Bench model to simulate upper airway obstruction for analyzing automatic continuous positive airway pressure devices

Area of Science:

• Respiratory Mechanics
• Sleep Medicine
• Biomedical Engineering

Background:

• Automatic positive airway pressure (APAP) devices are crucial for treating obstructive sleep apnea (OSA).
• Some APAP devices exhibit unstable performance when encountering specific events or artifacts.
• A need exists to evaluate APAP device responses under realistic conditions.

Purpose of the Study:

• Develop a bench model simulating real-world flow, snoring, and obstructive patterns.
• Compare APAP devices using flow/snoring detection with those incorporating the forced oscillation technique (FOT).

Main Methods:

• A bench model simulated apneas (with/without obstruction), hypopneas (with/without snoring), flow limitation, and artifacts (leaks, mouth expiration).
• APAP devices were subjected to these simulated conditions.
• Device pressure responses were recorded and analyzed.

Main Results:

• Most devices increased pressure during apneas with obstruction, but at varying rates (2.5-13 min to reach 10 cm H2O).
• APAP devices using FOT did not alter pressure for non-obstructive apneas, unlike flow/snoring devices.
• Four devices failed to adjust pressure for obstructive hypopneas; most increased pressure for snoring.
• Mask leaks had minimal impact, but mouth expiration artifacts caused pressure increases in four devices.

Conclusions:

• Integrating upper airway resistance measurement alongside flow and snoring signals enhances APAP event detection accuracy.
• FOT-based APAP devices demonstrate more stable responses to certain non-obstructive events.
• Device performance varies significantly based on detection algorithms and simulated artifacts.