Development of an Inertia-Driven Model of Sideways Fall for Detailed Study of Femur Fracture Mechanics
Development of an Inertia-Driven Model of Sideways Fall for Detailed Study of Femur Fracture Mechanics
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DOI：
10.1115/1.4025390
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发表时间：
2013-12-01
影响因子：
1.7
通讯作者：
Cripton, Peter A.
中科院分区：
文献类型：
--
作者：
Gilchrist, Seth;Guy, Pierre;Cripton, Peter A.
开发了一种在模拟侧向跌倒的条件下对人体近端股骨进行实验室测试的新方法。此外，为了分析未来尸体测试中的应变状态，数字图像相关（DIC）被验证为股骨颈骨应变场测量的工具。设计了一个跌倒模拟器，其中包括体重、股骨外侧和骨盆质量、骨盆刚度和转子软组织的模型。每个元素的特征都是根据文献中的人类数据得出和开发的。通过加载最先进的替代股骨并将所得的力-时间轨迹与已发表的人类志愿者实验进行比较来验证模拟器。为了验证 DIC，使用应变玫瑰花和斑点涂料图案制备了 20 个人类近端股骨，并以低压缩率加载至其预测失效载荷的 50%。将应变玫瑰花结作为黄金标准，并使用描述性统计比较 DIC 和玫瑰花结的最小主应变。在跌倒模拟器中获得的力-时间曲线的初始斜率与已发布的人类志愿者数据相匹配，由于用于模拟骨盆刚度的弹簧的内部振动，模型中叠加了局部峰值。总体力大小和时间特征与已发表的志愿者实验的误差在 2% 以内。发现 DIC 最小主应变精确至 1276239 le。这些工具将允许对侧面跌倒进行更逼真的实验室模拟，并使用人体尸体标本对股骨近端衰竭机制进行更详细的分析。
A new method for laboratory testing of human proximal femora in conditions simulating a sideways fall was developed. Additionally, in order to analyze the strain state in future cadaveric tests, digital image correlation (DIC) was validated as a tool for strain field measurement on the bone of the femoral neck. A fall simulator which included models for the body mass, combined lateral femur and pelvis mass, pelvis stiffness, and trochanteric soft tissue was designed. The characteristics of each element were derived and developed based on human data from the literature. The simulator was verified by loading a state-of-the-art surrogate femur and comparing the resulting force-time trace to published, human volunteer experiments. To validate the DIC, 20 human proximal femora were prepared with a strain rosette and speckle paint pattern, and loaded to 50% of their predicted failure load at a low compression rate. Strain rosettes were taken as the gold standard, and minimum principal strains from the DIC and the rosettes were compared using descriptive statistics. The initial slope of the force-time curve obtained in the fall simulator matched published human volunteer data, with local peaks superimposed in the model due to internal vibrations of the spring used to model the pelvis stiffness. Global force magnitude and temporal characteristics were within 2% of published volunteer experiments. The DIC minimum principal strains were found to be accurate to 1276239 le. These tools will allow more biofidelic laboratory simulation of falls to the side, and more detailed analysis of proximal femur failure mechanisms using human cadaver specimens.