摘要
感应式磁声成像(MAT-MI)是一种近年来提出的新型生物电阻抗成像方法,在理论与实验方面仍有很多问题值得研究和探讨,本研究设计仿真实验分析磁声耦合效应产生声源的分布及特点。结合电磁场理论分析MAT-MI声源与电导率分布、激励磁场、静态磁场和感应电场的关系,基于有限元方法构建了三维霍姆赫兹线圈和双层导体立方体的仿真模型,借助有限元分析软件ANSYS进行时变电磁场有限元分析,得到不同电导率导体内部的感应电流分布及声源分布。并应用电磁场分析的结果得到感应涡电流分布及声源分布。仿真结果表明,均匀介质内部和两种不同电导率介质分界面上都存在MAT-MI声源,但感应涡电流密度和声源在电导率边界处变化较大。
Aim-Magneto-acoustic tomography with magnetic induction(MAT-MI) is a recently proposed imaging modality to image the electrical impedance of biological tissue, key points in both of the theory and experiment still require more researches.We implemented simulating experiments to investigate the distribution of the induced current and the acoustic source induced by MAT-MI.The simulating experiments analyzed the relationships of the acoustic source with the electric conductivity of the model,the feature of exciting pulsed magnetic fields,the static magnetic field and the induced electric field were analyzed.A three-dimensional Helmholtz coil and a two-layer conductivity cubic simulating model with different conductivity were set up as well as transient electromagnetic finite element analysis was carried out by using ANSYS FEM software,the distributions of the induced electric current and acoustic source were obtained in the conductors with different conductivity inside the model.The simulation results suggest that acoustic resources are produced inside the homogeneous medium as well as on the conductivity boundary between mediums,however,the induced current and the acoustic source vary rapidly on the boundary between different conductivity compared with that inside cubes and on the boundary of two-layers cubes.
出处
《生物医学工程研究》
2011年第1期1-5,共5页
Journal Of Biomedical Engineering Research
基金
国家自然科学基金资助项目(30770557)
天津市应用基础重点项目(07JCZDJC07000)
天津市应用基础重点资助项目(10JCZDJC17200)
