3D Electrical impedance tomography using planar arrays

Abstract

A Three dimensional (3D) electrical impedance tomography (EIT) planar array sensor is established for imaging detection. The advantages of a 3D planar array EIT are that they are low cost, mobile and of a non-invasive nature. The sensor is based on the impedance distribution within a closed domain. However, the inverse problem of EIT planar array is invasive and ill-conditioning. This means that a small error (noise or invalid data) of in the conductivity data can have a detrimental effect on the quality of reconstructed images. The Singular Value Decomposition is used to reduce noisy. In this report, a brief history of EIT and methodology are introduced. and an EIT model is described. In this research, a constant current is inputted and voltage readings are collected on a four-electrode-by-four-electrode array placed on the subsurface of the tank. An Electrical impedance and diffuse optical reconstruction software (EIDORS) project is used to reconstruct images by using electrical boundary measurements. Because of the general nonlinear and ill posed properties of EIT, a finite element forward model and algorithms of total variation are used to solve the forward and inverse problems respectively. In order to achieve a stable and fast image reconstruction process, a redundancy analysis method for EIT data is proposed. According to the redundancy analysis, the collected EIT data is divided into valid and invalid data. When the image is reconstructed from the useful data, singular value decomposition (SVD) is used to evaluate the effectiveness and the sensitivity map. The 3D images are reconstructed by the total variation regularization method. The results are shown by simulation and experimental tests. Through comparison of the reconstructed images of all the collected data and valid data, the quality of reconstructed images is not degraded, and the images reconstruction processing time can also be reduced.

Date of Award	16 Aug 2018
Original language	English
Awarding Institution	University of Bath
Supervisor	Manuchehr Soleimani (Supervisor)