Control of Spatiotemporal Turbulence in Oscillatory and Excitable Media

Spatiotemporal turbulence or defect-mediated turbulence exists quite generally in excitable and oscillatory media such as chemical turbulence in reaction-diffusion systems and electrical turbulence in cardiac muscle. In many situations spatiotemporal turbulence is very undesirable. For example, ventricular fibrillation, the major reason behind sudden cardiac death, is a turbulent cardiac electrical activity in which rapid and irregular disturbances make the heart incapable of executing a concerted pumping action. Therefore, the suppression of spatiotemporal turbulence is of much practical importance.2–4 Recently, Aranson et al. suggested a method of spatiotemporal turbulence control in the complex Ginzburg–Landau equation and in an excitable medium by developing a spiral wave with a local feedback injection. Using low pulses over a coarse mesh of lines, Sinha et al. achieved the control of spatiotemporal turbulence (defibrillation) in a model for cardiac muscle. Experimentally, Kim et al. successfully controlled chemical turbulence in catalytic CO oxidation on Pt(110) by a global delayed feedback. In this paper, we will study the suppression of spatiotemporal turbulence in oscillatory and excitable media by applying a periodic forcing at a single point. Spiral waves or target waves are generated and they suppress turbulence.