Low Power Wearable Antenna Systems
Rapid progress in the area of wireless and mobile technologies has resulted in the development of many devices that are capable of being transported in pockets or otherwise worn on the body. For instance, safety glasses with integrated cameras, MP3 players sewn directly into clothing and wearable sensor systems. These devices typically have the facility to communicate wirelessly to off-body networks and as their prevalence increases it will become a requirement for on-body wireless networks to be implemented offering non-physical connections between worn devices on a single user. With the continuing trend towards personal communications and mobile and pervasive computing, there is a need to create antennas suitable for mounting on the person for scenarios where, for instance, (i) medical sensors integrated into fabric may connect centrally to a transceiver mounted in clothing, or (ii) separate wireless devices in pockets or worn on the body may communicate via wireless on-body channels to a central worn access point for communication off-body. To make these Body Area Networks robust and reliable, it is essential that propagation around the human body is understood to ensure communication channels do not become obstructed or fade and also so that transmission powers can be lowered to prevent battery drain and interference to other systems.
In this project 3D body surface scanning and motion capture equipment is used to measure the precise movement of people wearing wireless devices such as medical sensors, mobile computers and pedometers. The data acquired from this measurement will then be used to animate 3D scans of their bodies. These 'avatars', or computer-animated characters, will allow the team to analyse how radio waves ‘creep’ around the body and from this ascertain the implications for power and battery management on wireless devices. The computer animation expertise in EDA has proved to be of significant benefit for this project. We are probably unique in that we have engineers working alongside experienced digital animators. Ultimately the aim of the project is to represent complicated channel transmission on moving bodies using simplified equivalent networks and models that will enable system designers to model body channels easily.
The inspiration for this project stems from the experiences of children in hospital wards. Currently, children undergoing lengthy observations in hospitals may be ‘tethered’ by cables and wires for long periods. The project seeks to develop technology and an understanding of body mounted wireless communication to free patients from their attachment to monitoring machines. By extension, new methods must also now be found to allow ill and ageing people to stay in their own homes, where many of them would prefer to be.
The project is run in collaboration with the University of Sheffield, Great Ormond Street Hospital and W.L. Gore & Associates.