Influence of Photoplethysmogram Signal Quality on Pulse Arrival Time during Polysomnography

Area of Science:

• Cardiovascular Physiology
• Sleep Medicine
• Biomedical Signal Processing

Background:

• Polysomnography (PSG) is the gold standard for diagnosing obstructive sleep apnea (OSA).
• Accurate pulse arrival time (PAT) estimation is crucial for tracking nocturnal blood pressure fluctuations during PSG.
• Low-quality photoplethysmogram (PPG) signals can significantly compromise PAT accuracy.

Purpose of the Study:

• To develop a PPG signal-quality assessment algorithm for robust PAT estimation.
• To investigate the influence of PPG signal quality on PAT during various sleep stages and OSA events.

Main Methods:

• Utilized electrocardiogram (ECG) R and T waves to identify PPG pulse onsets.
• Developed a PPG signal-quality assessment algorithm based on ECG synchronization.
• Analyzed 2055 PSG recordings from the MESA database.

Main Results:

• High-quality PPG signals were less frequent during oxygen desaturation and arousal events compared to apnea events.
• Lower PPG signal quality correlated with a higher interquartile range of PAT.
• The proposed algorithm improved PAT evaluation, reducing deviations and enhancing statistical differences between sleep stages and events.

Conclusions:

• The developed algorithm enhances PPG signal quality assessment for more reliable PAT estimation.
• Improved PAT accuracy can lead to more robust nocturnal blood pressure monitoring in PSG studies.
• This method holds potential for improving the diagnosis and management of sleep-related cardiovascular conditions.