Implant could bring wireless exoskeleton control to paralyzed people

A brain implant the size of a paper-clip might one day help paralyzed people regain the ability to use their arms and legs via a wireless connection that will transmit their thoughts to an exoskeleton.

It's not the first technology to allow paralyzed people to operate mechanicallimbs with signals from their brain,but it has the potential to revolutionize the field because it's minimallyinvasive and totally wireless.

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It's made possible because of a matchstick-sized implant called astentrode,crafted from nitinol, an alloy that iscommonly used inbrassiere underwiresand eyeglass frames,according toa study publishedin the journalNature Biotechnology.

"It's really a new method for getting brain data out of the brain without performing brain surgery,"ThomasOxley, a neurologist at the University of Melbourne who designed the device, told CBC News.

"Part of the reason that brain-machine interfaces have not been successful to this point is because they get rejected by the body, and the reason they get rejected is because they all require direct implantation into the brain. And to do that you have to take off the skull you have to perform a craniotomy."

The new technology developed by a team scientists from theUniversity of Melbourne's medicine, science, veterinary science and engineering faculties is implanted in a blood vessel next to the motor cortex, the region of the cerebral cortex involved in the planning, control and execution of voluntary movements. The stentrode eliminates the need for complex surgery.

The researchers were inspired by advancements in cardiac medicine that allow pacemakers to be inserted via blood vessels, rather than through open-heart surgery.

"We had the same idea. You go up through the arteries,or through the blood vessels, up into the brain, choose the part of the brain you want, and then deposit the electrodes inside the blood vessels right next to the brain, but never goactually into the brain," Oxleysaid.

Once the implant issafely nestled near the motor cortex, it will theoretically be able to pick up signals from the brain and transmit them to an exoskeleton allowing a patient to move their limbs with the power of their own thoughts.

The stentrodehas already proven safe and painless in tests on sheep. The researchershope to begin human trials in 2017 on a select group ofpeople who have been left paralyzedby spinal cord injuries.

However, it won't be quick or easy, Oxey said.

"The trial is going toinvolve a learningperiod where the patients have to learn how to activate the device in their brain,"Oxley said. "It's kind of like learning how toplay a new sport or learning how toplay the piano it takes time."

The stentrodecould have implicationsfor a wide range of neurological disorders if it works, he said.

For example, an implant in people with epilepsy could record brain activity and potentiallypredict an oncoming seizure, he said.

Or it could provide a less-invasive alternative to deep brain stimulation, a process wherein doctorsimplant electrodes deep inside the brain to treat a range of disorders including Parkinson's disease, severe depression and obsessive-compulsive disorder.

If tests prove successful, the researchers hope to bring the device to market by 2022.