Prediction of Tissue Ablation Zones in Asymmetric High-Frequency Irreversible Electroporation Incorporating Dynamic Conductivity and Dielectric Dispersion.

Abstract

Asymmetric pulse waveforms represent an optimized treatment protocol for high-frequency irreversible electroporation (H-FIRE), offering a lower ablation threshold compared to symmetric waveforms. However, the impact of waveform asymmetry has not been considered in current numerical models aimed at predicting tissue ablation zones. This study aims to develop an asymmetric waveform ablation area prediction model incorporating dynamic conductivity and dielectric dispersion effects (AW-DCDE) to predict ablation zones under varying asymmetric conditions. A linear scaling parameter relating pulse asymmetry to the ablation threshold was integrated into a modified Heaviside conductivity function. Dielectric dispersion was captured via a fourth-order Debye model. Variations in electric field intensity and dielectric dispersion were analyzed at pulse widths of 5 μs and 10 μs across different asymmetry levels. Finally, potato tissue experiments were conducted to validate the AW-DCDE model. Increasing waveform asymmetry leads to a reduction in electric field intensity and polarization current, but a significant expansion of the ablation area. Statistical analysis confirmed no significant difference (p > 0.05) between AW-DCDE predictions and experimental results. Dynamic conductivity was found to have a greater influence on the predicted ablation area than dielectric dispersion. Waveform asymmetry significantly affects ablation area and electrical parameters. The AW DCDE model provides a theoretical framework for optimizing clinical H-FIRE treatment protocols.