Three years after the Millennium Dome closed, it’s hard to recall the fuss that once surrounded the country’s most expensive visitor attraction. But the children of Chadsgrove school will never forget their visit in September 2000, when the Dome lived up to its hype and they really did have “one amazing day”.

So began the story of how, with a bit of luck, some cheek and a lot of goodwill, the school in the Midlands became the testing ground for what could be one of the most exciting technological innovations in special education. Chadsgrove, a special school in Worcestershire for children with varying degrees of physical disability, has something of a reputation for adventure; pupils regularly engage in outdoor pursuits and go on holidays abroad. So when 50 pupils and assorted staff and helpers set off from Bromsgrove for Greenwich in London that morning, it was nothing out of the ordinary.

The moment that made their trip so remarkable occurred in the Dome’s Playzone, where they came across the Kaleidoscope, a giant version of the child’s toy, with segmented shapes and colours projected on to the wall of a darkened room. The curious thing about the Kaleidoscope, as the children discovered, was that every time they moved, the image changed, and a little piece of music played. If they looked closer, they could see that the tessellated shapes were actually little pieces of them: their faces, arms and legs, dancing around the screen in syncopated patterns.

The children were entranced. Deputy head Gill Clerici remembers the effect it had on one boy in particular. “He was usually a very restless child,” she says. “But we noticed that it had a very calming effect on his behaviour.”

The party returned to Bromsgrove with happy memories of their day out. Gill Clerici had one special recollection: of the Kaleidoscope and the effect it had on her pupils. “I was always taught that if you don’t ask you don’t get,” she says, so a few weeks later she sent a “slightly cheeky” letter to the New Millennium Experience Company (NMEC), the company that ran the Dome. “We thought the Kaleidoscope was wonderful,” she wrote. “We wondered whether we could have one.”

The NMEC couldn’t agree to Ms Clerici’s hopeful request; it was obliged to dispose of all the Dome’s contents at auction to recoup as much as it could of the millions of pounds of public money that had been spent on the project. But it forwarded Chadsgrove’s request to the Land Design Studio, the company that had created the Playzone.

Land Design, a specialist in interactive educational technology, was delighted its exhibit had been so well received. But legally the Kaleidoscope belonged to Kenji Mase, the Japan-based designer who had programmed the unique software behind it. When Peter Higgins, director of Land Design, approached him with Chadsgrove’s proposal, Mr Mase agreed to “donate” his software to the school.

Mr Higgins sensed the makings of a good story, so he called Radio 4‘s Today programme. After 12 months of almost non-stop bad news about the Dome, Today journalist Sanchia Berg was only too glad to get a “good news” story, and her report was broadcast on the last day of 2000.

Peter Jost, a world-renowned engineer and former government adviser on science, heard the item on his way to work that morning, and offered to buy the Kaleidoscope for Chadsgrove. After lengthy negotiations, the machine was finally purchased for pound;10,000 and installed in the school’s multisensory room in the spring of 2001.

The Kaleidoscope consists of a small CCTV camera fixed to the wall of the room, a video projector hanging from the ceiling, and a computer installed with Kenji Mase’s program. The way it works - and the effect it has on pupils - is less straightforward. At one level, it’s a wonderful amusement; there’s something of the fairground about its spinning colours and musical chimes.

At another, like most of the resources in Chadsgrove’s impressively kitted-out multisensory room - recently extended and refurbished to the tune of pound;130,000 - it can be used to teach children about simple cause and effect. But the Kaleidoscope offers something else beyond the bubble tubes and fibre optic curtains.

Three years after it was installed, Angela White, the school’s head of IT, is still finding new uses for the technology. It has expanded the curriculum in PE, dance and art. It has even taught one visually impaired girl the meaning of the word “still”. “Because she couldn’t see she didn’t know what ‘still’ was,” says Ms White. “But she learnt because, every time she moved, it made a noise.” The Kaleidoscope “added a dimension”, she says. “It makes things more interesting and exciting, it’s something to motivate them. The interactivity is unbelievable.”

The CCTV camera can be calibrated to pick up the slightest movements, and transform them into dazzling, multicoloured displays of light and sound.

This offers profoundly handicapped children an involvement that was previously unavailable to them. “They might not realise they are learning because they are so busy exploring,” says Ms White. “But if they think, ‘I can see me up there, and it’s me that made me come up there’, that control, that motivation, is really exciting and encouraging for them. It opens their eyes to the world and the fact that they can control elements of it.”

Richard Aust, Chadsgrove’s headteacher, says his pupils have gained new entry points to the sensory curriculum. “It has created new avenues of learning for our children. And for staff, it has broadened their horizons and the scope of work they can do with children who have got severe physical problems.”

Ms White insists that while to the untrained eye the multisensory room can feel like a chill-out area, clever use of the Kaleidoscope and other resources make it just as important educationally as a classroom. However, she adds: “You have to be cautious about claiming real learning benefits.”

Now, thanks to a grant of pound;132,775 made by the National Endowment for Science Technology and the Arts (Nesta) to Land Design, these benefits will be properly researched and the Kaleidoscope could become available to many more children with special needs. Chris Abbott, senior lecturer in ICT and education at Kings’ College London, a consultant on the project, believes a PC version should be available in a couple of years. It cost more than pound;100,000 to create and make the original Kaleidoscope, but Mr Abbott expects the online version to cost just a few thousand pounds.

Peter Higgins of Land Design is glad the Kaleidoscope has found a home and is hopeful it can have wider applications. “When I saw it installed and how children were using it I thought, ‘We can take this further’,” he says. But he is sceptical about the wholesale adoption of technology such as whiteboards in the classroom. “It slightly depresses me, the acceleration in the use of teaching aids in schools,” he says. “Technology is running ahead of itself. It’s leaving behind the personalisation of teaching. We need to slow down and see the best application of technology in some meaningful way.”

The Kaleidoscope, a one-off experimental entertainment that was nearly consigned to the scrapheap, could - almost by accident - become the most significant development in ICT in special needs for years.

Chadsgrove school, tel: 01527 871511; www.chadsgroveschool.co.ukLand Design Studio, tel: 020 8332 6699; www.landdesignstudio.co.uk