Anisotropic behaviour of human gallbladder walls

Li, W.G., Hill, N.A. , Ogden, R.W. , Smythe, A., Majeed, A.W., Bird, N. and Luo, X.Y. (2013) Anisotropic behaviour of human gallbladder walls. Journal of the Mechanical Behavior of Biomedical Materials, 20, pp. 363-375. (doi:10.1016/j.jmbbm.2013.02.015)

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Publisher's URL: http://dx.doi.org/10.1016/j.jmbbm.2013.02.015

Abstract

Inverse estimation of biomechanical parameters of soft tissues from non-invasive measurements has clinical significance in patient-specific modelling and disease diagnosis. In this paper, we propose a fully nonlinear approach to estimate the mechanical properties of the human gallbladder wall muscles from in vivo ultrasound images. The iteration method consists of a forward approach, in which the constitutive equation is based on a modified Hozapfel–Gasser–Ogden law initially developed for arteries. Five constitutive parameters describing the two orthogonal families of fibres and the matrix material are determined by comparing the computed displacements with medical images. The optimisation process is carried out using the MATLAB toolbox, a Python code, and the ABAQUS solver. The proposed method is validated with published artery data and subsequently applied to ten human gallbladder samples. Results show that the human gallbladder wall is anisotropic during the passive refilling phase, and that the peak stress is 1.6 times greater than that calculated using linear mechanics. This discrepancy arises because the wall thickness reduces by 1.6 times during the deformation, which is not predicted by conventional linear elasticity. If the change of wall thickness is accounted for, then the linear model can used to predict the gallbladder stress and its correlation with pain. This work provides further understanding of the nonlinear characteristics of human gallbladder.

Item Type:Articles
Additional Information:NOTICE: this is the author’s version of a work that was accepted for publication in Journal of the Mechanical Behavior of Biomedical Materials. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of the Mechanical Behavior of Biomedical Materials 20:363-375 April 2013 DOI:10.1016/j.jmbbm.2013.02.015
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Luo, Professor Xiaoyu and Hill, Professor Nicholas and Li, Dr Wenguang and Ogden, Professor Raymond
Authors: Li, W.G., Hill, N.A., Ogden, R.W., Smythe, A., Majeed, A.W., Bird, N., and Luo, X.Y.
College/School:College of Science and Engineering > School of Mathematics and Statistics > Mathematics
Journal Name:Journal of the Mechanical Behavior of Biomedical Materials
Publisher:Elsevier
ISSN:1751-6161
ISSN (Online):1878-0180
Copyright Holders:Copyright © 2013 Elsevier Ltd.
First Published:First published in Journal of the Mechanical Behavior of Biomedical Materials 20:363-375
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

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