The MIMIC II Waveform Database Matched Subset

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This is version 3.1 of the MIMIC II Waveform Database Matched Subset (January 2012; 4,897 waveform records and 5,266 numerics records matched with 2,809 MIMIC II Clinical Database records).

The MIMIC II databases are described in

M. Saeed, M. Villarroel, A.T. Reisner, G. Clifford, L. Lehman, G.B. Moody, T. Heldt, T.H. Kyaw, B.E. Moody, R.G. Mark. Multiparameter intelligent monitoring in intensive care II (MIMIC-II): A public-access ICU database. Critical Care Medicine 39(5):952-960 (2011 May); doi: 10.1097/CCM.0b013e31820a92c6.

Please cite this publication when referencing this material, and also include the standard citation for PhysioNet:

Goldberger AL, Amaral LAN, Glass L, Hausdorff JM, Ivanov PCh, Mark RG, Mietus JE, Moody GB, Peng C-K, Stanley HE. PhysioBank, PhysioToolkit, and PhysioNet: Components of a New Research Resource for Complex Physiologic Signals. Circulation 101(23):e215-e220 [Circulation Electronic Pages;]; 2000 (June 13).

The MIMIC II Waveform Database Matched Subset (mimic2wdb/matched) contains all MIMIC II Waveform Database records that have been associated with MIMIC II Clinical Database records. The record matching process is ongoing, and more records may be added to the matched subset in the future.

Each subdirectory of this directory contains one or more MIMIC II Waveform Database records that have been matched with a single subject (whose MIMIC II Clinical Database Subject_ID is the name of the subdirectory). The name of each mimic2wdb/matched waveform record is of the form


where NNNNN is the matching MIMIC II Clinical Database Subject_ID, and YYYY, MM, DD, hh, and mm are the surrogate year, month (01-12), and day (01-31), and the real hour (00-23) and minute (00-59), derived from the starting date and time of day of the mimic2wdb/matched record. The surrogate dates match those of the corresponding MIMIC II Clinical Database version 2.6 (or later) records; note that surrogate dates in previous versions of the MIMIC II Clinical Database differ from those in version 2.6 and later.

In most cases, the waveform record is paired with a numerics record (see the description of numerics records on the MIMIC II Waveform Database home page). The numerics record names are of the form


i.e., identical to the name of the associated waveform record except for the appended n.

Frequently there are multiple waveform and numerics record pairs associated with a given clinical record; all of them will appear in the same subdirectory in such a case, and their names will indicate their chronologic sequence. For example, MIMIC II Clinical Database record s00079 has been matched with two waveform and numerics record pairs, named

s00079/s00079-2756-08-14-01-25    s00079/s00079-2756-08-14-01-25n
s00079/s00079-2756-08-14-12-28    s00079/s00079-2756-08-14-12-28n

Each mimic2wdb/matched record is also an undated mimic2wdb record (i.e., it also belongs to the full MIMIC II Waveform Database). Only the surrogate-dated mimic2wdb/matched header (.hea) files are unique to the MIMIC II Waveform Database Matched Subset; the others, with names of the form 3*.hea and 3*.dat, are copies of the like-named files in the full database. (Actually, they are symbolic links to the original files, a distinction that matters only when copying them using rsync, which can be used to download them quickly if the undated records have been downloaded previously.)

See the MIMIC II Waveform Database home page for additional information about these records.

Downloading the Matched Subset

Most users will not need to download the entire MIMIC II Waveform Database Matched Subset. For those who think they do, please see Can I download an entire PhysioBank database in one step? in the PhysioNet FAQ.

If you have already downloaded parts 0 through 9 of the MIMIC II Waveform Database, version 3, and your OS supports symbolic links, use this command (as in the FAQ) to download the Matched Subset:

rsync -Cavz /usr/database/mimic2wdb/matched

The command above will require only a few minutes in most cases, since nearly all of the files in the Matched Subset are shared with files in parts 0 through 9 that have been downloaded already.

If, however, you wish to download the Matched Subset without having previously downloaded the entire MIMIC II Waveform Database, version 3, or if your OS does not support symbolic links, use these commands instead:

mkdir -p /usr/database/mimic2wdb/matched
rsync -CaLvz /usr/database/mimic2wdb/matched

This command will download about 550 GB, and will require at least a few hours; if you do not have a high-speed network connection it may require a day or more.