Every model. Every real recording. One bench.
An unstructured sandbox for the eight interactive tools used throughout the course. Nothing here is pre-rendered — the recordings are real microvolts and the models are integrated live in your browser.
Real EMG bench
Three real needle recordings — scroll, zoom, measure, and listen.
Healthy control: Crisp tri/biphasic MUAPs around 0.5–1 mV that recruit smoothly as effort rises.
44 y/o male · Tibialis anterior · concentric needle · No history of neuromuscular disease. Real recording · 4 kHz.
Side-by-side comparison
Healthy, myopathic, and neuropathic recordings on one screen.
Crisp tri/biphasic MUAPs around 0.5–1 mV that recruit smoothly as effort rises.
Small, short-duration, often polyphasic units; a dense (early/full) recruitment pattern at low force.
Giant, long-duration MUAPs (>3 mV) from collateral reinnervation; reduced recruitment with rapid firing.
| Feature | Healthy | Myopathic | Neuropathic |
|---|---|---|---|
| MUAP amplitude | Normal (0.5–1 mV) | Low (small units) | High (giant units) |
| MUAP duration | Normal | Short | Long |
| Recruitment | Normal | Early / full | Reduced |
| Firing rate at low force | Low | Low (many units) | High (few units) |
| Polyphasia | <15% | Increased | Increased |
Action potential (Hodgkin–Huxley)
Inject current and watch the conductances drive an all-or-none spike.
Motor unit recruitment
Drive effort; compare normal, neurogenic, and myopathic patterns.
Orderly small-to-large recruitment with balanced rate coding — a normal interference pattern.
Nerve conduction lab
Measure latency and conduction velocity with draggable calipers.
Drag calipers A and B onto the two onsets to measure conduction velocity across the forearm segment.
Repetitive nerve stimulation
Produce the decrement of myasthenia and the increment of LEMS.
Postsynaptic block (too few ACh receptors): the normal run-down of ACh release at 3 Hz drops some endplates below threshold → decrement, worst at the 4th–5th response.
Filter bench
Distort a real recording with high-pass, low-pass, and notch filters.
Raise the high-pass filter and the slow components of each potential vanish — amplitude falls and the waveform narrows, which can shorten apparent duration. Lower the low-pass filter and fast spikes are rounded off, reducing amplitude and adding latency. The 60 Hz notch removes line noise but carves a hole in the physiologic signal that lives there too.
Waveform challenge
Classify blinded real recordings and test the framework.
Blinded real recording — classify the pattern.
Real recording · 1 mV/div · 100 ms/div · identity hidden.