Journal article
Identifying Heterogeneous Anisotropic Properties in Cerebral Aneurysms: A Pointwise Approach
Biomechanics and modeling in mechanobiology, Vol.10(2), pp.177-189
04/2011
DOI: 10.1007/s10237-010-0225-7
PMCID: PMC4260822
PMID: 20490886
Abstract
The traditional approaches of estimating heterogeneous properties in a soft tissue structure using optimization based inverse methods often face difficulties because of the large number of unknowns to be simultaneously determined. This article proposes a new method for identifying the heterogeneous anisotropic nonlinear elastic properties in cerebral aneurysms. In this method, the local properties are determined directly from the pointwise stress-strain data, thus avoiding the need for simultaneously optimizing for the property values at all points/regions in the aneurysm. The stress distributions needed for a pointwise identification are computed using an inverse elastostatic method without invoking the material properties in question. This paradigm is tested numerically through simulated inflation tests on an image-based cerebral aneurysm sac. The wall tissue is modeled as an eight-ply laminate whose constitutive behavior is described by an anisotropic hyperelastic strain-energy function containing four parameters. The parameters are assumed to vary continuously in the sac. Deformed configurations generated from forward finite element analysis are taken as input to inversely establish the parameter distributions. The delineated and the assigned distributions are in excellent agreement. A forward verification is conducted by comparing the displacement solutions obtained from the delineated and the assigned material parameters at a different pressure. The deviations in nodal displacements are found to be within 0.2% in most part of the sac. The study highlights some distinct features of the proposed method, and demonstrates the feasibility of organ level identification of the distributive anisotropic nonlinear properties in cerebral aneurysms.
Details
- Title: Subtitle
- Identifying Heterogeneous Anisotropic Properties in Cerebral Aneurysms: A Pointwise Approach
- Creators
- Xuefeng Zhao - Department of Mechanical and Industrial Engineering, Center for Computer Aided Design The University of Iowa, Iowa City, IA 52242-1527, USAMadhavan L Raghavan - Department of Biomedical Engineering, The University of Iowa, Iowa City, IA 52242, USAJia Lu - Department of Mechanical and Industrial Engineering, Center for Computer Aided Design The University of Iowa, Iowa City, IA 52242-1527, USA
- Resource Type
- Journal article
- Publication Details
- Biomechanics and modeling in mechanobiology, Vol.10(2), pp.177-189
- DOI
- 10.1007/s10237-010-0225-7
- PMID
- 20490886
- PMCID
- PMC4260822
- NLM abbreviation
- Biomech Model Mechanobiol
- ISSN
- 1617-7959
- eISSN
- 1617-7940
- Language
- English
- Date published
- 04/2011
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Mechanical Engineering
- Record Identifier
- 9984064207802771
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