Mechanical attachment and reliable control are two of the biggest challenges in artificial limb replacement. A multidisciplinary group of engineers and surgeons say they have solved these problems by developing a human-machine interface that allows the prosthesis to be comfortably attached via osseointegration (OI) while enabling electrical connection with the nervous system via electrodes implanted in nerves and muscles. The original participant has used the system for a number of years.
The research was led by Max Ortiz Catalan, PhD, head of neural prosthetics research at the Bionics Institute in Australia and founder of the Center for Bionics and Pain Research in Sweden.
The participant, Karin, experienced a right transradial amputation more than 20 years ago and has endured phantom limb pain since then. In addition to her intractable pain, she found that conventional prostheses were uncomfortable and unreliable. After receiving the technology as part of Ortiz Catalan’s research, she was able to wear a functional prosthesis comfortably all day. The higher integration between the bionics and her residual limb also relieved her pain.
“Karin was the first person with below-elbow amputation who received this new concept of a highly integrated bionic hand that can be used independently and reliably in daily life. The fact that she has been able to use her prosthesis comfortably and effectively in daily activities for years is a promising testament to the potential life-changing capabilities of this novel technology for individuals facing limb loss.
“Our integrated surgical and engineering approach also explains the reduction in pain, as Karin is now using somewhat the same neural resources to control the prosthesis as she did for her missing biological hand.”
Treatment and prevention of post-amputation pain is another goal for Ortiz Catalan’s team.
Rickard Brånemark, MD, research affiliate at MIT, associate professor at Gothenburg University, and CEO of Integrum, led the OI surgery.
“By combining osseointegration with reconstructive surgery, implanted electrodes, and AI, we can restore human function in an unprecedented way. The below-elbow amputation level has particular challenges, and the level of functionality achieved marks an important milestone for the field of advanced extremity reconstructions as a whole.”
The nerves and muscles in the residual limb were rearranged to provide more sources of motor control information for the prosthesis. Paolo Sassu, MD, conducted this part of the surgery that took place at the Sahlgrenska University Hospital in Sweden. Sassu is with the Istituto Ortopedico Rizzoli in Italy, and the Center for Bionics and Pain Research in Sweden.
The robotic Mia Hand, developed by Prensilia, featured unique motor and sensory components that allowed the user to carry out 80 percent of her activities of daily living.
“The DeTOP project, funded by the European Commission, offered a great opportunity of collaboration, which made possible the consolidation of state-of-art prosthetic and robotic technologies available in our institutions, that may have a terrific impact on people’s life,” said Coordinator Christian Cipriani, PhD.
The study, “A highly integrated bionic hand with neural control and feedback for use in daily life,” was published in Science Robotics.
Editor’s note: This story was adapted from materials provided by Sant’Anna School of Advanced Studies.
