Watanabe Hiroshi, Sugiura Seiryo, Kafuku Hidenobu, Hisada Toshiaki
Computational Biomechanics Division, Institute of Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
Biophys J. 2004 Sep;87(3):2074-85. doi: 10.1529/biophysj.103.035840.
To relate the subcellular molecular events to organ level physiology in heart, we have developed a three-dimensional finite-element-based simulation program incorporating the cellular mechanisms of excitation-contraction coupling and its propagation, and simulated the fluid-structure interaction involved in the contraction and relaxation of the human left ventricle. The FitzHugh-Nagumo model and four-state model representing the cross-bridge kinetics were adopted for cellular model. Both ventricular wall and blood in the cavity were modeled by finite element mesh. An arbitrary Lagrangian Eulerian finite element method with automatic mesh updating has been formulated for large domain changes, and a strong coupling strategy has been taken. Using electrical analog of pulmonary circulation and left atrium as a preload and the windkessel model as an afterload, dynamics of ventricular filling as well as ejection was simulated. We successfully reproduced the biphasic filling flow consisting of early rapid filling and atrial contraction similar to that reported in clinical observation. Furthermore, fluid-structure analysis enabled us to analyze the wave propagation velocity of filling flow. This simulator can be a powerful tool for establishing a link between molecular abnormality and the clinical disorder at the macroscopic level.
为了将亚细胞分子事件与心脏的器官水平生理学联系起来，我们开发了一个基于三维有限元的模拟程序，该程序纳入了兴奋 - 收缩偶联及其传播的细胞机制，并模拟了人类左心室收缩和舒张过程中涉及的流固相互作用。细胞模型采用了代表横桥动力学的菲茨休 - 纳古莫模型和四态模型。心室壁和腔内血液均采用有限元网格进行建模。针对大域变化制定了具有自动网格更新的任意拉格朗日欧拉有限元方法，并采用了强耦合策略。使用肺循环和左心房的电模拟作为前负荷，以及风箱模型作为后负荷，模拟了心室充盈和射血的动力学过程。我们成功地再现了由早期快速充盈和心房收缩组成的双相充盈流，类似于临床观察中报道的情况。此外，流固分析使我们能够分析充盈流的波传播速度。该模拟器可以成为在宏观层面建立分子异常与临床疾病之间联系的有力工具。
