Rotating spiral patterns in the Barkley model of excitable media — found in cardiac tissue and the BZ reaction
Spirals form when a wavefront breaks — the free end curls back and rotates. In cardiac tissue, spiral waves can cause ventricular tachycardia.
Barkley (1991) model:
∂u/∂t = (1/ε)u(1−u)(u−(v+b)/a) + ∇²u
∂v/∂t = u − v
The tip traces an epicycloid or circular orbit depending on parameters. Click to add a new spiral seed.