Rocsoreanu / Georgescu / Giurgiteanu The FitzHugh-Nagumo Model

Bifurcation and Dynamics
2000
ISBN: 978-94-015-9548-3
Verlag: Springer Netherland
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, Band 10, 238 Seiten, eBook

Reihe: Mathematical Modelling: Theory and Applications

The present monograph analyses the FitzHugh-Nagumo (F-N) model Le. , the Cauchy problem for some generalized Van der Pol equation depending on three real parameters a, band c. This model, given in (1. 1. 17), governs the initiation of the cardiac impulse. The presence of the three parameters leads to a large variety of dy namics, each of them responsible for a specific functioning of the heart. For physiologists it is highly desirable to have aglobai view of all possible qualitatively distinct responses of the F-N model for all values of the pa rameters. This reduces to the knowledge of the global bifurcation diagram. So far, only a few partial results appeared and they were spread through out the literature. Our work provides a more or less complete theoretical and numerical investigation of the complex phase dynamics and bifurca tions associated with the F-N dynamical system. This study includes the static and dynamic bifurcations generated by the variation of a, band c and the corresponding oscillations, of special interest for applications. It enables one to predict all possible types of initiations of heart beats and the mechanism of transformation of some types of oscillations into others by following the dynamics along transient phase space trajectories. Of course, all these results hold for the F-N model. The global phase space picture enables one to determine the domain of validity of this model.

Zielgruppe

Research

Autoren/Hrsg.

Rocsoreanu, C.

Georgescu, A.

Giurgiteanu, N.

Inhaltsverzeichnis

1 Models and Dynamics.- 1.1 Models of the Heart Functioning.- 1.2 Elements of Finite-Dimensional Dynamics.- 1.3 Bifurcation.- 1.4 Regular and Singular Perturbations.- 2 Static Bifurcation and Linearization of the FitzHugh-Nagumo Model.- 2.1 Geometric Properties of Phase Trajectories.- 2.2 Equilibria.- 2.3 Eigenvalues of the Linearized System. Eigenvectors and Eigen-Directions.- 2.4 Static Bifurcation Diagrams: Partial Dynamical Characterization.- 2.5 Asymptotic Behaviour of the Static Bifurcation Diagrams as c ? ?.- 2.6 Types of Hyperbolic Equilibria.- 2.7 The Center Manifold and the Saddle-Node Bifurcation.- 3 Dynamic Bifurcation for the FitzHugh-Nagumo Model.- 3.1 Hopf Bifurcation.- 3.2 Bogdanov-Takens Bifurcation.- 3.3 Homoclinic Bifurcation.- 3.4 Breaking Saddle Connection Bifurcation.- 3.5 Bautin Bifurcation. Non-Hyperbolic Limit Cycle Bifurcation.- 4 Models of Asymptotic Approximation for the FitzHugh-Nagumo System as c ? ?.- 4.1 Types of Asymptotic Behaviour of the Solution of the F-N Model.- 4.2 First Order Asymptotic Approximations as ? ? 0.- 4.3 Higher Order Asymptotic Approximations as ? ? 0.- 4.4 Some Particular Cases.- 4.5 Asymptotic Results on Ducks (French Canards) and Related Objects.- 5 Global Bifurcation Diagram and Phase Dynamics for the FitzHugh-Nagumo Model.- 5.1 Global Bifurcation Diagram for the FitzHugh-Nagumo Model.- 5.2 Basins of Attraction.- 5.3 Transient Regimes and Non-Periodic Oscillations.- 5.4 Limit Cycles and Periodic Oscillations.- 5.5 The Initiation of Heart Beats.- 5.6 Concluding Remarks of Interest to Physiologists.- 5.7 Open Mathematical Problems.- A Liapunov Coefficients.- B Brief Description of the Soft Diecbi.- References.