FitzHugh-Nagumo excitable media · 2D tissue · Spiral wave reentry
Click anywhere on tissue to stimulate
Membrane potential v ∈ [−2, 2]
A 2D excitable-media simulation of cardiac tissue using the FitzHugh–Nagumo model. Click to stimulate regions and watch action potential waves, spiral reentry and fibrillation emerge from a simple two-variable ODE.
How excitable cells (cardiomyocytes) generate and propagate electrical impulses. The FitzHugh–Nagumo model captures depolarisation, repolarisation and the refractory period with just two variables — a fast voltage-like variable and a slow recovery variable.
Click anywhere on the tissue grid to deliver a stimulus. Place a second stimulus during the refractory tail to trigger spiral reentry — the mechanism behind cardiac arrhythmias. Adjust diffusion and time constants to control wave speed.
Spiral reentry waves in the heart are a leading cause of ventricular tachycardia and fibrillation. Defibrillation works by simultaneously depolarising all cells, resetting the tissue so the normal pacemaker (SA node) can regain control.