Simulation of excitation strategy for electromagnetic tomography system

Based on the electromagnetic induction theory, the process of electromagnetic tomography is described as follows, exciting magnetic field is produced by alternating current which is injected into electromagnetic sensor array at the boundary of object field, and the induced magnetic field, which is affected by exciting magnetic field, is aroused in the electrical or magnetic conductive objects. The exciting and induced magnetic fields superimpose together, and this superposition signal reflects the distribution of conductivity or permeability in the harmonic magnetic field. Through the harmonic field, induced voltage would be acquired from the coils, who act as detected ones. By measuring voltage signal from detected coils at the boundary of object field, the conductivity or permeability information can be accessed and the spatial distribution images of the object space can be reconstructed. Comparing with the compound electrodes excitation strategy from others electrical tomography, distinct excitation strategies are proposed in electromagnetic tomography system. The finite-element simulation software, COMSOL Multiphysics, is used to simulate the output condition of three different strategies, and simulated results provide theoretical basing in system reconstructed optimization.