Mechanical characterization of the bovine iris
Mechanical characterization of the bovine iris
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DOI：
10.1016/s0021-9290(99)00075-5
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发表时间：
1999-09-01
影响因子：
2.4
通讯作者：
Barocas, VH
中科院分区：
文献类型：
--
作者：
Heys, J;Barocas, VH
虹膜的机械特性的量化是必要的，以评估被动虹膜变形的临床意义，这已被认为是某些形式的青光眼的机制。在离体牛虹膜上进行伸展试验，以确定虹膜的被动力学行为及其两个组成肌肉（虹膜括约肌和瞳孔扩张肌）对整体性能的贡献。由于虹膜的形状和我们希望使用完整的组织，进行了一个“环”实验，其中虹膜通过钩住样品并拉动来拉伸。一个简单的数学模型被用来解释实验的几何形状和组织的渐进募集。还对从虹膜解剖的样品进行了径向延伸实验。虹膜被发现是各向异性的，弹性的，和不可压缩的。发现括约肌的平均方位角杨氏模量为340 kPa;发现扩张器的平均方位角杨氏模量为890 kPa，其显著更高（p < 0.01）。扩张器的径向杨氏模量为9.6 kPa，远低于方位角值。(C)1999 Elsevier Science Ltd.保留所有权利。
Quantification of the mechanical properties of the iris is necessary to assess the clinical significance of passive iris deformation, which has been suggested as a mechanism for certain forms of glaucoma. Extension tests were performed on isolated bovine irises to determine the passive mechanical behavior of the iris and the contribution of each of its two constituent muscles, the sphincter iridis and the dilator pupillae, to the overall properties. Because of the shape of the iris and our desire to use intact tissue, a "loop" experiment was performed in which the iris was stretched by hooking the sample and pulling. A simple mathematical model was used to account for the geometry of the experiment and the progressive recruitment of tissue. Radial extension experiments on samples dissected from the iris were also performed. The iris was found to be anisotropic, elastic, and incompressible. The average azimuthal Young's modulus of the sphincter was found to be 340 kPa; the average azimuthal Young's modulus of the dilator was found to be 890 kPa, which was significantly higher (p < 0.01). The radial Young's modulus of the dilator was found to be 9.6 kPa, much lower than the azimuthal value. (C) 1999 Elsevier Science Ltd. All rights reserved.