In Situ Investigation of Upper Airway Occlusion in Sleep Disordered Breathing Using Ultrasonic Transducer Arrays

Area of Science:

• Medical Ultrasound
• Sleep Medicine
• Biomedical Engineering

Background:

• Obstructive sleep apnea/hypopnea syndrome (OSAHS) is a prevalent condition affecting breathing during sleep.
• Current diagnostic methods can be invasive or costly.
• There is a need for accessible and non-invasive screening tools for OSAHS.

Purpose of the Study:

• To investigate the feasibility of using ultrasound for real-time, non-invasive detection of upper airway occlusion during OSAHS events.
• To develop and validate an ultrasound-based system for identifying apneic events.

Main Methods:

• Theoretical modeling and in vitro testing of ultrasound propagation in transmission and reflection modes.
• Development and application of a neck-mounted ultrasound system on nine OSAHS patients.
• Simultaneous nocturnal polysomnography for data validation.
• Extraction of nine temporal and four spectral features from ultrasound waveforms.

Main Results:

• Ultrasound waveform analysis yielded 26 quantifiable metrics.
• Statistical analysis confirmed that specific features could detect apneic events in all participants.
• The proposed method demonstrated high sensitivity in identifying breathing cessations.

Conclusions:

• The developed ultrasound technique is a feasible, cost-effective, and non-invasive tool for screening obstructive sleep apnea/hypopnea syndrome.
• This method offers a promising alternative for early detection and management of OSAHS.