Amanda Cooper used to love going to the supermarket and piling her trolley high with chocolate biscuits and pepperoni pizzas - but not any more.
Her supermarket smart card reads the bar codes and sounds out an alert whenever the 30-year-old picks up anything that might contain more than 10 per cent fat. By the time she reaches the check-out, her weekly groceries consist of vegetables, diet soup and wholemeal bread. But she knows she's overweight and that she has no choice - her GP prescribed the card for her.
It is all part of an alarming scenario being painted for life in 2015, when a bewildering array of devices will be used to keep us healthy. At a conference in Birmingham next week, designers will produce their ideas of which gadgets are most likely to be installed on our bodies, in our wallets or throughout our homes to help us live longer, fitter lives.
How many of us would relish the prospect of having our shopping baskets constantly scanned to rule out any fatty products? The Big Brother concept of having your habits examined electronically throughout the day - all in the name of preserving your health - may be more frightening than reassuring.
But such devices are coming into use. 'Telemedicine' is already being used to help specialists to diagnose conditions in clinics hundreds of miles away in remote regions. Companies are also looking to digital technology to enable a patient sitting at home to have their blood pressure and other bodily functions monitored down a phone line, rather than having to travel into the local A&E department.
Jeremy Myerson, a design expert with the Helen Hamlyn Research Centre at London's Royal College of Art, says changing demographic patterns make it essential to look at technologies that will enable people to live much more independently.
'By 2020, it's forecast that more than half the European population will be over 50,' said Myerson. 'At the same time, you have a declining fertility rate. That's going to have a dramatic effect on the way we care for people, and the burden it puts on the NHS.
'Surveillance systems in the home can monitor people and keep them out of institutions. It may seem Big Brotherish, but it's actually about giving people their independence.'
A new generation of consumer-driven products will be unveiled at the Medical Device Technology conference on Wednesday, where speakers will look at the needs of patients who want to be out of their hospital beds as soon as possible. For the first time, the market is being driven by what individuals are prepared to pay rather than by the diktats of the NHS.
'We're already seeing self-testing kits for lifestyle diseases, such as cholesterol, and that is changing people's attitudes to medical information,' said Clive Bray, a Department of Health expert on devices.
'In the past, everything was offered in a hospital, but now we're getting better at allowing people who have a chronic illness or disability to remain at home, providing equipment to help them breathe properly instead of having to be admitted.
'Technology is driving the change, but so is the rising demand from the public for greater control over their healthcare.'
One design consultancy firm, Pearson Matthews, looked at four very different scenarios designed to illustrate the future of healthcare. For the conference, they have used actors to pose as the types of people who will be helped by the technology.
'The underlying theme is that of empowering people. We have the opportunity to define what we want from our healthcare providers and fitting it to our lives,' said spokesman Matthew Young. 'People will have lots of ways of entering the healthcare system, and the technology will have to fit into their daily routines.'
