The world is edging closer to creating fully functional prosthetic limbs with the first clinical bionic attachment connected directly to the nervous and skeletal systems. Incorporating artificial intelligence (AI), the “Mia Hand” has restored about 80 percent of daily use to the user’s hand and fingers.
Led by Professor Max Ortiz-Catalan, head of neural prosthetics research at Australia’s Bionics Institute in Australia, a team of engineers and surgeons across the globe have developed the new kind of prosthetic-body integration, which has provided a Swedish amputee patient with a limb almost as functional as the hand she lost in a farming accident. What’s more, it’s held up to constant daily use for more than three years.
Attachment and user control of prosthetic limbs remain two huge hurdles in this field of medicine. In an effort to combat these common issues, researchers developed a human-machine interface that would comfortably attach the artificial structure to the patient’s skeleton through the process of osseointegration. Then, electrodes implanted in nerves and muscles could also be attached to tap into the body’s nervous system. Osseointegration is the direct structural and functional link between the patient’s living bone and the artificial implant —in this case, the bionic limb structure made of titanium.
“The biological integration of titanium implants into bone tissue creates opportunities to further advance amputee care,” said Rickard Brånemark, associate professor at Gothenburg University and founder of biotech implants company Integrum. “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 research team was able to design a neuro-musculo-skeletal implant that could connect to the nervous system in the limited space the team had to work with around the two bone attachment sites.
“Karin [the Danish patient] is now using somewhat the same neural resources to control the prosthesis as she did for her missing biological hand,” said Ortiz-Catalan. Karin then had her nerves and muscles repositioned by surgeons at Sahlgrenska University Hospital in Sweden, so they could then provide optimal motor control information to the prosthetic.
As well as day-to-day tasks involving load-bearing and controlled movements such as holding full cups and using zippers, it’s also significantly reduced the phantom pain (and subsequent pain medication), which she’s faced since her accident nearly 20 years ago. Ongoing pain is one of the reasons many amputees give up on traditional prosthetic limbs.
The futuristic limb, developed by Italian robotic hand prosthetics company Prensilia, features five grasps, one for each finger, and promises to provide 80 percent of daily movements. The results of the three-year study on Mia Hand integration signals a major step forward in the development of replacement limbs that can be used comfortably and functionally in daily life.
The research was published in the journal Science Robotics.
Source: Sant’Anna School of Advanced Studies, Pisa, Italy via www.newatlas.com.