Note 3 - Income Taxes - Summary of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Stock compensation expense	$ 272	$ 173
Goodwill	182	591
Royalty accruals	10	10
Bad debt allowance	53	51
Net operating loss carryforwards	12,158	11,950
Credit carry-forwards	1,058	992
Inventory reserve	233	217
Depreciation	585	556
Research and Development Costs	528	0
Other	471	376
Total deferred tax assets	15,550	14,916
Deferred tax liabilities:
Intangible assets	(100)	(105)
Total deferred tax liabilities	(100)	(105)
Net deferred tax asset before valuation allowance	15,450	14,811
Valuation allowances for deferred tax assets	(15,627)	(14,950)	$ (15,971)
Net deferred tax liability	$ (177)	$ (139)