Individuals with tetraplegia often have intact brain function but are unable to move due to injury or disease affecting the spinal cord, nerves or muscles. Advanced technology including functional electrical stimulators, robotic assistants and dexterous prosthetic limbs are being developed with the goal of restoring functions that are impaired due to paralysis of the upper limbs. However, these complex systems require high-dimensional control that cannot be achieved through currently available assistive devices due to limitations in functionality, ease of use and speed of use.
Brain-computer interface (BCI) technology is based on the finding that movement-related activity can be recorded from the motor cortex after paralysis or other impairment. This activity can be interpreted by a computer to provide an alternate “neural pathway” to control devices such as a robotic arm. Our laboratory is investigating the feasibility of using intracortical microelectrode arrays implanted in motor cortex for providing high degree of freedom control of a robotic arm. We are also testing the impact of somatosensory feedback, provided via intracortical microstimulation of the somatosensory cortex, on BCI control.
These studies are conducted under Investigational Device Exemptions from the Food and Drug Administration. Our first study participant demonstrated reliable control of a prosthetic arm with simultaneous, proportional control over 10 degrees of freedom: 3D translational velocity, 3D orientation velocity, and 4D hand-shape velocity. This led to significant improvement on clinical tests of upper limb function while using the device and enabled her to perform a wide variety of tasks.
We are working to discover how somatosensory feedback impacts performance, as well as how to continue to improve our neural decoding techniques to enable dexterous object manipulation.
Additional photos and videos can be found at www.upmc.com/bci