Bionic Fingertip lets Amputee Feel Texture for First Time

bionic prosthetic fingertip amputee epfl touch
The bionic fingertip connects to surgically implanted electrodes, allowing the wearer to distinguish between rough and smooth textures. Alain Herzog/ EPFL

An amputee has been able to feel textures for the first time using an artificial fingertip connected to nerves in his arm.

Dennis Aabo Sorensen, a Dane who severely wounded his left arm 11 years ago in a fireworks accident, was able to feel rough and smooth textures using a bionic fingertip that sent signals in real time to electrodes surgically implanted above his stump.

The technology, developed by researchers at  École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland and Scuola Superiore Sant’Anna (SSSA) in Italy, is expected to accelerate the development of touch-enabled prosthetics.

“Hopefully we will be able to transfer it to clinical practice in five to 10 years,” Silvestro Micera, professor at EPFL and SSSA and head of the research team, tells Newsweek.

The signals transmitted to Sorensen’s stump mimicked the language of the nervous system to provide accurate feedback on the texture the fingertip was touching. In the tests, conducted at the EPFL in Switzerland, the amputee was able to distinguish between rough and smooth surfaces 96 percent of the time.

“The stimulation felt almost like what I would feel with my hand,” Sorensen said. “I still feel my missing hand, it is always clenched in a fist. I felt the texture sensations at the tip of the index finger of my phantom hand.”

It is not the first time Sorensen has been the subject of experiments involving bionic prosthetics. In 2014, Sorensen’s implants were connected to a sensory-enhanced prosthetic hand capable of recognizing shape and softness.TEXT

bionic touch prosthetic fingertip epfl How an amputee can feel rough and smooth textures with a bionic fingertip. EPFL

There are limitations to the technology, Micera warns, with sensations like hot and cold difficult to distinguish between due to the small size of the nerves providing this type of information. The researcher suggests artificial temperature sensors could be embedded into prosthetics that could inform the wearer whether an object is hot or cold. He says: “The information coming from temperature sensors in the hand prosthesis could be used for local robot closed-loop, which could directly control the prosthesis like a reflex.”

The research is set to be published today in the journal eLife.