Avinger (AVGR) 10-Q 10 Aug 21 2021 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2021	Jul. 30, 2021
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	Q2
Document Fiscal Year Focus	2021
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
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		95,353,002

Condensed Balance Sheets (Curre

Condensed Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 26,700	$ 22,185
Accounts receivable, net of allowance for doubtful accounts of $6 at June 30, 2021 and $19 at December 31, 2020	1,788	1,484
Inventories	4,118	3,876
Prepaid expenses and other current assets	1,112	350
Total current assets	33,718	27,895
Right of use asset	3,630	4,063
Property and equipment, net	355	727
Other assets	486	510
Total assets	38,189	33,195
Current liabilities:
Accounts payable	1,037	694
Accrued compensation	1,667	1,703
Series A preferred stock dividends payable	2,088	0
Accrued expenses and other current liabilities	764	669
Leasehold liability, current portion	934	806
Borrowings, current portion	0	3,590
Total current liabilities	6,490	7,462
Borrowings, long-term portion	11,434	9,400
Leasehold liability, long-term portion	2,696	3,257
Other long-term liabilities	287	0
Total liabilities	20,907	20,119
Commitments and contingencies (Note 7)
Stockholders’ equity:
Convertible preferred stock issuable in series, par value of $0.001; Aggregate shares authorized: 5,000,000 at June 30, 2021 and December 31, 2020; Aggregate shares issued and outstanding: 52,276 and 52,369 at June 30, 2021 and December 31, 2020, respectively; aggregate liquidation preference of $52,191 at both June 30, 2021 and December 31, 2020 (Note 8)	0	0
Common stock, par value of $0.001; Shares authorized: 100,000,000 at June 30, 2021 and December 31, 2020; Shares issued and outstanding: 95,353,002 and 84,926,129 at June 30, 2021 and December 31, 2020, respectively	95	85
Additional paid-in capital	392,032	380,332
Accumulated deficit	(374,845)	(367,341)
Total stockholders’ equity	17,282	13,076
Total liabilities and stockholders’ equity	$ 38,189	$ 33,195

Condensed Balance Sheets (Cur_2

Condensed Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 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	$ 52,191	$ 52,191
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)	95,353,002	84,926,129
Common stock, shares outstanding (in shares)	95,353,002	84,926,129

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues	$ 2,802	$ 1,466	$ 5,361	$ 3,727
Cost of revenues	1,784	1,107	3,449	2,867
Gross profit	1,018	359	1,912	860
Operating expenses:
Research and development	1,507	1,297	3,105	2,891
Selling, general and administrative	3,918	2,654	7,863	7,040
Total operating expenses	5,425	3,951	10,968	9,931
Loss from operations	(4,407)	(3,592)	(9,056)	(9,071)
Interest income	1	2	3	32
Interest expense	(400)	(414)	(798)	(812)
Other income, net	2,354	4	2,347	0
Net loss and comprehensive loss	(2,452)	(4,000)	(7,504)	(9,851)
Accretion of preferred stock dividends	(1,044)	(967)	(2,088)	(1,934)
Net loss applicable to common stockholders	$ (3,496)	$ (4,967)	$ (9,592)	$ (11,785)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.04)	$ (0.18)	$ (0.10)	$ (0.56)
Weighted average common shares used to compute net loss per share, basic and diluted (in shares)	95,352	27,310	93,404	20,963

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]	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						$ 0	$ 10	$ 355,220	$ (348,335)	$ 6,895
Issuance of common stock in public offerings, net of commissions and issuance costs (in shares)	0	40,918,572
Issuance of common stock in public offerings, net of commissions and issuance costs	$ 0	$ 41	$ 11,595	$ 0	$ 11,636
Issuance of common stock under officers and directors purchase plan and vesting of restricted stock units (in shares)						0	55,789
Issuance of common stock under officers and directors purchase plan and vesting of restricted stock units						$ 0	$ 0	27	0	27
Employee stock-based compensation						0	0	776	0	776
Accretion of Series A preferred stock dividends						0	0	(1,934)	0	(1,934)
Net and comprehensive loss						$ 0	$ 0	0	(9,851)	(9,851)
Balance (in shares) at Jun. 30, 2020						48,503	51,339,024
Balance at Jun. 30, 2020						$ 0	$ 51	365,684	(358,186)	7,549
Balance (in shares) at Mar. 31, 2020						48,503	16,821,359
Balance at Mar. 31, 2020						$ 0	$ 17	358,577	(354,186)	4,408
Issuance of common stock in public offerings, net of commissions and issuance costs (in shares)	0	34,490,000
Issuance of common stock in public offerings, net of commissions and issuance costs	$ 0	$ 34	7,740	0	7,774
Issuance of common stock under officers and directors purchase plan and vesting of restricted stock units (in shares)						0	27,665
Issuance of common stock under officers and directors purchase plan and vesting of restricted stock units						$ 0	$ 0	9	0	9
Employee stock-based compensation						0	0	325	0	325
Accretion of Series A preferred stock dividends						0	0	(967)	0	(967)
Net and comprehensive loss						$ 0	$ 0	0	(4,000)	(4,000)
Balance (in shares) at Jun. 30, 2020						48,503	51,339,024
Balance at Jun. 30, 2020						$ 0	$ 51	365,684	(358,186)	7,549
Balance (in shares) at Dec. 31, 2020						52,369	84,926,129
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	10,000,000
Issuance of common stock in public offerings, net of commissions and issuance costs	$ 0	$ 10	$ 13,067	$ 0	$ 13,077
Issuance of common stock under officers and directors purchase plan and vesting of restricted stock units (in shares)						0	54,873
Issuance of common stock under officers and directors purchase plan and vesting of restricted stock units						$ 0	$ 0	0	0	0
Employee stock-based compensation						0	0	721	0	721
Accretion of Series A preferred stock dividends						0	0	(2,088)	0	(2,088)
Net and comprehensive loss						$ 0	$ 0	0	(7,504)	(7,504)
Conversion of Series B preferred stock into common stock (in shares)						(93)	372,000
Conversion of Series B preferred stock into common stock						$ 0	$ 0	0	0	0
Balance (in shares) at Jun. 30, 2021						52,276	95,353,002
Balance at Jun. 30, 2021						$ 0	$ 95	392,032	(374,845)	17,282
Balance (in shares) at Mar. 31, 2021						52,276	95,351,502
Balance at Mar. 31, 2021						$ 0	$ 95	392,773	(372,393)	20,475
Issuance of common stock under officers and directors purchase plan and vesting of restricted stock units (in shares)						0	1,500
Issuance of common stock under officers and directors purchase plan and vesting of restricted stock units						$ 0	$ 0	0	0	0
Employee stock-based compensation						0	0	303	0	303
Accretion of Series A preferred stock dividends						0	0	(1,044)	0	(1,044)
Net and comprehensive loss						$ 0	$ 0	0	(2,452)	(2,452)
Balance (in shares) at Jun. 30, 2021						52,276	95,353,002
Balance at Jun. 30, 2021						$ 0	$ 95	$ 392,032	$ (374,845)	$ 17,282

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities
Net loss	$ (7,504)	$ (9,851)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	367	453
Amortization of debt issuance costs and debt discount	44	84
Stock-based compensation	721	776
Noncash interest expense and other charges	753	728
Change in right of use asset	68	86
Provision for excess and obsolete inventories	22	253
Other non-cash charges	10	(29)
Gain on extinguishment of debt	(2,353)	0
Changes in operating assets and liabilities:
Accounts receivable	(314)	382
Inventories	(241)	(465)
Prepaid expenses and other current assets	(762)	(532)
Other assets	(44)	4
Accounts payable	343	261
Accrued compensation	(36)	(631)
Accrued expenses and other current liabilities	95	76
Other long-term liabilities	287	10
Net cash used in operating activities	(8,544)	(8,395)
Cash flows from investing activities
Purchase of property and equipment	(18)	0
Net cash used in investing activities	(18)	0
Cash flows from financing activities
Proceeds from borrowings, net of issuance costs	0	2,330
Proceeds from the issuance of common stock in public offerings, net	13,077	11,636
Proceeds from the issuance of common stock under officers’ and directors’ purchase plan	0	36
Net cash provided by financing activities	13,077	14,002
Net change in cash and cash equivalents	4,515	5,607
Cash and cash equivalents, beginning of period	22,185	10,943
Cash and cash equivalents, end of period	26,700	16,550
Noncash investing and financing activities:
Accretion of Series A preferred stock dividends	2,088	1,934
Reclassification of right of use asset to prepaid rent	(68)	(86)
Transfers between inventory and property and equipment	$ (23)	$ (32)

Note 1 - Organization

Note 1 - Organization	6 Months Ended
	Jun. 30, 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”) Kittycat2, Liquidity Matters In the course of its activities, the Company has incurred losses and negative cash flows from operations since its inception. As of June 30, 2021, June 30, 2021 2022. January 2020 April 2020 April May 2020, June July 2020, August September 2020, February 2021. not may The Company can provide no not may twelve no 19 second 2020 19 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, February 2018 $0.70 On April 30, 2020, May 6, 2020 February 2018 $0.25 On June 26, 2020, July 9, 2020 On August 6, 2020, August 11, 2020 On August 25, 2020, September 1, 2020 On February 2, 2021,

Note 2 - Summary of Significant

Note 2 - Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 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 six June 30, 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 The Company provides for uncollectible amounts when specific credit problems arise. Management’s estimates for uncollectible amounts have been adequate, and management believes that all significant credit risks have been identified at June 30, 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 June 30, 2021 December 31, 2020, one three six June 30, 2021 2020, no 10% Product Warranty Costs The Company typically offers a one Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Beginning balance $ 211 $ 221 $ 193 $ 215 Warranty provision 21 50 41 111 Usage/Release (1 ) (50 ) (3 ) (105 ) Ending balance $ 231 $ 221 $ 231 $ 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 June 30, 2021 2020, no Net loss per share attributable to common stockholders was determined as follows (in thousands, except per share data): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Net loss applicable to common stockholders $ (3,496 ) $ (4,967 ) $ (9,592 ) $ (11,785 ) Weighted average common stock outstanding, basic and diluted 95,352 27,310 93,404 20,963 Net loss per share attributable to common stockholders, basic and diluted $ (0.04 ) $ (0.18 ) $ (0.10 ) $ (0.56 ) 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 June 30, Six Months Ended June 30, 2021 2020 2021 2020 Common stock warrants equivalents 2,753,999 2,753,999 2,753,999 2,753,999 Common stock options 6,739 7,133 6,755 7,200 Convertible preferred stock 52,276 48,503 52,302 48,503 Unvested restricted stock units 422,758 839,804 421,812 856,749 3,235,772 3,649,439 3,234,868 3,666,451 Segment and Geographical Information The Company operates and manages its business as one three June 30, 2021 2020, six June 30, 2021 2020, 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	6 Months Ended
	Jun. 30, 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 Quoted prices in active markets for identical assets or liabilities. Level 2 Inputs other than quoted prices included within Level 1 not Level 3 Unobservable inputs that are supported by little or no As of June 30, 2021 December 31, 2020, 1 June 30, 2021 December 31, 2020, no 2 3. no three June 30, 2021.

Note 4 - Inventories

Note 4 - Inventories	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Inventory Disclosure [Text Block]	4. Inventories consisted of the following (in thousands): June 30, December 31, 2021 2020 Raw materials $ 1,974 $ 1,904 Work-in-process 423 180 Finished products 1,721 1,792 Total inventories $ 4,118 $ 3,876

Note 5 - Borrowings

Note 5 - Borrowings	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Debt Disclosure [Text Block]	5. CRG On September 22, 2015, March 29, 2017. September 22, 2015. June 15, 2016 On February 14, 2018, 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 million for 2020, 2021, 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 million and $10 million for 2021 2022, 2023; 2024, 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 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 June 30, 2021, As of June 30, 2021, Year Ending December 31, 2021 (remaining six 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 June 30, 2021 (7,576 ) Less: Amount representing debt issuance costs (374 ) Borrowings, as of June 30, 2021 $ 11,434 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 June 30, 2021 December 31, 2020, three June 30, 2021 2020, six June 30, 2021 2020, three June 30, 2021 2020, six June 30, 2021 2020, As of June 30, 2021, Paycheck Protection Program On April 23, 2020, 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 three six June 30, 2021, $1,000 three six June 30, 2020,

Note 6 - Leases

Note 6 - Leases	6 Months Ended
	Jun. 30, 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. November 2024, December 1, 2019. June 30, 2021 The operating lease is 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. For the three June 30, 2021, three June 30, 2021 2020 $314,000. six June 30, 2021 2020 $628,000. three June 30, 2021 2020 six June 30, 2021 2020 June 30, 2021. The following table presents the future operating lease payments and lease liability included on the condensed balance sheet related to the Company’s operating lease as of June 30, 2021 ( Year Ending December 31, 2021 (remaining six months of the year) $ 563 2022 1,162 2023 1,203 2024 1,138 4,066 Less: Imputed interest (436 ) Leasehold liability as of June 30, 2021 $ 3,630

Note 7 - Commitments and Contin

Note 7 - Commitments and Contingencies	6 Months Ended
	Jun. 30, 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 $1.3 million as of June 30, 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 The Company is not may

Note 8 - Stockholders' Equity

Note 8 - Stockholders' Equity	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Stockholders' Equity Note Disclosure [Text Block]	8. Equity Convertible Preferred Stock As of June 30, 2021, Series A Convertible Preferred Stock On February 14, 2018, no January 2019, December 2019 December 2020, December 31, 2020. June 30, 2021, June 30, 2021 2020, six June 30, 2021 2020, Series B Convertible Preferred Stock On February 16, 2018, no no not March 31, 2021, June 30, 2021 December 31, 2020, Common Stock As of June 30, 2021, Common Stock Warrants As of June 30, 2021, 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 June 30, 2021 December 31, 2020, July 2021. Stock Plans In January 2015, 2015 “2015 June 30, 2021, 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 (134 ) 2,546.69 Forfeited — — Balance at June 30, 2021 6,687 $ 1,215.43 5.40 $ — Exercisable at June 30, 2021 6,687 $ 1,215.43 5.40 $ — Vested and expected to vest at June 30, 2021 6,687 $ 1,215.43 5.40 $ — There were no options granted or exercised during the six June 30, 2021 2020. three June 30, 2021 2020, six June 30, 2021 2020, June 30, 2021, no not three six June 30, 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 (54,873 ) $ 2.51 Forfeited (27,432 ) $ 2.48 Awards outstanding at June 30, 2021 420,337 $ 3.63 0.78 As of June 30, 2021, June 30, 2021, six June 30, 2021 2020, three June 30, 2021 2020, six June 30, 2021 2020 2018 On August 22, 2018, may August 28, 2019 March 10, 2020, no six June 30, 2021. June 30, 2021,

Note 9 - Stock-based Compensati

Note 9 - Stock-based Compensation	6 Months Ended
	Jun. 30, 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 six June 30, 2021 2020, Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Cost of revenues $ 34 $ 27 $ 68 $ 61 Research and development expenses 84 106 195 238 Selling, general and administrative expenses 185 192 458 477 $ 303 $ 325 $ 721 $ 776

Significant Accounting Policies

Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 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 six June 30, 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 The Company provides for uncollectible amounts when specific credit problems arise. Management’s estimates for uncollectible amounts have been adequate, and management believes that all significant credit risks have been identified at June 30, 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 June 30, 2021 December 31, 2020, one three six June 30, 2021 2020, no 10%
Standard Product Warranty, Policy [Policy Text Block]	Product Warranty Costs The Company typically offers a one Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Beginning balance $ 211 $ 221 $ 193 $ 215 Warranty provision 21 50 41 111 Usage/Release (1 ) (50 ) (3 ) (105 ) Ending balance $ 231 $ 221 $ 231 $ 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 June 30, 2021 2020, no Net loss per share attributable to common stockholders was determined as follows (in thousands, except per share data): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Net loss applicable to common stockholders $ (3,496 ) $ (4,967 ) $ (9,592 ) $ (11,785 ) Weighted average common stock outstanding, basic and diluted 95,352 27,310 93,404 20,963 Net loss per share attributable to common stockholders, basic and diluted $ (0.04 ) $ (0.18 ) $ (0.10 ) $ (0.56 ) 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 June 30, Six Months Ended June 30, 2021 2020 2021 2020 Common stock warrants equivalents 2,753,999 2,753,999 2,753,999 2,753,999 Common stock options 6,739 7,133 6,755 7,200 Convertible preferred stock 52,276 48,503 52,302 48,503 Unvested restricted stock units 422,758 839,804 421,812 856,749 3,235,772 3,649,439 3,234,868 3,666,451
Segment Reporting, Policy [Policy Text Block]	Segment and Geographical Information The Company operates and manages its business as one three June 30, 2021 2020, six June 30, 2021 2020,
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)	6 Months Ended
	Jun. 30, 2021
Notes Tables
Schedule of Product Warranty Liability [Table Text Block]	Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Beginning balance $ 211 $ 221 $ 193 $ 215 Warranty provision 21 50 41 111 Usage/Release (1 ) (50 ) (3 ) (105 ) Ending balance $ 231 $ 221 $ 231 $ 221
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Net loss applicable to common stockholders $ (3,496 ) $ (4,967 ) $ (9,592 ) $ (11,785 ) Weighted average common stock outstanding, basic and diluted 95,352 27,310 93,404 20,963 Net loss per share attributable to common stockholders, basic and diluted $ (0.04 ) $ (0.18 ) $ (0.10 ) $ (0.56 )
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Common stock warrants equivalents 2,753,999 2,753,999 2,753,999 2,753,999 Common stock options 6,739 7,133 6,755 7,200 Convertible preferred stock 52,276 48,503 52,302 48,503 Unvested restricted stock units 422,758 839,804 421,812 856,749 3,235,772 3,649,439 3,234,868 3,666,451

Note 4 - Inventories (Tables)

Note 4 - Inventories (Tables)	6 Months Ended
	Jun. 30, 2021
Notes Tables
Schedule of Inventory, Current [Table Text Block]	June 30, December 31, 2021 2020 Raw materials $ 1,974 $ 1,904 Work-in-process 423 180 Finished products 1,721 1,792 Total inventories $ 4,118 $ 3,876

Note 5 - Borrowings (Tables)

Note 5 - Borrowings (Tables)	6 Months Ended
	Jun. 30, 2021
Notes Tables
Schedule of Debt [Table Text Block]	Year Ending December 31, 2021 (remaining six 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 June 30, 2021 (7,576 ) Less: Amount representing debt issuance costs (374 ) Borrowings, as of June 30, 2021 $ 11,434

Note 6 - Leases (Tables)

Note 6 - Leases (Tables)	6 Months Ended
	Jun. 30, 2021
Notes Tables
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	Year Ending December 31, 2021 (remaining six months of the year) $ 563 2022 1,162 2023 1,203 2024 1,138 4,066 Less: Imputed interest (436 ) Leasehold liability as of June 30, 2021 $ 3,630

Note 8 - Stockholders' Equity (

Note 8 - Stockholders' Equity (Tables)	6 Months Ended
	Jun. 30, 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 (134 ) 2,546.69 Forfeited — — Balance at June 30, 2021 6,687 $ 1,215.43 5.40 $ — Exercisable at June 30, 2021 6,687 $ 1,215.43 5.40 $ — Vested and expected to vest at June 30, 2021 6,687 $ 1,215.43 5.40 $ —
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 (54,873 ) $ 2.51 Forfeited (27,432 ) $ 2.48 Awards outstanding at June 30, 2021 420,337 $ 3.63 0.78

Note 9 - Stock-based Compensa_2

Note 9 - Stock-based Compensation (Tables)	6 Months Ended
	Jun. 30, 2021
Notes Tables
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]	Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Cost of revenues $ 34 $ 27 $ 68 $ 61 Research and development expenses 84 106 195 238 Selling, general and administrative expenses 185 192 458 477 $ 303 $ 325 $ 721 $ 776

Note 1 - Organization (Details

Note 1 - Organization (Details Textual) - USD ($) $ / shares in Units, $ in Thousands

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

Jun. 30, 2021

Dec. 31, 2020

Retained Earnings (Accumulated Deficit), Ending Balance

$ (374,845)

$ (367,341)

Cash and Cash Equivalents, at Carrying Value, Ending Balance

$ 26,700

$ 22,185

Proceeds from Issuance or Sale of Equity, Net

$ 15,500

Share Price (in dollars per share)

$ 1.23

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

January 2020 Public Offering [Member]

Proceeds from Issuance or Sale of Equity, Net

$ 3,900

$ 3,900

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

June and July 2020 Public Offering [Member]

Proceeds from Issuance or Sale of Equity, Net

$ 5,500

August and September 2020 Public Offering [Member]

Proceeds from Issuance or Sale of Equity, Net

$ 11,300

February 2021 Public Offering [Member]

Proceeds from Issuance or Sale of Equity, Net

$ 13,100

$ 13,100

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

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

$ 5,500

$ 700

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

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

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		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021shares	Jun. 30, 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			1		1
Customer Concentration Risk [Member] | Accounts Receivable [Member] | One Customer [Member]
Concentration Risk, Percentage			16.00%		14.00%
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | UNITED STATES
Concentration Risk, Percentage	94.00%	93.00%	94.00%	96.00%

Note 2 - Summary of Significa_4

Note 2 - Summary of Significant Accounting Policies - Product Warranty (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Beginning balance	$ 211	$ 221	$ 193	$ 215
Warranty provision	21	50	41	111
Usage/Release	(1)	(50)	(3)	(105)
Ending balance	$ 231	$ 221	$ 231	$ 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		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net loss applicable to common stockholders	$ (3,496)	$ (4,967)	$ (9,592)	$ (11,785)
Weighted average common stock outstanding, basic and diluted (in shares)	95,352	27,310	93,404	20,963
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.04)	$ (0.18)	$ (0.10)	$ (0.56)

Note 2 - Summary of Significa_6

Note 2 - Summary of Significant Accounting Policies - Anti-dilutive Securities (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Antidilutive Securities (in shares)	3,235,772	3,649,439	3,234,868	3,666,451
Common Stock Warrants [Member]
Antidilutive Securities (in shares)	2,753,999	2,753,999	2,753,999	2,753,999
Common Stock Options [ member]
Antidilutive Securities (in shares)	6,739	7,133	6,755	7,200
Preferred Stock [Member]
Antidilutive Securities (in shares)	52,276	48,503	52,302	48,503
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities (in shares)	422,758	839,804	421,812	856,749

Note 3 - Fair Value Measureme_2

Note 3 - Fair Value Measurements (Details Textual) - USD ($) $ in Thousands	Jun. 30, 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	Jun. 30, 2021	Dec. 31, 2020
Raw materials	$ 1,974	$ 1,904
Work-in-process	423	180
Finished products	1,721	1,792
Total inventories	$ 4,118	$ 3,876

Note 5 - Borrowings (Details Te

Note 5 - Borrowings (Details Textual) - USD ($)	Jan. 22, 2021	Apr. 23, 2020	Feb. 14, 2018	Apr. 30, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Apr. 17, 2021	Dec. 31, 2020	Mar. 02, 2020	Jun. 15, 2016	Sep. 22, 2015
Gain (Loss) on Extinguishment of Debt, Total							$ 2,353,000	$ 0
Interest Expense, Total					$ 400,000	$ 414,000	798,000	812,000
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					1,000	4,000	7,000	4,000
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 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					374,000		374,000			$ 418,000			1,300,000
Amortization of Debt Discount (Premium)					16,000	42,000	44,000	84,000
Interest Expense, Debt, Total					$ 397,000	$ 410,000	$ 790,000	$ 808,000
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 ($)	Jun. 30, 2021	Dec. 31, 2020
Borrowings, as of June 30, 2021	$ 0	$ 3,590,000
Loan Agreement [Member] | CRG [Member]
2021 (remaining six months of the year)	0
2022	0
2023	0
2024	9,045,000
Long-Term Debt, Maturity, Year Four	10,339,000
Long-term Debt, Total	19,384,000
Less: Amount of PIK additions and final facility fee to be incurred subsequent to June 30, 2021	(7,576,000)
Less: Amount representing debt issuance costs	(374)
Borrowings, as of June 30, 2021	$ 11,434,000

Note 6 - Leases (Details Textua

Note 6 - Leases (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Apr. 01, 2019
Lessee, Operating Lease, Liability, Payments, Due, Total	$ 4,066,000		$ 4,066,000		$ 5,800,000
Operating Lease, Weighted Average Remaining Lease Term (Year)	3 years 4 months 24 days		3 years 4 months 24 days
Lessee, Operating Lease, Discount Rate	6.50%		6.50%
Operating Lease, Expense, Excluding Maintenance Fee and Other Expense, Monthly	$ 105,000
Operating Lease, Expense	314,000	$ 314,000	$ 628,000	$ 628,000
Operating Lease, Right-of-Use Asset, Amortization Expense	253,000	$ 239,000	502,000	$ 475,000
Prepaid Rent	$ 223,000		$ 223,000

Note 6 - Leases - Future Operat

Note 6 - Leases - Future Operating Lease Payments (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Apr. 01, 2019
2021 (remaining six months of the year)	$ 563
2022	1,162
2023	1,203
2024	1,138
Lessee, Operating Lease, Liability, to be Paid, Total	4,066	$ 5,800
Less: Imputed interest	(436)
Leasehold liability as of June 30, 2021	$ 3,630

Note 7 - Commitments and Cont_2

Note 7 - Commitments and Contingencies (Details Textual) $ in Millions	Jun. 30, 2021USD ($)
Purchase Commitment [Member]
Purchase Obligation, Total	$ 1.3

Note 8 - Stockholders' Equity_2

Note 8 - Stockholders' Equity (Details Textual) - USD ($)	Feb. 16, 2018	Feb. 14, 2018	Jul. 30, 2021	Dec. 31, 2020	Dec. 31, 2019	Jan. 31, 2019	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Mar. 10, 2020	Aug. 28, 2019	Aug. 22, 2018
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			52,276
Preferred Stock, Shares Outstanding, Ending Balance (in shares)				52,369			52,276			52,276
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			95,353,002			95,353,002
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 Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares)										0	0
Share-based Payment Arrangement, Expense							$ 303,000		$ 325,000	$ 721,000	$ 776,000
Share-based Payment Arrangement, Expense, Tax Benefit									0	$ 0	0
Share Price (in dollars per share)							$ 1.23			$ 1.23
Share-based Payment Arrangement, Option [Member]
Share-based Payment Arrangement, Expense							$ 0		10,000	$ 4,000	42,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total							0			0
Share-based Payment Arrangement, Expense, Tax Benefit							0
Restricted Stock Units (RSUs) [Member]
Share-based Payment Arrangement, Expense							300,000		300,000	700,000	700,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total							$ 500,000			$ 500,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)										9 months 18 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance (in shares)				412,642			420,337			420,337
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Fair Value							$ 500,000			$ 500,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value										$ 88,000	1,200
The 2015 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares)							162,496			162,496
Officer and Director Share Purchase Plan [Member]
Common Stock, Shares, Issued, Total (in shares)							0			0
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares)							92,170			92,170
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)												125,000	40,000	20,000
Series B Financing Warrants [Member] | Subsequent Event [Member]
Class Of Warrant Or Right Warrants Expired (in shares)			1,083,091
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)								372,000
Series A Preferred Stock [Member]
Preferred Stock, Shares Outstanding, Ending Balance (in shares)							52,191			52,191
Dividends, Preferred Stock, Total							$ 1,000,000		$ 967,000	$ 2,100,000	$ 1,900,000
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			85
Stock Issued During Period, Shares, New Issues (in shares)	17,979
Preferred Stock, Convertible, Conversion Price (in dollars per share)				$ 0.25			$ 0.25			$ 0.25
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	Jun. 30, 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
July 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
November 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 4 months 24 days	5 years 9 months 21 days
Expired (in shares)	(134)
Expired, weighted average exercise price (in dollars per share)	$ 2,546,690
Options (in shares)	6,687	6,821
Options, weighted average exercise price (in dollars per share)	$ 1,215.43	$ 1,241.59
Exercisable (in shares)	6,687
Exercisable, weighted average exercise price (in dollars per share)	$ 1,215.43
Exercisable, weighted average remaining contractual life (Year)	5 years 4 months 24 days
Vested and expected to vest (in shares)	6,687
Vested and expected to vest, weighted average exercise price (in dollars per share)	$ 1,215.43
Vested and expected to vest, weighted average remaining contractual life (Year)	5 years 4 months 24 days

Note 8 - Stockholders' Equity_3

Note 8 - Stockholders' Equity - Restricted Stock Units Award Activity (Details) - Restricted Stock Units (RSUs) [Member] - $ / shares	6 Months Ended	12 Months Ended
	Jun. 30, 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)	9 months 10 days	11 months 23 days
Awarded, Shares (in shares)	90,000
Awarded, Weighted grant date fair value (in dollars per share)	$ 1.61
Released, Shares (in shares)	(54,873)
Released, Weighted grant date fair value (in dollars per share)	$ 2.51
Forfeited, Shares (in shares)	(27,432)
Forfeited, Weighted grant date fair value (in dollars per share)	$ 2.48
Awards outstanding, Shares (in shares)	420,337	412,642
Awards outstanding, Weighted grant date fair value (in dollars per share)	$ 3.63	$ 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		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Allocated Share-based Compensation Expense	$ 303	$ 325	$ 721	$ 776
Cost of Sales [Member]
Allocated Share-based Compensation Expense	34	27	68	61
Research and Development Expense [Member]
Allocated Share-based Compensation Expense	84	106	195	238
Selling, General and Administrative Expenses [Member]
Allocated Share-based Compensation Expense	$ 185	$ 192	$ 458	$ 477