Electronic equipment used in hospitals include electrocardiographs, digital thermometers, ultrasound machines, and defibrillators. An electrocardiograph records and displays the electrical activity of the heart over time using electrodes placed on the skin. A digital thermometer uses a thermistor to sense temperature and displays the reading digitally. An ultrasound machine uses high frequency sound waves to produce images of internal organs. A defibrillator delivers a high-energy electric shock to the heart through paddles placed on the chest to restart the heart during cardiac arrest. These devices aid in diagnosing and treating patients.

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2. Submitted by:
Case Study
ECE 131
VARIOUS ELECTRONIC EQUIPMENTS
USED IN A HOSPITAL
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Submitted to:
Mr. Shiv Kumar,
Assistant professor

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4.  What is a Medical Device?
Medical device means any instrument, apparatus, machine, which is
designed by the manufacturer to be used, alone or in combination,
for human beings, for one or more of the specific medical purposes
of:
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5. Instruments seen in
hospital
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• Electrocardiograph
• Digital thermometer
• Ultrasound
• Defibrillator

6. • It is an electronic device which performs
electrogardiography.
Electrocardiography is the process of recording
the electrical activity of the heart over a period of
time using electrodes placed on the skin.
A normal heart beats 70 times a minute.
• Power use (110 – 230 V) .
• Battery (12V) .
• All results are shown as wave form on the screen
and those waveforms are printed in labels, which
gives the complete imformation of a person’s
heart.
Electrocardiograph
(ECG or EKG)

7. ECG of a heart in normal sinus mode
Cont.....
Electrocardiograph
(ECG or EKG)
ECG of a heart in normal sinus rhythm.

8. Cont.....
Electrocardiograph
(ECG or EKG)
Function blocks of an ECG
•There are total 12
Electrodes/Transducer, ten
electrodes are placed on the
patient's limbs and two on the
surface of the chest.
•These electrodes converts ECG
signal into electrical voltage.
•The surface of electrode contains
AgCl.
•Those voltage are fed to amplifier
to amplify the voltages.
•Opto-Coupler prevents high
voltages from affecting the system
receiving the signal.
•The frequency range of 0.04 Hz ~
150 Hz.
•Oscilloscope draws the waveforms
on the screen. It draws the graph of
voltage as a function of time.

9. • It is a device used to measure the temperature of any
particular device or living body and displays the
reading.
•A thermometer scale can be in Fahrenheit or Celsius.
Digital
Thermometer
Digital thermometers rely on the principle that the electrical resistance of metal changes with
temperature.

10. Cont.....
Digital
Thermometer
Components of Digital thermometer
• Battery : It has a button cell LR41battery made up of metal and provides around 1.5V supply to the
thermometer.
• Body: The body of the thermometer is made up of hard plastic and is 100.5mm long . Cap protects
the battery from being damaged.
• Thermistor : It is a semiconductor material made up of ceramic and is
used to sense the temperature. It is placed at the tip of the
thermometer and is enclosed inside a cap made up of
stainless steel.
• LCD :
It is15.5mm long and 6.5mm wide. It displays the reading
for 3 seconds and then starts flashing indicating the next
temperature to be measured.

11. Cont.....
Digital
Thermometer
Advantages of Digital Thermometers:
•Accuracy: The temperature reading doesn’t depends on scale reading and instead shown directly
on the display. Hence temperature can be read exactly and accurately.
•Speed: Digital thermometers can reach a final temperature in 5 to 10 seconds compared to
conventional thermometers.
•Safety: Digital thermometers don’t use mercury, hence the hazards of the mercury is eliminated in
case the thermometer breaks.
•Strong: The thermometer doesn’t needs to be shaken for the proper mercury level, hence the risk of
the tube getting broken is eliminated.

12. Ultrasound
• Ultrasound is type of imaging It uses high-frequency waves to look at
organs and structures inside body.
•These sound waves are reflected by tissue and images are produced on
the screen.
•It has its own CPU which processes all the data and gives supply to
transducer.
•Ultrasound devices operate
with frequencies from 20kHz
up to several gigahertz.
•Transducer probe is the main
part of ultrasound machine.
•It send the sound waves and
receive the echoes.

13. Cont.....
Ultrasound
Specifications of Ultrasound:
•Power input should be 220-240V A C .
•Monitor should be of 15” or more.
•High resolution colour monitor.
• Image resolution is less compare to CT and MRI scan.
• It has poor penetration through bone or air.

14. Defibrillator
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• A defibrillator is a device that gives a high energy electric
shock to the heart through the chest wall to the patient who is in
cardiac arrest.
• It is used in emergency conditions like when heart attack
occurs.
Principle of Defibrillator:
• Energy storage capacitor is charged at relatively slow rate from AC
line.
• Energy stored in capacitor is then delivered at a relatively rapid rate to
chest of the patient.

15. Cont.....
Defibrillator
Defibrillator Electrodes:

16. Cont.....
Defibrillator
Placement of Electrodes:

17. Cont.....
Defibrillator
The gel acts as a good conductor of
the electric current at the metal-skin
interface .
If we do not use this gel, then the
patient will get really bad burns at the
site due to high resistance offered by
the air between skin and paddle.

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