Pages Navigation Menu

SHOWFUN - Show & Fun & More!

Brain implant used to restore paralyzed man’s sense of touch

The human nervous system is a delicate thing. Damage it in the right place, and a person can lose the ability to control much of their bodies. Since the nervous system is largely based on the transmission of electrical impulses, scientists have long experimented with ways to replace the missing signals with artificial ones. In a new study, doctors have used a brain implant to return the sense of touch to a paralyzed man. The only difference is that now he feels with a robot hand.

The study is being conducted by researchers at the University of Pittsburgh and the University of Pittsburgh Medical Center. The subject of the study, Nathan Copeland, was paralyzed in a car accident 12 years ago. He lost all sensation from his arms down. But it’s not Copeland’s brain that’s the problem, it’s the nerves that transmit signals to and from the rest of his body. By placing electrodes inside Copeland’s brain, doctors have basically created a new path for the electrical impulses associated with the sense of touch.

It’s already possible in the laboratory to give people control of a robotic arm via a direct brain link. However, that’s just part of the puzzle. Without a sense of touch, using a robotic limb requires you to keep a close eye on it as you move and try to pick things up. With a standard-issue biological human arm, you can feel when your fingertips come in contact with something you want to pick up. Likewise, you know how much pressure you are exerting on it.

Modular Prosthetic Limb

To make this possible with a robot arm, the researchers started by monitoring Copeland’s brain via a non-invasive technique, called magnetoencephalography, as he was shown video of a hand touching things. The hypothesis was that the areas of the brain that showed activity spikes at that moment were probably the same ones that were supposed to light up when we touch something with our own hands. So, that’s where doctors implanted the electrodes in Copeland’s brain. When an electrical impulse is sent down the electrodes into his brain, Copeland experiences that sensation as touching something with his hand.

At that point, it was relatively simple to build pressure sensors into the Modular Prosthetic Limb and wire them up to Copeland’s brain. Well, maybe simple isn’t the right word, but doctors had what they needed to make it work. Copeland can now register touch sensations on all fingers individually without looking at the robotic limb.

For now, this is a great proof of concept. The limbs and monitoring machinery are still too bulky and expensive to integrate into people’s lives. It also requires brain surgery to implant electrodes. Perhaps in the future we’ll be able to bring the cost down and develop a less invasive way of stimulating the brain.

Leave a Comment

Captcha image