A pioneering bionic hand has brought about a remarkable transformation for a 50-year-old Swedish woman who lost her hand in a farming accident. This cutting-edge prosthesis utilizes groundbreaking technology to establish a direct connection with the user’s bones, muscles, and nerves, creating a human-machine interface that enables artificial intelligence to translate brain signals into precise, natural movements. The recipient, Karin, now experiences a limited sense of touch and can individually move all five fingers of her bionic hand with a remarkable success rate of 95 percent.
After two decades of living without her right hand, Karin has regained the ability to perform 80 percent of her everyday tasks. This includes activities like food preparation, object handling, clothing fastening, and operating door knobs or screws. Additionally, since receiving the prosthetic hand, Karin’s excruciating phantom pain, which had previously felt as though her hand was undergoing torment, has significantly diminished, reducing her reliance on medication.
“This has given me better control over my prosthesis, and, above all, it has reduced my pain,” Karin remarked. “I require far less medication today.”
The research team, comprising scientists from Sweden, Italy, and Australia, heralds this achievement as the first instance of a robotic hand with internal electrodes demonstrating long-term viability for amputations below the elbow.
Max Ortiz Catalán, a robotics engineer who led the research at the Bionics Institute in Melbourne, Australia, and the Center for Bionics and Pain Research in Sweden, emphasizes the groundbreaking potential of this novel technology for individuals facing limb loss. He notes that Karin’s successful daily use of the prosthesis over several years is a promising testament to the life-changing capabilities of this technology.
When Karin was initially equipped with this prosthesis three years ago, it was truly one-of-a-kind. At the time, no other hand prosthesis on the market contained embedded sensors. Most available models featured sensory electrodes on the exterior, located just beneath the artificial ‘skin.’
This conventional approach, however, limited the quality and quantity of sensory signals traveling to and from the robotic hand, posing a longstanding challenge in prosthetic technology development.
Over the past decade, Ortiz Catalán has been developing a superior solution based on ‘osseointegration.’ This technique involves implanting a device into a person’s bone, enabling bone cells to firmly encase it.
“When the artificial limb is directly anchored to the skeleton, this integration is so robust that we can attach the artificial limb directly to the bone,” explains Ortiz Catalán in a video.
To establish an interface for the prosthesis, two implants were inserted into Karin’s ulna and radius bones, with a muscle graft from her leg connected to these implants. This provided the severed muscles and nerves in Karin’s arm stump a connection point. Crucially, the muscle grafts contained electrodes to amplify signals to the interface. The direct anchoring of the prosthesis to the bone offers enhanced comfort for patients compared to traditional ‘ball-and-socket’ prostheses. Additionally, because the sensory electrodes are internally embedded within the robotic hand, neural stimulation is consistently and reliably perceived by the hand.
This new technology significantly enhanced Karin’s grip precision, nearly quadrupling her grip accuracy compared to conventional prostheses. The prosthetic hand, named Mia Hand, was developed by the Italian company Prensilia, specializing in robotic and biomedical devices, and was funded by the European Commission.
The Bionics Institute CEO, Robert Klupacs, expresses excitement over the achievements of Professor Ortiz Catalán and his team, particularly in light of the potential for relief from phantom limb pain. Ortiz Catalán is currently working in Ukraine, offering expertise to amputees during the ongoing conflict.
By Impact Lab
