Condensed Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Statement [Abstract]
Revenue	$ 0	$ 0	$ 375	$ 400
Cost of revenue	0	0	(81)	0
Gross margin	0	0	294	400
Operating expenses
Research and development	2,433	2,069	4,772	4,298
General and administrative	1,667	1,506	3,315	3,019
Selling and marketing	347	137	672	403
Total operating expenses	4,447	3,712	8,759	7,720
Loss from operations	(4,447)	(3,712)	(8,465)	(7,320)
Other income (expense)
Interest income	35	3	38	5
Interest expense	(69)	0	(140)	0
Total other income (expense), net	(34)	3	(102)	5
Net loss before income taxes	(4,481)	(3,709)	(8,567)	(7,315)
Provision for income taxes	0	17	0	31
Net loss	$ (4,481)	$ (3,726)	$ (8,567)	$ (7,346)
Net loss per common share, basic	$ (0.20)	$ (0.17)	$ (0.37)	$ (0.33)
Net loss per common share, diluted	$ (0.20)	$ (0.17)	$ (0.37)	$ (0.33)
Weighted average number of common shares outstanding, basic	22,936	22,492	22,894	22,292
Weighted average number of common shares outstanding, diluted	22,936	22,492	22,894	22,292