A System on Chip based electroencephalogram acquisition system
Current Brain computer interfaces (BCI) are usually implemented by a biopotential acquisition board and a computer (PC), where the signal processing is performed. Since these have demonstrated their potential to improve the quality of life of people with reduced mobility and speech losses, it is time to migrate to smaller devices, eliminating the PC from the scheme. The strict real time processing requirements of BCI justify the use of a System on Chip (SoC) for this propose. This work presents an electroencephalogram (EEG) acquisition system based on a low-cost DE10-nano SoC provided by Altera. The complete system is described and EEG records of an alpha rhythm, corresponding to a user during a period of relaxation, are shown. Through off-line processing of the signal, its frequency spectrum is obtained, which has a maximum amplitude at 12.8 Hz, characteristic for a signal of this type. The validation of the acquisition system constitutes a solid starting point for the development of a fully functional BCI in the future, as well as other applications with more demanding time constraints.