Balance Sheets - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 3,858,089	$ 5,593,582
Accounts receivable, net of allowance of $251,933 and $93,478 in 2016 and 2015, respectively	5,057,503	6,376,470
Inventories	5,334,687	4,504,282
Prepaid expenses and other current assets	569,825	668,659
Total current assets	14,820,104	17,142,993
Property and equipment, net	857,869	1,067,321
Intangible assets, net	536,229	635,889
Other assets	44,774	31,693
Total assets	16,258,976	18,877,896
Current liabilities:
Short-term debt	3,000,000
Accounts payable	2,427,697	1,840,135
Accrued liabilities	5,431,055	6,058,390
Deferred revenue	7,435,975	7,445,935
Warrants and debt conversion features	627,466	794,130
Total current liabilities	18,922,193	16,138,590
Long-term debt	18,114,408	18,080,159
Long-term deferred revenue	620,945	2,009,198
Other liabilities	270,296	275,603
Total liabilities	37,927,842	36,503,550
Stockholders' deficit:
Preferred stock, par value $0.001; 10,000,000 shares authorized, none outstanding at 2016 and 2015
Common stock, par value $0.001; 300,000,000 shares authorized, 21,846,095 and 21,551,173, shares issued at 2016 and 2015, respectively	21,846	21,551
Additional paid in capital	449,081,382	448,517,472
Treasury stock, 4,015 shares at 2016 and 2015	(205,999)	(205,999)
Accumulated deficit	(470,566,095)	(465,958,678)
Total stockholders' deficit	(21,668,866)	(17,625,654)
Total liabilities and stockholders' deficit	$ 16,258,976	$ 18,877,896