Abstract
Recent studies have shown an increase in the frequency of traumatic brain injuries related to blast exposure. However, the mechanisms that cause blast neurotrauma are unknown. Blast neurotrauma research using computational models has been one method to elucidate that response of the brain in blast, and to identify possible mechanical correlates of injury. However, model validation against experimental data is required to ensure that the model output is representative of in vivo biomechanical response. This study exposes porcine subjects to primary blast overpressures generated using a compressed-gas shock tube. Shock tube blasts were directed to the unprotected head of each animal while the lungs and thorax were protected using ballistic protective vests similar to those employed in theater. The test conditions ranged from 110 to 740 kPa peak incident overpressure with scaled durations from 1.3 to 6.9 ms and correspond approximately with a 50% injury risk for brain bleeding and apnea in a ferret model scaled to porcine exposure. Instrumentation was placed on the porcine head to measure bulk acceleration, pressure at the surface of the head, and pressure inside the cranial cavity. Immediately after the blast, 5 of the 20 animals tested were apneic. Three subjects recovered without intervention within 30 s and the remaining two recovered within 8 min following respiratory assistance and administration of the respiratory stimulant doxapram. Gross examination of the brain revealed no indication of bleeding. Intracranial pressures ranged from 80 to 390 kPa as a result of the blast and were notably lower than the shock tube reflected pressures of 300–2830 kPa, indicating pressure attenuation by the skull up to a factor of 8.4. Peak head accelerations were measured from 385 to 3845 G’s and were well correlated with peak incident overpressure (R2 = 0.90). One SD corridors for the surface pressure, intracranial pressure (ICP), and head acceleration are presented to provide experimental data for computer model validation.
Highlights
Exposure to blasts from explosive devices in the ongoing conflicts in Iraq and Afghanistan has become the most common cause of injury to American soldiers (Okie, 2005; Warden et al, 2005)
Traditional blast injury research has focused on injuries to the air-filled organs, such as the pulmonary system, ear, and gastrointestinal tract, as these have been found to be most susceptible to primary blast overpressure (Bowen et al, 1968; Bass et al, 2008)
The goal of this study is to evaluate the mechanical head response of a large animal with similar body mass to a human when subjected to primary blast waves
Summary
Exposure to blasts from explosive devices in the ongoing conflicts in Iraq and Afghanistan has become the most common cause of injury to American soldiers (Okie, 2005; Warden et al, 2005). Recent studies have shown a decrease in the frequency of tympanic membrane and pulmonary injury due to primary blast despite the higher incidence of blast exposure (Ritenour and Baskin, 2008). There has been an increase in traumatic brain injury attributed to blast exposure (Kennedy et al, 2007). This shift in injury location is likely due to the extensive use of personal protective equipment including ballistic protective vests (Cooper, 1996). Ballistic protective vests are known to attenuate blast overpressure seen by the thorax, decreasing pulmonary injury risk below that of the head (Wood et al, 2012)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
