A recent study by the University of Pittsburgh School of Medicine explains how an electrode array placed at the top of the brain can enable movement of computers and a robotic hand with thought alone. The technology allowed him to give his friend a high five for the first time in seven years.
Tim Hemmes is a 30-year-old man who was paralyzed from a motorcycle accident that took place nearly seven years ago. The spinal cord injury that resulted from the accident left him with tetraplegia and unable to control his body below the shoulders.
Six weeks prior to the implantation of the brain electrodes, the research team conducted functional magnetic resonance imaging (fMRI) of Hemmes’s brain while he observed videos that showed arm movement. With the data gathered, the team placed a postage stamp-sized electrocortigraphy (ECoG) grid consisting of 28 electrodes on the surface of the brain. The electrodes were placed in the same area of the brain that the fMRI showed as active when the right hand moved.
Over the course of 21 days, nine of which were spent in the research lab, Hemmes watched a virtual arm move. This triggered signals that were read by the electrodes. Over time, the movement was mastered, and the 3-D display of a ball was being controlled by his thoughts alone. The wires connecting the implant to the computer were placed under the skin of the neck and exited the body from the chest area.
“During the learning process, the computer helped Tim hit his target smoothly by restricting how far off course the ball could wander,” Dr. Wei Wang said. “We gradually took off the ‘training wheels,’ as we called it, and he was soon doing the tasks by himself with 100 percent brain control.”
“When Tim reached out to high-five me with the robotic arm, we knew this technology had the potential to help people who cannot move their own arms achieve greater independence,” said Dr. Wang. “It’s very important that we continue this effort to fulfill the promise we saw that day.”
The study gives hope that in time, technology will be available to help more people gain the ability to manage day-to-day tasks by thought alone. The study was funded by the National Institute of Neurological Disorders and Stroke. The robotic arm was developed by John Hopkins University’s Applied Physics Laboratory.
To read more about the strides UPMC is making with their brain-controlled robotic arm, see our previous story: Quadriplegic Feeds Herself Using Brain-Controlled Robotic Arm. To watch the touching video of Tim Hemmes and his first “high five” with his girlfriend, see the video below … and grab a tissue!