Simulation Research On Electrical Impedance Endotomography Based On BEM

Electrical impedance endotomography (EIE) technology is a functional imaging technologybased on electrical impedance tomography (EIT) development. In EIE, the electrodes are placedon the probe of the insulated catheter, and the probe is directly inserted into the internal organs ofinterest. Then the excitation currents are injected and the voltages are measured using theelectrodes, and the inner impedance images of the organ can be reconstructed using the voltagedistribution.In this thesis the research situation and imaging principle of EIE are introduced, and thenumerical computation methods of EIE are described firstly. Then the boundary element method(BEM) is studied in details, the boundary integral equation and discrete formula are derived. The2D and3D simulation models are established, the forward computations are taken, and the idealaccuracies are achieved. This is the basis of the inverse problem. Furthermore, the parametricreconstruction thoughts are studied, and the2D ellipse and3D ellipsoid parametric models areestablished, which the models can be described with a few parameters. Finally, the differentialevolution (DE) algorithm are studied and applied in the parametric reconstruction of2D model.The results show that the reconstructions image by the iteration are coincidence with the initialtarget image, which achieving the purpose of localization.