This thesis shows the reader the usable scientific measurment possibilities, focusing on the EEG-measurement, for the design and building of a BCI (Brain-computer interface). We focus on the EEG because its the most common way to harvest the signals of the brainwaves for the BCIs.
During the work, for a marketsaled BCI called EPOC Emotiv, I create several usable prototype electrodes, focusing on the dry electrode possibilities, because the Emotiv originally uses an electrode which requires a conductive liquid between them and the skin, so its harder to operate and use quickly. For this first I needed to creast the same connector to the Emotiv, so I used the mesurements of the original electrode and created it in a CAD (Computer Aided Design) software, which later was 3D-printed.
I present the softwares, whiches are able to extract the raw EEG data from the Emotic EPOC. Theese are written in the languages C++ and MATLAB. Both of them capable to extract the data and save it to a text-file, which later can be used for signal analysis and other postprocessing. I also present the created test-enviorment, it’s hardware, which was important for certain tests, like measuring Visual Evoked Potentials.
With the presented softwares, focusing on MATLAB, I show the result of my measurments on the prototype elctrodes, which includes measuring the contact quality, the spectrum of a signal admitted by the prototype, and also VEP measurements. I always compare theese results with the results of the original wet electrode of EPOC.