Three-dimensional modeling of electrical defibrillation on a massively parallel computer

A finite-element solver for electrical defibrillation analysis has been developed on a massively parallel computer, Thinking Machines Corporation´s Connection Machine 2 (CM-2), which allows a high degree of parallelism and the solution of large problems. The solver uses a nodal assembly technique where each node in the finite-element grid is mapped to a virtual processor in the computer. Using this solver, potential and current density distributions during transthoracic defibrillation have been calculated for different anatomic models, including a realistic 3-D finite-element model constructed from a series of cross-sectional magnetic resonance imaging (MRI) images of a mongrel dog. Numerical results obtained with this model are presented together with computational performance data for the algorithm