About This Simulation

This interactive web application provides a high-fidelity simulation of multimodality Intraoperative Neuromonitoring (IONM). It is designed as an educational tool for clinicians, technologists, and students to develop a deeper understanding of Motor Evoked Potentials (MEPs) and cortical sensory responses. By simulating realistic clinical events and providing real-time control over display parameters, it offers a dynamic, hands-on environment for learning to interpret complex electrophysiological data and recognize significant changes that may indicate neurological risk during surgery.

The simulation models a full multi-channel montage, including both peripheral muscle (MEP) and cortical (EEG-like) responses. It incorporates signal jitter, physiological noise, and complex waveform morphologies to create a challenging and authentic learning experience.

How to Use the Simulator

The interface is composed of three primary components: the Montage Panel (left), the central Waveform Display, and the Control & Information Panels.

• Channel Selection: Focus on a specific channel by clicking its corresponding location on the montage diagram or by clicking directly on its waveform trace in the main display. The selected channel will be highlighted in both areas for easy identification.
• Event Simulation: Use the buttons in the control panel to trigger common intraoperative scenarios:
  • 💥 Surgical: Simulates a focal ischemic event, such as nerve compression or vascular compromise, causing a critical amplitude drop in a specific anatomical region (left arm). The affected channels will flash red on the montage.
  • 💉 Anesthesia: Simulates a systemic change, like a deepening of anesthesia, which causes a global, moderate amplitude reduction and slight latency increase across all channels. All channels will flash amber to indicate the systemic effect.
  • ✅ Recover / 🔄 Reset: Returns the simulation to the stable, baseline state.
• Display Controls:
  • Gain: Adjusts the vertical sensitivity (amplitude) of the waveforms, measured in microvolts per division (µV/div). Increase gain to magnify low-amplitude signals or decrease it to view high-amplitude signals without clipping.
  • Sweep: Adjusts the horizontal time scale, measured in milliseconds per division (ms/div). A faster sweep (lower ms/div) "stretches" the waveform, allowing for detailed analysis of latency and morphology.
  • Temperature: Simulates patient body temperature (35-38°C). Lower temperatures increase latency and decrease amplitude of muscle responses, reflecting physiological effects of hypothermia commonly seen during surgery.
• Demo Mode: Press ▶️ Play Demo for an automated tour of the simulator's features. It will cycle through different clinical events and parameter changes to showcase the application's full capabilities.

Advanced Features

This simulation includes several advanced features that make it more physiologically accurate:

1. Enhanced MEP Morphology: Muscle MEPs display realistic triphasic patterns with initial positive, main negative, and terminal positive phases, accurately reflecting motor unit action potentials.
2. Realistic D-wave and I-wave Components: Cortical recordings include direct waves (D-waves) and multiple indirect waves (I-waves) with physiologically correct latency differences.
3. Frequency-Specific Noise and Artifacts: The simulation includes baseline drift, physiological tremor, power line interference with harmonics, and realistic motion and cautery artifacts.
4. Trial-to-Trial Variability: The simulator models facilitation and fatigue effects with repeated stimulation, mimicking actual neurophysiological responses during surgery.
5. Temperature Effects: The temperature control simulates the impact of patient temperature on MEP amplitude and latency, providing a realistic representation of common clinical variables.
6. Anesthesia-Specific Effects: The simulation accounts for differential effects of anesthesia on D-waves versus I-waves and shows appropriate distal-to-proximal gradient effects on muscles.

Potential Future Enhancements

This simulation serves as a robust platform for exploring the challenges of real-time IONM data analysis. Future development could expand its capabilities to further bridge the gap between simulation and clinical practice:

1. Automated Measurement Cursors: Implement logic to automatically place measurement cursors on waveforms to calculate peak-to-peak amplitude and onset latency, mirroring the functionality of clinical IONM software.
2. Machine Learning Integration: Utilize the simulation to generate a large, labeled dataset for training machine learning models. A model could be trained to automatically classify waveform changes (e.g., "Normal," "Surgical Event," "Anesthetic Fade"), providing a foundation for a real-time decision support system.
3. Multiple Stimulation Paradigms: Add various stimulation protocols like paired-pulse, train-of-four, and repetitive stimulation with different frequencies to simulate more complex intraoperative testing scenarios.