【作者】 徐文；

【导师】 刘谦；

【作者基本信息】 华中科技大学 ， 生物医学工程， 2009， 硕士

【摘要】 随着现代技术的发展,电磁波和人类的生活越来越紧密。电磁波对人体的危害性已经被广泛的认同,国际非电离辐射防护委员会ICNIRP(International Commission on Non-Ionizing Radiation Protection)和美国电气电子工程师协会IEEE(Institute of Electrical and Electronics Engineers)均对电磁辐射的防护标准进行了规定。基于数字人体的电磁辐射模拟的意义是建立一个电磁辐射强度和人体吸收剂量之间定量的关系,完善并补充电磁辐射模拟数据集,特别是针对中国人种的部分,同时也为新一代多维可变形性人体计算模型的发展与应用提供了参考。本课题以数字人体数据集为基础,构建数字人体体素数据的电磁辐射模拟系统。系统采用时域有限差分算法(FDTD Finite Difference Time Domain)计算方法,工作系统平台是RHEL(Redhat Enterprise Linux)5.0,使用的FDTD软件是由麻省理工学院(MIT)开发并更新维护的MEEP (MIT Electromagnetic Equation Propagation)开源软件,计算平台是浪潮英信NF520D高性能计算服务器。数据的处理为自编的一些辅助程序主要是c++和Matlab程序。安装并构建了一整套从提取VCH模型到计算比吸收率SAR(Specific Absorption Rate)和局部平均比吸收率LASAR(Local Average SAR)的计算体系。为验证系统的可靠性,分别采用点波源和平面波源验证FDTD算法和吸收层与边界条件,可以观察到电磁波的传播和在边界的吸收,平台实现了手机模型与人体体素模型的输入输出,相信更多复杂的模型都可以以类似方法导入。根据输出的电场分量可以求得SAR的分布并可根据质量分布求得LASAR。更多还原

【Abstract】 As the development of modern technology, electromagnetic radiations are getting closer to human lives. Electromagnetic waves, as a kind of ubiquitous matter, do harm to human health, which is widely accepted by scientists. ICNIRP (International Commission on Non-Ionizing Radiation Protection) and IEEE (Institute of Electrical and Electronics Engineers) both concern about it and make protection standards. Under such circumstance electromagnetic radiation are studied all over the world. The purpose of building this simulation system based on VCH (Visual Chinese Human) voxel model is so important that it builds up relations between the power of electromagnetic radiation and the absorption of such waves in human tissue. And it not only provides datasets of electromagnetic radiation simulation, but also gives instruction in building multidimensional human models.In this research, VCH data is used except for some slight changes. Algorithm is the most popular FDTD (Finite Difference Time Domain) methods, which is overwhelming in bio-tissue simulation. The simulation is executed on INSPUR NF520D computing center, using MEEP (MIT Electromagnetic Equation Propagation) which is support by MIT under RHEL (Redhat Enterprise Linux) 5.0 operation system. Some data processing program are written in C++ or MATLAB to obtain or deal with the statistics. In other words, a whole system of electromagnetic radiation simulation is established, from data acquiring to post processing such as SAR (Specific Absorption Rate) and local-average SAR computing. This system has been validated in many ways to make sure it can work correctly. Point source and plane wave source were used to confirm the setup of source and absorption boundary conditions. VCH voxel model and mobile phone model could be input or output to convince us that any model can be used in the similar way. SAR distribution can be deduced from the output of E fields, and LASAR can be got according to the density of human tissue.更多还原