Conductivity Variation during Irreversible Electroporation

Irreversible electroporation (IRE) is an emerging tumour ablation technique, which utilizes non thermoelectric pulse to ablate tumours. Compared with the common tumour treatment methods, e.g., surgery, chemotherapy and radiotherapy, IRE has advantages of short action time, no massive bleeding of tissue during ablation, avoiding heat sink effect, etc. However, the process of IRE will be affected by the distribution of E-field of the tissue. The major factors which affect E-field distribution are parameters of the electrical pulse and characteristics of the tissue, e.g., the conductivity of the tissue. We utilized the finite element analysis software COMSOL Multiphysics 5.4 to calculate the variation in liver tissue conductivity during IRE. In this study, there is a Low-Voltage High-Frequency (LVHF) pulse involves 3500 unipolar and bipolar pulses, and a High-Voltage Low-Frequency (HVLF) pulse involves eight unipolar and bipolar pulses. The results show that the conductivity change of the HVLF pulse is higher than that of the LVHF pulse due to the higher strength of E-field. The most important conclusion is that the LVHF pulse can only change the tissue conductivity near the electrode tip. The HVLF pulse will significantly change the conductivity in the tissue between the electrodes.