2011.93: Shape Deformation in Two-Dimensional Electrical Impedance Tomography
2011.93: Alistair Boyle, Andy Adler and William R.B. Lionheart (2011) Shape Deformation in Two-Dimensional Electrical Impedance Tomography.
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Electrical Impedance Tomography (EIT) uses mea- surements from surface electrodes to reconstruct an image of the conductivity of the contained medium. However, changes in measurements result from both changes in internal conductivity and changes in the shape of the medium relative to the electrode positions. Failure to account for shape changes results in a conductivity image with significant artifacts. Previous work to address shape changes in EIT has shown that in some cases boundary shape and electrode location can be uniquely deter- mined for isotropic conductivities; however, for geometrically conformal changes, this is not possible. This prior work has shown that the shape change problem can be partially addressed. In this paper, we explore the limits of compensation for boundary movement in EIT, using three approaches: first, a theoretical model was developed to separate a deformation vector field into conformal and non-conformal components, from which the reconstruction limits may be determined; next, finite element models were used to simulate EIT measurements from a domain whose boundary has been deformed; finally, an experimental phantom was constructed from which boundary deformation measurements were acquired. Results, both in simulation and with experimental data, suggest that some electrode movement and boundary distortions can be reconstructed based on conduc- tivity changes alone while reducing image artifacts in the process.
|Item Type:||MIMS Preprint|
|Uncontrolled Keywords:||EIT, shape correction, inverse conductivity problem, conformal map|
|Subjects:||PACS 2003 > 41 Electromagnetism; electron and ion optics|
PACS 2003 > 87 Biological and medical physics
|Deposited By:||Prof WRB Lionheart|
|Deposited On:||18 November 2011|