FitzHugh-Nagumo model in a 2D sheet
This applet implements the FitzHugh-Nagumo model in two dimensions.
To use the applet, click on the Start button to initiate a plane wave from the left.
To initiate a spiral wave, click on Reset h (reset half plane) when
the plane wave is in the middle of the tissue. This will break the
wave front to initiate the spiral wave.
Some buttons are not functional yet, such as R IC (read
initial conditions), W IC (write initial conditions),
Tip off/on (finds and plots the tip trajectory of any
spiral) and Periodic Boundary Conditions (for periodicity along
one of the axes).
Things to try:
Record the signal at a given point in the tissue.
Press the
Trace
button in the lower right
and then click in the main plot to select the location
from which to record. Use the check boxes to indicate
whether ( Voltage,
v-gate or both should be recorded.
When you click on a new position in the tissue, the recording
automatically switches to
that location.
Stimulate the tissue directly. Click on
the S1 button
(its text will change to S1 on ) and set
the size of the stimulus in the box below.
Click anywhere in the tissue to
introduce a stimulus at that location.
Repeat as desired to form conduction blocks and multiple waves.
Use an extremely large stimulus to "defibrillate" the tissue.
Visualize either the Voltage field or
v-gate field in 2D by using the radio buttons.
Change the color map using the drop-down list box.
Change the model's parameter values.
Change the tissue size (lowest box on the right). The
size can vary between 50 and 200
units and the tissue is always a square (enter a number and retun).
(Experts only!) Change the integration dt and dx for the model
as you change the parameters.
Note that if you these values are too large
you may crash the program.
For more information see
the single cell FHN model applet .