Analysis Of Sensitivity Field For Electromagnetic Tomography And Study Of Image Reconstruction Algorithm

Electromagnetic tomography technology is a new kind of process tomography technology based on the principle of electromagnetic induction. Its working principle is that the image of distribution for object in the searched space is reconstructed by the voltage of the magnetic field boundaries. The electromagnetic field is distorted by the introduction of magnetic or conductive materials when object is in electromagnetic field. Because of the sensitivity to magnetic or conductive materials, electromagnetic tomography has "dual-mode" imaging characteristics. It causes strong interests and a wide range of concerns from lots of scientists as soon as electromagnetic tomography.Electromagnetic tomography has a lot of advantages for example non-contact, non-intervention, non-injury and so on. Because of electromagnetic waves with the spread of a long-distance communication, penetrating ability and low radiation, electromagnetic tomography will be used for chemical detection, metallurgy, mining, biomedical, geophysical recognition and it has broad prospects for development. Since it has the low price, "dual-mode" and the advantage are concerned above paragraphs.The model in this thesis has eight coils. And each one is excited coil by turns as the model simulation. This thesis sets up the mathematical model for the electromagnetic tomography and analyzes the relations between the forward problem and inverse problem. This thesis analyzes electromagnetic tomography sensitive field by Ansoft software and analyzes the impact to sensitive field from the different materials and incentive coil. This paper focuses on an analysis of the impact to detect voltages.The field is carried out to be subdivided by the use of finite element method and MATALAB software in the paper. And the electromagnetic tomography mathematical model is to solve the forward problem. Image is reconstructed by simulated annealing algorithm. By comparing simulated annealing algorithm and linear back projection algorithm based on sensitivity coefficients, the simulated annealing algorithm is feasible to image reconstruction.