title: A computationally efficient method for determining the size and location of myocardial ischemia.
abstract: The purpose of this paper is to introduce a new method for solving the inverse problem of locating ischemic regions in the heart. The electrical activity in the human heart is modeled by the bidomain equations, which can be expanded to compute the potentials on the body surface. The associated inverse problem is to use ECG recordings to gain information about ischemias. We propose an algorithm for doing this, combining the level set method with a simpler minimization problem. Instead of trying to determine the shape, as in the level set method, we simply make the approximation that the ischemia is spherical. The effects of ischemia on the electrical attributes of heart tissue are examined. The new method is tested with computer simulations on synthetic body surface potential maps (BSPMs) in a realistic geometry, using realistic values for the parameters. It is shown to be, in some respects, superior to the level set approach and may be a step toward a practical algorithm useful in medical diagnostics.
authors.affiliation: Simula Research Laboratory, N-1325 Lysaker, Norway. tomassru@simula.no
authors.forename: Tomas Syrstad
authors.initials: TS
authors.lastname: Ruud
authors.forename: Bjørn Fredrik
authors.initials: BF
authors.lastname: Nielsen
authors.forename: Marius
authors.initials: M
authors.lastname: Lysaker
authors.forename: Joakim
authors.initials: J
authors.lastname: Sundnes