Included HEP.ibi

Included variable HEP.ibi to easily access the interbeat intervals obtained by any peak detection method.

Functions/heplab_calculate_IBIs.m

@@ -27,8 +27,7 @@
 
     % calculate IBIs
     RR=RRtimes(1:length(RRtimes)-1);
-    RR1=RRtimes(2:length(RRtimes));
-    RRinterval=RR1-RR;
+    RRinterval=diff(RRtimes);
 
     % convert to sec and remove first interval
     RRtimes=RRtimes(2:length(RRtimes))/1000;

Functions/heplab_calculate_IBIs.m~

@@ -0,0 +1,43 @@
+% heplab_calculate_IBIs - Calculates IBIs, called by heplab_ecgplot.m
+% 
+% Copyright (C) 2019 Pandelis Perakakis, Granada University, [email protected]
+%
+% This program is free software: you can redistribute it and/or modify
+% it under the terms of the GNU General Public License as published by
+% the Free Software Foundation, either version 3 of the License, or
+% (at your option) any later version.
+%
+% This program is distributed in the hope that it will be useful,
+% but WITHOUT ANY WARRANTY; without even the implied warranty of
+% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+% GNU General Public License for more details.
+%
+% You should have received a copy of the GNU General Public License
+% along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+
+function [RRinterval, RRtimes]=heplab_calculate_IBIs(qrs,signal_sec,srate)
+
+if length(qrs)>1,
+
+    time=0:1/srate:signal_sec-1/srate; % time axis
+
+    % convert to ms
+    RRtimes=round(1000*time(qrs));
+
+    % calculate IBIs
+    RR=RRtimes(1:length(RRtimes)-1);
+    RR1=RRtimes(2:length(RRtimes));
+    RRinterval=diff(RRtime);
+
+    % convert to sec and remove first interval
+    RRtimes=RRtimes(2:length(RRtimes))/1000;
+
+    % round IBIs
+    RRinterval=round(RRinterval);
+
+else
+    RRinterval=-1;
+    RRtimes=-1;
+end
+

Functions/heplab_ecgplot.m

@@ -59,7 +59,7 @@
     plot(t,signal,'b-',t,qrs,'ro');
 end
 
-% fing events within window
+% find events within window
 [RRinterval, RRtimes]=heplab_calculate_IBIs(r_ind,length(ecg)*1/srate,srate);
 if RRinterval(1)~=-1,
 

README.md

@@ -65,7 +65,7 @@ If you have previously saved a file containing a HEP structure, you can use this
 
 ### Tools
 #### Detect R waves
-- **ecglab fast** and **ecglab slow** are two very similar peak detection algorithms included in the *ECGLAB*, developed by the group of João Luiz Azevedo de Carvalho at the University of Brasilia, DF, Brasil. Details about the algorithm are given in [Carvalho et al., 2002](Documentation/Articles/icsp2002_ecglab.pdf).
+- **ecglab fast** and **ecglab slow** are two very similar peak detection algorithms included in *ECGLAB*, developed by the group of João Luiz Azevedo de Carvalho at the University of Brasilia, DF, Brasil. Details about the algorithm are given in [Carvalho et al., 2002](Documentation/Articles/icsp2002_ecglab.pdf).
 - **Pan-Tompkin** implements the [Pan & Tompkins, 1985](Documentation/Articles/PanTompkins.pdf) algorith using the function `BioSigKit.PanTompkins()` that is distributed with the [BioSigKit toolbox](http://joss.theoj.org/papers/10.21105/joss.00671), developed by 
 [Hooman Sedghamiz](https://github.com/hooman650).
 

heplab.m

@@ -349,13 +349,15 @@
 hepgui.subm_fastdetect=uimenu(hepgui.subm_r_detect,'Label','ecglab fast',...
     'CallBack',	[...
     'HEP.qrs = heplab_fastdetect(HEP.ecg,HEP.srate);'...
+    'HEP.ibi = diff(HEP.qrs)/HEP.srate;'...
     'HEP.ecg_handle=heplab_ecgplot(HEP.ecg,HEP.srate,HEP.qrs,HEP.sec_ini,',...
     'HEP.ecg_handle,HEP.winsec);']);
 
 % slowdetect
 hepgui.subm_slowdetect=uimenu(hepgui.subm_r_detect,'Label','ecglab slow',...
     'CallBack',	[...
     'HEP.qrs = heplab_slowdetect(HEP.ecg,HEP.srate);'...
+    'HEP.ibi = diff(HEP.qrs)/HEP.srate;'...
     'HEP.ecg_handle=heplab_ecgplot(HEP.ecg,HEP.srate,HEP.qrs,HEP.sec_ini,',...
     'HEP.ecg_handle,HEP.winsec);']);
 
@@ -364,6 +366,7 @@
     'CallBack',	[...
     '[amp,HEP.qrs] = heplab_pan_tompkin(HEP.ecg,HEP.srate);'...
     'if size(HEP.qrs,1)<size(HEP.qrs,2); HEP.qrs = HEP.qrs''; end;'...
+    'HEP.ibi = diff(HEP.qrs)/HEP.srate;'...
     'HEP.ecg_handle=heplab_ecgplot(HEP.ecg,HEP.srate,HEP.qrs,HEP.sec_ini,',...
     'HEP.ecg_handle,HEP.winsec);']);
 
@@ -372,6 +375,7 @@
     'CallBack',	[...
     '[R,Q,S,T,P_w] = heplab_T_detect_MTEO(HEP.ecg,HEP.srate,0);'...
     'HEP.qrs = T(:,1);'...
+    'HEP.ibi = diff(HEP.qrs)/HEP.srate;'...
     'HEP.ecg_handle=heplab_ecgplot(HEP.ecg,HEP.srate,HEP.qrs,HEP.sec_ini,',...
     'HEP.ecg_handle,HEP.winsec);'...
     'clear R Q S T P_w']);