Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Revenues:
Product sales	$ 7,481	$ 7,381
Other revenue	568	348
Total revenues	8,049	7,729
Cost of revenues
Products and services	4,315	4,987
Product line exit expense	0	747
Total cost of revenues	4,315	5,734
Gross profit	3,734	1,995
Operating expenses:
Selling, general and administrative	16,386	20,276
Research and development	5,078	6,214
Total operating expenses	21,464	26,490
Loss from operations	(17,730)	(24,495)
Other income (expense):
Investment income	52	31
Other	61	15
Nonoperating Income (Expense), Total	113	46
Net loss	$ (17,617)	$ (24,449)
Net loss per basic and diluted common share (in dollars per share)	$ (0.43)	$ (0.62)
Weighted average common shares used to compute net loss per basic and diluted common share (in shares)	41,174,812	39,281,620
Comprehensive loss:
Net loss	$ (17,617)	$ (24,449)
Net unrealized gain (loss) on short-term investments	100	(21)
Comprehensive loss	$ (17,517)	$ (24,470)