Three-dimensional reconstruction algorithm for electrical resistance tomography

Abstract

Electrical resistance tomography (ERT) is an imaging tool for process and clinical applications in which maps of the electric conductivity distribution of a body are formed from the current-to-voltage map of the body's surface. ERT is inherently a three-dimensional problem. The transposition of two-dimensional ERT to three-dimensional (3D) ERT is a challenging task and imposes significant increase in computational power demands and storage requirements. It is demonstrated that 3D ERT is a viable offline technique for use today and can be implemented using a low-cost Pentium PC. The 3D image reconstruction algorithm implemented is based on Newton's method in which optimal experiments are used for the reconstruction process. More importantly, the algorithm incorporates 3D forward modelling, 3D data collection and reconstruction. A 'fast' reconstruction algorithm is also implemented and yields a reduced set of equations which has the advantage of no longer being ill-conditioned at the expense of a loss in image resolution.