Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Total revenue	$ 8,668	$ 2,107	$ 24,335	$ 4,496
Cost of sales	4,428	2,138	12,986	6,221
Gross profit	4,240	(31)	11,349	(1,725)
Operating expenses:
Research and development	4,919	3,893	13,917	11,732
Selling, general and administrative	12,118	7,054	34,765	21,138
Total operating expenses	17,037	10,947	48,682	32,870
Loss from operations	(12,797)	(10,978)	(37,333)	(34,595)
Interest expense	(1,469)	(1,387)	(4,370)	(3,490)
Interest and other income, net	163	357	198	344
Net loss	$ (14,103)	$ (12,008)	$ (41,505)	$ (37,741)
Net loss per share, basic (in dollars per share)	$ (1.22)	$ (2.77)	$ (5.64)	$ (11.34)
Net loss per share, diluted (in dollars per share)	$ (1.22)	$ (2.77)	$ (5.64)	$ (11.34)
Weighted-average shares used in computing net loss per share attributable to common shareholders
Basic (in shares)	11,580,000	4,329,000	7,361,000	3,327,000
Diluted (in shares)	11,580,000	4,329,000	7,361,000	3,327,000
Other comprehensive loss:
Unrealized (loss) gain on cash equivalents	$ (2)	$ (16)	$ (27)	$ 3
Comprehensive loss	$ (14,105)	$ (12,024)	$ (41,532)	$ (37,738)