A Modified Landweber Iteration Algorithm using Updated Sensitivity Matrix for Electrical Impedance Tomography

Abstract

Electrical impedance tomography (EIT) is a technique to reconstruct the conductivity distribution of an inhomogeneous medium by injecting currents at the boundary of an object and measuring the resulting changes in voltage. The sensitivity matrix of EIT is calculated with a selected reference conductivity distribution, which is time-consuming. However, the sensitivity matrix will change with the media distribution, which results in the quality of the reconstructed image reduction. A modified Landweber iterative algorithm based on updated sensitivity matrix was presented in this paper. The reconstructed image based on conventional Landweber iteration was selected as the initial image for sensitivity matrix update, and the reconstructed images after sensitivity matrix update using different initial images were compared. The effect on the quality of reconstructed images for different times of sensitivity matrix update was also analyzed. Simulation and static test were carried out. Experimental results showed that reconstructed images with higher quality can be obtained.