CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED)
Net sales	$ 6,733,000	$ 4,655,000	$ 12,748,000	$ 9,440,000
Cost of goods sold	2,896,000	2,216,000	5,573,000	4,217,000
Gross margin	3,837,000	2,439,000	7,175,000	5,223,000
Operating expenses:
Research and development	1,673,000	1,614,000	3,279,000	3,196,000
Selling, general and administrative	2,054,000	1,703,000	4,116,000	3,514,000
Total operating expenses	3,727,000	3,317,000	7,395,000	6,710,000
Operating income (loss)	110,000	(878,000)	(220,000)	(1,487,000)
Non-operating income:
Interest income	0	1,000	3,000	9,000
Foreign currency transaction gain (loss)	(64,000)	(83,000)	(38,000)	(31,000)
Total non-operating income (loss)	(64,000)	(82,000)	(35,000)	(22,000)
Income (loss) before income taxes	46,000	(960,000)	(255,000)	(1,509,000)
Income tax (expense) benefit	(75,000)	(97,000)	(107,000)	(102,000)
Net income (loss)	$ (29,000)	$ (1,057,000)	$ (362,000)	$ (1,611,000)
Basic earnings (loss) per share	$ 0.00	$ (0.13)	$ (0.04)	$ (0.19)
Diluted earnings (loss) per share	$ 0.00	$ (0.13)	$ (0.04)	$ (0.19)
Weighted-average basic shares	8,517	8,302	8,469	8,261
Weighted-average diluted shares	8,517	8,302	8,469	8,261