Note 4 - Equipment and Leasehold Improvements - Property, Plant, and Equipment (Details) - USD ($)		Dec. 31, 2023	Dec. 31, 2022
Total equipment		$ 10,159,000	$ 8,429,000
Less accumulated depreciation		(7,575,000)	(7,175,000)
Total equipment and leasehold improvements, net		2,586,000	1,254,000
Machinery and Equipment [Member]
Total equipment	[1]	$ 7,705,000	6,610,000
Machinery and Equipment [Member] | Minimum [Member]
Useful life (Year)	[1]	2 years 6 months
Machinery and Equipment [Member] | Maximum [Member]
Useful life (Year)	[1]	10 years
Computer and Software [Member]
Total equipment		$ 631,000	631,000
Computer and Software [Member] | Minimum [Member]
Useful life (Year)		2 years
Computer and Software [Member] | Maximum [Member]
Useful life (Year)		5 years
Office Equipment [Member]
Total equipment		$ 270,000	256,000
Office Equipment [Member] | Minimum [Member]
Useful life (Year)		5 years
Office Equipment [Member] | Maximum [Member]
Useful life (Year)		10 years
Leasehold Improvements [Member]
Total equipment		$ 1,555,000	$ 932,000
Useful life (Year)		5 years

[1] Includes $131,000 and $391,000 for cost related to construction in progress for the years ended December 31, 2023 and 2022, respectively.