New Tech Tricks Brain Into Thinking Bionic Limbs Are Lighter
As technology advances, size usually decreases too. The first video cameras were huge, bulky devices that felt like you were carrying a shot on your shoulder. Nowadays, with a smartphone that is thinner than a deck of cards and weighs about as much or as little, you can get great recording quality.
However, in some cases there is a limit to how much you can shrink a piece of technology and still have it useful. A prosthetic leg for an amputee can be scaled down to some extent, but it must remain a certain size in order to function as a prosthetic leg. Likewise, a weight reduction in the prosthesis can be achieved by using lighter materials, although weight reductions are ultimately limited by the size restrictions.
How do you make such a prosthesis more comfortable for the people who have to use it every day? According to scientists at ETH Zurich, a university in Switzerland, the answer is simple (at least in theory): They use clever “nerve hacking” technology to trick the wearer’s brain into believing the prosthesis is lighter than it actually is.
“Millions of amputees don’t use prostheses because they [find] they are too heavy when in reality they are lighter than [a biological] leg, ”said Stanisa Raspopovic, professor at the Institute for Health Sciences and Technology at ETH Zurich, to Digital Trends. “For this reason, reducing weight would improve the user experience and reduce the task of the prosthesis.”
A fascinating proof-of-concept demonstration
In a demonstration of the proof concept, the researchers recently implanted electrodes that can deliver electrical impulses to the remaining leg nerves of amputees. This made the participants feel 25% lighter than the prosthesis they were wearing.
About 36% of participants said it made them feel safer, and more than 50% said the prosthesis felt more like an actual part of their body. What was impressive was that they were also able to carry out other tasks – such as the apparently unrelated spelling of words while walking – more efficiently, as they were neither mentally nor physically stressed by the prosthetic leg.
While this is currently only the experimental phase of the project, Raspopovic said that commercialization is definitely planned for the future. “[This] would be a small implantable device under the skin that stimulates nerves triggered by external wearable sensors, ”he said. “We work [toward that goal]We hope to plan a massive clinical trial with a spin-off, SensArs, in 2022 [the] next five years. “
An article describing the work was recently published in the journal Current Biology.