1/21/00

Adam B. Hose, 334/844-5741

AU PROFESSOR DEVELOPS SENSOR TO MONITOR HEPARIN LEVEL IN BLOOD

AUBURN -- Eric Bakker, an associate professor in Auburn University's Department of Chemistry, has developed a new sensor that will help regulate during surgery the amounts of a natural anticoagulant in the blood known as heparin.

If heparin levels are too high, severe bleeding can occur. To combat the problem, Bakker has developed an electrochemical sensor that detects heparin levels and clotting time more accurately and efficiently than traditional methods.

"Sensors traditionally are not used for this purpose during surgery," he says. "To check the blood clotting time, doctors have to extract a small amount of blood and conduct a clotting time measurement test. This involves waiting and watching the blood until it starts to thicken.

"Our sensor can be used during the surgery to constantly measure the amount of heparin in the blood, so that continuous blood extractions are not necessary."

Bakker's sensor, which can be integrated into the blood loop apparatus, speeds up surgery and eases recovery by eliminating the need for blood extractions to test for clotting problems.

The first generation of the heparin sensor was developed and patented by researchers at the University of Michigan with the Medtronics Hemotech Corporation. Those sensors were effective, but not easily reversed.

"Previous sensors were rather irreversible, requiring prolonged exposure to concentrated saline solution between each measurement, which prevents them from being used for continuous monitoring," said Bakker. "We have improved upon that design and have made the sensor much more reversible."

The sensor works by reading the amount of voltage given off when heparin is extracted into a selective membrane, Bakker said. The amount of voltage that builds up is directly dependent on the amount of heparin in the blood. If levels are too low, heparin can be added. If levels are too high, an antidote can be administered to remove some of the heparin and reverse its effect.

Bakker also said that his design could be conveniently integrated with other sensors to measure small blood electrolytes, since it is based on the same basic technology.

"This sensing approach is the preferred way to measure blood electrolytes, so it is compatible with existing efforts in point-of-care sensing technology," he said.

Bakker has filed the provisional patent application with the university on his invention.

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CONTACT: Bakker, 334/844-6973.