Individualized modeling of the heart and torso for finite element method to be used in forward calculation of body surface map

In order to build a torso-heart model to be used in forward calculation of the body surface potential electrocardiogram, a finite-element model for the torso and the heart was designed and adjusted by a computer to fit individuals with different shapes. The basic structure consisted of an innermost sphere (the location of cardiac electromotive force), an outermost surface (corresponding to the torso surface in general), 98 lines radiating from the center of the innermost sphere, and nine surfaces intervening between the above two surfaces. Using these surfaces and lines, the total volume of the torso was divided into 4992 tetrahedrons, whose apices were used as nodes in a finite-element calculation. In adjusting this basic structure to an individual body build, the locations of 98 points over the real body surface were obtained by TV camera and expressed in three-dimensional coordinates. However the basic structure was retained throughout this adjustment procedure, and thus the same computational process could be applied