A Study of Radiofrequency Cardiac Ablation Using Analytical and Numerical Techniques A Study of Radiofrequency Cardiac Ablation Using Analytical and Numerical Techniques
Studies on radiofrequency (RF) ablation are often aimed at accurately predicting tissue temperature distributions by numerical solution of the bioheat equation. This thesis describes the development of an analytical solution to serve as a benchmark for subsequent numerical solutions. The solution, which was obtained using integral transforms, has the form of a surface integral nested within another surface integral. An integration routine capable of evaluating such integrals was developed and a C program was written to implement this routine. The surface integration routine was validated using a surface integral with a known analytical solution. The routine was, then, used to generate temperature profiles at various times and for different convection coefficients. To further validate the numerical methods used to obtain temperature profiles, a numerical model was developed with the same approximations used in obtaining the analytical solution. Results of the analytical and numerical solutions match very closely.
In addition, three numerical models were developed to assess the validity of some of the assumptions used in obtaining the analytical solution. For each numerical model, one or two of the assumptions used in the analytical model were relaxed to better assess the degree to which they influence results. The results indicate that (1) conduction of heat into the electrode significantly affects lesion size, (2) temperature distributions can be assumed to be axisymmetric, and (3) lesion size and maximum temperature are strongly influenced by the temperature-dependence of electrical conductivity. These conclusions are consistent with results from previous studies on radiofrequency cardiac ablation.
School:Brigham Young University
School Location:USA - Utah
Source Type:Master's Thesis
Keywords:radiofrequency cardiac ablation integral transforms surface integration
Date of Publication:08/04/2003