Thin domain wide electrode (TDWE) phantoms for Electrical Impedance Tomography (EIT)

Abstract

Electrical Impedance Tomography (EIT) is a nonlinear ill posed inverse problem which is very prone to modeling errors. 2D-EIT reconstructs the spatial distribution of the object impedance profile comparing the measurements of boundary voltage data collected from a 3D object with the calculated data generated from an absolute 2D domain in computer. As the 2D-EIT assumes current conduction in two dimensional plane of EIT electrode array, the 2D EIT systems working with a practical 3D phantom produce some error and hence the forward modeling should be modified accordingly. On the other hand, the 3D error can be reduced by using long electrodes but in long electrode system, the electrode to electrode gap (EEGR) ratio required to be maintained to attain a good sensitivity is found difficult. In this direction the thin domain wide electrode (TDWE) phantoms are proposed for electrical impedance tomography (EIT) to reduce the 3D error by maintaining the required EEGR. A LabVIEW based multifrequency EIT instrumentation has been developed and a number of TDWE phantoms with different inhomogeneity configurations have been studied. Absolute impedance images reconstructed in EIDORS, demonstrate that developed TDWE phantom improves image quality by reducing the 3D error.