EDF / EDF+ — European Data Format

Overview

EDF (European Data Format) is a long-established open file format for storing and exchanging multichannel biosignal recordings, most importantly clinical and research EEG, polysomnography, and other continuous physiological time-series. Proposed by Bob Kemp and Josip Värri in 1992 and published in Electroencephalography and Clinical Neurophysiology, EDF is widely supported across clinical EEG hardware and used for clinical neurophysiology recordings. EDF+ (2003) extended it to support time-stamped annotations, discontinuous recordings, and a wider range of signal types. EDF’s key practical properties are its simplicity (no specialist library required to read it) and the absence of a built-in metadata model, meaning electrode coordinates, task structure, and subject information must be stored separately.

Clinical and Research Use

EDF and EDF+ are used for long-term video-EEG monitoring for epilepsy diagnosis, SEEG (stereo-EEG) for pre-surgical epilepsy evaluation, and polysomnography sleep EEG studies for sleep disorder research and neurodegenerative disease cohorts.

Connections

• Accepted by: BIDS (EEG and iEEG format)
• Converts to: NWB (for DANDI deposit)
• Event annotation: HED (HED tags can annotate EDF+ annotation channel events in BIDS)

Resources

• https://www.edfplus.info (EDF+ specification and tools)
• https://www.edfplus.info/specs/edf.html (EDF specification)
• https://www.edfplus.info/specs/edfplus.html (EDF+ specification)
• https://bids-specification.readthedocs.io/en/stable/modality-specific-files/electroencephalography.html (BIDS EEG specification)