Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net loss	$ (19,838,556)	$ (14,032,361)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	1,886,823	2,649,062
Depreciation and amortization	1,371,538	1,169,745
Loss on disposal of equipment	17,785	167,097
Amortization of premiums and discounts	10,913	7,070
Changes in operating assets and liabilities:
Accounts receivable	(624,232)	(3,045,011)
Inventories	(999,158)	202,588
Prepaid expenses and other assets	2,922,527	316,315
Deferred costs	(762,413)	1,394,545
Accounts payable	3,308,607	(5,742,113)
Accrued expenses and other current liabilities	(146,376)	236,434
Deferred revenue	1,156,309	(9,173,966)
Net cash used in operating activities	(11,696,233)	(25,850,595)
Cash flows from investing activities:
Purchases of equipment, molds, furniture and fixtures	(4,278,643)	(5,013,012)
Additions to patent rights	(103,788)	(1,008,363)
Proceeds from maturities of investment securities	12,000,000	6,000,000
Purchases of investment securities		(15,037,675)
Net cash provided by (used in) investing activities	7,617,569	(15,059,050)
Cash flows from financing activities:
Proceeds from issuance of common stock, net		42,850,677
Proceeds from exercise of stock options and warrants	24,071
Taxes paid related to net share settlement of equity awards	(64,096)	(87,770)
Net cash provided by (used in) financing activities	(40,025)	42,762,907
Effect of exchange rate changes on cash	1,440	(1,193)
Net increase (decrease) in cash	(4,117,249)	1,852,069
Cash:
Beginning of period	32,898,676	34,028,889
End of period	28,781,427	35,880,958
Supplemental disclosure of non-cash investing activities:
Purchases of equipment, molds, furniture and fixtures recorded in accounts payable and accrued expenses	552,556	$ 42,758
Additions to patent rights recorded in accounts payable and accrued expenses	$ 23,369