The MIMIC Database: Numerics

This directory contains 121 records (one for each recording in the MIMIC Database) that contain periodic measurements of physiologic variables obtained from bedside ICU monitors. This section of the MIMIC Database is called Numerics because these measurements are those that typically appear in numeric form on the ICU monitors' screens: heart rate, blood pressure (mean, systolic, diastolic), respiration rate, oxygen saturation, etc. Since the data-gathering protocol was designed to have minimal impact on patient monitoring or care, the selection of measured variables varies among these records, according to the requirements of the ICU staff for appropriate care of the patients in each case.

If you wish to download all of the files in this directory without selecting each one individually, try using a utility for batch HTTP transfers such as wget, available here in source form for all versions of UNIX and as a precompiled binary for MS-Windows. Most Linux distributions include wget. Once you have installed wget, retrieve these files using

wget -r -np http://www.physionet.org/physiobank/database/mimicdb/numerics/
(or substitute the name of a nearby PhysioNet mirror for www.physionet.org above). The files in this directory occupy 548 megabytes.

These records vary in length from about an hour to more than 77 hours; most are about 35-40 hours in length. About one-third of the patients in the MIMIC Database are represented by two (in a few cases, three) recordings. The total length of these records is approximately 4658 hours.

The measurements in these records, sampled at intervals of 1.024 seconds (0.976563 Hz), have been derived from the raw signals in the directories reached from like-numbered links on the MIMIC Database home page. (At this time, 72 of these directories have been posted here; the remaining 49 are not yet available. If you have a particular interest in one or more records that are not yet on-line, please send us a note and we will attempt to accommodate your request.) The complete MIMIC Database will include these records, the raw signals, and accompanying clinical data for each case, extracted from medical records.

Each of the 121 records consists of a (text) header file, a (binary) signal file, and 2 (binary) annotation files, identified by suffix:

Suffix Meaning
.hea header file, describing signal file contents and format
.dat signal file
.al annotations corresponding to patient status alarms
.in annotations corresponding to monitoring condition alarms

In addition, a fifth (text) file, with suffix .xws, is provided for viewing each record using WAVE. If you are running Linux and have installed WAVE, you may click on the .xws file associated with each record to view that record without downloading it first. WAVE and the related WFDB software package may be downloaded from this site.

Patient status alarms refer to events that (as determined by the ICU monitor) require medical intervention (for example, observation of heart rate or blood pressure outside of preset limits). Monitoring condition alarms refer to events that interfere with the function of the monitor (for example, transducer malfunction or signal saturation). Note that these alarms are as reported by the ICU monitors, including all false alarms. Once an alarm condition is detected, the monitors produce alarms at intervals of 1.024 seconds until reset by the ICU staff, or until the variable that triggered the alarm returns to its nominal range. There are also significant events in some cases that did not trigger alarms (and are therefore not annotated in the .al or .in files).

Patient status and monitoring condition alarms were not recorded for the first 5 cases (032, 033, 037, 039, and 041), so the .al and .in files for these 5 records are empty.