髓核假体的四元线性黏弹模型及制备参数对模型参数的影响分析

对聚乙烯醇水凝胶髓核假体进行应力松弛性能的研究,利用四元件线性黏弹力学模型对其黏弹性力学行为进行模拟,并从模型的模拟结果分析不同制备参数对髓核假体消散压缩载荷的能力的影响。研究结果表明:四元件线性黏弹模型能够很好的模拟髓核假体的黏弹特性,拟合度达到了0．99以上,效果优于三元件线性黏弹模型。四元件线性黏弹模型的分析结果表明:溶胀率的增大可以增加髓核假体消散压缩载荷的速度,但不能改变消散压缩载荷的总量;初始PVA含量越高,髓核假体消散压缩载荷的速度和总量越小;髓核假体松弛时间与人体椎间盘的松弛时间比较接近。

Analysis of the Four Parameter Linear Viscoelastic Model on Prosthetic Nucleus and the Influence of Manufacture on Parameters of This Model

The purpose of this study is to characterize the stress relax properties of PVA-H prosthetic nucleus via the four-parameter linear viscoelastic model and to analyze the influence of swelling ratio and initial PVA content upon the properties of dissipating compressive stress. The four-parameter linear viscoelastic model can simulate the viscoelastic property of prosthetic nucleus well (corr>0. 99) and be more effective than the three parameter linear viscoelastic model. From the parameters of this model we have obtained the following results; the prosthetic nucleus of higher water content can dissipate compressive stress more quickly than that of lower water content can do, but the quantity of stress relax can not be influenced by water content; the higher the initial PVA content,the slower and smaller the dissipation of compressive stress;the relax time of prosthetic nucleus is similar to that of human nucleus.