Property and Equipment - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Property and equipment	$ 2,517	$ 2,028
Less accumulated depreciation	(1,945)	(1,876)
Property and equipment, net	756	832
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment	112	112
Manufacturing Equipment
Property Plant And Equipment [Line Items]
Property and equipment	940	269
Computer and Office Equipment
Property Plant And Equipment [Line Items]
Property and equipment	102	107
System and Laser
Property Plant And Equipment [Line Items]
Property and equipment	1,219	1,452
Software
Property Plant And Equipment [Line Items]
Property and equipment	56
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment	50	50
Transportation Equipment
Property Plant And Equipment [Line Items]
Property and equipment	38	38
Construction in Progress
Property Plant And Equipment [Line Items]
Construction in progress	$ 184	$ 680