A pump made of two plastic syringes and a pushing block powered by a stepper motor, one of our Muscle SpikerShields and a 3D-printed base — that’s all that Kiley Branan, a high school senior from Indiana, needed to put together a prototype of a finger that you can open and close by flexing your arm.
If it sounds like a prosthetic device, it’s because that was what Kiley had originally intended it to be. But as she was figuring out the mechanics, the project evolved into a physical therapy tool that can’t replace a limb but can help people who were born without one or have had an amputation to learn kinesthetic and fine motor skills. It is customizable, easy to learn, and best of all — it’s very cheap. With high-tech bionic limbs often being prohibitively expensive, people should at least get a chance to adjust to them at a next-to-nothing cost.
So how exactly does it work? When you’re about to “tell” your muscles to move your limb, your brain sends electrical signals called action potentials to the spinal cord, which then passes on the message to your muscles via motor neurons. But what happens if a person is missing the limb? The message is still being transmitted. What’s missing, apart from the recipient limb, is something to “intercept” the message, gauge and interpret it.
That’s where Kiley’s device comes in. “It detects the nerve signals in the arm when they tell the muscle to move, and then tells the coded computer to push the syringes forward or backward so that they can move the finger. So the device helps detect something that already exists in a person who doesn’t have a finger,” the 18-year-old tells us over Zoom. The device would be helpful on two levels. On the one hand, it would allow for better fine-tuning and customization of the prosthetic limb before it gets made. On the other, it would prepare the person and improve their fine motor skills before they receive their first prosthetic. In a nutshell, Kiley says, it would “make the transition from living without a limb to using a prosthetic as seamless as possible.”(more…)