CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Cost of revenue	$ 8,111	$ 7,720	$ 16,543	$ 15,050
Gross profit	10,098	7,700	19,170	13,934
Operating expenses:
Research and development	14,417	9,881	27,857	19,318
Selling, general and administrative	16,740	14,437	32,901	28,044
Total operating expenses	31,157	24,318	60,758	47,362
Loss from operations	(16,793)	(12,571)	(32,861)	(25,926)
Non-operating expense, net:
Foreign exchange gain (loss)	105	(138)	(57)	(30)
Interest expense	(1,150)	(958)	(4,074)	(1,873)
Other income, net	337	444	759	775
Total non-operating expense, net	(708)	(652)	(3,372)	(1,128)
Loss before income taxes	(17,501)	(13,223)	(36,233)	(27,054)
Provision for income taxes	61	59	121	113
Net loss	$ (17,562)	$ (13,282)	$ (36,354)	$ (27,167)
Net loss per share:
Basic and diluted	$ (0.13)	$ (0.10)	$ (0.26)	$ (0.21)
Weighted average shares used for calculating net loss per share:
Basic and diluted	138,281	131,352	137,698	128,101
Product
Revenue	$ 18,209	$ 15,420	$ 35,713	$ 28,984
Government Contract
Revenue	$ 4,266	$ 4,047	$ 8,727	$ 7,502