A ROBUST IMAGE-RECONSTRUCTION ALGORITHM AND ITS PARALLEL IMPLEMENTATION IN ELECTRICAL-IMPEDANCE TOMOGRAPHY

We have developed an efficient and robust image reconstruction algorithm for static impedance imaging using Hachtel's augmented matrix method. This improved Newton-Raphson method produced more accurate images by reducing the undesirable effects of the ill-conditioned Hessian matrix. We demonstrated that our electrical impedance tomography (EIT) system could produce two-dimensional static images from a physical phantom with 7 percent spatial resolution at the center and 5 percent at the periphery. Static EIT image reconstruction requires a large amount of computation. In order to overcome the limitations on reducing the computation time by algorithmic approaches, we implemented the improved Newton-Raphson algorithm on a parallel computer system and showed that the parallel computation could reduce the computation time from hours to minutes.