Electrical defibrillation optimization: An automated, iterative parallel finite-element approach

To date, optimization of electrode systems for electrical defibrillation has been limited to hand-selected electrode configurations, In this paper we present an automated approach which combines detailed, three-dimensional (3-D) finite-element torso models with optimization techniques to provide a flexible analysis and design tool for electrical defibrillation optimization, Specifically, a parallel direct search (PDS) optimization technique is used with a representative objective function to find an electrode configuration which corresponds to the satisfaction of a postulated defibrillation criterion with a minimum amount of power and a low possibility of myocardium damage, For adequate representation of the thoracic inhomogeneities, 3-D finite-element torso models are used in the objective function computations, The CPU-intensive finite-element calculations required for the objective function evaluation have been implemented on a message-passing parallel computer in order to complete the optimization calculations in a timely manner, To illustrate the optimization procedure, it has been applied to a representative electrode configuration for transmyocardial defibrillation, namely the subcutaneous patch-right ventricular catheter (SP-RVC) system, Sensitivity of the optimal solutions to various tissue conductivities has been studied, Results for the optimization of defibrillation systems are presented which demonstrate the feasibility of the approach.