Design of a Communication System Based on IEEE ... - IRNet Explore

<strong>Design</strong> <strong>of</strong> a <strong>Communication</strong> 

<strong>System</strong> <strong>Based</strong> on 

IEEE 804.15.4 

for Telemedical Applications 

G C Madhu, T.Reshma, N. Suvarna, K.Nomitha Raj & Y. .I.Swetha 

Sree Vidyanikethan Engineering College, Department <strong>of</strong> Electronics and 

Control Engineering 

E-mail : msnaidu417@gmail.com, reshma.krc@gmail.com 

Abstract - This paper deals with 

the design and implementationn <strong>of</strong> the prototype 

<strong>of</strong> a Digital communication system that transmits all 

the information from one point 

to another using an Xbee controller. To test this system we have chosen to transmit the values <strong>of</strong> 

Blood Pressure, body Temperature and position 

<strong>of</strong> a patient from 

home place to 

the doctor room. 

Keywords- Sensors, Xbee module, LabVIEW, Digital <strong>Communication</strong>. 

I. INTRODUCTION 

The present technological evolution is leading to 

many new forms <strong>of</strong> revolutionary needs that meet the 

needs <strong>of</strong> patients. In order to improve 

elderly life 

conditions at home and to 

reduce the costs <strong>of</strong> long 

hospitalizations, the medical world is more and more 

interested in 

telemonitoring 

techniques. 

These 

techniques will allow elderly people to stay safely at 

home, to benefit from an automated medical supervision 

and will delay 

their entrancee in nursing homes. Medical 

pr<strong>of</strong>essionals believe that one <strong>of</strong> the best ways to detect 

emerging physical and mental health problems, before it 

becomes critical (particularly for the elderly), is 

analyzing the human behaviour and looking for changes 

in the activities <strong>of</strong> daily living (ADLs). 

Fig. 1 : Block Diagram <strong>of</strong> the <strong>System</strong> 

II. PROTOTYPE 

This 

system consists <strong>of</strong> two Zigbee nodes with 

each 

node can be controlled by an intelligent ZigBee 

Embedded Microcontroller. To build 

this application 8- 

bit Microcontroller is used as the central core <strong>of</strong> the 

project. Here one ZigBee transceivers act as End Device 

can be placed at patient home (or this system attached 

for patient belt), another one ZigBee act as a 

Coordinator can be placed to doctor’s room 

for 

monitoring the heart beat and fall status. 

Here blood pressure sensor, body temperature 

sensor and accelerometer sensor can be connected to the 

Microcontroller. 

Each 

collection 

<strong>of</strong> data’s are 

transferred through the 

Zigbee controller end device sent 

the information in control room (coordinator). Blood 

pressuree sensor measure systolic & diastolic & pulse 

rate can 

be measured using this sensor. Any body 

movements quickly inform the Accelerometer sensor. 

Body temperature sensor is used to measuring 

the 

human body temperature. Then the system realizes the 

real time 

remote supervisory for the patient information. 

The command windoww which is the output windoww used 

here is the LabVIEW. 

2.1 MICROCONTROLLER 

The 

microcontroller used here is 

P89C51RD2BN. It 

contains 

a non-volatile 64KB Flash 

program memory 

that is both parallel programmable and serial In-<strong>System</strong> 

and In-Application Programmable. The device supports 

6-clock/ /12-clock mode selection by programming a 

Flash bit using parallel programming or In-<strong>System</strong> 

Programming. This device is a Single-Chip 8-Bit 

Microcontroller manufactured in an 

advanced CMOS 

process and is a derivative <strong>of</strong> the 80C51 microcontroller 

International Conference on Electrical Engineering and Computer Science (ICEECS-2012), May 12 th , 2012, Trivendum, ISBN Number : 978-93-81693-58-2 

205

<strong>Design</strong> <strong>of</strong> a <strong>Communication</strong> <strong>System</strong> <strong>Based</strong> on IEEE 804.15.4 for Telemedical Applications 

family. The device also has four 8-bit I/O ports, three 

16-bit timer/event counters, a multi-source, and fourpriority-level, 

nested interrupt structure, an enhanced 

UART and on-chip oscillator and timing circuits. The 

added features <strong>of</strong> the P89C51RD2BN make it a 

powerful microcontroller for applications that require 

pulse width modulation, high-speed I/O and up/down 

counting capabilities such as motor control. 

2.2 SENSORS 

Here we used three sensors to find the three 

parameters <strong>of</strong> a patient. A pressure sensor to find the 

blood pressure using a digital blood pressure meter is 

used. The temperature <strong>of</strong> the body is measured using a 

temperature sensor called LM35. For the position and 

movements <strong>of</strong> the body, an accelerometer sensor 

ADXL335 is used. These sensors are interfaced with the 

microcontroller. 

2.2.1 BLOOD PRESSURE SENSOR 

The method used in electronics systems for 

measuring blood pressure is the oscillometric method. 

The pressure sensor is connected directly to the cuff, 

which is inflated or deflated via a motor and valve. 

voltage is linearly proportional to the Celsius 

(Centigrade) temperature. The LM35 thus has an 

advantage over linear temperature sensors calibrated in ° 

Kelvin, as the user is not required to subtract a large 

constant voltage from its output to obtain convenient 

Centigrade scaling. 

Fig. 3: Temperature Sensor LM35 

The LM35 does not require any external calibration 

or trimming to provide typical accuracies <strong>of</strong> ±1⁄4°C at 

room temperature and ±3⁄4°C over a full −55 to +150°C 

temperature range. Low cost is assured by trimming and 

calibration at the wafer level. The LM35’s low output 

impedance, linear output, and precise inherent 

calibration make interfacing to readout or control 

circuitry especially easy. 

2.2.3 ACCERELOMETER SENSOR 

The ADXL335 is a small, thin, low power, 

complete 3-axis accelerometer with Signal conditioned 

voltage outputs. The product measures acceleration with 

a minimum full-scale range <strong>of</strong> ±3 g. It can measure the 

static acceleration <strong>of</strong> gravity in tilt-sensing applications, 

as well as dynamic acceleration resulting from motion, 

shock, or vibration. 

Fig. 2 : Digital Blood Pressure meter 

Digital Blood Pressure Meter uses an integrated 

pressure sensor, analog signal-conditioning circuitry, 

microcontroller hardware/s<strong>of</strong>tware and a liquid crystal 

display. The sensing system reads the cuff pressure (CP) 

and extracts the pulses for analysis and determination <strong>of</strong> 

systolic and diastolic pressure. This design uses a 50 

kPa integrated pressure yielding a pressure range <strong>of</strong> 0 

mm Hg to 300 mm Hg. 

2.2.2 TEMPERATURE SENSOR 

The LM35 series sensors used here are precision 

integrated-circuit temperature sensors, whose output 

Fig.4 : Accelerometer Sensor ADXL335 

The user selects the bandwidth <strong>of</strong> the accelerometer 

using the CX, CY, and CZ capacitors at the XOUT, 

YOUT, and ZOUT pins. Bandwidths can be selected to 

suit the application, with a range <strong>of</strong> 0.5 Hz to 1600 Hz 

for the X and Y axes, and a range <strong>of</strong> 0.5 Hz to 550 Hz 

for the Z axis. 


206


Fig. 5. Transmitter part <strong>of</strong> the overall system 

Fig. 6. A Zigbee Network 

Zigbee is a wireless communications standard that 

provides a short-range cost effective networking 

capability. It has been developed with the emphasis on 

low-cost, battery-powered applications, such as building 

automation, industrial and wireless, personal healthcare 

and advanced tagging. 

Fig. 6. Receiver part <strong>of</strong> the overall system 

2.3 COMMUNICATION 

The data from the patient needs to be transmitted 

from the patient’s room to the doctor’s room. In this 

project wireless communication is used through the 

Xbee module. It consists <strong>of</strong> a transmitter and receiver 

both based on Zigbee Protocol. Zigbee is specifically 

designed to provide a cost-effective, standard-based and 

flexible wireless network, which supports low power 

consumption, reliability, interoperability and security for 

control and monitoring applications with low to 

moderate data rates. 

The Xbee module can transmit low data rate 

through a distance <strong>of</strong> about 50m. The communication 

card is essentially based on the Xbee module, the 

microcontroller and the USB port. It can provide the 

communication between PC-Xbee, the communication 

between PIC-Xbee and the communication between 

PIC-PC. In addition, it allows users to make Analog to 

Digital conversion to one <strong>of</strong> the five analog inputs. The 

presence <strong>of</strong> the microcontroller on the card is mandatory 

as it is considered as the brain <strong>of</strong> the card. Indeed, it 

manages all communication and determines the mode <strong>of</strong> 

communications and run the Analog to Digital 

Conversion. 

III. LABVIEW 

LabVIEW (Laboratory Virtual Instrument 

Engineering Workbench) is a graphical programming 

language that uses icons instead <strong>of</strong> lines <strong>of</strong> text to create 

applications. In contrast to text-based programming 

languages, where instructions determine the order <strong>of</strong> 

program execution, LabVIEW uses dataflow 

programming. VIs or virtual instruments, is LabVIEW 

programs that imitate physical instruments. 

LabVIEW is used to communicate with hardware 

such as data acquisition, vision, and motion control 

devices, and industrial automation on a variety <strong>of</strong> 

platforms including Micros<strong>of</strong>t Windows, various 

versions <strong>of</strong> UNIX, Linux. LabVIEW contains a 

comprehensive set <strong>of</strong> tools for acquiring, analyzing, 

displaying, and storing data. 

Fig. 7. LabVIEW output at the doctor’s screen 


207


IV. EXPERIMENTAL RESULTS 

To test this prototype many experiments have been 

done with many patients to evaluate the quality <strong>of</strong> 

transmission from different distances. Initially when it is 

tested with one patient at a distance less than 10m, all 

the parameters that were measured are accurately 

transmitted through the Xbee module to the receiver 

section without any error. 

Next it was repeated for gradually increasing 

distances. Every time there was an accurate transmission 

<strong>of</strong> the data from the transmitter to the receiver. 

V. CONCLUSION 

In this prototype the biological data from the patient 

to the doctor’s screen is transmitted via a wireless digital 

communication. As this prototype is used for only a 

distance <strong>of</strong> about 50m using the Xbee module, in future 

this can be extended to a more farther distances 

efficiently. 

REFERENCES 

[1] Nadia Ghariani, Mondher Chaoui, Hamadi 

Ghariani, Mongi Lahiani “<strong>Design</strong> Of A Digital 

<strong>Communication</strong> <strong>System</strong> <strong>Based</strong> On a XBee 

Module For Biomedical Applications”, in 8th 

International Multi-Conference on <strong>System</strong>s, 

Signals & Devices. 

[2] S. Borromeo, C. Rodriguez-Sanchez, F. 

Machado, J.A. Hernandez-Tamames, R. de la 

Prieta, “A Reconfigurable, Wearable, Wireless 

ECG <strong>System</strong>”, in 29th Annual International 

Conference <strong>of</strong> the IEEE EMBS, France, August 

23-26, 2007, pp.1659-1662 

[3] C. Ken, L. Xiaoying, “A Zigbee <strong>Based</strong> Mesh 

Network for ECG Monitoring <strong>System</strong>”, in 4th 

International Conference <strong>of</strong> Bioinformatics and 

Biomedical Engineering (iCBBE), 2010, pp. 1-4 

[4] Yu-Cheng, Su Huan, Chen Ching-Lun, Hung 

Shuenn-Yuh Lee, “Wireless ECG detection 

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and bio-processing ZigBee firmware”, in 

Proceedings <strong>of</strong> 2010 IEEE International 

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2010, p 1216 – 1219 

[5] http://www.laboratoiresdelaretine.com/ 

dmla/wpcontent/up loads/AQDMtelemedicine.pdf\ 

[6] http://www.digi.com/products/wireless/zigbeemesh/xbeedigimesh-2-4.jsp#overview 

[7] V. Auteri, C. Lamberti, L. R<strong>of</strong>fia, and T. S. 

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