Sleep cycles

Description

This tool computes and report the sleep cycles.

Sleep cycles typically last around 90 minutes to 2 hours, during which time the brain cycles from slow-wave sleep to REM sleep. Sleep cycles are succession of NREM-REMs periods.

Simple definition of NREM Period (NREMP)

  • First NREMP : begins at the first NREM stage of the recording.

  • Central NREMPs : begin at the next NREM stage following a REMP end.

  • The NREMP ends at the start of a REMP.

REM Period (REMP)

  • The REMP ends when there are 15 min without an R stage (except at the last cycle).

  • The end is defined as the last R stage of the REMP or the beginning of the next NREMP.

  • The REMP begins at the first stage R.

Steps

1 - Input Files

Start by opening your PSG files (.edf, .eeg or .sts).

  • The .tsv file is also needed for the EDF format.

  • The .sig file is also needed for Stellate format.

  • The whole NATUS subject folder is also needed for the .eeg format.

2 - Cycle Definition

Select or edit your sleep cycle criteria.

3 - Output Files

Sleep Cycle Cohort file :

  • The start and duration (s) of each NREM and REM period are saved in a .tsv (tab separated values) file defined by the user.

  • The file includes 5 columns : group, name, start_sec, duration_sec and channels.

  • Each row corresponds to a period and the group identifies the PSG recording.

  • New PSG recording are added in the .tsv file if it exists otherwise it is created.

Sleep Cycle specific to each PSG opened:

  • The hypnogram of each PSG is saved in a .png picture file

  • The sleep stages and sleep periods events are saved in a .tsv file