Research and Exploratory Development Department, Johns Hopkins University Applied Physics Laboratory, Laurel, MD, United States of America.
PLoS One. 2024 May 15;19(5):e0303325. doi: 10.1371/journal.pone.0303325. eCollection 2024.
Since the 19th century, underwater explosions have posed a significant threat to service members. While there have been attempts to establish injury criteria for the most vulnerable organs, namely the lungs, existing criteria are highly variable due to insufficient human data and the corresponding inability to understand the underlying injury mechanisms. This study presents an experimental characterization of isolated human lung dynamics during simulated exposure to underwater shock waves. We found that the large acoustic impedance at the surface of the lung severely attenuated transmission of the shock wave into the lungs. However, the shock wave initiated large bulk pressure-volume cycles that are distinct from the response of the solid organs under similar loading. These pressure-volume cycles are due to compression of the contained gas, which we modeled with the Rayleigh-Plesset equation. The extent of these lung dynamics was dependent on physical confinement, which in real underwater blast conditions is influenced by factors such as rib cage properties and donned equipment. Findings demonstrate a potential causal mechanism for implosion injuries, which has significant implications for the understanding of primary blast lung injury due to underwater blast exposures.
自 19 世纪以来，水下爆炸一直对军人构成重大威胁。虽然已经有尝试为最脆弱的器官（即肺部）建立损伤标准，但由于缺乏人体数据，相应地无法了解潜在的损伤机制，现有的标准存在很大差异。本研究对模拟水下冲击波暴露时孤立人肺的动力学进行了实验表征。我们发现，肺表面的大声阻抗严重衰减了冲击波传入肺部的强度。然而，冲击波引发了大容量压力-体积循环，与类似加载下固体器官的响应明显不同。这些压力-体积循环是由于所含气体的压缩引起的，我们用瑞利-普莱塞特方程对其进行了建模。这些肺动力学的程度取决于物理约束，而在实际水下爆炸条件下，肋骨结构和佩戴的设备等因素会影响物理约束。研究结果表明了内爆损伤的潜在因果机制，这对理解水下爆炸引起的原发性爆震性肺损伤具有重要意义。
