In this study, we developed an equi-load biaxial tensile tester and applied it to a series of mechanical tests using specimens obtained from the porcine spinal dura mater. The dural sample exhibited a nonlinear and anisotropic behavior as it was more deformable in the longitudinal direction rather than in the circumferential direction at lower strains; i.e., mechanical response of the longitudinal direction was significantly compliant in the Toe region compared to that of the circumferential direction under 1:1 biaxial stretching. However, we have not observed a significant difference with respect to the resultant strain and Young’s modulus between the longitudinal and circumferential directions at higher strains or in the Linear region. Our results also indicated that the upper thoracic region (T1) was relatively compliant compared to the lumbar region (L), where the failure load was almost equal between them because the dural thickness of T1 was five-fold greater than that of L; i.e., spinal dura mater became stiffer and stronger at further distances from the brain. This shows structural effectiveness and may be preferable to mechanically protect the vulnerable spinal cord from externally applied impact loads.

中文翻译：

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使用 PD 控制的双轴拉伸试验机对脊髓硬膜进行机械表征

在这项研究中，我们开发了一种等负载双轴拉伸试验机，并使用从猪硬脊膜获得的样品将其应用于一系列力学试验。硬脑膜样品表现出非线性和各向异性行为，因为它在较低应变下在纵向而不是在圆周方向更易变形；即，在 1:1 双轴拉伸下，与圆周方向的机械响应相比，脚趾区域的纵向机械响应显着柔顺。然而，我们没有观察到在较高应变或线性区域中纵向和圆周方向之间的合成应变和杨氏模量的显着差异。我们的研究结果还表明，与腰椎区域（L）相比，上胸部区域（T1）相对柔顺，因为 T1 的硬脑膜厚度是 L 的 5 倍，因此它们之间的破坏载荷几乎相等；即，在离大脑更远的地方，硬脊膜变得更硬更强壮。这显示了结构有效性，并且可能更适合机械地保护脆弱的脊髓免受外部施加的冲击载荷。