This applet shows the voltage produced by a cell using the FHN model as a
function of time after it is stimulated above its threshold.
The start button initiates the simulation and the reset button brings back the parameters to the initial values.
The model parameters can be changed by editing their respective fields and pressing
For example, by changing delta to 0.03 or larger one can change the system from excitable to auto-oscillatory.
By increasing epsilon the APD decreases and vise versa ( try 0.05 and 0.001).
The FHN model can be found in: Biophys. J. Vol 1 445-466, 1961 by R. FitzHugh see also Physica D Vol 41 p173 1990, by M. Courtemanche and W. Skaggs and A.T. Winfree