Note 14 - Stockholders Equity (Details Textual) | | | | | | | | | | 1 Months Ended | 12 Months Ended | 24 Months Ended | | | |
Oct. 20, 2023 USD ($) shares | Oct. 04, 2023 $ / shares shares | Sep. 08, 2023 USD ($) shares | Jul. 12, 2023 USD ($) shares | May 15, 2023 USD ($) shares | May 11, 2023 | May 11, 2023 | May 10, 2023 | Jul. 12, 2022 USD ($) $ / shares shares | Dec. 15, 2021 USD ($) $ / shares shares | Nov. 30, 2022 USD ($) $ / shares shares | Nov. 30, 2017 | Nov. 30, 2010 | Dec. 31, 2023 USD ($) $ / shares shares | Dec. 31, 2022 USD ($) $ / shares shares | Jun. 30, 2022 USD ($) $ / shares shares | May 31, 2023 USD ($) $ / shares | Dec. 31, 2021 shares | Jun. 16, 2020 USD ($) $ / shares shares |
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares | | | | | | | | | | | | | | $ 0.0001 | $ 0.0001 | | | | |
Proceeds from Issuance of Common Stock | | | | | | | | | | | | | | $ 816,000 | $ 2,135,000 | | | | |
Stock Issued During Period, Value, New Issues | | | | | | | | | | | | | | $ 816,000 | $ 2,204,000 | | | | |
Common Stock, Capital Shares Reserved for Future Issuance (in shares) | shares | | | | | | | | | | | | | | 18,887,958 | 6,378,417 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Payments | | | | | | | | | | | | | | $ 0 | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value | | | | | | | | | | | | | | $ 0 | $ 0 | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share) | $ / shares | | | | | | | | | | | | | | $ 2.81 | $ 9.3 | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested in Period, Fair Value | | | | | | | | | | | | | | $ 1,552,000 | $ 1,645,000 | | | | |
The 2010 Share Option Plan [Member] | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) | | | | | | | | | | | | 10 years | 7 years | | | | | | |
Common Stock, Capital Shares Reserved for Future Issuance (in shares) | shares | | | | | | | | | | | | | | 28,168 | 6,284 | | | | |
The 2019 Plan [Member] | | | | | | | | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares) | shares | | | | | | | | | | | | | | 30,000 | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares) | shares | | | | | | | | | | | | | | 71,412 | 18,715 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Increase in Authorized Shares, Percentage of Outstanding Stock Maximum | | | | | | | | | | | | | | 4% | | | | | |
Series A Preferred Stock [Member] | | | | | | | | | | | | | | | | | | | |
Preferred Stock, Shares Outstanding (in shares) | shares | | | | | | | | | | | | | | | | | | 252,717 | |
Voting Preferred Stock [Member] | | | | | | | | | | | | | | | | | | | |
Preferred Stock, Liquidation Preference Per Share (in dollars per share) | $ / shares | | | | | | | | | | | $ 30 | | | | | | | | |
Preferred Stock, Convertible, Conversion Ratio | | | | | | | | | | | 0.6667 | | | | | | | | |
Preferred Stock, Convertible, Volume Weighted Average Price Per Common Share (in dollars per share) | $ / shares | | | | | | | | | | | $ 18.75 | | | | | | | | |
Senior Preferred Stock [Member] | | | | | | | | | | | | | | | | | | | |
Preferred Stock, Convertible, Conversion Ratio | | | | | 2.6667 | | | | | | | | | | | | | | |
Liquidation Preference, Multiplier | | | | | 2.5 | | | | | | | | | | | | | | |
Conversion Price, Benchmark, Multiplier | | | | | 2.75 | | | | | | | | | | | | | | |
Series X Convertible Preferred Stock [Member][ | | | | | | | | | | | | | | | | | | | |
Shares Issued, Price Per Share (in dollars per share) | $ / shares | | $ 20.1 | | | | | | | | | | | | | | | | | |
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares | | $ 0.0001 | | | | | | | | | | | | | | | | | |
Preferred Stock, Convertible, Conversion Ratio | | 10 | | | | | | | | | | | | | | | | | |
Preferred Stock, Shares Authorized (in shares) | shares | | 400,000 | | | | | | | | | | | | | | | | | |
Preferred Stock, Dividend Rate, Percentage | | 12.50% | | | | | | | | | | | | | | | | | |
Common Stock [Member] | | | | | | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues (in shares) | shares | | | | | | | | | | | | | | 343,107 | 525,385 | | | | |
Stock Issued During Period, Value, New Issues | | | | | | | | | | | | | | $ 1,000 | $ 1,000 | | | | |
Equity Purchase Agreement [Member] | Lincoln Park [Member] | | | | | | | | | | | | | | | | | | | |
Equity Purchase Agreement, Maximum Offering Amount | | | | | | | | | | | | | | | | | | | $ 31,000,000 |
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares | | | | | | | | | | | | | | | | | | | $ 0.0001 |
Equity Purchase Agreement, Maximum Shares Issuable (in shares) | shares | | | | | | | | | | | | | | | | | | | 517,560 |
Equity Agreement, Maximum Percentage of Stock Outstanding | | | | | | | | | | | | | | | | | | | 19.99% |
Equity Agreement, Minimum Average Purchase Price (in dollars per share) | $ / shares | | | | | | | | | | | | | | | | | | | $ 59.6325 |
Maximum Percentage of Outstanding Stock, Beneficial Ownership | | | | | | | | | | | | | | | | | | | 9.99% |
Stock Issued During Period, Shares, New Issues (in shares) | shares | | | | | | | | | | | | | | | 26,666,000 | 229,139 | | | |
Shares Issued, Price Per Share (in dollars per share) | $ / shares | | | | | | | | | | | | | | | | $ 40.5 | | | |
Stock Issued During Period, Shares, Commitment Fee (in shares) | shares | | | | | | | | | | | | | | | | 13,971 | | | |
Stock Issued During Period, Value, Commitment Fee | | | | | | | | | | | | | | | | $ 620,000 | | | |
Deferred Offering Costs | | | | | | | | | | | | | | | $ 0 | $ 123,000 | | | |
Proceeds from Issuance of Common Stock | | | | | | | | | | | | | | | $ 272,000 | | | | |
LPC Purchase Agreement 2022 [Member] | Lincoln Park [Member] | | | | | | | | | | | | | | | | | | | |
Equity Purchase Agreement, Maximum Offering Amount | | | | | | | | | $ 11,000,000 | | | | | | | | | | |
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares | | | | | | | | | $ 0.0001 | | | | | | | | | | |
Equity Purchase Agreement, Maximum Shares Issuable (in shares) | shares | | | | | | | | | 858,224 | | | | | | | | | | |
Equity Agreement, Maximum Percentage of Stock Outstanding | | | | | | | | | 19.99% | | | | | | | | | | |
Maximum Percentage of Outstanding Stock, Beneficial Ownership | | | | | | | | | 9.99% | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues (in shares) | shares | | | | | | | | | | | | | | 343,116 | 433,336 | | | | |
Shares Issued, Price Per Share (in dollars per share) | $ / shares | | | | | | | | | | | | | | | $ 4.54 | | | | |
Stock Issued During Period, Shares, Commitment Fee (in shares) | shares | | | | | | | | | 45,701 | | | | | | | | | | |
Stock Issued During Period, Value, Commitment Fee | | | | | | | | | $ 330,000 | | | | | | | | | | |
Stock Issued During Period, Value, New Issues | | | | | | | | | | | | | | $ 1,109,000 | $ 1,970,000 | | | | |
The 2021 Private Placement [Member] | | | | | | | | | | | | | | | | | | | |
Proceeds from Issuance of Private Placement | | | | | | | | | | $ 17,000,000 | | | | | | | | | |
Payments of Stock Issuance Costs | | | | | | | | | | $ 300,000 | | | | | | | | | |
The 2021 Private Placement [Member] | Convertible Preferred Stock [Member] | | | | | | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues (in shares) | shares | | | | | | | | | | 252,717 | | | | | | | | | |
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares | | | | | | | | | | $ 0.0001 | | | | | | | | | |
The 2021 Private Placement [Member] | Common Stock [Member] | | | | | | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues (in shares) | shares | | | | | | | | | | 653,894 | | | | | | | | | |
The 2022 Private Placement [Member] | | | | | | | | | | | | | | | | | | | |
Proceeds from Issuance of Private Placement | | | | | | | | | | | $ 6,720,000 | | | $ 0 | 6,518,000 | | | | |
Payments of Stock Issuance Costs | | | | | | | | | | | $ 202,000 | | | | $ 202,000 | | | | |
The 2022 Private Placement [Member] | Convertible Preferred Stock [Member] | | | | | | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues (in shares) | shares | | | | | | | | | | | 3,185,000 | | | | | | | | |
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares | | | | | | | | | | | $ 0.0001 | | | | | | | | |
Preferred Stock, Convertible, Shares Issuable (in shares) | shares | | | | | | | | | | | 2,123,443 | | | | | | | | |
The 2022 Private Placement [Member] | Common Stock [Member] | | | | | | | | | | | | | | | | | | | |
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares | | | | | | | | | | | $ 0.0001 | | | | | | | | |
Stock Issued During Period, Shares, New Issues (in shares) | shares | | | | | | | | | | | 116,668 | | | | | | | | |
Multi-Tranche Private Placement 2023 [Member] | | | | | | | | | | | | | | | | | | | |
Equity Purchase Agreement, Maximum Offering Amount | | | | | | | | | | | | | | | | | $ 9,000,000 | | |
Equity Purchase Agreement, Minimum Aggregate Purchase Amount Per Tranche | | | | | | | | | | | | | | | | | $ 500,000 | | |
Multi-Tranche Private Placement 2023 [Member] | Senior Preferred Stock [Member] | | | | | | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues (in shares) | shares | 502,513 | | 292,398 | 500,000 | 280,899 | | | | | | | | | | | | | | |
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares | | | | | | | | | | | | | | | | | $ 0.0001 | | |
Proceeds from Issuance of Preferred Stock and Preference Stock | $ 2,000,000 | | $ 1,000,000 | $ 2,000,000 | $ 2,000,000 | | | | | | | | | | | | | | |
Weighted Average [Member] | LPC Purchase Agreement 2022 [Member] | Lincoln Park [Member] | | | | | | | | | | | | | | | | | | | |
Shares Issued, Price Per Share (in dollars per share) | $ / shares | | | | | | | | | | | | | | $ 3.23 | | | | | |
Reverse Stock Split [Member] | | | | | | | | | | | | | | | | | | | |
Stockholders' Equity Note, Stock Split, Conversion Ratio | | | | | | 15 | 15 | | | | | | | | | | | | |
Reverse Stock Split [Member] | Minimum [Member] | | | | | | | | | | | | | | | | | | | |
Stockholders' Equity Note, Stock Split, Conversion Ratio | | | | | | | | 5 | | | | | | | | | | | |
Reverse Stock Split [Member] | Maximum [Member] | | | | | | | | | | | | | | | | | | | |
Stockholders' Equity Note, Stock Split, Conversion Ratio | | | | | | | | 15 | | | | | | | | | | | |