Note 5 - Property and Equipment, Net - Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property and Equipment	$ 4,446	$ 5,080
Less: Accumulated depreciation and amortization	(4,351)	(4,353)
Total property and equipment, net	95	727
Equipment Held by Customers [Member]
Property and Equipment	2,362	2,746
Machinery and Equipment [Member]
Property and Equipment	1,391	1,679
Software Development [Member]
Property and Equipment	122	122
Computer Equipment [Member]
Property and Equipment	173	144
Furniture and Fixtures [Member]
Property and Equipment	78	78
Leasehold Improvements [Member]
Property and Equipment	$ 320	$ 311

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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