Consolidated Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities:
Net loss	$ (7,656,110)	$ (6,787,674)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	535,819	733,695
Depreciation and amortization	413,545	378,555
Amortization of premiums and discounts	3,225	1,414
Changes in operating assets and liabilities:
Accounts receivable	(37,737)	(694,369)
Inventories	454,348	(37,074)
Prepaid expenses and other assets	120,544	(684,112)
Deferred costs	(850,113)	205,257
Accounts payable	1,714,501	(392,895)
Accrued expenses and other current liabilities	1,249,595	(1,415,479)
Deferred revenue	88,577	(1,965,551)
Net cash used in operating activities	(3,963,806)	(10,658,233)
Cash flows from investing activities:
Purchases of equipment, molds, furniture and fixtures	(1,766,979)	(1,889,615)
Additions to patent rights	(32,517)	(927,631)
Proceeds from maturities of investment securities	3,000,000	3,000,000
Net cash provided by investing activities	1,200,504	182,754
Cash flows from financing activities:
Taxes paid related to net share settlement of equity awards	(34,476)	(11,277)
Net cash used in financing activities	(34,476)	(11,277)
Effect of exchange rate changes on cash	1,246	891
Net decrease in cash	(2,796,532)	(10,485,865)
Cash:
Beginning of period	32,898,676	34,028,889
End of period	30,102,144	23,543,024
Supplemental disclosure of non-cash investing activities:
Purchases of equipment, molds, furniture and fixtures recorded in accounts payable and accrued expenses	1,505,273	1,754,053
Additions to patent rights recorded in accounts payable and accrued expenses	$ 6,501	$ 32,629