Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA.
Acta Biomater. 2010 Nov;6(11):4327-35. doi: 10.1016/j.actbio.2010.06.007. Epub 2010 Jun 15.
An in vitro inflation test method was developed to characterize the mechanical behavior of the bovine posterior sclera. The method used digital image correlation to provide a spatially resolved, full-field deformation map of the surface of the posterior sclera in response to controlled pressurization. A series of experiments were performed in the range of 2-6 kPa (15-45 mmHg) to characterize the load-unload displacement response at various pressure rates and the time-dependent displacement response at different applied pressures. The magnitude of the displacement was largest in the peripapillary region, mainly between the apex and the optic nerve head. Further, the results showed that bovine scleral tissue exhibited nonlinear and viscoelastic behavior characterized by a rate-dependent displacement response, hysteresis during unloading and creep. The creep rate was insensitive to the applied pressure, suggesting that the tissue can be modeled as a quasilinear viscoelastic material in the physiological pressure range of 2-6 kPa.
开发了一种体外膨胀测试方法来描述牛眼后巩膜的力学行为。该方法使用数字图像相关技术，提供了后巩膜表面在受控加压下的空间分辨、全场变形图。在 2-6 kPa（15-45 mmHg）范围内进行了一系列实验，以表征在不同压力率下的加载-卸载位移响应，以及在不同施加压力下的时变位移响应。在视盘周围区域，主要在顶点和视神经头部之间，位移幅度最大。此外，结果表明牛眼巩膜组织表现出非线性和粘弹性行为，其特征是位移响应与速率有关、卸载时出现滞后以及存在蠕变。蠕变速率与施加的压力无关，这表明在 2-6 kPa 的生理压力范围内，组织可以被建模为拟线性粘弹性材料。
