The design of a practical and reliable fall detector for community and institutional telecare

Falls are one of the greatest obstacles to independent living for frail and elderly people. Their early detection is an important step in providing pe ople with the reassurance and confidence necessary to maintain an active li festyle. We have investigated a worn fall detector linked to a community al arm system. A worn device is the only one which is satisfactory, provided t hat it generates few false alarms. The fall detector we have developed is t he size of a small radio pager. It uses a two-stage detection process which senses shock and the orientation of the wearer. A fall is detected within 20 s and triggers a radio signal to a community alarm system. Tests were de vised using a jointed mannequin to simulate five modes of falling to unders tand the effects of impact at different parts of the body. This allowed us to select the appropriate trigger threshold and wearing positions for the s ensor. Prototypes were evaluated with 20 people to observe false alarms. Th e final design allowed reliable detection in 180 different falling scenario s.