A study of electromagnetic model and image reconstruction algorithm based on the eit system

The aim of EIT (Electrical Impedance Tomography) technology is to reconstruct the impedance distribution of the interested field. In general, the excitation electric field is treated as an electrostatic field at low frequency, in order to investigate the conductivity distribution. An intuitive model of the homogeneous distribution is established in this paper based on the idea of how to describe the electric field lines at low frequency in order to study the distribution of the electric field strength. Using the model, the ill-posedness of the coefficient matrix of the sensitivity map can be explained and some guidance to electrode optimization can also be provided. Through comparison with the results obtained by solving the Laplace equation, the model has been proved. A new way to realize equipotential back-projection (EBP) algorithm is introduced based on the model. A comparison was performed between the EBP algorithm and a FEM technique. Both the real time performance and high resolution of reconstructed images using experiment data have been obtained.