Effect of Two-Part Inhomogeneity on Spiral Wave Dynamics in Excitable Media

Inhomogeneity exists extensively in many real excitable media. In this paper, we divide the whole space into two parts by a straight line and investigate the effect of two-part inhomogeneity on dynamics of spiral wave by their tip motions. In the test simulation, let the excitable parameters of the two division spaces take different values. Numerical calculation results show that in different domains distribution each parameter region which plays a dominant role on the movement of the tip is not the same. With the approach of the location of the dividing line to the initial tip, there is three different domains distribution about it and each parameter region which plays a dominant role on the movement of the tip is not the same. Through numerical calculation, we know that along with the increase of the dividing line's location, the needed time which the tip is drew in the right region becomes a linear growth trend approximately. This is due to along with the position changes of the dividing line, the size of the domain played a major influence on the spiral motion is changing constantly. For the time being with the increasing of the dividing line location, x-axis with the center position of the wave tip pulled into the region presented a linear growth roughly. The similar law of spiral tip motion is studied under the condition of the other parameter values.