Bionic man

While covering the Iraq war, BBC producer Stuart Hughes lost his leg. His new prosthetic foot is so advanced, it may even allow amputee soldiers back into battle.

"Every evening, before I switch off the bedside light, I take my right leg off and plug it into the mains. I am a below-knee amputee. I lost my leg in 2003 after stepping on a landmine while covering the war in Iraq for BBC News. A few weeks ago, I became one of the first people in the UK to be fitted with the world's first "intelligent" prosthetic foot."

"The word "bionic" inevitably conjures up memories of the 1970s TV series, the Six Million Dollar Man. Unfortunately, my prosthesis doesn't enable me to leap over a wall with a single bound or run faster than a speeding bullet. Rather, it uses sensors and a built-in microprocessor to mimic some of the actions of a human foot. The Proprio Foot is one of a new range of bionic artificial limbs designed by Ossur, a prosthetics company based in Iceland."

"The sensors detect whether the user is walking on level ground, going uphill or downhill or climbing steps," says Ossur's Richard Hirons. "Every type of terrain has a distinct 'signature' which the software controlling the foot is able to interpret. When the microprocessor recognises a change in terrain, it instructs a very accurate motor to automatically adjust the angle of the foot in preparation for the next step."

Researchers have been connecting man and machine since the 60s when they first began using electrodes attached to the body to direct motorised arms to move and bend.

But Saeed Zahedi, visiting Professor in Prosthetics at the University of Surrey, says more and more computer-controlled devices are beginning to emerge from the laboratory and on to the marketplace.

"The technology is a lot cheaper now," Professor Zahedi says. "Electronic components that would have cost hundreds of pounds 10 years ago now cost just a few pounds. Computer-controlled devices can be programmed and are much more flexible, which is why designers are choosing them instead of complicated and expensive mechanical devices."

One market keeping a close eye on developments is the military, which has seen a rise in the number of amputees among its ranks. Advances in battlefield medicine and better protective equipment mean that many soldiers who would once have died are now surviving, but are returning from war zones with horrific injuries.

Hundreds of soldiers serving in Iraq and Afghanistan have lost limbs, many due to roadside bombs and improvised explosive devices. Once, a soldier who had lost a limb in battle would have been pensioned off or transferred to a desk job. Now, though, some are being passed as fit for duty and are being allowed to return to the frontline.

"The mindset, even as early as five years ago, was if a soldier had impairments such as an amputation, they are unfit and they may be at risk to others around them if put in a combat situation. That has changed," says Colonel Daniel Garvey, Deputy Commander of the US Army Physical Disability Agency. "If a soldier wants to remain on active duty, we are going to find a job for him. That is a cultural change for us."

But Grania Hyde-Smith, from the Limbless Association, a charity which provides advice and support to amputees, urges caution.

She says the cost of the current generation of bionic limbs - up to ?60,000 for some powered knee systems - puts them beyond the reach of many users. Ms Hyde-Smith wants more research to be carried out into whether the benefits justify the hefty price tag.

"Bionic technology definitely offers new prospects that weren't available before, but I don't think we should get carried away just yet," she says. "People are reading about the new technology and are getting very excited about it -- and rightly so. But if you speak to health care professionals and prosthetists they say it's still very early days. They're not sure the new systems have been tried and tested sufficiently."

Some researchers believe the current generation of bionic limbs is just the beginning. They are working towards the day when man and machine are seamlessly integrated. "There's bound to come a time where the concept of the bionic man stops being just science fiction," says Professor Zahedi. "Promising work is taking place with limb transplants. One day it may be possible to create hybrid limbs which combine human tissue with electromechanical devices. Experiments with neural implants are also progressing quite rapidly, connecting the nervous system to external devices. What we're seeing at the moment is just the tip of the iceberg."

Perhaps one day an electronically-enhanced human being - "better, stronger, faster" as the opening titles of the Six Million Dollar Man put it - will be a reality. But bionic technology is already bringing benefits for amputees like me - just so long as we don't forget to recharge our batteries.