|8 February 2017|

London

Thinking about pinching two fingers together triggers a new robotic prosthetic arm to do just that.

Scientists – led by Dr Farina, from the Department of Bioengineering at Imperial College London, have developed sensor technology for a robotic prosthetic arm which interprets electrical signals sent from spinal motor neurons and uses them as commands. To control the prosthetic, the patient simply has to think like they are controlling a phantom arm.

Volunteers were able to use the technology to move the elbow joint and do radial movements – moving the wrist from side to side – as well as opening and closing the hand. This means that the user has all basic hand and arm functions of a real arm.

Dr Farina said: “When an arm is amputated the nerve fibres and muscles are also severed, which means that it is very difficult to get meaningful signals from them to operate a prosthetic. We’ve tried a new approach, moving the focus from muscles to the nervous system. This means that our technology can detect and decode signals more clearly, opening up the possibility of robotic prosthetics that could be far more intuitive and useful for patients. It is a very exciting time to be in this field of research.”

In a study published in the journal Nature Biomedical Engineering, the team said detecting signals from spinal motor neurons in parts of the body undamaged by amputation, instead of remnant muscle fibre, means that more signals can be detected by the sensors connected to the prosthetic. This means that ultimately more commands could be programmed into the robotic prosthetic, making it more functional.

The next step will involve extensive clinical trials with a much wider cross section of volunteers so that the technology can be made more robust. With researchers suggesting the current model could be on the market in the next three years.