International Journal of Engineering Trends and Technology (IJETT) – Volume 21 Number 2 – March 2015
Simulation of Wearable ECG Monitoring Device
using MATLAB and J2ME Wireless Toolkit
Madhur Gabhane#1, Zahir Aalam*2
#, *
Department of Information Technology, Thakur College of Engineering and Technology, University of Mumbai, India
Abstract— Owing to an increase in the rate of cardiovascular
diseases, it is of utmost importance to provide appropriate
healthcare services to the masses in the form of wearable devices
that are wireless and work in a ubiquitous environment. The
simulation of one such wearable device is shown in this paper.
The device continuously monitors, ECG and if there is any
change in the ECG, sends MMS of the changed ECG to patient’s
mobile phone, which is interfaced to the hardware device via a
Bluetooth interface; and in turn, the patient’s mobile phone will
send that ECG image to a mobile phone at the hospital. The
purpose of this paper is to show simulation of this device using
MATLAB and Java 2 Micro Edition (J2ME) Wireless Toolkit
(WTK).
Keywords— Wearable Devices, Simulation, Mobile Phone,
MATLAB, J2ME WTK, ECG.
I. INTRODUCTION
Electrocardiogram (ECG) is a noninvasive tool widely used
for many years to perform basic cardiac monitoring in a
clinical set-up [1]. With advances in technology, the ECG
recording equipment are available in a smaller form factor.
Due to this improvement it is now practically possible to
develop wearable ECG (W-ECG) equipment for cardiac
monitoring in ambulatory conditions. This project uses the
patient’s ECG under normal conditions for initial setup, stores
this as a reference against which comparisons are made with
the real time ECG signals of the patient in a non-clinical setup
and finally, if any abnormality is found; this ECG plot is
stored digitally in the W-ECG equipment and is sent via
wireless transmission to the hospital.
With advancements in technology, it is now possible to
create wearable devices for Healthcare and diagnostics
purposes [2]. Technology can be introduced in the form of
wireless sensors to form a wireless communication network
that would widely help patients and healthcare professionals
by communicating data in a faster way thereby providing
mobility to the patient. One such device is an ECG
(Electrocardiogram) monitoring device [3]. The device
measures changes in the ECG of the patient, calculates the
change in the ECG parameters and change if any, notifies the
wireless mobile devices. The purpose of this paper is to show
simulation of this device, after which it would be rather easy
to construct the device for practical uses.
ISSN: 2231-5381
II. ARCHITECTURE
A. Description
The Block diagram shown in Figure 1 is the overall outline
of the system proposed. The system that is proposed consists
of three major modules, the hardware, the patient’s mobile
phone and mobile phone at the hospital’s end. The
corresponding modules of the actual system and its simulating
environment are:
B. Working
The Hardware continuously keeps on monitoring the ECG
and compares it with existing ECG plots and if the ECG
parameters are not in the range of the specified ECG plots, the
hardware sends MMS of the ECG to the mobile phone of the
patient; and finally this mobile phone will send that MMS
image of the ECG to the mobile phone at the hospital. The
paper shows working of this system in the form of simulation
using MATLAB and J2ME WTK.
TABLE I
SYSTEM MODULE AND ITS’S CORRESPONDING SIMULATION
Module of the System Proposed
Simulation Environment of that
Module in the System
Hardware
MATLAB
Mobile Phone of Patient
J2ME WTK Emulator 1
Mobile Phone at Hospital
J2ME WTK Emulator 2
III. SOFTWARES USED FOR SIMULATION
A. MATLAB
MATLAB [2013b] – a fourth generation programming
language is used for simulating the hardware, creating and
manipulating the ECG signal; comparing ECG signal with
threshold ECG plots.
B. Java 2 Micro Edition Wireless Toolkit (J2ME WTK)
J2ME WTK– version 2.5.2 is used for simulating the
mobile phones.
http://www.ijettjournal.org
Page 72
International Journal of Engineering Trends and Technology (IJETT) – Volume 21 Number 2 – March 2015
Fig. 1 Block Diagram of System Proposed
C. Simulation Approach
The generation of ECG waveform is done using
MATLAB.
The MATLAB code continuously displays the current
ECG plot of the patient. This plot can be modified using
the Graphical User Interfaces (GUI) interface provided.
The creation of GUI”s has been done using GUIDE
(Graphical User Interface Development Environment),
the MATLAB graphical user interface development
environment [4].
Various options have been provided to manipulate the
ECG signal.
These options control the variable values for ECG
parameters, viz. amplitude of P-wave, length of PR
segment, distortion of QRS – complex, etc.
If these options are used, the necessary variables
associated with them are changed. This causes the ECG
plot to refresh under the current conditions.
Thus, after a certain threshold value of parameters is
breached, a Portable Network Group (PNG) image file
is generated.
This file is accessed by J2ME program code for sending
MMS from one emulator to other [5].
IV. RESULTS
Figure 2 shows the generation of ECG signals by the
MATLAB, as it appears on the GUIDE.
ISSN: 2231-5381
Fig. 2 ECG signal under monitoring
The GUI interface provided for manipulating the ECG
signal is as shown in Figure 3; this figure illustrates the
various buttons that can be used to simulate any required
changes in the ECG parameters. Fundamentally, only four
parameters are present. These have been chosen on the basis
of some identified illnesses [6].
The P-wave in the ECG can help determine Atrial
Premature Beat (APB). This can be made out due to
its shapeless appearance or even due changes in
amplitude.
The PR segment precedes the QRS complex, however,
if it is prolonged over 0.2 seconds, the first degree
atrioventricular block can be diagnosed.
The QRS complex helps determine myocardial
infarction (heart attack). The Q and S parameters in the ECG
vary, causing the QRS complex to be distorted. Thus we can
make out that a myocardial infraction has occurred [7].
http://www.ijettjournal.org
Page 73
International Journal of Engineering Trends and Technology (IJETT) – Volume 21 Number 2 – March 2015
Fig. 3 GUI Interface in MATLAB with Buttons for change in ECG
Parameters
Fig. 5 GUI Interface in MATLAB with change in PR-segment duration
Figure 4 shows Emulator 1 sending emulator (resembling
the patient’s mobile device) and Emulator 2 receiving
emulator (resembling the mobile device at hospital).
Figure 5 shows the MATLAB interface with a slight
change in the duration of PR-segment
Fig 4 J2ME WTK Emulators for sending and receiving ECG images
ISSN: 2231-5381
Similar changes can be observed for parameters- P-wave
and QRS complex. After each change in a parameter, the
respective callback function in MATLAB has been
programmed to check the variation level. If this goes beyond a
safe threshold, an image file is generated in the resource
folder of the J2ME application for sending it as a Multimedia
Message. This image file is of the PNG format and is only
2KB in size. This file is accessed by the J2ME program code
for MMS. In J2ME, this file acts as the resource for sending a
Multimedia Message. This sending of Multimedia Message
has been facilitated by means of the SUN JAVA Wireless
Toolkit 2.5.2. The Wireless Toolkit provides development
environment for J2ME applications and also serves as a
testing tool by means of emulating the mobile screen.
Essentially two files are created in the text editor, which
are saved in the Java format. The MIDlet file - MMSMIDlet
uses a non-blocking, event-driven notification mechanism to
receive messages. It opens a server mode connection that can
receive incoming messages. However this server mode
connection can also be used to send messages. The class file MMSSender is used by the MMSMIDlet file to send multipart
messages. Since this file contains a connection created in the
client mode, it can only send messages. Both these files act as
source codes for the mobile device application, and when the
application is run on WTK simulator, these codes enable the
sending and reception of image.
http://www.ijettjournal.org
Page 74
International Journal of Engineering Trends and Technology (IJETT) – Volume 21 Number 2 – March 2015
Fig. 6 Receiving Emulator showing change in PR-segment duration
Fig. 7 Receiving Emulator showing an increase in the P-wave
amplitude
After a change in the values of the PR-segment duration
and P-wave amplitude, modified ECG images are received on
the emulators of J2ME WTK, figure 6 and figure 7,
respectively.
ISSN: 2231-5381
http://www.ijettjournal.org
Page 75
International Journal of Engineering Trends and Technology (IJETT) – Volume 21 Number 2 – March 2015
V. CONCLUSION
Advances in the field of Information and Communication
Technology has made it possible for the construction of small
sized wearable devices which are able to work in a wireless
environment, on their own, without the involvement of the
patient. The simulation results obtained were carried out to
show the working of the proposed system and thus it is now
practically possible to implement such a system for uses in
real time environments. The implementation of the system
proposed is simple and feasible, and can serve a host of
patients suffering from heart related diseases.
REFERENCES
[1]
[2]
[3]
[4]
[5]
[6]
[7]
Subhasis Chaudhuri, Tanmay D. Pawar and Siddhartha Duttagupta,
“Review of ECG Analysis,” in Ambulation analysis in Wearable ECG,
Springer, 2009, pp. 15-21.
Borromeo S, Rodriguez-Sanchez C, Machado F, Hernandez-Tamames
JA and de la Prieta R, “A Reconfigurable, Wearable, Wireless ECG
System,” presented at IEEE Int. Conf. EMBS, Lyon, France, 23rd-26th
Aug. 2007.
Madhur Gabahne and Zahir Aalam, “Design and Modeling of wearable
ECG (Electrocardiogram) monitoring device for Heart Patients,”
unpublished.
Brian R. Hunt, Ronald L. Lipsman and Jonathan Rosenberg, A guide to
MATLAB: for beginners and experienced user, 2nd ed. Cambridge
University Press, 2006.
James Keogh, J2ME: The Complete Reference, Berkeley, California,
McGraw-Hill/Osborne, 2003.
Dr. Aswini Kumar (2014, Nov. 14), ECG in 100 steps [Online].
Available: http://www.lifehugger.com/doc/120/ecg-100-steps
P. E. Trahanias. “An Approach to QRS Complex Detection using
Mathematical Morphology,” IEEE Trans. on Biomed. Eng., vol. 40, no.
2, pp. 201-205, Feb. 1993.
Fig. 8 Receiving Emulator showing a negative P-wave and a
distorted QRS complex
ISSN: 2231-5381
http://www.ijettjournal.org
Page 76