CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED)
Net sales	$ 4,769	$ 6,733	$ 9,734	$ 12,748
Cost of goods sold	2,011	2,896	4,673	5,573
Gross margin	2,758	3,837	5,061	7,175
Operating expenses:
Research and development	1,557	1,673	3,173	3,279
Selling, general and administrative	1,928	2,054	3,976	4,116
Total operating expenses	3,485	3,727	7,149	7,395
Operating income (loss)	(727)	110	(2,088)	(220)
Non-operating income (loss):
Interest income	1	0	2	3
Gain on sale of assets	0	0	57	0
Foreign currency transaction gain (loss)	130	(64)	71	(38)
Total non-operating income (loss)	131	(64)	130	(35)
Income (loss) before income taxes	596	(46)	(1,958)	(255)
Income tax (expense) benefit	(61)	(75)	(519)	(107)
Net income (loss)	$ (657)	$ (29)	$ (2,477)	$ (362)
Basic earnings (loss) per share	$ (0.08)	$ 0.00	$ (0.29)	$ (0.04)
Diluted earnings (loss) per share	$ (0.08)	$ 0.00	$ (0.29)	$ (0.04)
Weighted-average basic shares	8,709	8,517	8,665	8,469
Weighted-average diluted shares	8,709	8,517	8,665	8,469