Note 8 - Revenue - Disaggregation of Revenue (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Net revenues	$ 2,273,000	$ 3,029,000	$ 4,845,000	$ 5,692,000
Device [Member] | AXP [Member]
Net revenues	1,316,000	1,963,000	2,855,000	3,730,000
Device [Member] | BioArchive [Member]
Net revenues	789,000	643,000	1,446,000	1,096,000
Device [Member] | CAR-TXpress [Member]
Net revenues	130,000	292,000	276,000	604,000
Device [Member] | Manual Disposables [Member]
Net revenues	14,000	102,000	221,000	207,000
Device [Member] | Other Subsegments [Member]
Net revenues	24,000	29,000	47,000	55,000
Device Revenue [Member]
Net revenues	1,781,000	2,549,000	3,822,000	4,735,000
Device Revenue [Member] | Device [Member] | AXP [Member]
Net revenues	1,275,000	1,923,000	2,759,000	3,634,000
Device Revenue [Member] | Device [Member] | BioArchive [Member]
Net revenues	450,000	338,000	748,000	493,000
Device Revenue [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	24,000	163,000	59,000	361,000
Device Revenue [Member] | Device [Member] | Manual Disposables [Member]
Net revenues	14,000	102,000	221,000	207,000
Device Revenue [Member] | Device [Member] | Other Subsegments [Member]
Net revenues	18,000	23,000	35,000	40,000
Service [Member]
Net revenues	415,000	403,000	869,000	800,000
Service [Member] | Device [Member] | AXP [Member]
Net revenues	41,000	40,000	96,000	96,000
Service [Member] | Device [Member] | BioArchive [Member]
Net revenues	339,000	305,000	698,000	603,000
Service [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	35,000	58,000	75,000	101,000
Service [Member] | Device [Member] | Manual Disposables [Member]
Net revenues	0	0	0	0
Service [Member] | Device [Member] | Other Subsegments [Member]
Net revenues	0	0	0	0
Other [Member]
Net revenues	77,000	77,000	154,000	157,000
Other [Member] | Device [Member] | AXP [Member]
Net revenues	0	0	0	0
Other [Member] | Device [Member] | BioArchive [Member]
Net revenues	0	0	0	0
Other [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	71,000	71,000	142,000	142,000
Other [Member] | Device [Member] | Manual Disposables [Member]
Net revenues	0	0	0	0
Other [Member] | Device [Member] | Other Subsegments [Member]
Net revenues	6,000	6,000	12,000	15,000
UNITED STATES
Net revenues	1,717,000	1,573,000	3,089,000	3,439,000
CHINA
Net revenues	28,000	1,117,000	48,000	1,206,000
All Other Countries [Member]
Net revenues	$ 528,000	$ 339,000	$ 1,708,000	$ 1,047,000