Condensed Consolidated Statement of Cash Flows (Unaudited) - USD ($)	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Operating activities
Net loss	$ 31,905,000	$ 25,866,000
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	2,454,000	1,791,000
Accretion (Amortization) of Discounts and Premiums, Investments	30,000	35,000
Amortization of Debt Issuance Costs and Discounts	493,000	169,000
Stock-based compensation	5,602,000	4,540,000
Provision for Doubtful Accounts	32,000	23,000
Non-cash inventory adjustments	565,000	92,000
Other Operating Activities, Cash Flow Statement	(123,000)	19,000
Increase (Decrease) in Accounts Receivable	(1,795,000)	(1,406,000)
Changes in operating assets and liabilities:
Inventories	(2,563,000)	306,000
Increase (Decrease) in Prepaid Expense and Other Assets	(119,000)	(721,000)
Accounts payable	(3,134,000)	1,289,000
Accrued compensation	(1,170,000)	1,119,000
Other liabilities	(124,000)	303,000
Net cash used in operating activities	(28,167,000)	(15,495,000)
Investing activities
Payments for intellectual property licenses	0	(800,000)
Purchases of property and equipment	(2,535,000)	(2,404,000)
Proceeds from Sale of Available-for-sale Securities	13,896,000	0
Proceeds from Maturities, Prepayments and Calls of Available-for-sale Securities	4,100,000	4,650,000
Payments to Acquire Marketable Securities	(10,496,000)	(2,532,000)
Net cash provided by (used in) investing activities	4,965,000	(1,086,000)
Financing activities
Proceeds from Issuance of Common Stock	86,835,000	449,000
Costs incurred in conjunction with stock issuance	(5,171,000)	0
Repayments of Long-term Debt	(964,000)	(17,000)
Proceeds from Debt, Maturing in More than Three Months	15,000,000	10,000,000
Payments of Debt Issuance Costs	(187,000)	(30,000)
Proceeds from stock option exercises	(170,000)	(352,000)
Net cash provided by financing activities	95,683,000	10,754,000
Effect of Exchange Rate on Cash and Cash Equivalents	(13,000)	3,000
Net increase (decrease) in cash and cash equivalents	72,468,000	(5,824,000)
Cash and cash equivalents at beginning of period	15,959,000	35,385,000
Cash and cash equivalents at end of period	88,427,000	29,561,000
Non-cash investing and financing activities
Transfer of instruments from (to) property and equipment into (from) inventory	(1,534,000)	42,000
Intellectual property acquisitions included in other current liabilities	500,000	0
Supplemental cash flow disclosures
Cash paid for income taxes, net	54,000	13,000
Property and Equipment Costs Incurred but not Paid Included in Other Current Liabilities	713,000	588,000
Proceeds from Interest Received	187,000	51,000
Cash paid for interest	$ 574,000	$ 408,000