改进的电阻抗反投影成像算法  

An improved back-projection algorithm for electrical impedance tomography

作　　者：罗辞勇[1] 朱清友[2] 

机构地区：[1]重庆大学电气工程学院输配电装备及系统安全与新技术国家重点实验室,重庆400030 [2]长江师范学院物理学及电子信息工程系,重庆涪陵408003

出　　处：《重庆大学学报（自然科学版）》2009年第3期243-246,共4页Journal of Chongqing University

基　　金：国家863资助项目(2006AA02Z4B7)

摘　　要：在等位线反投影算法基础上,结合计算机断层成像中均值反投影理论,形成应用于电阻抗成像的改进反投影算法。改进算法以注入电极对中点到测量电极对中点的长度作为投影路径的近似长度,在反投影的过程中考虑投影长度的影响;计算反投影后相对电导率的正负均值;最终的相对电导率值是在反投影结果基础上根据符号减去相应的均值,如果改变符号就令相对值为0。仿真和水槽实验验证均改进电阻抗反投影算法相比于等位线反投影算法可以减小重构图像的星状伪迹。改进电阻抗反投影算法是实用有效的。An improved mean back-projection algorithm based on an isopotential back-projection algorithm of electrical impedance tomography （EIT） is presented by adopting the mean back-projection theory of computer tomography. The distance from the midpoint of an injected electrode pair to the midpoint of a measured electrode pair is taken as approximately the length of the projection routine which is introduced into the back-projection process. The positi＇~e and negative mean values of relative conductivities obtained by back-projection are computed. The final relative conductivities are the differences between the conductivity values obtained by back-projection and the corresponding sign mean value. If the results change sign, they are set to zero. Simulations and phantom experiments show that fewer artifacts are present in images reconstructed by mean back-projection algorithm than those reconstructed using the backprojection algorithm. The improved mean back-projection algorithm is more practical and effective than the back-projection algorithm.

关 键 词：电阻抗成像 逆问题 反投影 伪迹 星状伪迹 

分 类 号：TM152[电气工程—电工理论与新技术]