Waving or drowning?

. According to Rospa – the Royal Society for the Prevention of Accidents – more than 400 people die in accidental drownings in the UK each year, mostly in rivers, lakes, streams and canals. Another 60 UK nationals drown abroad. Everybody living in the UK should therefore learn to swim. While this cannot prevent all drowning accidents, it would reduce them. Falling into water should lead to a reflex action of swimming to safety, or at least staying afloat until rescued. Learning to swim means going to the local pool. Lifeguards are nowadays always in attendance, but it is still possible for somebody in a crowded pool – particularly a child – to go to the bottom before anybody notices. In many walks of life and work, it is necessary to tell whether somebody is pursuing their normal activities or getting into serious difficulties – be they a child, somebody young and fit, or the elderly. The Challenge Our challenge this month is to come up with a low cost system for raising the alarm when somebody gets into serious trouble – focusing on the problem of monitoring learner swimmers, but possibly extending the technology into other areas. More than a few mariners report that when they were lost at sea, they found themselves being supported by dolphins. Unfortunately, it is not always possible to rely on these creatures – and if kept in captivity they require much looking after and a lot of fish. All sorts of schemes have been conceived that monitor human activity, usually by analysing video images, in order to detect unusual behaviour. Many of these efforts have been devoted to detecting persons intent on either crime or acts of terrorism. The fact that both crime and terrorism both still occur in nations such as ours, which has more than a million CCTV systems, would tend to indicate that such an approach does not work. Even if you are looking at somebody thrashing about in a swimming pool, it is hard to tell whether they are in trouble or not. What is needed is something simpler, and cheaper, that does not depend on supercomputers to crunch data. The solution offered below solves the problem elegantly and at low cost. It has reached the stage of being evaluated in the form of working prototype systems and seems to work well in its target application area. Others, addressing other target markets seem to have come up with remarkably similar approaches. If you know of a better solution, please let us know. For those without access to the web, the solution will be described fully in our March edition. SOLUTION The solution to this month’s challenge was invented and developed by former lifeguard and electronics engineer Jonathan Hawkins, who lives in Hampshire. His system is called Hawkeye and his company set up to exploit it is Pool Safety Systems. Its basis is a micro controller in a unit worn as a head band, which transmits a radio frequency signal to a base station. When we met him, he told us: “Most of the intelligence is in the unit”. He declined to give full details for commercial reasons but did tell us: “It detects when a swimmer has gone into a standing upwards position in the water and is thrashing about.” The development received an R&D grant in October 2005 to fund the development of a working prototype. The company is currently working with leisure companies to develop it into a commercial product. Previously, design consultancy PDD has worked on a similar idea to be worn by the elderly in sheltered accommodation that would detect that the wearer had fallen over. A similar concept alarm device to detect when head of a lorry driver had tilted downward as a result of falling asleep at the wheel has also been proposed. More information at Pool Safety Systems