Note 8 - Revenue - Disaggregation of Revenue (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Net revenues	$ 2,572,000	$ 2,663,000
Net revenues	2,572,000	2,663,000
Device [Member] | AXP [Member]
Net revenues	1,539,000	1,766,000
Net revenues	1,539,000	1,766,000
Device [Member] | BioArchive [Member]
Net revenues	657,000	453,000
Net revenues	657,000	453,000
Device [Member] | CAR-TXpress [Member]
Net revenues	146,000	313,000
Net revenues	146,000	313,000
Device [Member] | Manual Disposables [Member]
Net revenues	207,000	105,000
Net revenues	207,000	105,000
Device [Member] | Other Subsegments [Member]
Net revenues	23,000	26,000
Net revenues	23,000	26,000
Device Revenue [Member]
Net revenues	2,041,000	2,187,000
Net revenues	2,041,000	2,187,000
Device Revenue [Member] | Device [Member] | AXP [Member]
Net revenues	1,484,000	1,711,000
Net revenues	1,484,000	1,711,000
Device Revenue [Member] | Device [Member] | BioArchive [Member]
Net revenues	298,000	155,000
Net revenues	298,000	155,000
Device Revenue [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	35,000	199,000
Net revenues	35,000	199,000
Device Revenue [Member] | Device [Member] | Manual Disposables [Member]
Net revenues	207,000	105,000
Net revenues	207,000	105,000
Device Revenue [Member] | Device [Member] | Other Subsegments [Member]
Net revenues	17,000	17,000
Net revenues	17,000	17,000
Service [Member]
Net revenues	454,000	396,000
Net revenues	454,000	396,000
Service [Member] | Device [Member] | AXP [Member]
Net revenues	55,000	55,000
Net revenues	55,000	55,000
Service [Member] | Device [Member] | BioArchive [Member]
Net revenues	359,000	298,000
Net revenues	359,000	298,000
Service [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	40,000	43,000
Net revenues	40,000	43,000
Service [Member] | Device [Member] | Manual Disposables [Member]
Net revenues	0	0
Net revenues	0	0
Service [Member] | Device [Member] | Other Subsegments [Member]
Net revenues	0	0
Net revenues	0	0
Other [Member]
Net revenues	77,000	80,000
Net revenues	77,000	80,000
Other [Member] | Device [Member] | AXP [Member]
Net revenues	0	0
Net revenues	0	0
Other [Member] | Device [Member] | BioArchive [Member]
Net revenues	0	0
Net revenues	0	0
Other [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	71,000	71,000
Net revenues	71,000	71,000
Other [Member] | Device [Member] | Manual Disposables [Member]
Net revenues	0	0
Net revenues	0	0
Other [Member] | Device [Member] | Other Subsegments [Member]
Net revenues	6,000	9,000
Net revenues	6,000	9,000
UNITED STATES
Net revenues	1,372,000	1,958,000
Net revenues	1,372,000	1,958,000
SINGAPORE
Net revenues	404,000	0
Net revenues	404,000	0
All Other Countries [Member]
Net revenues	796,000	705,000
Net revenues	$ 796,000	$ 705,000