Electrical Impedance Tomography Based On A High-Resolution Direction-of-Arrival Estimation Algorithm

Electrical impedance tomography(EIT)is a promising biomedical imaging technology,which is noninvasive,simple and cheap.Applying excitation current to the electrode placed on the biological surface,the electrical conductivity distribution image of the measured organism is reconstructed on the computer by the reconstruction algorithm,so as to obtain the pathological information of the organism tissues and organs.Currently,the mainly problems of EIT is low image resolution and poor imaging quality.Therefore,this paper focuses on improving EIT image resolution,and proposes an EIT technology based on a high-resolution Direction-of-Arrival(DOA)estimation algorithm to improve.The specific work is to incorporate the DOA theory into EIT model,which provides new ideas for solving the EIT inverse problem and improving the EIT image resolution.The main works and results are as follows:(1)This paper introduces the mathematical model of DOA estimation technology,and the related DOA estimation algorithm is introduced and derived in detail.At the same time,proposes an EIT technology based on DOA estimation algorithm,and studies the signal model and the solution process of the problem in detail.(2)The m-Capon algorithm proposed in this paper,which with highresolution and does not need to estimate the number of sources,is applied to localize the impedance changing region.The simulation of m-Capon imaging algorithm is implemented on EIDORS software,a simulation platform based on MATLAB.Then introduces image evaluation functions such as resolutionfunction,image quality function,correlation function.Comparing m-Capon algorithm with the Equipotential Back-Projection algorithm,Gauss-Newton algorithm and Multiple Signal Classification-like algorithm under different EIT models and different Signal to Noise Ratio.The simulation results show that the EIT technology based on DOA estimation algorithm proposed in this paper is feasible.And the m-Capon imaging algorithm proposes in this paper has better resolution,stronger anti-jamming ability,higher image quality and correlation than the Equipotential Back-projection algorithm,Gauss-Newton algorithm and Multiple Signal Classification-like algorithm.