Dresden 2009 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 26: Poster II

DY 26.15: Poster

Donnerstag, 26. März 2009, 16:00–18:00, P1A

Suppression of pulse propagation in excitable media through time delayed feedback — Felix M. Schneider, •Markus A. Dahlem, M. Hannelore Rittmann-Frank, and Eckehard Schöll — Institut f. Theo. Physik, Sekr. EW 7-1, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany

We propose a mechanism to suppress spatio-temporal pattern formation in excitable media based on feedback control. As a generic model for excitable media the FitzHugh-Nagumo system with diffusion in the activator variable is investigated in a one dimensional domain. We show that by applying time-delayed feedback control in this system, the propagation of traveling pulses can be suppressed. The suppression can be explained by a shift of the propagation boundary in the parameter space of the model. This boundary is a bifurcation of codimension one separating the parameter regime of pulse propagation from the regime where a local disturbance dies out. The optimization of this feedback and its characteristic time scales are discussed for different control schemes and ranges of control parameters. Moreover, we discuss a mechanism for the emergence of spreading depolarization, i.e., reaction-diffusion waves occurring under neurological conditions such as migraine and stroke, by impaired neurovascular coupling that provides a natural time-delayed feedback signal.