Kinematical Description of Meandering Spiral Waves in Active Media

Under certain conditions the dynamics of spiral waves in active media can be described within a kinematical approach. We discuss the importance of curvature effects for the transition from rigidly rotating to outward meandering spirals. To include these effects into the kinematical description we propose a modified boundary condition for the curvature at the tip. This allows to recover a variety of rotation regimes with hypocycloid-like trajectories of the spiral tip corresponding to outward meandering spiral waves which are frequently observed experimentally in active media of quite different nature beyond the instability of rigid rotation.