Electrical Impedance Imaging Algorithms And Matlab Simulation

Electrical impedance tomography can reflect internal structure characteristics of object by its electrical characteristics. In EIT, a group of electrodes were placed on the surface of the object, measure the boundary voltage of the object by injecting frequency and size adjustable micro current. Processing the measured data by using certain reconstruction algorithm can get the internal electrical characteristics of the object, and the electrical characteristics is performed by impedance or conductivity.The paper introduces the principle of electrical resistance tomography technology, base on Matlab platform to complete the EIT image reconstruction. EIT(Forward problem)is the problem with finite element method(FEM) for solving Laplace equations, derivation of variational principles, setting up the finite element equation. Using the finite element software QMG2.02for simulation of mesh partition, and the realization of denser partition for border area. The inverse problem of EIT(Inverse problem)is a nonlinear, based on the Tikhonov regularization technology of modified Newton Raphson iterative algorithm, process the measured data, change the regularization parameter and the number of iterations, observe the imaging result.EIT technology has the characteristics of real-time imaging, give a person auditory stimulation, get Matlab simulation of the internal electrical impedance of the human brain image, found the auditory stimuli instant internal change of the electrical characteristics of the human brain.The cerebral gray matter of the human brain interior surface resistivity is less,white matter resistivity is slightly more.Where nerve fibers (white matter) gathered resistivity is more.