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 directory. 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 or `../src/db/doc/signal.5' the first edition of `old/oldnstdb.doc' this database