MEASUREMENT OF 3D STRAIN IN BONE BY TEXTURE CORRELATION

描述（改编自申请人的摘要）：本申请的 目的是开发一种无创测量三维应变的方法， 具有内部纹理的固体物体，特别是松质和皮质 骨头 实体内部的点的位置将使用 X射线层析显微镜，使用单色同步加速器X射线。 这些 一种机器的分辨率比“微型CT”高出几倍 机械. 固体中的位移和应变将使用 “纹理相关”，作者开发的跟踪方法 具有纹理的物体（例如松质骨）中的可识别点，以及 从位移场计算应变。 经过进一步发展， 计算机算法将该方法从2D扩展到3D， 并将进行分析，以评估的准确性和敏感性， 法 在第一个系列中，将测试均匀的泡沫材料， 单轴压缩 均匀圆柱体和带孔固体 会得到考验 模拟测试的有限元模型将 构建和分析。 将有限元模型结果进行比较 用纹理相关方法作为评估 后者 然后将在松质骨上进行相同的手术， 猪的椎骨体和胫骨近端。 材料性能将是 根据公布的刚度/密度数据估计。 最后，一系列 来自XTM的较粗糙的数据集将用于评估 纹理数据需要得到可接受的分辨率和精度的方法。 分辨率较低的方法，如微型CT，可能 采取适当的应变措施。

DESCRIPTION (Adapted from the applicant's Abstract): This application's goal is to develop a method for noninvasive measurement of 3D strain in solid objects with internal texture, particularly cancellous and cortical bone. The location of points internal to the solid will be determined using X-ray Tomographic Microscopy, using monochromatic synchrotron x-rays. These type of machines have resolutions several times greater than the "micro CT" machines. Displacement and strain in the solid will be determined using "texture correlation", a method developed by the authors for tracking identifiable points in an object with texture, such as cancellous bone, and computing strain from the displacement fields. After further development of computer algorithms to extend the method from 2D to 3D, a series of tests and analyses will be done to assess the accuracy and sensitivity of the method. In the first series, a uniform foam material will be tested in uniaxial compression. Both homogeneous cylinders and solids with a hole will be tested. A finite element model simulating the test will be constructed and analyzed. The finite element model results will be compared with the texture correlation method as a means of assessing the accuracy of the latter. The same procedure will then be done on cancellous bone from the vertebral body and proximal tibia of a pig. Material properties will be estimated from published stiffness/density data. Finally, a series of coarser data sets from the XTM will be used to assess the resolution of texture data needed to get acceptable resolution and accuracy of the method. It is possible that methods with less resolution, such as micro-CT, could give adequate strain measures.