A mobile EEG system with dry electrodes

A new EEG recording device demonstrating an ultra-high input impedance is presented. Dry electrodes made of conductive rubber were employed for this study with careful shielding of the electrodes and cables. The device has a small form factor, so it is wearable, and has continuous Bluetooth connectivity. Tests were performed to assess features of the proposed device and to compare it with standard clinical devices. Simultaneous EEG recordings were measured from adjacent sites on the scalp using the new EEG device with dry electrodes and a reference EEG device with standard electrodes. The gain and bandwidth settings for the two devices were set similarly. Traditional closing eyes alpha-wave replacement and mu-rhythm were compared in both the time and frequency domains. Results from eight subjects show a high correlation coefficient (0.83 on average) between recordings of contiguous dry and standard electrodes. We conclude that the performance of the new device is comparable with standard EEG recording equipment, but offers a shorter set-up time, the possibility of long-term recording, and a wireless connection - all of which are advantages valuable in the field of brain computer interfaces and neurofeedback.