Develop an understanding of the biomechanics of dilatational brain injury injury.

Certain types of brain injury have been attributed to the low pressures that develop in the brain and its surrounding cerebrospinal fluid that are thought to produce local cavitation.

Although acceleration caused cavitation can be estimated in a fluid through hydrostatic arguments, the generation of vapor regions, their dynamics, and their effects on the brain tissue where damage is observed are not well understood. The complex mechanical and thermo-dynamical interactions make this problem very difficult to address computationally. Understanding of this phenomenon is needed to aid in the development of brain injury measures that can predict this mode of injury.

Develop state-of-the-art computational fluid dynamics models of the head-brain complex capable of accounting for the motion of the skull and brain and the multiphase flow aspects of the cerebral spinal fluid (CSF). Validate this model against existing head impact data. Develop a physical model of the head, brain, and CSF to allow observation of the cavitation phenomena.

Establishing a biomechanically based understanding of cavitation caused injury will allow the development of an important criterion in head injury that can be scaled to other population groups and to other impact conditions.

Physical model tests will be completed by the second quarter of calendar year 1998. Completion of further work in this project will be date will be based on FY 1999 funding.

• Bandak, F.A. "Impact Traumatic Brain Injuries: A Mechanical Perspective", in Proceeding of the 7th Lubeck Neurotramatology Conference. 1997, In print.
• Bandak, F.A., Eppinger, R.H., and Ommaya, A.K. Traumatic Brain Injury: Bioscience and Mechanics. Mary Ann Libert, New York, 1996.
• Ommaya, A.K., Thibault, L.E., and Bandak, F.A., "Mechanisms of Impact Head Injury", Int. J. Impact Engineering, 15(4), 1994, pp 535-560.
• Bandak, F.A., "On the Mechanics of Impact Neurotrauma: A Review and Critical Synthesis", J. Neurotrauma, 12(4), 1995, pp 635-649.
• Vossoughi, J. and Bandak, F.A., "Mechanical Characteristics of Vascular Tissue and Their Role in Brain Injury Modeling: A Review", in F.A. Bandak, R.H. Eppinger, and A.K. Ommaya (Eds.), Traumatic Brain Injury: Bioscience and Mechanics. Mary Ann Liebert, Inc., 1996, pp 207-215.