Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Sales		$ 113		$ 206
Operating Expenses
Cost of goods sold		238		458
Research and development	$ 6,579	7,882	$ 14,063	12,893
Sales and marketing	373	461	748	867
General and administrative	2,116	1,913	4,096	3,527
Total Operating Expenses	9,068	10,494	18,907	17,745
Operating Loss	(9,068)	(10,381)	(18,907)	(17,539)
Other Expense
Interest Expense, net	(280)	(206)	(561)	(527)
Total Other Expense, net	(280)	(206)	(561)	(527)
Net Loss	(9,348)	(10,587)	(19,468)	(18,066)
Other comprehensive income (loss)	0	0	0	0
Comprehensive loss	$ (9,348)	$ (10,587)	$ (19,468)	$ (18,066)
Net loss per share - basic and diluted	$ (0.14)	$ (0.18)	$ (0.30)	$ (0.33)
Weighted average common shares outstanding - basic and diluted	68,105	59,673	65,937	54,264