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Apnea, Bariatric surgery, and CPAP study

Polysomnography introduction

Patients underwent attended polysomnography (PSG) using the Compumedics E-Series (Abbotsford, Victoria Australia).


Signal and annotation files

Raw polysomnography data are available for ABC participants at baseline and at follow-up. Each recording has a signal file (.EDF) and two versions of the event scoring and epoch staging annotations (.XML).

  1. EDF - Signal files in the European Data Format exported from Compumedics Profusion.
  2. XML (Profusion) - Annotation files exported from Compumedics Profusion. (Learn more...)
  3. XML (NSRR) - Annotation files processed in the EDF Editor and Translator tool.

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 event tags

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.

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.

Known issues

  • None at this time.

History / changelog

July 2018

  • Polysomnography data uploaded to sleepdata.org after exports from Compumedics Profusion


Please reach out to us at support@sleepdata.org or in the Forum if you have questions.

National Sleep Research Resource
Apnea, Bariatric surgery, and CPAP study