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.
Hutchinson
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Parallel Computational Sciences Department, Sandia National Laboratories, Albuquerque, NM 87185, USA.
Ng
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KT
Shadid
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JN
Nadeem
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A
D000465:Algorithms; D000818:Animals; D016880:Anisotropy; D004285:Dogs; D004553:Electric Conductivity; D004554:Electric Countershock / Q000379:methods*; D017097:Electric Impedance; D004566:Electrodes; D006321:Heart / Q000502:physiology; D007091:Image Processing, Computer-Assisted; D008955:Models, Cardiovascular; D018482:Muscle, Skeletal / Q000502:physiology; D013902:Radiography, Thoracic; D012680:Sensitivity and Specificity