Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Statement [Abstract]
Development revenue	$ 268	$ 880	$ 1,461	$ 1,180
Product revenue	19	917	28	2,136
Contract revenue	324	73	341	355
Total revenue	611	1,870	1,830	3,671
Cost of product revenue	33	837	23	1,501
Cost of contract revenue	135	26	144	163
Total cost of revenue	168	863	167	1,664
Gross margin	443	1,007	1,663	2,007
Research and development expense	2,236	2,339	4,779	4,591
Sales, marketing, general and administrative expense	1,869	2,101	3,828	4,504
Gain on disposal of fixed assets	(28)	0	(28)	(2)
Gain on sale of previously reserved inventory	(228)	(1)	(455)	(6)
Total operating expenses	3,849	4,439	8,124	9,087
Loss from operations	(3,406)	(3,432)	(6,461)	(7,080)
Loss on warrant exchange	0	0	(4,967)	0
Other income (expense)	5	(4)	9	(10)
Net loss	$ (3,401)	$ (3,436)	$ (11,419)	$ (7,090)
Net loss per share - basic and diluted	$ (0.08)	$ (0.13)	$ (0.29)	$ (0.27)
Weighted-average shares outstanding - basic and diluted	43,015	26,493	38,951	25,870