File: mitdb.txt G. Moody August 1992 Last revised: 16 May 1997 The MIT-BIH Arrhythmia Database Copyright (C) Massachusetts Institute of Technology 1997. All rights reserved. Overview ======== The MIT-BIH Arrhythmia Database consists of 48 annotated records, obtained from 47 subjects studied by the Arrhythmia Laboratory of Beth Israel Hospital in Boston between 1975 and 1979. About 60% of the records were obtained from inpatients. The database contains 23 records (the `100 series') chosen at random from a set of over 4000 24-hour Holter tapes, and 25 records (the `200 series') selected from the same set to include a variety of rare but clinically important phenomena that would not be well-represented by a small random sample. Several records in the 200 series were chosen specifically because features of the rhythm, QRS morphology, or signal quality may be expected to present significant difficulty to arrhythmia detectors. Each record is slightly over 30 minutes in length. Each signal file contains two signals sampled at 360 Hz. The header files include information about the leads used, the patient's age, sex, and medications. (This information is reproduced in the MIT-BIH Arrhythmia Database Directory.) The reference annotation files include beat, rhythm, and signal quality annotations. Each of the roughly 109,000 beats was manually annotated by at least two cardiologists working independently; their annotations were compared, consensus on disagreements was obtained, and the reference annotation files were prepared. Four records (102, 104, 107, and 217) include paced beats. The original analog tapes do not represent the pacemaker artifacts with sufficient fidelity to permit them to be recognized by pulse amplitude (or slew rate) and duration alone, the method commonly used for real-time processing. The database records reproduce the analog recordings with sufficient fidelity to permit use of pacemaker artifact detectors designed for tape analysis, however. The MIT-BIH Arrhythmia Database has been used at approximately 300 sites worldwide. Since its initial release in 1980, sixteen errors in beat annotations have been discovered and corrected. No such errors have been found since 1987. A single error in a rhythm label (in record 203) was corrected in the second edition of the CD-ROM, published in August 1992. No changes have been made since then; the current (third) edition of the CD-ROM, published in May, 1997, contains the same version of the MIT-BIH Arrhythmia Database as was included in the second edition. This directory contains ten-minute excerpts from the beginnings of records 100, 119, and 203 of the MIT-BIH Arrhythmia Database; in addition, a shorter (one- minute) excerpt from the beginning of record 100, named `100s', is also included here. The 1-minute excerpt consists of a signal file (100s.dat) containing digitized samples of the two ECG signals, an annotation file (100s.atr) containing labels for each beat (QRS complex) in the record, and a header file (100s.hea) that names the signal file and describes the signals. The format defined for the MIT-BIH Arrhythmia Database was later used (and extended) for the European ST-T Database, the MIT-BIH Polysomnographic Database, the MGH/MF Waveform Database, and the MIMIC Database. The ten-minute excerpts are named `x_100', `x_119', and `x_203', and consist of sets of three similarly-named files. Record x_100 is relatively clean and uncomplicated; record x_119 contains many ventricular ectopic beats but is also relatively clean; and record x_203 is exceedingly complex (high-grade VEA together with AF and noise). References ========== Mark, R.G., Schluter, P.S., Moody, G.B., Devlin, P.H., and Chernoff, D. An annotated ECG database for evaluating arrhythmia detectors. Frontiers of Engineering in Health Care: Proceedings of the 4th Annual Conference of the IEEE Engineering in Medicine and Biology Society, pp. 205-210. New York: IEEE Press (1982). Moody, G.B., and Mark, R.G. The MIT-BIH Arrhythmia Database on CD-ROM and software for use with it. Computers in Cardiology 17:185-188 (1990). [This paper describes the first edition of this CD-ROM.] About the CD-ROM ================ In all, the CD-ROM contains several hundred ECG recordings, over two hundred hours. Individual recordings contain one to three signals and range from 20 seconds to nearly 24 hours in length; most have two signals, are about 30 minutes long, and are annotated beat-by-beat. About one-sixth of the disk is occupied by the MIT-BIH Arrhythmia Database, which is fully annotated. The disk also contains eight additional ECG databases, samples of several others, and a substantial collection of software, mostly in C source form, for use with them. The disk is written in ISO 9660 format, readable on MS-DOS, UNIX, and (with appropriate drivers) Macintosh, VMS, and other systems. The software can be compiled without modification under MS-DOS or UNIX, and with only minor changes on the Macintosh or other systems for which K&R or ANSI C compilers are available. The recordings are found in ten directories on the CD-ROM: mitdb MIT-BIH Arrhythmia Database cudb Creighton University Ventricular Tachyarrhythmia Database nstdb MIT-BIH Noise Stress Test Database stdb MIT-BIH ST Change Database vfdb MIT-BIH Malignant Ventricular Arrhythmia Database afdb MIT-BIH Atrial Fibrillation/Flutter Database cdb MIT-BIH ECG Compression Test Database svdb MIT-BIH Supraventricular Arrhythmia Database ltdb MIT-BIH Long-Term ECG Database odb Other databases (excerpts from several compatible CD-ROMs of physiologic signals) The disk contains three additional directories: html Documentation in hypertext form, suitable for reading using a Web browser software DB Software Package (version 9.7.0 sources), `wave' (version 6.1 binaries for x86 Linux, SPARC Solaris, and SPARC SunOS), `wview' (version 1.03 alpha binaries for MS-Windows), and other software udb Ancillary files for use with the software The `mitdb', `cudb', and `nstdb' directories contain digitized signals and reference annotations that must be used for testing ECG analyzers in accordance with current and proposed standards published by the Association for the Advancement of Medical Instrumentation (AAMI). The DB Software Package includes reference implementations of the algorithms specified by AAMI for deriving ECG analyzer performance statistics from comparisons of reference and analyzer-produced annotation files. Further information =================== Please visit our Web site, http://ecg.mit.edu, for further information on these and related topics. If you have questions about the sample record or about the CD-ROM, please call or write to: George B. Moody Harvard-MIT Division of Health Sciences and Technology Massachusetts Institute of Technology, Room 20A-113 77 Massachusetts Ave. Cambridge, MA 02139 USA e-mail: george@hstbme.mit.edu phone: +1 617 253 7424 fax: +1 617 253 2514