Here's how we might fix spinal injuries in the future: with an implant that reconnects our body with the rest of our nervous system.
Researchers at the Swiss Federal Institute of Technology, in Lausanne, have developed the e-Dura—a tiny skinlike device that attaches directly to damaged spinal cords. By sending out small electrical pulses, it stimulates the cord as if it were receiving signals from the brain, thus allowing movement.
"The purpose of the neuro-prosthesis is to excite the neurons that are on the spinal cord below the site of the injury and activate them, just like if they were receiving information from the brain," says Stéphanie Lacour, a professor at the institute.
Lacour describes the e-Dura like a rubber band with fine strips of metal in it (tracks and electrodes) for passing small charge of electricity through. Simultaneously, the device also has a micro-fluidic channel that delivers a drug. In tests with paralyzed rats, Lacour's team, working with another lab, helped the animals walk again (albeit upright and in harnesses). "The combination of two systems enables the full restoration of the activity," Lacour says.
The e-Dura is named after "dura mater"—the protective skin around the spinal cord. To insert the device, the researchers made a small incision in the back of the rats, slipping it next to the cord itself, then wiring it out. Eventually, once the e-Dura is developed for humans, it'll probably be controlled remotely, or have a battery like a pacemaker.
It'll be a while before e-Dura is installed in humans. But the project has answered important questions about attaching something inanimate to something as sensitive as a spinal cord. You would worry about chafing, etc., but Lacour says the material—a simple silicone polymer—is sympathetic, malleable, and very thin. The material can be made a single micron thick.
The next step for Lacour, who's on the materials and engineering side of the project, is to look to connect the device with the actual brain. At the moment, the spinal cord can be stimulated artificially, but not from the signals of the brain. Lacour also wants to see how the implant could be used in other parts of the nervous system that've been damaged, like the brain itself.