Expt.4 To Generate Ecg Signal Using Labview 4u5e6y

Department of AE&IE

Biomedical Instrumentation Laboratory (Experiment 4)

EXPERIMENT NO.4 AIM: To generate simulated ECG signal using LabVIEW. I. II. III.

With Noise Without Noise Adjust its parameters

APPARATUS REQUIRED: PC, LabVIEW 8.5. THEORY: ECG is the electrical activity associated with functioning of the heart. ECG is quasi periodically, rhythmically repeating signal synchronized by the function of heart which acts as a generator of bioelectric events. Human heart is divided into four chambers i.e. atrium (right &left) and ventricle (right &left). FUNCTION OF HEART: Right atrium receives deoxygenated blood from veins and pumps into right ventricle. Right ventricle pumps blood into the lungs where blood is oxygenated. This oxygenated blood enters left atrium and pumps into left ventricle. This left ventricle pumps the oxygenated blood into different parts of body. The P waves, QRS complex and T wave reflects the rhythmic electrical depolarization and repolarization of myo-cardium associated with contraction and relaxation of atria and ventricles. NORMAL VALUES PARAMETERS:

OF

AMPLITUDE

AND

DURATION

OF

IMPORTANT

P-wave=0.25mV; R-wave=1.6mV; Q-wave=25% of R wave; T-wave=0.1% of Q wave to 0.5V

DURATION OF NORMAL VALUES:    

PR interval -0.1 to 2.2 seconds QT interval - 0.35 to 0.44 seconds ST interval – 0.05 to 0.15 seconds P segment or P wave interval – 0.11 seconds

Mahant Bachittar Singh College of Engineering and Technology

10

Department of AE&IE

Biomedical Instrumentation Laboratory (Experiment 4)

1. The PR and PQ interval measured from the beginning of P wave consecutive of R and Q wave respectively. It marks the time that an impulse take to reach ventricles. 2. QRS interval represents the time in which heart impulse travels through inter-ventricular system. 3. QT interval is period of 1 complete ventricular contraction. 4. P wave represents repolarization of both ventricles. 5. P waves occur due to depolarization of atrial. 6. QRS complex is a result of atrial repolarization and ventricular depolarization simultaneously. 7. T-wave is due to ventricular repolarization. BLOCK DIAGRAM:

Front (out put)

Block diagram(input)

Fig.4.1: Simulated ECG signal. PROCEDURE: 1. 2. 3. 4. 5.

Open LabVIEW 8.5. Select blank VI. Press ctrl+T to open the front and Block diagram window of VI. Right click on block diagram window to open the LAB VIEW tool menu. Go to biomedical application, select bio signals select the generation option and select simulated ECG signal.

Mahant Bachittar Singh College of Engineering and Technology

10

Department of AE&IE

Biomedical Instrumentation Laboratory (Experiment 4)

6. Drag and drop simulated ECG block in the block diagram window. This option opens parameters s for simulated ECG signal. 7. Adjust parameters like: a. Heart rate in bpm. b. PQRS wave action duration c. QRST duration 8. Deselect add noise option. 9. To view graph, right select on data in the simulated ECG block and select create, to create a graph indication. This creates a graph in front of VI. 10. To put the simulated ECG in infinite loop, right click on block diagram window. Select programming in LAB VIEW box tool menu. 11. Select structure option & in structures select while loop. 12. Right click to create a control for while loop. 13. Double click on simulated ECG block on block diagram window. This opens the parameters for simulated ECG signal. 14. Select add noise option to add noise to ECG signal. 15. Run the program to view the ECG signal in front graph indicator. RESULT: The desired simulated ECG signal has been produced using LabVIEW for both with and without noise.

Mahant Bachittar Singh College of Engineering and Technology

10