Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenue:
Total revenue	$ 7,657	$ 9,106	$ 20,846	$ 26,780
Cost of revenue:
Total cost of revenue	3,090	4,372	6,685	9,498
Gross margin	4,567	4,734	14,161	17,282
Operating expenses:
Research and development	2,818	2,500	8,158	7,584
Sales and marketing	3,111	2,910	9,337	8,902
General and administrative	3,690	3,944	10,986	10,335
Total operating expenses	9,619	9,354	28,481	26,821
Operating loss	(5,052)	(4,620)	(14,320)	(9,539)
Interest income (expense), net	135	1	182	(5)
Gain on extinguishment of debt				2,183
Net loss	(4,917)	(4,619)	(14,138)	(7,361)
Cumulative dividend on convertible preferred stock	(339)	(338)	(1,005)	(1,007)
Net loss attributable to common stockholders	$ (5,256)	$ (4,957)	$ (15,143)	$ (8,368)
Net loss per share attributable to common stockholders:
Basic	$ (0.07)	$ (0.07)	$ (0.20)	$ (0.11)
Diluted	$ (0.07)	$ (0.07)	$ (0.20)	$ (0.11)
Weighted average number of common shares and equivalents:
Basic	76,100,007	75,700,389	75,977,920	75,476,381
Diluted	76,100,007	75,700,389	75,977,920	75,476,381
Systems [Member]
Revenue:
Total revenue	$ 2,413	$ 3,541	$ 4,649	$ 8,829
Cost of revenue:
Total cost of revenue	2,016	3,375	3,817	6,200
Disposables Service And Accessories [Member]
Revenue:
Total revenue	5,244	5,319	16,197	17,211
Cost of revenue:
Total cost of revenue	1,074	751	2,868	2,558
Sublease [Member]
Revenue:
Total revenue		246		740
Cost of revenue:
Total cost of revenue		$ 246		$ 740