electroencephalography (EEG), electrocardiogram (ECG), pulse oximetry, airflow, and leg movements. Sleep stages are assigned by human experts based on visua...

https://www.apple.com/jp/healthcare/docs/site/Estimating_Sleep_Stages_from_Apple_Watch_Sept_2023.pdf

, an audiologist performed a visual and otoscopic exam of each participant’s ear canals to confirm there were no occluding factors to air conduction (such a...

https://www.apple.com/jp/health/pdf/Hearing_Health_Features_on_AirPods_Pro_2_October_2024.pdf