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Heart Frequency Graph Completed

This commit is contained in:
Thomas PÉRIN 2023-02-18 21:14:59 +01:00
parent b6c887f31e
commit e0eddd2d1e
1 changed files with 15 additions and 2 deletions
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17
heartRateEstimation.m
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@ -69,17 +69,30 @@ blueChannel_avg = mean(blueChannel);
blueChannel_std = std(blueChannel);
% normalize your data
for i=1:columns(greenChannel)
%first define length of our data
L = columns(greenChannel);
for i=1:L
greenChannel_normalized(i) = (greenChannel(i) - greenChannel_avg)/greenChannel_std;
end
% fft(greenChannel_normalized)
greenChannel_fft = fft(greenChannel_normalized);
% power spectrum (https://www.mathworks.com/help/matlab/ref/fft.html)
P2 = abs(greenChannel_fft/L);
P1 = P2(1:L/2+1);
P1(2:end-1) = 2*P1(2:end-1);
f = 15*(0:(L/2))/L;
plot(f,P1)
% find the peak in the range ([0.75 4] Hz)
% max -> value, index
low_index = 0.75*L/15+0.5
high_index = 2*L/15
a = max(P1(low_index:high_index))
heart_rate = f(a)
% convert the index from Hz to bpm
% determine heart rate