Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Statement [Abstract]
Revenues	$ 11,001	$ 11,699	$ 32,269	$ 37,108
Cost of revenues (including depreciation of $12, $25, $40, and $85 in the three and nine months ended September 30, 2023 and 2022, respectively)	2,528	3,629	8,400	10,882
Gross profit	8,473	8,070	23,869	26,226
Operating expenses:
Selling and marketing	2,449	2,986	8,631	9,687
Research and development	3,704	7,409	13,276	22,756
General and administrative	2,934	4,208	9,448	11,885
Depreciation and amortization	1,567	1,822	4,872	5,665
Total operating expenses	10,654	16,425	36,227	49,993
Operating loss	(2,181)	(8,355)	(12,358)	(23,767)
Other income (expense):
Change in fair value of warrant and derivative liabilities	73	3,457	3,486	3,457
Loss on derecognition of debt	(1,583)	0	(2,985)	0
Interest expense, net	(1,443)	(896)	(5,740)	(898)
Other income (expense), net	15	9	(62)	(22)
Loss before provision for income taxes	(5,119)	(5,785)	(17,659)	(21,230)
Provision for income tax expense	14	27	25	77
Net loss	$ (5,133)	$ (5,812)	$ (17,684)	$ (21,307)
Loss per share:
Basic (in dollars per share)	$ (0.08)	$ (0.10)	$ (0.28)	$ (0.39)
Diluted (in dollars per share)	$ (0.08)	$ (0.10)	$ (0.28)	$ (0.39)
Weighted average shares outstanding:
Basic (in shares)	67,354	55,722	62,297	55,140
Diluted (in shares)	67,354	55,722	62,297	55,140