Note 8 - Revenue - Revenues (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Net revenues	$ 3,029,000	$ 2,201,000	$ 5,692,000	$ 3,718,000
Device [Member] | AXP [Member]
Net revenues	1,963,000	1,096,000	3,730,000	1,360,000
Device [Member] | BioArchive [Member]
Net revenues	643,000	549,000	1,096,000	1,299,000
Device [Member] | CAR-TXpress [Member]
Net revenues	292,000	389,000	604,000	743,000
Device [Member] | Manual Disposables [Member]
Net revenues	102,000	116,000	207,000	245,000
Device [Member] | Other Subsegments [Member]
Net revenues	29,000	51,000	55,000	71,000
Device Revenue [Member]
Net revenues	2,549,000	1,704,000	4,735,000	2,528,000
Device Revenue [Member] | Device [Member] | AXP [Member]
Net revenues	1,923,000	1,048,000	3,634,000	1,273,000
Device Revenue [Member] | Device [Member] | BioArchive [Member]
Net revenues	338,000	223,000	493,000	431,000
Device Revenue [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	163,000	287,000	361,000	542,000
Device Revenue [Member] | Device [Member] | Manual Disposables [Member]
Net revenues	102,000	116,000	207,000	245,000
Device Revenue [Member] | Device [Member] | Other Subsegments [Member]
Net revenues	23,000	30,000	40,000	37,000
Service [Member]
Net revenues	403,000	404,000	800,000	1,013,000
Service [Member] | Device [Member] | AXP [Member]
Net revenues	40,000	48,000	96,000	87,000
Service [Member] | Device [Member] | BioArchive [Member]
Net revenues	305,000	326,000	603,000	868,000
Service [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	58,000	30,000	101,000	58,000
Other [Member]
Net revenues	77,000	93,000	157,000	177,000
Other [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	71,000	72,000	142,000	143,000
Other [Member] | Device [Member] | Other Subsegments [Member]
Net revenues	6,000	21,000	15,000	34,000
UNITED STATES
Net revenues	1,573,000	1,016,000	3,439,000	2,041,000
CHINA
Net revenues	1,117,000	46,000	1,206,000	88,000
THAILAND
Net revenues		398,000	7,000	400,000
All Other Countries [Member]
Net revenues	$ 339,000	$ 741,000	$ 1,040,000	$ 1,189,000