Essay: Wireless System for Body Area Network: Software Development

Abstract — Wireless System for Body Area Network: Software Development or Wi-BAN is a promising technology for mintoring different bio-signal parameters of the patient. For this project, the device is used to monitor health signal such as heartbeat and body temperature. Android is the most popular operating system in the smartphone. This wireles body area network combine with an Android based smartphone via Bluetooth module offers a large functionality. This sub-project is focused on the software development of the system that include data collection of the bio-signal from sensor that is develop and happens in microcontroller Arduino and development of an Android application for data display using UI and storage of the output data from Arduino for end user.
Keywords ‘ body area network (BAN); android application; pulse sensor; temperature sensor
I. INTRODUCTION
As the population in the world is increasing day after day, it brings to the need for more healthcare options. As the death rate reduced due to the development of healthcare technologies and facilities the number of senior citizens is increased in the society. These senior citizens are easily vulnerable to chronic diseases. This requires a proper medical care than the rest of the population [1]. Therefore, the monitoring and recording of biological parameters of patients outside the clinical environment is becoming more important in order to take care of senior citizens.
As for today, the networking technologies are developed very fast. The communication or connection between people, services and multimedia have been changed drastically. The wireless communications technologies also have been affected greatly on people’s lifestyle.
IEEE 802 is an international standardization committee, who had develop various wireless technologies such as Wireless Local Area Network (WLAN), Wireless Personal Area Network (WPAN) and etc. different kinds of wireless technologies are to ensure patient compliance. Especially, Body Area Network (BAN) with the combination of these wireless technologies such as Bluetooth and Zigbee that allow the setup of a comprehensive tele medical infrastructure [1].
According to the report of the World Health Organization (WHO), about 17 million people die around the world due to cardiovascular diseases. If proper medical care is provided to the patients at the right time, then their lives can be saved [3]. For this case, the field of tele medicine becomes very useful. Tele medicine is the field of online monitoring and analysis of vital parameters of the patients and in the emergency situation. It helps to provide medical care as early as possible. By this, the life of the patient can be saved.
II. BODY AREA NETWORK
A. BAN Architecture
Body area network is a network that consists of several body sensor units connected to an embedded system. This system performs the signal processing and data analysis. Fundamentally, body area network consists of the BAN architecture and the communication protocol such as Bluetooth or Zigbee.
Figure 1: BAN Architecture
Based on the architecture above, it shows the different sensor nodes performed the primary data processing. This includes the bio-signal processing and conditioning. The Android smartphone application performed the resulting output that can be viewed on the User Interface (UI) designed for end user. Finally, the processed data is stored in the database of the Android smartphone application. The communication between the microcontroller and the Android smartphone is done through the Bluetooth.
B. Bluetooth Module HC-06
The Bluetooth is the standard IEEE 802.15 communication protocol for exchanging data over a short distance from fixed and mobile devices. HC-06 Bluetooth module is used in this version.
Figure 2 : HC-06 Bluetooth Module
(From: en.ardumotive.com)
This module works on the 2.45 GHz frequency band. The baud rate of HC-06 Bluetooth module is 115200. Auto connects and auto paring with the pin code facility are provided by this Bluetooth module. The Bluetooth module is connected to the Arduino Uno board through serial port. Bluetooth operates on a very low power of 3.3 to 5.0 volts. It provides 3 Mbps data rate for distances of 20 meters, which is very good. The Bluetooth module is very simple to use and certified, which provide the complete wireless embedded system solution within a short distances.
III. ELECTRICAL COMPONENTS
A. Arduino Uno Microcontroller
Arduino Uno microcontroller is used for reliable communication with the Android smartphone, as they are power efficient and provides an ideal platform for Tele care services [2]. The Arduino Uno is a microcontroller board based on the ATmega328. It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz ceramic resonator, a USB connection, a power jack, an ICSP header, and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with a AC-to-DC adapter or battery to get started [4].
The Uno differs from all preceding boards in that it does not use the FTDI USB-to-serial driver chip. Instead, it features the Atmega16U2 (Atmega8U2 up to version R2) programmed as a USB-to-serial converter.
The ATmega328 is 8-bit microcontroller based on the enhanced Reduced Instruction Set Computer architecture (RISC). It is low power IC and has 32K bytes of In-System Programmable Flash, 1024 bytes of EEPROM, 2K byte of SRAM.
Figure 3 : Arduino UNO Microcontroller
(From: store.arduino.cc)
B. Pulse Sensor Module
Pulse Sensor is a well-designed heart-rate sensor for Arduino.
Figure 4 : Pulse Sensor Module
(From: research.ijcaonline.org)
The front of the sensor with the Heart logo is the side that makes contact with the skin. On the front side, there is a small round hole which where the LED shines through from the back. There also a little square, ambient light sensor, under the LED which is exactly like the one used in cell phones, tablets and laptops, that is used to adjust the screen brightness in different light conditions. The LED shines light into the fingertip or earlobe, and then the sensor reads the light that bounces back. The back of sensor is where the rest of the parts are mounted. The Pulse Sensor can be connected to Arduino or plugged into a breadboard.
The sensor must be insulated from sweaty or oily fingers. This is because Pulse Sensor is an exposed circuit board, if the solder point is touch, it could short the board or introduce unwanted signal noise.
Pulse sensor connection is as follow: +V (red), Ground (black) and Analog Pin 0 (purple) on the Arduino board. To power the Pulse Sensor with low voltage, for example 3.3V, make sure that in the setup(), there is analogReference(EXTERNAL); line of code.
Figure 5 : Pulse Sensor connection
(From: http://www.instructables.com)
C. Temperature Sensor Using LM35
The LM35 series IC is one of the precision integrated circuit temperature sensors that give the temperature readings in oCelsius. The output voltage of the LM35 series temperature sensor is directly proportional to the centigrade temperature. In order to obtain Centigrade scaling, the user is not required to subtract a constant voltage from the output. Therefore, LM35 has an advantage over the other temperature sensors that give the output in oKelvin.
Figure 6 : LM35 Temperature Sensor
(From: http://www.ntnu.no)
IV. SIGNAL PROCESSING PROGRAMMING
A. Microcontroller Programming
V. ANDROID BASED SMARTPHONE APPLICATION
A. Android Operating System (OS)
Android is the most popular operating system in the smartphone. It is a software stack made for mobile devices which is consists of an operating system, application and middleware. Fundamentally, the Android operating system is based on a Linux kernel, which designed for different touchscreen mobile devices such as smartphone and tablets.
Android is an open source operating system for touchscreen devices. In an Android operating system, many applications can run at a time. User also may switch between the running applications. Android operating system has the several advantages such as, it is simple and powerful, Java-based development kit, Android development tools. Android also has excellent documentation and library, including classes like Bluetooth Health that is useful to develop on many platforms such as Windows, Linux and Mac operating system.
B. Android Application
Android operating system that is very popular in the smartphone. It’s popularity increasing day by day. It has powerful Java based development kit. So the user can develop an Android application according to its requirements. MIT App Inventor is a block-based programming tool that allows everyone to start programming and build fully functional apps for Android devices. It can program more complex apps in significantly less time than with more traditional, text-based languages. Google’s Mark Friedman and MIT Professor Hal Abelson co-led the development of App Inventor while Hal was on sabbatical at Google. Other early Google engineer contributors were Sharon Perl, Liz Looney, and Ellen Spertus. App Inventor runs as a Web service administered by staff at MIT’s Center for Mobile Learning – a collaboration of MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) and the MIT Media Lab [4]. In this project, MIT App Inventor is used to develop Android applications. This application should feature several functions such as, representing data using UI of Android application and storing output data in the application database.
VI. RESULT
Initially, the embedded system will connect to the Android smartphone using Bluetooth communication. Two sensors are connected to the Arduino UNO microcontroller, namely a Pulse sensor and body temperature sensor. This application can be used by multiple user as they have to register and login first before use the application.
Gambar app
As the system starts, all the two sensors collects their respective readings and the sensor reading are shown in the smartphone screen. The initial android application screen is shown in figure ??. As we open the application in Android smartphone, the Bluetooth setting screen opens after the welcoming screen. It consists of Bluetooth selection and button for disconnect the connection. It also consist of ‘Login’ button. That need to be clicked by user after do the Bluetooth selection.
Then, user login screen will appear. This screen consists of two text box that are, ‘Username’ and ‘Password’, and also have ‘Register’ button to open a registration form for those who not register yet. When the register button is click, the form will appear and the user need to fill the form and when finished, they have to click ‘Save’ button and a popup stated that ‘Information have been saved’ will appear. Then automatically will go to the user login screen. After the user enter the username and password, then click the login button, ‘Main Menu’ screen will appear.
VII. CONCLUSION
The main objectives of this project was to design a wireless health monitoring system using Android smartphone and two sensors namely, pulse sensor and body temperature sensor. The system has implemented successfully on Android platform and resulting output was verified. The pulse sensor have shown slight variation due to interference of noise in the signal. While taking the pulse reading, the user need to calm and the sensor must in a steady state and be moved around to get the correct reading. The combination of the Wi-BAN with an Android smartphone offers a large functionality. This research can be further developed to create a custom Wi-BAN system with different sensors to fulfil user requirement. Some suggestion on the improvement are this system can be improve in term of its wireless connection and the reconfiguration on adding other sensors.
4. http://www.arduino.cc/en/Main/ArduinoBoardUno