Researchers at Chalmers University of Technology in Sweden have developed a method to predict falls and cognitive diseases such as Alzheimer’s by reading a person’s gait using a radar sensor.
The new method uses a small radar sensor to read a person’s gait pattern in real time, at high resolution, especially the time it takes to take a step.
“It is the variation in step times that is key. A healthy person normally has a regular gait pattern. But a person at risk for falls often has a wide variation in step times. For example, the first step might take a second, while the second might take two seconds,” said Xuezhi Zeng, a biomedical electromagnetism researcher.
Without filming
A product with the sensor is no bigger than a fire alarm and could be used in healthcare, at home or in elderly care to identify risks. Preventive measures such as physiotherapy, customized training or adaptation of the home furnishings can be applied to prevent falls.
In addition to ease of use, another advantage of the method is that it collects data without filming. “This means it can be used without intruding on people’s privacy and integrity, and without the sense of surveillance that something like a camera would provide,” says Zeng.
An increase in step time variability is also often an early symptom in cognitive diseases such as Alzheimer’s disease. Alzheimer’s disease is one of the most common causes of dementia in the world and is difficult to detect at an early stage. Here, too, the method can be useful as an aid in making an early diagnosis and contribute to preventive measures and a better quality of life.
The method is based on an off-the-shelf radar sensor and therefore commercial development is possible in the near future. In the short term, Zeng hopes it can be used at home by the elderly and provide healthcare staff with objective and valuable data to support decision-making. She also hopes that the method will facilitate clinical research in the elderly in the future and establish more links between a change in gait pattern and the development of other diseases.
In Sweden each year about 100,000 people aged 65 or older fall so badly that they require medical attention, 70,000 of whom require hospitalization. About 1000 elderly people die every year as a result of a fall accident. In the U.S., an estimated 3 million older adults each year seek emergency care as a result of a fall.