On Body System For Continuous Health Monitoring

Published Date: 02 Nov 2017

Abstract: The rapid technological growth in physiological sensors, low power integrated circuits and wireless communication has enabled a new generation of wireless sensor networks. These wireless sensors networks are suitable for different applications i.e. traffic monitoring, plant monitoring in agriculture, infrastructure monitoring and health monitoring. However our work is related to Wireless sensor technology for health monitoring applications called WBAN (Wireless body area network). WBAN is a rich interdisciplinary area that revolutionizes health care system by allowing inexpensive, continuous and ambulatory health monitoring with real time updates of medical record via Internet. A number of intelligent physiological sensors can be integrated into a wearable wireless body area network, which can be used for computer assisted rehabilitation and even early detection of medical conditions. Though there is some limited research going on in this area, but its applications are not practically implemented in hospitals or other health care centers. It is only limited to laboratories. Making WBAN practical for hospitals is a challenging task, which is still not achieved. In this paper, we discuss about the importance of wearable WBAN in healthcare system that could be practically implemented in hospitals.

Keywords: Physiological Sensors, Wireless Body Area Network, Health Monitoring

Introduction

As stated by US Bureau of Census, the Nation's population is forecasted to increase to 70 million by 2025 - more than a 50 percent increase from the year 1990 population. It is a global flow and expected to be double by 2025. On the top of it, another survey shows that one third of US adults, most of them having full time jobs were serving as an informal caregiver- mostly to parents. Moreover in less than 10 years, health care expenditure will reach nearly 20% of a GDP (Gross Domestic Product). Providing a better and affordable health detection system could control all these problems. It’s better to detect a disease earlier rather than treating it later. WBAN technology provides long term monitoring by continuously monitors the patient’s activity and supports us in early detection of abnormal condition and its serious consequences. For example, we will be able to predict heart attack in advance and can treat it accordingly. Traditionally wired

Figure: 1 WBAN System for Continuous Health Monitoringtechnology has been used for monitoring purposes, which could restrict the patient activities and level of comfort. We don’t want the patients to be restricted to bed or hospital and limit their activities. Hence we move forward from wired to wireless technology. The patient’s activities will be monitored continuously (without using unwieldy wires) at their homes, offices and even during playing sports.

Our aim is to develop a flexible and proactive prototype, which could be practically implemented in hospitals. Traditionally holter monitors have been used to gather data for offline processing, which is not suitable for real time applications. A health-monitoring device using PAN (personal area network) has been integrated into user’s clothing [1]. However this type of system limits the patient’s normal activity. A WBAN prototype for computer assisted physical rehabilitation applications has been developed by [2]. The researchers actually focused on general system architecture and described an activity sensor called "ActiS-Activity Sensor" which is based on a standard wireless sensor platform and a custom sensor board with a one-channel bio amplifier and two accelerometers [3]. The ActiS when using ECG (Electrocardiogram) as a bio amplifier will monitor heart activity and position of upper trunk. While by using EEG (Electroencephalography) as a bio amplifier, the same ActiS can be used to monitor brain electrical activity. The ActiS is specifically developed for WBAN. Therefore we will use ActiS as a wireless sensor platform during our research. In order to understand the concept more precisely, please consider the following diagram, which is the best example of a complete Wearable WBAN [2].

Figure 1 indicates three-tier architecture of Wearable WBAN developed at Department of Electrical and Computer Engineering, University of Alabama in Huntsville. The lowest level contains a set of physiological sensors called tier 1. The second level is the personal server i.e. Internet enable PDA or home computer called tier 2. The third level called tier 3 contains a network of remote health care servers. Each level is very complex to implement. This diagram is only given in the paper [2] as very good example of a complete WBAN system. But they actually focused on lowest level i.e. development of hardware for various physiological sensors. Hence the second and third level is still a big issue to deal with.

The scope of a WBAN spans around three domains: Off-body communication, On-body communication and In-body communication. Off-body communication is the communication from the base station to the transceiver on human side. On-body communication is the communication within on-body networks and wearable system. In-body communication is the communication between invasive or implantable devices with a base station. This paper contains a brief overview of WBAN architecture and wearable WBAN on-body communication for the continuous patient health monitoring.

Research Design

Let us first explain the multi tier architecture being given in Figure 1. Different sensors are integrated at different points i.e. ECG for heart monitoring, SpO2 for oxygen saturation and motion sensor on ankle etc. These sensors continuously monitor their corresponding organs and send the data to a personal server (Internet enabled PDA or home computer) using zigbee protocol. The data being received by PDA or home computer is sent to remote health care servers. This enables remote health care servers to continuously update the patient information in databases. GPRS technology assists us in finding the correct location of a patient.

E. Jovanov has partially worked on the lowest level i.e. introducing ActiS as a very good platform for the integration of different bio amplifiers [2]. His work reduces some of the complexity at the lowest level. But the problem of monitoring continuous data and sending it to PDA is a very complex issue. Moreover, at the lowest level, zigbee protocol is used, but from PDA to remote health care system, zigbee is not a valid protocol. Therefore the PDA must have a capability of receiving data using zigbee protocol and sending it to remote health care servers using Internet protocols. Furthermore, the remote health care servers are expected to receive large amount of data. So we also need different data mining techniques that could help us in managing this large amount of data. Theoretically it’s very easy to explain the architecture of WBAN but practically it’s like a hard nut to crack. As a matter of fact we can say that Health care monitoring with WBAN is a real-time service which requires strict and quality demands [4]. The health monitoring with WBAN may become realistic, practical and level-headed, but it embraces numeral research challenges [5].

As WBAN is an interdisciplinary area which requires assistance of Medical and Computer Science experts. Fig 1 shows a sketch of a complete Wearable WBAN. The work should be distributed among three different departments. Medical department could be very helpful in providing technical information about various physiological sensors. Our lab should work on the lowest level i.e. integration of physiological sensors using BSN platform. Moreover our task includes getting continues data from each organ, process it at sensor level BSN, and send it to an Internet enable PDA or mobile using zigbee or UWB. The PDA will forward the received data to health care servers via Internet. The third level requires assistance of computer experts i.e. sending data from PDA or mobile to health care servers via Internet. How to treat this large amount of data is the task of computer experts. They are supposed to develop a database that could receive this large amount of data directly from PDA and could store it accordingly. Likewise data entered into health care servers provide support for data mining and knowledge discovery relevant to specific conditions and patient categories. Hence different data mining techniques are required that could find various patterns (related to patient’s record) in these databases.

For the lowest level we need various types of physiological sensors and a platform for operation of these sensors. Moreover, for the second level we need an Internet enabled PDA or mobile which could receive data from each sensor node and forward it to health care servers. Finally, there is a need of telemedicine server that keeps record of all the patients in databases. The physiological sensors, an Internet enabled PDA or a home computer, and a telemedicine server is required in order to accomplish the wearable WBAN for health monitoring.

Conclusion

This paper presents a brief overview of wearable WBAN which has revolutionized health care system by integration of miniature, low power, non-invasive and inexpensive intelligent sensors to provide an adaptable and ambulatory health monitoring system. Substantial numbers of on going research efforts have enabled the innovation of several prototypes for pervasive healthcare system. We have described the importance of wireless BAN in healthcare applications. We have also presented our own idea of developing a wearable WBAN for ambulatory health monitoring system using various sensor nodes. We are expecting to have a feasible and proactive prototype for Wearable WBAN system, which could improve the quality of life. Typical application includes physical rehabilitation after hip or knee surgeries, stroke rehabilitation, and myocardial infarction rehabilitation etc. Traditionally the computer assisted rehabilitation is only limited to laboratories. We are expecting to bring the Wearable WBAN technology for rehabilitation purposes from our laboratories to real life situations.