ECG signal baseline drift correction

19 views (last 30 days)
Sabaudian
Sabaudian on 3 Jun 2022
Commented: Mathieu NOE on 8 Jun 2022
I'm at the start of learning signal processing.
I'm trying to denoising this ECG signal using Wavelet Trasform to correct the baseline drift. This is my attempt, but I am very doubtful about it. I do not know if my attempt is correct or not (the signal does not seems so). I need an advice from someone more experienced than me, so in this way I can understand better and improve my work.
%--Load Real signal--%
load ('100m.mat');
RealECG = val/200;
Fs = 360; % Hz
L = length(RealECG); % Signal Length
TimeInterval = 10; % sec
T = linspace(0,TimeInterval,L); % time axis
%--Plot--%
figure (1); plot(T, RealECG); grid on;
title('ECG Signal'); xlabel('time (sec)'); ylabel('voltage (mV)');
%% Correction of the wandering baseline of the ecg signal
wv = 'db9';
[c,l] = wavedec(RealECG,8,wv);
nc = wthcoef('a',c,l);
rec = waverec(nc,l,wv);
figure(2); plot(T,rec); grid on;
title('WT Baseline Correction');
xlabel('time (sec)'); ylabel('voltage (mV)');
  1 Comment
Sabaudian
Sabaudian on 6 Jun 2022
Since nobody wants to reply, you can at least redirect me to some material that can clarify the concepts related to the Wavelet transorm and how to use it to correct the baseline

Sign in to comment.

Answers (1)

Mathieu NOE
Mathieu NOE on 7 Jun 2022
hello
a simple high pass filter suffices
%--Load Real signal--%
load ('100m.mat');
RealECG = val/200;
Fs = 360; % Hz
L = length(RealECG); % Signal Length
TimeInterval = 10; % sec
T = linspace(0,TimeInterval,L); % time axis
%--Plot--%
figure (1); plot(T, RealECG); grid on;
title('ECG Signal'); xlabel('time (sec)'); ylabel('voltage (mV)');
%% Correction of the wandering baseline of the ecg signal
% wv = 'db9';
% [c,l] = wavedec(RealECG,8,wv);
% nc = wthcoef('a',c,l);
% rec = waverec(nc,l,wv);
% some high pass filtering % baseline correction
N = 2;
fc = 1; % Hz
[B,A] = butter(N,2*fc/Fs,'high');
rec = filtfilt(B,A,RealECG);
figure(2); plot(T,rec); grid on;
title('WT Baseline Correction');
xlabel('time (sec)'); ylabel('voltage (mV)');
  2 Comments
Mathieu NOE
Mathieu NOE on 8 Jun 2022
ok - i will let someone else answer it , as I don't have this toolbox

Sign in to comment.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!