Computational mechanics of the heart - From tissue structure to ventricular function
Computational mechanics of the heart - From tissue structure to ventricular function
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DOI：
10.1023/a:1011084330767
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发表时间：
2000-01-01
影响因子：
2
通讯作者：
Hunter, PJ
中科院分区：
文献类型：
--
作者：
Nash, MP;Hunter, PJ
有限弹性理论与有限元分析相结合，为分析心脏周期充盈阶段的室壁力学提供了框架，此时心肌细胞没有主动收缩。被动组织的正交各向异性特性在这里由“极-零”本构定律描述，其参数部分来源于胶原纤维的基本分布模型。这些分布是基于我们对心肌组织纤维板结构的观察。我们举例说明了高阶(三次Hermite)基函数在求解基于该正交各向异性本构关系的Galerkin有限元应力平衡方程中的应用，并考虑了观察到的纤维和板材取向的区域分布。将模型预测的压力-体积关系和三维主应变与实验观测结果进行了比较。为了预测心脏周期收缩末期3D主应变的跨壁分布，还引入了一个基于分离肌肉实验的活跃组织特性模型。最后，我们对当前的心室力学模型提出了批评，并对未来的模型师提出了新的挑战。
Finite elasticity theory combined with finite element analysis provides the framework for analysing ventricular mechanics during the filling phase of the cardiac cycle, when cardiac cells are not actively contracting. The orthotropic properties of the passive tissue are described here by a "pole-zero" constitutive law, whose parameters are derived in part from a model of the underlying distributions of collagen fibres. These distributions are based on our observations of the fibrous-sheet laminar architecture of myocardial tissue. We illustrate the use of high order (cubic Hermite) basis functions in solving the Galerkin finite element stress equilibrium equations based on this orthotropic constitutive law and for incorporating the observed regional distributions of fibre and sheet orientations. Pressure-volume relations and 3D principal strains predicted by the model are compared with experimental observations. A model of active tissue properties, based on isolated muscle experiments, is also introduced in order to predict transmural distributions of 3D principal strains at the end of the contraction phase of the cardiac cycle. We end by offering a critique of the current model of ventricular mechanics and propose new challenges for future modellers.