ELASTIC EXCITABLE MEDIUM

A type of excitable medium-an elastic excitable medium-has been create d by incorporating the Belousov-Zhabotinsky reaction into a polyacryla mide-silica gel. It permits one to address the problem of how the card iac muscle contractions affect the dynamics of rotating spiral waves. Investigations of the effects of mechanical deformations on the excita tion wave propagation exhibit a resonance dynamics of vortices. For eq ual frequencies of deformation and of vortex rotation, vortices drift. The drift velocity is about 3% of the excitation wave velocity, for a 50% elongation. The direction of the drift does not coincide with the stretching direction and can be varied by changing the phase shift be tween deformations and vortex rotation. Numerical calculations suggest that the effects of mechanical deformations on excitation wave propag ation are independent of the exact nature of the excitable medium.