CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED)
Net sales	$ 6,730	$ 5,947	$ 19,478	$ 15,387
Cost of goods sold	2,642	2,670	8,215	6,887
Gross margin	4,088	3,277	11,263	8,500
Operating expenses:
Research and development	1,730	1,567	5,009	4,763
Selling, general and administrative	2,216	1,810	6,332	5,324
Total operating expenses	3,946	3,377	11,341	10,087
Operating income (loss)	142	(100)	(78)	(1,587)
Non-operating income:
Interest income	8	4	11	13
Foreign currency transaction gain (loss)	(26)	(271)	(64)	(302)
Total non-operating income (loss)	(18)	(267)	(53)	(289)
Income (loss) before income taxes	124	(367)	(131)	(1,876)
Income tax (expense) benefit	(112)	(340)	(219)	(442)
Net income (loss)	$ 12	$ (707)	$ (350)	$ (2,318)
Basic earnings (loss) per share	$ 0.00	$ (0.09)	$ (0.04)	$ (0.28)
Diluted earnings (loss) per share	$ 0.00	$ (0.09)	$ (0.04)	$ (0.28)
Weighted-average basic shares	8,621	8,394	8,519	8,305
Weighted-average diluted shares	8,760	8,394	8,519	8,305