2008.65: Evaluating Deformation Corrections in Electrical Impedance Tomography
2008.65: Alistair Boyle, William R.B. Lionheart, Camille Gomez-Laberge and Andy Adler (2008) Evaluating Deformation Corrections in Electrical Impedance Tomography. In: 9th EIT conference 2008, 16-18th June 2008, Dartmouth College, New Hampshire.
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Electrical Impedance Tomography (EIT) uses the difference in measurements between surface electrodes to reconstruct an image of the conductivity of the contained medium. However, changes in measurements result from 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: a) theoretically, for an infinite number of electrodes, non-conformal changes in boundary shapes and electrode locations can be uniquely determined (Lionheart, 1998); and b) in some cases, conductivity and shape changes can be recovered using a combined image reconstruction model of both conductivity and shape changes (Soleimani et al, 2006). This 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 is 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 are constructed from which EIT measurements are simulated; finally, an experimental phantom is constructed using a deformable gasket and stainless steel electrodes in a saline medium, from which boundary deformation measurements are acquired.
|Item Type:||Conference or Workshop Item (Paper)|
|Uncontrolled Keywords:||EIT, boundary shape|
|Subjects:||PACS 2003 > 87 Biological and medical physics|
|Deposited By:||Prof WRB Lionheart|
|Deposited On:||26 June 2008|