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About MASS

The Montreal Archive of Sleep Studies (MASS) is an open-access and collaborative database of laboratory-based polysomnography (PSG) recordings O’Reilly, C., et al. (2014) J Seep Res, 23(6):628-635. Its goal is to provide a standard and easily accessible source of data for benchmarking the various systems developed to help the automation of sleep analysis. It also provides a readily available source of data for fast validation of experimental results and for exploratory analyses. Finally, it is a shared resource that can be used to foster large-scale collaborations in sleep study.

MASS is composed of cohorts themselves comprising subsets. Recordings within subsets is kept as homogeneous as possible, whereas it is more heterogeneous between subsets. To allow inter-study comparisons, researchers validating their results on MASS are encouraged to specify which portion of the database they used in their assessment (e.g., MASS-C1 for the whole cohort 1, MASS-C1/SS1-SS3 for subsets 1, 2 and 3 of cohort 1).

Currently, the first MASS cohort available is described in O’Reilly, C., et al. (2014) J Seep Res, 23(6):628-635. This cohort comprises polysomnograms of 200 complete nights recorded in 97 men and 103 women of age varying between 18 and 76 years (mean: 38.3 years, SD: 18.9 years). It has been split in five different subsets:

  • SS1
  • SS2
  • SS3
  • SS4
  • SS5

To get access to the MASS database

To allow an access that is as unrestricted as possible while keeping high ethical standards regarding the protection of subject’s privacy, we have separated the information of the database in four kinds of data with appropriate access requirements. These types are as follow:

  • Biosignals: Polysomnographic data provided as EDF++ files including only the biosignals (EEG, EKG, EMG, EOG, etc.). Access to these files requires that the investigators submit a copy of their project (as approved by their local ethics board) and a proof of ethical approval. Upon reception of these documents, we will provide to the requesting investigators the whole set of PSG files.
  • Subset-specific annotations*: Polysomnographic annotations provided as EDF++ files.
  • Open-access descriptors: Comma-separated values (CSV) files including basic recording and scoring information. In some cases, sleep-related indexes are also included.
  • Restricted-access descriptors: CSV files including further information such as demographic (age, gender, education) variables. Access to these files requires stating the hypotheses that are to be investigated such that we may check that they do not conflict with other studies currently being run.

Access requests can be filed by emailing your request here: tyna.paquette.cnmtl@ssss.gouv.qc.ca.

In your request for access, please state which set of data you need access to (the whole cohort 1 or identify which specific subset you need from the following: SS1, SS2, SS3, SS4 and/or SS5) as well as which type of data you need:

  • Biosignals and sleep stages
  • Subset-specific annotations* – access will be given with a link to download files
  • Open-access descriptors – link to dowload file will be available shortly
  • Restricted-access descriptors

As stated previously, to give you access to type 1 (Biosignals and sleep stages) and/or type 4 (Restricted-access descriptors) of the MASS database, we need two documents from you:

  • A description of the project in which MASS would be used
  • A copy of the accreditation from your local research ethics board for this project

Furthermore, regarding for the Restricted-access descriptors, a full project description is required to present to the MASS scientific committee before sharing that data. In this project description, please state the research hypotheses that are to be investigated with these data. The MASS scientific committee will verify that these hypotheses are not already being investigated before granting access.

Once your dossier is complete (documents a) and b) referred to above, if required), we will send you the license for use of the MASS database. If you agree to the terms, the MASS data you requested will be shared through OneDrive Professional by sharing subset specific folders.

* Please note that the subset-specific annotations have now passed quality control checks and are currently shared via link to OneDrive folders. If you already made the request for these files, you will be contacted as soon. The subset-specific annotations will soon also be available for download directly on the website. Check the website for updates. PSG biosignals will never be available for direct download on the website.

If you require further information that could be was found the on the old website, please click here.

For any question regarding MASS, please contact the database manager Tyna Paquette.

Please stay tuned for further updates on the MASS database and its website.