ 0.25		$ 0.25
Series C Preferred Stock [Member]
Preferred Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.001
Preferred Stock, Shares Outstanding, Ending Balance (in shares)					2,170					2,170
Stock Issued During Period, Shares, New Issues (in shares)	8,586
Proceeds from Issuance or Sale of Equity, Net	$ 10,200,000
Conversion of Principal Amount of Senior Secured Loan to Newly Authorized Series A Preferred Stock [Member] | Series A Preferred Stock [Member]
Convertible Preferred Stock, Shares of Common Stock Issuable on Conversion (in shares)			2,090,000
Preferred Stock, Dividend Rate, Percentage			8.00%
CRG [Member] | Conversion of Principal Amount of Senior Secured Loan to Newly Authorized Series A Preferred Stock [Member]
Debt Conversion, Original Debt, Amount			$ 38,000,000
Debt Conversion, Fees and Prepayment Premium Amount			3,800,000
Debt Conversion, Converted Instrument, Amount			$ 41,800,000

Note 8 - Stockholder's Equity -

Note 8 - Stockholder's Equity - Outstanding Warrants (Details) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Total outstanding and exercisable (in shares)	27,539,986
Underlying shares of common stock (in shares)	2,753,999	2,753,999
Series 1 February 2018 Warrants [Member]
Total outstanding and exercisable (in shares)	8,979,000
Underlying shares of common stock (in shares)	897,900
Exercise price per share (in dollars per share)	$ 20
Series 2 February 2018 Warrants [Member]
Total outstanding and exercisable (in shares)	8,709,500
Underlying shares of common stock (in shares)	870,950
Exercise price per share (in dollars per share)	$ 20
November 2018 Warrants [Member]
Total outstanding and exercisable (in shares)	1,083,091
Underlying shares of common stock (in shares)	108,309
Exercise price per share (in dollars per share)	$ 15.80
July 2018 Warrants [Member]
Total outstanding and exercisable (in shares)	8,768,395
Underlying shares of common stock (in shares)	876,840
Exercise price per share (in dollars per share)	$ 4

Note 8 - Stockholders' Equity -

Note 8 - Stockholders' Equity - Stock Option Activity (Details) - $ / shares shares in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Options (in shares)	6,821
Options, weighted average exercise price (in dollars per share)	$ 1,241.59
Options, weighted average remaining contractual life (Year)	5 years 226 days	5 years 295 days
Expired (in shares)	(74)
Expired, weighted average exercise price (in dollars per share)	$ 2,821,620
Options (in shares)	6,747	6,821
Options, weighted average exercise price (in dollars per share)	$ 1,224.26	$ 1,241.59
Exercisable (in shares)	6,747
Exercisable, weighted average exercise price (in dollars per share)	$ 1,224.26
Exercisable, weighted average remaining contractual life (Year)	5 years 226 days
Vested and expected to vest (in shares)	6,747
Vested and expected to vest, weighted average exercise price (in dollars per share)	$ 1,224.26
Vested and expected to vest, weighted average remaining contractual life (Year)	5 years 226 days

Note 8 - Stockholders' Equity_3

Note 8 - Stockholders' Equity - Restricted Stock Units Award Activity (Details) - Restricted Stock Units (RSUs) [Member] - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Awards outstanding, Shares (in shares)	412,642
Awards outstanding, Weighted grant date fair value (in dollars per share)	$ 3.84
Awards outstanding, Weighted average remaining contractual term (Year)	313 days	357 days
Awarded, Shares (in shares)	90,000
Awarded, Weighted grant date fair value (in dollars per share)	$ 1.61
Released, Shares (in shares)	(53,373)
Released, Weighted grant date fair value (in dollars per share)	$ 2.44
Forfeited, Shares (in shares)
Forfeited, Weighted grant date fair value (in dollars per share)
Awards outstanding, Shares (in shares)	449,269	412,642
Awards outstanding, Weighted grant date fair value (in dollars per share)	$ 3.56	$ 3.84

Note 9 - Stock-based Compensa_3

Note 9 - Stock-based Compensation - Noncash Stock-based Compensation Expense Related to Stock Options, ESPP, and RSUs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Allocated Share-based Compensation Expense	$ 418	$ 451
Cost of Sales [Member]
Allocated Share-based Compensation Expense	34	34
Research and Development Expense [Member]
Allocated Share-based Compensation Expense	111	132
Selling, General and Administrative Expenses [Member]
Allocated Share-based Compensation Expense	$ 273	$ 285

Note 10 - Subsequent Events (De

Note 10 - Subsequent Events (Details Textual) - Paycheck Protection Program CARES Act [Member] - USD ($)	Apr. 23, 2020	Apr. 17, 2021
Proceeds from Issuance of Long-term Debt, Total	$ 2,300,000
Subsequent Event [Member]
Long-term Debt, Total		$ 0