Surgeons have revealed an innovative bionic hand engineered to enable unparalleled singular finger movement.
This remarkable achievement marks a leap forward within the world of prosthetics, bringing new-found hope to those patients seeking enhanced dexterity and more control.
For the first time, a person with an arm amputation can control every finger of a bionic hand as if it was their own – thanks to novel surgical and engineering advancements merging humans with machines.
The image above shows the patient wearing a prosthetic arm directly attached to the skeleton with an X-ray showing the implanted sensors and the neuromusculoskeletal interface that allows him to control individual fingers of a bionic hand.
By focusing on perfecting these individual finger movements, the team behind the new development aims to restore a sense of natural motion and empower users with greater flexibility in performing everyday tasks, such as pouring a jug of water, picking up a piece of paper, gripping a ball and using a screwdriver.
This is because the bionic hand offers ‘mindful control of thumb, index finger, middle/ring/little finger and wrist’, ‘simultaneous of thumb and index to pinch as well as wrist rotation’, ‘mindful thumb flexion and then simultaneous flexion of individual fingers’ as well as ‘simultaneous control of individual fingers to open and close the hand’.
Surgeons collaborated with engineers to improve the patient experience of prosthetic limbs.
They improved control by rewiring nerves to muscles in a ‘distributed and concurrent manner’, incorporating the embedding of sensors during surgery. Once implanted into the neuromuscular constructs, the sensors are connected to the electronic system of the prosthesis using osseointegration. AI algorithms then decode motor commands, allowing bidirectional communication with the prosthesis and providing direct skeletal attachment.
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.
He said: ‘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 can 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. AI algorithms take care of the rest.’
Currently, the drawbacks of prosthetic limbs include limitations in movement, difficulties with control and reliability.
This latest breakthrough means users may master everyday tasks previously not achievable.
The team believes that by reconfiguring the residual limb and integrating sensors and a skeletal implant, they have boosted the capabilities of the bionic hand.
The team reported: ‘We found that the transferred nerves effectively innervated their new targets as shown by a gradual increase in myoelectric signal strength. This allowed for individual flexion and extension of all five fingers of a prosthetic hand by a patient with a trans-humeral amputation.
‘Improved prosthetic function in tasks representative of daily life was also observed. This proof-of-concept study indicates that motor neural commands can be increased by creating electro-neuromuscular constructs using distributed nerve transfers to different muscle targets with implanted electrodes, enabling improved control of a limb prosthesis.’
The study in Science Translational Medicine presents the first documented case of a patient whose body was surgically modified to incorporate implanted sensors that allowed the connection of a hand prosthesis to his neuromusculoskeletal system.
Dr Rickard Brånemark, a research affiliate at MIT, associate professor at Gothenburg University, CEO of Integrum, a leading expert on osseointegration for limb prostheses and who conducted the implantation of the interface, said: ‘It is rewarding to see that our cutting-edge surgical and engineering innovation can provide such a high level of functionality for an individual with an arm amputation. This achievement is based on over 30 years of gradual development of the concept to which I am proud to have contributed.’
To watch the capabilities of the bionic hand, click here
Photo Credit: Zbinden et al., Sci. Trans. Med., 2023./Chalmers University of Technology/Anna-Lena Lundqvist
