含气组织器官对冲击波负压的动态响应──高速摄影研究

DYNAMIC RESPONSE OF GAS CONTAINED ORGANS TO UNDERPRESSURE OF BLAST WAVE A HIGH SPEED PHOTOGRAPHIC STUDY

本实验采用冲击波负压发生装置模拟单纯冲击波负压，观察大鼠、离体肺、含气鱼泡对冲击波负压的动态响应。高速摄影法研究结果表明，在冲击波负压作用下，离体肺的扩张幅度、速度和加速度比大鼠胸部相应的扩张幅度、速度和加速度大，鱼泡膨胀扩张明显，并在扩张期破裂，提示肺泡在冲击波负压作用下出现扩张性损伤。因此，本实验结果支持以下假说，即在冲击波负压作用下，胸壁扩张后，肺组织迅速扩张，在某一时刻，肺组织扩张速度大于胸壁扩张速度，两者运动存在着不同步状态，肺组织主动撞击胸壁，引起肺表面出血。冲击波负压发生机理的研究有助于对冲击波致伤机理的认识。

The gas contained organs, such as the rat, the isolated lungs and a fish bladder, were exposed to the underpressure of the blast wave simulated by an underpressure generator. A high speed photography was used to observe the dynamic response of the rat, the isolated lungs and the fish bladder to the underpressure, of which the peak level, the decreasing time and the duration were -60kPa, 3ms and 70ms, respectively. The experimental results showed that the maximal displacement, the maximal velocity and acceleration of the expansion in the isolated lungs were respectively greater than those in the chest wall of the rat, and the fish bladder expanded to an extent that it ruptured so rapidly. All these indicated that the alveoli, exposing to the underpressure, would be damaged in the phase of its expansion and testified the hypothesis: After exposure to the underpressure, the chest wall expanded first and sucked the lungs which then moved outward so rapidly that it impacted on the chest wall due to the suction of the underpressure and the higher compliance of the lungs. The impact of the lungs on the chest wall would induce the hemorrhage on the lung surface, such as the hemorrhagic stripes. This hypothesis explaining the underpressure inflicting injury on the lungs contributed to a certain extent to the realization of the mechanisms of the lung blast in juries.