Flexible Hybrid Intraoral Sleep Monitoring System

This study presents a novel flexible hybrid intraoral sleep monitoring system that incorporates the measurement of photoplethysmography (PPG) signals, temperature, and head position from the intraoral cavity during sleep. The monitoring system is designed to be flexible and conform to the arch shape of the oral cavity, with all electronic components and sensors housed on a flexible substrate. To securely attach the system to the oral appliance, acrylic material was utilized for its transparency and biocompatibility. The experimental results demonstrate that the use of acrylic material and the intraoral measurement location have no adverse impact on the quality of the PPG signals. The PPG signal acquired by the flexible hybrid monitoring system has a similarity of over 97% compared to the reference signals. Thus, the intraorally acquired signals can be effectively used to estimate different sleep stages and the apnea-hypopnea index. This flexible hybrid intraoral monitoring system shows great potential for non-invasive sleep monitoring in home or outpatient settings.