Proposed electronic tagging of people with dementia, with their agreement, has been backed by a charity.
The number of dementia sufferers is predicted to soar
The Alzheimer's Society said the plan could empower patients by allowing them to wander, but called for a debate on the ethics of gaining consent.
Many people with dementia feel compelled to walk about outside - the society says 60% may wander, and 40% have got lost at some point.
The government has said tagging could allow people to lead "fuller lives".
Science Minister Malcolm Wicks first proposed the measure in April.
He said people with dementia would gain the freedom to "roam around their communities" without their families suffering the anxiety that such wandering can currently cause.
The chief executive of the Alzheimer's Society, Neil Hunt, agrees that the technology "could offer benefits to people with dementia and their carers".
But he stressed: "There is a careful balance to strike between empowering people and restricting their movement and this technology can certainly never be used as an alternative for high quality dementia care."
Dr Richard Nicholson, editor of the Bulletin of Medical Ethics, said the scheme had potential pitfalls.
He told BBC Radio 5 Live: "The problem with this is that you could see second-class care - using it as a way of making life easier for carers rather than as a way of making life safer or more pleasant for the person with Alzheimer's."
He said the scheme was "not something that ought to go ahead without parliamentary debate and possibly even legislation".
Peace of mind
Kate Ghosh, director of the British Institute of Human Rights, said the use of a tracking system should never be "a substitute for proper resources".
"Some people are rightly questioning this and are wanting to be very sure that it's not going to be something that would just be used for convenience when there could be other measures that could be taken," she said.
Such measures could include those to help "protect people for their own safety but also, perhaps more fundamentally, to enable them to carry on being as free as they possibly can", she added.
Elizabeth McLennan, policy officer for Help the Aged, said electronic tagging was a good idea in principle.
"But it must always be determined by choice - it cannot be the case that a diagnosis automatically goes hand in hand with a tag," she said.
"If older people get confused and wander off it can put them in danger and cause a huge amount of distress and worry for their family. Tagging could potentially allow people with dementia the chance to retain their freedom and help to keep them safe at the same time."
The British Geriatrics Society (BGS), an association for doctors practising geriatric medicine, said tagging could be of benefit to patients, carers and families but warned against rushing into it.
BGS chief executive Alex Mair said: "It is a laudable objective but would have to be extremely carefully worked out in advance as it could be open to abuse."
The Alzheimer's Society said decisions about whether to use a tracking device should be made in conjunction with the person with the disease in the earlier stages of dementia.
Chief executive of the Alzheimer's Research Trust, Rebecca Wood, said she would want health workers to talk to people at an early stage to get informed consent.
Global Positioning System
Marilyn Loveday, who cares for her husband, Christopher - who has Alzheimer's - said she thought tagging could prove invaluable for carers.
She told BBC News: "In the earlier stages, I would have welcomed it because he just used to leave the house and we didn't have a clue where he was and quite often he'd be gone for hours."
Tracking devices use the Global Positioning System (GPS) to locate the wearer.
There is currently a growing market for devices which allow parents to monitor their children's whereabouts, but even here the issue has proved controversial.
There are currently 700,000 people living in the UK with some form of dementia. This is predicted to reach 1.7m by 2051.
I am 78 years of age and enjoy a very full and active life. I am in a position to say that I would welcome the use of a tag on me should it ever be needed. I accept there may be some negative aspects but the plusses outweigh any negatives. Ask us oldies about these issues while we are still in a position to make our own valued judgments. And forget the advice of the "Do Gooders" of this world
Neal Martin, Gladstone, Australia
This is not the right solution in every case, but it must be a relief to some families and their loved ones who get disorientated and into dangerous situations - and it is preferable to committing such unfortunate folk to care homes who are not designed for dementia and force anyone showing strong signs of it to leave. I sometimes wonder if their attitudes do not aggravate the problem - is tagging "worse"?
K Watson, Stockport, UK
When Mum lived with us I had to keep doors and windows locked and the keys hidden as we lived in a busy city. As a country woman she loved to walk and this put her in real danger. Imagine trying to also bring up two little girls (aged 2 & 5) in these surroundings. A tagging device would certainly have helped - and maybe Mum wouldn't have been so frustrated by her restrictions.
Ann Payne, York
As a retired trained nurse I privately nursed a patient in her own home (on a farm) and daily, as I left the room to make her morning coffee she, (the lovely lady) would go at quite a speed down the farm's lane with me running after her. So, yes I think the idea of a 'tracking' device would be very helpful. Please leave the word 'tagging' for prisoners.
Laura Taylor, Northampton, Northamptonshire
My Gran suffered from dementia and in the period when we just couldn't get anyone to listen or help she used to wander off and not have a clue where she was. It was a nightmare. Tagging, if policed properly, is a wonderful idea and will heighten the safety of this so very vulnerable group.
Abigail Conway, Truro
My Grandmother who is 85, suffers with dementia and wanders off if she gets the opportunity. It does get very frightening for family members when she goes missing. Although she does have day care, she will still wander as she can't be supervised 24 hours a day. Electronic tagging in this circumstance would be incredibly helpful. I appreciate that this could be seen as an infringement of her human rights, but her safety at the end of the day is the most important thing.
David Winecor, Leeds, UK
My Father had Alzheimer's and passed away 5 years ago. He went "wandering" several times. My parents live in north London and my dad was once found in Kent. To this day we don't know how he managed that. I think tagging is a fantastic idea, I remember how panicked, fearful and worried my family were when he disappeared, having to call the police etc.
A tagging system would certainly reassure the families and carers of an Alzheimer's sufferer. How well it would work in practical terms for the person concerned will be variable. My Mum, who has Alzheimer's, is now in a home but her reaction to anything new (such as a plaster cast when she broke her arm) was to try to rip it off, as she couldn't understand it's purpose. It might work for some, but not for all.
Sue Sandy, Rainham, Kent
My Father had Alzheimer's and it runs in the family so there is a chance I will get it. I would certainly be in favour of having one on my person if I did eventually contract the disease. I am 53 years old at present.
Geoff Tucker, Pilley, Hants
My father who sadly passed away in 2004 had Alzheimer's and would sometimes go out by himself, which was very worrying for all of us. Tagging him wouldn't have solved the problem however, it would have given us reassurance that we could find him if he did get out. I think it is a good idea.
Marie, Acton, London
My late Mother in Law had Alzheimer's and wandered, electronic tagging would have saved family members a great deal of worry as she regularly disappeared and was brought home by the police on a number of occasion and once by Blackpool Corporation as she had got on a bus.
Steve Prosser, Bradford. UK