Condensed Consolidated 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	$ 21,398	$ 24,324	$ 60,754	$ 62,202
Cost of sales:
Total cost of sales	6,373	8,911	18,976	21,610
Gross profit	15,025	15,413	41,778	40,592
Operating expenses:
Research and development	8,978	16,195	44,729	42,757
Selling, general and administrative	26,525	19,198	64,347	50,813
Restructuring	1,058	0	1,058	0
Total operating expenses	36,561	35,393	110,134	93,570
Loss from operations	(21,536)	(19,980)	(68,356)	(52,978)
Other income (expense):
Interest expense	(229)	(232)	(680)	(942)
Interest income	465	33	552	142
Other expense, net	(244)	(170)	(209)	(117)
Loss before income taxes	(21,544)	(20,349)	(68,693)	(53,895)
Provision for income taxes	22	54	46	97
Net loss	$ (21,566)	$ (20,403)	$ (68,739)	$ (53,992)
Net loss attributable to common stockholders per share, basic (in dollars per share)	$ (0.32)	$ (0.30)	$ (1.01)	$ (0.81)
Net loss attributable to common stockholders per share, diluted (in dollars per share)	$ (0.32)	$ (0.30)	$ (1.01)	$ (0.81)
Weighted-average shares used in calculating net loss per share, basic (in shares)	68,384,115	67,213,282	68,024,937	66,428,303
Weighted-average shares used in calculating net loss per share, diluted (in shares)	68,384,115	67,213,282	68,024,937	66,428,303
Product revenue
Revenue:
Total revenue	$ 15,946	$ 16,704	$ 35,188	$ 43,258
Cost of sales:
Total cost of sales	4,602	4,797	9,911	11,832
Service revenue
Revenue:
Total revenue	5,452	7,620	25,566	18,944
Cost of sales:
Total cost of sales	$ 1,771	$ 4,114	$ 9,065	$ 9,778