Note 8 - Revenue - Disaggregation of Revenue (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Net revenues	$ 2,737,000	$ 2,572,000
Net revenues	2,737,000	2,572,000
Device [Member] | AXP [Member]
Net revenues	1,964,000	1,539,000
Net revenues	1,964,000	1,539,000
Device [Member] | BioArchive [Member]
Net revenues	522,000	657,000
Net revenues	522,000	657,000
Device [Member] | CAR-TXpress [Member]
Net revenues	146,000	146,000
Net revenues	146,000	146,000
Device [Member] | Other Subsegments [Member]
Net revenues	105,000	230,000
Net revenues	105,000	230,000
Device Revenue [Member]
Net revenues	2,128,000	2,041,000
Net revenues	2,128,000	2,041,000
Device Revenue [Member] | Device [Member] | AXP [Member]
Net revenues	1,900,000	1,484,000
Net revenues	1,900,000	1,484,000
Device Revenue [Member] | Device [Member] | BioArchive [Member]
Net revenues	188,000	298,000
Net revenues	188,000	298,000
Device Revenue [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	20,000	35,000
Net revenues	20,000	35,000
Device Revenue [Member] | Device [Member] | Other Subsegments [Member]
Net revenues	20,000	224,000
Net revenues	20,000	224,000
Service [Member]
Net revenues	424,000	454,000
Net revenues	424,000	454,000
Service [Member] | Device [Member] | AXP [Member]
Net revenues	64,000	55,000
Net revenues	64,000	55,000
Service [Member] | Device [Member] | BioArchive [Member]
Net revenues	334,000	359,000
Net revenues	334,000	359,000
Service [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	26,000	40,000
Net revenues	26,000	40,000
Service [Member] | Device [Member] | Other Subsegments [Member]
Net revenues	0	0
Net revenues	0	0
Other [Member]
Net revenues	185,000	77,000
Net revenues	185,000	77,000
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	100,000	71,000
Net revenues	100,000	71,000
Other [Member] | Device [Member] | Other Subsegments [Member]
Net revenues	85,000	6,000
Net revenues	85,000	6,000
UNITED STATES
Net revenues	2,064,000	1,372,000
Net revenues	2,064,000	1,372,000
SINGAPORE
Net revenues	56,000	404,000
Net revenues	56,000	404,000
All Other Countries [Member]
Net revenues	617,000	796,000
Net revenues	$ 617,000	$ 796,000