Business and Liquidity (Details) (USD $)	3 Months Ended		6 Months Ended			1 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 item segment	Jun. 30, 2011	Dec. 31, 2011	Feb. 22, 2011 Convertible Notes	Jul. 31, 2012 Subsequent Event Convertible Notes Second tranche
Business and Liquidity
Period since the entity has begun commercialization outside the United States of its newest product, RenalGuard			4 years
Number of operating segments			1
Loss from continuing operations	$ 1,444,000	$ 541,000	$ 8,222,000	$ 5,560,000
Cash used in operations			1,464,000	2,122,000
Accumulated deficit	106,949,000		106,949,000		98,727,000
Number of independent investigator-sponsored clinical trials			2
Additional capital raised
Additional capital raised through the completion of additional financing by the closing on the second tranche of convertible notes						$ 4,000,000	$ 1,000,000