| dc.description.abstract | Impact induced injury to the human head is a major cause of death and disability; this has
driven considerable research in this field. Despite this, the methods by which the brain is
damaged following non-penetrative (blunt) impact, where the skull remains intact, are not
well understood. The mechanisms which give rise to brain trauma as a result of blunt head
impact are frequently explored using indirect methods, such as finite element simulation.
Finite element models are often created manually, but the complex anatomy of the head
and its internal structures makes the manual creation of a model with a high level of
geometric accuracy intractable. Generally, approximate models are created, thereby
introducing large simplifications and user subjectivity.
Previous work purports that blunt head impacts of short duration give rise to large
dynamic transients of both positive and negative pressure in the brain. Here, three finite
element models of the human head, of increasing biofidelity, were employed to investigate
this phenomenon. A novel approach to generating finite element models of arbitrary
complexity directly from three-dimensional image data was exploited in the development of
these models, and eventually a highly realistic model of the whole head and neck was
constructed and validated against a widely used experimental benchmark.
The head models were subjected to a variety of simulated impacts, ranging from
comparatively long duration to very short duration collisions. The dynamic intracranial
pressure response, characterised by large transients of both positive and negative pressure
in the brain, was observed following short duration impacts in all three of the models used
in this study. The dynamic intracranial response was also recorded following short duration
impacts of high energy, involving large impact forces, which were deemed to be realistic
representations of actual impact scenarios. With the aid of an approximate analytical
solution, analysis of the simulations revealed that the dynamic response is caused by
localised skull deflection, which induces flexural waves in the skull. The implications of
these magnified pressures are discussed, with particular regard to the potential for
intracranial cavitation. | en_GB |
