The polysomnography recording (Compumedics E-series; Compumedics, Abbotsford, Australia) consisted of the following: two electroencephalograms (C3/C2 and C4/C1), bilateral electrooculograms, a bipolar submental electromyogram, thoracic and abdominal respiratory inductance plethysmography (Compumedics Summit IP), airflow (by a Protec nasal–oral thermocouple [Protec, Wordsville, WA] and nasal pressure recording), finger pulse oximetry (Nonin model 320 pulse oximeter [Nonin Medical, Plymouth, MA] with displayed waveform), electrocardiogram, body position, and monitoring bilateral leg movements by piezoelectric sensors. Nocturnal recordings were transmitted to the centralized reading center at Brigham and Women's Hospital and data were scored by trained technicians using current guidelines.
Raw polysomnography data are available for 515 Cleveland Children's Sleep and Health Study participants. Each recording has a signal file (.EDF) and two versions of the event scoring and epoch staging annotations (.XML).
NSRR XML files can be overlaid onto EDF signal files using the EDF Viewer tool. For more information about the XML translation (mapping) process, review the files available on the EDF Editor and Translator Releases page.
Hypopnea events are represented by two different tags in the XML annotation files. Events with the
Hypopnea tag are hypopneas with a reduction in airflow between 30% and 50% from baseline levels. Events with the
Unsure tag are hypopneas with a reduction in airflow greater than 50% from baseline levels.
If interested in all hypopneas that have a 30% or more reduction in airflow, both event types should be included. If interested in events with greater reduction in airflow (>50%), use those that were labeled with the
Unsure tag does not represent uncertainty about the event, but rather was the only custom tag available in the original polysomnography scoring program.
Additional criteria can be applied to limit events based on associated desaturation and/or arousal.