Note 2 - Summary of Significant Accounting Policies - Revenues (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Net revenues	$ 9,744,000	$ 13,047,000
Device [Member] | AXP [Member]
Net revenues	4,934,000	7,522,000
Device [Member] | BioArchive [Member]
Net revenues	2,032,000	2,910,000
Device [Member] | Manual Disposables [Member]
Net revenues	599,000	977,000
Device [Member] | CAR-TXpress [Member]
Net revenues	1,828,000	1,565,000
Device [Member] | Other Subsegments [Member]
Net revenues	351,000	73,000
Device Revenue [Member]
Net revenues	7,988,000	11,219,000
Device Revenue [Member] | Device [Member] | AXP [Member]
Net revenues	4,774,000	7,313,000
Device Revenue [Member] | Device [Member] | BioArchive [Member]
Net revenues	855,000	1,472,000
Device Revenue [Member] | Device [Member] | Manual Disposables [Member]
Net revenues	599,000	977,000
Device Revenue [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	1,471,000	1,457,000
Device Revenue [Member] | Device [Member] | Other Subsegments [Member]
Net revenues	289,000
Service [Member]
Net revenues	1,408,000	1,682,000
Service [Member] | Device [Member] | AXP [Member]
Net revenues	160,000	209,000
Service [Member] | Device [Member] | BioArchive [Member]
Net revenues	1,177,000	1,438,000
Service [Member] | Device [Member] | Manual Disposables [Member]
Net revenues
Service [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	71,000	13,000
Service [Member] | Device [Member] | Other Subsegments [Member]
Net revenues		22,000
Other [Member]
Net revenues	348,000	146,000
Other [Member] | Device [Member] | AXP [Member]
Net revenues
Other [Member] | Device [Member] | BioArchive [Member]
Net revenues
Other [Member] | Device [Member] | Manual Disposables [Member]
Net revenues
Other [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	286,000	95,000
Other [Member] | Device [Member] | Other Subsegments [Member]
Net revenues	$ 62,000	$ 51,000