Modeling of epicardial signals in the human body

Epicardial signals are time-varying electric potentials on the outer surface of the heart that originate from a signal inside the heart to trigger the heartbeat. Diagnosis of epicardial signals by medical personnel reveals the health of the heart. Modeling of these signals is important in the inverse problem of electrocardiography. In this paper, we present an inverse technique for computing epicardial signals. We present a finite difference method using Laplace's equation for computing the resistance of an arbitrarily shaped conductor. We demonstrate how this method is useful in modeling the currents inside the body due to static electric fields. By applying this method to a model of the human body, we can develop a network of resistors from the heart to various points on the body surface. From actual electrocardiogram (ECG) measurements at the body surface, we can use the derived network to compute source potentials.