CONSOLIDATED STATEMENTS OF OPERATIONS (in thousands, except per share amounts) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Net sales	$ 4,655	$ 5,834	$ 9,440	$ 11,892
Cost of goods sold	2,216	2,250	4,217	4,623
Gross margin	2,439	3,584	5,223	7,269
OPERATING EXPENSES:
Research and development	1,614	1,680	3,196	3,361
Selling, general and administrative	1,703	1,829	3,514	3,803
Total operating expenses	3,317	3,509	6,710	7,164
Operating income (loss)	(878)	75	(1,487)	105
NON-OPERATING INCOME (LOSS):
Interest income	1	10	9	22
Gain on sale of assets	0	0	0	60
Foreign currency transaction gain (loss)	(83)	69	(31)	(36)
Total non-operating income (loss)	(82)	79	(22)	46
Income (loss) before income taxes	(960)	154	(1,509)	151
Income tax (expense) benefit	(97)	(27)	(102)	2
Net income (loss)	$ (1,057)	$ 127	$ (1,611)	$ 153
Basic earnings (loss) per share	$ (0.13)	$ 0.02	$ (0.19)	$ 0.02
Diluted earnings (loss) per share	$ (0.13)	$ 0.02	$ (0.19)	$ 0.02
Weighted-average basic shares (in thousands)	8,302	8,257	8,261	8,280
Weighted-average diluted shares (in thousands)	8,302	8,332	8,261	8,375