Control strategy with multivariable fault tolerance module for automatic intravenous anesthesia.

Area of Science:

• Anesthesiology
• Control Systems Engineering
• Biomedical Engineering

Background:

• Automatic propofol infusion systems rely on the Bi-spectral Index Signal (BIS) for dose adjustment.
• BIS signal failures, due to poor signal quality or noise, can lead to inadequate propofol dosing and adverse patient outcomes.

Purpose of the Study:

• To develop an integrated control strategy to ensure safe propofol infusion during BIS signal failure.
• To enhance the robustness of anesthesia automation systems against sensor faults and hemodynamic disturbances.

Main Methods:

• Integration of a multivariable fault tolerance module (MFTM) with a fractional-order Smith predictor controller.
• Utilizing a multivariable pharmacological patient model to predict BIS and analyze drug effects on hemodynamics.
• Testing the control strategy's robustness against surgical stimuli, BIS sensor faults, and hemodynamic disturbances using patient data.

Main Results:

• The proposed control strategy effectively detects BIS sensor faults and estimates BIS during failures.
• Optimized and smooth propofol infusion was achieved, maintaining stable BIS and Mean Arterial Pressure (MAP) signals.
• The system demonstrated stability across a wide range of physiological parameters and disturbances.

Conclusions:

• The developed MFTM and fractional-order Smith predictor controller provide a robust solution for anesthesia automation during BIS failure.
• This approach mitigates risks associated with inadequate propofol dosing, improving patient safety and anesthetic management.