Citation

Sundaramurthy A, Alai A, Ganpule S, Holmberg A, Plougonven E, Chandra N. J. Neurotrauma 2012; 29(13): 2352-2364.

Affiliation

University of Nebraska Lincoln, Department of Mechanical and Materials Engineering, Lincoln, Nebraska, United States; aravind1403@gmail.com.

Copyright

(Copyright © 2012, Mary Ann Liebert Publishers)

DOI

10.1089/neu.2012.2413

PMID

22620716

Abstract

Blast waves generated by improvised explosive devices (IEDs) cause traumatic brain injury (TBI) in soldiers and civilians. In vivo animal models in conjunction with shock tubes are extensively used in laboratories to simulate field conditions, to identify mechanisms of injury, and to develop injury thresholds. In this paper, we place rats in different placement locations along the length of the shock tube i.e., inside, outside and near the exit, to examine the role of animal placement location (APL) on the biomechanical load experienced by the animal. We found that the biomechanical load on the brain and internal organs in the thoracic cavity (lungs, heart) varied significantly depending on the APL. When the specimen is positioned outside, organs in the thoracic cavity experience a higher pressure for a longer duration, in contrast to APL inside the shock tube. This in turn will possibly alter the injury type, severity and lethality. It is found that the optimal APL occurs where the Friedlander waveform is first formed way inside the shock tube. Once the optimal APL was determined, the effect of the incident blast intensity on the surface and intracranial pressure was measured and analyzed. Noticeably, surface and intracranial pressure scales linearly with the incident peak overpressures, though surface pressures are significantly higher than the other two. Further, we developed and validated an anatomically accurate finite element model of the rat head. With this model, we determined that the main pathway of pressure transmission to the brain was through the skull and not through the snout; however, snout plays a secondary role in diffracting the incoming blast wave towards the skull.

Language: en