Can I make the loop not count the t-waves in a ECG signal?

Hi, I have trouble making my matlab loop count only my R waves of the ECG signal. The loop counting the peaks is:

thr = 40;

beat_count = 0;

for k = 2 : length(sig)-1

   if( sig(k) > thr && sig(k-1) < thr) 

        beat_count = beat_count + 1; 

        id(beat_count) = k; 

    end

end

Some of the T-waves is the same height. I suggest making some sort of delay, so that the counter won't count until 0.3 seconds have passed since that is the maximum speed of the heart beats, and any peak within this time must be a t-wave. Can anybody help with this?

Answer 1

[Sandro Lecci]

Dear Maria,

Consider using the function findpeaks with the 'MinPeakDistance' argument (that works as a refractory period)

[pks,locs] = findpeaks(sig, 'MinPeakDistance', 300)

where 300 is 0.3 seconds with an hypothetical 1kHz resolution of your signal.

Best, Sandro