how to contaminate ecg signal with noise

8 visualizaciones (últimos 30 días)
sai lakshmi
sai lakshmi el 16 de Nov. de 2019
Comentada: Daniel M el 23 de Nov. de 2019
I am working on the project namely "FALSE ALARM REDUCTION IN ATRIAL FIBRILLATION DETCTION USING DEEP BELIEF NETWORKS".
In this i need to download two databases, namely 07910m.mat{MIT_BIH ATRIAL FIBRILLATION DATABASE} which is attached here,and also the 'em' recording {MIT_BIH NOISE STRESS TEST DATABASE} is attached.
The afib database has Fs=250Hz and 10h in length,and 'em' recording is 30 min and has Fs=360Hz
now i need to make the 'em' recording 10h in length
in the paper its told that i can be done using auto regressive model,iam not knowing how to do it
can anyone suggest me the coding for thisscreenshot.png
  11 comentarios
Daniel M
Daniel M el 20 de Nov. de 2019
Well you know there will be a loop involved. Can you show me the code you currently have? I can help you get there.
sai lakshmi
sai lakshmi el 20 de Nov. de 2019
load('07910m.mat');
x1=(val(1,:))/200;
n=length(x1);
fs=250;
t=0:1/fs:(n-1)/fs;
%plot(t,x1);
%[qrs_amp_raw,qrs_i_raw,delay]=pan_tompkin(x1,fs,0);
load('emm.mat');
x2=(val(1,:));
Fs=360;
x3=resample(x2,25,36);
figure(1);
subplot(2,1,1);
plot(x2);
subplot(2,1,2);
plot(x3);
[d1,p1,rc] = aryule(x3,20);
for c=1:20
psi(c)=d1(c+1);
end
zmwn=randn(size(x1));
z=double.empty(0,1000000);
for i=1:length(x1)
z(i)=(-1.8909*z(i-1)+1.2973*z(i-2)-0.7229*z(i-3)+0.4524*z(i-4)-0.2636*z(i-5)+0.2620*z(i-6)-0.2307*z(i-7)+0.2164*z(i-8)-0.8175*z(i-9)+0.1536*z(i-10)-0.1285*z(i-11)+0.0878*z(i-12)-0.0736*z(i-13)+0.0682*z(i-14)-0.0679*z(i-15)+0.0487*z(i-16)-0.0268*z(i-17)+0.0249*z(i-18)-0.0153*z(i-19)+0.0026*z(i-20))+zmwn(b);
end
I am getting an error "subscript indices must be either of positive values or logicals"
I understood the occurence for error,but am not recognizing of how to simulate the noise signal in this.

Iniciar sesión para comentar.

Respuestas (2)

Daniel M
Daniel M el 20 de Nov. de 2019
Editada: Daniel M el 21 de Nov. de 2019
I obviously cannot run this code because I don't have the data nor any of the associated functions. By the way, you are getting an error because you are trying to access z at negative index locations.
Here is an example of how you would plot the equation. Keep in mind the assumptions I've made, which I've tried to comment.
clearvars
clc
sz = [1 1000];
e = randn(sz); % epsilon
X = nan(sz); % preallocate
X(1) = 0; % set first value. Don't know what this should be.
c = 1; % a constant, don't know what this should be
p = 5; % set the order of the model. Don't know what this should be.
% note that p cannot be greater than the iterating variable of the loop
% otherwise, it would try to access negative index locations
% So, either initialize your loop index at a value greater than 2 (and have the starting values of X)
% or do it this way, using increasing values of p, up to n-1
phi = rand(1,p); % your values of phi
for n = 2:sz(2)
ii = 1:min(p,n-1); % see the note above
sigma = dot(phi(ii), X(n-ii)); % sum of the products of the elements
X(n) = c + sigma + e(n);
end
  7 comentarios
sai lakshmi
sai lakshmi el 23 de Nov. de 2019
the values of X are recorded as infinity!
so thought it wouldn't work.
Daniel M
Daniel M el 23 de Nov. de 2019
Did you not see my response that phi must be << than 1? Did you even try it? It works.

Iniciar sesión para comentar.


sai lakshmi
sai lakshmi el 21 de Nov. de 2019
I have provided the databases at the top of the question as links,please check it once and provide me with the required coding.

Categorías

Más información sobre Measurements and Feature Extraction en Help Center y File Exchange.

Community Treasure Hunt

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

Start Hunting!

Translated by