Title :
FEM electrode refinement for electrical impedance tomography
Author :
Grychtol, Bartlomiej ; Adler, Aviv
Author_Institution :
Dept. of Med. Phys. in Radiol., German Cancer Res. Center, Heidelberg, Germany
Abstract :
Electrical Impedance Tomography (EIT) reconstructs images of electrical tissue properties within a body from electrical transfer impedance measurements at surface electrodes. Reconstruction of EIT images requires the solution of an inverse problem in soft field tomography, where a sensitivity matrix, J, of the relationship between internal changes and measurements is calculated, and then a pseudo-inverse of J is used to update the image estimate. It is therefore clear that a precise calculation of J is required for solution accuracy. Since it is generally not possible to use analytic solutions, the finite element method (FEM) is typically used. It has generally been recommended in the EIT literature that FEMs be refined near electrodes, since the electric field and sensitivity is largest there. In this paper we analyze the accuracy requirement for FEM refinement near electrodes in EIT and describe a technique to refine arbitrary FEMs.
Keywords :
bioelectric potentials; biological tissues; biomedical electrodes; electric impedance imaging; electric impedance measurement; finite element analysis; image reconstruction; inverse problems; matrix algebra; medical image processing; EIT image reconstruction; FEM electrode refinement; electrical impedance tomography; electrical tissue property; electrical transfer impedance measurement; finite element method; pseudoinverse problem; sensitivity matrix; surface electrode; Accuracy; Current measurement; Electrodes; Finite element analysis; Impedance; Sensitivity; Tomography;
Conference_Titel :
Engineering in Medicine and Biology Society (EMBC), 2013 35th Annual International Conference of the IEEE
Conference_Location :
Osaka
DOI :
10.1109/EMBC.2013.6611026