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Collapsible tube model for the dynamics of closure of the mitral valve

The fluid mechanics of the closure motion of a short collapsible tube segment, subject to a strong flow deceleration as in one of Henderson & Johnson's (1912) experiments, is investigated experimentally and theoretically. Physical similarity to the closure process of the mitral valve is obtained. In the study particular emphasis is placed upon the evolution of the longitudinal profiles of the collapsible tube during its closure motion. It is found that the flexible tube first closes near its upstream end and that this first phase is followed by a propagation process toward the downstream end. The characteristics of this typical sequence and of the longitudinal shape of the collapsible tube are related to hydrodynamic parameters. The results predicted by the theory agree consistently with those obtained from the experiments.