Note 15 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2022

Notes Tables

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

	Year Ended December 31,
	2022			2021
Statutory federal income tax benefit	$	(2,481,000	)	$	(2,495,000	)
Intangible assets		-			-
PPP loan forgiveness					(137,000	)
Incentive stock options		-			257,000
Change in valuation allowance		(284,000	)		(72,000	)
Expiration of net operating losses		1,356,000			1,242,000
Disallowed financing costs		1,179,000			1,282,000
State and local taxes		200,000			(195,000	)
Foreign rate differential		11,000			26,000
Other		19,000			92,000
Total income tax expense	$	-		$	-

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

	Year Ended December 31,
	2022			2021
Deferred tax assets:
Net operating loss carryforwards	$	26,465,000		$	27,088,000
Income tax credit carryforwards		2,738,000			2,797,000
Stock compensation		421,000			437,000
Lease obligation		908,000			127,000
Deferred revenue		251,000			313,000
Inventory Reserve		517,000			449,000
Sec. 174 Capitalized R&D		317,000			-
Other		159,000			213,000
Total deferred tax assets		31,776,000			31,424,000
Deferred tax liabilities
Depreciation and amortization		(252,000	)		(320,000	)
Lease asset		(824,000	)		(120,000	)
Total deferred tax liabilities		(1,076,000	)		(440,000	)
Valuation allowance		(30,700,000	)		(30,984,000	)
Net deferred taxes	$	-		$	-