In a First, a Prosthetic Limb Can Sense Temperature Like a Living Hand

The advance may help users feel a greater sense of human connection through touch

Brian Handwerk

Science Correspondent

February 9, 2024

Amputees’ hopes to experience the feeling of human touch using their prosthetics are becoming closer to reality. Now, new technology is allowing them to feel temperature—even in limbs that are no longer part of their bodies.

For the first time, a functional artificial limb has been fitted with fingertip sensors that allow an ordinary prosthetic hand to sense and respond to temperature just as a living hand does. The device provides a realistic sense of hot and cold in the missing “phantom” hand by delivering thermal information to nerve areas on the amputee’s residual limb that the brain believes are still connected to the missing hand. The MiniTouch, described in a study published Friday in Med, was created with affordable off-the-shelf electronics, requires no surgery and can be fitted to existing commercial prosthetic hands in a matter of hours.

“With these new technologies I can understand better what I am touching,” says Fabrizio Fidati, a 57-year-old man who had his arm amputated below the elbow 37 years ago and recently tested the device. “Certainly, my priority would be to use it in a kitchen to cook!”

The ability to sense hot and cold temperatures is an important advance for the functionality of prosthetic limbs, but it’s also much more. Temperature adds a human element to touch. Feeling warmth creates a stronger sense of embodiment, the belief that a prosthesis isn’t just an artificial tool but a part of a person’s body.

“We have a colleague who says touch without temperature is like vision without color,” says senior author Solaiman Shokur, a neuroengineer at the Swiss Federal Institute of Technology in Lausanne. Shokur notes researchers are improving prosthetics’ abilities to feel textures. They are also homing in on proprioception, the brain’s ability to know where a body part is and how it’s moving. Temperature, he notes, is an important third sensation. “The next step would be to put them all together, and that’s where you have the full palate of sensations” he says.

More:
https://www.smithsonianmag.com/science-nature/in-a-first-a-prosthetic-limb-can-sense-temperature-like-a-living-hand-180983765/