1

Biomedical Technology Department

College of Applied Medical Sciences

Salman Bin Abdul-Aziz University

NASSER AL-SOLIMAN

HASSAN AL-TAMIMI

AMER AL-KTHERE

Design of Electrocardiogram

(ECG) System

AbstractAbstract

• This research deals with the design of electrocardiogram (ECG) system that measures heart signals. The design is based on discrete electronics components that reduce the cost of the system. The system consists of 3-op-amp instrumentation amplifier, band-pass filter with bandwidth of 0.05Hz - 100Hz, mains frequency notch filter and a total gain of 1000. A stand alone split power supply is designed to power the system. The ECG system is tested using medical ECG electrodes and typical ECG signals were recorded from some volunteers.

Biomedical Technology Department College of Applied Medical Sciences Salman Bin Abdul-Aziz University

2

Research ObjectivesResearch Objectives

Biomedical Technology Department College of Applied Medical Sciences Salman Bin Abdul-Aziz University

3

Research ProblemResearch Problem

•Design and testing of ECG system using discrete components.

Biomedical Technology Department College of Applied Medical Sciences Salman Bin Abdul-Aziz University

4

Introduction to ECGIntroduction to ECG

The electrical activity associated with heart muscles travels through various tissues and reaches the surface of the body where it can be detected by electrodes applied to the skin. The record obtained from the depolarization and repolarization voltages of the heart muscle is called an electrocardiogram or ECG [1], [2].

Biomedical Technology DepartmentCollege of Applied Medical SciencesSalman Bin Abdul-Aziz University

5

ECG System SpecificationsECG System Specifications

• - Three Op-amp Instrumentation amplifier (IA) and an inverting amplifier with total gain of 1000.

• - Band Width 0.05 – 100 Hz (Low Pass Filter (LPF) and High pass Filter (HPF)).

• - Notch Filter centered at 60Hz.

• - CMRR =80 dB

Biomedical Technology Department College of Applied Medical Sciences Salman Bin Abdul-Aziz University

6

The project block diagramThe project block diagram

Biomedical Technology Department College of Applied Medical Sciences Salman Bin Abdul-Aziz University

7

ECG designed Power supplyECG designed Power supply

Biomedical Technology Department College of Applied Medical Sciences Salman Bin Abdul-Aziz University

8

Split Power Supply DesignSplit Power Supply Design

Biomedical Technology Department College of Applied Medical Sciences Salman Bin Abdul-Aziz University

9

Instrumentation Amplifier Circuit Instrumentation Amplifier Circuit Diagram Diagram

Biomedical Technology Department College of Applied Medical Sciences Salman Bin Abdul-Aziz University

10

Band Pass Filter circuit diagramBand Pass Filter circuit diagram

Biomedical Technology Department College of Applied Medical Sciences Salman Bin Abdul-Aziz University

11

A Notch Filter centered at 60 Hz.A Notch Filter centered at 60 Hz.

Biomedical Technology Department College of Applied Medical Sciences Salman Bin Abdul-Aziz University

12

Constructed ECG circuit Constructed ECG circuit

Biomedical Technology Department College of Applied Medical Sciences Salman Bin Abdul-Aziz University

13

ECG System setup and testingECG System setup and testing

Biomedical Technology Department College of Applied Medical Sciences Salman Bin Abdul-Aziz University

14

Research Research OutputsOutputs

1. An operating ECG system is designed and tested.

2. ECG signals were recorded and displayed.

Biomedical Technology Department College of Applied Medical Sciences Salman Bin Abdul-Aziz University

15

Biomedical Technology Department College of Applied Medical Sciences Salman Bin Abdul-Aziz University

16

ECG Signal Results Before the Notch ECG Signal Results Before the Notch Filter.Filter.

Biomedical Technology Department College of Applied Medical Sciences Salman Bin Abdul-Aziz University

17

ECG Signal Result After the Notch ECG Signal Result After the Notch FilterFilter

Biomedical Technology Department College of Applied Medical Sciences Salman Bin Abdul-Aziz University

18

CONCLUSIONS CONCLUSIONS

• The constructed single-channel ECG amplifier is capable of acquiring a satisfactory reading of rest ECG signal. It can be expanded to be a multi-channel ECG system capable of recording the standard 12-Lead system.

Biomedical Technology Department College of Applied Medical Sciences Salman Bin Abdul-Aziz University

19

• References

• [1] Bronzino, J.D., The Biomedical Engineering Handbook. CRC Press, Inc., 1995.

• [2] Carr, J.J. and J.M. Brown, Introduction to Biomedical Equipment Technology. Prentice Hall, Inc., 3rd ed., 1998.

Biomedical Technology Department College of Applied Medical Sciences Salman Bin Abdul-Aziz University

20