Business and Liquidity (Details) (USD $)	0 Months Ended	12 Months Ended
	Feb. 22, 2013	Dec. 31, 2012 item	Dec. 31, 2011	Dec. 31, 2010
Business and Liquidity
Period since the entity has begun commercialization outside the United States of its newest product, RenalGuard		5 years
Number of operating segments		1
Loss from continuing operations		$ 8,387,000	$ 6,990,000
Cash used in operations		3,165,000	3,603,000
Cash and cash equivalents		258,000	2,585,000	1,324,000
Number of independent investigator-sponsored clinical trials		2
Additional capital	$ 4,040,000