There are few things more human than the ability to feel. But for many amputees, the hope to be able to feel textures through prosthetic limbs has been difficult. Many recent advances involving prosthetics that operate with brain-machine interfaces, have been slowly giving this human gift back.
Just last week, a new bionic skin that has the acuteness of a fingertip was able to allow an amputee to feel rough and smooth textures, all in real-time.
The new artificial fingertip was developed by scientists at École polytechnique fédérale de Lausanne (EPFL) in Switzerland and Scuola Superiore Sant’Anna in Italy. It used a new technique that connected the device directly to the nerves in the upper arm of amputee Dennis Aabo Sørensen.
Not only was Sørensen able to accurately distinguish between rough and smooth surfaces, it did so through his own nervous system. “The stimulation felt almost like what I would feel with my hand,” Sørensen said.
Researchers were able to do this by connecting the artificial fingertip to nerves in the amputee’s arm. A machine then controlled device’s movement as it ‘felt’ a piece of textured plastic. As the fingertip was moving across the plastic, an electrical signal was generated by the sensors that was “translated into a series of electrical spikes” similar to the stimulation in a typical nervous system. This allowed his nerves to pick up the signal and send it to his brain.
As a control to their experiment, researches also tested their device against non-amputees, to see how it compared. The results showed that their device not only was able to keep up with fleshy fingers, it was far more accurate. The artificial fingertip was able to identify rough surfaces over 95 percent of the time, where “The non-amputees were able to distinguish roughness in textures 77 percent of the time.”
This innovation builds on the growing cannon of work turning the disable to into the super-abled.
For example, in February another mind-controlled limb at John Hopkins University tested a prosthetic that allowed a person to wiggle fingers individually on a bionic hand for the first time. This procedure wasn’t done with an amputee, but with a subject that already had 128 electrodes implanted in the brain surgically to help monitor epilepsy.
Because of the work that had already been done to map the brain, researchers were quickly able to take control of the arm.
Slightly more on the commercial side, BrainGate is creating a brain-machine-interface chip that can be inserted into the brain and used to control a robotic arm. So far they are able to perform routine tasks that would be unheard of even a few years ago, such as raising a glass to a users’ mouth.
Research into bionic limbs that and brain-controlled devices is accelerating, and now you can do more than read about it. The first ‘Cybathlon,’ a Swiss-hosted Olympics for bionic athletes and their robotic technologies, will be held in October and promises to not only enable participants, it will entertain audiences.
But the work on prosthetic limbs will have applications far beyond our fingertips. Calogero Oddo, who worked on the project, said that “It will also be translated to other applications such as artificial touch in robotics for surgery, rescue, and manufacturing.”