Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands		Total	Cumulative Effect, Period of Adoption, Adjusted Balance	Preferred Stock	Common Stock		Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjusted Balance
Beginning balance (in shares) at Dec. 31, 2021				876,000
Beginning balance at Dec. 31, 2021		$ 6,209		$ 0	$ 0		$ 144,953	$ (3)	$ (138,741)
Beginning balance (in shares) at Dec. 31, 2021	[1]				910,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under employee stock option and stock purchase plans (in shares)	[1]				7,000
Issuance of common stock under employee stock option and stock purchase plans		6					6
Stock issued in exchange transactions (in shares)	[1]				94,000
Stock issued in exchange transactions		304					304
Issuance of common stock and warrants (in shares)	[1]				187,000
Issuance of common stock and warrants		3,500			$ 1		3,499
Offering costs on issuance of common stock and warrants		$ (334)					(334)
Issuance of common stock upon the exercise of warrants (in shares)		0			209,000	[1]
Stock-based compensation		$ 117					117
Net loss		(10,279)							(10,279)
Ending balance (in shares) at Dec. 31, 2022				876,000
Ending balance at Dec. 31, 2022		$ (477)		$ 0	$ 1		148,545	(3)	(149,020)
Ending balance (in shares) at Dec. 31, 2022		1,406,920			1,407,000	[1]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under employee stock option and stock purchase plans (in shares)	[1]				2,477,000
Issuance of common stock under employee stock option and stock purchase plans		$ 6,079			$ 1		6,078
Stock issued in exchange transactions (in shares)	[1]				465,000
Stock issued in exchange transactions		1,716					1,716
Par value adjustment due to reverse stock split		0			$ (2)		2
Reduction in equity due to costs from reverse stock split		$ (16)					(16)
Issuance of common stock upon the exercise of warrants (in shares)		0
Stock-based compensation		$ 44					44
Net loss		(4,293)							(4,293)
Ending balance (in shares) at Dec. 31, 2023				876,000
Ending balance at Dec. 31, 2023		$ 3,051	$ (2)	$ 0	$ 0		$ 156,369	$ (3)	$ (153,315)	$ (2)
Ending balance (in shares) at Dec. 31, 2023		4,348,690			4,349,000	[1]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]		Accounting Standards Update 2016-13 [Member]

[1] Shares outstanding for prior periods have been restated for the 1-for-7 reverse stock split effective June 16, 2023.