In a world first, surgeons and engineers have developed a new bionic hand that allows amputees to effortlessly control each finger as though it was their own body.
The first recipient of this technology is 52-year-old Tonney from Sweden who lost his arm from above the Elbow in a workshop accident.
Tonney quickly learnt how to master his new bionic arm, performing a number of tasks including using a screwdriver and pouring water into a glass.
Professor Max Ortiz Catalan, the lead researcher from the Centre for Bionics and Pain Research in Sweden, said:
“This is the first time a person with above-the-elbow amputation has been able to control each and every finger of a bionic hand.”
Until now, this technology has only been demonstrated in amputations below the elbow. Prof Ortiz Catalan explained that this is because “there are many muscles in the forearm that control the fingers.”
Traditionally the signals in an amputated limb from remaining nerves can be too faint to be picked up by the electrodes in an artificial limb. To rectify this, Ortiz Catalan and his team reconfigured the nerves in Tonney’s arm to new targets in the existing muscles to “amplify” the signals.
The next step involved using electrode sensors and a titanium bone implant to connect Tonney’s arm to the prosthetic. The titanium implant is more comfortable and stable compared to traditional artificial limb attachments that can cause discomfort and can be mechanically unstable.
Bionic arm uses machine-learning
The team utilised cutting edge machine-learning algorithms to translate the wearer’s intentions into movement of the prosthetic, enabling Tonney to move his bionic hand using his mind. Catalan explained:
“We combined surgical and engineering approaches to solve this problem… We basically re-distributed the motor neural signals to different types of muscle targets, all acting as biological amplifiers. Our patient uses the implanted electrodes to control his prosthetic hand in daily life because our unique neuromusculoskeletal interface that gives them that freedom.”
It is hoped that the advances in this field will help other amputees in the future. There are currently over 60 million people worldwide living with limb amputation.
According to the research team Tonney has now been living with his bionic hand for three years, and the device is currently in trials. After this phase is completed, it is hoped that surgeons and prosthetics specialists will be able to bring this technology to their patients.