The way surgical amputations are performed has not changed much in decades, while there has been a great deal of progress in prosthetic technologies, interfaces, and rehabilitation. One modern problem that surgical amputations fail to address is the inability of neural electrodes to sense signals because the nerves are simply cut and neuromas form over them. Another problem is that antagonist muscle pairs, such as a bicep and tricep, are frequently no longer act in sync, creating control issues, hindering balance, and other physiologic difficulties. They also make it difficult to sense the state of a prosthetic connected to a limb with disconnected antagonist muscle pairs.
Researchers at MIT have now developed an “agonist-antagonist myoneural interface (AMI), a unique surgical paradigm for amputation,” according to a study published in journal Science Robotics. This essentially involves grafting pairs of muscles from another part of the body and interfacing them with existing nerves on the severed limb. This creates a feedback loop just like in antagonist muscle pairs, something that a prosthetic can tap to give its wearer a sense of what it’s doing. Using the technique, the MIT team demonstrated in laboratory rats that the animals retained muscle-tendon sensory feedback via the nervous system.
Pushing the idea further, the researchers used the muscles as a control mechanism for a prosthetic device, converting the electrical signals generated by the grafted muscles into signals that tell a mechanism how to move. The next steps will involve trying this out on human patients, potentially opening an exceptional new opportunity to improve the capabilities of prostheses.
Study in Science Robotics: On prosthetic control: A regenerative agonist-antagonist myoneural interface…
Via: MIT…