University of Cincinnati James L. Winkle College of Pharmacy, Division of Pharmaceutical Sciences, Cincinnati, OH, United States of America.
University of Cincinnati College of Arts and Sciences, Department of Biological Sciences, Cincinnati, OH, United States of America.
Biomed Phys Eng Express. 2022 Nov 4;8(6). doi: 10.1088/2057-1976/ac9abc.
With the evolution of modern warfare and the increased use of improvised explosive devices (IEDs), there has been an increase in blast-induced traumatic brain injuries (bTBI) among military personnel and civilians. The increased prevalence of bTBI necessitates bTBI models that result in a properly scaled injury for the model organism being used. The primary laboratory model for bTBI is the shock tube, wherein a compressed gas ruptures a thin membrane, generating a shockwave. To generate a shock wave that is properly scaled from human to rodent subjects many pre-clinical models strive for a short duration and high peak overpressure while fitting a Friedlander waveform, the ideal representation of a blast wave. A large variety of factors have been experimentally characterized in attempts to create an ideal waveform, however we found current research on the gas composition being used to drive shock wave formation to be lacking. To better understand the effect the driver gas has on the waveform being produced, we utilized a previously established murine shock tube bTBI model in conjunction with several distinct driver gasses. In agreement with previous findings, helium produced a shock wave most closely fitting the Friedlander waveform in contrast to the plateau-like waveforms produced by some other gases. The peak static pressure at the exit of the shock tube and total pressure 5 cm from the exit have a strong negative correlation with the density of the gas being used: helium the least dense gas used produces the highest peak overpressure. Density of the driver gas also exerts a strong positive effect on the duration of the shock wave, with helium producing the shortest duration wave. Due to its ability to produce a Friedlander waveform and produce a waveform following proper injury scaling guidelines, helium is an ideal gas for use in shock tube models for bTBI.
随着现代战争的演变和简易爆炸装置（IED）使用的增加，军事人员和平民中的爆炸伤性脑损伤（bTBI）有所增加。bTBI 的发病率增加需要 bTBI 模型，这些模型为所使用的模型生物产生适当比例的损伤。bTBI 的主要实验室模型是激波管，其中压缩气体破裂薄膜，产生冲击波。为了生成与人体到啮齿动物主体适当比例的冲击波，许多临床前模型都力求在满足弗莱德兰德波形的情况下，具有较短的持续时间和较高的峰值超压，这是冲击波的理想表示。为了创建理想的波形，已经对各种因素进行了实验表征，但是我们发现，当前有关用于驱动冲击波形成的气体组成的研究还不够。为了更好地了解驱动气体对产生的波形的影响，我们利用了先前建立的鼠类激波管 bTBI 模型，并结合了几种不同的驱动气体。与先前的发现一致，氦气产生的冲击波最接近符合弗莱德兰德波形，而其他一些气体产生的则是类似平台的波形。激波管出口处的峰值静态压力和距出口 5 厘米处的总压力与所用气体的密度呈很强的负相关：所用的密度最低的氦气产生的峰值超压最高。驱动气体的密度也对冲击波的持续时间产生强烈的正向影响，氦气产生的持续时间最短。由于其能够产生弗莱德兰德波形并产生符合适当损伤比例准则的波形，因此氦气是用于 bTBI 激波管模型的理想气体。
