Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenue:
Total revenue	$ 6,152	$ 9,051	$ 13,189	$ 17,674
Cost of revenue:
Total cost of revenue	1,482	2,519	3,595	5,126
Gross margin	4,670	6,532	9,594	12,548
Operating expenses:
Research and development	2,893	2,717	5,340	5,084
Sales and marketing	3,279	3,045	6,225	5,992
General and administrative	3,677	4,161	7,297	6,391
Total operating expenses	9,849	9,923	18,862	17,467
Operating loss	(5,179)	(3,391)	(9,268)	(4,919)
Interest income (expense), net	45	(3)	48	(7)
Gain on extinguishment of debt		2,183		2,183
Net loss	(5,134)	(1,211)	(9,220)	(2,743)
Cumulative dividend on convertible preferred stock	(335)	(335)	(666)	(668)
Net loss attributable to common stockholders	$ (5,469)	$ (1,546)	$ (9,886)	$ (3,411)
Net loss per share attributable to common stockholders:
Basic	$ (0.07)	$ (0.02)	$ (0.13)	$ (0.05)
Diluted	$ (0.07)	$ (0.02)	$ (0.13)	$ (0.05)
Weighted average number of common shares and equivalents:
Basic	75,953,916	75,547,574	75,915,864	75,362,521
Diluted	75,953,916	75,547,574	75,915,864	75,362,521
Systems [Member]
Revenue:
Total revenue	$ 602	$ 2,686	$ 2,236	$ 5,289
Cost of revenue:
Total cost of revenue	509	1,390	1,801	2,825
Disposables Service And Accessories [Member]
Revenue:
Total revenue	5,550	6,118	10,953	11,892
Cost of revenue:
Total cost of revenue	973	882	1,794	1,808
Sublease [Member]
Revenue:
Total revenue		247		493
Cost of revenue:
Total cost of revenue		$ 247		$ 493