Converting beat-by-beat data into second average
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Hi,
I have a 30-minute recording of heart rate measured beat-by-beat (2003 samples), however i would like to have this dataset as averages of each second (1800 samples). I believe an interpolation of the data may be required but unsure how to acheive this.
Any help would be greatly appreciated!
Thanks.
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Answers (2)
Mathieu NOE
on 26 Oct 2022
hello
you can use smoothdata to smooth / average your curve then you do the interpolation to resample at dt = 1 second
nota that your original sample rate (0.8985 second) and the target one (1 second) are very close, so there are not many samples of data in a 1 second long buffer. I supposed that it was rather a matter of smoothing (but maybe I'm wrong)
t = TimeHR.Time;
y = TimeHR.HR;
dt = mean(diff(t)); % original rate
% smoothing using 'samples' length window
samples = 5;
ys = smoothdata(y,'gaussian',samples);
% interpolate to get 1 s time increment data
new_t = t(1):1:t(end);
new_ys = interp1(t,ys,new_t,'linear');
figure
plot(t,y,new_t,new_ys)
William Rose
on 26 Oct 2022
I have done this in Labview before but not Matlab.
Make a time series of HR versus time, where HR is computed as 1/(R-R interval), and the time of each HR esitmate is the midpoint time between the two RR intervals. Now you have two vectors of equal length : t_raw (unevenly sampled) and HR. Then make a time vector with the values t=(0,1,2,...), and use interp1() to interpolate the HR to the 1-second time vector.
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