Note 3 - Balance Sheet Details - Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Property and equipment, gross	$ 1,040	$ 1,244
Less accumulated depreciation and amortization	(908)	(1,132)
Property and equipment, net	132	112
Leasehold Improvements [Member]
Property and equipment, gross	162	114
Furniture and Fixtures [Member]
Property and equipment, gross	268	286
Machinery and Equipment [Member]
Property and equipment, gross	$ 610	$ 844

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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