Note 2 - Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2023

Notes Tables

Schedule of Product Warranty Liability [Table Text Block]

	Year Ended December 31,
	2023			2022
Beginning balance	$	50		$	80
Add: Accruals for warranties issued during the period		—			42
Less: Adjustment for inventory at cost and excessive and obsolete inventory		(50	)		(72	)
Ending balance	$	—		$	50

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

	Year Ended December 31,
	2023		2022
Common stock warrants		—		7,303,832
Common stock options		9,466,036		5,250,696
Total		9,466,036		12,554,528