摘要
随着生物医疗领域的发展,无线植入式设备发挥着越来越重要的作用,综合考虑电磁波在人体组织中的功率损耗与比吸收率SAR值大小,对于植入式脑电极的频率选择具有重要意义。针对此问题,使用CST软件搭建高精度的人头体素模型,仿真探究400 MHz~6.5 GHz常用人体通信频段电磁波在头部组织中的传输特性,分析电磁场分布、功率密度损耗以及辐射危害SAR值。结果表明,电磁波在人头组织中的路径损耗随着组织深度的增加而变大,3.5 GHz以下频段电磁波信道损耗较小,功率密度在皮下25 mm组织内衰减不超过10 d B。人头组织对不同频率的电磁辐射吸收能力不同,高频电磁波辐射危害整体小于低频电磁波,其中1.8 GHz频段吸收的SAR达到了最大值,为1.71 W/kg。综合考虑功率损耗与电磁辐射危害,植入式脑电极的最优工作频率随植入深度变化,2.45 GHz频段电磁波适合头部皮下5 mm内植入式脑电极,1.8 GHz与400 MHz是皮下15 mm与25 mm处植入式脑电极的最优频率,功率密度相较于2.45 GHz分别增加了9.6%与77.4%。
With the development of biomedical field,wireless implantable devices are playing an increasingly important role.Taking into account the power loss and specific absorption rate(SAR)of electromagnetic waves in human tissues,the selection of frequency for implantable electrodes is of great significance.To address this issue,CST software is used to build a high-precision voxel model of the human head,simulate and explore the transmission characteristics of electromagnetic waves in the commonly used human communication frequency band of 400 MHz~6.5 GHz in the head tissue,analyze the distribution of electromagnetic fields,power density losses,and radiation hazard SAR values.The results show that the path loss of electromagnetic waves in human head increases with the depth of the tissue,and the channel loss in the frequency band below 3.5 GHz is smaller,which power density decreases less than 10 dB in the tissue within 25 mm of the skin.The human tissue has different absorption capabilities for different frequencies of electromagnetic radiation,and the SAR value of high-frequency electromagnetic radiation is generally smaller than that of low-frequency electromagnetic radiation.Among them,the SAR of 1.8 GHz reached the maximum value of 1.71 W/kg.Considering the power loss and electromagnetic radiation hazards,the optimal operating frequency for implantable brain electrodes varies with the depth of implantation.2.45 GHz electromagnetic wave is suitable for implantable electrodes in the subcutaneous tissue within 5 mm of the head,and 1.8 GHz and 400 MHz are the optimal frequencies for implantable electrodes located 15 mm and 25 mm beneath the skin,with the power density increasing by 9.6%and 77.4%compared to 2.45 GHz.
作者
程佳君
陈翰
刘翔宇
秦江帆
Cheng Jiajun;Chen Han;Liu Xiangyu;Qin Jiangfan(School of Instrument Science and Engineering,Southeast University,Nanjing 210096,China)
出处
《电子测量与仪器学报》
CSCD
北大核心
2024年第12期173-180,共8页
Journal of Electronic Measurement and Instrumentation
基金
2022年智能电网保护和运行控制国家重点实验室开放课题(SGNR0000KJJS2302150)项目资助。
关键词
植入式脑电极
无线通信
电磁仿真
功率损耗
比吸收率
implantable brain electrodes
wireless communication
electromagnetic simulation
power loss
SAR
