Chas A Blatchford & Sons Ltd for the Echelon hydraulic ankle-foot for amputees

Echelon is the world's first self-aligning ankle-foot prosthesis, using hydraulics to enable amputees to walk far more easily. The new foot adjusts smoothly to inclines and the hydraulics distribute the load in a similar way to natural muscles. Patients say they no longer have to think consciously about walking, whereas a conventional ankle-foot prosthesis requires constant awareness and postural adjustments as it cannot flex in a natural way, particularly when walking up or down a slope. Thanks to Echelon, activities such as cycling, dancing, hill-walking and even paragliding have become far more accessible and comfortable for patients. Some injured Forces personnel have been able to return to combat using the new prosthetic foot.

Blatchford's engineers use gait analysis of the whole leg-ankle-foot system to study the way Nature solves the problem of foot flexion. They combine sophisticated hydraulic dampers with carbon fibre springs to mimic natural muscle control. The whole body benefits as it does not have to compensate so much for an unnatural gait, helping to minimise strain on the back. Echelon draws on the ability of the nervous system to sense body position in space - an attribute called proprioception - which is key to the design of successful prostheses.

In the 18 months since it was launched, over 1,300 Echelon feet have been fitted, generating a turnover of over £2.5 million for Blatchford, which is one of the world's largest prosthetics manufacturers, celebrating its 120th anniversary this year.

Royal Academy of Engineering

A prosthetic foot that mimics the muscle actions of real feet has been short-listed for the UK's top engineering prize.
Four projects are on the shortlist for the Royal Academy of Engineering MacRobert Award, worth £50,000.
Other projects on the shortlist include a better landmine detector, high-speed satellite broadband and a greener way to make acrylic plastic. The overall winner of the prize will be announced on 7 June.

Unlike other false feet, the Echelon prosthetic foot and ankle uses hydraulics to help it align itself.
Before now walking with many types of prosthetic foot has been a conscious process in which an amputee must think about where and how to put their foot down. By contrast, the carbon fibre springs and hydraulic dampers in Echelon combine to put it in the right position as it is put down to take a step. This means it can cope better with inclines and the hydraulics are arranged so they spread the load of the body like real muscles. Some soldiers fitted with Blatchford's Echelon prosthetic have been able to return to combat duties.

Also nominated is the Minehound mine detector developed by Cobham Technical Services which uses two sensors to do a better job of finding buried ordinance than traditional metal detectors. It is estimated that for every landmine found, 150 false alarms have to investigated - a time-consuming and risky exercise. Minehound produces only 20 false alarms for each mine found thanks to its combination of ground penetrating radar and metal detector. Sophisticated onboard software interprets signals to help an operator separate real mines from false alarms.

Inmarsat is also on the shortlist for the award for its creation of the Broadband Global Area Network service that offers broadband speeds of 500kbps and simultaneous voice anywhere in the world.

Lucite International is nominated for its Alpha process that removes much of the toxic chemicals from production processes of acrylic plastic.

First presented in 1969, the MacRobert Award honours engineering innovation. Former winners include the Beijing Olympics Water Cube and a retinal imager that can help spot eye defects quicker than many other diagnostic methods.

Overview of the 4 Nominees

Four top engineering teams have been selected as the finalists for Britain's biggest engineering prize -The Royal Academy of Engineering MacRobert Award. Contenders for the £50,000 prize for 2010 are: the world's first self-aligning ankle-foot prosthesis, helping amputees walk more naturally; a pioneering new way to detect landmines that minimises false alarms; the global mobile satellite communication system used by all major broadcasters; anda new, greener chemical production process for methyl methacrylate, the key ingredient in acrylic plastics.

BBC Website