Colorado State University

Problems in Electrical Impedance Tomography

By David Isaacson
From Rensselaer Polytechnic Institute
Troy, NY
When November 16, 2006
3:00 pm
Where Room B4, Engineering Building
Abstract Electrical Impedance Tomography systems apply currents to and measure voltages from an array of electrodes on a portion of the surface of a body. From these measurements an approximate reconstruction and display of the electrical conductivity and permittivity inside the body is made. Since hearts and lungs filled with blood have a higher conducitivity then when they are depleated of blood these impedance images can be used to monitor heart and lung function. Since many breast tumors have a significantly higher conducivity than surrounding normal tissue impedance images may be used to improve the diagnosis of breast cancer. It will be explained how these images are reconstructed by solving inverse boundary value problems for Maxwell's equations. Movies and images of cardiac activity and breast tumors made by our adaptive current tomography systems will be shown. It will be explained how impedance spectroscopy i.e. the frequency dependence of the reconstructed impedances, may be used to help distinguish cancerous from benign lesions.
Further Information Jennifer Müller
The Colloquium counts as Seminar Credit for Mathematics Students.