人类腰段脊柱三维有限元模型的建立

Experiment study of biomechanics on a new three-dimension finite elemen tmodel of the whole lumbar vertebral column

目的为研究人类腰段脊柱生物力学,提供三维有限元含肌肉整体力学模型。方法通过对尸体腰段脊柱表面各节点的三维坐标值测量,运用超级空间有限元电算程序(SUPER-SAPⅤ)将腰段脊柱按空间有限离散的原则,在计算器上建立三维空间坐标系,仿真完整脊柱腰段力学模型。运用横截面积肌力计算法,测量尸体腰椎周围肌肉:腰大肌、腰方肌、竖脊肌、腹内外斜肌、腹横肌的解剖横断面积及其与腰段脊柱纵轴的中心数据值,求得力矩值。再根据力矩等价换算公式得出加载于模型体表各点的肌力值。通过对本模型重力及肌力的加载,使其更接近于正常人体腰段力学状态。结果建立L1～5脊柱三维有限元模型,形成8节点6面体单元496个,共1006个节点,按不同材料参数仿真脊柱各部结构,并仿真腰段活动进行加载。结论建立完整脊柱腰段三维有限元模型,能够分析脊柱前屈、后伸、侧屈、旋转等多种情况下各部的应力分布及位移量,以探讨腰段脊柱损伤应力的病理机制。

Objective The three-dimension analytical method of finite element was used to set u p a new.3-D finite element mod-el.Method We measured the surface nodes of 3-D l umbar spine of human corpse and artif icially divided the lumbar spine int o 496units(including 1006nodes)according to the finite division regular of 3-D coordinate system of lumb ar spine model.We also measured the d istance and section of some muscles for examp le,psoas major muscle,quadratus lu mborum,erector spinae oblique,int ernal abdominal oblique,rectus abdominis,transverses abdominis.Through calculation of the moment of force,we achieved the force of muscle,which was downloaded in the model.Results Hazard stress was showed in lumbar sp ine under different postures especially for lumbar pedicle.The cause of lumbar spine common disease will depend on this re sult by using the relationship of str ess and strain.Conclusion The new 3-D finite element model of whole lumbar vertebral column with muscles is exactly the same as human an atomy.It will be the reference for cu ring common disease of lumbar spine.