膜单元与弹簧单元模拟韧带损伤的生物力学响应

目的对比分析膜单元与弹簧单元对颈部韧带生物力学响应的影响。方法基于现有的6岁儿童颈部有限元模型,将其中的韧带分别用膜与弹簧两种单元类型模拟,进行儿童颈椎C4～5椎段动态拉伸实验和全颈椎拉伸实验。同时采用膜单元模型进行弯曲仿真试验,并分析仿真效果。结果在C4～5椎段动态拉伸实验中,膜单元仿真与弹簧单元仿真最终失效力分别为1 207、842 N,与尸体实验分别相差0. 6%、30. 6%;在全颈椎拉伸实验中,膜单元仿真峰值力与尸体实验相差1. 8%,弹簧单元仿真峰值力为484 N,与尸体实验相差较大。膜单元弯曲试验仿真效果良好。结论弹簧单元在模拟受力方面存在一定局限性,而膜单元具有较高的生物仿真度,更能体现韧带的生物力学响应。

Biomechanical Response of Membrane Element and Spring Element for Simulation of Ligament Injury

Objective To compare and analyze the effect of membrane element and spring element on biomechanical responses of cervical ligaments. Methods Based on the existing 6-year-old pediatric neck finite element model, the ligaments were simulated by membrane element and spring element, respectively. Then dynamic tensile test of C4-5 vertebrae and tensile test of full cervical spine were conducted. The membrane element model was also used to simulate the bending test, and the simulation results were analyzed. Results In dynamic tensile test of C4-5 vertebral segment, the final failure force of membrane element simulation test and spring element simulation test was 1 207 N and 842 N, respectively, and their difference from the cadaver experiment was 0.6% and 30.6%, respectively. In full cervical tensile test, the difference of peak force from membrane element simulation test and cadaver experiment was 1.8%. The peak force of spring element simulation test was 484 N, and the difference from simulation test and cadaver experiment was large. The simulation result of membrane element bending test was good. Conclusions The spring element had some limitations in force simulation. The membrane element had higher biofidelity and could reflect the biomechanical response of the ligaments.