A Non-invasive Method of Tracing Spiral Tips

A new method is developed to trace the tip of spiral waves in an excitable medium. The information of a spiral tip movement is obtained from only six probes. This method can trace the tip of a simple rotating spiral as well as a complex spiral tip movement. More importantly, it can be used to distinguish between a spiral and a target wave. The method is checked with data by experiments and numerical simulations, and found to be successful.