Respiratory Inductance Plethysmography to Quantify Changes in Ventilation in Obstructive Sleep Apnea

Area of Science:

• Respiratory Physiology
• Sleep Medicine
• Biomedical Engineering

Background:

• Current obstructive sleep apnea (OSA) assessments often rely on airflow, which can be inaccurate with oral breathing.
• Respiratory inductance plethysmography (RIP) offers an alternative for ventilation measurement.

Purpose of the Study:

• To evaluate RIP's capability in quantifying ventilation changes.
• To determine if RIP can provide advanced metrics for OSA severity.
• To address limitations of current airflow-based OSA measures.

Main Methods:

• Compared RIP-based ventilation estimates with a gold standard oronasal-pneumotach in 89 adult OSA patients.
• Assessed concordance at breath, event depth, and patient-specific severity levels.
• Developed and applied a "RIP correction" method to address overestimation during obstruction.

Main Results:

• RIP correction significantly reduced overestimation bias for individual breaths (12% to 2% eupnea) and event depth (9% to 1% eupnea).
• Underestimation of average event depth was attenuated (9% to 4% eupnea), and ventilatory burden improved (275 to 116% eupnea min/hr).
• RIP correction enhanced agreement (ICC) for event depth and patient-level OSA severity metrics.

Conclusions:

• Processed RIP signals effectively quantify ventilation-based metrics for OSA.
• This approach provides a reliable alternative to airflow-based measures, unaffected by breathing route.
• RIP shows promise for advanced OSA severity assessment.