Multi-parametric Finite Element Simulation on Thermal Effect of Liver Tumor Exposed to High-frequency Nanosecond Pulse Bursts

In order to combine characteristics of traditional irreversible electroporation and nanosesond pulses, and to take full advantages of non thermal treatment of pulsed electric fields, the high-frequency nanosecond pulsed bursts was introduced for tumor ablation, and the thermal effects of it were studied. The temperature and thermal damage of the liver and tumor tissue, which have been punctured one pair of needle electrodes, were simulated by the multi-parameter finite element method. The pulse voltage used in this study ranges from 1 to 4 kV, the pulse width ranges from 50 to 500 ns, and the repetition frequency is between 100 kHz and 1 MHz. The total pulse length is 100 μs, and the pulse burst repetition frequency is 1 Hz. The temperature under the thermocouple coupling was calculated using the Pennes biological heat transfer equation, and the thermal damage was calculate according to the Arrhenius formula. The research results indicated that the maximum temperature of the tumor reached at 100 μs was 49.26℃ under the single pulse train; the maximum temperature was 40.4℃ at 1 s, and the cumulative degree of thermal damage after 1 s was only 0.001 6, it will not cause thermal damage. By parameter fitting, the maximum and final temperatures under any parameter combinations can be obtained. These results can provide theoretical basis of pulse parameter selection for future experimental researches. © 2017, High Voltage Engineering Editorial Department of CEPRI. All right reserved.