A finite difference heat transfer analysis of a percutaneous transluminal microwave angioplasty system

Finite difference time domain (FDTD) techniques have been developed to calculate the specific absorption rates (SAR) in hyperthermia models. The University of Utah Hyperthermia Research Group has extended these numerical techniques for developing a percutaneous transluminal microwave angioplasty applicator, calculating the SARs produced by a high energy electromagnetic field to remove atherosclerotic plaques in blood vessels. The objective of this research was to derive a method for calculating the bioheat transfer in biological tissue surrounding a microwave angioplasty applicator. A hypothetical model was developed and observations are discussed based on the numerical results of this study. A limited analysis on the thermal effects of microwave pulsing was also completed. Preliminary numerical calculations yielded reasonable results. Experimental laboratory tests are required to validate the accuracy of the numerical results found in this study. Further development of this thermal analysis method may greatly assist in future studies of new applicator configurations to ensure safe atherosclerotic plaque removal and to predict the resulting thermal environments.