Elderly people with dementia could be tagged to make it easier to track their movements, a minister has proposed.
A rise in the number of sufferers is forecast
Science Minister Malcolm Wicks told the BBC the satellite technology could enable them to lead fuller lives and would reassure their families.
He said it would give sufferers, who often experience memory loss, "freedom to roam around their communities".
The charity Help the Aged said the technology could have "potential" in helping care for people with dementia.
'Dignity and independence'
Mr Wicks said the idea could lead to claims of interference in people's lives, and permission would be needed.
"This is about dignity and independence in old age," said Mr Wicks.
Tagging would have to be with the permission of the elderly person, or at least with that of "their family and loved ones", he said.
"By knowing where they are they could have the safety and security that they would wish for themselves and certainly their families would feel more reassured."
Kate Jopling, of Help the Aged said: "Although when we first hear this it smacks of 'Big Brother', we shouldn't dismiss the possibility of some new technologies to help us in providing better care for people with dementia and care that potentially allows them to stay within their communities for much longer while minimising some of the risk.
"It is a real balancing act but for me the crucial issue is, is the care better for the person with dementia or is it just about our convenience?"
She added: "If we could use technology that is sensitive and with the consent of the families but also the individual then there may be some potential here."
Shami Chakrabarti, director of Liberty, warned against such technology replacing genuine care.
She said: "A debate about better care for the elderly is a good thing but technical gimmicks often provide cheap and quick fixes rather than dignified and possibly expensive care."
In January a project was announced in Devon to provide bracelets for elderly people with dementia to help identify them should they get lost.
The bracelet contains a unique ID code and telephone number which links to a 24-hour support service.
Last month experts predicted that more than 1.7 million people in the UK would have dementia by 2051, costing billions of pounds each year.
Currently 700,000 - or one person in every 88 in the UK - has dementia, incurring a yearly cost of £17bn.
One in 20 people over 65 and one in five people over 80 has a form of dementia, for which there is no cure. Symptoms include loss of memory, confusion and problems with speech and understanding.
Around two thirds of those affected have Alzheimer's disease.