New wireless monitoring device prevents and detects mobility problems among elderly

Jan 7 2010

Falls are the main cause of injuries among elderly people, but until now doctors have had few ways of effectively monitoring and counteracting mobility problems among patients. Work by European researchers is set to change that.

Mobility problems, ranging from frequent accidental falls to difficulty standing up or walking, affect millions of Europeans both young and old. Elderly people in particular become more liable to trip due to poor eyesight or poor balance, while health complications, such as strokes and circulatory problems, or debilitating diseases like Parkinson's and Alzheimer's can make performing everyday tasks - even reaching into a cupboard - difficult or even dangerous.

Injuries caused by falls among the elderly range from mild scrapes and bruises to serious complications requiring long-term treatment. Nine out of ten hip fractures, for example, occur in people over 50 - and 80 percent of them women.

"Falls and other mobility problems have a major societal and economic impact," says Lorenzo Chiari, a researcher at the University of Bologna, Italy. "For the elderly, there is not only the risk of physical injury but also the psychological trauma falling causes and the long-term effects mobility problems have on quality of life. For healthcare systems, the costs of treating injuries caused by falls are only going to escalate as Europe's population ages."

In Chiari's view, new technology offers a solution. Just as advances in sensing devices and wireless communications are allowing doctors to monitor their patients' vital signs remotely through so-called telecare and telemedicine systems, similar technology can be used to monitor, prevent and detect mobility problems.

Monitoring mobility remotely

The approach, developed by a team of researchers led by Chiari as part of the EU-funded SensAction-AAL project, involves using a wearable, wireless-enabled device equipped with motion sensors to monitor people susceptible to falls. The information can then be used to help patients perform rehabilitation exercises to improve their balance and mobility, evaluate the progression of a disorder or, crucially, alert emergency services, doctors or relatives in the event of a fall.

"Falls in which a person does not get up, so-called unrecovered falls, are usually a sign that they need immediate assistance. But detecting them remotely is not easy. The main challenge is developing a software algorithm that can differentiate between an unrecovered fall and something less serious," Chiari explains.

The SensAction-AAL team's software is able to detect unrecovered falls with a high degree of accuracy and send an SMS or e-mail alert immediately. That makes it a potentially life-saving technology in the event that a user has suffered a heart attack, stroke or other serious health incident.

The software is embedded in the same compact device, designed to be worn around the waist, which also contains the gyroscopes and accelerometers used to carry out the motion and position sensing. Bluetooth or Zigbee wireless communications technology connect it to the user or doctor's computer and, via an internet connection, to a secure database and server.

"We wanted to ensure that the device was comfortable, compact and simple to use. We didn't want to have sensors and wires connected to people's arms, legs and chests as it is not very comfortable or practical for the patient," Chiari says. "Combined with the sense of safety and reassurance that remote monitoring gives patients, I think the design helped us overcome the obstacles that often occur when introducing new technology to older people."

Besides alerting caregivers in the event of an emergency, the SensAction-AAL system also provides doctors with long-term information about patients' mobility, including objectively reporting falls that may otherwise go unreported, masking potentially serious health problems.

"Such information, taken from many patients will help the medical community gain a better understanding of what causes falls and what happens before, during and after a fall, ultimately leading to better preventive care," Chiari says.

In addition, the SensAction-AAL system can assist people undergoing rehabilitation programmes by encouraging them to perform prescribed exercises. Patients' movements, picked up by the accelerometers and gyroscopes, can be translated into feedback signals, such as sounds and vibrations emitted via an audio headset or small vibrating actuators on different parts of the user's body. The patients can learn to improve their balance and posture by responding to changes in pitch, tone and intensity.

"One application involves using the device as an MP3 player so the user can listen to their favourite music while exercising. If they move incorrectly the music will become distorted or change volume or tempo," Chiari says.

Improving quality of life

In trials conducted with sufferers of Parkinson's disease at three different sites in the Netherlands, Germany and Israel, test users were overwhelmingly positive in their evaluation of the system, underscoring particularly how increased monitoring can help their self-confidence and, in turn, improve their quality of life.

The wearable monitoring device developed by the project is currently being commercialised by project partner McRoberts, while other components and software have fed into products being developed or sold by other partners.

Chiari says that the consortium is interested in finding investment partners to help conduct more extensive clinical trials and develop a commercial version of the full system.