Condensed Consolidated Statements of Operations and Comprehensive Loss (unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues:
Product sales	$ 1,852,000	$ 823,000	$ 3,278,000	$ 1,498,000
Other revenue	82,000	10,000	198,000	24,000
Total revenues	1,934,000	833,000	3,476,000	1,522,000
Cost of revenues:
Products and services	1,247,000	565,000	2,184,000	971,000
Product line exit expense	747,000	0	747,000	0
Total cost of revenues	1,994,000	565,000	2,931,000	971,000
Gross profit (loss)	(60,000)	268,000	545,000	551,000
Operating expenses:
Selling, general and administrative	6,579,000	2,538,000	11,557,000	4,678,000
Research and development	1,162,000	577,000	2,227,000	1,111,000
Total operating expenses	7,741,000	3,115,000	13,784,000	5,789,000
Loss from operations	(7,801,000)	(2,847,000)	(13,239,000)	(5,238,000)
Other income (expense):
Investment income	8,000	31,000	10,000	76,000
Other	(6,000)	0	1,000	0
Other income (expense)	2,000	31,000	11,000	76,000
Net loss	$ (7,799,000)	$ (2,816,000)	$ (13,228,000)	$ (5,162,000)
Net loss per basic and diluted common share	$ (0.20)	$ (0.09)	$ (0.35)	$ (0.17)
Weighted average common shares used to compute net loss per basic and diluted common share	38,162,526	31,241,470	37,938,873	30,749,532
Comprehensive loss:
Net loss	$ (7,799,000)	$ (2,816,000)	$ (13,228,000)	$ (5,162,000)
Net unrealized loss on short-term investments	(4,000)	0	(2,000)	0
Comprehensive loss	$ (7,803,000)	$ (2,816,000)	$ (13,230,000)	$ (5,162,000)