Balance Sheets (USD $)	Dec. 31, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 10,290,446	$ 16,986,809
Accounts receivable, net of allowances of $299,914 and $405,965 at December 31, 2011 and 2010, respectively	909,718	1,592,564
Inventories	1,763,700	2,412,805
Prepaid expenses and other current assets	493,421	603,821
Current portion of deferred costs	38,021	81,194
Total current assets	13,495,306	21,677,193
Restricted cash	229,500	408,000
Fixed assets, net	483,530	731,975
Intangible assets, net		210,000
Deferred costs and other long-term assets	12,447	39,261
Total assets	14,220,783	23,066,429
Current liabilities:
Accounts payable	629,215	259,155
Accrued compensation	929,117	683,049
Accrued expenses	1,222,155	1,227,790
Current portion of deferred revenue	212,108	468,324
Current portion of capital lease obligation	20,321	19,093
Total current liabilities	3,012,916	2,657,411
Deferred revenue, net of current portion	101,417	171,797
Capital lease obligation, net of current portion	17,929	38,249
Total liabilities	3,132,262	2,867,457
Commitments and contingencies (Note 10)
Stockholders' equity
Preferred stock, $0.001 par value, 5,000,000 shares authorized, none outstanding
Common stock, $0.0001 par value; 50,000,000 authorized; 3,904,320 and 3,866,256 shares issued and outstanding at December 31, 2011 and 2010, respectively	390	387
Additional paid-in capital	139,673,521	138,802,870
Accumulated deficit	(128,585,390)	(118,604,285)
Total stockholders' equity	11,088,521	20,198,972
Total liabilities and stockholders' equity	$ 14,220,783	$ 23,066,429