Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenue:
Total Revenue	$ 3,155	$ 3,272	$ 8,726	$ 10,039
Cost of revenue:
Total Cost of revenue	558	585	1,998	2,118
Gross profit	2,597	2,687	6,728	7,921
Operating expenses:
Selling, general and administrative	1,220	1,334	4,229	4,216
Research and development	581	644	1,535	1,681
Total Operating expenses	1,801	1,978	5,764	5,897
Income from operations	796	709	964	2,024
Other income	10	0	29	925
Investment income (loss)	8	0	(17)	0
Interest expense	(18)	0	(53)	0
Income from operations before income taxes	796	709	923	2,949
Income tax expense	152	96	187	453
Net income	$ 644	$ 613	$ 736	$ 2,496
Net income per share:
Basic (in dollars per share)	$ 0.12	$ 0.11	$ 0.14	$ 0.47
Diluted (in dollars per share)	$ 0.12	$ 0.11	$ 0.14	$ 0.47
Weighted average number of common shares outstanding:
Basic (in shares)	5,391	5,349	5,378	5,338
Diluted (in shares)	5,395	5,361	5,387	5,351
Product sales [Member]
Revenue:
Total Revenue	$ 548	$ 805	$ 2,914	$ 3,273
Cost of revenue:
Total Cost of revenue	453	480	1,683	1,823
Royalties [Member]
Revenue:
Total Revenue	2,607	2,467	5,812	6,766
Cost of revenue:
Total Cost of revenue	$ 105	$ 105	$ 315	$ 295