A MODEL OF THE LEFT VENTRICLE: FROM THE MECHANISMS OF CONTRACTION TO HEMODYNAMICS

摘要

Wepresentamodel of the mammalian cardiac left ventricle starting from the mechanisms of muscular contraction and developing th model presented in previous publicaticns. The model, built from a thecretical proposal for the energy equation of chemo-mechanical transduction (represented bya double-port capacitor), proposes a coherent way to pass from the chemical aspect ofthe process, to the mechanical one. Is thus able toshow different energypaths and conversions, going from the molecular aspects of muscular contraction, to the representation of the geometry of th left ventricular chamber. The goal of this work is to obtain a left ventricular model with a strong physiological basis but which, in contrast with other existing models, may be understood in physical terms while being simulated sufficierntly fast to allow its integration in a whole loop model for studies of cardiac transients and teachning demonstrations. From the bond graph viewpoint, this model demonstrates the use of chemo-mechanical transducers, the approximation of chemical kinetics described by partial differential equations and the finite difference approximation of active, time-varying phenomena. All these nonclassical features may suggest possible ideas for approaching similar phenomena by bond graphs in other applications.