Note 12 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2022

Notes Tables

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	Years ended December 31,
	2022			2021
Tax at federal statutory rate	$	(2,500	)	$	(2,651	)
State, net of federal benefit		(190	)		—
Research and development credit		(291	)		(279	)
Share-based compensation		101			264
Other		—			2
Change in valuation allowance		2,880			2,664
Total provision for income taxes	$	—		$	—

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	Years ended December 31,
	2022			2021
Accrued compensation	$	189		$	191
Inventory adjustments		24			15
Depreciation and amortization		17			24
Share-based compensation		569			595
Net operating loss and tax credit carryforwards		31,499			30,277
Research and development capitalization		1,674			—
Other		12			2
Gross Deferred Tax Asset		33,984			31,104
Valuation Allowance		(33,984	)		(31,104	)
Net deferred tax asset	$	—		$	—

Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]

	Years ended December 31,
	2022		2021
Balance, beginning of year	$	1,368	$	1,235
Additions based on tax positions related to the current year		151		158
Reductions for tax positions related to prior years		—		(25	)
Balance, end of year	$	1,519	$	1,368