Surgical and engineering innovations enable unprecedented control over every finger of a bionic handDate: July 12, 2023
Source: Chalmers University of Technology
Summary: For the first time, a person with an arm amputation can manipulate each finger of a bionic hand as if it was his own. Thanks to revolutionary surgical and engineering advancements that seamlessly merge humans with machines, this breakthrough offers new hope and possibilities for people with amputations worldwide. A study presents the first documented case of an individual whose body was surgically modified to incorporate implanted sensors and a skeletal implant. A.I. algorithms then translated the user's intentions into movement of the prosthesis.
Prosthetic limbs are the most common solution to replace a lost extremity. However, they are hard to control and often unreliable with only a couple of movements available. Remnant muscles in the residual limb are the preferred source of control for bionic hands. This is because patients can contract muscles at will, and the electrical activity generated by the contractions can be used to tell the prosthetic hand what to do, for instance, open or close. A major problem at higher amputation levels, such as above the elbow, is that not many muscles remain to command the many robotic joints needed to truly restore the function of an arm and hand.
A multidisciplinary team of surgeons and engineers has circumvented this problem by reconfiguring the residual limb and integrating sensors and a skeletal implant to connect with a prosthesis electrically and mechanically. By dissecting the peripheral nerves and redistributing them to new muscle targets used as biological amplifiers, the bionic prosthesis can now access much more information so the user can command many robotic joints at will (video:
https://youtu.be/h1N-vKku0hg).
The research was led by Professor Max Ortiz Catalan, Founding Director of the Center for Bionics and Pain Research (CBPR) in Sweden, Head of Neural Prosthetics Research at the Bionics Institute in Australia, and Professor of Bionics at Chalmers University of Technology in Sweden.
"In this article, we show that rewiring nerves to different muscle targets in a distributed and concurrent manner is not only possible but also conducive to improved prosthetic control. A key feature of our work is that we have the possibility to clinically implement more refine surgical procedures and embed sensors in the neuromuscular constructs at the time of the surgery, which we then connect to the electronic system of the prosthesis via an osseointegrated interface. A.I. algorithms take care of the rest."
Prosthetic limbs are commonly attached to the body by a socket that compresses the residual limb causing discomfort and is mechanically unstable. An alternative to socket attachment is to use a titanium implant placed within the residual bone which becomes strongly anchored -- this is known as osseointegration. Such skeletal attachment allows for comfortable and more efficient mechanical connection of the prosthesis to the body.
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Source:
https://www.sciencedaily.com/releases/2023/07/230712165138.htm
