Download An Embedded Wireless Module for Telemonitoring

1st International Conference on Advancements of Medicine and Health Care through Technology, MediTech2007,
27-29th September, 2007, Cluj-Napoca, ROMANIA
An Embedded Wireless Module for Telemonitoring
Cristian Rotariu, Hariton N. Costin, Sorin Puscoci, Gladiola Andruseac and Ciprian C.
Costin
Abstract — The current common goal in medical information technology today is the design and implementation of telemedicine
solutions, which provide to patients services that enhance their quality of life. In order to build an embedded wireless module for
monitoring vital parameters in practice, several elements have been used: intelligent sensors used in mobile applications, wireless
communication networks, local intelligence in the form of embedded systems and connections to Internet. In this paper we present
the realization of an embedded wireless module for telemonitoring, as a part of a telemedicine system, capable to acquire and
transmit vital parameters such us blood pressure, heart rate, respiratory rhythm, pulse oximetry SpO2, body temperature and one
ECG lead from a patient. Our wireless module is based on biosignal sensor and an embedded system, which acquires the vital
parameters from the patient and wireless transmits them to the module via the radio interface. The embedded system receives the
data from the sensor, realizes the calculus, activates the alarms and sends the results to a telemedicine centre via the Internet or
GSM connection.
Keywords: telemedicine, telemonitoring, data communications, home care
Doctors can receive information that has a longer time
span than a patient's normal stay in a hospital and this
information has great long-term effects on home health
care, including reduced expenses for health care.
Physicians also have more accessibility to experts,
allowing the physician to obtain information on diseases
and provide the best health care available. Moreover,
patients can thus save time, money and comfort.
1. INTRODUCTION
In spite of decreased mortality, coronary artery disease
still remains the leading cause of death almost all over the
world. The existence of silent myocardial ischemia
emphasizes the need for monitoring of the asymptotic
patient. Extended patient monitoring during normal
activity has become increasingly important as a standard
preventive cardiological procedure for detection of
cardiac arrhythmias, transient ischemic episodes and
silent myocardial ischemia. Existing holter devices
mostly record "24 hour activity" and then perform offline record analysis.
As for patient monitoring, we propose the development of
a flexible embedded wireless module capable of
acquisition, processing and transmission medical data to
a telemedicine centre through Internet, or GSM (mobile
telephony) existing in each Romanian county.
The task may also be achieved by telemedicine (enabling
medical information-exchange as the support to distantdecision-making)
and
telemonitoring
(enabling
simultaneous distant-monitoring of a patient and his vital
functions), both having many advantages over traditional
practice. A telemonitoring network (Figure 1) devoted to
medical teleservices, will enable the implementation of
complex medical teleservices for a broader range of
patients and medical professionals, mainly for family
doctors and those people living in rural or isolated
regions [1].
2. MATERIALS AND METHODS
Our telemedicine interface (Figure 2) is based on
biosignal sensor [2] and an embedded wireless module,
for vital parameters processing and transmission through
Internet/GSM. The embedded module is built by using
custom developed hardware and application software.
The sensor acquires the vital parameters from the patient
and transmits them wireless to the embedded module via
the radio interface.
The parameters acquired by the sensor are: heart rate, 1
lead ECG, blood pressure, heart rhythm regularity,
respiratory rate, oxygen saturation (SpO2) and body
temperature. The sensor has the capability to record, store
and wirelessly transmits data up to 200 meters.
The embedded module is built around a standard
microcontroller connected to the radio interface through a
standard USB connection.
C. Rotariu is with the “Gr.T. Popa” University of Medicine and
Pharmacy, Faculty of Medical Bioengineering, Iasi, Romania,
phone/fax: +40-232-213.573; e-mail: [email protected]
H. N. Costin is with the “Gr.T. Popa” University of Medicine and
Pharmacy, Faculty of Medical Bioengineering, Iasi, Romania, e-mail:
[email protected]
S. Puscoci is with the National Communications Research Institute,
Bucharest, Romania, phone: +40-213-000011, fax: +40-213-189575; email: [email protected]
G. Andruseac is with the “Gr.T. Popa” University of Medicine and
Pharmacy, Faculty of Medical Bioengineering, Iasi, Romania; e-mail:
[email protected]
C. C. Costin is with the ”Al. I. Cuza” University, Faculty of
Informatics, Iasi, Romania, phone: +40-232-201.551; fax: +40-232213.573; e-mail: [email protected]
The heart of the telemedicine interface is an 8–bit
microcontroller (μPSD3234A from ST Microelectronics)
[3]. It has an 8032compatible core capable of being
clocked up to 40 MHz. The μPSD has a memory structure
that includes two independent Flash memory arrays, main
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1st International Conference on Advancements of Medicine and Health Care through Technology, MediTech2007,
27-29th September, 2007, Cluj-Napoca, ROMANIA
Figure 1. Medical network – general structure
Radio
Interface
Wireless Medical Device
USB
Ethernet
Interface
Data Memory
GSM Modem
CPU
A/D
Interface
Microphone
D/A
Interface
Speaker
INTERNET
GSM
Keyboard
Interface
LCD Interface
LCD Display
Keyboard
Figure 2. Block Diagram of the Telemedicine Module
(256 Kb for storing patient data) and secondary (32 Kb
for code), capable of read-while-write operation. It also
contains a large amount of SRAM memory (8 Kb) on
chip, with battery back-up option for RTOS and
communication buffers. The other features of the μPSD
include: communication interfaces such as USB v1.1
Low Speed (1.5Mbit/s), I2C Master/Slave controller
running up to 833 kHz, SPI Master controller, two
UARTs with independent baud rate, IrDA Potocol up to
115 kbaud, 4- channel 8-bit A/D Converter and 5 PWM
channels.
demodulator for the physical interface, Ethernet protocol
controller, memory interface, and many other functions.
The embedded system offers the possibility to make an
audio connection with the patient by using the
microphone and the speaker connected to μPSD through
an external A/D and D/A converters.
The data collected from the sensor, in form of parameters
can be displayed by using a popular alphanumeric LCD
module (LM16x212), having a 16-character 2-line dotmatrix, before sending them to a Telemedical Centre by
using the Internet/GSM connection.
The network controller used is RTL8019AS[4], one of
the modern implementations of the NE2000 standard. It
integrates 16 kBytes of SRAM, modulator and
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1st International Conference on Advancements of Medicine and Health Care through Technology, MediTech2007,
27-29th September, 2007, Cluj-Napoca, ROMANIA
Figure 3. Software working on the expert’s computer
The client server architecture is defined as follows: the
client application provided visualization and contact
facilities to the remote user (i.e., the patient) and provides
control of the telemedicine module. The server takes care
of the incoming data, and organizes patient sessions.
Execution of the client’s application generates the GUI
shown in Figure 3.
The embedded module receives the data from the sensor,
realizes the calculus, activates the alarms and sends the
results to the telemedicine centre via the Internet/GSM
connection. The Internet connectivity of the monitoring
module is implemented by using a standard Ethernet
controller directly interfaced to the module.
In making a decision of the processing platform to use,
several factors were taken into consideration. These are
cost, networking support, and performance. To take
advantage of existing Internet infrastructure (to reduce
cost), it was decided that TCP/IP (Transmission Control
Protocol/Internet Protocol) networking would be used.
Two options existed for Data Link Layer communications
- Ethernet or Phone based Modem. It was decided that
Ethernet would be used, as many existed modules contain
Ethernet controllers and it provides a compact solution.
The increasing prevalence of broadband connections
means that Ethernet connections are becoming more
common in households.
The client’s application is mainly to display the measured
patient’s vital parameters acquired by the sensor.
While the server is running, the client (medical expert)
can start a session from anywhere in the Internet by
accessing the server’s connection port and providing a
proper log in and password.
4. CONCLUSIONS
The wireless module focuses on the implementation and
exploitation of a modular and ambulatory telemedicine
platform, which is using easily wearable vital signs
monitoring devices, causing minimal discomfort to
patients, and which transfer in real time and on-line
critical vital parameters to doctors and/or medical
experts/consultants, regardless of their location, while
getting feedback to increase their comfort in case of
alarm. The interactive continuous monitoring promises
cost effective health services, more active involvement of
patients in their own care, and a new sense of realism in
making a diagnosis.
To make a simple software implementation, we choose to
use the standard TCP/IP network protocol as the link
provider, a scalable and economically feasible tool.
3. RESULTS AND DISCUSSION
The whole telemonitoring system acts as a client – server
application. The server module includes: a database
server for server procedures, tables, restrictions coming
from “client” application; an administration/control
module that supervises general dataflow; an
access/security module; a parameters configuration
module a.s.o. Also, it uses HTML and HTTP to send
most up to date information on heart care to clients.
The proposed system could be used as a warning system
for monitoring during normal activity or physical
exercise. In addition to monitoring of physiological
signals, we plan to use the proposed environment for
development of a high performance user interface. New
user inputs, including correlates of the user's
physiological and emotional states could significantly
improve human-computer interface and interaction.
The client module comprises the software working on the
expert's computer (Figure 3). It has the following
facilities: GUI (Graphic User Interface) for ECG
waveforms; displays the patient’s parameters received
from the sensor; communicates the experts' commands
and medical decisions to the physician/patient.
So, by using the existing Internet-based and embedded
technologies, the quality of medical decision in telehealthcare and emergency medical services systems can
be significantly improved.
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1st International Conference on Advancements of Medicine and Health Care through Technology, MediTech2007,
27-29th September, 2007, Cluj-Napoca, ROMANIA
Enformatika, Transactions on Engineering Computing and
Technology, Volume 17, (2006), 113-118.
[2] www.telcomed.ie, WristClinic™, The all-in-one wireless
remote medical monitoring device
[3] http://mcu.st.com/mcu, “μPSD3234A datasheet”
[4] www.realtek.com.tw/RTL8019AS datasheet
5. ACKNOWLEDGMENTS
This work is supported by a grant from the Ministry of
Education and Research, within CEEX programmes
(www.mct–excelenta.ro),
contract
No.
604/645/
21.10.2005.
6. REFERENCES
[1] Costin H., Puscoci S., Rotariu Cr., Dionisie B., Cimpoesu
M., A Multimedia Telemonitoring Network for Healthcare,
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