The system has already been trialled on 23 elderly people with an average age of 85. It helped them remain independent for twice as long as those living in other settings.

Those monitored by the technology stayed in their own home for an average of 4.3 years, compared to 1.8 years for those who did not have it.

Elsewhere scientists have begun a project to fit thousands of digital sensors to elderly people in the hope it could help detect the very first signs of Alzheimer’s disease.

The high-tech wristbands which have been given 2,200 older people in Boston, in the US, measure everything from sleep, to balance and fall risk, to heart rate.

Scientists hope the three-year project will reveal subtle physical changes that develop during the first stages of the disease and provide an alternative test for picking up the illness.

Currently it is difficult to diagnose Alzheimer’s and requires a number of tests.

Speaking at the American Association for the Advancement of Science (AAAS) annual meeting in Boston, lead author Rhoda Au said the devices could make the process more simple.

"It's really labour-intensive to bring people into the lab for conventional dementia tests,” she said.

Although there are currently no treatments for Alzheimer’s disease, it is hoped that within the next decade, drugs to help stave off dementia will be available. And it is likely that they will work better if the disease is caught in its earliest stages.