Note 16 - Income Taxes - Reconciliation of Federal Income Tax Attributable to Operations to Income Tax Expense (Benefit) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Statutory federal income tax benefit	$ (2,495,000)	$ (3,530,000)
Intangible assets		69,000
PPP loan forgiveness	(137,000)
Incentive stock options	257,000	56,000
Change in valuation allowance	(72,000)	197,000
Expiration of net operating losses	1,242,000	1,558,000
Disallowed financing costs	1,282,000	1,619,000
State and local taxes	(195,000)	(31,000)
Foreign rate differential	26,000	13,000
Other	$ 92,000	$ 49,000