Wireless home network can detect falls by elderly

University of Utah engineers say a home wireless network can detects falls by the elderly without requiring them to wear monitoring devices. The monitoring technology could be linked to a service that would call emergency help in the case of a fall, a leading cause of death for people 65 and older, they said. A 2008 study showed 80 percent of elderly adults who owned wearable call buttons didn't use the device when they had a serious fall, largely because they hadn't worn it at the time of the accident, a university release reported Monday. Utah engineers Brad Mager and Neal Patwari say they've developed a fall-detection system using a two-level array of radio-frequency sensors placed around the perimeter of a room at two heights that correspond to someone standing or lying down. Anyone standing -- or falling -- inside the network alters the path of signals sent between each pair of sensors, they said. "The idea of 'aging-in-place,' in which someone can avoid moving to a nursing home and live in their own home, is growing," Patware said. "Ideally, the environment itself would be able to detect a fall and send an alert to a caregiver. What's remarkable about our system is that a person doesn't need to remember to wear a device." By measuring the signal strength between each link in the network, an image is generated to show the approximate location of a person in the room with a resolution of about six inches, the researchers said. The system is programmed to detect whether a fall was indeed a dangerous one, rather than someone simply lying down on the floor, they said. Experiments measuring the amount of time that elapsed when a person fell, sat down, or laid down on the ground allowed the researchers to determine a time threshold for accurately detecting a fall. "With this detection system, a person's location in a room or building can be pinpointed with high accuracy, eliminating the need to wear a device," Mager said.