Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue:
Total Revenue	$ 2,979	$ 3,159
Cost of revenue:
Total Cost of revenue	706	623
Gross profit	2,273	2,536
Operating expenses:
Selling, general and administrative	1,366	1,909
Research and development	496	902
Total Operating expenses	1,862	2,811
Income (loss) from operations	411	(275)
Other income, net	925	0
Income (loss) from operations before income taxes	1,336	(275)
Income tax expense (benefit)	205	(164)
Net income (loss)	$ 1,131	$ (111)
Net income (loss) per share:
Basic (in dollars per share)	$ 0.21	$ (0.02)
Diluted (in dollars per share)	$ 0.21	$ (0.02)
Weighted average number of common shares outstanding:
Basic (in shares)	5,322	5,267
Diluted (in shares)	5,342	5,267
Product sales [Member]
Revenue:
Total Revenue	$ 1,163	$ 1,050
Cost of revenue:
Total Cost of revenue	613	531
Royalties [Member]
Revenue:
Total Revenue	1,816	2,109
Cost of revenue:
Total Cost of revenue	$ 93	$ 92