Scientists at Johns Hopkins have developed a new spinal stimulator that can help restore lower limb function to paralyzed patients. The tiny device can be non-invasively implanted through a syringe.
Spinal injuries interrupt the flow of electrical signals from the brain to the lower parts of the body, reducing mobility and in severe cases leading to total paralysis. Spinal stimulators are devices that can be surgically implanted into a patient’s spine to bypass the injury site and restore some mobility. Unfortunately, these are often bulky, require surgery, and have precision issues.
For the new study, the Johns Hopkins team developed a much smaller device that’s flexible and stretchable. It’s placed into a different site than other stimulators – the ventrolateral epidural surface, which is not only close to motor neurons for better precision, but it can just be injected into place with a regular syringe, no surgery required. Tests in paralyzed mice proved promising.
“Applying this new technology in a mouse model, we evoked leg motions using an electric current nearly two orders of magnitude lower than that used in traditional dorsal stimulation,” said Dinchang Lin, lead author of the study. “Our stimulator not only enabled a broader range of motions but also allowed us to program the electrode array's stimulation pattern, which resulted in more intricate and natural leg movements reminiscent of stepping, kicking, and waving.”
The team says the device could eventually help restore motor function in patients with spinal cord injuries or neurological diseases. Being less invasive should make the treatment more accessible and lower the cost, expanding the amount of people it could reach.
But of course, more development work needs to be done to get it ready for human use, including to test safety.
The research was published in the journal Nano Letters.
Source: Johns Hopkins University