Neuroscientists from the University of Chicago (UChicago) have developed a computer model that can simulate the response of nerves in the hand to any pattern of touch stimulation on the skin. The tool reconstructs the response of more than 12,500 nerve fibers with millisecond precision, taking into account the mechanics of the skin as it presses against and moves across objects. In addition to its impact on the basic understanding of how these sensations work, the model is also a foundation for restoring touch in bionic prosthetic hands for people with amputations.
Population responses for different tactile experiences.
Image courtesy of the Proceedings of the National Academy of Sciences.
To achieve realistic feelings of touch, neural engineers try to reproduce the natural patterns of nerve activity generated when we manipulate objects. The computer model provides engineers with the nerve output generated by a given stimulus, which can then be recreated in a prosthesis by electrically stimulating the nerve through an interface implanted in the body.
The software will allow scientists to see how entire populations of nerve fibers respond when we interact with objects. The model will allow scientists to better understand how the nerve responds to touch, and ca be used to build realistic sensations into bionic hands for amputees.
“Almost everything we know about how the nerve responds to stimulation on the skin of the hand is built into this model,” said Sliman Bensmaia, PhD, associate professor of organismal biology and anatomy at UChicago, and principal investigator for the new research. “Finally, you can see how all these nerve fibers work together to give rise to touch.”
Details of the model were published in the June issue of the Proceedings of the National Academy of Sciences. The study builds upon years of research by Bensmaia’s team about how the nervous system and brain perceive the sense of touch.
Bensmaia and his team validated the output of the model against data from a wide variety of experiments conducted by other research teams, and show that it matches their output with millisecond precision. The software will be available as a free download, so other engineers can begin using it in their own work.
“Using a model to reproduce a biological system precisely is challenging, and we have been working on this simulation for a very long time. But the final product, I think, is worth it,” Bensmaia said. “It’s a tool that will yield insights that were previously unattainable.”
Editor’s note: This story was adapted from materials provided by the University of Chicago Medical Center.