Bionic technology allows amputees to feel warmth in missing hand

To feel the the form of the orange is one thing; to feel it hot or cold another. Keystone / Matt Rourke

Swiss and Italian researchers have developed a technology to enable people with amputated hands to feel temperature differences – via a “phantom hand” effect.

The discovery came as something of a surprise, the Swiss Federal Institute of Technology Lausanne (EPFL) said on ThursdayExternal link.

When the researchers placed thermal electrodes on the arm stumps of study participants, the expectation was that they would report feeling warmth or cold on the stump itself. However, 17 of the 27 participants felt temperature variations on the missing hand – a discovery which the scientists, also from the Sant’Anna School of Advanced Studies in Pisa, called a “thermal phantom sensation”.

+ Read more: prosthetic hand can sense objects’ form and position

Not only could the patients feel whether an object was hot or cold – they could also tell if they were touching copper, plastic or glass.

Which position could be assigned to which part of the phantom hand was also unique for each patient.

No implants

The technology, which has been tested for more than two years, does not need to be implanted. It can be worn on the skin and combined with a regular prosthetic.

Silvestro Micera, a co-leader of the study, told Reuters that they now wanted to test the device on a larger scale before combining it with other technologies to improve tactile sensations in amputees.

Not only were the researchers enthusiastic about this, but also the study participants. “It was the first time in 20 years that I could actually feel the warmth of another person with my phantom hand. It felt like someone was touching my missing hand,” said participant Roberto Renda. “It’s like I have a connection to someone.”

The findings were published on Thursday in the journal ScienceExternal link.