人头部力锤冲击试验的生物力学研究

Biomechanical study on the impact tests conducted on human head with hammer

目的:探讨人头部受主动冲击的钝力作用时的力响应特点,同时测试头部各部位承受最大冲击力的限度,从冲击动力学角度去探讨颅脑损伤的生物力学机理。方法:使用配备大量程力传感器的力锤对人尸体头部各部位进行冲击试验,记录接触力响应曲线,并手工记录锤头的质地、质量、初速度、冲击面大小,以及被冲击的头部是否有破坏性反应(头皮挫裂及颅骨骨折)。结果:人头部对主动冲击的钝物的接触力响应曲线为类似正弦波的脉冲波形,其波形宽度及峰值因冲击物的质地、有无头皮等发生变化;人头部在小面积钝物的冲击作用下,造成头皮挫裂的冲击力最大值平均为5100N;使颞部、顶部、额部、枕部骨折的冲击力最大值的平均值分别为6200、8100、8300、11000N;利用试验得到的数据,验证了作用于头部的钝物与头部组成的系统相当于带有强阻尼的弹簧振子。结论:头部在受到主动冲击时,典型的接触力-时间曲线为类似正弦波的脉冲波形;大面积的钝器作用于头部造成的颅骨骨折,更多发生延伸至远处的线形骨折;本试验还得出了人头部能耐受的冲击力大小等参数,这些对于建立有限元模型进行分析和验证是必须的。

Objective: To study the dynamic characteristics of human head impacted with hammer and measure the value of endurable maximum force underwent by each part of human head. Methods: The hammer equipped with a force sensor in its anterior part was used to demonstrate the dynamical characteristics of human head. The response curve was recorded on the screen of a storable oscillometer in different cases. The laceration of scalp and the fracture of skull were recorded. Results: The typical contact force-time curve was obtained .The approximate values of endurable maximum force in tempus, parietalis, frons and occiput respectively were 6200N, 8100N, 8300N, and 11,000N. The system consisted of the hammer and human head during contact time can be considered as a damped oscillator. Conclusions: The contact force-time curve is similar to sine wave pulse and its start part and end part have 'fillet-like' changes. The skull fractures resulted from the impact by the hammer with large area are chiefly linear fracture other than depressed fracture.