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5 European patents to be issued on oxygen-measuring instrument (10-6-99)

Five European countries--Denmark, France, Germany, Italy and the United Kingdom--are issuing patents this fall on a portable blood analyzer invented at The University of Texas Health Science Center at San Antonio. The 4-pound, battery-powered instrument, known as an oximeter, measures oxygen, hemoglobin and other substances in blood and is useful for diagnosing problems such as heart defects.

The technology, invented by A.P. Shepherd, Ph.D., and John Steinke, Ph.D., of the Health Science Center's Department of Physiology, is licensed by Avox Systems Inc. of San Antonio. More than 700 hospitals in 18 countries have purchased various models of the oximeter since the first model reached the market six years ago.

"These patents are important to the company and the university," said Dr. Shepherd, who founded Avox Systems in 1976. "They give the university and the licensee the exclusive right, in those countries, to continue the commercial development of this technology."

The oximeters shine light through blood samples at different wavelengths and compute the percentage of absorption of each wavelength. "By measuring how much light is absorbed at each wavelength, we can deduce the percentage of hemoglobin saturated with oxygen and the oxygen content of each blood sample," Dr. Shepherd said.

Three products now on the market are based on this technology. The first is a whole-blood oximeter that is used in cardiac catheterization laboratories to measure oxygen saturation. The second is a portable co-oximeter that makes additional measurements including carboxyhemoglobin, a substance found in the blood of carbon monoxide poisoning victims. The third product is a co-oximetry module that is incorporated into a multi-purpose analyzer manufactured under a sublicense to Instrumentation Laboratory, based in Lexington, Mass., and Milan, Italy.

Conventional co-oximeters stand 2 feet tall, weigh 50 pounds and analyze blood samples in 90 seconds. The Health Science Center inventions perform the same functions in 10 seconds. They also weigh only 4 pounds and cost roughly half as much as conventional instruments. "Because this technology lends itself to miniaturization, we can design small, portable instruments for near-patient testing," Dr. Shepherd said. "Clinicians can use these instruments at the bedside. This gives them information as quickly as possible, which may result in better management decisions and earlier discharge dates for the patients."

Drs. Shepherd and Steinke plan to develop additional instruments from this technology. They are applying for Small Business Innovative Research (SBIR) grants for that purpose, which may result in additional research and development down the road at the Health Science Center.

Contact: Will Sansom