Sarma P A, Pidaparti R M, Meiss R A
Department of Mechanical Engineering, Purdue School of Engineering and Technology, IUPUI, 723 W. Michigan Street, Indianapolis, IN 46202-5132, USA.
J Biomed Mater Res A. 2003 Apr 1;65(1):1-8. doi: 10.1002/jbm.a.10355.
The anisotropic (directional-dependent) properties of contracting tracheal smooth muscle tissue are estimated from a computational model based on the experimental data of length-dependent stiffness. The area changes are obtained at different muscle lengths from experiments in which stimulated muscle undergoes unrestricted shortening. Then, through an interative process, the anisotropic properties are estimated by matching the area changes obtained from the finite element analysis to those derived from the experiments. The results obtained indicate that the anisotropy ratio (longitudinal stiffness to transverse stiffness) is about 4 when the smooth muscle undergoes 70% strain shortening, indicating that the transverse stiffness reduces as the longitudinal stiffness increases. It was found through a sensitivity analysis from the simulation model that the longitudinal stiffness and the in-plane shear modulus are not very sensitive as compared to major Poisson's ratio to the area changes of the muscle tissue.
基于长度依赖性刚度的实验数据，通过计算模型估算收缩期气管平滑肌组织的各向异性（方向依赖性）特性。在刺激肌肉进行无限制缩短的实验中，于不同肌肉长度下获得面积变化。然后，通过迭代过程，将有限元分析得到的面积变化与实验得出的面积变化进行匹配，从而估算出各向异性特性。所得结果表明，当平滑肌发生70%应变缩短时，各向异性比率（纵向刚度与横向刚度之比）约为4，这表明横向刚度随纵向刚度的增加而降低。通过模拟模型的敏感性分析发现，与主泊松比相比，纵向刚度和面内剪切模量对肌肉组织面积变化的敏感性不是很高。
