Note 9 - Financing Activities (Details Textual)								1 Months Ended			3 Months Ended			9 Months Ended
		Jul. 29, 2024 USD ($) shares	Jul. 26, 2024 $ / shares shares	May 30, 2024 $ / shares shares	Mar. 24, 2024 USD ($) shares	May 01, 2023 USD ($) $ / shares shares	Apr. 27, 2023	Jun. 30, 2024 USD ($) shares	Dec. 31, 2023 USD ($) $ / shares shares	May 31, 2023 USD ($) $ / shares	Sep. 30, 2024 USD ($) $ / shares shares		Sep. 30, 2023 USD ($) $ / shares	Sep. 30, 2024 USD ($) $ / shares shares		Sep. 30, 2023 USD ($) $ / shares shares	Sep. 27, 2024 $ / shares	Mar. 31, 2024 $ / shares shares	Dec. 31, 2022 $ / shares
Class of Warrant or Right, Issued During Period (in shares)														10,730,589		145,056
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares									$ 50.96		$ 1.41		$ 76.23	$ 1.41		$ 76.23			$ 269.54
Class of Warrant or Right, Exercised During Period (in shares)														90,381		(0)
Modification of Warrants | $														$ 69,000		$ 285,000
Fair Value Adjustment of Warrants | $											$ (0)		$ (0)	(114,000)		$ (216,000)
The 2024 Warrant Reprice Transaction [Member]
Debt Issuance Costs, Net | $											$ 96,000			$ 96,000
Unsecured Convertible Notes [Member]
Debt Issuance Costs, Net | $					$ 130,000
Debt Instrument, Face Amount | $					$ 525,000
Debt Instrument, Convertible, Number of Equity Instruments				107,146	3,750,000
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs | $					$ 19,000
Other Expenses | $					$ 111,000
Original Issue Discount Senior Secured Convertible Debentures [Member]
Debt Issuance Costs, Net | $						$ 300,000
Debt Instrument, Face Amount | $						3,300,000
Debt Instrument, Convertible, Number of Equity Instruments				72,528			2,538,464
Fair Value Adjustment of Warrants | $						40,000
Debt Instrument, Unamortized Discount | $						$ 300,000
Prefunded Warrants 2024 Public Offering [Member]
Class of Warrant or Right, Issued During Period (in shares)			2,041,814											2,041,814
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			$ 0.01														$ 0.66
Stock Issued In Connection with Exercise of Warrants, Shares (in shares)											2,041,814			2,041,814
Class of Warrant or Right, Exercised During Period (in shares)														2,041,814
Series F-1 Warrants [Member]
Class of Warrant or Right, Issued During Period (in shares)			3,200,380
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			3,200,380
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			$ 1.1								$ 0.66	[1]		$ 0.66	[1]
Warrants and Rights Outstanding, Term (Year)			5 years
Series F-2 Warrants [Member]
Class of Warrant or Right, Issued During Period (in shares)			3,200,380
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			3,200,380
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			$ 1.1								$ 0.66	[1]		$ 0.66	[1]
Warrants and Rights Outstanding, Term (Year)											6 months			6 months
Series F-3 Warrants [Member]
Class of Warrant or Right, Issued During Period (in shares)			3,200,380
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			3,200,380
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			$ 1.1								$ 0.66	[1]		$ 0.66	[1]
Warrants and Rights Outstanding, Term (Year)			1 year
Existing Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares											$ 2.5			$ 2.5
Class of Warrant or Right, Exercised During Period (in shares)								90,381
Proceeds from Warrant Exercises | $								$ 200,000
June 2024 Warrant [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)											90,381			90,381
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares	[1]										$ 2.57			$ 2.57
Warrants and Rights Outstanding, Term (Year)											5 years 6 months			5 years 6 months
The 2024 Warrant Reprice Transaction [Member]
Modification of Warrants | $											$ (69)			$ (69)
March 2024 Warrant [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				28,572	1,000,000													1,000,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares				$ 4.9							$ 4.9	[1]		$ 4.9	[1]			$ 0.14
May 2023 Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)									2,528,848
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares				$ 8.75						$ 1.3	8.75			8.75
Proceeds from Warrant Exercises | $									$ 200,000
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs | $									100,000
Fair Value Adjustment of Warrants | $								$ (47,000)	$ (170,000)
May 2023 Warrants [Member] | Post-split Amount [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares										$ 45.5
The 2023 Warrant Reprice Transaction [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				72,256					2,528,848
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares									$ 0.25
Proceeds from Warrant Exercises | $									$ 600,000
Debt Issuance Costs, Net | $									200,000
Other Expenses | $									$ 100,000
The 2023 Warrant Reprice Transaction [Member] | Post-split Amount [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares									$ 8.75
The December 2023 Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				72,256					2,528,848
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares				$ 8.75					$ 0.25		$ 8.75	[1]		$ 8.75	[1]
Proceeds from Warrant Exercises | $									$ 400,000
The 2023 Private Placement [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				145,056		5,076,928
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares						$ 1.5
Fair Value Adjustment of Warrants | $						$ 400,000
The 2024 Public Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)			1,158,566
Maximum Percentage of Common Stock Outstanding			4.99%
Proceeds from Issuance of Stock and Warrants | $		$ 3,900,000
The 2024 Public Offering [Member] | Election of the holder prior to the date of issuance [Member]
Maximum Percentage of Common Stock Outstanding			9.99%
Over-Allotment Option [Member] | Underwriter From 2024 Public Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)		336,832
Over-Allotment Option [Member] | Maximum Amount Purchasable By Underwriter [Member] | Underwriter From 2024 Public Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)			477,272
Over-Allotment Option [Member] | Series F-1 Warrants [Member] | Underwriter From 2024 Public Offering [Member]
Class of Warrant or Right, Issued During Period (in shares)		336,832
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		336,832
Over-Allotment Option [Member] | Series F-1 Warrants [Member] | Maximum Amount Purchasable By Underwriter [Member] | Underwriter From 2024 Public Offering [Member]
Class of Warrant or Right, Issued During Period (in shares)			477,272
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			477,272
Over-Allotment Option [Member] | Series F-2 Warrants [Member] | Underwriter From 2024 Public Offering [Member]
Class of Warrant or Right, Issued During Period (in shares)		336,832
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		336,832
Over-Allotment Option [Member] | Series F-2 Warrants [Member] | Maximum Amount Purchasable By Underwriter [Member] | Underwriter From 2024 Public Offering [Member]
Class of Warrant or Right, Issued During Period (in shares)			477,272
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			477,272
Over-Allotment Option [Member] | Series F-3 Warrants [Member] | Underwriter From 2024 Public Offering [Member]
Class of Warrant or Right, Issued During Period (in shares)		336,832
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		336,832
Over-Allotment Option [Member] | Series F-3 Warrants [Member] | Maximum Amount Purchasable By Underwriter [Member] | Underwriter From 2024 Public Offering [Member]
Class of Warrant or Right, Issued During Period (in shares)			477,272
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			477,272
The 2023 Private Placement [Member]
Debt Issuance Costs, Net | $						700,000
Other Expenses | $						400,000
Proceeds From Debenture and Warrant Issuances, Net | $						3,000,000
Proceeds from Issuance of Warrants | $						1,600,000
Proceeds from Derivative Instrument, Financing Activities | $										$ 200,000
Proceeds from Convertible Debt | $						1,200,000
The 2023 Private Placement [Member] | Original Issue Discount Senior Secured Convertible Debentures [Member]
Debt Instrument, Unamortized Discount | $						$ 300,000

[1] After giving retroactive effect to the 1-for-35 Reverse Stock Split that became effective May 30, 2024.