peaks detection in a smoothed processed signal

i have a homework in biosignal procesing course which about processing ecg signal and count peaks

i applied some codes and i reach until the point shown in the photo

now i need a way to count these peaks without using the findpeak() function

i am really stuck at this point...

any help?

Answer 1

[Image Analyst]

Try this (requires Image Processing Toolbox):

threshold = 2e-5; % for sqauring or 200 for "original signal".
mask = signal > threshold;
% Some peaks may have some "thickness" so find the centroid, or weighted centroid of the peak
props = regionprops(mask, signal, 'Centroid', 'WeightedCentroid', 'MaxIntensity');
indexesOfPeaks = vertcat(props.Centroid)
indexesOfWeightedPeaks = vertcat(props.WeightedCentroid)
% Get value of the very highest point in the thresholded signal.
peakValues = [props.MaxIntensity]
% Find indexes of where that highest peak occurs.
for k = 1 : numel(peakValues)
    indexOfPeaks2(k) = find(signal == peakValues(k));
end

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[mohammad yaman habra]

thank you