磁感应方法检测脑组织电导率的FDTD仿真研究

Simulation Study of Detecting the Conductivity of Brain Tissues with Magnetic Induction Based on FDTD

为进一步优化和改进MIT(magneticinductiontomography,MIT)实验系统,采用FDTD(finitedifferencetimedomain)方法,对MIT单通道测量系统进行仿真研究。根据天线理论,将激励线圈近似为螺线管,模拟为一系列电磁源。脑模型考虑颅骨、脑脊液、脑组织和水肿。在10MHz频率,测量与激励线圈同轴时,对自由空间、均匀脑模型、三层脑模型和含水肿的三层脑模型进行仿真计算,获得了上述四种情况下测量线圈上的电流值和激励电流与测量电流的相位差值。

To further optimization and improvement of our MIT experiment system, the simulation study of the ideal physical model of our single channel measurement system of MIT was carried out with finite difference time domain （FDTD） method. According to the antenna theory, an excitation coil similar to a helix was modeled as a stack of electric and magnetic sources. The brain model considers the skull, the cerebrospinal fluid, the brain tissue and an edema. The Air, the homogeneous head model, the three-layer head model, and the three-layer head model with brain edema were simulated with FDTD. The current magnitude of the receiver coil and the phase deviation between the excitation and the receiver coils were calculated under four models when using our coaxial coil system at 10 MHz.