PHILADELPHIA – Researchers at the University of Pennsylvania have successfully demonstrated that a bedside monitoring system can help treat stroke patients.

The use of a noninvasive optical device to monitor cerebral blood flow and metabolism in patients with acute stroke, they said, could improve the management of patients with strokes and other brain disorders.

"Our preliminary study demonstrates that blood flow changes can be reliably detected from stroke patients and also suggests that blood flow responses vary significantly from patient to patient," said Turgut Durduran, lead author of the study.

The study is part of a five-year, $2.8 million Bioengineering Research Partnership grant from the National Institutes of Health and the University of Pennsylvania Comprehensive Neuroscience Center.

"Stroke is caused by a reduction in blood flow to the brain, yet brain blood flow is rarely if ever measured in stroke patients because most existing methods to measure blood flow require costly instrumentation that is not portable," said John Detre, a clinical collaborator from the Department of Neurology in the School of Medicine at Penn.
"The ability to quantify tissue hemodynamics at the bedside would provide new opportunities both to learn more about blood-flow changes in patients with acute stroke and to optimize interventions to increase blood flow for individual patients, potentially even allowing these interventions to be administered before the onset of new neurological symptoms,"
 Detre said.

The device, which is being developed by researchers, uses embedded optical probes that are placed over major cortical blood vessels in each hemisphere of the brain. The technology, a diffuse correlation spectroscopy, uses lasers, photon-counting detectors, radio-frequency electronics, data processors and a computer monitor to display images of functional information to physicians and nurses.

"What we have demonstrated is a working prototype of a non-invasive brain probe that uses diffusing light to detect physiological changes such as blood flow, blood-oxygen saturation and hemoglobin concentration to inform clinicians about their treatments," said Arjun Yodh, professor of physics in the School of Arts and Sciences at Penn and principal investigator of the study.