经皮无线供能系统多物理场仿真技术

Multi-physics Simulation Technology of the Transcutaneous Wireless Power Supply System

为了研究人工心脏经皮无线供能系统各电路电量与物理场场量之间的相互关系以及系统生物安全性,提出一种多物理场仿真研究方法。基于COMSOL仿真软件建立了经皮无线供能系统的电-磁-热多物理场耦合模型,模型包括电路模型和几何模型,电路模型主要包括逆变电路、补偿电路和整流滤波电路,几何模型主要包括发射线圈、接收线圈及人体皮肤生物组织模型。通过仿真计算获得经皮无线供能系统在谐振和非谐振状态下各电路的电流、电压波形及生物组织安全性指标比吸收率、场强和温度的数值,并参照国际人体电磁安全和人体生理学标准进行安全性评估。仿真结果表明,系统工作在谐振频率160 kHz时,生物组织最大场强为28.2 V/m,最大比吸收率为0.10 W/kg,最大温度为38.8℃,均小于ICNIRP导则中对应的限值87 V/m、2 W/kg以及生理学上温度限值41℃,且非谐振状态下各安全性指标值均减小。该研究为人工心脏经皮无线供能系统的设计和优化提供了有力的分析工具。

In order to analyze the relationship between the circuit current,voltage and physical field quantities in the transcutaneous wireless power supply system of artificial heart,a multi-physics simulation method was proposed.An electro-magnetic-thermal multi-physics coupling model was established for the transcutaneous wireless power supply system based on COMSOL simulation software.The model included both circuit model and geometric model.The circuit model mainly included inverter circuit,compensation circuit and rectification and filtering circuit.The geometric model mainly comprised a transmitting coil,a receiving coil and a human skin biological tissue model.The current,voltage waveform and biological safety indexes of absorption rate,field strength and temperature va-lues of the transcutaneous wireless power supply system in resonant and non-resonant states were obtained by means of simulation.The biosafety assessment was carried by comparing these indexes with reference values of the international human electromagnetic safety and human physiology standards.The simulation results verified the biosafety of the transcutaneous wireless power supply system.The simulation results show that when the system works at a resonant frequency of 160 kHz,the maximum field strength of biological tissue is 28.2 V/m,the maximum specific absorption rate is 0.10 W/kg,and the maximum temperature is 38.8℃,which are all lower than the corresponding limits of 87 V/m and 2 W/kg in the guidelines for ICNIRP and the physiological temperature limit of 41℃.Moreover,each safety index value decreases under the non-resonant state.This method provides a powerful analysis tool for the design and optimization of the artificial heart transcutaneous wireless power supply system.