Researchers at the University of Pittsburgh School of Medicine and UPMC describe in PLoS ONE how an electrode array sitting on top of the brain enabled a 30-year-old paralyzed man to control the movement of a character on a computer screen in three dimensions with just his thoughts. It also enabled him to move a robot arm to touch a friend’s hand for the first time in the seven years since he was injured in a motorcycle accident.
With brain-computer interface (BCI) technology, the thoughts of Tim Hemmes, who sustained a spinal cord injury that left him unable to move his body below the shoulders, were interpreted by computer algorithms and translated into intended movement of a computer cursor and, later, a robot arm, explained lead investigator Wei Wang, Ph.D., assistant professor, Department of Physical Medicine and Rehabilitation, Pitt School of Medicine.
“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, reflecting on a memorable scene from September 2011 that was re-told in stories around the world. “It’s very important that we continue this effort to fulfill the promise we saw that day.”
Six weeks before the implantation surgery, the team conducted functional magnetic resonance imaging (fMRI) of Mr. Hemmes’ brain while he watched videos of arm movement. They used that information to place a postage stamp-size electrocortigraphy (ECoG) grid of 28 recording electrodes on the surface of the brain region that fMRI showed controlled right arm and hand movement. Wires from the device were tunneled under the skin of his neck to emerge from his chest where they could be connected to computer cables as necessary.
For 12 days at his home and nine days in the research lab, Mr. Hemmes began the testing protocol by watching a virtual arm move, which triggered neural signals that were sensed by the electrodes. Distinct signal patterns for particular observed movements were used to guide the up and down motion of a ball on a computer screen. Soon after mastering movement of the ball in two dimensions, namely up/down and right/left, he was able to also move it in/out with accuracy on a 3-dimensional display.
“During the learning process, the computer helped Tim hit his target smoothly by restricting how far off course the ball could wander,” Dr. 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.”
The robot arm was developed by Johns Hopkins University’s Applied Physics Laboratory. Currently, Jan Scheuermann, of Whitehall, Pa., is testing another BCI technology at Pitt/UPMC.
For more information about participating in the trials, call research coordinator Debbie Harrington at 412-383-1355.
Co-authors of the paper include Jennifer L. Collinger, Ph.D., Alan D. Degenhart, Andrew B. Schwartz, Ph.D., Douglas J. Weber, Ph.D., Brian Wodlinger, Ph.D., Ramana K. Vinjamuri, Ph.D., and Robin C. Ashmore, Ph.D., all of the University of Pittsburgh; Elizabeth C. Tyler-Kabara, M.D., Ph.D., and Michael L. Boninger, M.D., of the University of Pittsburgh and UPMC; Daniel W. Moran, Ph.D., of Washington University in St. Louis; and John W. Kelly, of Carnegie Mellon University.
The study was funded by the National Institute of Neurological Disorders and Stroke, part of the National Institutes of Health, the University of Pittsburgh’s Clinical and Translational Science Institute, and UPMC.
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About the University of Pittsburgh School of Medicine
As one of the nation’s leading academic centers for biomedical research, the University of Pittsburgh School of Medicine integrates advanced technology with basic science across a broad range of disciplines in a continuous quest to harness the power of new knowledge and improve the human condition. Driven mainly by the School of Medicine and its affiliates, Pitt has ranked among the top 10 recipients of funding from the National Institutes of Health since 1998. In rankings recently released by the National Science Foundation, Pitt ranked fifth among all American universities in total federal science and engineering research and development support.
Likewise, the School of Medicine is equally committed to advancing the quality and strength of its medical and graduate education programs, for which it is recognized as an innovative leader, and to training highly skilled, compassionate clinicians and creative scientists well-equipped to engage in world-class research. The School of Medicine is the academic partner of UPMC, which has collaborated with the University to raise the standard of medical excellence in Pittsburgh and to position health care as a driving force behind the region’s economy. For more information about the School of Medicine, see www.medschool.pitt.edu.
About the UPMC Rehabilitation Institute
The UPMC Rehabilitation Institute combines clinical care and research to help patients regain independence and enhance their quality of life following debilitating illnesses or injuries such as stroke, spinal cord injury and traumatic brain injury. The Institute’s academic partner, the Department of Physical Medicine and Rehabilitation at the University of Pittsburgh School of Medicine, is ranked No. 2 in research funding from the National Institutes of Health (NIH) among physical medicine and rehabilitation programs across the country.
The largest rehabilitation provider in western Pennsylvania, the Institute serves as the hub of a UPMC network of more than 70 rehabilitation facilities. In June 2009, the Institute opened a newly renovated, 76-bed center at UPMC Mercy, offering an unparalleled expansion of specialized services for the most traumatic and complicated injuries of the brain or spinal cord, as well as for strokes. This transition of services to UPMC Mercy makes the Institute the region’s only rehabilitation facility with an on-site Level 1 Trauma Center. For more information about the Institute, visit UPMC.com/RehabInstitute.