Electrical impedance tomography system using 3D finite element algorithm

A 3D finite element model is used for solving the problem of the nonlinearity and multidimensional distribution of the electric field in the reconstruction of the impedance tomographic image of a conductive object. The boundary values of the problem are the small current injected through the cross-section and the voltage measured around the object. The Newton-Raphson method is used for varying the resistivity distribution to fit the set of the measured voltage. The calculated resistivity of each element can be used to reconstruct the image of the object cross-section. The experimental results with a saline tank phantom show a reduction in the error, compared to the 2D model, due to the position of the electrodes around the object and the distribution of the electric field along the thickness of the object