Analysis of Head Impact

Notable Features of Model

• Multiple structures meshed simultaneously: scalp, skull, brain (white and grey matter), ...
• Contact surfaces generated automatically at interfaces between structures

MRI scan of head

Model of head

Impact simulation

Procedure

A high resolution MRI scan of the head of an adult male was used to generate FE simulations of the response of the human head to blunt impact. The scan was taken axially from the top of the head to the base of the skull with an in-plane coronal slice resolution of 0.9375 mm x 0.9375 mm and slice to slice separation of 1.5mm. The original 3D data set was re-sampled to obtain a 1.5mm x 1.5mm x 1.5mm cubic volume dataset and both manual and semi-automated segmentation was performed using ScanIP to segment out the skull. A 3D FE mesh of the skull, intracranial contents and interface contact surfaces, was generated automatically meshed in ⁺ScanFE.

• FE Mesh Generation
  • Smooth mesh of segmented structures
  • Surface between brain and skull
  • Time to mesh: 1 minute

The same scan data was also used to create a rapid prototyped, life size model of the skull in order to establish experimental corroboration of the FE predictions. Both numerical and physical models were used to measure global response characteristics such as the duration of impact, the peak force transmitted to the skull and the peak pressure received under the site of impact.

• LS-Dyna 3D
  • Ball introduced into model; Impact simulated
  • Solution Time (Intel 2.8 GHz): 40 minutes
  • Number of Degrees of Freedom: 168,200

Publication

Johnson, E.A.C., Young, P.G., 2005. On the use of a patient-specific rapid-prototyped model to simulate the response of the human head to impact and comparison with analytical and finite element models. Journal of Biomechanics, 38, 39-45. Download abstract