廣義反投影方法在三維電阻抗成像中的研究及實現(xiàn).pdf

1、河北工業(yè)大學博士學位論文廣義反投影方法在三維電阻抗成像中的研究及實現(xiàn)姓名：王宏斌申請學位級別：博士專業(yè)：電氣工程指導教師：徐桂芝2011-06廣義反投影方法在三維電阻抗成像中的研究及實現(xiàn) ii IMPLEMENTATION AND RESEARCH ON GENERALIZED BACK PROJECTION ALGORITHM IN 3D EIT ABSTRACT Electrical Impedance Tomography (EI

2、T), as a kind of electrical tomography techniques, is one of the significant research projects with the features of non-invasive and functional imaging. EIT attracts much concern from many areas, especially on medical di

3、agnosis and clinical monitoring, since it has many advantages in response speed, simple structure and cost. However, this inverse problem on image reconstruction processes an underdetermined, non-linear and ill-posed nat

4、ure. The reconstructed images are far from clinical requirements in the aspects of accuracy, stability and resolution. In this dissertation a novel approach of EIT reconstruction algorithm named generalized back projecti

5、on algorithm is proposed with the purpose of reducing underdetermined conduction, which establishes imaginary node or imaginary element to extend computation range. The algorithm is verified effectiveness by numerical an

6、d real experiments. This work was supported in part by the National Natural Science Foundation of China under Grant No. 50937005 and No. 51077040. The main works and results are following. 1. Generalized back projection

7、 algorithm is proposed based on node back projection algorithm. The information of arbitrary node can be calculated by establishing imaginary node, so that the reconstructed images contain more information. The results o

8、f numerical experiments and real experiments verify the applicability of the method for improvement of reconstructed images effect compared with conventional back projection algorithm. 2. Based on linearised sensitivity

9、matrix, generalize back projection algorithm is proposed. The imaginary elements are established in the region, so that the information of arbitrary part can be computed to reconstruct more detailed conductivity distribu

10、tion information in the region. For the reconstructed images between adjacent electrode sections are less effective, further improved generalize back projection algorithm is proposed, which establishes a mapping of solvi