Wireless Body Sensor Networks

From Capsil Wiki

Introduction

This chapter outlines the Wireless Body Sensor Networks (WBSNs) component of the CAPSIL roadmap. The current state of the art in terms of technology, applications and research challenges and in particular body worn sensor networks for home monitoring of healthcare and ageing-in place applications are described.

Body Sensor Networks are a specific category of wireless sensor networks intended to operate in a pervasive manner for on-body applications. Much of the theory relating to general wireless sensors relates also to Body Sensor Networks (BNSs) and issues such as power optimisation, battery life performance and radio design are key. These issues are examined in the first section of the chapter and key design considerations such as the correlation between Moore’s Law (i.e. integration density) and power/battery performance are discussed.

Key to body worn sensors are issues such as usability, durability, robustness, how well the sensor ‘fits’ in with the application and reliability and security of the data. Sensor networks suffer from the so called ‘reliability dilemma’ which means that the more reliable and secure you want to make data transmission, the higher the data overhead and consequently the higher the power required, hence battery life is reduced. These issues are discussed and some of the techniques for overcoming this dilemma are discussed. System-On-Chip developments promise to significantly advance sensor integration (and reduce cost) and some of the current offerings in this area are presented. Notable research projects in this space are summarised and current research within the EU is also summarised. This document also examines the software aspects of wireless sensor networks and presents a brief history of operating systems development from the original single thread, event-driven TinyOS to some of today’s multithread systems such as Contiki and Mantis. As sensor networks have evolved from the domain of the programmer and scientist to general use, so have the means of developing solutions and rapid prototypes. No longer do users need to be proficient programmers and developers and environments such as Moteview, LabVIEW and BioMOBIUS™ are presented as environments that facilitate non-programming users to build solutions and rapid prototypes.

Barriers to the general adoption of Body Sensor Networks are then discussed. These issues are mirrors of barriers to telehealthcare and telemedicine in general, and include lack of standards, interoperability issues, privacy and security concerns, lack of large-scale pilot evidence and broadband proliferation issues. These are presented with suggestions of how government influence may help to remove these barriers.

The document finishes with a review of pilot activity and trials that have been carried out both in the domain of telemonitoring i.e. medical monitoring from the home and also Ambient Assisted Living.