Loss Per Share (Tables)

12 Months Ended

Dec. 31, 2013

Computation of Diluted Net Loss Per Share does not Assume Issuance of Common Shares that have an Anti-dilutive Effect on Net Loss Per Share

The computation of diluted net loss per share does not assume the issuance of common shares that have an anti-dilutive effect on net loss per share.

	Year Ended December 31,
	(in thousands, except share and per share amounts)
	2013			2012
Net loss		(12,088	)		(9,675	)
Preferred stock dividends		(867	)		(976	)
Preferred stock accretion		(229	)		(230	)
Warrant modification		(8,763	)		—
Net loss applicable to common stockholders	$	(21,947	)	$	(10,881	)
Basic and diluted net loss per share	$	(1.30	)	$	(0.72	)
Shares used in computing basic and diluted net loss per share		16,874			15,131

Dilutive Shares Which Could Exist Pursuant to Exercise of Outstanding Stock Instruments and Which were not Included in Calculation

Dilutive shares which could exist pursuant to the exercise of outstanding stock instruments and which were not included in the calculation because their affect would have been anti-dilutive are as follows:

	Year Ended December 31,
	2013		2012
	(Shares)		(Shares)
Warrants to purchase shares of common stock		6,035,229		7,424,241
Options to purchase shares of common stock		3,348,705		3,539,961
Shares of common stock issuable upon conversion preferred stock		2,568,771		2,627,110
		11,952,705		13,591,312