Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue:
Total Revenue	$ 3,387	$ 4,225	$ 6,546	$ 7,597
Cost of revenue:
Total Cost of revenue	611	1,199	1,234	1,976
Gross profit	2,776	3,026	5,312	5,621
Operating expenses:
Selling, general and administrative	1,563	1,682	3,472	3,347
Research and development	842	697	1,744	1,317
Restructuring charges	0	0	0	2
Total Operating expenses	2,405	2,379	5,216	4,666
Income from operations before income taxes	371	647	96	955
Income tax expense	221	0	57	0
Net income	$ 150	$ 647	$ 39	$ 955
Net income per share:
Basic (in dollars per share)	$ 0.03	$ 0.12	$ 0.01	$ 0.18
Diluted (in dollars per share)	$ 0.03	$ 0.12	$ 0.01	$ 0.18
Weighted average number of common shares outstanding:
Basic (in shares)	5,296	5,244	5,281	5,234
Diluted (in shares)	5,299	5,259	5,299	5,248
Product sales [Member]
Revenue:
Total Revenue	$ 1,172	$ 2,020	$ 2,222	$ 3,641
Cost of revenue:
Total Cost of revenue	520	1,108	1,051	1,793
Royalties [Member]
Revenue:
Total Revenue	2,215	2,205	4,324	3,956
Cost of revenue:
Total Cost of revenue	$ 91	$ 91	$ 183	$ 183