Could tiny computers help paralyzed people walk?

SEATTLE -- The Paul G. Allen Family Foundation is funding a project by University of Washington researchers that could enable paralyzed people to move by implanting tiny computers under the skin.

UW researchers are attempting to restore movement in individuals who have been paralyzed by a spinal injury or stroke by recording the brain activity of a person's intention to move and translating that into a stimulation which causes the desired motion.

Allen's foundation has contributed $1.5 million to fund the project known as the "Brain-Computer-Spinal-Interface."

"Mr. Allen believes in supporting creative researchers willing to take risks," said Kathy Richmond, senior program officer of the Science & Technology Program at the foundation. "This research has very immediate benefits for patients and will answer basic questions about neurological signaling that can lay the foundation for other technological innovations."

The Brain-Computer-Spinal-Interface project is a collaboration between biophysicists Dr. Chet Moritz and Dr. Adrienne Fairhall and electrical engineer Dr. Joshua Smith.

Moritz explained many paralyzed people have a fully functional brain and muscles as well as a damaged spinal cord - which connects the mental desire to move with actual muscle movement. He and his colleagues hope to bridge that gap and send stimulation directly to nerves, muscles or the spinal cord below the injured area to restore a person's control of movement.

"It's essentially a small area that's damaged," Moritz said. "We're creating an electronic device to bypass that damaged area of the central nervous system."

Allen's grant money will be used in part to develop tiny computers to implant under the skin and wirelessly translate brain signals to the spinal cord.

Past research has focused on using electronic currents to directly stimulate muscles, but Moritz said this tends to cause rapid fatigue. For example, pinching the thumb and forefinger together required stimulating eight different muscles.

"It's easier to instigate from the spinal cord," Moritz said. "We've shown by stimulating within the spinal cord we're able to invoke more complex movements."

Those movements could include walking. Other research groups are able to coordinate stepping motions using as few as two electrodes controlling each leg.

While walking might seem like the most crucial need for a paralyzed person, Moritz said he is actually most focused on restoring arm and hand movement, which is the greatest request from surveys of individuals with paralysis affecting both the arms and legs.

"Even a simple task like reaching and grasping would dramatically improve their quality of life," Moritz said. "It means less dependence on a caregiver."

Whether this project is successful or not, Moritz said the lessons he and his team learn - about how the brain codes information, learns and adapts - could be applied to other areas of research.

If it is successful, Moritz cautions that it will still be several years before the technology can be tested on humans and even longer before it could possibly become an available treatment option for the public.

"We're very excited but it's important to remember this is just the beginning."