Researchers Make Prostheses Feel Real

Scientists in England are performing research toward making prostheses feel as if they are part of the wearer's body. In a study to be presented at the Royal Society's Summer Science Exhibition this week, the research team investigated the results of electrically stimulating volunteers' skin with transcutaneous electrical nerve stimulation (TENS) machines in order to 'trick' the brain into recognizing an artificial limb as its own. TENS machines are most commonly used for the relief of chronic pain, according to the BBC Health website.

The team hails from the Centre for Pain Research, Leeds Metropolitan University (Leeds Met), Leeds, England, and includes Mark Johnson PhD, PGCHE. Johnson reported to Medical News Today that they are attempting to stimulate nerve pathways associated with phantom pain using mild electrical currents that the brain may perceive as coming from the limb itself. He said, "Our experiments are designed to see whether we can make the sensation of TENS feel like it comes from a prosthetic hand in people with intact limbs. This will help us decide on the best design for a clinical trial in amputees." The research may allow prosthesis users to control their appliances with more finesse and sense of connection to the world.

"We are also trying to find out how useful TENS could be for phantom limb pain," Johnson added. "By adjusting the amplitude of TENS currents, we can activate the same nerves that we activate when we rub pain better. This stops messages about tissue damage getting to the brain and this reduces pain. This could help the 80 percent or so of amputees that experience pain in the limb that is now missing."

Describing the study's success, Johnson said, "We can create a very strong illusion that a rubber hand belongs to you, to the extent that you might try to move it as if its your own hand. It's even possible to make a table or a book feel like part of a body. It's just an illusion of course, but it shows us how the brain tries to make sense of the world from the information it receives, and how we might be able to use this to help people adjust more quickly to using an artificial limb." Visitors to the team's exhibit at the Summer Science Exhibition can try the experience themselves, using the research equipment to manipulate their brains into temporarily "adopting" a rubber hand of their own.