We , in this project are measuring the heart beat using the pulse oximetry logic. The timer we have set for counting the heart beat is 30s. There is a set point we can decide, after 30 s the heartbeat would be shown on the LCD along with a buzzer sound (if it exceeds the set point).

1. Submitted By:
Sushil Kumar Mishra (05311502809)
BVCOE, New Delhi-63
1
BHARATI VIDHYAPEETH’S COLLEGE OF ENGINEERING
A-4, PASCHIM VIHAR, ROHTAK ROAD, NEW DELHI- 110063
AFFILIATED TO
GURU GOBIND SINGH INDRAPRASTHA UNIVERSITY, DELHI-1100006
(2009-2013)

2. Heart beat monitor
2
 A heart rate monitor is a
personal monitoring
device which allows one
to measure his or her
heart rate in real time or
record the heart rate for
later study. It is largely
used by performers of
various types of physical
exercise.
 Widely used in hospitals
for checking the health of
patient(s)Fig. 1 Wrist band for calculating heart beat

3. Why Monitoring……?
3
 More than 2 million people are at high risk of
having heart attack.
 It would be helpful if there was a way for these
people to monitor their heart.
 So we have a problem. That is the way our project
focuses on how we can utilize this problem and
find a solution.

4. Measurement of Heart rate
4
• Stethoscope ---
inaccurate
• Electrocardiogram –
costly
& not user friendly

5. Average Heart Rate
5
Average Heart RateAge
140Newborn
85 – 907 years
80 – 8514 years
70 – 80Adult

6. Microcontroller and why
Microcontroller not
Microprocessor?
6
• A microcontroller is a single-chip microcomputer which
contains RAM , ROM , CPU , I/O ports , ADC and other
peripherals.
• It has fixed amount of RAM , ROM , I/O ports.
• It is also called embedded microcontroller because it is
designed for embedded systems performing specific
tasks only.
• Microprocessor only has CPU , ALU, stack
pointer, program counter and other registers ,clock
timing circuit.
• Microprocessor does not have RAM, ROM and I/O
ports
• It requires large space and it’s cost is higher as compared
to microcontroller.

7. Embedded systems
7
 An embedded system is a
computer system designed for
specific control functions within a
larger system, often with real-time
computing constraints.
 It is embedded as part of a
complete device often including
hardware and mechanical parts.
 By contrast, a general-purpose
computer, such as a personal
computer (PC), is designed to be
flexible and to meet a wide range
of end-user needs.
 Embedded systems control many

8. What we have done? ? ?
8
 We , in this project are measuring the heart beat
using the pulse oximetry logic.
 The timer we have set for counting the heart beat
is 30s.
 There is a set point we can decide, after 30 s the
heartbeat would be shown on the LCD along with
a buzzer sound (if it exceeds the set point).

9. What we have used ? ? ?
9
 We are using an AT89S52 microcontroller for this
project
 A transformer for stepping down the voltage.
 Full wave rectifier for conversion of AC to DC.
 7805 voltage regulator to give a 5v dc voltage.
 An LM324 IC which is used as three stage trans
impedance amplifier in this board.
 LCD showing the heart beat
 A buzzer which will be activated when heart beat
exceeds set point.

10. Software we used ? ? ?
10
 KEIL uVision3 IDE
 SPI flash programmer

11. AT89S52
11
Atmel AT89S52 is a powerful
microcontroller which provides
a highly-flexible and cost-
effective solution to many
embedded control applications.
It is programmable compatible
with 8051 uc.

12. Pin diagram
12

13. 13

14. Top view of our project
14

15. Hardware implementation
15
 Transformer
 Full wave rectifier
 7805 voltage regulator
 Buzzer
 LM324
 Potentiometer
 LED + LDR used as sensor
 LCD
 Circuit diagram of project

16. Transformer
16
 Centre tapped transformer.
 9-0-9 v at the output.
 Rating of 1A current.
 It is centre tapped to have
both
-ve and +ve half cycle of AC
waveform to contribute to
direct current.
 Transforming energy using
mutual induction.
 TTL logic circuitry can not
work on voltage of 220v so we
are stepping down it to 9v

17. Full wave rectifier
17
 Converting both polarities
of input ac voltage to one
of the constant polarity at
its output dc current.
 Yields a higher mean
output voltage .
 Our circuitry can only
work on dc voltage.

18. LM7805-VOLTAGE
REGULATOR
18
 It has 5V Regulated output
voltage.
 Input voltage range:- 5V-
18V
 The voltage source in
circuit may have
fluctuation and would not
give fixed output voltage.
 Pin1-input ,Pin2-
ground, Pin3-output
 Heat sink is used for
dissipating heat into
surrounding air to protect

19. Buzzer
19
• A buzzer or beeper is
an audio signaling device, which
may
be mechanical, electromechanical, or
piezoelectric.
• Typical uses of buzzers and beepers
include alarm devices, timers and
confirmation of user input such as a
mouse click or keystroke.
In this project , we are using for the case in which the
measured HEART BEAT RATE passes the set point.

20. LM324
20
 This consist of four independent high-
gain frequency-compensated operational
amplifiers that are designed specifically
to operate from a single supply over a
wide range of voltages.
 Operation from split supplies also is
possible if the difference between the
two supplies is 3 V to 32 V (3 V to 26 V
for the LM2902), and VCC is at least 1.5
V more positive than the input common-
mode voltage.
 The low supply-current drain is
independent of the magnitude of the
supply voltage.

21. Uses of LM324
21
• Applications include transducer amplifiers, dc amplification
blocks, and all the conventional operational-amplifier circuits that
now can be more easily implemented in single-supply-voltage
systems.
• For example, the LM124 can be operated directly from the standard
5-V supply that is used in digital systems and provides the required
interface electronics, without requiring additional 15-V supplies.

22. Pulse oximetry logic
22
 We monitor the heart beat by pulse oximetry
technique. In this project we use innovative
technique to measure the heart beat
measurement. This is achieved by pulse oximetry
logic. We use this technique to get the pulse from
body and to amplify the signal and display this
data on the LCD .
 The light emitted from the LEDs were transmitted
through the skin and detected by light dependent
resistor. LDR were then connected to a amplifier
that converted the current to an appropriately-
enhanced voltage signal.
 Change of signal is further converted into pulse
.We count the pulses with the help of the
AT89S52 microcontroller.

23. Heartbeat measurement
using LED-LDR sensor
23
 Finger is illuminated by red light
being emitted by red led.
 When heart will expand then there
will be more blood in blood vessels
as a consequence more absorption
of red light will occur and lesser
amount of red light will fall on
LDR, decrease in resistance of LDR
will be less and large current will
through LDR.
 When heart will contract then there
will be no blood in blood vessels as
a consequence no absorption of red
light will occur and full amount of
red light will fall on LDR, decrease
in resistance of LDR will be large
and small current will through
LDR.

24. 24

25. Circuit diagram
25

26. HOW ? ? ?
26
 Transformer steps down 220V to 9-0-9V.
 Full wave rectifier converts the ac into dc.
 7805 voltage regulator regulates the voltage to
5V, which is the operating voltage of our
microcontroller.
 LCD is interfaced with microcontroller.
 LED - LDR sensor is used to count the Pulses.
It consists of a red LED and LDR .
 Crystal (11.059MHz) is used to generate a
stable clock signal for the microcontroller.

27. HOW ? ? ?
27
 Pin 9 is used as the reset circuit pin.
 LM 324 is used as a three stage trans
impedance amplifier.
 LEDS are used to indicate the supply, and
counting of heart beat.
 There is a buzzer on the board which will be
activated if the measure heart beat exceeds set
point.
 Code is burnt on the controller using SPI
programmer.

28. What is happening on-board
?
28
 Transformer is making the ac voltage 220 volt to
step down to 9-0-9 volt ac.
 Full wave rectifier is rectifying that voltage to get
larger average dc voltage.
 7805 is regulating the output voltage to 5v.
 Sensor consist of red LED and LDR is
generating the output signal inversely
proportional to absorption of red light caused by
blood.
 Transimpedence amplifier is converting current
signal to voltage signal ,amplifying signal and
change in signal and also filtering the signal also.

29. Contd..
29
 Microcontroller is counting the no of pulses using
counter T0 within 30 seconds of timer T1. It also
lets the user to set the average pulse rate with
which it will compare and make buzzer to sound if
it found deviation.
 Microcontroller is displaying the result i.e pulse
rate on LCD on which patient can see his heart
beat.

30. LED – LDR sensor
30
LED LDR

31. project
31

32. PCB back side diagram
32

33. Board back side photo
33

34. Applications
34
• Have become a widely used training aid for a
variety of sports.
• Hospitals / Dispensaries
• Better and accurate method of measuring heart
beat.
• At homes
• A set point can help in determining whether a
person is healthy or not checking his/her heart
beat and comparing with set point.

35. 35
• In-accurate method of calculating heartbeat.
• Logic used in very simple. Therefore, results may
vary as for a sophisticated instrument for the same
purpose

36. • EEG, ECG and other health parameters can also
be monitored.
• Continuous monitoring and future diagnosis can
be performed via the same system
(TELEMEDICINE).
• More than a single patient at different places can
be monitored using single system.
36

37. Any Queries ? ? ?
37