Waveform Database Software Package (WFDB) for MATLAB and Octave 0.10.0

File: <base>/mcode/wabp.m (3,909 bytes)
function varargout=wabp(varargin)
%
% wabp(recName,beginTime,stopTime,resample,signal)
%
%    Wrapper to WFDB WABP:
%         http://www.physionet.org/physiotools/wag/wabp-1.htm
%
% Attempts to locate arterial blood pressure (ABP) pulse waveforms in a continuous ABP signal
% in the specified WFDB record "recName". The detector algorithm is based on analysis of the first derivative
% of the ABP waveform. The output of WABP is an annotation file (with annotator name WABP) in which all
% detected beats are labelled normal.
%
% WABP 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
% 'signal' option, see below). WABP 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 WFDBDESC ).
%
%
%
% CITING CREDIT: To credit this function, please cite the following paper at your work:
%
% Zong, W., Heldt, T., Moody, G. B., & Mark, R. G. (2003).
% An open-source algorithm to detect onset of arterial blood pressure pulses.
% Computers in Cardiology 2003, 30, 259-262. IEEE.
%
%
%Required Parameters:
%
% recName
%       String specifying the name of the record in the WFDB path or
%       in the current directory.
%
%
% Optional Parameters are:
%
% beginTime (Optional)
%       String or integer specifying the begin time. The
%       WFDB time format is described at
%       http://www.physionet.org/physiotools/wag/intro.htm#time.
%       If an integer is entered, it  should be between 1
%       (first sample) and N (last sample).
%
% stopTime (Optional)
%       String or integer specifying the begin time. If string, it should be
%       in WFDB time format, if it is an integer, should be between 1
%       (first sample) and N (last sample).
%
% resample
%       A 1x1 boolean. If true resamples the signal to 125 Hz (default=0).
%
% signal
%       A 1x1 integer. Specify the signal index of the WFDB record to be
%       used for ABP pulse detection.
%
%
% C Source file written by Wei Zong 1998
% C Source file revised by George Moody 2010
%
% MATLAB Wrapper Written by Ikaro Silva, 2013
% Last Modified: January 16, 2013
% Version 1.1
%
% Since 0.9.0
%
% See also RDANN, RDSAMP, WFDBDESC, WFDBTIME
%
%
% %Example - Note this will create the file: ./slpdb/slp60.wabp in you
% %directory
% N=2000;
% [signal,Fs,tm]=rdsamp('slpdb/slp60',2,N);
% [endTime,dateStamp]=wfdbtime('slpdb/slp60',N);
% wabp('slpdb/slp60',[],endTime{1},[],2);
% [ann]=rdann('slpdb/slp60','wabp')
% plot(tm,x);hold on;grid on
% plot(tm(ann),x(ann),'or')
%

%endOfHelp
persistent javaWfdbExec
if(isempty(javaWfdbExec))
    [javaWfdbExec]=getWfdbClass('wabp');
end

%Set default pararamter values
inputs={'recName','beginTime','stopTime','resample','signal'};
beginTime=[];
stopTime=[];
resample=0;
signal=[];
for n=1:nargin
    if(~isempty(varargin{n}))
        eval([inputs{n} '=varargin{n};']);
    end
end

wfdb_argument={'-r',recName};

if(~isempty(beginTime))
    wfdb_argument{end+1}='-f';
    %Convert to string if sample number is entered
    if(isnumeric(beginTime))
        [beginTime,~]=wfdbtime(recName,beginTime);
    end
    wfdb_argument{end+1}=beginTime;
end
if(~isempty(stopTime))
    wfdb_argument{end+1}='-t';
    %Convert to string if sample number is entered
    if(isnumeric(stopTime))
        [stopTime,~]=wfdbtime(recName,stopTime);
    end
    wfdb_argument{end+1}=[stopTime];
end
if(resample)
    wfdb_argument{end+1}='-R';
end
if(~isempty(signal))
    wfdb_argument{end+1}='-s';
    wfdb_argument{end+1}=num2str(signal-1);
end

err=javaWfdbExec.execToStringList(wfdb_argument);
if(~isempty(strfind(err.toString,['annopen: can''t'])))
    error(err);
end