The authors of this paper seek to determine the influence of brain mechanical properties on inertial pediatric brain injury. Large deformation material properties of porcine pediatric and adult brain tissue were measured and represented by a first order Ogden hyperelastic viscoelastic constitutive model. A three-dimensional (3-D) finite element (FE) mesh was created of a mid-coronal slice of the brain and skull of a human adult and child (2 weeks old). Three finite element models (FEM's ) were constructed: (1) a pediatric mesh with pediatric brain properties; (2) a pediatric mesh with adult tissue properties; and (3) an adult mesh with adult tissue properties. A fourth simulation was analyzed using the adult mesh and adult material properties with a reduced load as proposed by A. Ommaya et al (1967). Peak maximum principal logarithmic strains (LEP3) were determined in each of the simulations. Overall, brain size and material properties both affected the intracranial tissue deformation field, with brain size having the greater influence. On average, strains in pediatric and adult models produced by loads scaled using the relationship of A. Ommaya et al (1967) were similar, when material properties were assumed to remain constant. When experimentally obtained material properties of adult and pediatric brain tissue were used in the simulations, the scaled loads produced larger strains in the adult model than in the pediatric model.
Abstract