By Jane Elliott
BBC News Health Reporter
People paralysed by spinal cord injuries could soon be able to go out cycling.
Cycling on the recumbent tricycle
Scientists say the tricycle, which works by stimulating the legs electrically, will not only provide a means of transport and recreation, but should also stop muscle wastage and could provide more mobility.
FES (functional electrical stimulation) tricycling has been developed by teams from University College London (UCL) and the University of Glasgow.
The technique involves stimulating paralysed muscles by passing short pulses of current through electrodes on the skin.
A stimulator synchronizes the stimulation with the pedal position while the person has a 'throttle' to control how much stimulation is applied - rather like a motor bike with the legs as the engine.
Professor Nick Donaldson, said the device - dubbed the 'recumbent tricycle' - would be available within a year.
He said it would help get people back into exercising safely - an option not always open to them at present.
"The arms and shoulders were not evolved for wheelchair sports," he told the BBC News website.
"More than half wheelchair athletes over 40 years old suffer from damaged joints."
Professor Donaldson said the only current way to exercise the paralysed muscles was by electrical stimulation.
But just stimulating the muscles was not much fun and made people reluctant to exercise.
The new tricycle, which can be used at home to train the muscles while stationary, or for recreation outdoors, should provide a much more tempting prospect.
"We hope that these people with Spinal Cord Injuries (SCI) will find that this gives them a pleasant way to exercise their legs and become healthier.
"We want to create a system that they can use from home and that they will want to use because it is fun."
Professor Donaldson said it was important for people with SCIs to try to exercise their legs, as inactivity not only led to muscle wastage, and bone loss, but also to poor circulation.
He is hopeful that pioneering work at the Royal National Orthopaedic Hospital in Stanmore, Middlesex, may eventually make the tricycle even more effective.
Showing the site of implanted electrodes
People with SCIs often face difficulties that cannot be assisted by surface stimulation - such as control of their bodily functions.
It is possible to insert implants to control functions such as emptying the bladder - but this involves cutting some sensory nerves.
At the Royal National Orthopaedic Hospital trials are underway to test an alternative that causes no nerve damage at all.
It works by placing electrodes on the nerves as they emerge from the spinal cord.
Professor Donaldson said preliminary work suggests the same technique could be used to improve mobility for people using his tricycle.
John Cavanagh, head of spinal research at Bramley Business Centre, Guilford, said the design would be welcomed by people there were already a number of stationary bikes - but that this design would allow people with SCIs greater mobility.
"The idea is certainly very good and will enable people to get fit and propel themselves around outside.
"Theoretically, it is quite a good idea as people with paralysis of the limbs sometimes see their muscles waste away and this will keep them working."
The tricycle is just one of a number of exhibits on display at the 'Celebration of UK Engineering Research and Innovation'.
The exhibition, in Docklands, London brings together a group of people involved in all aspects of UK engineering and are leading their fields in world class research.
Other exhibits include a swim buoy designed to give support to people with spinal disabilities enabling them to swim or float in the pool.
Designer Paul Borkowski, a graduate of Industrial Design Engineering on a combined course with Imperial College and Royal College of Art, worked closely with paraplegics and tetraplegics, to see the problems they have swimming.
The swim buoy supports the spine
One, a former diver with the Royal Navy who had been paralysed in a car accident, told Paul that it was impossible for them to swim on their fronts without their heads flopping into the water.
He said they could not swim on their backs because their disability prevented their backs from making the arch needed to swim.
So he created his swim buoy to provide support in the shoulder to enable the spine to assume the correct position.
Paul hopes to do further tests on the design before approaching a manufacturer to get his device into production.
Other designs, show how imaging can be used to help surgeons carrying out orthopaedic and heart operations.
King's College London, will be exhibiting a device that uses ultrasound technology to build up a 3D image before surgery, cutting out the need for a CT scan.
They will also demonstrate a device that uses an MR scanner along with X-rays to create better information for surgeons treating heart rhythm abnormalities.
Lucy Brady, from Engineering and Physical Sciences Research Council, said the exhibition showed how engineering could be used to advance healthcare.
"Many aspects of healthcare have been influenced by engineering research from the preventative and diagnostic benefits of targeted drug delivery, sensors and medical imaging to the treatment that the operating room of the future will offer with its computer assisted surgery.
"It is impossible to underestimate the significance of engineering and its ongoing impact on the world we live in."