Fung Y C, Liu S Q, Zhou J B
Department of AMES/Bioengineering, University of California, San Diego, La Jolla 92093-0412.
J Biomech Eng. 1993 Nov;115(4B):453-9. doi: 10.1115/1.2895523.
Changes in the mechanical properties of a blood vessel when it remodels itself under stress are reviewed. One of the recent findings about blood vessels is the rapidity of tissue remodeling when the blood pressure is changed. When the tissue structure and material composition remodel, the zero-stress state of the vessel changes. The mechanical properties change also in the remodeling process. If the elastic behavior is expressed in terms of a pseudo-elastic strain-energy function, then the constants in the function will change in the course of the remodeling. With all these changes taking place, the scope of constitutive equations broadens: it should now include a mass-and-structure growth-stress relationship as well as a stress-strain-relationship. To obtain the mass-and-structure growth-stress relationship, one must be able to determine the mechanical properties of the different layers of the vessel wall, as well as the chemical composition and morphology. For the blood vessels, new methods of mechanical testing must be introduced. A key thought is to use bending of the blood vessel wall. By bending, different layers of the vessel wall are subjected to different stresses, leading to equations that can be used to solve the inverse problem of determining the stress-strain law from measured stress and strain. In vitro and in vivo experiments and theoretical prospectives are presented.
本文综述了血管在应力作用下自我重塑时其力学性能的变化。关于血管的最新发现之一是，当血压发生变化时，组织重塑的速度很快。当组织结构和材料成分发生重塑时，血管的零应力状态会发生变化。在重塑过程中，力学性能也会改变。如果弹性行为用伪弹性应变能函数来表示，那么该函数中的常数在重塑过程中会发生变化。随着所有这些变化的发生，本构方程的范围扩大了：现在它应该包括质量与结构生长应力关系以及应力应变关系。为了获得质量与结构生长应力关系，必须能够确定血管壁不同层的力学性能以及化学成分和形态。对于血管，必须引入新的力学测试方法。一个关键思路是利用血管壁的弯曲。通过弯曲，血管壁的不同层会受到不同的应力，从而得到可用于从测量的应力和应变求解确定应力应变定律反问题的方程。文中还介绍了体外和体内实验以及理论展望。
