Balance Sheets - USD ($)	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 1,602,951	$ 5,593,582
Accounts receivable, net of allowance of $155,964 and $93,478 in 2016 and 2015, respectively	6,397,660	6,376,470
Inventories	4,446,363	4,504,282
Prepaid expenses and other current assets	1,150,631	668,659
Total current assets	13,597,605	17,142,993
Property and equipment, net	969,927	1,067,321
Intangible assets, net	586,059	635,889
Other assets	32,341	31,693
Total assets	15,185,932	18,877,896
Current liabilities:
Accounts payable	2,042,246	1,840,135
Accrued liabilities	5,245,395	6,058,390
Deferred revenue	6,627,020	7,445,935
Warrants and debt conversion features	762,836	794,130
Total current liabilities	14,677,497	16,138,590
Long-term debt	18,078,308	18,080,159
Long-term deferred revenue	1,782,155	2,009,198
Other liabilities	270,433	275,603
Total liabilities	$ 34,808,393	$ 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, 21,738,923 and 21,551,173 shares issued at 2016 and 2015, respectively	$ 21,739	$ 21,551
Additional paid in capital	448,794,778	448,517,472
Treasury stock, 4,015 shares at 2016 and 2015	(205,999)	(205,999)
Accumulated deficit	(468,232,979)	(465,958,678)
Total stockholders' deficit	(19,622,461)	(17,625,654)
Total liabilities and stockholders' deficit	$ 15,185,932	$ 18,877,896