Robotic prosthesis that mimics arm movements

This is a technology that allows you to control a prosthesis using your thoughts. The device interprets electrical signals sent by motor neurons

There's an ambitious project that bioengineering professor Dario Farina of Imperial College London hopes to accomplish: helping people who have undergone limb amputations better control their prostheses. How? Through sensors connected to the nervous system.

As the doctor says, when a limb is amputated, a portion of the muscles and nerves that prevent the person from receiving enough impulses to control the prosthesis are also taken away. This means that the disabled person has a limited amount of movement. What to do? The solution may be to use prostheses that process motor neurons directly. These are neurons that are used by the nervous system to control the movement of muscles. The team of scientists has therefore developed sensors that operate using electrical signals sent by spinal motor neurons.

How the technology works

The technology created thanks to the study of the research group of Imperial College works by interpreting the signals coming from the spinal nerves and transforms them into commands. To control the mechanical arm, patients will have to think about moving the prosthesis, imagining that they are performing simple maneuvers. To test the sensors, the team involved six people who had undergone arm-to-elbow amputations. The patients first underwent surgery at the Medical University of Vienna where their peripheral nervous system, which is linked to arm and hand movement, had to be re-routed to a portion of healthy muscles: biceps and chest. The results were comforting: people were able to move the prosthesis and open and close the robotic hand.

Always more sensitive prostheses

How was the technology created? The team mapped and decoded some information from cells in the patients' nervous systems. The data was then compared to that of able-bodied people. The research team's ultimate goal is to develop sensors that are able to fully replicate the functioning of an arm on a prosthesis. To do so, the scientists need to fully decode the electrical signals sent by motor neurons.