By stimulating existing nerves, a new form of prosthetics brings feeling back to those who’ve lost legs.
image via youtube screen capture
The field of prosthetics has taken a huge step forward with the recent unveiling of a new form of artificial appendage that not only affords wearers an increased level of mobility, but also enables them to actually feel stimuli from the prosthetic itself.
Created by Hubert Egger, a Professor at Austria's University of Linz, the experimental limb is outfitted with an array of six sensors able to pick up and translate physical interactions into electronic impulses. Those impulses are then channeled into an amputee’s nerve-endings, allowing the wearer to “feel”—and their brain to process—whatever the prosthetic, in this case a leg, encounters.
To accomplish this feat, explains MedicalXPress, the wearer’s still-functioning nerve endings must be “rewired” from their amputational stump and brought closer to the skin’s surface, where they can be connected with “stimulators” in the artificial limb’s attachment cradle. According to Wolfgang Rangger, an amputee who's been testing Professor Egger's limb for the past six months, the effect is profound. Speaking with Agence France-Presse, Rangger is enthusiastic for his new leg:
“It's like a second lease of life, like being reborn. It feels like I have a foot again. I no longer slip on ice and I can tell whether I walk on gravel, concrete, grass or sand. I can even feel small stones.”
Egger is already known by many in the prosthetic community for his 2010 work on mechanized prosthetic arms which can be controlled using a patient’s brainwaves.
This video, posted to a youtube account registered in Professor Egger’s name, highlights some of the complex mechanical considerations which go into the creation of an advanced prosthetic leg.
As IFLScience points out, Professor Egger’s new breakthrough not only lets amputees feel the ground beneath their feet once more, it also helps disrupt what’s known as “Phantom Limb Pain”—a condition believed to arise when an amputee’s brain struggles with the loss of input from an appendage it thinks should still be sending nerve signals. By providing its own stimuli, Egger’s prosthetic fulfills the brain’s search for input, thereby correcting the neurological confusion, and negating the resulting pain.
Professor Egger claims the medical risks involved in a bio-technical leap like this are surprisingly minimal. He believes that, “the only risk is that the nerves don't reconnect properly and the feelings fail to return.” In other words, even if the limb’s capacity to “feel” ends up a no-go, users will still have a perfectly good prosthetic leg with which they can regain mobility, and continue living their lives.
The “feeling” limb currently costs upwards of $11,000 dollars, making it an attractive, but tremendously expensive, option for many amputees. However, bolstered by the prosthetic’s success during testing, Professor Egger is reportedly on the hunt for corporate partners to help bring that price down.