Boschetti F, Triacca V, Spinelli L, Pandolfi A
Laboratory of Biological Structure Mechanics, Dipartimento di Ingegneria Strutturale, Politecnico di Milano, Milano, Italy.
J Biomech Eng. 2012 Mar;134(3):031003. doi: 10.1115/1.4006089.
An experimental program has been carried out in order to investigate the mechanical behavior of porcine corneas. We report the results of inflation tests on the whole cornea and uniaxial tests on excised corneal strips, performed on 51 fresh porcine eyes. Uniaxial tests have been performed on specimens cut from previously inflated corneas. The cornea behavior is characterized by means of elastic stiffness, measured on both average pressure-apex displacement and average uniaxial stress-strain curves; and by means of transversal contraction coefficient, peak stress, and failure stress measured on uniaxial stress-strain curves. Uniaxial tests performed on excised strips allowed to measure the anisotropy in the corneal stiffness and to compare the stiffness of the cornea with the one of the sclera. Viscous properties of the cornea have been obtained through uniaxial relaxation curves on excised corneal strips. The relevant geometrical parameters have been measured and, with the aid of the elastic thin shell theory, a stress-strain curve has been derived from the average inflation test data and compared with similar data available in the literature. The experimental system has been developed in view of future applications to the mechanical testing of both porcine and human corneas.
为了研究猪角膜的力学行为，开展了一个实验项目。我们报告了对51只新鲜猪眼进行的全角膜膨胀试验和离体角膜条单轴试验的结果。单轴试验是在从先前膨胀的角膜上切下的标本上进行的。角膜行为通过弹性刚度来表征，弹性刚度是在平均压力-顶点位移和平均单轴应力-应变曲线上测量的；还通过在单轴应力-应变曲线上测量的横向收缩系数、峰值应力和破坏应力来表征。对离体条带进行的单轴试验能够测量角膜刚度的各向异性，并将角膜的刚度与巩膜的刚度进行比较。角膜的粘性特性是通过对离体角膜条的单轴松弛曲线获得的。测量了相关的几何参数，并借助弹性薄壳理论，从平均膨胀试验数据中导出了应力-应变曲线，并与文献中可得的类似数据进行了比较。鉴于未来在猪角膜和人角膜力学测试中的应用，开发了该实验系统。
