Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Schedule components of inventory

	December 31,
	2021			2020
Raw materials	$	937		$	950
Work in progress		5			24
Finished goods		88			94
Total inventory		1,030			1,068
Less:
Reserve for obsolete		(29	)		(123	)
Total net inventory	$	1,001		$	945

Schedule of stock-based compensation expense

	Years Ended December 31,
	2021		2020
Research and development	$	3	$	9
General and administrative		762		636
Total stock-based compensation expense	$	765	$	645

Schedule of calculation of diluted loss per share attributable to common stockholders

	December 31,
	2021		2020
Common stock purchase warrants		4,531,447		2,582,697
Restricted stock unit		667		32,072
Common stock options		1,087,820		496,471
Total		5,619,934		3,111,240