磁感应断层成像技术(magnetic induction tomography,MIT)是一种非接触、无损害的以人体电导率分布为成像目标的阻抗成像技术。本文提出一种用于MIT技术的图像重建算法——修正的Newton—Raphson(NR)算法。首先,推导并求解MIT的正问题和逆问题。其次,通过对比仿真计算和实际测量的结果证明基于有限元的MIT正问题求解方法的有效性。然后,对测量区域内的电导率扰动成功地进行了仿真图像重建。结果证明,本文提出的修正的NR算法是一种有效的MIT图像重建算法,它的实现为下一步物理模型以及生物体上的MIT成像实验打下了良好基础。
Magnetic induction tomography (MIT) is a contactless and noninvasive imaging technique, which aims to image the conductivity distribution inside a human body. An image reconstruction algorithm for MIT-modified Newton-Raphson (NR) algorithm is presented in this paper. Firstly, the forward problem and inverse problem of MIT were solved. Secondly, the simulated results were compared with the measured ones to validate the effectiveness of the forward problem solving method. Thirdly, images with conductivity perturbations were reconstructed successfully with the modified NR algorithm. Results prove that the modified NR algorithm presented in this paper is an effective image reconstruction algorithm for MIT and a good preparation for future image reconstruction of physical models or biological tissues.