Switch modality, walk the 7-step workflow, and change live settings to see the traces and readouts respond.
How to use it: the row of pills selects the modality (SSEP, MEP, EMG, EEG, TOF, D-wave, BAEP, VEP). The numbered tabs are the workflow steps. The right-hand panel holds that modality's editable settings — drag a slider or change a dropdown and watch the trace, the metric badge, and the status bar update. Each modality also carries its own alarm rule on step 7.
Try the case scenario: open step 6 · Monitor and press Run random case. One of several events develops on the active modality's trace — but not all are injuries: some are anesthetic, physiologic, or technical confounders. When the trace changes, decide the cause and pick an action (alert surgeon · check anesthesia/BP/temp · check electrodes · hold & observe). Only the correct action recovers the signal; alerting the surgeon for an artifact is a false alarm. Each case ends with a debrief (what it was, the right action, a teaching point) and a running session score.
The simulator's parameter ranges, defaults and alarm rules are set to the values below. The trace physics are simplified for teaching, but the numbers and directions are drawn from these guidelines and primary sources.
| Modality | Published standard (reference) | Alarm criterion | Source |
|---|---|---|---|
| SSEP | Constant-current, pulse width 100–300 µs, rate 2–8 /s (up to ~20 /s), intensity to motor threshold; record cortical (CPc/CPi/CPz–Fz), cervical (C5S), Erb's, popliteal, T12; impedance <5 kΩ. | ≥50% amplitude drop and/or ≥10% latency increase | ACNS 11B; ASNM SEP 2024 |
| MEP | Transcranial electric; train of 5–7 pulses, ISI 1–4 ms (~4 ms = lowest threshold), pulse duration 0.05–0.5 ms (0.5 ms strongest effect); record muscle CMAP. | All-or-none CMAP loss (amplitude/threshold criteria per protocol) | ASNM MEP (Macdonald 2013); Szelényi 2007 |
| EMG | Free-run (neurotonic discharge) + triggered. Pedicle-screw thresholds: <8 mA breach concern (Calancie ~7 mA; <10 mA ≈90% breach), 10–15 mA explore, >15 mA reassuring. | Sustained neurotonic / train activity; low triggered threshold | Calancie 1994; ISIN/ASNM |
| EEG | 10–20 system, ≥8 channels (full 21 encouraged); high-pass 0.5–1 Hz, low-pass 30–70 Hz, sensitivity ~5–10 µV/mm, 15–30 mm/s; referential or bipolar. | Asymmetry / attenuation / burst-suppression vs baseline | ASNM raw-EEG/qEEG guideline |
| TOF | 4 supramaximal stimuli @ 2 Hz. 4 equal twitches to ~70% receptor occupancy; fade >70%; T4 lost ~80%, all lost >90–95%. Ratio = T4/T1 (only with 4 twitches); fade visible <0.4. MEP/EMG need ≥2–4 twitches. | Guides relaxant depth (not an injury alarm) | Naguib 2017; OpenAnesthesia |
| D-wave | Transcranial stim, epidural recording (rostral + caudal to lesion); few averages (robust signal); peak-to-peak amplitude. | ≥50% amplitude drop (IMSCT; 30–40% peri-Rolandic) | ASNM MEP; D-wave reviews (Medicina 2024) |
| BAEP | Monaural clicks 65–70 dB nHL (≈115–120 dB peSPL), rate 5–12 /s, condensation/rarefaction/alternating; record Cz–A1/A2, mask non-test ear; average 1000–2000. Waves I (~1.5 ms), III (~3.7), V (~5.7). | ≥1 ms wave V latency increase and/or ≥50% wave V amplitude drop | ACNS 9C/11C; Sindou (MVD warning values) |
| VEP | Red LED-goggle flash, ~1 /s, per eye; record Oz/O1/O2 vs linked ears; ERG confirms retinal stimulation; band-pass ~5–100 Hz, average 100–200, 500 ms window. Peaks N75 / P100 / N135. | ≥50% N75–P100 amplitude drop (high anesthetic variability) | Kodama/Sasaki flash-VEP series (2017) |
Sources: ACNS Guideline 11B (SSEP) · ASNM SEP position statement (2024) · ASNM MEP position statement (Macdonald 2013) · Szelényi 2007 — TES parameters · Triggered EMG meta-analysis (J Neurosurg Spine 2016) · ASNM raw-EEG/qEEG guideline · Naguib 2017 — neuromuscular monitoring · D-wave monitoring review (Medicina 2024) · ACNS Guideline 9C (BAEP) · Intraoperative flash VEP under GA (2017) · Cadwell Cascade Surgical Studio
Named-case references: TAAA — spinal-cord ischemia, MEP/SSEP & CSF drainage · Vestibular schwannoma — intra-op BAEP & hearing preservation · Motor-eloquent glioma — intra-op MEP mapping & monitoring · Aneurysm clipping — multimodal IONM protocol · Microvascular decompression — BAEP warning values