Kote Vivek Bhaskar, Frazer Lance L, Hostetler Zachary S, Jones Derek A, Davis Matthew, Op't Eynde Joost, Kait Jason, Pang Derek, Bass Dale, Koser Jared, Shah Alok, Yoganandan Narayan, Stemper Brian, Bentley Timothy, Nicolella Daniel P
Southwest Research Institute, San Antonio, TX, USA.
Elemance, LLC, Winston-Salem, NC, USA.
Ann Biomed Eng. 2024 Jun 26. doi: 10.1007/s10439-024-03564-3.
Evaluating Behind Armor Blunt Trauma (BABT) is a critical step in preventing non-penetrating injuries in military personnel, which can result from the transfer of kinetic energy from projectiles impacting body armor. While the current NIJ Standard-0101.06 standard focuses on preventing excessive armor backface deformation, this standard does not account for the variability in impact location, thorax organ and tissue material properties, and injury thresholds in order to assess potential injury. To address this gap, Finite Element (FE) human body models (HBMs) have been employed to investigate variability in BABT impact conditions by recreating specific cases from survivor databases and generating injury risk curves. However, these deterministic analyses predominantly use models representing the 50th percentile male and do not investigate the uncertainty and variability inherent within the system, thus limiting the generalizability of investigating injury risk over a diverse military population. The DoD-funded I-PREDICT Future Naval Capability (FNC) introduces a probabilistic HBM, which considers uncertainty and variability in tissue material and failure properties, anthropometry, and external loading conditions. This study utilizes the I-PREDICT HBM for BABT simulations for three thoracic impact locations-liver, heart, and lower abdomen. A probabilistic analysis of tissue-level strains resulting from a BABT event is used to determine the probability of achieving a Military Combat Incapacitation Scale (MCIS) for organ-level injuries and the New Injury Severity Score (NISS) is employed for whole-body injury risk evaluations. Organ-level MCIS metrics show that impact at the heart can cause severe injuries to the heart and spleen, whereas impact to the liver can cause rib fractures and major lacerations in the liver. Impact at the lower abdomen can cause lacerations in the spleen. Simulation results indicate that, under current protection standards, the whole-body risk of injury varies between 6 and 98% based on impact location, with the impact at the heart being the most severe, followed by impact at the liver and the lower abdomen. These results suggest that the current body armor protection standards might result in severe injuries in specific locations, but no injuries in others.
评估防弹衣后钝性创伤（BABT）是预防军事人员非穿透性损伤的关键步骤，这种损伤可能由射弹撞击防弹衣时动能的传递导致。虽然当前的美国国家司法研究所（NIJ）标准0101.06侧重于防止防弹衣背面过度变形，但该标准并未考虑撞击位置、胸部器官和组织材料特性以及损伤阈值的变异性，以便评估潜在损伤。为了弥补这一差距，有限元（FE）人体模型（HBM）已被用于通过从幸存者数据库中重现特定案例并生成损伤风险曲线来研究BABT撞击条件的变异性。然而，这些确定性分析主要使用代表第50百分位男性的模型，并未研究系统固有的不确定性和变异性，从而限制了在不同军事人群中研究损伤风险的普遍性。由美国国防部资助的I-PREDICT未来海军能力（FNC）引入了一种概率性HBM，该模型考虑了组织材料和失效特性、人体测量学以及外部加载条件的不确定性和变异性。本研究利用I-PREDICT HBM对三个胸部撞击位置——肝脏、心脏和下腹部进行BABT模拟。对BABT事件导致的组织水平应变进行概率分析，以确定器官水平损伤达到军事战斗失能量表（MCIS）的概率，并使用新损伤严重度评分（NISS）进行全身损伤风险评估。器官水平的MCIS指标表明，心脏部位的撞击会导致心脏和脾脏严重损伤，而肝脏部位的撞击会导致肋骨骨折和肝脏严重撕裂伤。下腹部的撞击会导致脾脏撕裂伤。模拟结果表明，在当前的防护标准下，根据撞击位置的不同，全身受伤风险在6%至98%之间变化，心脏部位的撞击最为严重，其次是肝脏部位和下腹部的撞击。这些结果表明，当前的防弹衣防护标准可能会在特定位置导致严重损伤，而在其他位置则不会造成损伤。
