基于有限元法的色散球形细胞在纳秒脉冲下的跨膜电位仿真

Simulation of Trans-membrane Potential of Dispersive Spherical Cell with Nanosecond Pulsed Electric Field Based on Finite-element Method

为研究频率色散效应对细胞跨膜电位的影响,采用多物理场仿真软件COMSOL Multiphysics建立球形细胞5层介电模型,分别从频域和时域角度研究纳秒脉冲作用时色散效应对细胞膜跨膜电位的影响规律。结果表明,引入色散效应后细胞膜跨膜电位在107 Hz开始显著大于未包含该效应的结果,且随着频率的增加二者差距不断增大;107 Hz时,引入色散效应的跨膜电位在细胞膜半圆弧长上几乎处处高于未包含该效应的结果;脉宽为600 ns和60 ns的时域纳秒脉冲作用时,引入色散效应的跨膜电位在时间和空间分布上都高于未包含该效应的结果,且随着脉宽的降低,二者差距不断加大。研究结果从理论上证明了只有引入频率色散效应才能正确预测纳秒脉冲的生物电效应以及更好地制定治疗计划。

In order to investigate the effects of dispersion on trans-membrane potential(TMP)of biological cells,five-layer dielectric model of a spherical cell was developed with multi-physics simulation software of COMSOL Multiphysics,and the effects of dispersion on TMP of plasma membrane with nanosecond pulsed electric field(nsPEF)were studied in the frequency domain and the time domain.The simulation results indicate that,from 107 Hz,the TMP of plasma membrane with dispersion will significantly greater than that without dispersion,and the difference will increase with the increase in frequency;significant increase in TMP can be found along almost the whole arc length of plasma membrane with dispersion at 107 Hz;significant increase in TMP is obtained in the temporal and spatial scale with dispersion when nsPEF of 600 ns and 60 ns are applied,and the difference increases with the decrease in pulse duration.The simulation results demonstrate that accurate prediction of bioelectric effects of nsPEF and better development of treatment planning can be obtained only by taking the frequency dispersive effects into consideration.