Imec, Holst Centre and Panasonic have developed a new prototype of a wireless EEG (electroencephalogram) headset. The system combines ease-of-use with ultra-low power electronics. Continuous impedance monitoring and the use of active electrodes increases the quality of EEG signal recording compared to former versions of the system. The data are transmitted in real-time to a receiver located up to 10m from the system. The realization of this prototype is a next step towards reliable high-quality wearable EEG monitoring systems.
The headset has a high common-mode rejection ratio (>92 dB), low noise (<6 µVpp, 0.5-100Hz), DC offset tolerance of +/- 900mV and is AC coupled with configurable cut-off frequency. Sensitivity and dynamic range are configurable through a programmable gain stage (default 1.5mVpp and 366nV, respectively). It is capable of continuously recording 8 channel EEG signals while concurrently recording electrode-tissue contact impedance (ETI). This simultaneous ETI recording enables continuous, remote assessment of electrode contact status during EEG recording. The autonomy of the system ranges from 22 hours (8 channels of EEG with ETI) to 70 hours (1 channel of EEG only).