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W. G. Pritchard Lab Seminar: 11:15 AM - 12:15 PM, 106 McAllister Bldg
**Monday April 17, 2006**
Mathematics & Medicine: Transport vs Physiology in the Esophagus
James G. Brasseur
Department of Mechanical Engineering
Penn State University
Abstract:
I shall explore the interface between mathematics and medicine with an
approach in which mathematical models are combined with in vivo data to
generate new data of direct physiological importance. We integrate the
local equations of motion across the esophageal wall to produce global
differential equations with solutions that relate total muscle tension to
intraluminal pressure and geometry. This model is combined with high-
resolution concurrent manometric and fluoroscopic data to predict the
spatio-temporal patterning of wall tension in the esophageal circular
muscle during bolus transport in the esophagus. We further develop a
second model of "passive" wall tension parameterized using mano-
fluoroscopic data in the physiological resting state. The combination of
the two mathematical models with in vivo concurrent manometry and imaging
data generates new data that describes the neurophysiology of the
esophagus and space-time distributions of circular muscle tone during
esophageal peristalsis (contraction). We then reformulate the model and
apply it to the opening of the lower esophageal sphincter in reflux, as an
extension of physiological data to a part of parameter space inaccessible
experimentally. In the process, an important discovery is made with
functional and clinical implications. I hope to convince the audience that
mathematical models can be viewed as extensions of physiological
experiments when properly combined with data, and that such extensions
have the potential to uncover important elements of physiology and
function otherwise unattainable.
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