MIT Technology Review reports that a brain computer interface chip control the patient’s actual arm with a system called functionalelectrical stimulation (FES). This will send signals to as many as 18 arm and hand muscles to allow the subject, who is paralyzed from the neck down, to perform tasks such as eating and nose-scratching.
“This will be the first time someone has hooked up a BCI to an FES device,” says Daniel Moran, a neuroscientist at Washington University at St. Louis who is not involved in the study. “They’re putting the whole system together.” The surgery may occur this or next year, according to Case Western researchers.
Beginning in mid 2008, with the agreement of Cyberkinetics, a new, fully academically-based IDE [Investigational device exemption (IDE)] application (for the “BrainGate2 Neural Interface System”) was developed to continue this important research. In May 2009, the FDA provided a new IDE for the BrainGate2 pilot clinical trial. [Caution: Investigational Device. Limited by Federal Law to Investigational Use.] The BrainGate2 pilot clinical trial is directed by faculty in the Department of Neurology at Massachusetts General Hospital, a teaching affiliate of Harvard Medical School; the research is performed in close scientific collaboration with Brown University’s Department of Neuroscience, School of Engineering, and Brown Institute for Brain Sciences, and the Rehabilitation Research and Development Service of the U.S. Department of Veteran’s Affairs at the Providence VA Medical Center. Additionally, in late 2011, Stanford University joined the BrainGate Research Team as a clinical site and is currently enrolling participants in the clinical trial. This interdisciplinary research team includes scientific partners from the Functional Electrical Stimulation Center at Case Western Reserve University and the Cleveland VA Medical Center. As was true of the decades of fundamental, preclinical research that provided the basis for the recent clinical studies, funding for BrainGate research is now entirely from federal and philanthropic sources.
Muscle activation technology has long been tested in paralyzed patients. Various patients can do things like press a button to activate muscles in their otherwise paralyzed legs to allow them to stand and even move about with a walker, helped along by legs that can stiffen and swing forward. If the patient does not have the use of his hands, activation of paralyzed muscles can be triggered by movements that a patient can control in his arm, cheek, or neck. The new effort will use the brain itself to send these signals.
At the heart of the new device is the brain implant—a small probe four millimeters on each side with 96 hair-like electrodes that penetrate 1.5 millimeters into a portion of the motor cortex that controls arm movements. The implant records the impulses of dozens of neurons corresponding to a patient’s intent to move.
In preparation for reconnecting real arm muscles, researchers have recently shown that the brain chip can control a virtual representation of those arm muscles. The ongoing clinical trial is known as BrainGate2.
Even if successful, the reanimated arm itself would still not be able to convey a sense of touch back to the wearer. In a separate set of experiments, researchers at Case Western are testing a system that provides a sense of touch thanks to sensors on a prosthetic hand wired to peripheral nerves in the patient’s arm (see “An Artificial Hand with Real Feelings”). In theory, such sensory feedback could be delivered directly to the brain, too.
Neuroscientists are also working on better brain implants. Current interfaces used in the project essentially collect someone’s intent to move something in a certain direction. Next-generation versions would actually collect more natural muscle-movement commands from the brain itself—a more challenging task but one that promises more realistic control. Another advance under development is a wireless interface between the skull connector and the system that reads and interprets the signals from the brain