Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue:
Total Revenue	$ 3,372	$ 3,010
Cost of revenue:
Total Cost of revenue	777	447
Gross profit	2,595	2,563
Operating expenses:
Selling, general and administrative	1,665	1,761
Research and development	620	819
Restructuring charges	2	0
Total Operating expenses	2,287	2,580
Operating income (loss) from operations	308	(17)
Income (loss) from operations before income taxes	308	(17)
Income tax expense	0	0
Net income (loss)	$ 308	$ (17)
Net income (loss) per share:
Basic (in dollars per share)	$ 0.06	$ (0.00)
Diluted (in dollars per share)	$ 0.06	$ (0.00)
Weighted average number of common shares outstanding:
Basic (in shares)	5,224	5,181
Diluted (in shares)	5,243	5,181
Product sales [Member]
Revenue:
Total Revenue	$ 1,621	$ 844
Cost of revenue:
Total Cost of revenue	685	355
Royalties [Member]
Revenue:
Total Revenue	1,751	2,166
Cost of revenue:
Total Cost of revenue	$ 92	$ 92