This project describes the design of a heart rate monitoring system using an mbed NXP LPC11U24 microcontroller and a heart beat sensor. The system measures the user's heart rate continuously and checks if it is abnormal. If an abnormal reading is detected, an alarm is raised. The system consists of a heart beat sensor, microcontroller, LCD display and other components like a temperature sensor. The heart beat sensor provides analog output of the heart beat which is read by the microcontroller through an ADC. The readings are displayed on the LCD and the system can send alerts in case of abnormalities.

1. B Y JIGYASA SINGH
M . T E C H ( E C E )
Health monitoring system
(using mbed NXP LPC11U24)

2. INTRODUCTION
This project work report describes the designing of Heart
rate monitoring system using mbed NXP LPC11U24 and
comparing the output with on the basis of its various
parameters. The basic structure include mbed
microcontroller and an analog heart beat sensor. The
Heart Beat Sensor is designed to provide analog output
of heart beat when a finger is placed on it. When the
Heart detector starts working, the top most LED will
starts flashing with every heart beat. In this project, the
device can continuously measure the heart rate & checks
for the abnormal condition (pulse below or above
normal).Whenever the device observes any unusualality
it raises an alarm at local level.

3. Evolution of electronic monitoring of health
Today’s electronic devices can be worn on wrist, legs, chest and
anywhere on body.
 Theses devices communicate wirelessly to smartphones applications or
other central programs.

4. Characterstics of a heart monitor
It allows to measure one’s heart rate in real time
or record the heart rate for later study.
It is composed of a sensor which can be analog or
digital.
The output is shown on lcd screen or any other
display.
Advanced versions offer measurements of heart
rate variability, activity, and breathing rate to
assess parameters related to health.

5. Block diagram of heart rate monitoring system

6. Detail of components
1. Heart beat sensor: The Heart Beat Sensor is
designed to provide analog output of heart beat when
a finger is placed on it. When the Heart detector
starts working, the top most LED will starts flashing
with every heart beat. The output of this sensor can
be connected to Micro Controller directly to measure
the heart beat. It functions on the principle of light
modulation by blood flow through the nerves of the
finger at every pulse. The module output mode,
analog output mode is simple.

7. Working of heart beat sensor
Connect gnd to ground ,
Vcc to +5v of any board
connect Out to any of the port
pins. Keep the finger in
between the phototransistor
and IR diode.Check the variation
in LED.It counts the number
of pulses.

8. 2. Microcontroller
 Following are the functions of microcontroller:
1. Reading sensor values through ADC (analog to digital
convertor)
2. Reading longitude and latitude from GPS modem.
3. Reading heartbeat and temperature values.
4. Displaying these values on LCD display.
5. Sending these values to modem so that SMS can be sent
to the Doctor or any authorized person in hospital.
6. To turn on buzzer when any of the sensor values cross
threshold level.

9. mbed Microcontroller
The mbed Microcontrollers are a series of ARM
microcontroller development boards designed for
rapid prototyping. The mbed NXP LPC11U24
Microcontroller in particular is designed for
prototyping low cost USB devices, battery powered
applications and 32- bit ARM® Cortex™-M0 based
designs. It is packed as a small DIP form-factor for
prototyping with through-hole PCBs, stripboard and
breadboard, and includes a built in USB FLASH
programmer.

10. Pin description of mbed NXP LPC11U24

11. 3.Other components
 Temperature sensor: To measure the body temperature of the baby.
This can be an analog type of temperature sensor. It gives variable output
voltage as per the variations in the temperature received / sensed.
 Amplifier: Since the output of temperature sensor is in millivolts. So we
may need amplifier to amplify this voltage.
 Analog to Digital Convertor: If microcontroller is not able to read the
analog signal or analog voltage.
 Buzzer: Buzzer can be used to give indication about the parameter
crossing a threshold value.
 Push Button: A push button can be there so that in case the person is
feeling uneasy, in pain or breathlessness then he himself or person near
him can manually press the button to inform others and get help.
 LCD display:LCD display is used to show messages like sending SMS,
SMS sent successfully. I have used 16×2 alphanumeric display. The person
can inform family member or the staff from hospital like ward-boy, nurse
or a doctor.

12. Connections for lcd interfacing with mbed

13. Working of heart rate monitoring system

14. Advantages & Applications
 Advantages:
1. It is fully automated system and does not require any
human attention.
2. Automatic alert system gives intimation to required
persons.
3. It provides a feature of remote monitoring of person’s
parameters. 5.
 Applications :
1. This project can be used in home for patients or ill
person or old person.
2. Same project can be used in hospitals.

15. Thank you..