Wireless Detectors for Dementia

 Researchers hope that radio transmitters can warn of cognitive decline earlier.The RFID transponder shown here weighs 40 grams. It sends information about the walking patterns of residents at an assisted-living center in Florida, which may reveal early signs of dementia.Researchers at the University of South Florida (USF) have developed a wireless network that evaluates walking patterns in an attempt to detect early signs of dementia. 

Currently, doctors ask patients to answer a series of questions to determine whether they may be suffering from Alzheimer's or another form of dementia. But by the time a patient is diagnosed, she may have already begun to experience symptoms such as memory loss. Drugs that are currently available can only slow the progression of related diseases, so the earlier dementia is caught, the better a patient's treatment will be.

Researchers are exploring ways to identify the condition earlier--for example, by detecting biomarkers, conducting new brain scans, or monitoring movements such as walking. The USF researchers have developed an RFID system that allows walking patterns to be monitored in a natural setting.

"We're looking at a device that may help us perform early detection [of dementia] as a way of ensuring that [older] people get the best remaining years they can," says William Kearns, an assistant professor of experimental psychology at USF. In particular, dementia increases the risk of injury caused by a fall. "That's a huge problem for assisted-living facilities," he says.

To test the approach, the USF researchers put RFID tags on the wrists of residents at two assisted-living homes in Florida. These tags transmitted signals that were picked up by receivers placed around each building, revealing the wearer's movements in all three spatial dimensions to within 10 inches of accuracy.

The researchers analyzed participants' movements for telltale signs of cognitive decline: a tendency to wander, veer suddenly, or repeatedly pause. In a study involving 20 residents the researchers found a statistical relationship between those who showed abnormal walking patterns and those whose mental test scores indicated dementia. In the future, the USF team plans to develop software that will automatically detect these warning signs.

Others are exploring RFID technology as a low-cost way to improve elder care. In 2004, Intel launched a project that used passive RFID tags attached to objects to monitor individuals' everyday activities. This approach can warn a caregiver to check, for example, that a patient has taken his medicine that day. Other systems, such as Accutech's ResidentGuard, send an alarm when users wearing an RFID bracelet venture beyond a designated zone, in order to prevent those with dementia from wandering.