MATLAB: How to write a filter code for the PPG signal to clear all noises on MATLAB

Question

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.

Answer 1

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