How can I write a filter code for my PPG signal to clear all noises on MATLAB?

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Runo Insan 2013-12-21

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评论： Richeek Dey 2017-2-16

Hi, I have my graphic like this. Firstly, I need to find peaks,but my signal is so noisy. How can I make my signal pure without any noise and holding orginal signals? Thank you.

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Wayne King 2013-12-21

We need to know the sampling rate of your data before we can recommend a filter. What does that time axis represent?

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Answer 1

Sunil Kumar Yadav 2014-4-8

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I am amazed that no one answered your question. You should use filter.I have used butterworth filter .matlab Command is butter.After making butterworth filter of desired order use filtfilt command to apply your filter to data which you want to process.Here is the example of bandpass filter W1=0.5/60;% lovver cutoff W2=4/60;%higher cutoff

[b,a]=butter(2,[W1,W2]); % Bandpass digital filter design h = fvtool(b,a); % Visualize filter

low_pass_data1 = filtfilt(b,a,intensity_r); % applying filter to our data intensity_r

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Sunil Kumar Yadav 2014-4-16

hey the cutoff frequencies should be w.r.t. half the sampling frequency.If Fs is sampling frequenvy then W1=(Low_Cuttoff)/(Fs/2);% lower cutoff frequency W2=(High_Cuttoff)/(Fs/2);% Higher cutoff frequency .Use [pks,locs] = findpeaks(data) ; to locate the peaks.

Richeek Dey 2017-2-16