Note 2 - Summary of Significant Accounting Policies - Revenues (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Net revenues	$ 2,962,000	$ 1,867,000
Device [Member]
Net revenues	2,951,000	1,805,000
Device [Member] | AXP [Member]
Net revenues	1,322,000	750,000
Device [Member] | BioArchive [Member]
Net revenues	1,014,000	767,000
Device [Member] | CAR-TXpress [Member]
Net revenues	307,000	18,000
Device [Member] | Manual Disposables [Member]
Net revenues	294,000	233,000
Device [Member] | Other Subsegments [Member]
Net revenues	14,000	37,000
Clinical Development [Member]
Net revenues	11,000	62,000
Clinical Development [Member] | Manual Disposables [Member]
Net revenues	6,000	22,000
Clinical Development [Member] | Other Subsegments [Member]
Net revenues	5,000	17,000
Clinical Development [Member] | Bone Marrow [Member]
Net revenues		23,000
Device Revenue [Member]
Net revenues	2,478,000	1,401,000
Device Revenue [Member] | Device [Member]
Net revenues	2,467,000	1,379,000
Device Revenue [Member] | Device [Member] | AXP [Member]
Net revenues	1,267,000	685,000
Device Revenue [Member] | Device [Member] | BioArchive [Member]
Net revenues	599,000	423,000
Device Revenue [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues	307,000	18,000
Device Revenue [Member] | Device [Member] | Manual Disposables [Member]
Net revenues	294,000	233,000
Device Revenue [Member] | Device [Member] | Other Subsegments [Member]
Net revenues		20,000
Device Revenue [Member] | Clinical Development [Member]
Net revenues	11,000	22,000
Device Revenue [Member] | Clinical Development [Member] | Manual Disposables [Member]
Net revenues	6,000	22,000
Device Revenue [Member] | Clinical Development [Member] | Other Subsegments [Member]
Net revenues	5,000
Device Revenue [Member] | Clinical Development [Member] | Bone Marrow [Member]
Net revenues
Service [Member]
Net revenues	470,000	449,000
Service [Member] | Device [Member]
Net revenues	470,000	409,000
Service [Member] | Device [Member] | AXP [Member]
Net revenues	55,000	65,000
Service [Member] | Device [Member] | BioArchive [Member]
Net revenues	415,000	344,000
Service [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues
Service [Member] | Device [Member] | Manual Disposables [Member]
Net revenues
Service [Member] | Device [Member] | Other Subsegments [Member]
Net revenues
Service [Member] | Clinical Development [Member]
Net revenues		40,000
Service [Member] | Clinical Development [Member] | Manual Disposables [Member]
Net revenues
Service [Member] | Clinical Development [Member] | Other Subsegments [Member]
Net revenues		17,000
Service [Member] | Clinical Development [Member] | Bone Marrow [Member]
Net revenues		23,000
Other [Member]
Net revenues	14,000	17,000
Other [Member] | Device [Member]
Net revenues	14,000	17,000
Other [Member] | Device [Member] | AXP [Member]
Net revenues
Other [Member] | Device [Member] | BioArchive [Member]
Net revenues
Other [Member] | Device [Member] | CAR-TXpress [Member]
Net revenues
Other [Member] | Device [Member] | Manual Disposables [Member]
Net revenues
Other [Member] | Device [Member] | Other Subsegments [Member]
Net revenues	14,000	17,000
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