人体植入式电子设备无线传能系统中的电磁辐射安全性研究

发布时间：2018-03-01 03:35

本文关键词： 无线能量传输电磁辐射时域有限差分法比吸收率　出处：《中国海洋大学》2015年硕士论文　论文类型：学位论文

【摘要】：目前,植入式电子设备的广泛应用,给医疗行业在诊断治疗疾病方面带来了空前的进步。之前,很难治愈甚至无法治愈的疾病,因为植入式电子设备的广泛使用而被攻破。为了保证植入式电子设备能够长期、稳定、高效的工作,而采用了无线能量供给(Wireless Power Transmission,WPT)技术为设备进行能量供给。这样系统在为体内的电子设备传输能量时,会产生不断变化的电磁场。进而,电磁场就会导致人体产生一系列异常反应,对人体造成一定的伤害,甚至危及生命。因此,为了保证植入式电子设备能够安全、高效的工作,对处在电磁环境下的人体安全性研究非常重要。为此,本文对植入式电子设备无线传能系统中电磁辐射安全性进行了研究。本文的主要研究工作和创新点总结如下：本研究首先查阅相关文献,总结了电磁辐射对人体作用的表现形式,并对目前国内外对人体在电磁场辐射中的安全性问题研究的进展进行了总结归纳。然后,运用专业电磁仿真软件HFSS对植入式电子设备的线圈和无线传能系统进行了设计仿真。线圈设计采用的是PCB线圈,是为了满足充电系统应尽量小型化的要求。把设计仿真好的无线传能系统分别植入到介质球模型和人体头部模型中,进行仿真实验。其次,针对传统时域有限差分方法在研究植入式电子设备无线传能系统中电磁环境下人体与电磁场相互作用问题时,当同一网格内出现混合介质时,无法得到准确的数据,误差较大。本文通过实验,验证了一种适用于该电磁环境下的FDTD方法。实验中,通过设置两种不同的网格尺寸,即Δx=Δy=Δz=2mm和Δx=Δy=Δz=4mm。实验结果表明,该种FDTD方法与传统FDTD方法相比的精确度较高,并且与商业软件CST实验结果吻合程度较好。最后,把该FDTD方法运用到人体头部模型的仿真实验研究中,通过实验数据对比可以发现,该种FDTD方法和CST软件仿真结果吻合较好,并且在人体头部模型与空气介质的边缘处均可以得到较为准确的SAR数据。并绘制了运用不同方法时人体头部模型内部SAR数据分布对比曲线,验证了该种FDTD方法的适用性。接着,通过改变系统谐振频率,进行了同样的实验,结果表明,该种FDTD方法与CST软件吻合结果较好,且人体头部电磁模型的边缘处也能得到准确的结果。并且,模型内部的SAR值均低于国际安全限制标准,表明了无线能量传输系统为植入式电子设备供电是安全的。
[Abstract]:At present, the widespread use of implantable electronic devices has brought unprecedented progress in the diagnosis and treatment of diseases in the medical industry. It was broken down by the widespread use of implanted electronic devices. In order to ensure the long-term, stable and efficient operation of implanted electronic devices, The wireless Power transmission technology is used to supply the energy for the equipment. When the system transmits energy to the electronic devices in the body, it will produce a constantly changing electromagnetic field. Electromagnetic fields will cause a series of abnormal reactions to the human body, causing certain harm to the human body and even endangering life. Therefore, in order to ensure that implanted electronic devices can work safely and efficiently, It is very important to study the safety of human body in electromagnetic environment. In this paper, the safety of electromagnetic radiation in wireless energy transmission system of implanted electronic devices is studied. The main research work and innovation of this paper are summarized as follows: firstly, the relevant literature is consulted in this study. This paper summarizes the manifestation of electromagnetic radiation on human body, and summarizes the progress of research on the safety of human body in electromagnetic field radiation at home and abroad. The coil and wireless energy transfer system of implanted electronic equipment are designed and simulated by using professional electromagnetic simulation software HFSS. The coil is designed with PCB coil. In order to meet the requirement of miniaturization of charging system, the simulated wireless energy transmission system is implanted into the dielectric sphere model and the human head model respectively, and the simulation experiment is carried out. When the traditional finite difference time-domain (FDTD) method is used to study the interaction between human body and electromagnetic field in the wireless energy transmission system of implanted electronic equipment, when a mixed medium appears in the same grid, the accurate data can not be obtained. The error is large. In this paper, an FDTD method suitable for this electromagnetic environment is verified by experiments. In the experiment, two different mesh sizes, 螖 x = 螖 y = 螖 zn 2mm and 螖 x = 螖 y = 螖 zn 4mm, are set. The experimental results show that, The accuracy of this FDTD method is higher than that of the traditional FDTD method, and it is in good agreement with the commercial software CST experimental results. Finally, the FDTD method is applied to the simulation research of the human head model. By comparing the experimental data, it is found that the FDTD method is in good agreement with the simulation results of CST software. More accurate SAR data can be obtained at both the edge of the human head model and the air medium. The comparison curves of SAR data distribution in the human head model with different methods are drawn to verify the applicability of the FDTD method. By changing the resonant frequency of the system, the same experiment is carried out. The results show that the FDTD method is in good agreement with the CST software, and the accurate results can be obtained at the edge of the electromagnetic model of the human head. The SAR values within the model are lower than the international security limit standard, which indicates that wireless energy transmission system is safe to supply power to implanted electronic equipment.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TH772.2

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