Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 11,398	$ 8,819
Short-term investments	1,679	4,078
Accounts receivable, net of allowances for doubtful accounts and other adjustments of $135 (2016) and $201 (2015)	5,459	8,145
Income tax receivable	13	13
Inventories, net of reserves for excess and obsolete inventory of $145 (2016) and $158 (2015)	27	39
Prepaid expenses and other current assets	899	692
Total current assets	19,475	21,786
Equipment and improvements, net	2,150	2,492
Other assets	196	195
Total assets	21,821	24,473
Current liabilities:
Accounts payable	1,480	1,708
Accrued liabilities	5,539	5,064
Deferred revenue	1,107	440
Total current liabilities	8,126	7,212
Non-current liabilities:
Deferred rent and other long-term liabilities	3,110	3,235
Total non-current liabilities	$ 3,110	$ 3,235
Commitments and contingencies
Stockholders' equity:
Preferred stock, par value $0.001 per share; 5,000,000 shares authorized; none issued or outstanding
Common stock, par value $0.001 per share; 100,000,000 shares authorized; 46,968,272 and 45,729,272 shares issued and outstanding at March 31, 2016 and December 31, 2015, respectively	$ 47	$ 46
Additional paid-in capital	225,129	224,867
Accumulated comprehensive deficit	(214,591)	(210,887)
Total stockholders' equity	10,585	14,026
Total liabilities and stockholders' equity	$ 21,821	$ 24,473