Imagine an elderly man with dementia who lives in a secure ward of a nursing home and spends his days sadly rattling the door in a futile effort to be allowed to go outside.

In a groundbreaking study, this man was allowed to go come and go as he pleased with the aid of a GPS tracking device. He visits a café, sits while watching people go by, and  returns safely to the facility

Such a program is going on in Norway, where researchers recently reported the results of an innovative study of 200 people with dementia using a GPS device that gives them a measure of independence and allows them to be more active.

The program, which began in 2011, now involves 18 municipalities.

People with dementia are carefully selected and are registered with the municipalities.

The GPS device provides a way to enable the patients to get around without getting lost, and to track them if they do get lost.

The study showed that 20-25 percent of those using the GPS devices were able to live longer at home before needing to go into a nursing home.

Researchers caution that candidates for the devices must be carefully chosen because not all dementia sufferers are able to use them safely.