CONDENSED CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Trade accounts receivable, less allowances	$ 9	$ 20
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, authorized (in shares)	5,000,000	5,000,000
Preferred stock, issued (in shares)	876,447	876,447
Preferred stock, outstanding (in shares)	876,447	876,447
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, authorized (in shares)	50,000,000	50,000,000
Common stock, issued (in shares)	4,726,149	4,348,690
Common stock, outstanding (in shares)	4,726,149	4,348,690
Series A Convertible Preferred Stock
Preferred stock, authorized (in shares)	3,300,000	3,300,000