Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 18,909	$ 40,302
Marketable securities	50,983	48,206
Accounts Receivable, net	1,650
Interest Receivable	672	664
Inventories	3,113	1,152
Prepaid expenses and other	861	994
Deferred financing costs, current	144	144
Total current assets	76,332	91,462
Property and equipment, net	1,687	1,421
Purchased patents, net	626	683
Other assets	363	334
Deferred financing costs, long-term	53	89
Total assets	79,061	93,989
Current liabilities:
Accounts payable and accrued expenses	10,903	10,666
Deferred product revenue, net	3,551
Deferred licensing revenue	417	508
Secured notes payable, net of discount	12,137	11,809
Total current liabilities	27,008	22,983
Deferred licensing revenue, net of current portion	774	309
Secured notes payable, net of current portion and discount	7,975	11,088
Other non-current liabilities	1,860	1,788
Warrant liability	172	251
Total liabilities	37,789	36,419
Stockholders' equity:
Series A preferred stock, $0.001par value - 65,000,000 shares authorized at March 31, 2013 and December 31, 2012; zero shares issued and outstanding at March 31, 2013 and December 31, 2012
Common stock, $0.001 par value - 130,000,000 shares authorized at March 31, 2013 and December 31, 2012; 30,894,666 and 30,621,869 shares issued and outstanding at March 31, 2013 and December 31, 2012, respectively	31	31
Additional paid-in capital	145,999	143,851
Accumulated other comprehensive loss	(89)	(57)
Accumulated deficit	(104,669)	(86,255)
Total stockholders' equity	41,272	57,570
Total liabilities and stockholders' equity	$ 79,061	$ 93,989