Unpinning the spiral waves by using parameter waves

The spiral waves anchored to heterogeneous areas are more difficult to control and eliminate than freely rotating ones in homogenous mediums.To eliminate pinned spiral waves,the resistant force should be provided to resist the pinning force.Other than advection field,we introduce parametric wave to play the role of providing resistant force.It is found that the parametric wave with large enough amplitude and proper frequency can unpin and eliminate the spiral wave successfully.The capability of parametric wave in providing resistant force is dependent on its amplitude and frequency sensitively.On the basis of parametric wave,the dependence of pinning force on the size and level of heterogeneity is further confirmed.