  Brain-Computer Interface(BCI) systems support communication through direct
measures of neural activity without muscle activity. Brain-Computer Interface
systems need to be validated in long-term studies of real-world use by people
with severe disabilities, and effective and viable models for their widespread
dissemination must be implemented. Finally, the day-to-day and moment-to-moment
reliability of BCI performance must be improved so that approaches the
reliability of natural muscle-based function. This review discusses the
structure and functions of BCI systems, clarifies terminology integration and
progress, and opportunities in the field are also identified and explicated
based on the current availability of invasive recording technologies used for
BCI systems.
