Unidirectional mechanism for reentrant activity generation in excitable media

A closed excitable pathway with one point-to-point connection is used to generate a rotating wave both in experiments using the photosensitive Belousov-Zhabotinsky system and numerically with an Oregonator reaction-diffusion model. By varying the excitability and geometrical properties of the medium, propagation can be made unidirectional or bidirectional, giving rise, respectively, to the existence or not of sustained reentrant activity in a closed excitable track