Characterizing Blast Waveforms for Traumatic Brain Injury

Abstract

By Mei-Ling Liber, Biological Sciences; Evan Reeder, Pharmaceutical Science

Advisor: Matthew Robson

Awards: Project Advisor Award: Excellence in Research Mentoring

Presentation ID: 203

Abstract: The increased prevalence of improvised explosive device (IED) encounters in Iraq and Afghanistan has greatly increased the number of blast-induced traumatic brain injuries (bTBI) among military personnel. Reliable models of TBI are critical to understanding the underlying molecular mechanisms of acute and long-term comorbidities associated with bTBI. Compressed gas-driven shock tubes have been used by laboratories as a common approach to replicate explosive blast waves to model bTBI in animal subjects. Blast waves scaled for animals should expose subjects to the highest possible peak pressure while minimizing the blast duration. The effects of driver gas selection on the resulting blast-waves have not been well characterized, although previous research has shown that the driver gas has strong influence on the blast wave parameters: magnitude (peak overpressure), duration (positive phase duration), and shape. To demonstrate this, we utilized a murine model of bTBI in conjunction with a variety of driver gases: helium, ambient air, carbon dioxide, argon, and nitrogen. We hypothesized that helium, due its low molecular weight, would produce the closest pressure time profile to the desired blast wave shape. Driver gas molecular weight was a strong predictor of mean peak overpressure (R2 = 0.98) and mean positive phase duration (R2 = 0.91), where helium had the highest mean peak overpressure (1162.16 kPa) and the shortest mean positive phase duration (1.03 ms) compared to other gases. In conclusion, we recommend using helium to produce scaled blast waves that can be used as reliable models for blast-induced TBI in military-affiliated populations.