高速小口径步枪弹致防弹衣后猪背部钝性损伤特点

Features of blunt wound in back of pig wearing composite armour hit by high speed microstomia Rifle bullet

目的研究某型高速小口径步枪弹(简称某步枪弹)致复合防弹衣保护下的长白猪背部钝性损伤的特点及力学机制。方法 17头长白猪随机数字表法分为实验组(n=9)、对照组(n=5)和压力测定组(n=3)。实验组采用复合防弹衣(陶瓷防弹板+超高分子量聚乙烯)防护猪背部,以某步枪弹瞄准背部T8椎体射击防弹衣,观察射击前、后猪心率、动脉血压和血氧饱和度,检测脑电、心电;射击后6 h活杀解剖,观察猪病理损伤特点。对照组除射击无弹头的等量弹药的空包弹外,余处理同实验组。压力测定组仅测定某步枪弹射击猪背部时局部压力。结果实验组、压力测定组防弹衣均未击穿,步枪弹命中防弹衣瞬间,防弹衣后局部肌肉组织压力升高明显,猪心率、动脉收缩压、心电与对照组相比无明显变化,防弹衣后脊髓呈钝挫伤病理改变,心内膜、肺脏、肝脏、肾、脾脏轻度出血。结论某型高速小口径步枪弹击中猪背部复合防弹衣时,防弹衣虽未击穿,但防弹衣后脊髓及胸腹腔脏器组织存在不同程度钝性损伤,这可能与防弹衣快速变形造成的背部钝性撞击,局部压力升高有关。

Objective To investigate the features of back wounds and mechanical mechanism of experimental pigs protected by composite armour hit by high speed microstomia Rifle bullet. Methods A total of 17 pigs were randomly divided into experimental group （n = 9 ）, control group （n = 5 ） and pressure testing group （ n = 3 ）. Pigs of the experimental group adopt composite armour （ ceramic bulletproof plates ＋ ultra-high molecular weight polyethylene） to protect their back and get shoot by high speed microstomia Rifle bullets aim at I＇8 back centrum vertebrae. Control group received same procedures as experimental group except shooting e- quivalence cartridge without bullet. Pressure test group was used to measure local timely pressure shooting by Rifle bullet. The pigs were observed for heart rate （HR）, systolic arterial pressure （SAP）, and electrocardio- graphy and electroencephalography were performed. In 6 h after shooting, the pigs of the experiment and control groups were sacrificed for pathological observation. Results Composite armour was not broken in the experi- mental and pressure test groups. Local muscle tissue received obviously increased pressure at the shooting time. No obvious change was found in HR, SAP, and electrocardiogram between the experimental and control groups. Significant blunt injury was seen in the spinal cord covered by armour. Mild bleeding was found in the endocar- dium, lung, liver, kidneys, and spleen. Conclusion When high speed microstomia Rifle bullet shoots pig back with composite armour, the spinal cord, cavitas thoracis, and peritoneal cavity tissues have blunt injuries with different severities though the armour was not disrupted. This may be due to back passive state impact caused by the armour distorted quickly and increase of local pressure.