不同振动载荷刺激对L1-L5腰椎的生物力学响应研究

Biomechanical Study of Lumbar Spine Under Different Vibration Conditions

通过有限元力学分析不同条件振动载荷刺激下腰椎的力学响应情况,进而确定振动参数对腰椎的生物力学影响。本文基于CT扫描图像,运用Mimics对腰椎L1-L5节段进行三维重建,利用Geomagic Studio进行曲面构型,运用Hypermesh和Abaqus建立有限元模型,并在Abaqus中计算不同振动频率和振幅下的腰椎松质骨部位的应力矢量/张量变化。结果显示在一个振动周期内,椎体骨主要受拉应力。椎体应力分布均匀,上下表面应力较大,上表面左后侧出现应力集中现象。不同频率与振幅条件下的振动,椎体所受应力分布情况相似,频率的变化对应力大小无明显影响,而振幅越大应力越大。结果表明频率和振幅参数对椎体的应力分布影响较小,振幅与应力大小成正相关。然而,骨形成具有长时间积累效应,需要进一步探究长时间疲劳影响。

We observed the effect of vibration parameters on lumbar spine under different vibration conditions using finite element analysis method in our laboratory.In this study,the CT-images of L1-L5 segments were obtained.All images were used to develop 3Dgeometrical model using the Mimics10.01（Materialise,Belgium）.Then it was modified using Geomagic Studio12.0（Raindrop Geomagic Inc.USA）.Finite element（FE）mesh model was generated by Hypermesh11.0（Altair Engineering,Inc.USA）and Abaqus.Abaqus was used to calculate the stress distribution of L1-L5 under different vibration conditions.It was found that in a vibration cycle,tensile stress was occurred on lumbar vertebra mainly.Stress distributed evenly and stress concentration occurred on the left rear side of the upper endplate.The stress had no obvious changes under different frequencies,but the stress was higher when amplitude was greater.In conclusion,frequency and amplitude parameters have little effect on the stress distribution in vertebra.The stress magnitude is positively correlated with the amplitude.