Prosthetics have evolved in a big way over the last century. Though they once merely emulated the appearance of the limbs they replaced, now functionality is key. But the next big goal for prosthetic limbs is to give their wearers the ability to feel touch once again, and one team of researchers just struck gold.
The latest advancement in prosthesis is a new fingertip created by researchers from the Scuola Superiore Sant'Anna and the Ecole Polytechnique Federale de Lausanne. While it doesn't have the functionality of a human finger, those wearing the device (a "neuromorphic real-time mechano-neuro-transduction" or MNT) can differentiate between certain surface textures -- smooth or rough, for instance. To use the device, researchers had to implant the fingertip and attach it to electrodes placed inside the body's nervous system. They also had a control group that received the fingertip but only had it attached to a nerve in their arm. According to their experiment, those with the nerve implant only differentiated correctly between different textures about 77% of the time whereas the former nervous system implant subject was able to do so 96% of times. That marks a stark difference.
But how could they know what the amputees were feeling? According to their study, the researchers used EEG activity to determine whether a physiological response to the surface texture was plausible or not by comparing it to the reactions from stimulation without the MNT.
There are many uses for a device like the MNT: of course, it can help those who have lost the ability to feel with their hands through amputation or a degenerative issue, but it also has implications for robotics and humanoid design. The ability to recreate a major component of the human system of sense is not a paltry accomplishment, and perhaps one day we'll be able to fully recreate other senses for those who have lost them.