Date: 20/06/2012

700µW, 8-channel active-electrode-based EEG monitoring system from imec

At the recently concluded VLSI circuits symposium (June 12-15, Honolulu, USA), imec presented a complete 700µW 8-channel active-electrode (AE)-based EEG monitoring system. The system, developed in collaboration with Panasonic is said to deliver high quality EEG signals and facilitates ambulatory use and patient comfort.

Imec explains: The complete low-power 8-channel EEG system consists of a set of AEs and a back-end (BE) analog signal processor. It is capable of continuously, while concurrent recording 8 channel EEG signals and electrode-tissue contact impedance (ETI) of the biopotential electrodes. This simultaneous recording enables remote assessment of electrode status during EEG recording. The EEG channels of the system consume less than 87µW (including ETI). The AEs have a gain that relaxes the noise specifications of the BE and a high input impedance (1.2GO at 10Hz) that enables recording from dry electrode. A complete EEG channel, consisting of two AEs and the BE, has high common-mode CMRR (>84dB), and a low noise (1.75µVrms, 0.5-100Hz). These characteristics are essential to extract high quality EEG-signals: µV-range low-frequency signals under a large amount of common-mode (CM) interference.

Imec says EEG acquisition system does not require the use of commercial active components (e.g., bulky instrumentation amplifiers, ADCs etc) in the signal path and delivers a complete solution for digital interfacing. The system is suitable for ambulatory EEG monitoring. Compared to current EEG monitoring systems, ambulatory monitoring increases the patient’s autonomy and comfort. The system is also applicable for sports devices, entertainment, comfort monitoring, and other health and lifestyle products and services.