Patient Simulator

Real-time physiological signal simulation using a transformer-based surrogate model with ONNX Runtime Web.

Installation

npm install pneumonia-patient-simulator onnxruntime-web

Usage

import { PatientSimulator } from 'pneumonia-patient-simulator';

// Create simulator instance
const simulator = new PatientSimulator({
  fps: 30,           // Simulation frequency (default: 30)
  initialState: 0,   // Initial patient state (default: 0)
});

// Initialize with model and scalers
await simulator.initialize(
  './surrogate_model_v3.onnx',
  './scalers_v3.json'
);

// Subscribe to data events
simulator.on('data', (data) => {
  // Plot variables (fast waveforms)
  console.log('ECG:', data.plot['Ecg.ecg']);
  console.log('Pressure:', data.plot['EithaPressure.pressure']);
  
  // Monitor variables (clinical metrics)
  console.log('Heart Rate:', data.monitor['currentHeartReat.y']);
  console.log('SpO2:', data.monitor['arterial.sO2']);
});

// Subscribe to state changes
simulator.on('stateChange', ({ from, to }) => {
  console.log(`State changed from ${from} to ${to}`);
});

// Start simulation
simulator.start();

// Change patient state
simulator.setState(1); // Pneumonia

// Stop simulation
simulator.stop();

// Clean up
simulator.dispose();

Patient States

| ID | Name | Description | |----|------|-------------| | 0 | Normal | Healthy patient | | 1 | Pneumonia | Patient with pneumonia | | 2 | Ventilated | Patient on mechanical ventilation | | 3 | Stabilized | Stabilized patient |

Output Variables

Plot Variables (Fast Waveforms)

• lungs.q_in[1].p - Lung pressure
• lungs.q_in[1].m_flow - Lung flow
• Ecg.ecg - ECG signal
• EithaPressure.pressure - Arterial pressure waveform

Monitor Variables (Clinical Metrics)

• filter.y - Filtered signal
• currentHeartReat.y - Heart rate
• HRAdd.y - HR additive component
• arterialPressure.systolic - Systolic BP
• arterialPressure.diastolic - Diastolic BP
• arterial.sO2 - Arterial oxygen saturation
• arterial.pO2 - Arterial partial pressure O2
• arterial.pCO2 - Arterial partial pressure CO2
• arterial.pH - Arterial pH
• tissueUnit[1].pH - Tissue pH
• venous.pH - Venous pH

API Reference

PatientSimulator

Constructor

new PatientSimulator(config?: SimulatorConfig)

Methods

| Method | Description | |--------|-------------| | initialize(modelPath, scalersPath) | Load ONNX model and scalers | | start() | Start simulation loop | | stop() | Stop simulation loop | | setState(state: 0-3) | Set patient state | | getState() | Get current state | | getStateInfo() | Get state name and ID | | isActive() | Check if running | | getTimestep() | Get current timestep | | reset() | Reset to initial state | | on(event, callback) | Subscribe to events | | off(event, callback) | Unsubscribe from events | | dispose() | Clean up resources |

Events

| Event | Payload | Description | |-------|---------|-------------| | data | SimulationData | Emitted at each simulation step | | stateChange | { from, to } | Emitted when state changes | | start | { timestep } | Emitted when simulation starts | | stop | { timestep } | Emitted when simulation stops | | error | Error | Emitted on error |

Model Files

The package requires two model files:

• surrogate_model_v3.onnx - ONNX model file
• scalers_v3.json - Normalization parameters

These should be served from your application and their paths provided to initialize().

Browser Compatibility

Requires browsers with WebAssembly support (all modern browsers).

License

MIT