By Kate Foster
A TEAM of Scottish scientists has produced an artificial arm that is more powerful than the real thing. The superhuman arm, for patients who need an artificial limb, can lift heavier weights than the average person is capable of and will only fatigue when its batteries run out.
The i-Limb System arm has been developed by researchers at prosthetics firm Touch Bionics, which last year launched the most advanced artificial hand in the world. The Livingston-based firm specialises in hi-tech limbs for patients who have undergone amputations or were born with limbs missing. The researchers say their new arm is capable of repeatedly lifting a weight of 10kg up above head height and could do so all day, compared with the average human being who would tire within minutes. The wrists could rotate 360° and anyone using it could perform hundreds of push-ups.
However, the sheer power of the limb means its creators are faced with the problem of deciding which patients could be trusted to use it safely, as it has the potential to be used as a weapon.The arm was developed by David Gow, director of rehabilitation engineering services at NHS Lothian, who has worked with hundreds of patients at the South-east Mobility and Rehabilitation Technology Centre at the Astley Ainslie Hospital in Edinburgh.Gow is also the director of technology for Touch Bionics, which researches and develops state-of-the-art technology.
He told Scotland on Sunday that the arm is at the prototype stage and is undergoing further fine-tuning in order to make it available to patients.He said: "The i-Limb system is better than a human arm. It is faster and can lift heavier weights than a human arm. It also looks good, has smooth movement, and operates with less noise than existing prosthetic arms. The technology is new and evolving. "However, we might have to scale the power down to make it suitable for everyone. With something that has a better than human performance, our challenge is ethical. "A patient would have the potential to hurt themselves or other people with it as it is actually better than a human arm. It could do damage. "We have got to take safety very seriously. You have to attach it to the patient's body and that could cause damage if the weight is too heavy. It could snap their ribs. And it could be pretty scary flapping about."
Scientists have spent years researching how to create robots that can surpass human performance. The i–Limb System is the latest in a long line of bionic body parts to have been created in laboratories just two or three decades after they were merely the stuff of science fiction.
The arm, which is worn in a harness, is controlled by electrical signals that come from the user's own body. Electrodes are placed on the skin on the user's chest which pick up minute signals from the muscles. The user is taught how to move these muscles to send electrical signals which control motors inside the arm such as wrist rotation and elbow movement. It is powered by lithium-ion batteries which can be recharged overnight. The i-Limb System will be covered in a realistic cosmetic skin.
Wednesday, January 9, 2008
By Kate Foster