Wuyts F L, Vanhuyse V J, Langewouters G J, Decraemer W F, Raman E R, Buyle S
University of Antwerp, RUCA, Laboratory for Biomedical Physics, Belgium.
Phys Med Biol. 1995 Oct;40(10):1577-97. doi: 10.1088/0031-9155/40/10/002.
A new structural model is described for the tension-radius relationship of blood vessels, taking into account their mechanically important constituents: collagen, elastin and smooth muscle. The model has four characteristic parameters: EC, the Young's modulus of the collagen fibres; ESE, the Young's modulus of the combined smooth-muscle/elastin network; epsilon mu, the amount of strain at which the high stiffness region on the tension-radius curve is reached, and eta an indicator for the degree of collagen fibre stretching. The structural stiffness of the wall constituents is reflected by EC and ESE whereas the global stiffness of the entire blood vessel is described by epsilon mu and eta. All these elasticity parameters are pressure independent, in contrast to generally quoted values for the incremental modulus or vascular compliance which are strongly pressure dependent. Hence, an objective comparison of the mechanical properties for various types of blood vessel, based on the present model parameters, has been made possible. The model was successfully fitted to tension-radius data of 65 human aortas, age range 30-88 years, with moderate or severe atherosclerosis. The structural as well as the global stiffness changes with age, e.g. collagen stiffness shows a ninefold increase over 60 years. Global stiffness depends on atherosclerosis.
本文描述了一种新的血管张力-半径关系结构模型，该模型考虑了血管中具有重要力学意义的成分：胶原蛋白、弹性蛋白和平滑肌。该模型有四个特征参数：EC，即胶原纤维的杨氏模量；ESE，即平滑肌/弹性蛋白复合网络的杨氏模量；εμ，即张力-半径曲线上达到高刚度区域时的应变值；以及η，即胶原纤维拉伸程度的指标。壁成分的结构刚度由EC和ESE反映，而整个血管的整体刚度由εμ和η描述。与通常引用的增量模量或血管顺应性值强烈依赖压力不同，所有这些弹性参数均与压力无关。因此，基于当前模型参数，对各种类型血管的力学性能进行客观比较成为可能。该模型成功拟合了65例年龄在30-88岁之间、患有中度或重度动脉粥样硬化的人类主动脉的张力-半径数据。结构刚度和整体刚度均随年龄变化，例如，胶原刚度在60年内增加了九倍。整体刚度取决于动脉粥样硬化。
