CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 10,980	$ 5,640
Short-term investments	5,543	14,598
Accounts receivable, net	1,062	729
Inventories	1,369	1,597
Prepaid expenses and other	731	701
Total current assets	19,685	23,265
Property and equipment, net	1,704	1,630
Goodwill	23,134	23,134
Other assets	402	663
Total assets	44,925	48,692
Current liabilities
Accounts payable	684	940
Accrued expenses and other	2,775	2,664
Total current liabilities	3,459	3,604
Convertible notes payable	7,890
Other long-term liabilities	243	247
Total liabilities	11,592	3,851
Commitments and contingencies (Note 4)
Stockholders' equity
Preferred stock, $0.01 par value; 20,000 shares authorized; none issued and outstanding
Common stock, $0.01 par value; 120,000 shares authorized; 65,987 shares and 65,496 shares issued and outstanding at June 30, 2016 and December 31, 2015, respectively	660	655
Additional paid-in capital	227,514	226,174
Accumulated other comprehensive loss		(16)
Accumulated deficit	(194,841)	(181,972)
Total stockholders' equity	33,333	44,841
Total liabilities and stockholders' equity	$ 44,925	$ 48,692