Interactions of spiral waves in inhomogeneous excitable media

✍ Scribed by Michael Vinson

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 816 KB
• Volume: 116
• Category: Article
• ISSN: 0167-2789
• DOI: 10.1016/s0167-2789(97)00256-x

✦ Synopsis

This paper examines the behavior of pairs of spiral waves in a two-dimensional excitable medium with a parameter gradient, and extends the results to study the effects of self-interactions of scroll waves in three dimensions. When two spirals are placed in regions of different local rotation periods, the interaction between the waves significantly affects their motion. There are two distinct phases of the interaction: initially, the spiral with faster rotation period "unwinds" the slower one. After the unwinding, the wavefronts from the faster spiral interact directly with the center of rotation (core) of the slower one, producing a drift that is significantly faster than that due to the gradient alone. A simple point-source model yields a prediction of the unwinding time, and the motion after unwinding can be understood in terms of planar wavefronts interacting with the core of the slower spiral. The results are then applied to self-interactions of a scroll ring in three dimensions, where they suggest that nonlocal effects are significant when a parameter gradient is present.