This research investigates the use of photoplethysmography (PPG) signals measured intraorally for sleep monitoring applications. By capturing PPG data from sensors positioned within the oral cavity, the study explores a novel approach to passive, continuous sleep quality assessment that can be integrated into oral appliances already worn by patients for the treatment of obstructive sleep apnea.
The intraoral measurement site offers unique advantages over traditional wrist- or finger-based PPG sensing locations. The oral mucosa provides access to a rich vascular bed with minimal motion artifact during sleep, enabling high-fidelity extraction of cardiovascular and respiratory signals. These signals can be processed to derive clinically relevant metrics including heart rate variability, respiratory effort patterns, and blood oxygen saturation trends -- key indicators used in sleep staging and sleep-disordered breathing assessment.
The findings support the feasibility of intraoral PPG as a viable sensing modality for sleep monitoring, with potential to transform how oral appliance therapy efficacy is measured. By embedding sensors directly into dental devices that patients already wear nightly, this approach creates a zero-burden monitoring pathway that removes the compliance challenges associated with traditional polysomnography and dedicated wearable sleep trackers.