电工技术学报2024，Vol.39Issue(16)：4931-4943,13.DOI:10.19595/j.cnki.1000-6753.tces.230969
基于多频磁负超材料的心脏起搏器无线供能研究
Wireless Energy Supply for Cardiac Pacemaker Based on Multi-Band Magnetic Negative Metamaterial
摘要
Abstract
Magnetic coupled resonant wireless power transfer(MCR-WPT)technology is a safer choice for powering implanted medical devices.However,MCR-WPT systems incorporating traditional metamaterials usually work at a fixed single frequency.When the system operating frequency changes,frequency detuning and electromagnetic leakage are prone to occur.,reducing transmission efficiency.Based on the above problems,this paper designs a multi-frequency magnetic negative metamaterial used in implantable cardiac pacemakers'wireless energy supply system.Adjusting the patch capacitance connected in the elementary coil can realize the operation at 6.78 MHz,8.94 MHz,and 13.56 MHz multi-frequency reduces the impact of frequency detuning,ensuring higher working efficiency while avoiding magnetic field leakage. First,based on the equivalent medium theory of magnetic negative metamaterials,the basic formula for the design of regular octagonal metamaterials was deduced,the multi-band magnetic negative metamaterial(MB-MNG)primitive model was established,the parameters of the metamaterial primitives were determined,and the lumped capacitance value of the series connection between the primitives was determined.The metamaterial primitives have special electromagnetic properties at multiple operating frequencies of 6.78 MHz,8.94 MHz,and 13.56 MHz,changing the direction of the passing magnetic field,laying a theoretical foundation for metamaterials to achieve negative refraction. Secondly,taking the S-S structure as an example,simulation verified that the equivalent magnetic permeability of the metamaterial element in the 6.78 MHz,8.94 MHz,and 13.56 MHz frequency bands is negative and the direction of the magnetic field changes.The designed multi-frequency magnetic negative metamaterial is added to the MCR-WPT system and the magnetic field distribution of the traditional MCR-WPT system is comparatively studied.The simulation results show that after adding the multi-frequency magnetic negative metamaterial array,the transmission efficiency under the three operating frequency bands is 43.2％,60.8％,and 75.9％.Compared with the WPT system without adding metamaterials,the transmission efficiency increases by 14.2％～22.1％.When the receiving coil is horizontally offset,after adding multi-frequency magnetic negative metamaterials,the system can still maintain transmission efficiencies of 19.3％,42.9％,and 56.5％.This shows that the addition of multi-frequency magnetic negative metamaterials improves the transmission performance of the pacemaker wireless power transmission system in the event of horizontal offset and enhances the tolerance of system misalignment. An implantable pacemaker wireless power supply experimental system based on the MB-MNG array was built and compared with the MCR-WPT system adding ferrite sheets and the traditional MCR-WPT system.The experimental results show that when the transmission distance is 20 mm and the operating frequencies are 6.78 MHz,8.94 MHz and 13.56 MHz,the output powers of the MCR-WPT system adding the multi-frequency magnetic negative metamaterial array are 3.29 W,2.77 W and 2.87 respectively.W,the system transmission efficiency is 66.7％,48.6％and 51.9％respectively.Compared with the addition of ferrite sheets and the traditional MCR-WPT system,the transmission efficiency has increased by 11.5％～28.0％and 24.6％～36.5％respectively;in the receiving coil,In the case of horizontal offset,the MCR-WPT system with multi-frequency magnetic negative metamaterial array increased the transmission efficiency by 14.68％～26.27％compared with the traditional system;the temperature rise experiment verified that the maximum temperature rise of the system is 3.3 ℃,which will not pose a threat to human safety.Therefore,the application of the multi-frequency magnetic negative metamaterial array proposed in this article to the implantable pacemaker wireless energy supply system can effectively improve the system transmission efficiency and anti-excursion capability,while reducing magnetic field leakage and ensuring human life safety.关键词
无线供能系统/多频磁负超材料/心脏起搏器/传输性能Key words
Wireless power transfer(WPT)/multi-band magnetic negative metamaterial(MB-MNG)/cardiac pacemakers/transmission performance分类
信息技术与安全科学引用本文复制引用
陈伟华,黄雨琦,闫孝姮,宋佳伟..基于多频磁负超材料的心脏起搏器无线供能研究[J].电工技术学报,2024,39(16):4931-4943,13.基金项目
2020年辽宁省教育厅科学研究青年科技人才"育苗"项目(LJ2020QNL019)、2023年辽宁省教育厅科学技术研究面上项目《基于磁负超材料的心脏起搏器无线供能系统传输特性研究》(JYTMS20230815)资助. （LJ2020QNL019）
