Balance Sheets - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 8,501,392	$ 5,593,582
Accounts receivable, net of allowance of $379,817 and $93,478 in 2016 and 2015, respectively	4,665,959	6,376,470
Inventories	5,381,103	4,504,282
Prepaid expenses and other current assets	855,295	668,659
Total current assets	19,403,749	17,142,993
Property and equipment, net	1,086,244	1,067,321
Intangible assets, net	436,569	635,889
Other assets	39,241	31,693
Total assets	20,965,803	18,877,896
Current liabilities:
Accounts payable	2,623,010	1,840,135
Accrued liabilities	4,491,164	6,058,390
Deferred revenue	8,751,336	7,445,935
Warrants	19,787,007	794,130
Total current liabilities	35,652,517	16,138,590
Long-term debt		18,080,159
Long-term deferred revenue	522,329	2,009,198
Other liabilities	320,409	275,603
Total liabilities	36,495,255	36,503,550
Convertible Preferred stock:
Convertible Preferred stock, par value $0.001; 10,000,000 shares authorized ; 23,900 shares and zero shares outstanding at 2016 and 2015, respectively	5,960,475
Stockholders' deficit:
Common stock, par value $0.001; 300,000,000 shares authorized, 22,063,582 and 21,551,173, shares issued at 2016 and 2015, respectively	22,064	21,551
Additional paid in capital	449,939,406	448,517,472
Treasury stock, 4,015 shares at 2016 and 2015	(205,999)	(205,999)
Accumulated deficit	(471,245,398)	(465,958,678)
Total stockholders' deficit	(21,489,927)	(17,625,654)
Total liabilities and stockholders' deficit	$ 20,965,803	$ 18,877,896