file: nstdb.doc G. Moody August 1992
Copyright (C) Massachusetts Institute of Technology 1992. All rights reserved.
This directory contains the second edition of the MIT-BIH Noise Stress Test
Database. The directory includes noise records (`bw', `em', and `ma') that may
be added to ECG records by `nst' to create noise stress test records. It also
contains 12 sample noise stress test records generated by `nst', by adding `em'
noise to MIT-BIH Arrhythmia Database records 118 and 119. File `nstdbgen' is
the UNIX shell script that was used to generate the sample records. For
convenience, reference annotation files are included here; all are copies of
the original reference annotation files for records 118 and 119. The
signal-to-noise ratios (SNRs) during the noisy segments of these records are:
Record SNR (dB) Record SNR (dB)
118e24 24 119e24 24
118e18 18 119e18 18
118e12 12 119e12 12
118e06 6 119e06 6
118e00 0 119e00 0
118e_6 -6 119e_6 -6
The records with SNRs of 0 and -6 dB are written in format 16, since the sample
values occasionally exceed the 12-bit range enforced by format 212 (used for
the other records in this directory).
The directory `old' contains the first edition of the MIT-BIH Noise Stress Test
Database, reproduced here for the sake of completeness. Unless you wish to
repeat an experiment based on the first edition, use the records in this
For further information about: see:
these records `../readme.doc'
signal-to-noise ratio, the ECG Database Applications Guide,
and `nst' or `../src/db/doc/nst.1'
testing noise tolerance of the ECG Database Applications Guide
arrhythmia detectors or `../src/db/doc/eval.tex'
signal file formats the ECG Database Applications Guide
the first edition of `old/oldnstdb.doc'