Wearable Sleep EEG and Auditory Stimulation in Healthy Adults

Participants will complete eligibility screening and provide written informed consent before beginning study procedures. At enrollment, University of Houston study personnel will provide training on placement and removal of the forehead sensor, use of the study smartphone and application, device handling and charging, reporting of discomfort or technical problems, and procedures for stopping device use.

Participants will use the wearable EEG-based sleep-monitoring system at home during natural sleep for up to 12 weeks, with a target of at least 15 usable nights of sleep data. The external, battery-powered, non-invasive system records EEG and device-session information, supports automated sleep-stage detection, and delivers brief, low-volume pink-noise sounds during selected stages of non-rapid eye movement sleep according to study-configured closed-loop timing parameters. The device does not deliver electrical stimulation to the participant. Device and auditory-stimulation settings will be configured by study personnel and will not be adjusted by participants.

During the home-use period, participants will complete smartphone-based assessments that include sleep-diary information, sleep quality, mood, stress, device feedback, and memory tasks. Study personnel will provide technical assistance and monitor device use, data quality, participant-reported discomfort, and device or application problems.

Study analyses will focus on home-use feasibility, completion of usable recording nights, participant adherence, EEG signal quality, automated sleep-stage classification, slow-wave activity, delta sleep ratio, auditory-stimulation timing and delivery performance, application completion, and safety and tolerability. Findings will be used to refine the wearable system, signal-processing algorithms, participant instructions, and study procedures before a later clinical assessment in adults with major depressive disorder.

Inclusion criteria

• Age 18-30 years.
• Able to provide independent written informed consent.
• Able to read and speak English.
• Generally healthy and maintains a regular sleep schedule.
• Willing and able to use the wearable EEG system at home during sleep and complete smartphone-based assessments.
• Adequate hearing to perceive the auditory stimulation.
• Able to follow device-use, safety-reporting, and study procedures.

Exclusion criteria

• Diagnosed sleep disorder, including insomnia or sleep apnea.
• Diagnosed psychiatric condition, including major depressive disorder or an anxiety disorder.
• Neurological disorder, including epilepsy, seizure disorder, or significant traumatic brain injury.
• Hearing impairment that would interfere with auditory stimulation.
• Use of medication expected to substantially affect sleep, mood, or study outcomes, including sedative-hypnotic or relevant psychoactive medication.
• Known allergy or sensitivity to device materials, adhesives, conductive materials, or other skin-contact components.
• Current pregnancy.
• Cognitive impairment or another condition preventing independent consent. Prisoner status.
• Student or employee over whom the investigator or study personnel have direct grading, supervisory, employment, or evaluative authority.
• Acute illness, dizziness, significant headache or earache, excessive fatigue, or another temporary safety or data-quality concern at the time of study procedures. Participation may be deferred or rescheduled when appropriate.