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+<html>
+<head>
+<title>MIT-BIH Arrhythmia Database Directory (Foreword)</title>
+</head>
+<body bgcolor="#FFFFFF">
+
+<a href="mitdbdir.htm"><h1 align=center>MIT-BIH Arrhythmia Database Directory
+</h1></a>
+
+<p>
+<b>Next:</b> <a href="intro.htm">Introduction</a>
+<b>Up:</b> <a href="mitdbdir.htm#toc">Contents</a>
+
+<a name="foreword"><h1>Foreword [from the first edition]</h1></a>
+<p>
+For a number of years our group has been investigating methods for real-time
+ECG rhythm analysis.  In the course of this work, we have developed an
+extensive annotated digital ECG database.  The database has been enormously
+helpful to us in algorithm development and evaluation.  The creation of this
+resource required a major effort, and was funded, in part, by both government
+and industry.  We feel it is highly desirable to make this database available
+to other academic and industrial groups, and hence have prepared it for
+distribution.  This catalog contains detailed descriptions of the database
+tapes.
+<p>
+We acknowledge with gratitude the many dedicated hours of work which
+went into this project on the part of cardiologists, Holter technicians,
+laboratory assistants, and engineers in our laboratories at MIT and at
+Beth Israel Hospital.  We also acknowledge the help of our colleagues at
+Washington University, St. Louis (particularly Russell Hermes) in
+assuring a compatible data format.  We especially wish to recognize:
+<ul>
+<li>
+<i>Paul Schluter</i>, who did the original design and implementation of the
+database.
+<li>
+<i>Scott Peterson</i>, who supervised the detailed data selection,
+digitization, annotation, and editing at Beth Israel Hospital.  He also
+contributed substantially to the development of software needed for using the
+database in our evaluation.
+<li>
+<i>George Moody</i>, who converted the database to a format compatible with
+that used by the AHA database, and who contributed in a major way to the
+directory.
+<li>
+<i>Larry Siegal</i>, who contributed to development of the waveform editor
+system.
+<li>
+<i>Cheryl Jackson</i>, who was responsible for most of the detailed
+transcription of cardiologist annotations, the comparison and quality control
+functions, and who assembled the final manuscript for the directory.
+<li>
+<i>Diane Perry</i>, who as chief technician in the Arrhythmia Laboratory helped
+to identify suitable data, and who helped in the annotation process.
+<li>
+The group of physicians who helped with the difficult task of beat-by-beat
+annotation of the ECGs:
+Dr. Esmerey Acarturk, Dr. John Aumiller, Dr. Sidney Blake, Dr. Alvin
+Blaustein, Dr. Chester Conrad, Dr. Gary Heller, Dr. Michael Malagold,
+Dr. Roger Mark, and Dr. Candice Miklozek.
+</ul>
+
+<p>
+Roger Mark<br>
+Walter Olson<br>
+<br>
+Cambridge, Massachusetts<br>
+September, 1980<br>
+
+<hr>
+<h2>Notes on the second edition</h2>
+<p>
+During the eight years since we first published this book, nearly one hundred
+academic and industrial research groups worldwide have used the MIT-BIH
+Arrhythmia Database.  We thank these organizations for their support.
+<p>
+In addition to those listed above, we also wish to recognize the
+contributions of:
+<ul>
+<li>
+<i>Joe Mietus</i>, who handled correspondence as well as production and
+distribution of the database from the Beth Israel Hospital, and who analyzed
+the mechanical sources of analog tape wow and flutter.
+<li>
+<i>Ted Baker</i>, who helped in the first ``port'' of the database from our
+homebrew 8080-based systems.
+</ul>
+<p>
+In lieu of reprinting the first edition of this volume, we have made use of
+modern printing technology to produce a far more readable and complete record
+of the contents of the database.  
+<p>
+In June, 1987, the Association for the Advancement of Medical Instrumentation
+published its <i>Recommended Practice for Testing and Reporting
+Performance Results of Ventricular Arrhythmia Detection Algorithms</i>
+(AAMI ECAR-1987), which may be obtained from AAMI, 3330 Washington Boulevard,
+Suite 400, Arlington, VA 22201.
+The MIT-BIH and AHA Databases provide developers and evaluators of arrhythmia
+detectors with standard test data;  the AAMI Recommended Practice provides
+guidelines for using these databases in a standard way, and for describing
+detector performance in a manner that facilitates comparisons between
+detectors.
+We urge all users of our database to follow the AAMI recommendations when
+preparing performance statistics for publication.
+<p>
+A package of C-language software for using the MIT-BIH and AHA Databases
+is available from MIT.  The package
+includes programs for plotting ECGs with annotations, sampling rate
+conversion, and beat-by-beat comparison of annotation files following the
+AAMI recommended practice, as well as a variety of other useful programs.
+All the programs access the database via a common library of subroutines,
+which are also provided as part of the package and which may be used with
+user programs.
+<p>
+We have made several other sets of ECG recordings available, including
+specialized databases for ventricular fibrillation, atrial fibrillation,
+and ST segment changes.  These databases are not annotated beat-by-beat.
+
+<p>
+George Moody<br>
+Roger Mark<br>
+<br>
+Cambridge, Massachusetts<br>
+August, 1988
+
+<hr>
+
+<h2>Notes on the third edition</h2>
+<p>
+Since the publication of the second edition, the database has been made
+available in CD-ROM format.  Continued strong interest in the database has made
+it possible to prepare a second edition of the CD-ROM and a third edition of
+this book.  The CD-ROM includes the additional specialized databases mentioned
+above, and the second edition of the CD-ROM also contains the software
+package mentioned above.
+<p>
+Compatible databases of ECGs and other physiologic signals are beginning to
+appear.  Of particular interest to users of our database is the European ST-T
+Database, which consists of ninety two-hour ECG recordings with beats, rhythms,
+and signal quality annotated as in the MIT-BIH Arrhythmia Database, and with
+additional annotations to indicate ST and T-wave morphology changes.  For
+information, write to: CNR Institute of Clinical Physiology, Computer
+Laboratory, via Trieste, 41, 56100 Pisa, Italy.
+<p>
+I wish to thank all of those who have supported this project over these years,
+especially Roger Mark, who has guided it from its inception in 1975.
+
+<p>
+George Moody<br>
+<br>
+Cambridge, Massachusetts<br>
+July, 1992
+
+<hr>
+
+<h2>Notes on this HTML edition</h2>
+<p>
+Although the MIT-BIH Arrhythmia Database has been available for almost 17 years
+at this writing, it remains in demand among researchers and instrument
+developers.  This edition of the Directory accompanies the third edition of
+the MIT-BIH Arrhythmia Database CD-ROM;  it is the first to appear in hypertext
+form.
+<p>
+If you have installed Netscape on your system, and have set up as a Netscape
+helper application either <tt>wavescript</tt> (see <a
+href="/physiotools/wug/node45.htm"><i>Controlling <em>WAVE</em> from a web
+browser</i></a>) or <tt>wvscript</tt> (see <a
+href="/physiotools/wview/index.shtml"><i>Setting up WVSCRIPT</i></a>), you may
+follow the links from this guide to the records.
+<p>
+Once again, I wish to thank everyone who has supported this project through
+their continued interest in this database.
+
+<P><ADDRESS>
+<I><A HREF="mailto:george@mit.edu">George B. Moody (<tt>george@mit.edu</tt>)</A></ADDRESS></I><BR>
+24 May 1997 (Links updated 11 November 1999 for PhysioNet)
+</body>
+</html>
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+<html>
+<head>
+<title>MIT-BIH Arrhythmia Database Directory (Introduction)</title>
+</head>
+<body bgcolor="#FFFFFF">
+
+<a href="mitdbdir.htm"><h1 align=center>MIT-BIH Arrhythmia Database Directory
+</h1></a>
+
+<p>
+<b>Next:</b> <a href="records.htm">Records</a>
+<b>Up:</b> <a href="mitdbdir.htm#toc">Contents</a>
+<b>Previous:</b> <a href="foreword.htm">Foreword</a>
+
+<a name="intro"><h1>Introduction</h1></a>
+<p>
+This introduction describes how the database records were
+obtained, and discusses the characteristics of the recorded signals.
+Following these notes are annotated ``full disclosure'' plots of the entire
+database.  These can be useful for obtaining an overall
+impression of the contents of individual records.  Following the
+``full disclosure'' plots are sample ECG strips.  These strips
+were chosen to illustrate the salient features of each record.
+Next are notes on the important features of each record.
+These notes also include background information on the subjects,
+including their medications.
+At the end of the book are tables of rhythms and annotations, which
+summarize the contents of the database.
+These tables can be helpful in finding a record with a specific
+set of characteristics.
+
+<a name="selection"><h2>Selection criteria</h2>
+<p>
+The source of the ECGs included in the MIT-BIH Arrhythmia Database is a
+set of over 4000 long-term Holter recordings that were obtained
+by the Beth Israel Hospital Arrhythmia Laboratory between 1975 and 1979.
+Approximately 60% of these recordings were obtained from inpatients.
+The database contains 23 records
+(numbered from 100 to 124 inclusive with some numbers missing)
+chosen at random from this set, and 25 records
+(numbered from 200 to 234 inclusive, again with some numbers missing)
+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 of Holter recordings.
+Each of the 48 records is slightly over 30 minutes long.
+<p>
+The first group is intended to serve as a representative sample of the
+variety of waveforms and artifact that an arrhythmia detector might
+encounter in routine clinical use.  A table of random numbers was used
+to select tapes, and then to select half-hour segments of them.
+Segments selected in this way were excluded only if neither of the two
+ECG signals was of adequate quality for analysis by human experts.
+<p>
+Records in the second group were chosen to
+include complex ventricular, junctional,
+and supraventricular arrhythmias and conduction abnormalities.  Several
+of these records were selected because features of the rhythm, QRS
+morphology variation, or signal quality may be expected to present
+significant difficulty to arrhythmia detectors;  these records have
+gained considerable notoriety among database users.
+<p>
+The subjects were 25 men aged 32 to 89 years, and 22 women aged 23 to 89
+years.  (Records 201 and 202 came from the same male subject.)
+
+<a name="leads"><h2>ECG lead configuration</h2></a>
+<p>
+In most records, the upper signal is a modified limb lead II (MLII),
+obtained by placing the electrodes on the chest.  The lower signal is
+usually a modified lead V1 (occasionally V2 or V5, and in one instance V4);
+as for the upper signal, the electrodes are also placed on the chest.
+This configuration is routinely used by the BIH Arrhythmia Laboratory.
+Normal QRS complexes are usually prominent in the upper signal.
+The lead axis for the lower signal may be nearly orthogonal to the mean
+cardiac electrical axis, however (i.e., normal beats are usually
+biphasic and may be nearly isoelectric).
+Thus normal beats are frequently difficult to discern in the lower signal,
+although ectopic beats will often be more prominent (see, for example, record
+106).
+A notable exception is record 114, for which the signals were reversed.
+Since this happens occasionally in clinical practice, arrhythmia detectors
+should be equipped to deal with this situation.
+In records 102 and 104, it was not possible to use modified lead II because of
+surgical dressings on the patients;
+modified lead V5 was used for the upper signal in these records.
+
+<a name="analog"><h2>Analog recording and playback</h2></a>
+<p>
+The original analog recordings were made using nine Del Mar Avionics
+model 445 two-channel recorders, designated <i>A</i> through <i>I</i>:
+<table border>
+<tr><th><i>Recorder</i></th><th><i>Records</i></th></tr>
+<tr><td align=center><i>A</i></td><td>102, 107, 111, 115, 121</td></tr>
+<tr><td align=center><i>B</i></td><td>212</td></tr>
+<tr><td align=center><i>C</i></td><td>203</td></tr>
+<tr><td align=center><i>D</i></td><td>118, 124, 217</td></tr>
+<tr><td align=center><i>E</i></td>
+  <td>101, 103, 106, 108, 112, 117, 119, 122, 209, 219, 220, 223, 233</td></tr>
+<tr><td align=center><i>F</i></td>
+  <td>104, 109, 123, 205, 207, 210, 215, 221</td></tr>
+<tr><td align=center><i>G</i></td>
+  <td>100, 105, 114, 116, 213, 214, 222, 228</td></tr>
+<tr><td align=center><i>H</i></td><td>113, 201, 202, 231</td></tr>
+<tr><td align=center><i>I</i></td><td>200, 230, 232, 234</td></tr>
+</table>
+<br>
+(It is not known which recorder was used for record 208.)
+<p>
+During the digitization process, the analog recordings were played back
+on a Del Mar Avionics model 660 unit.  The analog tapes used for records
+112, 115 through 124, 205, 220, 223, and 230 through 234 were played back
+and digitized at twice real time;  the rest were played back at real time
+using a specially constructed capstan for the model 660 unit.
+Skew between the two signals was found to be as great as 40
+milliseconds for some of the analog recorders.
+In addition to the fixed skew that results from extremely small differences
+in the orientations of the tape heads on the recorder and the playback unit,
+microscopic vertical wobbling of the tape, either during recording or playback,
+introduces a variable skew, which may be comparable in magnitude to the fixed
+skew.
+This problem (which also
+occurs on the AHA database) may present difficulties for certain two-channel
+analysis methods designed for real-time applications.
+<p>
+Minor tape speed variations should not pose problems for typical arrhythmia
+detectors.  It is difficult to avoid tape sticking or slippage during low-speed
+playback, and several episodes of tape slippage were noted and marked with
+comment annotations.  Wow and flutter should be studied carefully in the
+context of heart-rate variability studies, since flutter compensation
+was not possible in these recordings.  A number of frequency-domain artifacts
+have been identified and related to specific mechanical components of the
+recorders and the playback unit:
+<table border>
+<tr><th><i>Frequency (Hz)</i></th><th><i>Source</i></th></tr>
+<tr><td align=center>0.042</td><td>Recorder pressure wheel</td></tr>
+<tr><td align=center>0.083</td><td>Playback unit capstan (for twice real-time playback)</td></tr>
+<tr><td align=center>0.090</td><td>Recorder capstan</td></tr>
+<tr><td align=center>0.167</td>
+  <td>Playback unit capstan (for real-time playback)</td></tr>
+<tr><td align=center>0.18-0.10</td>
+  <td>Takeup reel (frequency decreases over time)</td></tr>
+<tr><td align=center>0.20-0.36</td>
+  <td>Supply reel (frequency increases over time)</td></tr>
+</table>
+<br>
+The most significant of these artifacts by far is the 0.167 Hz artifact on
+recordings that were played back at real time.  The next largest is the
+0.090 Hz artifact;  the 0.083 Hz artifact on recordings that were played back
+at twice real-time is of roughly the same magnitude as the 0.090 Hz artifact.
+The 0.042 Hz artifact is of much lower magnitude.  Other frequencies
+related to the drive train (at 0.42 Hz, 1.96 Hz, 9.1 Hz, and
+42 Hz) do not appear as noticeable artifacts.
+The frequencies of the last two artifacts listed in the table depend on
+how much tape is on the supply and takeup reels;  the supply reel causes
+a much more noticeable artifact than does the takeup reel.  Other
+frequency-domain artifacts generated by the supply reel appear in the
+0.10-0.18 Hz and 0.30-0.54 Hz bands.
+<p>
+Four of the 48 records (102, 104, 107, and 217) include paced beats.
+The original analog recordings 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.
+
+<a name="digitization"><h2>Digitization</h2></a>
+<p>
+The analog outputs of the playback unit
+were filtered to limit analog-to-digital converter (ADC)
+saturation and for anti-aliasing,
+using a passband from 0.1 to 100 Hz relative to real time, well
+beyond the lowest and highest frequencies recoverable from the recordings.
+The bandpass-filtered signals were
+digitized at 360 Hz per signal relative to real time
+using hardware constructed at the MIT Biomedical Engineering Center and
+at the BIH Biomedical Engineering Laboratory.
+The sampling frequency was chosen to facilitate implementations of 60 Hz
+(mains frequency) digital notch filters in arrhythmia detectors.
+Since the recorders were battery-powered, most of the 60 Hz noise present
+in the database arose during playback.
+In those records that were digitized at twice real time, this noise appears
+at 30 Hz (and multiples of 30 Hz) relative to real time.
+<p>
+Samples were acquired from each signal almost simultaneously (the intersignal
+sampling skew was on the order of a few microseconds).  As noted above, analog
+tape skew was several orders of magnitude larger.  The ADCs were
+unipolar, with 11-bit resolution over a &plusmn;5 mV range.  Sample values thus
+range from 0 to 2047 inclusive, with a value of 1024 corresponding to zero
+volts.
+<p>
+The 11-bit samples were originally recorded in 8-bit first difference format
+(this was necessary because of limited mass storage capacity).  Given the
+sampling frequency and the resolution of the ADC, the difference encoding
+implies a maximum recordable slew rate of &plusmn;225 mV/s.  In practice, this
+limit was exceeded by the input signals very infrequently, only during severe
+noise on a small number of records.  The effect on the quality of the recorded
+signals is totally negligible.  On this CD-ROM, the samples have been
+reconstructed from the first differences and stored as pairs of 12-bit
+amplitudes packed in triplets of consecutive bytes (for details on the storage
+format, see <a href="/physiotools/wag/signal-5.htm">signal(5)</a>).
+
+<a name="annotations"><h2>Annotations</h2></a>
+<p>
+An initial set of beat labels was produced by a simple slope-sensitive
+QRS detector, which marked each detected event as a normal beat.  Two
+identical 150-foot chart recordings were printed for each 30-minute record,
+with these initial beat labels in the margin.
+For each record, the two charts were given to two cardiologists, who worked
+on them independently.  The cardiologists added additional beat labels
+where the detector missed beats, deleted false detections as necessary,
+and changed the labels for all abnormal beats.  They also added rhythm
+labels, signal quality labels, and comments.
+<p>
+The annotations were transcribed from the paper chart recordings.
+Once both sets of cardiologists' annotations for a given record
+had been transcribed and verified, they were automatically compared
+beat-by-beat, and another chart recording was printed.  This chart showed
+the cardiologists' annotations in the margin, with all discrepancies
+highlighted.  Each discrepancy was reviewed and resolved by consensus.
+The corrections were transcribed, and the annotations were then analyzed
+by an auditing program, which checked them for consistency and which
+located the ten longest and shortest R-R intervals in each record (to
+identify possible missing or falsely detected beats).
+<p>
+In early copies of the database, most beat labels were placed
+at the R-wave peak, but manually inserted labels were not always
+located precisely at the peak.
+In copies of the database made since 1983, the beat labels have been shifted
+from their original locations.  
+The ECG (usually the upper signal) was digitally bandpass-filtered to
+emphasize the QRS complexes, and each beat label was moved to the major local
+extremum, after correction for phase shift in the filter.
+A few noisy beats were manually realigned.
+This process was applied to all records except record 117 in 1983; the
+beat labels for record 117 were not realigned until March 1998, however.
+The result is that annotations generally appear at the R-wave peak, and
+are located with sufficient accuracy to make the reference annotation
+files usable for studies requiring waveform averaging and for
+heart rate variability studies (but note the comments
+with respect to analog tape wow and flutter above).
+In the annotated ECG plots produced by <tt>psfd</tt> and <tt>pschart</tt>,
+and in printed copies of this directory, each label is placed so that the
+fiducial mark for the annotation corresponds to the left edge of the label.
+<p>
+The database contains approximately 109,000 beat labels.  Sixteen
+were corrected in the first seven years after the database was released in 1980
+(in records 104, 108, 114, 203, 207, 217, and 222);  in addition,
+all of the left bundle branch block beats in record 214 were originally
+labelled as normal beats.  The rhythm labels
+have been more substantially revised and now include notations for paced
+rhythm, bigeminy, and trigeminy, which were missing in early copies.
+<p>
+In October 1998, a rhythm label in record 203 was corrected.  In
+October 2001, a seventeenth error in the beat labels was discovered
+and corrected (in record 209).  In April 2003, 26 PVC annotations in
+record 119 were manually realigned by small amounts (up to 74 ms).  In
+May 2003, an eighteenth error in the beat labels was discovered and
+corrected (in record 214).  In April 2005, many of the episodes
+previously labelled as atrial fibrillation in record 222 were
+partially or completely relabelled as atrial flutter.  In April 2008,
+three beat labels were corrected (two in record 108, and one in record
+215).  In June 2010, the 22nd and 23rd errors in the beat labels were
+found and corrected (both in record 203).  Thanks to Bob Bruce, Pat
+Hamilton, Yin Dengfeng, Roger Mark, Sebastian Vasquez, and Mariano
+Llamedo Soria for finding and reporting these errors.
+
+<hr>
+
+<a name="symbols"><h1>Symbols used in plots</h1></a>
+
+<p>
+[An expanded and updated version of the table below can be found at
+<a href="/physiobank/annotations.shtml">
+<tt>http://www.physionet.org/physiobank/annotations.shtml</tt></a>.]
+
+<p>
+<table border>
+<tr><th><i>Symbol</i></th><th><i>Meaning</i></th></tr>
+<tr><td><b>&middot;</b> <i>or</i> N</td><td>Normal beat</td></tr>
+<tr><td>L</td><td>Left bundle branch block beat</td></tr>
+<tr><td>R</td><td>Right bundle branch block beat</td></tr>
+<tr><td>A</td><td>Atrial premature beat</td></tr>
+<tr><td>a</td><td>Aberrated atrial premature beat</td></tr>
+<tr><td>J</td><td>Nodal (junctional) premature beat</td></tr>
+<tr><td>S</td><td>Supraventricular premature beat</td></tr>
+<tr><td>V</td><td>Premature ventricular contraction</td></tr>
+<tr><td>F</td><td>Fusion of ventricular and normal beat</td></tr>
+<tr><td>[</td><td>Start of ventricular flutter/fibrillation</td></tr>
+<tr><td>!</td><td>Ventricular flutter wave</td></tr>
+<tr><td>]</td><td>End of ventricular flutter/fibrillation</td></tr>
+<tr><td>e</td><td>Atrial escape beat</td></tr>
+<tr><td>j</td><td>Nodal (junctional) escape beat</td></tr>
+<tr><td>E</td><td>Ventricular escape beat</td></tr>
+<tr><td>/</td><td>Paced beat</td></tr>
+<tr><td>f</td><td>Fusion of paced and normal beat</td></tr>
+<tr><td>x</td><td>Non-conducted P-wave (blocked APB)</td></tr>
+<tr><td>Q</td><td>Unclassifiable beat</td></tr>
+<tr><td>|</td><td>Isolated QRS-like artifact</td></tr>
+<tr><td colspan=2 align=center>Rhythm annotations appear <i>below</i> the
+level used for beat annotations:</td></tr>
+<tr><td>(AB</td><td>Atrial bigeminy</td></tr>
+<tr><td>(AFIB</td><td>Atrial fibrillation</td></tr>
+<tr><td>(AFL</td><td>Atrial flutter</td></tr>
+<tr><td>(B</td><td>Ventricular bigeminy</td></tr>
+<tr><td>(BII</td><td>2&deg; heart block</td></tr>
+<tr><td>(IVR</td><td>Idioventricular rhythm</td></tr>
+<tr><td>(N</td><td>Normal sinus rhythm</td></tr>
+<tr><td>(NOD</td><td>Nodal (A-V junctional) rhythm</td></tr>
+<tr><td>(P</td><td>Paced rhythm</td></tr>
+<tr><td>(PREX</td><td>Pre-excitation (WPW)</td></tr>
+<tr><td>(SBR</td><td>Sinus bradycardia</td></tr>
+<tr><td>(SVTA</td><td>Supraventricular tachyarrhythmia</td></tr>
+<tr><td>(T</td><td>Ventricular trigeminy</td></tr>
+<tr><td>(VFL</td><td>Ventricular flutter</td></tr>
+<tr><td>(VT</td><td>Ventricular tachycardia</td></tr>
+<tr><td colspan=2 align=center>Signal quality and comment annotations appear <i>above</i>
+the level used for beat annotations:</td></tr>
+<tr><td><i>qq</i></td>
+<td>
+Signal quality change:  the first character (`c' or `n') indicates the quality
+of the upper signal (clean or noisy), and the second character indicates the
+quality of the lower signal</td></tr>
+<tr><td>U</td><td>Extreme noise or signal loss in both signals:  ECG is unreadable</td></tr>
+<tr><td>M (<i>or</i> MISSB)</td><td>Missed beat</td></tr>
+<tr><td>P (<i>or</i> PSE)</td><td>Pause</td></tr>
+<tr><td>T (<i>or</i> TS)</td><td>Tape slippage</td></tr>
+</table>
+
+<HR>
+<P><ADDRESS>
+<I><A HREF="mailto:george@mit.edu">George B. Moody (<tt>george@mit.edu</tt>)</A></ADDRESS></I><BR>
+24 May 1997
+<br>
+<i>Revised 24 June 2010</i>
+</body>
+</html>
@@ -0,0 +1,154 @@
+<HTML>
+<HEAD>
+<TITLE>MIT-BIH Arrhythmia Database Directory</TITLE>
+</HEAD>
+<BODY bgcolor="#AOD0FF">
+<BR> <P>
+<H1 ALIGN=CENTER>MIT-BIH Arrhythmia Database Directory</H1>
+<P ALIGN=CENTER><STRONG>Hypertext edition, 24 May 1997<BR>
+(Based on the printed third edition, 23 July 1992)<BR>
+<BR> 
+<BR> 
+<BR> 
+Harvard-MIT Division of Health Sciences and Technology<BR> 
+Biomedical Engineering Center</STRONG></P><P>
+<P>
+Copyright &#169; 1980, 1988, 1992, 1997 Massachusetts Institute of Technology.
+<P>
+The database described in this directory can be downloaded without charge
+from
+<A HREF="http://physionet.org/physiobank/database/mitdb/">http://physionet.org/physiobank/database/mitdb/</A>
+(located at MIT, in Cambridge, MA, USA) and from
+PhysioNet <a href="/mirrors/">mirrors</a> worldwide.
+
+<P>
+You may print your own copy of this directory, with illustrations.  See
+the <a href="src/makefile">makefile for UNIX</a> or the
+<a href="src/printdir.bat">batch file for MS-DOS</a> for further information.
+<P>
+Permission is granted to make and distribute verbatim copies of this
+guide provided that the copyright notice and this permission notice are
+preserved on all copies.
+<P>
+Permission is granted to copy and distribute modified versions of this
+guide under the conditions for verbatim copying, provided also that the
+entire resulting derived work is distributed under the terms of a
+permission notice identical to this one.
+<P>
+Permission is granted to copy and distribute translations of this guide
+into another language, under the above conditions for modified versions.
+<P>
+<BR> <HR>
+<a name="toc"><H2>Table of Contents</H2></a>
+
+<ul>
+<li> <a href="foreword.htm">Foreword</a>
+<li> <a href="intro.htm">Introduction</a>
+     <ul>
+     <li> <a href="intro.htm#selection">Selection criteria</a>
+     <li> <a href="intro.htm#leads">ECG lead configuration</a>
+     <li> <a href="intro.htm#analog">Analog recording and playback</a>
+     <li> <a href="intro.htm#digitization">Digitization</a>
+     <li> <a href="intro.htm#annotations">Annotations</a>
+     <li> <a href="intro.htm#symbols">Symbols used in plots</a>
+     </ul>
+<li> <a href="records.htm">Records</a>
+<table>
+<tr>
+<td><a href="records.htm#100">100</a>
+<td><a href="records.htm#104">104</a>
+<td><a href="records.htm#108">108</a>
+<td><a href="records.htm#113">113</a>
+<td><a href="records.htm#117">117</a>
+<td><a href="records.htm#122">122</a>
+<td><a href="records.htm#201">201</a>
+<td><a href="records.htm#207">207</a>
+<td><a href="records.htm#212">212</a>
+<td><a href="records.htm#217">217</a>
+<td><a href="records.htm#222">222</a>
+<td><a href="records.htm#231">231</a></tr>
+<tr>
+<td><a href="records.htm#101">101</a>
+<td><a href="records.htm#105">105</a>
+<td><a href="records.htm#109">109</a>
+<td><a href="records.htm#114">114</a>
+<td><a href="records.htm#118">118</a>
+<td><a href="records.htm#123">123</a>
+<td><a href="records.htm#202">202</a>
+<td><a href="records.htm#208">208</a>
+<td><a href="records.htm#213">213</a>
+<td><a href="records.htm#219">219</a>
+<td><a href="records.htm#223">223</a>
+<td><a href="records.htm#232">232</a></tr>
+<tr>
+<td><a href="records.htm#102">102</a>
+<td><a href="records.htm#106">106</a>
+<td><a href="records.htm#111">111</a>
+<td><a href="records.htm#115">115</a>
+<td><a href="records.htm#119">119</a>
+<td><a href="records.htm#124">124</a>
+<td><a href="records.htm#203">203</a>
+<td><a href="records.htm#209">209</a>
+<td><a href="records.htm#214">214</a>
+<td><a href="records.htm#220">220</a>
+<td><a href="records.htm#228">228</a>
+<td><a href="records.htm#233">233</a></tr>
+<tr>
+<td><a href="records.htm#103">103</a>
+<td><a href="records.htm#107">107</a>
+<td><a href="records.htm#112">112</a>
+<td><a href="records.htm#116">116</a>
+<td><a href="records.htm#121">121</a>
+<td><a href="records.htm#200">200</a>
+<td><a href="records.htm#205">205</a>
+<td><a href="records.htm#210">210</a>
+<td><a href="records.htm#215">215</a>
+<td><a href="records.htm#221">221</a>
+<td><a href="records.htm#230">230</a>
+<td><a href="records.htm#234">234</a></tr>
+</table>
+
+<li> <a href="tables.htm">Tables</a>
+<ul>
+<li> <a href="tables.htm#allbeats">Table of beat types (entire records)</a>
+<li> <a href="tables.htm#allrhythms">Table of rhythms (entire records)</a>
+<li> <a href="tables.htm#testbeats">Table of beat types (test periods only)</a>
+<li> <a href="tables.htm#testrhythms">Table of rhythms (test periods only)</a>
+</ul>
+</ul>
+
+<BR><HR>
+<H2>Other links of interest</H2>
+<UL>
+<LI><A HREF="http://ecg.mit.edu">The MIT-BIH Database Distribution
+Home Page</A><BR>
+Information about CD-ROM databases of ECGs and other physiologic signals,
+and related software.
+<LI><I><A HREF="/physiotools/wpg/">WFDB Programmer's Guide</A></I>
+<BR>
+Includes tutorial and reference material relating to the WFDB library,
+a portable set of functions (subroutines) for reading and writing files in the
+formats supported by the applications described here.  The WFDB library may be
+used with C, C++, or Fortran programs;  the guide primarily describes the C
+interface.
+<LI><I><A HREF="/physiotools/wag/">WFDB Applications Guide</A></I>
+<BR>
+Includes <TT>man</TT> pages for the applications included in the WFDB Software
+Package, specifications for file formats supported by the DB library.  Detailed
+installation instructions for the WFDB Software Package are included in an
+appendix, and a second appendix discusses how the performance of ECG analyzers
+can be formally evaluated using standard reference databases and the standard
+evaluation tools included in the WFDB Software Package.
+<LI><I><A HREF="/physiotools/wug/">WAVE User's Guide</A></I><BR>
+A comprehensive tutorial, with extensive reference material, for
+<STRONG>WAVE</STRONG>, an interactive waveform browser with facilities for
+annotation editing and control of external analysis programs.
+<STRONG>WAVE</STRONG> runs on PCs under the free Linux operating system, and
+on SPARC-based systems under SunOS or Solaris.
+</UL>
+<BR> <HR>
+<P><ADDRESS>
+<I><A HREF="mailto:george@mit.edu">George B. Moody (<tt>george@mit.edu</tt>)</A></ADDRESS></I><BR>
+24 May 1997 (Links updated 31 October 2001 for PhysioNet)
+</BODY>
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