An inverse finite element method for determining the anisotropic properties of the cornea
An inverse finite element method for determining the anisotropic properties of the cornea
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DOI：
10.1007/s10237-010-0237-3
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发表时间：
2011-06-01
影响因子：
3.5
通讯作者：
Boyce, B. L.
中科院分区：
文献类型：
--
作者：
Nguyen, T. D.;Boyce, B. L.
建立了一种由体外充气实验确定牛角膜各向异性特性的逆有限元方法。本实验利用数字图像相关技术(DIC)测量了角膜在多种压力下的三维表面几何形状和位移场。利用DIC测量的未变形标本的表面几何形状，建立了牛角膜的有限元模型。该模型被应用于确定各向异性超弹性模型的五个参数，该模型最小化了测量和计算的表面位移场之间的误差，并研究了测量的牛充气响应对角膜各向异性特性变化的敏感性。参数优化的结果表明，牛角膜的胶原结构在角膜区表现出高度的各向异性，这与最近的组织学结果一致，并显示出横向各向同性的中央区。参数研究表明，牛角膜对充气实验的反应对基质在低于眼压时的剪切模量、在较高压力下胶原层的性质以及角膜缘区的各向异性程度很敏感。它对中央区域的弱胶原各向异性不敏感。
An inverse finite element method was developed to determine the anisotropic properties of bovine cornea from an in vitro inflation experiment. The experiment used digital image correlation (DIC) to measure the three-dimensional surface geometry and displacement field of the cornea at multiple pressures. A finite element model of a bovine cornea was developed using the DIC measured surface geometry of the undeformed specimen. The model was applied to determine five parameters of an anisotropic hyperelastic model that minimized the error between the measured and computed surface displacement field and to investigate the sensitivity of the measured bovine inflation response to variations in the anisotropic properties of the cornea. The results of the parameter optimization revealed that the collagen structure of bovine cornea exhibited a high degree of anisotropy in the limbus region, which agreed with recent histological findings, and a transversely isotropic central region. The parameter study showed that the bovine corneal response to the inflation experiment was sensitive to the shear modulus of the matrix at pressures below the intraocular pressure, the properties of the collagen lamella at higher pressures, and the degree of anisotropy in the limbus region. It was not sensitive to a weak collagen anisotropy in the central region.