Brain-computer interface (BCI) technology aims to establish a direct link for transmitting information between the brain and external devices, offering a natural and rich control signal for prosthetic hands or functional electrical stimulators (FES) to re-animate paralyzed hands. This study focuses on an ECoG-based BCI system. ECoG measures brain activity using electrodes implanted on the surface of the brain. Each participant will undergo testing of the ECoG direct brain interface for up to 29 days. Participants will learn to control computer cursors, virtual reality environments, and assistive devices such as hand orthoses and functional electrical stimulators using neural activity recorded with the ECoG sensor.