The advance in semiconductor manufacturing technology has been promoting lower prices and higher performance for microprocessors and sensors. Herewith, it is possible to develop low cost bio-measurement equipment and these applications are expanding. Thus, we started to develop the compact electroencephalograph that is easier to use. The downsizing of the electroencephalograph was possible at a low cost by build-up type hardware structure consists of main module, amplifier module and filter function using software. The brain wave signal that is measured at the amplifier board is converted to data at main module. The processed data is sent to the PC or tablet via Wi-Fi. In this paper, we discuss the technology of the developed electroencephalograph and its applications.
