A custom-built single-channel in-ear electroencephalography sensor for sleep phase detection: an interdependent...

Area of Science:

• Neuroscience
• Biomedical Engineering
• Sleep Medicine

Background:

• Sleep is crucial for health, with disruptions impacting quality of life and disease susceptibility.
• Polysomnography (PSG) is the gold standard for sleep studies but is costly, complex, and can disturb natural sleep.
• Simpler, home-based sleep monitoring devices are needed to overcome PSG limitations.

Purpose of the Study:

• To develop and evaluate a novel single-channel in-ear electroencephalography (EEG) sensor for sleep monitoring.
• To assess the performance of the in-ear EEG sensor against polysomnography (PSG) in healthy volunteers and clinical patients.
• To explore the potential of in-ear EEG for accurate sleep classification and parameterization in diverse clinical settings.

Main Methods:

• A single-channel in-ear EEG sensor was integrated into a memory foam earplug using conductive tape.
• Simultaneous recordings of PSG, in-ear EEG, and actigraphy were conducted in 14 healthy volunteers.
• In-ear EEG was also tested in 14 sleep disorder patients, with and without a contralateral scalp reference.

Main Results:

• The in-ear EEG sensor demonstrated strong correlation, agreement, and reliability with PSG in both healthy and patient groups.
• Accurate sleep classification was achieved with the in-ear EEG sensor, a capability not offered by actigraphy.
• The in-ear EEG showed significant promise for simplifying sleep analysis compared to traditional methods.

Conclusions:

• Single-channel in-ear EEG presents a viable, simplified approach for sleep parameterization in both healthy individuals and clinical populations.
• This technology facilitates reliable sleep assessments in various clinical situations, potentially integrating with Level 3 PSG devices.
• In-ear EEG may help address limitations of other sleep monitoring methods, such as overestimation of the apnea-hypopnea index.