NEW METHOD TO DETERMINE SPONGY BONE TISSUE STIFFNESS

描述（改编自申请人的摘要）： 生物力学中，数学模型通常用于间接计算 完整结构测试结果的材料特性。 传统上， 这些模型局限于简单的结构，例如柱，梁， 和管子。 在过去的几年里，大规模计算机的出现 方法在计算力学，结合自动体素为基础的 基于微层析数据集的网格化技术， 为了将该方法扩展到确定组织或成分 大孔泡沫的材料特性，如松质骨或海绵骨。 研究人员建议使用一个 松质骨的多孔机械模拟物。 这些类似物是由 热塑性材料，其已经用添加剂处理以使其 X射线吸收。 空隙是通过将石蜡珠粒与 材料，因为它是形成的，后来融化和删除。 高 分辨率Micro-CT扫描将由类似物和基于体素的 有限元（FE）模型由所得数据制备。 组合时 通过对每个样品进行直接力学测试， 通过优化间接计算组成刚度 procedure. 然后可以将预测的刚度与已知的刚度进行比较。 无空隙塑料的刚度作为测量 法 虽然这种新颖的结合尖端技术从两个不同的 领域（FE分析和Micro-CT）有很大的希望，这种方法是 完全未经测试，也没有量化的准确性， 企图。 研究人员建议，如果这项技术可以 经过验证，它将在骨科领域产生巨大的影响， 一般和大孔径泡沫的研究，特别是。

DESCRIPTION (Adapted from applicant's abstract): In the field of biomechanics, mathematical models are often used to indirectly compute material properties from test results of intact structures. Traditionally, these models have been limited to simple structures such as column, beams, and tubes. In the last few years, the advent of large-scale computer methods in computational mechanics, combined with automated voxel-based meshing techniques based on microtomographic datasets, have made it possible to expand this approach to the determination of tissue or constituent material properties for large-pore foams such as cancellous or spongy bone. The investigator proposes to quantify the accuracy of this approach using a porous mechanical analogue to cancellous bone. The analogues are made of a thermoplastic material which has been treated with an additive to make it x-ray absorptive. Voids are produced by including paraffin beads with the material as it is formed, which are later melted and removed. High resolution Micro-CT scans will be made of the analogues, and voxel-based finite element (FE) models prepared from the resulting data. When combined with direct mechanical testing of each sample, the FE models allow the constituent stiffness to be computed indirectly by an optimization procedure. The predicted stiffness can then be compared with the known stiffness of the void-free plastic as a measure for the accuracy of the method. Although this novel combination of cutting-edge technology from two distinct fields (FE analysis and Micro-CT) holds great promise, this approach is totally untested and no quantification of its accuracy has ever been attempted. The investigators suggest that if the technique can be validated, it will have an enormous impact in the field of orthopaedics, in general and as the study of large-pore size foams, in particular.