here we observe how we remove noise from ecg signal using matlab

1. 1. Debarati Mohanty – 1401298156
2. lora sahoo -- 1401298160
3. Sarada Priyadarsanee Patra -- 1401298162
4. Smruti Sangeeta Rout -- 1401298354

2. Abstract :-
 Electrocardiogram (ECG), a non invasive technique is
used as a primary diagnostic tool for cardiovascular
diseases.
 A cleaned ECG signal provides necessary information
about the electrophysiology of the heart diseases &
ischemic changes that may occur.
 It provides valuable information about the functional
aspects of the heart & cardiovascular system.
 ECG has been used extensively for detection of heart
disease.

3. Contd….
 ECG is non-stationary bioelectrical signal including
valuable clinical information , but frequency it is
corrupted by various kinds of noise.
 After a detailed comparative study about different
filters we selected an appropriate one.
 Our project is basically concentrated on noise removal
from the ECG signal using a special technique using
adaptive & S-G filter.

4. Content
 Introduction
 Project Workflow
 Capturing of ECG signal
 ECG generation
 Noise generation
 Adder block
 Adaptive filter block
 Savitzky-Golay filter
 Future scope

5. Introduction
 Electrocardiography is a transthoracic interpretation
of the electrical activity of the heart over a period of
time.
 ECG is used to measure the rate and regularity of
heartbeats, the presence of any damage to the heart , &
the effects of drugs or devices used to regulate the
heart.
 It is often affected by noise signals, the removal of
which is the main intention behind this project.

6. Project Workflow :-
ECG signal
generation
Noise signal
generation
ADDER
Digital Filter
(Adaptive Filter)
Savitzsky Golay Filter
(Smoothening Filter)
Output waveform
obtained

7. Capturing Of ECG Signal

8. Contd….
 SA node discharge no deflection.
 Right & Left atrial activation : P wave
 Activation of AV node & bundle of his : No deflection
 septal activation : Onset of QRS complex, initial
septal Q wave.
 Left ventricular free wall activation : inscription of
QRS complex.
 Full ventricular activation : No deflection
 Ventricular repolarization : His purkinje T wave
 Left ventricular repolarization : his purkinje U wave

9. ECG Generation
 Code Used :-
% load ecg : simulated noisy ECG
Fs = 500;
Z = repmat(ecg(Fs),1,8);
refer = randn(1,length(z)).*0.18+3/20;
x = z+randn(1,length(z)).*0.18;

10. Noise Generation:-
 Code Used:-
%plot noisy signal
subplot(5,1,1);
plot(x);
set(gca, ‘YLim’ ,[-1,1], ‘xtick’ , [])
title(‘noisy’)

11. Adder Block:-
 This block constitutes the mixing of the above two
signals.
 We have used additive mixing technique for this
purpose.

12. Adaptive Filter Block:-
Digital
Adaptive
d(n) = s(n)+ n(n) +
-
Y(n)=n’(n)
e(n)= s’(n)
X(n)

13. Savitzky-Golay Filter
 ECG signal can potentially corrupted by various types
of noises which lead to incorrect diagnosis.
 Many types of filters are available for filtering or
smoothing the noisy ECG.
 Some of them are not very much effective & some of
them destroy the characteristics of ECG signal during
filtering process. Savitzky-Golay(S-G) is one of the
filters which can smoothen out the signal without
much destroying its original properties.

14. Future Scope :-
The work presented in thesis can be extended to:
 To design better ECG signal coding to improve the
ECG signal compression.
 To explore better quantization techniques for
improvement in CR for ECG signal.
 To explore better design for hardware implementation
of ECG compression technique.