颅脑减速碰撞中脑组织空化效应的模拟研究

目的:构建一种新的方法用于再现颅脑减速撞击过程中对冲部位的空化效应.方法:制作含微气泡的透明颅脑物理模型,并将其安放在竖式颅脑减速撞击移动平台上.在高强度灯光的照明环境中,将移动平台以40 cm的高度自由下落而撞击固定台面,同时采用高速摄像记录减速撞击的整个过程.之后用序列图片分析软件计算微气泡的体积与平均压力的变化,研究碰撞过程中脑组织的空化效应.结果:位于撞击对侧的微气泡在撞击过程中其体积明显增大,位于撞击侧的微气泡在撞击过程中其体积减小,位于中性点的微气泡在撞击过程中其体积增减不明显.结论:该实验结果表明颅脑对冲部位出现了负压,存在空化现象.清晰直观地再现了颅脑减速撞击过程中对冲部位的空化效应.有助于在一定程度上较好地认识颅脑减速撞击过程中脑组织内动态应力的分布特点,为阐明交通事故伤中较为常见的颅脑"对冲伤"的力学发生机制提供一定的方法和实验基础.同时该方法对于研究颅脑减速撞击损伤的致伤机理及其诊断和防护具有重要意义.

The Modeling Study of the Cavitation Effect in Brain Tissue during the Brain Deceleration Impact

Purpose: Set up a new technique to reproduce the cavitation effect in the process of brain deceleration impact Methods: A transparent physical brain model with tiny air bubbles was built and loaded on an upright brain deceleration impacting moveable platform. Then, in the high strength lighting circumstance, the moveable platform was made to free fall from a height of 40cm and impacted on a fixed platform, and the whole deceleration impacting process was recorded by a high-speed video camera. Using the serial pictures analysing software, the volume and mean pressure change of the air bubbles were calculated and the cavitation effect of the brain tissue during the impact was studied. Results: The volume of the air bubble in the contrecoup site increased obviously in the impacting process, the volume of the air bubble in the coup site decreased in the impacting process and the volume change of the air bubble in the middle site was not evident enough in the impacting process. Conclusion: The results proved the negative pressure and the cavitation phenomenon in the contrecoup site. The experiments explicitly and directly showed the cavitation effect in the contrecoup site during the decelerating impact It was helpful to better understand the distribution characters of the dynamic stress of the brain tissue in the brain decelerating impact in a certain extent, and it could also provide some methods and experimental foundation to clarify the mechanical mechanism of the brain "contrecoup injury" which was often taken place in traffic accidental injury. Besides, the methods were of significance to research the biomechanism, diagnosis and prevention of the brain deceleration impacting injury.