DEVELOPMENT OF WI-FI BASED TELE-CARDIOLOGY MONITORING SYSTEM

ByNIDHIN CHANDRAN

S5 AE,N0:36M.P..T. C MATTAKKARA

CONTENTS INTRODUCTIONSYSTEM ARCHITECTURETHEORY i) Implementation of the system

MATERIALS AND METHODS i) Amplifier and Filters ii) The Main Control Module iii) Introduction of Wi-Fi and Transmission Module iv) Why uClinux? v) Implementation of System SoftwareCONCLUSION AND FUTURE WORKSREFERENCES

INTRODUCTIONECG provides information for the detection, diagnosis, and therapy of cardiac conditions

Remote wireless health monitoring systems are based on using wearable sensor devices

In a traditional ECG monitoring system, a quite bulky and cumbersome instrument with multiple cables and electrodes is used

New wireless technologies and sensors network allow patients the freedom to be mobile and still be under continuously monitoring

The objective of this paper is to develop a system that can be supplemented with real-time wireless monitoring systems which are designed and implemented through IEEE 802.11 (Wi-Fi)

SYSTEM ARCHITECTUREThe system consists of a portable ECG sensor, router,

modem, an ECG console, and a database server as shown in Fig

Design of the monitoring system is twofold and includes both hardware and software development

The hardware system design is based on front-end data acquisition circuits, digital signal processing and storage, wireless transmission, and power management system

Fig. provides a block diagram of the current system structure

THEORYThere are three different phases to operate our proposed

systemThe first phase, patient's end devices will select the shortest

distance in personal operation space and the number of associated device of router to join automatically

Second phase, when device has joined a router, a wireless ECG sensor continuously measures the heart records and transfers them directly to associated router over the WI-FI network

Third phase, when router receives a data from device, it will send data to the ECG console for physicians in the hospital via the

IEEE 802.11 (Wi-Fi)ECG console receive data from the network and store it to

databaseThe physician examines the received data and sends an

immediate feedback directly to the patient, thus continuously monitored

Implementation of the system

Ecg-sensor chip

MATERIALS AND METHODS i. Amplifier and Filters

A preamp component is required to increase this weak signal into an acceptable level for practical purposes.

  

The preamp component consisting of an instrumentation amplifier AD620 is used to detect the signals induced from the leads

0.5Hz high pass filter was designed and implemented to eliminate baseline wandering and low frequency noises embedded in the ECG signal.

A right-leg driver is employed to eliminate power supply noise caused by commercial power sources

Lastly, a signal amplification circuit and a 5th order Butterworth low pass switch capacitors filter with cutoff frequency of 100 Hz were applied for detection of final analog ECG signals

ii)The Main Control Module It consists of an ARM7TDMI-S core based microcontroller

LPC2478 LPC2478 microcontroller has 512 kB of on-chip high-

speed flash memory It incorporates an LCD controller, a 10/100 Ethernet

Media Access Controller (MAC), a USB full-speed Device/Host/OTG Controller with 4 kB of endpoint RAM, four UARTs, two Controller Area Network (CAN) channels, an SPI interface, two Synchronous Serial Ports (SSP), three I2C interfaces, and an I2S interface, ADC etc

All of these features make the LPC2478 particularly suitable for industrial control and medical systems

The main control module is to accomplish the conversion from analog amplification ECG signal collected by acquisition module to A\D signal, encode the signal and enable LCD to display electrocardiogram, send to the WIFI module through UART port

iii) Introduction of Wi-Fi and Transmission Module

Wi-Fi is a wireless local area network (WLAN) devices based on the IEEE 802.11 standards

Wi-Fi works with no physical wired connection between sender and receiver by using radio frequency (RF) technology

Lantronix WiPort is selected as the wireless channel to transmit ECG signals to a host device

Lantronix WiPort integrates: two serial interfaces, Ethernet connectivity, a RISC microcontroller with a TCP/IP protocol stack and a Real Time Operative System

Communication between the microcontroller and the WiPort is made through an UART interface.

Basic components of Wi-Fi and transmission module

LANTRONIX WiPort Router

Hub Modem

iv) Why uClinux?

uClinux is used as an operating system for our ECG monitor

uClinux (Micro-C-Linux) is a Linux derivative intended for microcontrollers without Memory Management Unit(MMU),which is free and open source software under GNU Public License

Its support to a very large number of existing applications, the provisions for easy system configuration and the low cost

The uClinux is much, much smaller than Linux kernel It retains the main advantages of Linux OS: stability,

superior network capability and excellent file system support

uClinux retains the main advantages of Linux OS: stability, superior network capability and excellent file system support

v) Implementation of System Software uClinux is ported on the NXP LPC2478 platform and it supports a lot of kernel functions to handles interrupt, timer, task schedule and resources management of hardware

ECG data acquisition module invokes A/D conversions Driver module to collect data periodically from the electrodes.

After conversing and combining, the normal data are transmitted to transmission module and put into a shared memory

If the checking result is an alarm condition, Alarm task will send an alarm message to user

The structure of software can be seen in Fig.

CONCLUSION AND FUTURE WORKSA portable intelligent electrocardiogram monitoring system using the WI-FI wireless network technology is presented

The system is able to transmit ECG signal to monitoring center in the hospital via wirelessly using a WIFI wireless sensor node

It is capable of continued ambulatory monitoring of health conditions with no restrictions on patient's movement

This proposed system can have great impact on the development of new health care monitoring system for patients and provide better healthcare services

To reduce the power consumption of system, a Zigbee-compatible wireless sensor node will be used for wireless transmission of measured ECG data

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power,wireless two-lead EKG system", 26th Annual International Conference of the IEEE EMBS, September 2004.

E. Jovanov, A. O'Donnel Lords, D. Raskovic, P.G. Cox, R. Adhami,and F. Andrasik., "Stress monitoring using distributed wireless intelligent sensor system", IEEE Engineering in Medicine and Biology Magazine,pp. 49-55, May 2003.

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Hande Alemdar , Cem Ersoy ,” Wireless sensor networks for healthcare: A survey”

B. Priya, S. Rajendran, R. Bala and Gobbi. R, Member, IEEE ” Remote Wireless Health Monitoring System”Paula Corabian ”Accuracy and reliability of using computerized

interpretation ofelectrocardiograms for routine examinations” January 2002 HTA 25: Series A Health Technology Assessment