Condensed Consolidated Statements of Operations (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Product revenue	$ 265	$ 447
Cost of product revenue	209	461
Gross profit (loss)	56	(14)
Expenses
Research and development	994	1,772
Sales and marketing	114	538
General and administrative	1,158	1,939
Total expenses	2,266	4,249
Operating loss	(2,210)	(4,263)
Interest and other income (expense)
Interest Income	1	0
Change in fair value of warrants liabilities income (expense)	(69)	1,170
Cease-use expense	(7)	(94)
Other expense	(602)	(2)
Interest and other income (expense), net	(677)	1,074
Net loss	$ (2,887)	$ (3,189)
Net loss per share common share, basic and diluted (in usd per share)	$ (110.00)	$ (220.00)
Weighted-average common shares outstanding used to calculate basic and diluted net loss per common share (in shares)	26,853,433,000	14,796,119,000