THE "CREEPING WAVE" may sound like something from a science-fiction film but it is actually something that researchers in Queen's University Belfast are harnessing to improve medical sensors, writes Áine Bird
"We have been working on a new approach to wearable antennas," says Dr William Scanlon, senior lecturer in the Institute of Electronics, Communications and Information Technology (Ecit) at Queen's, who is the lead researcher on this project. His group is seeking to improve devices that can monitor a person's medical status remotely.
While the wireless sensors are readily available, the challenge is to simplify the antennas needed to get the signal away.
Dr Scanlon is making headway in developing just such a system. "There are sensors placed over the body and a communications network of wireless devices is used to connect them," he says.
The antennas being developed will remove the need to link the sensors using cables. There are a number of problems associated with the use of cables including discomfort, restricted movement and maintenance on the cables, Dr Scanlon says.
"With the type of antennas that are currently available, if you reduce the size of the antenna they can become very inefficient. They could also be sending the signal to the wrong place as they radiate a lot of the energy away from the body and this provides a poor signal link."
The new antennas accentuate the "creeping wave" effect, where the signal "creeps" around the body, following its surface rather than being transmitted outwards or inwards where it is absorbed by the body and thus weakens the signal. This leads to much more efficient antennas. These can be greatly reduced in size and included in clothing or as part of a wound dressing.
"The antennas have also got to be able to work in any orientation. The sensors might be measuring temperature or heart rate and the receiver could be in a backpack or even a shoe," says Dr Scanlon.
"One of our antennas is at the first stage of the patenting application process. The application of the antennas will be driven by the medical devices. The companies developing the sensor devices will then be able to purchase the antenna licence."
The antennas could potentially play a role in the emerging "wireless body area network" (Wban) technology, where a network of biosensors are attached to the patient's body.
"There are a few start-up companies involved in telemedicine," he says.
The thinking behind this is that people spend a shorter time in hospital, where they remain at risk of exposure to MRSA and other infections encountered in hospital.
"Patients recover quicker at home, are up and about and participating in life," says Dr Scanlon. In future doctors may be able to use these systems to monitor patients remotely.
Information on Ecit at www.ecit.qub.ac.uk