Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2021

Property, Plant and Equipment [Abstract]

Schedule of property and equipment

		December 31,
	Useful Life	2021		2020
Research and development equipment	5 years	$	1,425	$	1,397
Office and computer equipment	3 years		762		733
Autos	5 years		54		54
Furniture and fixtures	7 years		41		41
Leasehold improvements	*		112		283
Construction in progress			45		115
			2,439		2,623
Less accumulated depreciation and amortization			2,105		2,085
Total property and equipment		$	334	$	538

* Shorter of lease term or estimated useful life