Note 8 - Revenue - Disaggregation of Revenue (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Net revenues	$ 2,194,000	$ 2,115,000	$ 7,039,000	$ 7,807,000
Device [Member] | AXP [Member]
Net revenues	1,574,000	1,109,000	4,429,000	4,839,000
Device [Member] | BioArchive [Member]
Net revenues	453,000	522,000	1,899,000	1,618,000
Device [Member] | CAR-TXpress [Member]
Net revenues	147,000	306,000	423,000	911,000
Device [Member] | Manual Disposables [Member]
Net revenues	8,000	150,000	229,000	357,000
Device [Member] | Other Subsegments [Member]
Net revenues	12,000	28,000	59,000	82,000
Device Revenue [Member]
Net revenues	1,673,000	1,595,000	5,495,000	6,329,000
Device Revenue [Member] | Device [Member] | AXP [Member]
Net revenues	1,486,000	1,034,000	4,245,000	4,668,000
Device Revenue [Member] | Device [Member] | BioArchive [Member]
Net revenues	131,000	201,000	879,000	694,000
Device Revenue [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	42,000	190,000	101,000	551,000
Device Revenue [Member] | Device [Member] | Manual Disposables [Member]
Net revenues	8,000	150,000	229,000	357,000
Device Revenue [Member] | Device [Member] | Other Subsegments [Member]
Net revenues	6,000	20,000	41,000	59,000
Service [Member]
Net revenues	444,000	440,000	1,313,000	1,241,000
Service [Member] | Device [Member] | AXP [Member]
Net revenues	88,000	75,000	184,000	171,000
Service [Member] | Device [Member] | BioArchive [Member]
Net revenues	322,000	321,000	1,020,000	924,000
Service [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	34,000	44,000	109,000	146,000
Other [Member]
Net revenues	77,000	80,000	231,000	237,000
Other [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	71,000	72,000	213,000	214,000
Other [Member] | Device [Member] | Other Subsegments [Member]
Net revenues	6,000	8,000	18,000	23,000
UNITED STATES
Net revenues	1,500,000	1,535,000	4,589,000	4,973,000
CHINA
Net revenues	29,000	364,000	77,000	1,570,000
UNITED ARAB EMIRATES
Net revenues	259,000		439,000
All Other Countries [Member]
Net revenues	$ 406,000	$ 216,000	$ 1,934,000	$ 1,264,000