CODEWITHSUNDEEP
matlab
Kenae
Kenae

Reputation: 59

Heart BPM Normalization - Matlab

I have two .wav files containing recordings of two different hearts so with different heart rates. I would like to normalize both signals in order to fix their BPM at 60 without modifying anything else.

This is how a signal is read (same thing for the other but with 2) and what it looks like (and it's FFT) :

[y1,fs1] = audioread(heartbeat1);
    N1 = length(y1);
    t1 = linspace(0, N1/fs1, N1);

enter image description here I made some research and found interp1 but it doesn't seem appropriate for my program. I really have no idea of how I could do that, so if you can just give a function that I could use it could be great.

Upvotes: 0

Views: 285

Answers (1)

shamalaia
shamalaia

Reputation: 2351

I am not sure I understood.

I think you want to compare two heart beat signals with different "principal" heart beat frequencies. So I think you can plot the two signals as function of

f / f_{beat}

where f_{beat} is the heart beat frequency of a signal. This will be an adimensional (it has no units,because 1/s / 1/s = 1) frequency and should permit you to compare signals with different heart beat frequencies because it does not distort it.

This is more or less the effect of what I propose. Note that I do not know to calculate the heart beat frequency and I just used f_{beat}=0.8 1/s. Probably you can improve that.

Signal as function of frequency:

enter image description here

Signal as function of the adimensional frequency:

enter image description here

Hope this helps somehow.

Upvotes: 1

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