Fast Selective Elimination of Spiral Waves

Abstract

Elimination of spiral waves prevents transition to chaotic state in excitable media of different physicochemical nature. In cardiac muscle, to prevent cardiac death, the spiral waves are usually removed together with all propagating waves by a strong electric shock: 5 kV, 20 A ("defibrillation"). We have found an approach to extinguish spiral waves without destroying normally propagating waves. Chemical excitation waves in a spatial open reactor with the Belousov-Zhabotinsky reaction controlled by light were used as an experimental model. We found three different scenarios, depending on the rate of the light change. (i) When the light intensity was increased immediately, the spiral wave was eliminated. (ii) When it was increased slowly enough, the spiral wave survived, increasing its core and diminishing its rotation rate. (iii) When it was increased gradually, at an intermediate rate, the spiral wave survived, but multiple wave breaks appeared at the periphery. Computer modeling has shown that the results obtained are generic and relevant for excitable media of various nature.

Surfactant-induced gradients in the three-dimensional Belousov-Zhabotinsky reaction

“…One possibility is to replace malonic acid by 1,4-cyclohexanedione, which does not form CO 2 during the BZ reaction [27,28]. In the classical BZ system, a popular technique consists in the addition of small amounts of the surfactant sodium dodecyl sulfate (SDS) to the BZ reaction medium [9,[29][30][31][32][33]. It is generally assumed that, when added at concentrations below its critical micelle concentration (CMC), SDS does not affect the dynamics of the BZ system [29,31].…”

Photosensitive, Bubble-free, Bromate−1,4-Cyclohexanedione Oscillating Reactions. Illumination Control of Pattern Formation

“…Photosensitivity offers a very convenient way to control formation and dynamics of spatiotemporal chemical patterns. So far, the Ru(bpy) 3 -catalyzed Belousov−Zhabotinsky (BZ) reaction−diffusion system with malonic acid as the initial reductant has been employed almost exclusively for creation of chemical patterns and control of the chemical wave propagation. − An important drawback of this reaction is the production of carbon dioxide, which results in the formation of bubbles that disturb the reaction−diffusion patterns and makes it difficult to conduct lengthy experiments.…”