Note 6 - Stockholders' Equity (Details Textual) $ / shares in Units, $ in Thousands									12 Months Ended
		Sep. 07, 2023 USD ($) $ / shares shares	Apr. 03, 2023 USD ($) $ / shares shares	Jan. 04, 2023 USD ($) $ / shares shares	Nov. 15, 2022 shares	Aug. 16, 2022 USD ($) $ / shares shares	Aug. 12, 2022 USD ($) Days $ / shares shares	May 06, 2022 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 30, 2022 $ / shares shares
Common Stock, Shares Authorized (in shares)									280,000,000	280,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares									$ 0.01	$ 0.01
Common stock warrants									205,201
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares									$ 0.84
Common stock, shares issued (in shares)									9,270,894	2,944,306
Proceeds from issuance of common stock and warrants | $									$ 9,419	$ 14,401
Payment of cash equity issuance costs | $									$ 617	$ 627
Common Stock [Member]
Offering shares (Per share)					50
Reverse stock split fractional share settlement	[1]									(91)
Common Stock [Member] | Maximum [Member]
Reverse stock split fractional share settlement									1,541,508
Common Stock [Member] | Minimum [Member]
Reverse stock split fractional share settlement									77,080,169
Private Placement [Member]
Warrants to purchase shares of Company's common stock			2,272,723	1,052,631
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares			$ 2.64	$ 2.375
Date of issuance of warrant			5 years	5 years
Private Placement [Member] | Pre Funded Warrants [Member]
Warrants to purchase shares of Company's common stock			1,061,164	538,789
Common stock warrants			2.6399	2.3749
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares			$ 0.0001	$ 0.0001
Private Placement [Member] | Unregistered Shares [Member]
Offering shares (Per share)			455,242
Shares Issued, Price Per Share (in dollars per share) | $ / shares			$ 2.64
April 2023 Registered Direct Offering And Private Placement
Offering shares (Per share)			756,317
Shares Issued, Price Per Share (in dollars per share) | $ / shares			$ 2.64
Proceeds from issuance of common stock and warrants | $			$ 6,000
Payment of cash equity issuance costs | $			700
Net Proceeds from the exercise of warrants | $			5,300
Grant date fair value | $			$ 200
April 2023 Placement Agent Warrants
Warrants to purchase shares of Company's common stock			136,363
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares			$ 3.3
Date of issuance of warrant			5 years
January 2023 Registered Direct Offering and Private Placement
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares				$ 0.01
Offering shares (Per share)				476,842
Shares Issued, Price Per Share (in dollars per share) | $ / shares				$ 2.375
Proceeds from issuance of common stock and warrants | $				$ 2,500
Payment of cash equity issuance costs | $				300
Net Proceeds from the exercise of warrants | $				2,200
Grant date fair value | $				$ 200
January 2023 Registered Direct Offering and Private Placement | Pre Funded Warrants [Member]
Offering shares (Per share)				37,000
Common stock warrants				2.3749
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares				$ 0.0001
January 2023 Placement Agent Warrants
Warrants to purchase shares of Company's common stock											63,158
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares											$ 2.9688
Date of issuance of warrant											5 years
August 2022 Public Offering
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares						$ 0.01
Offering shares (Per share)						987,200
Consecutive trading day period | Days							30
Trading day conversion price period							300.00%
Proceeds from issuance of common stock and warrants | $						$ 13,800
Payment of cash equity issuance costs | $						2,300
Net Proceeds from the exercise of warrants | $						$ 11,500
August 2022 Public Offering | Warrant One [Member]
Warrants to purchase shares of Company's common stock						1,104,000
Date of issuance of warrant						1 year
August 2022 Public Offering | Warrant Two [Member]
Warrants to purchase shares of Company's common stock						1,104,000
Date of issuance of warrant						5 years
May 2022 Registered Direct Offering
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares								$ 0.01
Offering shares (Per share)								72,935
Aggregate Consideration | $								$ 2,000
Proceeds from issuance of common stock and warrants | $								1,400
Payment of cash equity issuance costs | $								$ 600
May 2022 Purchase Warrants [Member]
Warrants to purchase shares of Company's common stock								72,935
May2022 Placement Agent Warrants [Member]
Warrants to purchase shares of Company's common stock								4,376
Series B Convertible Preferred Stock [Member] | August 2022 Public Offering
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares							$ 0.01
Convertible Preferred Stock, Issuable Upon Conversion of All Shares (in shares)						80
Weighted average daily dollar trading volume | $							$ 500,000
Convertible Preferred Stock issued and outstanding						1,460	1,460
Series A 4.5% Convertible Preferred Stock [Member]
Preferred Stock, Shares Authorized (in shares)									1,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares									$ 0.01
Convertible Preferred Stock, Issuable Upon Conversion of All Shares (in shares)									129
Series A Preferred Stock [Member]
Preferred Stock, Shares Authorized (in shares)									7,000,000	7,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares									$ 0.01	$ 0.01
Common stock, shares issued (in shares)									200,000
Convertible Preferred Stock issued and outstanding									200,000
September 2023 Offering [Member]
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares		$ 0.01
Offering shares (Per share)		2,339,398
Shares Issued, Price Per Share (in dollars per share) | $ / shares		$ 0.84
Proceeds from issuance of common stock and warrants | $		$ 2,000
Payment of cash equity issuance costs | $		300
Net Proceeds from the exercise of warrants | $		1,700
Grant date fair value | $		$ 100

[1] (*) Adjusted to reflect the 1-for-50 reverse stock split effected on November 16, 2022.