Note 3 - Intangible Assets and Goodwill - Summary of Intangible Assets (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Gross Carrying Amount	$ 1,317,000	$ 1,355,000
Accumulated Amortization	993,000	891,000
Net	324,000	448,000
Impairment		16,000
Gross Carrying Amount	2,460,000	22,368,000
Impairment		19,886,000
Net	1,467,000	1,591,000	$ 21,629,000
In Process Techonology [Member]
Gross Carrying Amount	1,143,000	1,143,000
Impairment
Net	1,143,000	1,143,000
Clinical Protocols [Member]
Gross Carrying Amount		19,870,000
Impairment		19,870,000
Net
Trade Names [Member]
Weighted Average Amortization Period (Year)	3 years	3 years
Gross Carrying Amount	$ 53,000	$ 54,000
Accumulated Amortization	45,000	38,000
Net	$ 8,000	$ 16,000
Developed Technology Rights [Member]
Weighted Average Amortization Period (Year)	10 years	10 years
Gross Carrying Amount	$ 318,000	$ 318,000
Accumulated Amortization	79,000	48,000
Net	$ 239,000	$ 270,000
Licensing Agreements [Member]
Weighted Average Amortization Period (Year)	7 years	7 years
Gross Carrying Amount	$ 437,000	$ 448,000
Accumulated Amortization	367,000	307,000
Net	$ 70,000	$ 141,000
Device Registration [Member]
Weighted Average Amortization Period (Year)	7 years	7 years
Gross Carrying Amount	$ 66,000	$ 84,000
Accumulated Amortization	66,000	68,000
Net
Impairment		$ 16,000
Customer Relationships [Member]
Weighted Average Amortization Period (Year)	3 years	3 years
Gross Carrying Amount	$ 443,000	$ 451,000
Accumulated Amortization	436,000	430,000
Net	7,000	21,000
Impairment