Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 3,373	$ 3,177
Accumulated depreciation	2,872	2,551
Property and equipment, net	501	626
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	333	333
Machinery and laboratory equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	604	593
Office furniture and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	293	293
Computer equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	723	712
Field service units [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 1,420	$ 1,246