Note 2 - Summary of Significant Accounting Policies - Revenues (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Net revenues	$ 13,047,000	$ 9,672,000
Device [Member]
Net revenues	12,957,000	9,469,000
Device [Member] | AXP [Member]
Net revenues	7,522,000	4,393,000
Device [Member] | BioArchive [Member]
Net revenues	2,910,000	3,098,000
Device [Member] | Manual Disposables [Member]
Net revenues	909,000	976,000
Device [Member] | CAR-TXpress [Member]
Net revenues	1,565,000	907,000
Device [Member] | Other Subsegments [Member]
Net revenues	51,000	95,000
Clinical Development [Member]
Net revenues	90,000	203,000
Clinical Development [Member] | Manual Disposables [Member]
Net revenues	68,000
Clinical Development [Member] | Other Subsegments [Member]
Net revenues	22,000	68,000
Clinical Development [Member] | Bone Marrow [Member]
Net revenues		135,000
Device Revenue [Member]
Net revenues	11,219,000	7,844,000
Device Revenue [Member] | Device [Member]
Net revenues	11,151,000	7,806,000
Device Revenue [Member] | Device [Member] | AXP [Member]
Net revenues	7,313,000	4,131,000
Device Revenue [Member] | Device [Member] | BioArchive [Member]
Net revenues	1,472,000	1,792,000
Device Revenue [Member] | Device [Member] | Manual Disposables [Member]
Net revenues	909,000	976,000
Device Revenue [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	1,457,000	907,000
Device Revenue [Member] | Device [Member] | Other Subsegments [Member]
Net revenues
Device Revenue [Member] | Clinical Development [Member]
Net revenues	68,000	38,000
Device Revenue [Member] | Clinical Development [Member] | Manual Disposables [Member]
Net revenues	68,000
Device Revenue [Member] | Clinical Development [Member] | Other Subsegments [Member]
Net revenues		38,000
Device Revenue [Member] | Clinical Development [Member] | Bone Marrow [Member]
Net revenues
Service [Member]
Net revenues	1,682,000	1,733,000
Service [Member] | Device [Member]
Net revenues	1,660,000	1,568,000
Service [Member] | Device [Member] | AXP [Member]
Net revenues	209,000	262,000
Service [Member] | Device [Member] | BioArchive [Member]
Net revenues	1,438,000	1,306,000
Service [Member] | Device [Member] | Manual Disposables [Member]
Net revenues
Service [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	13,000
Service [Member] | Device [Member] | Other Subsegments [Member]
Net revenues
Service [Member] | Clinical Development [Member]
Net revenues	22,000	165,000
Service [Member] | Clinical Development [Member] | Manual Disposables [Member]
Net revenues
Service [Member] | Clinical Development [Member] | Other Subsegments [Member]
Net revenues	22,000	30,000
Service [Member] | Clinical Development [Member] | Bone Marrow [Member]
Net revenues		135,000
Other [Member]
Net revenues	146,000	95,000
Other [Member] | Device [Member]
Net revenues	146,000	95,000
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	95,000
Other [Member] | Device [Member] | Other Subsegments [Member]
Net revenues	51,000	95,000
Other [Member] | Clinical Development [Member]
Net revenues
Other [Member] | Clinical Development [Member] | Manual Disposables [Member]
Net revenues
Other [Member] | Clinical Development [Member] | Other Subsegments [Member]
Net revenues
Other [Member] | Clinical Development [Member] | Bone Marrow [Member]
Net revenues