Java visualisation of the FitzHugh-Nagumo model
The FitzHugh-Nagumo model is a prototype model of an excitable, non-linear system (e.g. a neuron). The system is usually in the fixed point, but may leave it for an excursion in the phase space. This excursion can be triggered externally (manually), by a second (coupled) system or by random noise.
This applet displays the dynamics of two such systems by plotting xt (time series) and xy (phase space) diagrams. Both systems can be connected to each other by a coupling constant C (default C=0). One may also switch on self-feedback via the parameter K. Both couplings may be applied with a time delay tau.
Besides adjusting parameters with their corresponding sliders, one can also influence the dynamics by using a set of buttons.
- Exciting Pulse adds a predefined value (see Stim Size) to the parameter u1
- Reset System 1 to Fixed Point forces u1 and v1 to their fixed point values
- Noise Options opens a dialogue in which one can adjust the noise amplitudes of v1 and v2.
More available options:
- Show Eqs. displays the equations being solved numerically (same as above)
- Save.. opens a file dialogue, which allows saving the current data. Note: The data saved is 20 times more accurately sampled than the data plotted.
- Clear Phase Portraits erases the previous plot points in the phase portraits.
- Show Full Time Scale blocks automatic scrolling of the xt diagrams.
- FitzHugh-Nagumo-System (Scholarpedia)