MULTI-FREQUENCY ENCODING METHOD FOR A BRAIN-COMPUTER INTERFACE BASED ON STEADY STATE VISUALLY EVOKED POTENTIAL.

摘要

The present disclosure is related to a multi-frequency encoding method applicable to the visual stimulation signals used in the BCI based on SSVEP; which are in correspondence with the frequencies used in the visual stimulus. But the number of available frequencies caused by the SSVEP are using a single stimulation frequency; therefore limited to a few of them, and by matching each frequency to a command in the brain-computer communication, this will result in a very limited communication. This method will increase the number of commands in the brain-computer communication, representing them in a binary form by using multiple frequencies that are mixed in the same stimulation signal, where each one of these combinations represents a binary code. The combinations must contain from one to three bits in state one, so that the resulting signal from this encoding, do not contain more than three simultaneous stimulation frequencies so that the amplitude of the SSVEP peaks could be appreciab le. Using nine frequencies, there will be a code with 512 combinations, and from which 129 of them, could be used since they meet the stated condition, representing 129 communication commands, making it broader.