Suppression of Spiral Breakup in Excitable Media by Local Periodic Forcing

2016 ◽  
Vol 26 (14) ◽  
pp. 1650236
Author(s):  
Guiquan Liu ◽  
Heping Ying ◽  
Honglei Luo ◽  
Xiaoxia Liu ◽  
Jinghua Yang
Keyword(s):  
Ventricular Fibrillation ◽  
Numerical Simulations ◽  
Phase Diagrams ◽  
Cardiac Arrhythmia ◽  
Underlying Mechanism ◽  
Spiral Waves ◽  
Low Energy ◽  
Excitable Media ◽  
Periodic Forcing ◽  
Cardiac Tissues

Lowered excitability leads to unstable meandering of spiral tip, which result in breakup of spiral waves into chaotic states induced by Doppler effects. This phenomenon is responsible for the transition from tachycardia to ventricular fibrillation in cardiac tissues. Numerical simulations show that low-energy local periodic forcing (LPF) applied around spiral tip can efficiently suppress the meandering behavior and consequently prevent spiral breakup. The controllable phase diagrams that describe the amplitude and period of LPF against excitability parameter are presented to illustrate the control region. The underlying mechanism of suppressing spiral meandering behavior is explored by greatly decreasing the radius of the meandering tip. The proposed scheme can potentially contribute to controlling cardiac arrhythmia.

THREE-DIMENSIONAL ASPECTS OF RE-ENTRY IN EXPERIMENTAL AND NUMERICAL MODELS OF VENTRICULAR FIBRILLATION

1999 ◽  
Vol 09 (04) ◽  
pp. 695-704 ◽  
Author(s):  
V. N. BIKTASHEV ◽  
A. V. HOLDEN ◽  
S. F. MIRONOV ◽  
A. M. PERTSOV ◽  
A. V. ZAITSEV
Keyword(s):  
Ventricular Fibrillation ◽  
Numerical Simulations ◽  
Numerical Models ◽  
Three Dimensional ◽  
Spiral Waves ◽  
Excitable Media ◽  
Ventricular Wall ◽  
Two Dimensional ◽  
Key Features ◽  
Scroll Waves

Ventricular fibrillation is believed to be produced by the breakdown of re-entrant propagation waves of excitation into multiple re-entrant sources. These re-entrant waves may be idealized as spiral waves in two-dimensional, and scroll waves in three-dimensional excitable media. Optically monitored, simultaneously recorded endocardial and epicardial patterns of activation on the ventricular wall do not always show spiral waves. We show that numerical simulations, even with a simple homogeneous excitable medium, can reproduce the key features of the simultaneous endo- and epicardial visualizations of propagating activity, and so these recordings may be interpreted in terms of scroll waves within the ventricular wall.

Spiral waves in excitable media due to noise and periodic forcing

2011 ◽  
Vol 44 (9) ◽  
pp. 728-738 ◽  
Author(s):  
Guoyong Yuan ◽  
Lin Xu ◽  
Aiguo Xu ◽  
Guangrui Wang ◽  
Shiping Yang
Keyword(s):  
Spiral Waves ◽  
Excitable Media ◽  
Periodic Forcing

scholarly journals Dynamics of spiral waves and bubble formation in a closed chemical system of thin photosensitive excitable media

2021 ◽  
Vol 2145 (1) ◽  
pp. 012025
Author(s):  
Kritsana Khaothong ◽  
Vikanda Chanchang ◽  
Jarin Kanchanawarin ◽  
Malee Sutthiopad ◽  
Chaiya Luengviriya
Keyword(s):  
Thin Layer ◽  
Bubble Formation ◽  
Three Dimensional ◽  
Spiral Waves ◽  
Excitable Media ◽  
Chemical System ◽  
Layer System ◽  
Cardiac Tissues ◽  
Bz Reaction ◽  
Life Threatening

Abstract Spiral waves have been observed in a thin layer of excitable media. Especially, electrical spiral waves in cardiac tissues connect to cardiac tachycardia and life-threatening fibrillations. The Belousov-Zhabotinsky (BZ) reaction is the most widely used system to study the dynamics of spiral waves in experiments. When the light sensitive Ru(bpy)3 2+ is used as the catalyst, the BZ reaction becomes photosensitive and the excitability of the reaction can be controlled by varying the illumination intensity. However, the typical photosensitive BZ reaction produces many CO2 bubbles so the spiral waves are always studied in thin layer media with opened top surfaces to release the bubbles. In this work, we develop new chemical recipes of the photosensitive BZ reaction which produces less bubbles. To observe the production of bubbles, we investigate the dynamics of spiral waves in a closed thin layer system. The results show that both the speed of spiral waves and the number of bubbles increase with the concentration of sulfuric acid (H2SO4) and sodium bromate (NaBrO3). For high initial concentrations of both reactants, the size of bubbles increases with time until the wave structures are destroyed. We expect that the chemical recipes reported here can be used to study complicated dynamics of three-dimensional spiral waves in thick BZ media where the bubbles cannot escape.

Dynamics of spiral waves in excitable media subjected to external periodic forcing

1995 ◽  
Vol 52 (1) ◽  
pp. 98-108 ◽  
Author(s):  
A. Schrader ◽  
M. Braune ◽  
H. Engel
Keyword(s):  
Spiral Waves ◽  
Excitable Media ◽  
Periodic Forcing

Periodic forcing of spiral waves in excitable media

1996 ◽  
Vol 54 (5) ◽  
pp. 4791-4802 ◽  
Author(s):  
Rolf-Martin Mantel ◽  
Dwight Barkley
Keyword(s):  
Spiral Waves ◽  
Excitable Media ◽  
Periodic Forcing

SUPPRESSING SPIRAL WAVES IN EXCITABLE MEDIA VIA UNIDIRECTIONAL COUPLING

2008 ◽  
Vol 22 (24) ◽  
pp. 4153-4161 ◽  
Author(s):  
YU QIAN ◽  
YU XUE ◽  
GUANG-ZHI CHEN
Keyword(s):  
Co Oxidation ◽  
Power Law ◽  
Coupling Strength ◽  
Control Method ◽  
Spiral Waves ◽  
Coupling Method ◽  
Excitable Media ◽  
Catalytic Co Oxidation ◽  
Unidirectional Coupling ◽  
High Control

A unidirectional coupling method to successfully suppress spiral waves in excitable media is proposed. It is shown that this control method has high control efficiency and is robust. It adapts to control of spiral waves for catalytic CO oxidation on platinum as well as for the FHN model. The power law n ~ c-k of control time steps n versus the coupling strength c for different models has been obtained.

Electrokinetic instability due to streamwise conductivity gradients in microchip electrophoresis

2021 ◽  
Vol 925 ◽  
Author(s):  
Kaushlendra Dubey ◽  
Sanjeev Sanghi ◽  
Amit Gupta ◽  
Supreet Singh Bahga
Keyword(s):  
Electric Field ◽  
Numerical Simulations ◽  
Electric Fields ◽  
Quantitative Measure ◽  
Underlying Mechanism ◽  
Scaling Analysis ◽  
Recirculating Flow ◽  
Electrokinetic Instability ◽  
Spatial Features ◽  
Proper Orthogonal Decomposition Technique

We present an experimental and numerical investigation of electrokinetic instability (EKI) in microchannel flow with streamwise conductivity gradients, such as those observed during sample stacking in capillary electrophoresis. A plug of a low-conductivity electrolyte solution is initially sandwiched between two high-conductivity zones in a microchannel. This spatial conductivity gradient is subjected to an external electric field applied along the microchannel axis, and for sufficiently strong electric fields an instability sets in. We have explored the physics of this EKI through experiments and numerical simulations, and supplemented the results using scaling analysis. We performed EKI experiments at different electric field values and visualised the flow using a passive fluorescent tracer. The experimental data were analysed using the proper orthogonal decomposition technique to obtain a quantitative measure of the threshold electric field for the onset of instability, along with the corresponding coherent structures. To elucidate the physical mechanism underlying the instability, we performed high-resolution numerical simulations of ion transport coupled with fluid flow driven by the electric body force. Simulations reveal that the non-uniform electroosmotic flow due to axially varying conductivity field causes a recirculating flow within the low-conductivity region, and creates a new configuration wherein the local conductivity gradients are orthogonal to the applied electric field. This configuration leads to EKI above a threshold electric field. The spatial features of the instability predicted by the simulations and the threshold electric field are in good agreement with the experimental observations and provide useful insight into the underlying mechanism of instability.

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