The pipette aspiration applied to the local stiffness measurement of soft tissues
The pipette aspiration applied to the local stiffness measurement of soft tissues
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DOI：
10.1007/bf02684197
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发表时间：
1997-05-01
影响因子：
3.8
通讯作者：
Sato, M
中科院分区：
文献类型：
--
作者：
Aoki, T;Ohashi, T;Sato, M
一种确定应力-应变曲线初始斜率的简单方法（即，软组织的杨氏模量）通过引入吸管抽吸技术。假设组织是各向同性的，并且在宏观上是均匀的。线性有限元分析的数值模拟进行了调查的影响，在组织移液管接触边界，移液管横截面的几何形状，相对大小的试样的移液管，和分层的不均匀性的试样组织的轴对称模型。接触区的摩擦力对杨氏模量的测量影响不大。移液管的配置被证明会影响小移液管壁厚的测量。对于相对较小的样本，测量还取决于样本与移液管的相对大小。有助于测量的区域的范围大约是移液管内径的两倍。在该区域，最大应力没有超过抽吸压力的水平，只有少数例外的位置。应变能分量的计算表明，吸管抽吸下的变形主要是由吸管轴向的法向拉伸和剪切变形。实验验证本方法的各向同性，均匀的人造材料。
A simple method of identifying the initial slope of the stress-strain curve (i.e., Young's modulus of the soft tissue) by introducing the pipette aspiration technique is presented. The tissue was assumed to be isotropic and macroscopically homogeneous. Numerical simulations by the linear finite element analysis were performed for the axisymmetric model to survey the effects of friction at the tissue-pipette contact boundary, pipette cross-sectional geometry, relative size of the specimen to the pipette, and the layered inhomogeneity of the specimen tissue. The friction at the contact region had little effect on the measurement of Young's modulus. The configuration of the pipette was shown to affect the measurement for small pipette wall thickness. The measurement also depended on the relative size of the specimen to the pipette for relatively small specimens. The extent of the region contributing to the measurement was roughly twice the inside radius of the pipette. In this region, the maximum stress did not exceed the level of the aspiration pressure, with only minor exceptional locations. Calculation of strain energy components indicated that the major contributions to the deformation under pipette aspiration were by the normal extension and shear deformation in pipette axial direction. Experimental verification of the present method for the isotropic, homogeneous artificial material is also presented.