CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Sales
Total sales	$ 3,643	$ 2,330	$ 10,569	$ 8,346
Cost of sales
Total cost of sales	1,735	1,206	5,504	4,623
Gross margin	1,908	1,124	5,065	3,723
Operating Expenses:
Research and development	5,865	5,739	17,394	16,531
General and administrative	4,510	4,615	13,361	16,103
Sales and marketing	2,496	2,529	6,769	7,575
Total operating expenses	12,871	12,883	37,524	40,209
Loss from operations	(10,963)	(11,759)	(32,459)	(36,486)
Interest income	585	1,021	2,056	2,920
Other income (expense), net	52	(19)	73	12
Loss before provision for income taxes	(10,326)	(10,757)	(30,330)	(33,554)
Provision for income taxes	0	0	0	0
Net loss and comprehensive loss	$ (10,326)	$ (10,757)	$ (30,330)	$ (33,554)
Net loss per common share attributable to common stockholders, basic	$ (0.14)	$ (0.15)	$ (0.42)	$ (0.47)
Net loss per common share attributable to common stockholders, diluted	$ (0.14)	$ (0.15)	$ (0.42)	$ (0.47)
Weighted-average shares used to compute net loss per share attributable to common stockholders, basic	72,678,622	71,464,315	72,219,681	71,178,769
Weighted-average shares used to compute net loss per share attributable to common stockholders, diluted	72,678,622	71,464,315	72,219,681	71,178,769
Device
Sales
Total sales	$ 3,033	$ 1,728	$ 8,707	$ 6,670
Cost of sales
Total cost of sales	1,359	835	4,280	3,321
Service
Sales
Total sales	610	602	1,862	1,676
Cost of sales
Total cost of sales	$ 376	$ 371	$ 1,224	$ 1,302