STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Common Stock	Preferred Stock	Additional Paid-in Capital	Accumulated Deficit	Total
Balance at Dec. 31, 2020	$ 1	$ 1	$ 64,716	$ (57,084)	$ 7,634
Balance (in shares) at Dec. 31, 2020	10,130	90
Common stock issued upon settlement of restricted stock units (in shares)	92
Issuance of common stock for services (in shares)	2
Surrender of stock to cover tax liability on settlement of employee stock-based awards			(373)		(373)
Surrender of stock to cover tax liability on settlement of employee stock-based awards (in share)	(16)
Issuance of common stock for cash, net of transaction expenses			16,534		16,534
Issuance of common stock for cash, net of transaction expenses (in shares)	472
Common stock issued upon exercise of warrants and options on a cash basis			148		148
Common stock issued upon exercise of warrants and options on a cash basis (in shares)	22
Common stock issued upon exercise of warrants and options on a cashless basis (in shares)	121
Stock-based compensation			1,781		1,781
Net loss				(2,765)	(2,765)
Balance at Mar. 31, 2021	$ 1	$ 1	82,806	(59,849)	22,959
Balance (in shares) at Mar. 31, 2021	10,823	90
Balance at Dec. 31, 2021	$ 1		88,889	(71,293)	17,597
Balance (in shares) at Dec. 31, 2021	11,435
Common stock issued upon settlement of restricted stock units (in shares)	35
Issuance of common stock for services (in shares)	8
Surrender of stock to cover tax liability on settlement of employee stock-based awards			(25)		(25)
Surrender of stock to cover tax liability on settlement of employee stock-based awards (in share)	(4)
Stock-based compensation			1,145		1,145
Net loss				(3,616)	(3,616)
Balance at Mar. 31, 2022	$ 1		$ 90,009	$ (74,909)	$ 15,101
Balance (in shares) at Mar. 31, 2022	11,474