Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenue:
Product sales	$ 1,376	$ 1,629	$ 2,220	$ 3,069
Royalties	2,517	1,846	4,683	3,490
Total Revenue	3,893	3,475	6,903	6,559
Cost of revenue:
Product sales	609	708	964	1,252
Royalties	92	90	184	180
Total Cost of revenue	701	798	1,148	1,432
Gross profit	3,192	2,677	5,755	5,127
Operating expenses:
Selling, general and administrative	1,765	1,656	3,526	3,092
Research and development	916	728	1,735	1,544
Total Operating expenses	2,681	2,384	5,261	4,636
Operating income from operations	511	293	494	491
Other, net	0	30	0	33
Income from operations before income taxes	511	323	494	524
Income tax expense	0	0	0	4
Net income	$ 511	$ 323	$ 494	$ 520
Net income per share:
Basic (in dollars per share)	$ 0.10	$ 0.06	$ 0.10	$ 0.10
Diluted (in dollars per share)	$ 0.10	$ 0.06	$ 0.10	$ 0.10
Weighted average number of common shares outstanding:
Basic (in shares)	5,206	5,117	5,194	5,107
Diluted (in shares)	5,219	5,128	5,194	5,107