.TH WABP 1 "7 November 2011" "WFDB 10.5.10" "WFDB Applications Guide"
.SH NAME
wabp \- arterial blood pressure (ABP) pulse detector
.SH SYNOPSIS
\fBwabp -r\fR \fIrecord\fR [ \fIoptions\fR ... ]
.SH DESCRIPTION
.PP
\fBwabp\fR attempts to locate arterial blood pressure (ABP) pulse
waveforms in a continuous ABP signal in the specified \fIrecord\fR.
The detector algorithm is based on analysis of the first derivative of
the ABP waveform.  The output of \fBwabp\fR is an annotation file
(with annotator name \fBwabp\fR) in which all detected beats are
labelled normal.
.PP
\fBwabp\fR can process records containing any number of signals, but
it uses only one signal for ABP pulse detection (by default, the
lowest-numbered ABP, ART, or BP signal; this can be changed using the
\fB-s\fR option, see below).  \fBwabp\fR is optimized for use with
adult human ABPs.  It has been designed and tested to work best on
signals sampled at 125 Hz.  For other ABPs, it may be necessary to
experiment with the sampling frequency as recorded in the input
record's header file (see \fBheader\fR(5)).
.PP
\fBwabp\fR optionally uses the WFDB library's \fIsetifreq\fR function
to resample the input signal at 125 Hz.  
.PP
\fIOptions\fR include:
.TP
\fB-d\fR
Dump the raw and pre-processed input samples in text format on the
standard output, but do not detect or annotate ABP pulses.
.TP
\fB-f\fR \fItime\fR
Begin at the specified \fItime\fR in \fIrecord\fR (default: the beginning of
\fIrecord\fR).
.TP
\fB-h\fR
Print a brief usage summary.
.TP
\fB-H\fR
Read the signal files in high-resolution mode (default: standard mode).
These modes are identical for ordinary records.  For multifrequency records,
the standard decimation of oversampled signals to the frame rate is suppressed
in high-resolution mode (rather, all other signals are resampled at the highest
sampling frequency).
.TP
\fB-R\fR
Resample the input at 125 Hz (default: do not resample).
.TP
\fB-s\fR \fIsignal\fR
Specify the \fIsignal\fR (number or name) to be used for ABP pulse detection
(default: the lowest-numbered ABP, ART, or BP signal).
.TP
\fB-t\fR \fItime\fR
Process until the specified \fItime\fR in \fIrecord\fR (default: the end of the
\fIrecord\fR).
.TP
\fB-v\fR
Verbose mode: print information about the detector parameters.
.SH ENVIRONMENT
.PP
It may be necessary to set and export the shell variable \fBWFDB\fR (see
\fBsetwfdb\fR(1)).
.SH EXAMPLES
.PP
To mark ABP pulses in record slp60 of the slpdb database, beginning 5 minutes
from the start, ending 10 minutes and 35 seconds from the start, and using
signal 1, use the command:
.br
	\fBwabp -r slpdb/slp60 -f 5:0 -t 10:35 -s 1\fR
.br
The output annotations may be read using (for example):
.br
	\fBrdann -r slpdb/slp60 -a wabp\fR
.PP
.br

.SH SEE ALSO
\fBbxb\fR(1), \fBecgpuwave\fR(1), \fBrdann\fR(1), \fBsetwfdb\fR(1),
\fBsqrs\fR(1), \fBwqrs\fR(1)
.PP
Zong W, Heldt T, Moody GB, and Mark RG.
An open-source algorithm to detect onset of arterial blood pressure pulses.
\fIComputers in Cardiology\fR \fB30\fR:259\-262 (2003).
.SH AUTHORS
Wei Zong (wzong@mit.edu) and George B. Moody (george@mit.edu).
.SH SOURCE
http://www.physionet.org/physiotools/wfdb/app/wabp.c