在体兔眼虹膜材料模型的确定

Determination of material model for the rabbit iris in vivo

目的:确定适合表征在体虹膜力学行为的材料模型。方法:基于在体动物实验,建立眼前节有限元模型。假设虹膜材料分别为线弹性模型、Neo-Hookean模型和二阶Ogden模型,参考相应文献,设定材料参数范围,计算对应的虹膜特征点位移。基于在体实验的测量结果,利用目标函数,比较不同模型间的差异。结果:二阶Ogden模型对应的目标函数的最小值和平均值均最小,Neo-Hookean模型次之,线弹性模型的最大。结论:3种模型相比,二阶Ogden模型最适合用于描述在体虹膜的力学行为。

Objective To determine the optimal material model for describing the mechanical responses of the rabbit iris in vivo.Methods Based on the in vivo animal experiments,the finite element model of the anterior segment was established.Three different models,namely linear elastic model,Neo-Hookean model and second-order Ogden model,were taken as the material model of the rabbit iris in vivo.The ranges of material parameters were determined according to related references,and the displacements of the characteristic points were calculated.Based on the results of in vivo experiments,the differences among 3 different models were compared using objective functions.Results The minimum and average values of the objective functions for linear elastic model were the maximum,followed by Neo-Hookean model and second-order Ogden model.Conclusion Among the 3 models,second-order Ogden model is the optimal material model for describing the mechanical responses of the rabbit iris in vivo.