家兔肝脏冲击损伤及其力学参数的研究

肝脏是人体的重要器官,在汽车碰撞、飞机坠毁以及飞船着陆等冲击环境中,肝脏是最易受冲击而损伤的内脏器官之一,当肝脏损伤严重时,人体会由于失血过多而死亡。本文通过对家兔肝脏的冲击损伤的研究,了解肝脏对各种冲击条件的力学响应以及受冲击致伤的不同机理,找到评价肝脏损伤的合适的力学参数,为研究肝脏冲击损伤的力学模型以及研制冲击防护系统打下基础。实验共采用了44只家兔,将其麻醉后手术暴露肝脏,直接对肝脏进行冲击,实验中测量冲击加速度和冲击力,并在实验后用计算机计算得出其它的力学参数。在冲击实验结束后,立即对肝脏损伤的程度进行观察并定级。通过对以上实验得到的力学参数和肝脏损伤级别的分析,本文认为:在冲击头的质量不变时,肝脏损伤程度与冲击初速度成正比。以相等的冲击能量或相等的冲击动量冲击肝脏并不能造成相等的损伤程度。肝脏损伤的程度与其自身的力学响应有关。在评价损伤时,应综合考虑最大压缩量、最大冲击力、最大粘性响应和平均功率力学指标,同时应注意各力学指标的适用的冲击条件。本实验提出的平均功率Q 能反映肝脏受冲击面的损伤程度,可为全面评价肝损伤而建立新的力学指标。

A Study of Rabbit's Liver Impact Injury and its Mechanical Parameters

44 rabbits were used in this experiment.The rabbits' liver were exposedby surgical operation and impacted directly by an impact bar.Impact acceleration,impactforce and the injury level of the liver were observed.The results demonstrated that liver is aviscoelastic material,its injury was related to stress,strain and rate of strain;when liver in-jury was evaluated,maximum impact displacement,maximum impact force,maximum vis-cous response and the average impact power must be considered comprehensively.The ap-propriate use of the parameters in different impact conditions was important;in dynamic im-pact condition,average impact power can reflect the injury level in the liver's diaphragmaticsurface very well.It is a new parameter which can help us in evaluating liver injury com-prehensively.