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For Engineers · Cardiac Rhythm

Cardiac Rhythm for a circadian rhythm

Built for engineers using it for real design work. Go from concept to a running model in the browser, then scale to the cloud when needed. Simulate a circadian rhythm live below — adjust the inputs and watch it respond, right in your browser.

Neuron

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Hodgkin-Huxley NeuronLive

the action potential

Controls

Speed1×

Presets

Injected current (µA/cm²)

The Hodgkin-Huxley model — the Nobel-winning description of the nerve impulse — tracks voltage and the opening of sodium and potassium channels. Below a threshold current the neuron is silent; above it, it fires a train of action potentials whose rate climbs with the stimulus.

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Data Inspector

Firing rate0.0 Hz

Regimespiking

ChannelsNa⁺ / K⁺

Governing equation

C_{m} \frac{d V}{d t} = 10 - \overset{g}{ˉ}_{N a} m^{3} h (V - E_{N a}) - \overset{g}{ˉ}_{K} n^{4} (V - E_{K}) - \overset{g}{ˉ}_{L} (V - E_{L})

Reading this result: Above threshold: each stimulus recharges the membrane fast enough to re-trigger Na⁺ channels, so the neuron fires a repetitive train whose rate rises with the current.

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Frequently asked questions

Is this good for engineers?: Yes — this version of "Cardiac Rhythm for a circadian rhythm" is framed for engineers using it for real design work. Go from concept to a running model in the browser, then scale to the cloud when needed.
Do I need to install anything?: No. It runs in any modern browser, free, with no account required.