Gprs Based Heart Rate Monitoring Devivce

GPRS BASED HEART RATE MONITORING

SYSTEM

Mr. Marimuthu .C Assistant Professor

Department of Electronics and Instrumentation

Karunya University

Coimbatore

Richu Rachel George

Department of Electronics and Instrumentation

Karunya University

Coimbatore

Abstract— The electrocardiogram is a test that records the

electrical activity of the heart .This can be used to study the

number and regularity of heart beats. So the study of ECG

waveform helps in easy diagnosis of heart diseases by finding the

abnormality in rhythm of heart rate. If one is a heart patient he

will have to depend on hospital regularly even if it is at a larger

distance from his home. If the facility to observe his ECG and

find number of heart beats is available at home it would be easy

for him. To facilitate this, a heart rate monitoring device using

lpc2378 is proposed. The ECG waveform can be observed in

graphical LCD interfaced with the kit. If any abnormality is

found in the number of heart beats then we alert the doctor using

the sim900 module interfaced with it.

Keywords- ECG; LPC2378; heart rate; real time; LCD128*6;.

I. INTRODUCTION

Due to changes in lifestyle the number of heart patients in

the world has increased a lot. Young and old alike die of heart

attack. So it is important for everyone to have a heart rate

monitoring system at home so that he can observe his heart

rate from home. There are several benefits for portable Heart

rate monitoring systems. They help in continuous and regular

monitoring of ECG signal from home itself instead of

travelling to hospitals and thus help in reducing medical cost.

Also if we transmit the result directly to the doctor who is at a

different place then it is possible for him to give his diagnosis

early and can help in emergency situations. Early diagnosis of

heart related problems help reduce the number of death due to

heart attack a lot. By researching the ECG features and regular

of the disease, we can make the early prediction to the

pathological change and prompt diagnosis. If arrhythmia was

detected earlier and first-aid measures are taken promptly,

most of patients may avoid dying. Therefore, long-time

recording electrocardiogram of patient has extremely

important clinical value. Most of the monitors available in the

market are of large size, more power consumption and not real

time. The main objective of the monitor introduced in this

project is as follows: it can monitor ECG in real time, display

the ECG waveform on graphical LCD; also it processes the

digital signal to find the number of heart beats, and sends out

alarm when exception is detected. The ECG monitoring

system with 8 bit or 16 bit MCU has some disadvantages, less

computing speed, low capacity of storage, lack of interaction.

So the processor used here is an arm processor which is a 32

bit RISC processor. This uses GPRS module to send alarm

information automatically when ECG signals are abnormal.

II. METHODOLOGY

A. Block diagram

In this project we develop a continuous heart rate

monitoring system which acquire ECG signal from cardiac

patient and analyzed for any change in abnormality. If any

abnormality is found then it alerts the doctor who is at a

remote site of the patient condition. The block diagram of the

system is as given below.

Fig.1 Block diagram for heart rate monitoring system

Different types of electrodes are available commercially.

We use three ring electrodes to acquire signal from body. ECG

signal is a kind of body signal with 0.05Hz to 100Hz

bandwidth and about 1 mV peak to peak voltage, and mixed

with noise. As the ECG is usually in the 0.05-100Hz

frequency, the signal we acquired is also subject to high

frequency and low frequency noise. So output ECG signal

must be through a band-pass filter. This band-pass filter

consists of a high-pass filter and a low-pass filter in series

form. The output of this stage is also in mV range, a second

level amplifier is also used to raise the signal to around 1V.

These processes are done in the bio kit we use to acquire

signal.

The controller we use is LPC2378 which has an arm7

core (32 bit). This also has an inbuilt A/D convertor which can

be used to convert the ECG wave we obtained to digital form.

The ADC in the LPC2378 controller has input range of about

0V-3.3V .The signal from the bio kit is in this range and so is

given directly to the ADC.

The processor calculates the heart beat from ECG wave

form by finding the RR interval of the ECG signal. R wave

being sharp, narrow and steep, is most sensitive one and any

International Conference on Emerging Technological Trends in Advanced Engineering Research [ICETT 2012], 2012 February 20-21.

ISBN : 978-93-80624-62-4 http://www.icett.com/ Baselios Mathews II College of Engineering, Kollam, Kerala, India.

irregularity will instantly reflect on it .In order to find the time

interval between to r wave focus is on upper half of r wave.

The program is written to calculate heart rate in bpm.

Beats per minute (bpm) = 60000 (1)

Time between two RR waves

From the obtained value the possibility of heart attack is

analyzed. The heart rate for normal person is 60-100 so RR

interval is from 600-1000. If this range differs it declares a

panic situation.

Once panic situation is declared, the system will send alarm

information via GPRS module automatically thus alerting the

doctor of any abnormality. The system is also connected to an

LCD module so as to display the waveform acquired. The

patient can observe the ECG waveform himself.

LPC2378 ARM7 CONTROLLER

The LPC2378 Micro-controller is based on a 32/16 Bit

ARM7TDMI-s CPU with real time Emulation and Embedded

Trace support that combines with the microcontroller with

embedded high-speed 512KB flash memory. It can work with

16-bit Thumb Mode. This microcontroller incorporate a

10/100 Ethernet MAC, USB 2.0 Full Speed interface, four

UARTs, two CAN channels, an SPI interface, two

Synchronous Serial Ports (SSP), three I2C interfaces, an I2S

interface, and a Mini Bus. It has 8-bit data/16-bit address

parallel bus is available.

SIM900 GSM/GPRS MODULE:

This is a GSM/GPRS-compatible Quad-band cell phone,

which works on a frequency of 850/900/1800/1900MHz and

which can be used not only to access the Internet, but also for

oral communication (provided that it is connected to a

microphone and a small loud speaker) and for SMSs.

Externally, it looks like a big package (0.94 inches x 0.94

inches x 0.12 inches) with L-shaped contacts on four sides so

that they can be soldered both on the side and at the bottom.

Internally, the module is managed by an AMR926EJ-S

processor, which controls phone communication, data

communication (through an integrated TCP/IP stack), and

(through an UART and a TTL serial interface) the

communication with the circuit interfaced with the cell phone

itself.

The processor is also in charge of a SIM card (3 or 1,8 V)

which needs to be attached to the outer wall of the module.

In addition, the GSM900 device integrates an analog interface,

an A/D converter, an RTC, an SPI bus, an I²C, and a PWM

module. The radio section is GSM phase 2/2+ compatible and

is either class 4 (2 W) at 850/ 900 MHz or class 1 (1 W) at

1800/1900MHz. The TTL serial interface is in charge not only

of communicating all the data relative to the SMS already

received and those that come in during TCP/IP sessions in

GPRS (the data-rate is determined by GPRS class 10: max.

85,6 kbps), but also of receiving the circuit commands (in our

case, coming from the PIC governing the remote control) that

can be either AT standard or AT-enhanced SIMCom type.

The module is supplied with continuous energy (between 3.4

and 4.5 V) and absorbs a maximum of 0.8 A during

transmission.

OGM12864 LCD

We use 128*64 pixel graphic LCD for displaying the

ECG wave form. The graphic LCD is used to display

messages in form of drawings and bitmaps. The OGM12864

LCD is driven by 2 64 x 64 pixel Samsung KS0108 drivers.

There are 8192 pixels on a 128 X 64 pixel screen and each is

pixels is control by a series of instructions. The process of

selecting where on the screen the bit is going to go is just a

narrowing process. CS1 and CS2 narrow it down to half the

screen. Y address narrows it down to a 1 bit wide stripe of

height 64 in that half of the screen. X page picks an 8 bit

chunk of this 64 bit stripe and write data writes 8 bits to that

chunk. This is the essence of putting bits on the screen.

III. RESULTS AND ANALYSIS

Using ring electrode and Biokit ECG signal is

acquired. The ECG voltage was found around 1.44 Vpp and

the frequency of the signal around 1.01 Hz. Since the ECG

waveform from the kit is of 1.6 V it can directly be given to

ADC pin of the processor.

There are 8 channels available in the lpc2378 for

ADC. To configure the ADC we need to first set PCADC bit

in PCONP register. In the PCONP register, set bits PCADC.

Clock: In the PCLK_SEL0 register, select PCLK_ADC. To

scale the clock for the ADC we use CLKDIV. Select ADC

pins and pin modes in registers PINSELn and PINMODEn. To

enable interrupts in the ADC. The bits in ADCR register

should also be set accordingly.

The values from ADC was plotted on LCD .The

contrast of the LCD can be adjusted using potentiometer. The

most important (or most commonly used and confused)

control bits are R/W, D/I, E. Enable must be set low and then

high in order for an operation to be passed to the LCD. In

addition there must be a delay of at least 2 ms in between

operations for the cycle time of the enable bit. This timing can

cause lot of errors because if it is not delayed properly, a good

instruction will not provide the desired result. R/W and D/I are

used to determine the mode of operation that the LCD is in.

There are three basic steps that must be done in order to

determine where the pixels will go. First, the Y address must

be set. The Y address actually has a counter so it need only be

set once and then every time there is a data write it will be

incremented to the next line. This allows the driver to scan

through the lines and display the proper data. The next step

that must be completed is setting the X page. This determines

which column of the screen will now be written to. The third

step is issuing a data write command. Whatever data bits are

high will be darkened on the Y address line in the X page.



The SIM900 module is connected to the ARM

processor using UART. The communication is enabled using

AT command. The heart rate found if less than 60 or more

than 100 shows that there is arrhythmia, and hence alert the

doctor by sending SMS using the module.

The flow chart for the complete process is as below

As we need to display ECG wave form and calculate

heart rate at the same time we need to do multitasking. This is

made possible by using μCOS-II. μCOS-II is a portable, ROM

able, scalable, preemptive, real-time deterministic multitasking

kernel for microprocessors, microcontrollers and DSPs,

written mainly in the C programming language. It is intended

for use in embedded systems. To start we first declare each

task as standard C function and give a task ID for each task.

Next we enter application through main function and we call

function to start operating system. After operating system has

been initialized the control is passed to the task. When task is

created it is also assigned priority. As we need to run both the

task at the same time each task are given the same priority.

This also provides for task management and time

management. The most basic of timing service provided is to

have system delay. A task is similar to procedure call, but a

task must contain a while loop, once started it never terminates

and runs forever. By making use of this we can continuously

acquire signal to calculate the number of heart beats and also

display ecg waveform for patient to observe.

IV. CONCLUSION

The development of heart rate monitoring system

using LPC2378 helps in monitoring ECG waves in real time.

As we are using an ARM7 processor which supports μCOS-II

multitasking is possible. This helps in continuous evaluation

of ECG wave form along with displaying the wave. The ECG

wave form is to be displayed on LCD module. Also we are

using a GPRS module to alert the doctor of any abnormality in

the patient. As GPRS uses packet switching rather than circuit

switching we need to pay only for the amount of data we are

transmitting. We can alert the doctor using SMS.

REFERENCES

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[3] Xiuxia Yu , Kebing Wu , Zhengxiong Hou “Design and Implementation of ECG Wireless Transmission System Based on ARM9”, 2010 International Conference on Computer Control and Electronic Engineering ,volume:5, pp:211-213, 25 October 2010

[4] Tang Yawei,Jiang Kai,Fu Xiuquan,Li Dingli “Low Power dual-core Holter Systerm Based on MSP430 and ARM7” 3rd International conference on Bioinformatics and Biomedical Engineering, ,pp:1-3, 11-13 June 2009

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[6] Fan Aihua, Bian Chunhua, Ning Xinbao, He Aijun, Zhuang Jianjun, “Portable electrocardiogram monitor based on ARM” International Conference on Information Technology and Application in Biomedicine, China,pp:481-483, 18 July 2008



[7] Mohamed Fezari, Mounir Bousbia-Salah, and Mouldi Bedda” Microcontroller Based Heart Rate Monitor” The International Arab Journal of Information Technology, Vol. 5, No. 4, pp:153-157, October 2008

[8] M Triventi, E Mattei, F Censi, G Calcagnini, F Mastrantonio, D Giansanti, G Maccioni, V Macellari, P Bartolini” SMS-Based Platform for Cardiovascular Tele-Monitoring” Computers in Cardiology issue:35;pp:1009−1012,nov 2008

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Gprs Based Heart Rate Monitoring Devivce