Brain Implant that Could Reanimate Paralyzed Limbs Secures $16M in Funding

The National Science Foundation recently awarded the Center for Sensorimotor Neural Engineering at the University of Washington a $16 million grant for research that will hopefully lead to implantable tech that promotes brain plasticity and the reanimation of paralyzed limbs.

"When Christopher Reeve sustained a spinal cord injury due to a fall from his horse, his brain circuits were still intact and able to form the intention to move, but unfortunately the injury prevented that intention from being conveyed to the spinal cord," said CSNE director and UW professor of computer science and engineering Rajesh Rao. "Our implantable devices aim to bridge such lost connections by decoding brain signals and stimulating the appropriate part of the spinal cord to enable the person to move again."

The devices that are being worked on at the Center are known as bi-directional brain-computer interfaces. The idea is these devices would be implanted in the brain where they would record and decode electrical signals that are formed when a person forms an intention to do something, such as walk or pick up a cup. The state of the brain when these intentions are formed are then encoded in a wireless signal which is sent to another part of the nervous system, thereby circumventing the damaged regions of the nervous system and restoring movement in the paralyzed limb.

The Center for Sensorimotor Neural Engineering is a collaborative project between the University of Washington, Massachusetts Institute of Technology, and San Diego State University which was founded in 2011 with an $18.5 million grant from the NSF. In addition to the bi-directional brain implant devices, the researchers at the Center have also been working on improving existing implantable tech, such as the deep brain stimulators that are used to treat Parkinson's disease.

Usually, these devices work by bombarding the brain with electrical signals at a physician prescribed frequency to help treat tremors and other physiological effects resulting from Parkinson's. The downside of this is that the brain is being pinged with electrical pulses even when it isn't necessary (such as when a person is resting), which can lead to unwanted side effects and more surgeries to replace the device's battery. The researchers at the Center are trying to improve on this design by using closed-loop implants which only send electrical signals to the brain as needed.

The news that the NSF was re-upping the funding for the Center was a relief for the researchers working on these devices, but now that the funding is secure, they have a number of pressing technical and ethical questions to answer as they prepare their devices for clinical trials. In the first place, the team must develop complex algorithms that are capable of correctly interpreting brain signals and delivering the signals to the appropriate place in the body, so that one doesn't form an intention to move their right hand while the device sends a signal that causes the left hand to move.

Furthermore, the team must figure out how create a device that can be implanted in the brain without being rejected. According to Rao, brain tissue tends to envelop implants in scar tissue, which would hinder their ability to properly function. Moreover, Rao said that the team is looking into ways to power the implants wirelessly, removing the need for surgeries to replace the device's batteries.

A portion of the grant will also be used to research the ethics of such brain implants, which Rao told the Seattle Times could have implications for "fundamental issues of identity."

Despite the hard work ahead of them, Rao and his team remain optimistic about the future of their implantable devices. He hopes to see proof-of-concept demonstrations in humans within five years, which will be the first step in getting the devices approved for widespread use by the FDA.

"It's a very targeted rehabilitation approach, as opposed to drugs or physical therapy," Rao told the Seattle Times. "It would radically alter the way we might help people for stroke or spinal-cord injury."