Nonlinear Finite Element Model Analysis Of Human Accommodation Lens

ResearchCommons/Manakin Repository

Nonlinear Finite Element Model Analysis Of Human Accommodation Lens

Show simple item record Le, Tri en_US 2007-08-23T01:56:08Z 2007-08-23T01:56:08Z 2007-08-23T01:56:08Z August 2005 en_US
dc.identifier.other DISS-1049 en_US
dc.description.abstract The crystalline human lens is modeled by using the finite element software, ABAQUS/CAE Version 6.5-1 as an axisymmetric shell to study the optical power and displacement of anterior and posterior poles induced due to zonule traction. Several different element types were tested to obtain the optimum mesh. These elements were three and six-noded triangular hybrid and four-noded quadrilateral hybrid for modeling of the cortex and nucleus. Constant strain triangular and regular quadrilateral elements were examined for modeling the capsule. One dimensional two degree of freedom spring elements were used to model the anterior, posterior, and equatorial zonules. Five different lens profiles were selected to mathematically model the lens geometry, which included Lizak; Krueger A; Krueger B; Strenk A; and Strenk B. A displacement-based incremental loading history was applied to the equatorial zonule to conduct geometric nonlinear analysis. The converged solution was obtained by coupling Hilbert L-2 norm and equating external work done to internal system strain energy. The converged and optimum solution was compared with analytical solution reported in literature and was selected to conduct a comprehensive parametric study. To study the effect of relative movement, due to zonule traction, between the capsule and the cortex, and cortex and nucleus, contact elements were introduced in the interface between each two regions. A parametric study was conducted to study the effects of force and geometry related variables on the lens's optical power based on the aforementioned lens profiles, including the variation of their central and capsular thicknesses within their physiologically possible range. The position of the zonules was also varied for each profile. The force related variables were stiffness of: capsule; cortex; nucleus and zonules. The complete analysis of the parametric study including the comparison between this study and those reported in the literature is presented. The findings are also compared with physiology of the lens. en_US
dc.description.sponsorship Abolmaali, Ali en_US
dc.language.iso EN en_US
dc.publisher Civil & Environmental Engineering en_US
dc.title Nonlinear Finite Element Model Analysis Of Human Accommodation Lens en_US
dc.type M.S. en_US
dc.contributor.committeeChair Abolmaali, Ali en_US Civil & Environmental Engineering en_US Civil & Environmental Engineering en_US University of Texas at Arlington en_US masters en_US M.S. en_US
dc.identifier.externalLinkDescription Link to Research Profiles

Files in this item

Files Size Format View
umi-uta-1049.pdf 1.172Mb PDF View/Open
1.172Mb PDF View/Open

This item appears in the following Collection(s)

Show simple item record


My Account


About Us