Exploradio Origins: Making Robotic Limbs More Human
A research group at Case Western Reserve University, led by professor of biomedical engineering Dustin Tyler, works with neural implants in people who’ve lost limbs to restore not only motion with prosthetics, but also the sense of touch.
"We spent a lot of time understanding how our language, the electrical language, is translated into the human perception, predominantly in terms of sense of touch," Tyler said. "The first time we went in with our subject, we had no idea what was going to happen. So we first turned on the first stimulus pulses and he said, 'Wow, that's my thumb. That's the first time I felt my thumb since the accident.'"
Tyler’s implants have around 30 channels of information to work with, but normal human nerves can have hundreds. The trick is to figure out what language these nerves speak in order to convey normal sensation.
"While he felt his thumb, it was like, if your hand falls asleep and as you're waking up, you get that tingling feeling," Tyler said. "So we spent six months trying out different paradigms, sort of babbling in different languages, if you will. The next big moment was one day we went in and tried this new new pattern and, he said, 'I don’t feel tingling at all. It's just like I'm feeling my pulse.'"
Next, Tyler’s group wants to learn how our nerves encode more complex information, say the difference between sandpaper and silk, thus continuing to improve the missing limb's sense of touch in the brain, increasing the connection between human and device.