Tuesday, June 14, 2011

Machines, Monkeys and New Hope for Treating Paralysis

Research being conducted by Dr. Miguel Nicolelis from Duke University has uncovered a new method for capturing brain function by recording the way neurons work together as a symphony, rather than the activity of single neurons. This research is paving the way for new ways of treating paralysis.

In the field of neuroscience for the last 100 years, the belief has been particular areas of the brain are responsible for certain functions. However, research in the last decade has shown neurons all over the brain are contributing, albeit in different ways, to generate a particular behavior.

"This new field of brain research is taking off and changing what we thought we knew," said Dr. Miguel Nicolelis during the Beyond Boundaries lecture at Florida Hospital Orlando on June 8.



Taking this new information about how the brain operates he, along with his team, began to question if they could create therapies to restore function in those with spinal cord injuries or other debilitating conditions by building a brain machine interface.

A brain machine interface works by implanting small electrodes just beneath the scalp, which are capable of recording the electrical signals in the brain responsible for various motor behaviors. The signals are then sent to the machine so the message can be decoded, translated into digital commands and sent to a robotic arm, a robotic leg or virtual body to create movement.

To test their brain machine interface Nicolelis’ team experimented with primates. Now, his star monkey, Aurora, is known all over the world because she was one of the first primates to actually enact its voluntary motor will just by thinking.

Aurora learned to play a video game by controlling the joystick with her own arm and was rewarded every time she “scored” by getting a drop of fruit juice. While she was learning to play the game, the team recorded her brain activity so computers could learn to reproduce her arm movements in a robotic device stored in another room. After a few weeks the team removed the joystick and Aurora quickly came to the realization that to play the game and get her fruit juice, she didn't need to move her body at all. She just had to imagine the movements and the robotic arm would move and control the computer cursor so she could keep playing and winning her fruit juice.

Going a step further they decided to test how far the signal could reach. Using a 12-pound, 32-inch monkey named Idoya made a 200-pound, 5-foot humanoid robot walk on a treadmill using only her brain activity. Her walking pattern and brain signals were collected in North Carolina, fed into the computer and transmitted over a high-speed Internet link to a robot in Kyoto, Japan.

According to the New York Times, the robot, called CB for Computational Brain, has the same range of motion as a human. It can dance, squat, point and “feel” the ground with sensors embedded in its feet, and it will not fall over when shoved.

As Idoya’s brain signals streamed into CB’s actuators, her job was to make the robot walk steadily via her own brain activity. She could see the back of CB’s legs on an enormous movie screen in front of her treadmill and received treats if she could make the robot’s joints move in synch with her own leg movements.

The trick came when the researchers stopped Idoya's treadmill. What would happen? She focused on the movie screen and CB's legs continued to move. And, Idoya got her treats.



Yet, to make this effective for humans, it became important to prove that not only could the brain machine interface receive signals from the brain, but could also send them back so conceivably one could recognize and feel the movement happening. Nicolelis used the example of a soccer player who doesn’t have to see where the ball is at all times to know it is there because it is literally an extension of him.

Reminiscent of the blockbuster movie, Avatar, the team created an avatar monkey in a virtual world and discovered the real monkey, using the brain machine interface, was able to control the avatar monkey and recognize and feel different textures in the virtual world.  

The revelations from his work with primates have led to funding opportunities for The Walk Again Project. The main goal of the project currently is to debut the brain machine interface technology at the 2014 World Cup in Brazil by having a Brazilian teenager who is paralyzed walk out with the Brazilian soccer team with the help of an exoskeleton.


Walk Again is a multinational collaborative effort to free paralyzed patients from the confines of their physical bodies through breakthroughs in neuroscience. Led by the Duke Center for Neuroengineering, Walk Again is developing a high performance brain-controlled prosthetic device that enables patients to finally leave the wheelchair behind.

For more information, please visit www.walkagainproject.org


  


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