Analysis of two fixed mesh methods for water vaporization formulation in the modeling of radiofrequency ablation of biological tissues

Abstract

In this study we compared two fixed mesh methods of modeling the electrical and thermal effects produced by water vaporization: the enthalpy method and the water fraction method in radiofrequency ablation (RFA). The results showed the performance of both methods to be qualitatively similar in terms of temperature distributions and impedance evolution. The main difference between the methods was the time at which impedance started to rise. Results suggest that the two methods offer equivalent results in RFA modeling. However, since the enthalpy method has one less problem to be solved (dynamic volume fraction of liquid water in the tissue) it is less complex, has a lower computational cost and therefore seems to be more suitable for modeling RFA with dry or internally cooled electrodes, i.e. those in which there is no interstitial saline infusion.