Finite element mapping for efficient image reconstruction in rotational electrical impedance tomography

Abstract

Electrical impedance tomography (EIT) is a label free harmless imaging method capable of imaging differences in electrical conductivity of a sample. In EIT, a low frequency current is injected into the sample, voltage differences on sample surface are measured, and from these measurements, interior conductivity distribution is reconstructed. To increase the accuracy of reconstruction, rotational EIT (rEIT) has been proposed where independent measurements are taken from multiple rotational positions around the sample. However, the benefit of conventional electrode configurations are limited to small number of rotational positions. We have presented an approach called Limited Angle Full Revolution rEIT (LAFR-rEIT) that uses a small number of electrodes and large number of rotational measurement position measurements over 360°. The results are comparable to previous rotational EIT implementations, and furthermore, the limited EIT boundary access provides space for simultaneous attachment of other measurement modalities. On the other hand, the increased number of measurement positions cause an increase in computational complexity, and optimization is required until 3D applications are feasible. This work presents modifications into finite element mesh presentation of the imaging domain and outlines an optimization, that enables sufficiently light rotation for 3D LAFR-rEIT computations.