file: oldnstdb.doc		G. Moody	August 1992

Copyright (C) Massachusetts Institute of Technology 1992.  All rights reserved.


This directory 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 the main
`nstdb' directory of this disk (see `../nstdb/nstdb.doc').

In the main `nstdb' directory, very long-term baseline drift (less than 0.05
Hz) has been removed from records `bw', `em', and `ma'.  The original versions
of these records from the first edition of this disk are records `oldbw',
`oldem', and `oldma' in this directory.

The signal-to-noise ratios of the sample noise stress test records in this
directory are not calibrated as stated in the `readme.doc' file on the first
edition of this disk.  Using the same definition of SNR as for the records in
the main `nstdb' directory, the SNRs for these records are (in dB):

	Record  Signal 0  Signal 1      Record  Signal 0  Signal 1
	118_02     19.79     14.38      119_02     20.31     13.79
	118_04     13.77      8.36      119_04     14.29      7.77
	118_06     10.25      4.84      119_06     10.76      4.25
	118_08      7.75      2.34      119_08      8.27      1.75
	118_10      5.81      0.41 (*)  119_10      6.33     -0.19
	118_12      4.23     -1.18      119_12      4.74     -1.77

(*) Signal 1 was inadvertently omitted from the version of record 118_10 that
appeared on the first edition of this disk;  it has been restored here.