Condensed Consolidated Statements of Operations (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Net sales	$ 1,180	$ 2,227	$ 3,270	$ 6,588
Cost of sales	2,615	757	6,768	3,622
Gross profit (loss)	(1,435)	1,470	(3,498)	2,966
Operating expenses:
Research and development, net of grants	1,588	593	3,266	2,490
Clinical and regulatory	609	984	1,955	2,543
Selling and marketing	2,262	2,132	6,473	6,425
General and administrative	2,605	2,423	7,635	6,079
Total operating expenses	7,064	6,132	19,329	17,537
Loss from operations	(8,499)	(4,662)	(22,827)	(14,571)
Interest income	11		19	1
Other income (expense), net	(1)	(4)	(1)	25
Net loss	$ (8,489)	$ (4,666)	$ (22,809)	$ (14,545)
Net loss per common share - basic and diluted (in dollars per share)	$ (0.20)	$ (0.13)	$ (0.57)	$ (0.41)
Weighted average common shares outstanding - basic and diluted (in shares)	42,220	35,836	39,929	35,555