We are talking more and more often about man-machine interfaces. The bionic prosthesis implanted in a 50-year-old Swedish woman, who had her arm amputated 20 years ago following a terrible accident with an agricultural vehicle, it represents the most recent, advanced and effective solution for this type of applications.
A research team led by the University of Gothenburg has developed a revolutionary prosthesis that allows patients who have the use of their hand and part of their arm to move again robotic fingers. The historic result was achieved by implanting electrodes in the nerves and muscles with a process of osseointegration which integrates metal and bone.
The targeted muscle reinnervation (TMR) is a surgical process that involves the selective rerouting of nerves to improve muscle control in certain areas of the body. When a patient undergoes an amputation or surgery that involves the removal of significant portions of a limb, the endings that previously innervated those muscles may be cut or damaged. Targeted reinnervation seeks to rehabilitate the muscle functionallowing the patient to control the new structures more precisely and naturally.
How the bionic prosthesis controlled through the brain and nerves works
The additional step that interested the Swedish patient concerns the development of a man-machine interface that allows the prosthesis to be connected to the skeleton via osseointegration, allowing electrical connection with the nervous system through electrodes implanted in nerves and muscles. The video published on YouTube shows the details of the operation.
Swedish Karin (her full details have not been released) is the first person with a below-elbow amputation to receive the new bionic hand highly integrated that can be used to carry out the most common daily activities.
The neuromusculoskeletal implant to coordinate biological and electronic control
The bionic prosthesis represents the achievement of a series of goals (the study is published in Science): one of the most futuristic has to do with the development of a neuromusculoskeletal implant suitable that allowed you to connect the system biological control of the patient (the nervous system) with the system of electronic control of the prosthesis. Karin explains that after the implant, her pain has significantly reduced compared to the past. Experts justify the phenomenon by explaining that Karin is now using the same ones in some way neural resources to control the prosthetic, as he did with his biological hand long ago.
Il movement of the arms and hands is orchestrated by complex neural circuits involving the central nervous system (CNS) and the peripheral nervous system (PNS). The process of controlling movement is known as “motor control” and involves a series of electrical and chemical signals that occur throughout the nervous system. The human brain obviously plays a fundamental role in controlling movement. The main area involved is the motor cortex, located in the frontal lobe of the brain. This region processes information related to movement and sends signals to muscles via the cortico-spinal pathway. This is why it can be said that the bionic prosthesis is controlled by the brain, supporting the processes that normally occur in the human body.
There is a lot of Europe in the operation that restored the use of an arm and hand to a patient
Although the trial is led by a Swedish team, theEurope is the protagonist. Professor Christian Cipriani, of the Sant’Anna School of Pisa, explained that the DeTOP project (Dexterous Transradial Osseointegrated Prosthesis with neural control and sensory feedback), financed by the European Commission, offered an excellent collaboration opportunity that made the consolidation of the prosthetic technologies e robotics cutting edge.
Doctor Paolo Sassu (Rizzoli Orthopedic Institute Europen e Center for Bionics and Pain Research Swedish), instead, oversaw the surgery for the implantation of the prosthesis. There bionic handin turn connected with the prosthesis fixed on the arm, is called Mia Hand and is developed and built by the Europen robotics company Prensilla, based near Pisa. Mia Hand allows patients to move their fingers freely by establishing an electrical connection with the nervous system.
When the patient thinks about the movement of the fingers, the nerves in the arm are activated and the sensor embedded in the prosthetic hand picks up the electrical signals by moving the human grasping organ accordingly. By combining osseointegration with reconstructive surgery, electrode implantation andartificial intelligence it becomes possible to restore human function in an unprecedented way.
It goes without saying that Karin underwent a certain period of “training” to be able to move her prosthetic arm and hand as desired. This phase involved the use of a computer that guided the patient in managing movement stimuli. Thanks to repeated training, Karin is now able to even judge the hardness of the objects she picks up.
The images in the article are taken from the video by Professor Max Ortiz Catalan et al. (Science Robotics, 2023), head of neural prosthesis research at the Bionics Institute in Australia and founder of the Center for Bionics and Pain Research (CBPR) in Sweden.