v3.23.2

Note 12 - Warrants (Details Textual) |  |  |  |  |  | 1 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Dec. 29, 2022 USD ($) $ / shares shares | Dec. 27, 2022 $ / shares shares | Aug. 03, 2022 USD ($) $ / shares shares | Nov. 17, 2021 USD ($) $ / shares shares | Nov. 15, 2021 USD ($) $ / shares shares | Dec. 31, 2022 USD ($) $ / shares shares | Dec. 31, 2022 USD ($) $ / shares shares | Dec. 31, 2021 USD ($) $ / shares | Oct. 25, 2022 $ / shares | Dec. 31, 2020 shares | May 30, 2019 USD ($) $ / shares yr shares
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares |  |  |  |  |  | $ 0.001 | $ 0.001 | $ 0.001 | $ 0.001 |  |
Equity Issuance Costs, Modification of Warrants |  |  |  |  |  |  | $ 47,000 | $ 0 |  |  |
Warrants and Rights Outstanding |  |  |  |  |  | $ 7,098,000 | $ 7,098,000 | 0 |  |  |
Redeemable Convertible Preferred Stock [Member] |  |  |  |  |  |  |  |  |  |  |
Stock Issued During Period, Shares, New Issues (in shares) | shares |  |  | 3,000 |  |  |  |  |  |  |  |
Proceeds from Issuance or Sale of Equity, Net |  |  | $ 129,000 |  |  |  |  |  |  |  |
The 2022 Prefunded Warrants [Member] |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares |  | 2,632,898 |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares | $ 0.0001 |  |  |  |  |  |  |  |  |  |
Equity Offering, Price Per Unit (in dollars per share) | $ / shares | $ 2.22615 |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) | $ / shares | 2.22615 |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Outstanding (in shares) | shares |  |  |  |  |  | 2,632,898 | 2,632,898 |  |  |  |
Common Warrants [Member] |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares |  | 4,227,052 |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares | $ 2.07 |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Outstanding (in shares) | shares |  |  |  |  |  | 4,227,052 | 4,227,052 |  |  |  |
December 2022 Financing [Member] |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares | $ 2.07 |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding | $ 7,100,000 |  |  |  |  |  |  |  |  |  |
Proceeds from Issuance of Warrants | $ 335,000 |  |  |  |  |  |  |  |  |  |
December 2022 Financing [Member] | Measurement Input, Share Price [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) | $ / shares | 2.13 |  |  |  |  |  |  |  |  |  |
December 2022 Financing [Member] | Measurement Input, Expected Term [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) | 6 |  |  |  |  |  |  |  |  |  |
December 2022 Financing [Member] | Measurement Input, Price Volatility [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) | 0.9544 |  |  |  |  |  |  |  |  |  |
December 2022 Financing [Member] | Measurement Input, Risk Free Interest Rate [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) | 0.0393 |  |  |  |  |  |  |  |  |  |
December 2022 Financing [Member] | Measurement Input, Expected Dividend Rate [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) | 0 |  |  |  |  |  |  |  |  |  |
December 2022 Financing [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares | $ 1.00 |  |  |  |  |  |  |  |  |  |
August 2022 LPC Warrant [Member] |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares |  |  | 81,150 |  |  |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares | $ 2.07 |  | $ 4.07 |  |  | $ 2.07 | $ 2.07 |  |  |  |
Warrants and Rights Outstanding |  |  | $ 300,000 |  |  |  |  |  |  |  |
Proceeds from Issuance or Sale of Equity, Net |  |  | $ 110,000 |  |  |  |  |  |  |  |
August 2022 LPC Warrant [Member] | Measurement Input, Share Price [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) | $ / shares |  |  | 4.44 |  |  |  |  |  |  |  |
August 2022 LPC Warrant [Member] | Measurement Input, Expected Term [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) |  |  | 5.5 |  |  |  |  |  |  |  |
August 2022 LPC Warrant [Member] | Measurement Input, Price Volatility [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) |  |  | 0.8994 |  |  |  |  |  |  |  |
August 2022 LPC Warrant [Member] | Measurement Input, Risk Free Interest Rate [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) |  |  | 0.0286 |  |  |  |  |  |  |  |
August 2022 LPC Warrant [Member] | Measurement Input, Expected Dividend Rate [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) |  |  | 0 |  |  |  |  |  |  |  |
November 2021 Financing Warrants [Member] |  |  |  |  |  |  |  |  |  |  |
Stock Issued During Period, Shares, New Issues (in shares) | shares |  |  |  |  | 875,000 |  |  |  |  |  |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares |  |  |  |  | 875,000 | 125,000 | 125,000 |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares |  |  |  | $ 20.00 | $ 20.00 | $ 20.00 | $ 20.00 |  |  |  |
Warrants and Rights Outstanding |  |  |  | $ 5,600,000 | $ 8,600,000 |  |  |  |  |  |
Proceeds from Issuance of Warrants |  |  |  |  | $ 5,600,000 |  |  |  |  |  |
November 2021 Financing Warrants [Member] | Measurement Input, Share Price [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) |  |  |  |  | 14.92 |  |  |  |  |  |
November 2021 Financing Warrants [Member] | Measurement Input, Expected Term [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) |  |  |  |  | 5 |  |  |  |  |  |
November 2021 Financing Warrants [Member] | Measurement Input, Price Volatility [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) |  |  |  |  | 0.9177 |  |  |  |  |  |
November 2021 Financing Warrants [Member] | Measurement Input, Risk Free Interest Rate [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) |  |  |  |  | 0.0126 |  |  |  |  |  |
November 2021 Financing Warrants [Member] | Measurement Input, Expected Dividend Rate [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) |  |  |  |  | 0 |  |  |  |  |  |
November 2021 Financing Warrants [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Required Percentage of Ownership to Become Exercisable |  |  |  |  | 9.99% |  |  |  |  |  |
Modified November 2021 Warrants [Member] |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares | 750,000 |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares | $ 2.07 |  |  |  |  |  |  |  |  |  |
Equity Issuance Costs, Modification of Warrants | $ 800,000 |  |  |  |  |  |  |  |  |  |
Modified November 2021 Warrants [Member] | Additional Paid-in Capital [Member] |  |  |  |  |  |  |  |  |  |  |
Equity Issuance Costs, Modification of Warrants | 100,000 |  |  |  |  |  |  |  |  |  |
Modified November 2021 Warrants [Member] | Selling, General and Administrative Expenses [Member] |  |  |  |  |  |  |  |  |  |  |
Equity Issuance Costs, Modification of Warrants | $ 700,000 |  |  |  |  |  |  |  |  |  |
Modified November 2021 Warrants [Member] | Measurement Input, Share Price [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) | $ / shares | 2.13 |  |  |  |  |  |  |  |  |  |
Modified November 2021 Warrants [Member] | Measurement Input, Expected Term [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) | 6 |  |  |  |  |  |  |  |  |  |
Modified November 2021 Warrants [Member] | Measurement Input, Price Volatility [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) | 0.9544 |  |  |  |  |  |  |  |  |  |
Modified November 2021 Warrants [Member] | Measurement Input, Risk Free Interest Rate [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) | 0.0393 |  |  |  |  |  |  |  |  |  |
Modified November 2021 Warrants [Member] | Measurement Input, Expected Dividend Rate [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) | 0 |  |  |  |  |  |  |  |  |  |
Warrant In Connection with Oxford Finance Loan Agreement [Member] |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares |  |  |  |  |  |  |  |  |  |  | 8,833
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  |  | $ 56.60
Warrants and Rights Outstanding |  |  |  |  |  |  |  |  |  |  | $ 400,000
Class of Warrant or Right, Outstanding (in shares) | shares |  |  |  |  |  |  |  |  |  | 8,833 |
Warrants and Rights Outstanding, Term (Year) |  |  |  |  |  |  |  |  |  |  | 10 years
Warrant In Connection with Oxford Finance Loan Agreement [Member] | Measurement Input, Share Price [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  |  | 53.20
Warrant In Connection with Oxford Finance Loan Agreement [Member] | Measurement Input, Expected Term [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) | yr |  |  |  |  |  |  |  |  |  |  | 10
Warrant In Connection with Oxford Finance Loan Agreement [Member] | Measurement Input, Price Volatility [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) |  |  |  |  |  |  |  |  |  |  | 0.8022
Warrant In Connection with Oxford Finance Loan Agreement [Member] | Measurement Input, Risk Free Interest Rate [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) |  |  |  |  |  |  |  |  |  |  | 0.0222
Warrant In Connection with Oxford Finance Loan Agreement [Member] | Measurement Input, Expected Dividend Rate [Member] |  |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input (in dollars per share) |  |  |  |  |  |  |  |  |  |  | 0
Warrant In Connection with Oxford Finance Loan Agreement [Member] | Measurement Input, Exercise Price [Member] |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  |  | $ 56.60
December 2022 Financing [Member] |  |  |  |  |  |  |  |  |  |  |
Stock Issued During Period, Shares, New Issues (in shares) | shares |  | 748,744 |  |  |  |  |  |  |  |  |
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares |  | $ 0.001 |  |  |  |  |  |  |  |  |
Equity Offering, Price Per Unit (in dollars per share) | $ / shares | $ 2.22625 |  |  |  |  |  |  |  |  |  |
Proceeds from Issuance or Sale of Equity, Total |  |  |  |  |  | $ 7,500,000 |  |  |  |  |
Payments of Stock Issuance Costs |  |  |  |  |  | 1,700,000 |  |  |  |  |
Equity Issuance Costs, Modification of Warrants |  |  |  |  |  | $ 800,000 |  |  |  |  |
Proceeds from Issuance or Sale of Equity, After Warrant Adjustment | $ 400,000 |  |  |  |  |  |  |  |  |  |
Proceeds from Issuance of Common Stock | 95,000 |  |  |  |  |  |  |  |  |  |
Proceeds from Issuance or Sale of Equity, Net | $ 6,600,000 |  |  |  |  |  |  |  |  |  |
Securities Purchase Agreement [Member] |  |  |  |  |  |  |  |  |  |  |
Proceeds from Issuance or Sale of Equity, Total |  |  | $ 300,000 |  |  |  |  |  |  |  |
Proceeds from Issuance or Sale of Equity, Net |  |  | $ 200,000 |  |  |  |  |  |  |  |
2021 Registered Direct Offering [Member] |  |  |  |  |  |  |  |  |  |  |
Stock Issued During Period, Shares, New Issues (in shares) | shares |  |  |  | 875,000 |  |  |  |  |  |  |
Proceeds from Issuance or Sale of Equity, Total |  |  |  | $ 14,000,000.0 | $ 14,000,000.0 |  |  |  |  |  |
Proceeds from Issuance of Common Stock |  |  |  |  |  |  | $ 7,528,000 | 0 |  |  |
Proceeds from Issuance of Warrants |  |  |  |  |  |  | $ 0 | $ 13,918,000 |  |  |
2021 Registered Direct Offering [Member] | Measurement Input, Risk Free Interest Rate [Member] |  |  |  |  |  |  |  |  |  |  |
Proceeds from Issuance or Sale of Equity, Total |  |  |  |  | 14,000,000.0 |  |  |  |  |  |
Proceeds from Issuance of Common Stock |  |  |  |  | $ 8,400,000 |  |  |  |  |  |
2021 Registered Direct Offering [Member] | November 2021 Financing Warrants [Member] |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares |  |  |  | 875,000 |  |  |  |  |  |  |

X
- Definition Represents required percentage of ownership in order for warrants become exercisable. + References No definition available. + Details
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- Definition Represents the amount of modification of warrants for equity issuance costs. + References No definition available. + Details
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- Definition Represents the price per unit in an equity offering. + References No definition available. + Details
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- Definition Represents the amount of proceeds from issuance or sale of equity after warrant adjustments. + References No definition available. + Details
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- Definition Exercise price per share or per unit of warrants or rights outstanding. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481112/505-10-50-3 + Details
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- Definition Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481112/505-10-50-3 + Details
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- Definition Number of warrants or rights outstanding. + References No definition available. + Details
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- Definition Face amount or stated value per share of common stock. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 + Details
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