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International Conference on Electrical Electronics and Communications-ICEEC-21st June 2014-ISBN-978-93-81693-66-03
87
WEB SERVER NETWORK FOR ECG RECORDING AND BODY
TEMPERATURE MONITORING SYSTEM BASED ON ARM
MICROCONTROLLER
SHRUTHI G. B
1, NAVEEN H
2, PRIYA R SANKPA
3
1Ug, BNMIT,
2Asst Prof, MSEC,
3Asst Prof, BNMIT
Abstract: Recent development of Biomedical application like ECG recording and body temperature monitoring system for
time saving and low cost products are focused most . In this report we using a system based on web server network (WSN)
for recording ECG data and monitoring body temperature using ARM Microcontroller. The report describes continuous
recording of ECG signal on to web server and also displayed on on-board LCD display on MCU unit. It also describes Body
temperature monitoring system. Low voltage ECG signal from the electrode is Amplified by Instrumentation amplifier(INA)
and converted to digital values using ADC1298 . The acquired ECG signal are converted to specific format using ARM
MCU and recorded continuously in web server. The recorded ECG graph can be seen at any place using secured web
network.
Keywords- ECG,ARM MCU,ADC1298, INA ,LCD,WSN
I. INTRODUCTION
In recent years there has been increasing demands in
Biomedical area . To evaluate the performance of
cardiovascular system, continuous recording of
patient’s ECG is needed and also monitoring body
temperature of patient’s is required. A System which
has both ECG recording and Body temperature
monitoring interfaced with web server might help to
increase the comfort of patient and also it might
improve the leaving standard of the patient. The
detailed structure of project is given in Figure 1.
Figure 1: Structure of our project
There were many research which are carried on ECG
recording and increasing cardiovascular disease like
heart attack due to time and resource constraint
which motivated to carry out our work which give
precaution even better than the work which were
proposed in earlier research.
Most of the deaths due to heart attack are because of
less monitoring of patient’s who are at potential risk.
Wearable ECG device to record ECG data on to SD
card storage[1] inspired us to improvise it by using
web sever network to record ECG data.
The project aim is to reduce cost and to increase the
performance by using web server interface in place of
any other wireless device like Zigbee or Bluetooth.
.
A. Technical Background
Wearable ECG recording and Monitoring device
based on MSP430 MCU [1][2] was previous work
carried where amplified ECG data converted to
specific format by MSP430 to store in SD card.
Limitation of this work was unnecessary usage of
resource and time constraint.
In the research work of Wireless body area sensor
network [3] tiny wireless sensor network were placed
on the human body any vital sign can be monitored
by the user and personal. Limitation of this work is
limited range of wireless sensor network.
Our project uses resource efficient design and range is
also not limited as compared to WBAN research work
B.Proposed Solution
The simple solution is proposed in our project which
overcomes the limitation of the previous work.
The wearable ECG recording system to SD card is
extended to web server network where ECG data is
monitored on LCD display and also continuously
recorded into web server where time and resource are
efficiently utilized.
At remote place we can monitor the ECG data which
solves the range limitation of WBAN network. The
Top level block diagram of proposed work is given in
Figure 2
Our Project
Patient System Server system Doctor system
ECG Recorder Body temperature
Monitor
Web server network for ECG Recording and Body Temperature Monitoring System based on ARM Microcontroller
International Conference on Electrical Electronics and Communications-ICEEC-21st June 2014-ISBN-978-93-81693-66-03
88
Figure 2: Top level Block diagram
C. Organization of the Paper
Organization of the paper is as follows : System level
block diagram and detailed description about the
proposed solution are discussed in Section II ,
hardware and software implementation of our project
are given in Section III , results snapshots and test
trials are discussed in section IV , Conclusion and
future scope given in section V.
II. PROPOSED SOLUTION
The system-level block diagram of our project with
signal flow is as shown in figure 3
Figure 3 : System level block diagram
The hardware and software components used in our
design are ECG Electrodes and body temperature
sensor which are weak analog signals in mv, Theweak
signal is converted into strong signal by using
instrumentation amplifier (INA123). For processing
of data in Microcontroller unit, the analog signal
ouput from INA123 is converted to digital data using
instrumentation ADC IC i.e ADS1298.
Using microcontroller LPC1298 ARM 7 TDMI the
digital ECG data converted to specified format and
monitoring on LCD display and the same data is
processed into server system and the real time ECG
graph for three electrode and the body temperature of
patient is displayed. ECG data which is recorded into
system can be viewed by patient using there secured
ID and passwordprovided and also authenticated
doctor can view the details of the patients,ECG plot
and body temperature reading can be analyzed easily.
ECG signals are measured with button type ECG
electrode it uses AG/Agcl sensor element which has
best sensitivity and solid conductivity .Adhesive
hydrogel has very low impedance and is non irritating.
Body temperature signals are measured with
temperature sensor TMP36 it is very similar to LM35
temperature sensor.
The ECG signals which come from electrodes are
1mv peak to peak . An amplification is required for
suitable heart rate detection . Best approach is to use
differential amplifier like Instrumentation amplifier
INA123 . The device is operated at 2.7v. INA
provides fixed amplification of 5x for ECG signal.
The output of Instrumentation amplifier is analog
need to be made digital for processing of ECG data in
MCU .MSP430 has built in ADC but for ECG data,
instrumentation ADC (ADS1298) is
preferred.ADS1298 is operated at maximum of 3.2v
for digital data, it is an 8 channel low power, 24 bit
resolution delta sigma analog to digital converter, it
uses simultaneous sampling , it has onboard oscillator.
It has all the features required for biomedical
application like ECG recording. Digital ECG data is
sent through SPI bus to ARM7 MCU for
preprocessing.
ARM7 TDMI family of ultra low power
microcontroller consists of several devices featuring
different set of peripherals. The special feature of this
microcontroller that we are going to use are Op-amp,
built in LCD display, ADC, USB interface and
USART.
Sampling of ECG data has to be done , The amplified
ECG signal is given to the instrumentation ADC
(ADS1298) which output’s 24 bits of data per channel
in binary two complement format.A positive full scale
input produces an output code of 7FFFFFh and the
negative input produces an output code of 800000h.
LSB has a weight of Vref/(2^23 -1). The device has
only 17 and 19 bit resolution. The table 1 gives ideal
output code verses input signal [5]. The ADC in the
device offer data rates from 250SPS to 32kSPS.
Communication to the devise is by SPI interface.
Internal oscillator generates a 2.048MHz clock.
Electrode 2
Electrode 1
Electrode 3
ECG Electrode sensor
LM275
Body temperature Sensor
Microcontroller Unit
ADC
INA13
ECG
Acquisition
Unit
Server
system
Doctor
System
Patient
system
Web Unit
Web server network for ECG Recording and Body Temperature Monitoring System based on ARM Microcontroller
International Conference on Electrical Electronics and Communications-ICEEC-21st June 2014-ISBN-978-93-81693-66-03
89
Table 1: Ideal output code verses input signal
The sampled ECG signal contains some amount of
line frequency noise. This noise can be removed by
low pass filtering the signal. The filtered signal can be
output on display unit by the DAC of Microcontroller
unit (ARM) or it can be monitored on LCD display or
transmitted to PC using UART of ARM MCU. Here
we are monitoring the ECG signal on LCD Display
and also transmitted to PC using UART (USB Cable).
The ECG data is processed into server PC using USB
interface and stored in specific format and this format
is converted into web format using html code and the
ECG graph for three electrode and body temperature
data in Fahrenheit is displayed and this recorded data
can be viewed anywhere with secured username and
password by doctor and also by patient.
III. IMPLEMENTATION
A. Hardware Implementation
In our project we using three ECG lead electrodes for
ECG recorder and TMP36/LM35for body
temperature monitoring as shown in figure 4[7][2].
Figure 4: TMP36 and ECG Electrodes
The complete hardware schematic before digital
processing is as shown in the figure 5 below.
Figure 5 :Processing Hardware schematic
The ECG data and temperature data are first
amplified by an instrumentation amplifier and given
as input to the Instrumentation ADC (ADS1298) for
conversion to digital format and it is display on LCD
Display.The figure 6 gives the hardware schematic
for LCD Display module.
Figure 6 :LCD module Hardware Schematic
In this hardware implementation shown in figure 7 ,
The Amplified ECG electrode data from three
electrodes are separated and individually
preprocessed before driving this data into
Microcontroller unit (ARM 7).
Figure 7: Hardware schematic for USB Interface
Web server network for ECG Recording and Body Temperature Monitoring System based on ARM Microcontroller
International Conference on Electrical Electronics and Communications-ICEEC-21st June 2014-ISBN-978-93-81693-66-03
90
The individual Digital ECG Signal are driven into
Microcontroller unit using Serial port interface
(USB).The ECG data which are loaded are converted
to specific format by Microcontroller unit (LPC2148
ARM7 TDMI) and displayedonon- board LCD
Display.
Figure 8: Temperature sensor Hardware Schematic
The Figure 8 shows temperature sensor interface
before ADC conversion. From the figure,
LM35/TMP36 IC are used to read body temperature
to a certain level and this temperature data also need
to be converted to digital to display /store in Server
PC.
The Processed ECG data is recorded to the system
using UART interface from ARM 7 microcontroller
and the data are recorded into web server and also
body temperature are monitored continuously and it
is displayed on on-board LCD display of ARM7
microcontroller and the same temperature data are
displayed in web server.
Few of hardware related challenges was while
designing ADC, Crystal and few register were
interchanged. There was no proper ECG data
recorded. We also faced problem to interface MCU
with PC using USB port. Data to get on terminal
window was really challenging part in this project.
Figure 9: Finished MCU Unit
The figure 9 shows the completely finished MCU
unit withLCD Display .
B. Software Implementation
In our project Embedded C code for ARM
Microcontroller is implemented , mainly the software
code is used for getting digital data in specific format
from instrumentation ADC and this data are displayed
on LCD Display as well as using this code formatted
data is loaded into server system for further
processing
Software implementation involves two flow diagram
or flow chart one is to process ECG data in specific
format from ADC in ARM MCU ,second is to
monitor body temperature data and ECG data in
specific format on LCD display.
The Flowchart diagram for Recording ECG by MCU
into server PC is as shown in Figure 11.
Figure 11: Flowchart for recording ECG Data
The amplified ECG data has to be converted to
digital format so first ADC I/O is initialized .Check
for ADC data, if ECG data available, select 3
channels out of 8 channel and convert to specific
format;send the ECG data into PC using USB. Repeat
the process till reset is made low.
Web server network for ECG Recording and Body Temperature Monitoring System based on ARM Microcontroller
International Conference on Electrical Electronics and Communications-ICEEC-21st June 2014-ISBN-978-93-81693-66-03
91
The Flowchart diagram for ECG and Body
temperature monitoring is as shown in figure 12.
Analog Temperature data is converted to digital data
using ADC. One channel out of 8 channels is used for
temperature monitoring and converted to specific
format. The body temperature is sent to PC using
USB. Temperature reading is displayed in
Fahrenheit.
Figure 12: Flowchart for monitoring Body temperature
IV. RESULTS
A: Hardware result
The figure 13 showcomplete hardware to process the
ECG data on to web server and continuously
monitored on LCD display
Figure 13:Hardware Product
B: Software Result
After Processing of data into specified format by
MCU, simulated results from Eclipse for ECG data
are given in the figure 14.
Figure 14: Eclipse Database Acquired ECG result
C: Web result
The simulated data from CCS studio is converted to
HTML data for plotting ECG graph on Web server.
Temperature data are continuously monitored in web
server. Figure 15 gives login page where we enter
unique username and password. Figure 16 shows
ECG graph on web server which runs in real time
Figure 15: Web server login page
Figure 16: Real ECGgraphin web server
D: Field Trials
Field trial was conducted and compared with existing
ECG device with ECG graph which is recorded in the
Web server network for ECG Recording and Body Temperature Monitoring System based on ARM Microcontroller
International Conference on Electrical Electronics and Communications-ICEEC-21st June 2014-ISBN-978-93-81693-66-03
92
web server for three electrodes, Figure 19 shows the
ECG setup and ECG graph of an Existing system.
Figure 19: ECG setup andGraph of an Existing system
ECG graph for proposed system taken for three electrodes are
shown in figure 20.
Figure 20:ECG Graph for Proposed system
CONCLUSIONS
Our project web server network for ECG recording
and body temperature monitoring system for people
suffering from cardiac disorder who wish to lead an
active lifestyle. In this report ECG recording into SD
card and into web server network is present. It also
present monitoring of body temperature. We have got
successful recording of ECG data and body
temperature is precisely measured.
Only few trial test are done on few people. Actual
test on patient is not explored. This project has wide
scope in small scale industry because of its low cost,
easy access by many people at the same time.
We have considered three electrode in our design,
five electrode design will be explored in future
implementation. Real time access is available only at
the server system where hardware connected.
We will expand our web design for accessing real
time ECG data by doctor system who is at far
distance.
ACKNOWLEDGMENTS
We like to thank our management for giving
opportunity to participate in TI design contest, We
like to thank HOD ,TCEDept BNMIT for her
constant support in completing this project. We like
to thank Dr.Ravish.
H for giving input on medical application and other
medical related information and also for providing
lab facilities to test over project. We like to thank
Santosh .B.S for his support in building web part of
project.
Our sincere thanks to external mentor Naveen. H for
his constant support in making documentation and
building this project.
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