六岁儿童头部的有限元建模及碰撞仿真分析

发布时间：2018-03-07 11:21

本文选题：损伤生物力学　切入点：CT扫描图像　出处：《天津科技大学》2012年硕士论文　论文类型：学位论文

【摘要】：近年来,颅脑损伤在儿童中经常发生。儿童的脑部正处于发育期,故对损伤较为敏感,即使从外表看伤情不重,但仍可能造成脑组织的损伤而影响智力的发展。因此,对于儿童头部的损伤问题越来越受到科学家的重视。本研究利用儿童头部CT扫描图像,借助图形处理和阈值分割,三维重建和有限元网格划分技术,建立一个具有详细解剖结构的6岁儿童头部的有限元模型。该模型通过尸体实验验证了其有效性。在相同的加载条件下,仿真分析得出的颅内压力分布趋势与尸体实验基本一致。在7900N的输入力下,仿真实验中撞击侧脑组织最大压力值出现在额叶区域为220.2Kpa,对撞侧脑组织最大压力值出现在小脑区域为-135.2Kpa。造成儿童与成人颅内压力不同的因素主要有两方面原因,一是儿童头部的颅骨的弹性模量较成人的值要小且存在骨缝,二是儿童颅骨的厚度要比成人的小。通过对比尸体实验数据,儿童与成人在受到相同的载荷下或相同HIC值下,儿童更容易损伤。研究主要内容如下： 1)根据解剖学知识,分析了儿童与成人头部的主要区别；综述生物力学的一些基本概念以及头部遭到碰撞损伤的特点；综述了成人头部损伤准则和儿童损伤准则的发展； 2)基于CT扫描图片,通过阈值分割提取头部的相关结构,利用逆向工程软件和网格划分软件,构建六岁头部的三维有限元模型； 3)验证模型有效性,并讨论了影响儿童头部颅内压力的主要因素； 4)利用模型模拟了正面碰撞实验和侧面碰撞实验。本研究,构建了一个具有详细解剖结构的6岁儿童头部有限元模型,为后续儿童头部颅内损伤的研究以及儿童防护装置的开发,具有十分重要的价值。
[Abstract]:In recent years, craniocerebral injury has often occurred in children. The brain of children is in the developmental stage, so they are sensitive to the injury. Even if the injury is not serious in appearance, it may still cause brain tissue injury and affect the development of intelligence. More and more attention has been paid to the problem of head injury in children. In this study, CT scan images of children's heads, image processing and threshold segmentation, three-dimensional reconstruction and finite element mesh generation techniques are used. A finite element model of the head of a 6-year-old child with a detailed anatomical structure was established. The model was validated by cadaver experiments. The distribution trend of intracranial pressure obtained by simulation analysis is basically consistent with that of cadaveric experiments. Under the input force of 7900N, In the simulation experiment, the maximum pressure of brain tissue in the impingement side was 220.2 KPA in the frontal lobe and -135.2 Kpa. in the cerebellar region of the impingement side. There are two main reasons for the difference in intracranial pressure between children and adults. One is that the elastic modulus of the skull of the head of the child is smaller than that of the adult, and the other is that the thickness of the skull of the child is smaller than that of the adult. By comparing the cadaveric experimental data, it is found that the child and the adult are under the same load or under the same HIC value. Children are more vulnerable. The main contents of the study are as follows:. 1) according to the anatomical knowledge, the main differences between children and adults are analyzed, some basic concepts of biomechanics and the characteristics of head damage caused by collision are reviewed, and the development of adult head injury criterion and child injury criterion are summarized. 2) based on CT scanning images, the structure of the head is extracted by threshold segmentation, and the three-dimensional finite element model of the six-year-old head is constructed by using reverse engineering software and meshing software. 3) verify the validity of the model and discuss the main factors that affect the intracranial pressure in children. 4) the frontal impact experiment and the side impact experiment are simulated by using the model. In this study, a finite element model of the head of a 6-year-old child with detailed anatomical structure was constructed, which is of great value for the subsequent study of intracranial head injury in children and the development of a protective device for children.
【学位授予单位】：天津科技大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R726.5;U467.14

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