国家自然科学基金项目 (32171304, 31370952, 31470914)
目的 比较基于快、慢速加载单轴拉伸数据确定的角膜生物力学特性参数。方法 选取15只健康成年兔的角膜进行平均加载速率为0.16、0.02 mm/s单轴拉伸实验，分别获得应力-应变以及应力松弛数据；分别利用黏超弹性模型、1阶Ogden模型和2阶Prony级数模型对加卸载迟滞环曲线、应力-应变曲线、应力松弛曲线进行分析。基于黏超弹性模型拟合快速加卸载迟滞环曲线确定的参数集记为Gvh。拟合慢速加载的应力-应变、应力松弛数据的材料参数集记为GOP。利用相关性分析比较Gvh与GOP之间参数的相关性。结果对快速加卸载迟滞环数据、慢速加载的应力应变数据与应力松弛数据的拟合优度R2都大于0.95。Gvh与GOP中6个参数中5个（μ，A1，A2，τ1，τ2）差异明显（P<005），并且两参数组中Ogden模型参数呈正相关。结论 基于快、慢速加载的单轴拉伸数据识别的角膜生物力学参数具有差异性。研究结果为进一步探索利用临床数据识别角膜生物力学特性提供前期的研究基础。
Objective To compare the corneal biomechanical parameters identified from uniaxial tensile test under fast and slow loading. Methods The stress-strain and stress relaxation data were obtained from uniaxial tensile tests on corneal strips from 15 healthy adult rabbits at average loading rate of 0.16 mm/s and 0.02 mm/s, respectively. A visco-hyperelastic model was applied to analyze the loading and unloading data from the fast tensile tests, where the model parameter set was denoted by Gvh. The first-order Ogden model and second-order Prony series model were used to fit stress-strain and stress relaxation data from the slow tensile tests, respectively, in which the model parameter set was denoted by Gvh. Correlation analysis was used to compare the correlation of parameters between Gvh and GOP. Results All the goodness-of-fits to the three data sets were greater than 0.95. There were significant differences in 5 (μ, A1, A2, τ1, τ2,) of the 6 parameters between Gvh and GOP (P<0.05), and the Ogden model parameters was positively correlated between the two groups. Conclusions There are differences in corneal biomechanical parameters identified by data from uniaxial tensile tests under fast and slow loading. The results provide a preliminary research basis for further exploring the use of clinical data to identify corneal biomechanical properties.