Derwin K A, Soslowsky L J, Green W D, Elder S H
Orthopaedic Research Laboratories, University of Michigan, Ann Arbor 48109-0486.
J Biomech. 1994 Oct;27(10):1277-85. doi: 10.1016/0021-9290(94)90281-x.
Many types of optical strain measurement systems have been used for the determination of deformations and strains in soft biological tissues. The purpose of this investigation is to report a new optical strain measurement system developed in our laboratory which offers distinct advantages over systems developed in the past. Our optical strain system has demonstrated excellent performance in calibration and experimental tests. Calibration tests illustrate the system's accuracy to 0.05% strain at 3.52% strain and 0.18% strain at 11.74% strain. Further, this system can measure strains to within 2% measurement error for strains in a 0-11.74% range when 100 microns increments of motion are used for calibration. The resolution of our system appears to be at least as good as the linear micrometer (2 microns) used as a calibrating standard. Errors in strain measurement due to whole specimen rotation or translation are quantified. Rotations about an in-plane axis perpendicular to the direction of strain and translations in/out of the plane of focus result in the largest sources of error. Finally, in an in vitro biomechanical study of the rabbit Achilles tendon, experimental failure strains are 4.3 +/- 0.9% using this system.
许多类型的光学应变测量系统已被用于测定软生物组织中的变形和应变。本研究的目的是报告我们实验室开发的一种新型光学应变测量系统，该系统相对于过去开发的系统具有明显优势。我们的光学应变系统在校准和实验测试中表现出优异的性能。校准测试表明，该系统在3.52%应变时的精度为0.05%应变，在11.74%应变时的精度为0.18%应变。此外，当使用100微米的运动增量进行校准时，该系统在0-11.74%应变范围内测量应变的误差可控制在2%以内。我们系统的分辨率似乎至少与用作校准标准的线性千分尺（2微米）一样好。对由于整个样本旋转或平移导致的应变测量误差进行了量化。绕垂直于应变方向的平面内轴的旋转以及在焦平面内/外的平移是最大的误差来源。最后，在兔跟腱的体外生物力学研究中，使用该系统测得的实验破坏应变为4.3±0.9%。
