Note 2 - Significant Accounting Policies 1 (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Retained Earnings (Accumulated Deficit), Total	$ (152,175,000)	$ (140,604,000)
Cash and Cash Equivalents, at Carrying Value, Total	1,103,000	7,363,000
Cash, Uninsured Amount	800,000
Accounts Receivable, Allowance for Credit Loss, Current	34,000	11,000
Revenue, Remaining Performance Obligation, Amount	$ 0	341,000
Standard Product Warranty, Term (Year)	2 years
Standard Product Warranty Accrual, Ending Balance	$ 0	$ 0