The research team at Chalms University of Technology in Sweden has achieved unprecedented precision control of prosthetics – the ability to control every finger of a biomimetic prosthetic limb. They dissected the nerves around the stump and redistributed them to new muscle targets used as biological amplifiers, allowing the bionic prosthetics to receive more signals, allowing users to freely control many bionic joints. The paper published in the 12th issue of Science Translational Medicine explains how the transferred nerves gradually connect to the new host muscle, bringing new hope to amputees worldwide.
Patients who wear artificial limbs in the laboratory of Bionics and pain research center.
Image source: Chalms Institute of Technology, Sweden
Prosthetics are the most common solution to replace lost limbs. However, they are difficult to control and their actions are limited. The remaining muscles in the residual limb are the preferred source of control for biomimetic prosthetics. This is because the patient can contract the muscle at will, and the electrical activity generated by the contraction can be used to tell the prosthetic limb what to do, such as opening or closing. However, if there were amputations above the elbow, the patient would not have many muscles to command so many biomimetic joints, such as five “fingers”.
New research suggests that reconnecting nerves to different muscle targets in a distributed and parallel manner is not only possible, but also helps improve prosthetic control.
Prosthetic limbs are usually connected to the body through an interface, but their socket can compress the residual limb, causing discomfort and mechanical instability. Another option is to implant titanium implants into the residual bone to firmly fix it, which is called bone integration. This bone connection can achieve a comfortable and more effective mechanical connection between the prosthetic limb and the body.
Schematic diagram of the surgical process, creating an electrical neuromuscular structure for controlling the prosthesis. The electrode and bone integration interface provide electrical and mechanical connections to the prosthesis, respectively.
Image source: Science Translational Medicine
The research team underwent surgery on a patient with an arm amputation. They combine new microsurgical techniques with complex implanted electrodes, which provide single finger control and sensory feedback for prostheses. Among them, the electrode and bone integration interface provide electrical and mechanical connections to the prosthesis, respectively.
As a result, patients with arm amputations can manipulate each finger of the bionic prosthetic limb for the first time just like their own fingers.
(Source: Science and Technology Daily)
Post time: Jul-22-2023