title: A meta-model analysis of a finite element simulation for defining poroelastic properties of intervertebral discs.
abstract: Finite element analysis is an effective tool to evaluate the material properties of living tissue. For an interactive optimization procedure, the finite element analysis usually needs many simulations to reach a reasonable solution. The meta-model analysis of finite element simulation can be used to reduce the computation of a structure with complex geometry or a material with composite constitutive equations. The intervertebral disc is a complex, heterogeneous, and hydrated porous structure. A poroelastic finite element model can be used to observe the fluid transferring, pressure deviation, and other properties within the disc. Defining reasonable poroelastic material properties of the anulus fibrosus and nucleus pulposus is critical for the quality of the simulation. We developed a material property updating protocol, which is basically a fitting algorithm consisted of finite element simulations and a quadratic response surface regression. This protocol was used to find the material properties, such as the hydraulic permeability, elastic modulus, and Poisson's ratio, of intact and degenerated porcine discs. The results showed that the in vitro disc experimental deformations were well fitted with limited finite element simulations and a quadratic response surface regression. The comparison of material properties of intact and degenerated discs showed that the hydraulic permeability significantly decreased but Poisson's ratio significantly increased for the degenerated discs. This study shows that the developed protocol is efficient and effective in defining material properties of a complex structure such as the intervertebral disc.
authors: School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran.
authors: Mohammad
authors: M
authors: Nikkhoo
authors: Yu-Chun
authors: YC
authors: Hsu
authors: Mohammad
authors: M
authors: Haghpanahi
authors: Mohamad
authors: M
authors: Parnianpour
authors: Jaw-Lin
authors: JL
authors: Wang
mesh_terms: D000818:Animals; D001826:Body Fluids / Q000378:metabolism*; D019245:Compressive Strength; D003198:Computer Simulation; D055119:Elastic Modulus; D020342:Finite Element Analysis; D006801:Humans; D066298:In Vitro Techniques; D007403:Intervertebral Disc / Q000503:physiopathology*; D055959:Intervertebral Disc Degeneration / Q000503:physiopathology*; D008954:Models, Biological; D010539:Permeability; D016062:Porosity; D013314:Stress, Mechanical; D013552:Swine; D013718:Tensile Strength; D016474:Weight-Bearing
keywords: Intervertebral disc; degeneration model; finite element modeling; poroelastic properties; response surface methodology