Enabling IoT: Integration of wireless sensor network for healthcare application using Waspmote Noraini Azmi and Latifah Munirah Kamarudin
Citation: AIP Conference Proceedings 1808, 020010 (2017); doi: 10.1063/1.4975243 View online: http://dx.doi.org/10.1063/1.4975243 View Table of Contents: http://aip.scitation.org/toc/apc/1808/1 Published by the American Institute of Physics
Enabling IoT: Integration of Wireless Sensor Network for Healthcare Application using Waspmote Noraini Azmi1, a) and Latifah Munirah Kamarudin2, b) 1
School of Computer and Communication Engineering, Universiti Malaysia Perlis (UNIMAP), 02600 Pauh Putra, Perlis, Malaysia. 2 Center of Excellence for Advanced Sensor Technlogy (CEASTECH), Lot 16-21, Pusat Pengajian Jejawi 2, Jalan Jejawi-Permatang, 02600 Jejawi Arau, Perlis, Malaysia. a)
b)
[email protected] [email protected]
Abstract. The number of patients that require medical assistance is increasing each day while staff-patient ratio is not balanced causing issues such as treatment delay and often leads to patient dissatisfaction. Besides that, healthcare devices are getting complex and challenging for it to be handled and interpreted personally by patient. Lack of staff and challenges in operating the medical devices not only affect patient in hospital but also caused problem to home care patients that require full attention and constant monitoring. This urges for a development of new method or technology. At present, Wireless Sensor Network (WSN) is gaining interest as one of the major components in enabling Internet of Things (IoT) since it offers low cost, low power monitoring besides reducing devices dependency on wires or cable. Although, WSN is initially developed for military application, nowadays, it is being integrated into various applications such as environmental monitoring, smart monitoring and agricultural monitoring. The idea of wireless monitoring with low power consumption motivates researchers to discover the possibility of deploying wireless sensor network for mission critical application such as in healthcare applications. This paper presents the details on the design and development of wireless sensor network using Waspmote from Libelium Inc. for mission critical applications such as healthcare applications.
INTRODUCTION The idea of Internet of Things (IoT) promotes most applications of things including living things to be connected to the Internet or cloud. Apart from that, the advancement in Micro-electromechanical System (MEMS) also promotes the development of sensor nodes that is small in size, and lightweight. Thereby, promote the development of wireless sensor technologies for various applications such as military application, environmental monitoring, smart monitoring, and also for healthcare applications. The idea of IoT that will connect things including living things such as human to the internet has brought the idea of wireless healthcare especially for elder people who need constant monitoring but does not need to be hospitalized. Monitoring can be done at home such that the data will be transmitted wirelessly to guardian and hospital. Hence, in the occurrence of emergency such as heart attack, rapid action can be undertaken. Wireless technologies also help reduce the dependency of the medical machine towards wire or cable. Thereby, increase the mobility of those devices. There are various scenarios in which wireless sensor network is needed such as in monitoring Alzheimer patients, monitoring elder patient at home, patient monitoring at hospital, preliminary health assessment before detailed diagnosis by doctor, monitoring personal health status and also the loved ones. There are a number of parameters that can be monitored to analyze human healthcare however, the following vital sign are mostly used in several number of research[1]–[3] in order to determine human health condition:
11th Asian Conference on Chemical Sensors AIP Conf. Proc. 1808, 020010-1–020010-5; doi: 10.1063/1.4975243 Published by AIP Publishing. 978-0-7354-1476-1/$30.00
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x x x
Body temperature Heart/ pulse rate Blood pressure
This paper is arranged as follows: Section II briefly describe the available healthcare applications and existing projects, Section III provides details on the design of wireless sensor network for healthcare applications. Section IV concludes this research and also provides some suggestion that can be conducted in the future.
OVERVIEW OF HEALTHCARE APPLICATION & SOME REAL LIFE PROJECTS Healthcare is a major part in human life transcending ages, gender and race. The advancement in technologies assist human in the treatment procedure, and developed method or medication to cure diseases. The successful implementation of wireless technologies in communication motivates researcher to develop wireless system especially for medical devices and application which will further help doctors and medical assistant in treating patients. The following describes some latest devices developed for various healthcare applications: CodeBlue, SMART, MobiHealth, UbiMon, HealthGear, eWatch, iHealth, The Vital Jacket and more. At this point, this research mainly used two types of sensors which are body/skin temperature sensor and pulse/ heart rate sensor. In the future, more sensors such as blood pressure, oxygen level sensor, sugar/glucose level sensor and other suitable sensor will be added to the system. The design of wireless sensor network for healthcare applications involves three main parts which is sensors calibration, software development, and wireless communication which will be discussed in the following section.
WSN FOR HEALTHCARE APPLICATIONS The design of wireless sensor network for healthcare applications involved three main parts which is sensor calibration, board programming and wireless communication. This research used two types of sensors which is body/skin temperature sensor and pulse/ heart rate sensor. In the future, more sensors such as blood pressure, oxygen level sensor, sugar/glucose level sensor and other suitable sensor will be added to the system. The following sections explain some information regarding the sensors used in this project.
Skin Temperature Sensor The body/ skin temperature used in this research is YSI 409B thermistor with rugged surface as in FIGURE 1 [4] and FIGURE 2. The measurement of body temperature depends upon the place in the body at which the measurement is made, and the time of day and level of activity of the person. Different parts of the body give different temperatures readings. The commonly accepted range core body temperatures (taken internally) are between 36.12°C to 37.5°C. In healthy adults, body temperature fluctuates about 0.5°C throughout the day, with lower temperatures in the morning and higher temperatures in the late afternoon and evening, as the body’s needs and activities change. Skin body temperature especially at forehead can be measured as representative to core body temperature which is 98.9% in average similar to core body temperature. More skin temperature condition and its respective temperature ranges are given in TABLE 1. It is of great medical importance to measure body temperature. The reason is that a number of diseases are accompanied by characteristic changes in body temperature. Likewise, the course of certain diseases can be monitored by measuring body temperature, and the efficiency of a treatment initiated can be evaluated by the physician.
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FIGURE 1. Body/skin temperature sensor [5]
FIGURE 2. Placement of body/skin temperature sensor
TABLE 1. Skin temperature range Skin Temperature
Range
Hypothermia
37.5–38.3 °C (99.5–100.9 °F)
Hyperpyrexia
>40.0–41.5 °C (104–106.7 °F)
Sensor Calibration The precision of the body/ skin temperature sensor is enough in most applications but its precision can be improved by a calibration process. The 409B skin thermal probe from YSI is a medical class temperature probe with sensitivity up to 0.02°C. This pre-calibrated sensor comes with standard medical specification that makes it very suitable to use in human body temperature monitoring application. The temperature sensor are actually measuring a voltage, and relating that to the operating temperature of the sensor must be. Recalibration need to be done to this sensor by measuring wheatstone bridge resistance to applied into temperature calculation proses since this probe is resistive type. If the errors in the voltage measurements can be avoided, and the relationship between voltage and temperature can be represented more accurately, then better temperature readings can be acquired. Temperature reading also been compared to other medical class thermometer.
Pulse Sensor Pulse sensor used in this project is Pulse Sensor (SEN-11574) as shown in FIGURE 3. This pulse sensor can be power up using either 3V or 5V supply and it consume low power with just 4mA current drawn at 5V so it is also suitable for mobile applications such as for iPhone or Android based mobile. TABLE 2 provides the range for heart beat measured as in beats per minute (bpm) and the respective heart condition.
FIGURE 3. Pulse Sensor
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TABLE 2. Heartbeat range Heart Condition Bradycardia Normal Tachycardia
Range < 60 bpm 60 - 80 bpm (72 optimal) > 100 bmp
WIRELESS SENSOR NETWORK In order to have a successful transmission, the minimum components required are one transmitter and one receiver. The most basic wireless communication is the point-to-point or widely known as Ad-hoc communication. This project uses the IEEE802.15.4 transceiver module (also known as Series 1) as provided in FIGURE 4. This module is attached to a Waspmote Board. Apart from the IEEE802.15.4 module, there are other wireless modules available such as IEEE802.15.4/Zigbee (also known as Series 2), Bluetooth, Wi-Fi, GSM, RFID and GPRS. However, in this study we choose the IEEE802.15.4 module because IEEE802.15.4 only use 1mW of energy to transmit one packet hence enable longer deployment lifetime.
FIGURE 4. IEEE802.15.4 WSN Transceiver
SYSTEM DESIGN The following is the methodology used in this study. FIGURE 5 and FIGURE 6 shows the Waspmote board with sensor in a casing and Graphical User Interface (GUI) using Labview.
1) Sensor Integration
• Identify and calibrate practical voltage and current for both sensors and Waspmote board 2) Integration of RF transceiver
• Attach the IEEE802.15.4 radio to the Waspmote board 3) GUI development
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• GUI development using Labview
FIGURE 5. Waspmote Board with sensors enclosed in a custom made casing
FIGURE 6. Waspmote Board with sensors enclosed in a custom made casing
CONCLUSIONS & FUTURE SUGGESTION In this paper, the design and development of wireless sensor network tailored for healthcare application is proposed. At this stage, a prototype consists of sensors, processing board, and wireless communication has been built. A Graphical User Interface (GUI) has also been developed. Next step will include the integration of additional sensors into the system and building database that best suits this system. Apart from that, performance analysis for this system will be tested under different wireless condition to ensure stability, accuracy and latency of this system.
ACKNOWLEDGMENTS This research is funded by Grants FRGS 9003-00452: Intelligent Channel Selection Algorithm for IEEE802.15.4 WSNs in 2.4 GHz ISM Frequency Spectrum to Mitigate Coexistence and Interference.
REFERENCES [1] [2] [3] [4] [5]
G. S. Uthayakumar, A. Subramanian, and A. G. I. Kisho, “A novel technique to monitor human body vital signs,” Int. J. Biomed. Adv. Res., vol. 05, no. 01, pp. 79–80, 2014. T. Yilmaz, R. Foster, and Y. Hao, “Detecting vital signs with wearable wireless sensors,” Sensors, vol. 10, no. 12, pp. 10837–10862, 2010. “What Are the Most Common Vital Signs ?,” The American Heritage Stedman’s Medical Dictionary, 2002. T. Components, S. T. Services, and T. Information, “YSI Precision Thermistors & Probes Thermistors at YSI.” P. Disk and C. Sensor, “Model 409B Reusable Skin / Surface Probe Model 409B Reusable Skin / Surface Probe,” no. June, pp. 6–8, 2008.
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