三维有限元法分析脊柱保护器对人体胸腰段的支持与保护作用

背景：人体脊柱保护器对预防人体胸腰段脊柱损伤有保护作用，新型动力性保护器的研发需要通过多种实验手段的验证。 目的：利用三维有限元法分析脊柱保护器在轴向载荷作用下对人体脊柱胸腰段的生物力学响应。 方法：从已建立的全脊柱三维有限元模型中截取胸腰段，将佩戴脊柱保护器的胸腰段模型设计为实验组，未佩戴脊柱保护器的胸腰段模型设计为对照组。给上述两组模型进行赋值、约束、加载、运算，获得目标单元的等效应力及应变。 结果与结论：在垂直承载的两组胸腰段模型中，应力均集中于L2椎体的中、后柱。根据目标单元采集数据发现，实验组与对照组模型在16 ms时达到等效应力最大值，分别为3.919，5.727 MPa。统计分析得出T12与L2节段实验组与对照组等效应力比较，P 均〈0.05，对照组所受应力均大于实验组，差异有显著性意义；而T11与L1节段实验组与对照组的等效应力比较，差异无显著性意义（P〉0.05）。提示脊柱保护器可以明显减少垂直坠地时胸腰段椎体所受的应力，分担载荷，对胸腰段椎体具有保护支持作用。

Three-dimensional finite element analysis on the support and protection of spine protector for thoracic-lumbar vertebra

BACKGROUND：Human spine protector can protect human thoracic-lumbar vertebra segments against injury, and the design and development of a novel dynamic protector needs the verification of various experimental means.
OBJECTIVE：Using the three-dimensional finite element method, we evaluate the effect of spine protector and the biomechanical reaction of thoracic-lumbar vertebra under the axial loading.
METHODThe thoracic-lumbar vertebra were cut from the whole spine three-dimensional finite element model. Then the thoracic-lumbar vertebra models carrying spine protector were taken as experimental group, while the models without the protector served as control group. Al the specimens were evaluated, constrained, loaded and figured out by its properties. The results of equivalent stress and strain distribution were obtained from the data. RESULTS AND CONCLUSION：In both groups, the stress was distributed at axial and posterior column of L 2 when the load was applied in axial direction. According to the data obtained from the experiment, both the experimental group and the control group had achieved the maximum stress at 16 ms, 3.919 Mpa and 5.727 Mpa, respectively. The statistical analysis result showed that the stress varied significantly at T 12 and L 2 in two groups （both P〈0.05）. However, the stress distribution at T 11 and L 1 showed no significant difference between the two groups （both P〉0.05）. Experimental findings indicate that, spine protector can significantly reduce the vertical stress of the thoracic-lumbar vertebra when fal ing on the ground, and share the vertical load, which is protective to thoracic-lumbar vertebra.