title: A transversely isotropic constitutive model of excised guinea pig spinal cord white matter.
abstract: Narrowing of the spinal canal generates an amalgamation of stresses within the spinal cord parenchyma. The tissue's stress state cannot be quantified experimentally; it must be described using computational methods, such as finite element analysis. The objective of this research was to propose a compressible, transversely isotropic constitutive model, an augmentation of the isotropic Mooney-Rivlin hyperelastic strain energy function, to describe the guinea pig spinal cord white matter. Model parameters were derived from a combination of inverse finite element analysis on transverse compression experiments and least squared error analysis applied to quasi-static longitudinal tensile tests. A comparison of the residual errors between the predicted response and the experimental measurements indicated that the transversely isotropic constitutive law that incorporates an offset stretch reduced the error by a factor of four when compared to other commonly used models.
authors.affiliation: School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Beth
authors.initials: B
authors.lastname: Galle
authors.forename: Hui
authors.initials: H
authors.lastname: Ouyang
authors.forename: Riyi
authors.initials: R
authors.lastname: Shi
authors.forename: Eric
authors.initials: E
authors.lastname: Nauman
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D019245:Compressive Strength; D004548:Elasticity; D020342:Finite Element Analysis; D006168:Guinea Pigs; D066298:In Vitro Techniques; D016018:Least-Squares Analysis; D023421:Models, Animal; D008959:Models, Neurological; D013116:Spinal Cord / Q000033:anatomy & histology / Q000502:physiology*; D013119:Spinal Cord Injuries / Q000503:physiopathology; D013314:Stress, Mechanical; D013718:Tensile Strength