Three-dimensional reconstruction in electrical impedance tomography

The authors have developed a three-dimensional computer-simulated, electrical impedance tomographic imaging system using the four-electrode measurement technique. The reconstruction process finds the numerical solution of Laplace's equation by using the finite element method and the Newton-Raphson algorithm. A new diagonal electrodes measurement method provides lower error than the usual neighboring electrodes measurement method. For a three-layer, 4×4 model, the number of iterations increased from 3 to 16 as the number of randomly placed, high-resistivity voxels (volume elements) increased from 3 to 18.