A Modified Perturbation Method for Three-dimensional Time Harmonic Impedance Tomography

摘要

A reconstruction algorithm for three dimensional time harmonic impedance imaging based on the Modified Perturbation Method (MPM), is proposed. Both the object conductivity (σ) and permittivity (ε) are reconstructed. The original Perturbation method developed for static problems was modified in order to apply in time harmonic problem in higher frequency. In this case complex permittivity and complex voltages are involved. So,major modifications have been made in order to achieve accepted results. The jacobian matrix is expressed in complex form and the modified perturbation reconstruction algorithm formulated accordingly. A number of successful reconstructions were carried out for different complex permittivity profiles,but all of them based on a computer phantom approach.