Study of algebraic reconstruction algorithms for practical applications of EII

Abstract

ABSTRACT STUDY OF ALGEBRAIC RECONSTRUCTION ALGORITHMS FOR PRACTICAL APPLICATIONS OF EI I GENCER, Nevzat G. M.S. in Electrical and Electronics Engineering Supervisor: Assoc. Prof. Dr. Ziya IDER February 1988, 169 pages In this study, hardware implementation and image reconstruction algorithms of an Electrical Impedance Imaging System are realized. The nonlinear problem is linearized around an initial conductivity distribution and a linear system of equation is obtained. For the solution of this system some iterative and direct inversion techniques are used. The performance of these techniques are investigated in the aspects of their accuracy and computation times, using collected real data and with simulations. A grouping algorithm is developed to reduce the order of the problem assuming internal object boundary information is available. Iteratively used direct inversion algorithms are made faster, making use of an average value correction technique. The sensitivity of reconstuction algorithms with respect to electrode positions is examined. For the effects of 3-D conductivity distribution on the boundary data, a correction technique is developed. Key words: Imaging, Electrical Impedance Imaging, Finite Element Method -ii-