A Pointwise Method for Identifying Biomechanical Heterogeneity of the Human Gallbladder.
A Pointwise Method for Identifying Biomechanical Heterogeneity of the Human Gallbladder.
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DOI：
10.3389/fphys.2017.00176
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发表时间：
2017
影响因子：
4
通讯作者：
Luo X
中科院分区：
文献类型：
--
作者：
Li W;Bird NC;Luo X
从非侵入性测量中识别人类胆囊（GB）壁的异质生物力学特性可以在患者特定建模和非结石性胆痛诊断中具有临床意义。本文提出了一种逐点测量10份人血淋巴细胞再灌注过程中异质性的方法。选择三个不同的点，两个在GB体的赤道上，相隔90°，一个在GB基底的顶点上，代表典型的感兴趣区域。在这些点的拉伸估计从超声图像的GB在胆汁排空阶段的基础上的分析模型。利用羔羊GB的实验数据对该模型进行了验证。利用基于结构的各向异性本构模型，反求了不同点的材料参数。这种各向异性模型产生了更好的准确性相比，一些唯象为本构定律，其显着降低最小二乘误差应力曲线拟合证明。结果证实，人GB壁材料是异质的，特别是朝向顶点区域。我们的研究还表明，非均匀壁厚的GB是重要的，在确定的材料参数，特别是在与基体和纵向纤维的属性相关的参数的差异可以高达20-30%相比，均匀厚度模型。
Identifying the heterogeneous biomechanical property of human gallbladder (GB) walls from non-invasive measurements can have clinical significance in patient-specific modeling and acalculous biliary pain diagnosis. In this article, a pointwise method was proposed to measure the heterogeneity of ten samples of human GB during refilling. Three different points, two on the equator of GB body 90° apart and one on the apex of GB fundus, were chosen to represent the typical regions of interest. The stretches at these points were estimated from ultrasound images of the GB during the bile emptying phase based on an analytical model. The model was validated against the experimental data of a lamb GB. The material parameters at the different points were determined inversely by making use of a structure-based anisotropic constitutive model. This anisotropic model yielded much better accuracy when compared to a number of phenomenologically-based constitutive laws, as demonstrated by its significantly reduced least-square errors in stress curve fitting. The results confirmed that the human GB wall material was heterogeneous, particularly toward the apex region. Our study also suggested that non-uniform wall thickness of the GB was important in determining the material parameters, in particular, on the parameters associated with the properties of the matrix and the longitudinal fibers—the difference could be as large as 20–30% compared to that of the uniform thickness model.