New bionic arm has more movement

ROBOTIC arms that can be controlled by thoughts will be available in three years, according to scientists.

The new arms represent a breakthrough because they allow a wider range of movements than existing prosthetics.

Currently, robotic arms are controlled by the amputee twitching the muscles in the stump of their amputated limb.

This only allows limited moving because the muscle connected to the nerves has been damaged by the amputation.

But the latest technique rewires the existing nerves running from the spine to a new, intact muscle in the chest or biceps. To control the robot arm, the patient has to think they are moving a phantom limb.

By imagining an action, such as pinching two fingers together, the signal is carried by the nerves to the muscle.

Because the muscle is intact, rather than damaged from amputation, the patient is able to signal a much wider range of movements than would be possible previously.

These include opening and closing the hand, rotating the wrist and moving the arms up and down. Electronic sensors on the skin surface pick up the signals, which then control the robotic arm. It is hoped more commands could be programmed into the robotic prosthetic, allowing more actions.

Dr Dario Farina, based at Imperial College London, and colleagues in Europe, Canada and the US, led the research.

The researchers carried out lab-based experiments at the University of Vienna with six volunteers who were amputees, either from the shoulder down or just above the elbow.

After physiotherapy training, the amputees were able to make a more extensive range of movements than would be possible using a muscle-controlled prosthetic. The researchers came to this conclusion by comparing their research with previous studies, the journal Nature Biomedical Engineering reports.

Dr Oskar Aszmann, of the Medical University of Vienna, said the researchers had “decoded the language of movement control”. – Daily Mail