Graduate Studies
Date of this Version
Fall 11-25-2013
Citation
Praveen Akula, "BLAST INDUCED TRAUMATIC BRAIN INJURY: ROLE OF EAR OPENINGS" University of Nebraska-Lincoln, MS thesis, 2013
Abstract
It was well known that ears are the most vulnerable organ to injury subjected to blast loadings. However the impact of ear opening on the traumatic brain injury (TBI), one specific transduction pathway of blast energy to the brain, is not fully understood. The goal of this work is to develop effective computational models to characterize the role of ear openings on TBI. Encouraged by the observations in post-mortem human specimen (PMHS) experiments, we hypothesized that the ear openings aggravate the TBI.
A three dimensional human head with ear opening details was reconstructed from MRI images, and then subjected to simulated blast loadings. The brain responses in terms of intracranial stresses and skull deformations were characterized along three orientations of ear opening related to the incoming blast wave, which were compared with the experimental results from a PMHS head with/without sealed ear canals subjected to a blast overpressure of 0.2 MPa. Simplified head models, i.e., a plane strain cylindrical skull with and without ear opening, were also developed to assess the impact of opening parameters including its geometry and orientation on the brain dynamics.
The peak overpressure was observed in the ear canal when facing the blast wave. This resulted in the severe damage to the ear organs, but seldom altered the brain dynamics in the realistic head modeling. This is contradicting to the experimental observations, which might be explained by the different skull deformations. It also demonstrated that the effect of blast wave alone propagating through ear opening is minimal. It was speculated though that the damages in ear organs could be manifested into cellular level damage in the brain at its associated regions.
Advisor: Linxia Gu
Comments
A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Mechanical Engineering and Applied Mechanics, Under the Supervision of Professor Linxia Gu. Lincoln, Nebraska: November, 2013
Copyright (c) 2013 Praveen Kumar Akula