Balance Sheets - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 3,611,949	$ 3,949,135
Accounts receivable, net	984,515	738,729
Inventories	1,477,327	1,252,238
Prepaid expenses and other current assets	1,719,996	1,646,821
Total current assets	7,793,787	7,586,923
Fixed assets, net	444,321	532,706
Other long-term assets	144,551	164,262
Total assets	8,382,659	8,283,891
Current liabilities:
Accounts payable	758,208	734,048
Accrued compensation	505,553	307,471
Accrued expenses	1,746,556	1,648,731
Deferred revenue	659,273	628,236
Total current liabilities	3,669,590	3,318,486
Common stock warrants	41,099	4,641
Total liabilities	3,710,689	3,323,127
Commitments and contingencies
Stockholders’ equity:
Common stock, $0.0001 par value; 100,000,000 shares authorized at June 30, 2017 and December 31, 2016; 1,650,519 and 836,862 shares issued and outstanding at June 30, 2017 and December 31, 2016, respectively	165	84
Additional paid-in capital	189,620,780	183,439,463
Accumulated deficit	(184,948,997)	(178,478,801)
Total stockholders’ equity	4,671,970	4,960,764
Total liabilities and stockholders’ equity	8,382,659	8,283,891
Non-Convertible Preferred Stock
Stockholders’ equity:
Preferred stock	0	0
Convertible preferred stock
Stockholders’ equity:
Preferred stock	$ 22	$ 18