This Thought-Controlled Robotic Arm Possesses The Sense Of Touch

This is probably as good as it gets with prosthetic limbs and hands. Latest developments in neuroprosthetics allow the implantation of electrodes that mimic not just the movement but also enhanced control and sense of touch. These two neuroprosthesis instill the ability to recognize sensation as well as redesign precise motor control. The prosthetic hand designed by Tyler and his colleagues from Case Western Reserve University establishes its contact with electrodes under the human skin. They implanted a couple of electrodes close to the nerve bundles of two men who lost their hands due to accidents. Interestingly, both men were able to carry out daily activities for a couple of years with no issues whatsoever.

Prothesis
Image courtesy: Russell Lee/The subject holding a cherry tomato

Tyler and his colleagues were able to enhance the sensory perception of the two men by transmitting electrical pulses via their prosthetic hands. The intensity was varied which excited various neurons bearing various patterns. This is the kind of behavior one notices when touching and gripping something. The patients noticed and reported that they actually felt as if they were grabbing objects with the natural extension of the body. According to Tyler, this helps to reactivate the parts of the brain which produce the sense of touch. This input is usually lost once the hand is lost.

Prothetic limb
Courtesy Image: Russell Lee/Holding, not crushing a grape

Such sensations were reactivated along various parts of the hand. One of the participants was blindfolded upon which he reported that he felt a cotton ball grazing the rear of his prosthesis. The other participant claimed he felt like water was running down the hand. This was a result of transmission of electric signals from a computer right into the nerves in the brain and the arms. They were able to precisely carry out the basic activities such as holding cherry tomato, grabbing grapes and squeezing out toothpaste.