Dickinson A S, Taylor A C, Ozturk H, Browne M
Bioengineering Research Group, University of Southampton, Highfield, Southampton, Hants, UK.
J Biomech Eng. 2011 Jan;133(1):014504. doi: 10.1115/1.4003129.
Computational biomechanical models are useful tools for supporting orthopedic implant design and surgical decision making, but because they are a simplification of the clinical scenario they must be carefully validated to ensure that they are still representative. The goal of this study was to assess the validity of the generation process of a structural finite element model of the proximal femur employing the digital image correlation (DIC) strain measurement technique. A finite element analysis model of the proximal femur subjected to gait loading was generated from a CT scan of an analog composite femur, and its predicted mechanical behavior was compared with an experimental model. Whereas previous studies have employed strain gauging to obtain discreet point data for validation, in this study DIC was used for full field quantified comparison of the predicted and experimentally measured strains. The strain predicted by the computational model was in good agreement with experimental measurements, with R(2) correlation values from 0.83 to 0.92 between the simulation and the tests. The sensitivity and repeatability of the strain measurements were comparable to or better than values reported in the literature for other DIC tests on tissue specimens. The experimental-model correlation was in the same range as values obtained from strain gauging, but the DIC technique produced more detailed, full field data and is potentially easier to use. As such, the findings supported the validity of the model generation process, giving greater confidence in the model's predictions, and digital image correlation was demonstrated as a useful tool for the validation of biomechanical models.
计算生物力学模型是支持骨科植入物设计和手术决策的有用工具，但由于它们是临床场景的简化形式，因此必须仔细验证以确保其仍具有代表性。本研究的目的是评估采用数字图像相关（DIC）应变测量技术生成的股骨近端结构有限元模型的有效性。通过对模拟复合股骨的CT扫描生成了承受步态负荷的股骨近端有限元分析模型，并将其预测的力学行为与实验模型进行了比较。以往的研究采用应变片来获取离散点数据进行验证，而在本研究中，DIC用于对预测应变和实验测量应变进行全场量化比较。计算模型预测的应变与实验测量结果吻合良好，模拟与测试之间的R(2)相关值在0.83至0.92之间。应变测量的灵敏度和可重复性与文献中报道的其他组织标本DIC测试的值相当或更好。实验模型相关性与应变片测量得到的值在同一范围内，但DIC技术产生了更详细的全场数据，并且可能更易于使用。因此，这些发现支持了模型生成过程的有效性，增强了对模型预测的信心，并且数字图像相关被证明是验证生物力学模型的有用工具。
