Automatic ECG peak detection with FFT

Hi everyone,

I am trying to do an automatiuc detection of Hearth Rate with ECG sample.

I try to use FFT and IFFT, and a FIR filtered to eliminate low frequencies (50Hz) but after, I can't detect peaks of the signal.

I need to find locals maxima of my set of data but I don't know how to do that.

I will be grateful if you can help me with this problem.

load ECG109;
ECG = ECG109;


fresult=fft(ECG);
fresult(1 : round(length(fresult)*5/Fe))=0; 
fresult(end - round(length(fresult)*5/Fe) : end)=0;
corrected = real(ifft(fresult)); % IFFT

% Low frequencies filter (50Hz)
Fn = Fe/2;
FIR = fir1(48,[49.7 50.3]/Fn,'stop');
ECG_filtered = filter(FIR,1,corrected);
subplot(2,1,1)
plot(ECG_filtered)
ECG_filtered

peaks = findpeaks(ECG_filtered,'DoubleSided')

[Cris LaPierre]

There's somethign wrong with you mat file. I get the following error when I try to load it.

Error using load

Unable to read MAT-file C:\Users\...\ECG109.mat. Not a binary MAT-file. Try load -ASCII to read as text.

Answer 1

[Cris LaPierre]

Do you have the Signal Processing Toolbox? If so, look into the findpeaks function.