IONM OR Simulator

1Your first five minutes

If you do nothing else, do this. It gets you from a cold screen to a completed case.

1. The console opens already monitoring, with SSEP, MEP, EMG, EEG and train-of-four running on a stable patient. Nothing is happening yet — that is deliberate. Spend a moment just looking.
2. In the right-hand Scenario / Test panel, set Level to Learner and Case speed to 0.5×. This roughly triples your thinking time and halves the pace of everything.
3. Click ▶ Run random case. Watch the traces. Somewhere in the next minute one of them will start to change.
4. When it does, decide why and click one of the four action buttons. There are only ever four: surgical, physiologic, technical, or observe.
5. Read the debrief. It tells you what the cause actually was and why. That explanation is the point of the exercise — the trace was only the prompt.

2The screen

Four regions, left to right. Everything you need lives in one of them.

The status bar

Along the bottom: displayed time, elapsed case time, and a recording indicator. There is also a running event log in the right column — every alarm, action and stage change is timestamped there, and it is what gets written into a saved case report.

You can annotate the log yourself. Type into the Enter quick event field beneath it and press Enter, or use Events ▸ Insert event marker, Mark incision and Mark closure.

3Changing acquisition settings

This is the question new users ask first, so it gets its own section. The settings panel shows one modality at a time — the one currently selected.

Two ways to choose which modality you are editing

• Click its row in Mode Controls. The row highlights, a small cog appears next to its name, and its settings load in the panel below.
• Use the picker in the Settings — [ SSEP ▾ ] header. It lists every modality you have switched on.

Either way the panel heading changes to <modality> acquisition, and each setting appears as its own card: a label, the current value on the right, and a slider or a dropdown.

What you can change, by modality

Every one of these feeds the trace maths live — turn the averages up and the noise falls, drop the stim current below threshold and the response goes with it.

Sub-channels

dSSEP and cMEP are not separate rows. They are sub-channels you add from inside their parent's settings: select SSEP and switch on Add dermatomal channel, or select MEP and switch on Add corticobulbar (cMEP). They run alongside the parent and share its stimulus.

Signal conditions

At the top of the settings panel, four buttons inject the artefacts you have to learn to recognise: ⚡ Cautery, 60 Hz, Notch and Drift. Turn one on and read what it does to the trace — cautery hash is not a neurotonic train, and knowing the difference is most of the job.

Extra views

Below the modality rows, an Extra views group folds away eight display windows that have no acquisition settings of their own: EEG DSA, Trend Stack, Impedance, Electrode Map, Screw Test, Reflexes, Cortical Map and Performance. Click the header to expand it; the badge tells you how many are currently on.

4Working with trace windows

Each window has icons in its title bar. They are easy to confuse, so:

Drag a title bar to rearrange windows. Display ▸ Layout switches between two, three and four columns. Display ▸ Theme — or the ☾/☼ button in the title bar — switches between the dark workstation look and a light one with white trace windows. Dark is the default, and your choice is remembered.

5Baselines and the alarm check

Capture baselines before anything interesting happens — ⊹ Baselines on the toolbar, or Case ▸ Set baselines. Everything downstream is measured against them.

Once baselines exist, the continuously-averaged evoked windows show an alarm-criteria chip: current amplitude as a percentage of baseline, the latency shift, and a verdict of STABLE, WATCH or ALARM. It applies the conventional rules — a fall to 50% or less of baseline amplitude, or a latency increase of 10% or more.

For how the modelled numbers compare with published standards, see Help ▸ Reference — it sets out what is simplified and what is faithful, modality by modality.

6Running a case

Starting one

• ▶ Run random case — one event on the modality you have selected.
• ▶ Multimodality case — one event that shows up across the whole montage.
• Test ▸ <procedure> — one of 27 named procedures, grouped by category: spine deformity and degenerative, spinal cord and paediatric, vascular, supratentorial and sellar, posterior fossa and craniovertebral, peripheral and ENT. These run in stages with their own montage, physiology and multiple events.

A named procedure loads first and waits — check the pre-op checklist it shows you, then press ▶ Start when you are ready.

Pausing, and the response window

Once a change crosses the alarm threshold you have a limited time to respond, and that window is now shown to you. A bar beneath the metric line counts down from the moment the alarm fires — green, then amber, then red — with the time remaining beside it. Those are real wall-clock seconds, so they stretch when you lower the case speed.

If you need longer than the window allows, ❚❚ Pause on the toolbar — or P — freezes the case. No degradation, no stage advance, no physiologic drift, and the countdown holds where it is. The traces keep moving so the screen does not look dead, but nothing progresses. Choosing an action resumes the case automatically, so you cannot strand yourself in a pause.

The four decisions

Every event comes down to the same question: what kind of problem is this?

Choosing wrongly is not fatal — it is logged as ruling that cause out, and you can try another. But alerting the surgeon for a confounder counts as a false alarm, and the debrief says so. False alarms cost credibility and operating time, and the simulator scores them.

Outcomes

Acting correctly and quickly recovers the signal fully. Acting correctly but late leaves a residual and scores a partial. Never identifying the cause scores a deficit (for a real injury) or missed (for a confounder that resolved on its own).

The debrief

At the end you get what the cause actually was, the teaching point behind it, and — for named procedures — a call-out exercise asking how you would have phrased the alert to the surgeon. Cases with localisable injuries also offer 🫀 Where the injuries actually were, which maps each event onto the neuraxis in sagittal or coronal view.

Case ▸ Save report writes the whole thing out — montage, level, case speed, physiology, the timestamped log and the outcomes.

7Setting the pace

Two independent controls. This matters: one changes how hard the case is, the other changes how fast it runs.

Level — how hard

Level sits on the toolbar beside Case speed, so it stays visible and changeable once a case is under way, and it is mirrored in the Scenario panel when you are idle. Unlike speed it does not take effect instantly: in a staged procedure it applies from the next event onward.

Case speed — how fast

The Speed control on the toolbar runs from 0.5× to 2× and changes the wall-clock pace of the whole case: onset, degradation, stage durations and the response window all scale together. It takes effect immediately, including mid-case — if a case is getting away from you, slow it down without restarting. The response-window countdown reads in real seconds, so lowering the speed visibly buys you more of them.

8The other practice modes

Each drills something the standard case does not.

9Patient, physiology, anaesthesia

The Patient menu opens one panel with four tabs:

• Profile — height, age, BMI, pre-existing deficits. Height genuinely matters: it delays every peak equally, so a long absolute latency in a tall patient is normal while a rising central conduction time is not.
• Physiology — mean arterial pressure, temperature, and a drift toggle that lets the values wander on their own.
• Anaesthesia — volatile MAC, propofol, opioid, ketamine and neuromuscular blockade. Each behaves the way it should: raise the MAC and the MEP goes first; block too deeply and MEP and EMG both disappear while the SSEP sits there unbothered. Ketamine is the interesting one: it is the only agent here that makes signals bigger, augmenting the MEP and the cortical SSEP peak at around 0.5 mg/kg/h while Erb, N13, popliteal and every latency stay exactly where they were. The dose response is deliberately not linear — push toward 1 mg/kg/h and the augmentation reverses.
• Positioning — limb position, head position and dependent side, which is how you produce a positional plexopathy.

All of it feeds the trace maths continuously, so the fastest way to build intuition is to open a panel, move one thing, and watch what happens.

10Tracking your progress

Test ▸ My progress scores four separate skills rather than one number:

The panel shows accuracy day by day, names your weakest of the four skills and offers to drop you straight into practising it, and exports or clears your history on request.

11Keyboard shortcuts

Shortcuts are ignored while the cursor is in any text field or dropdown, and a focused button handles its own keypress rather than firing twice.

12Notes for instructors

• Set the pace to the cohort. First-week students should start at Learner and 0.5×. The no-fail behaviour matters here: a novice who freezes gets to keep thinking instead of watching a deficit accumulate, which is the difference between a teaching moment and a discouraging one.
• Speed is the dial to move first. It changes pacing without changing the clinical difficulty, so a student can practise the same case at 0.5× and then at 1× and see exactly what improved.
• Pause is a teaching control. Freeze a case mid-event with P and the screen holds completely still while you talk through what the trace is doing and why. Committing to an action resumes it, so a student cannot leave it stuck.
• Use the sandboxes for demonstration. Injury Lab and Stim Lab have no clock and no scoring, so they work well on a projector — apply an injury, dial the severity up and down, and talk through what the trace is doing.
• Named procedures are the assessment material. Each runs in stages with its own montage and physiology, and includes confounders as well as real injuries.
• Reports. Case ▸ Save report produces a printable record including the level and case speed used. Case ▸ Print montage prints the current setup.
• Reset between students. Case ▸ Reset layout & settings clears the saved state and returns the console to defaults.
• The scoring is self-study only. It never leaves the browser, so it cannot be used as a verified record of a student's performance. Treat it as formative.

13Glossary