Determination of Elastic Modulus in Mouse Bones Using a Nondestructive Micro-Indentation Technique Using Reference Point Indentation
Determination of Elastic Modulus in Mouse Bones Using a Nondestructive Micro-Indentation Technique Using Reference Point Indentation
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使用参考点压痕的无损微压痕技术测定小鼠骨骼的弹性模量
DOI：
10.1115/1.4039982
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Johnson, Mark L.
中科院分区：
文献类型：
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作者：
Thiagarajan, Ganesh;Begonia, Mark T.;Dallas, Mark;Lara-Castillo, Nuria;Scott, JoAnna M.;Johnson, Mark L.
骨弹性模量的测定对于研究骨对载荷的响应非常重要，并且使用破坏性三点弯曲法来测定。参考点压痕 (RPI) 具有一个压痕周期，为确定弹性模量提供了一种无损替代方法。虽然可以使用离体实验的无损程序确定弹性模量，但对于体内测试，三点弯曲技术可能不实用，因此 RPI 被视为潜在的替代方案并在本研究中进行了探索。利用 RPI 测量值、总压痕距离 (TID)、蠕变压痕距离、压痕力和卸载斜率，我们开发了一种使用 Oliver–Pharr (O/P) 方法来估计压痕弹性模量的数值分析程序。使用两种方法来确定面积函数：(1) Oliver-Pharr（O/P——基于数值程序）和（2）几何方法（基于压痕投影面积的计算）。通过O/P（3.49-3.68 GPa）和几何（3.33-3.49 GPa）方法计算的聚甲基丙烯酸甲酯（PMMA）的压痕模量与文献中的值（3.5-4 GPa）相似。在一项使用不同年龄和性别的 C57Bl/6 小鼠股骨的研究中，三点弯曲模量低于压痕模量。在4至5个月大的TOPGAL小鼠股骨中，我们发现几何（5.61±1.25 GPa）和O/P（5.53±1.27 GPa）方法的压痕模量高于三点弯曲模量（5.28±0.34 GPa）。在女性中，几何（7.45±±0.86 GPa）和O/P（7.46±±0.92 GPa）方法的压痕模量也高于三点弯曲模量（7.33±±1.13 GPa）。从这项研究中我们可以得出结论，RPI 确定的值相对接近三点弯曲值。
The determination of the elastic modulus of bone is important in studying the response of bone to loading and is determined using a destructive three-point bending method. Reference point indentation (RPI), with one cycle of indentation, offers a nondestructive alternative to determine the elastic modulus. While the elastic modulus could be determined using a nondestructive procedure for ex vivo experiments, for in vivo testing, the three-point bending technique may not be practical and hence RPI is viewed as a potential alternative and explored in this study. Using the RPI measurements, total indentation distance (TID), creep indentation distance, indentation force, and the unloading slope, we have developed a numerical analysis procedure using the Oliver–Pharr (O/P) method to estimate the indentation elastic modulus. Two methods were used to determine the area function: (1) Oliver–Pharr (O/P—based on a numerical procedure) and (2) geometric (based on the calculation of the projected area of indentation). The indentation moduli of polymethyl methacrylate (PMMA) calculated by the O/P (3.49–3.68 GPa) and geometric (3.33–3.49 GPa) methods were similar to values in literature (3.5–4 GPa). In a study using femurs from C57Bl/6 mice of different ages and genders, the three-point bending modulus was lower than the indentation modulus. In femurs from 4 to 5 months old TOPGAL mice, we found that the indentation modulus from the geometric (5.61 ± 1.25 GPa) and O/P (5.53 ± 1.27 GPa) methods was higher than the three-point bending modulus (5.28 ± 0.34 GPa). In females, the indentation modulus from the geometric (7.45 ± 0.86 GPa) and O/P (7.46 ± 0.92 GPa) methods was also higher than the three-point bending modulus (7.33 ± 1.13 GPa). We can conclude from this study that the RPI determined values are relatively close to three-point bending values.