August 4, 2006

Nightingale Prize honors VUMC researchers

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William Richards, M.D., left, John Wikswo Jr., Ph.D., and Alan Bradshaw, Ph.D., in front of the device which measures magnetic fields produced in the stomach and small bowel.
Photo by Joel Vaughn

Nightingale Prize honors VUMC researchers

A team of Vanderbilt University researchers has won the 2006 Nightingale Prize from the Institute of Physics and Engineering in Medicine for the best paper published in the journal Medical and Biological Engineering and Computing in 2005.

Their paper, entitled “Vector projection in biomagnetic fields,” describes a new way to process information from the tiny magnetic fields produced by electrical activity in the stomach and small bowel.

The goal is to develop new, noninvasive techniques for diagnosing gastrointestinal diseases such as mesenteric ischemia, caused by lack of blood flow to the intestines, and gastroparesis, paralysis of the muscles of the stomach.

“These diseases change the natural electrical rhythm of the GI tissue,” said L. Alan Bradshaw, Ph.D., assistant professor of Surgery and of Physics & Astronomy, and the paper's lead author.

The researchers use a Superconducting Quantum Interference Device (SQUID) magnetometer to measure changes in the magnetic fields caused by these diseases. The SQUID can detect magnetic fields a million times weaker than the Earth's magnetic field.

The technique also is used to measure magnetic fields from the hearts and brains of adults, children and even fetuses.

In the past, it has been difficult to distinguish the electrical activity of the stomach from that of the small bowel because, while the activities oscillate at different frequencies, the signals overlap when recorded by a single sensor, Bradshaw explained.

The Vanderbilt team developed a method for projecting three recorded magnetic field components or “vectors” into different directions. In this way, “you can separate out the fetal heart signal from the maternal heart when monitoring a pregnancy, and the stomach signal from the small bowel signal in a patient with a gastrointestinal disorder,” he said.

Currently it is difficult to diagnose mesenteric ischemia, a potentially life threatening condition that can cause death of intestinal tissue. The researchers hope their technique will help doctors determine when surgery is necessary to restore blood flow.

Bradshaw's co-authors were:

Andrew Myers, a graduate of Vanderbilt's biomedical engineering program who is now a fourth-year medical student at the University of Tennessee in Memphis;

William Richards, M.D., Ingram Professor of Surgical Sciences and medical director of the Vanderbilt Center for Surgical Weight Loss;

William Drake, M.D., former fellow in pediatric cardiology at Vanderbilt who is now at Children's Mercy Hospital in Kansas City, Mo.; and

John Wikswo Jr., Ph.D., Gordon A. Cain University Professor and director of the Vanderbilt Institute for Integrative Biosystems Research and Education (VIIBRE).

Bradshaw, who directs the Vanderbilt GI Biomagnetism Lab and who is also an associate professor of Physics at Lipscomb University, will receive the award on behalf of the group next month at Cambridge University in England.

The research was supported by grants from the Veterans Affairs Research Service, National Institutes of Health and American Heart Association.

The Nightingale Prize is named for the first editor of the Journal of the International Federation of Medical & Biological Engineering, now known as Medical and Biological Engineering and Computing.