2-Channel Electroencephalography Sensor Frontend for Portable Health Condition Monitoring Applications

This work presents a 2-channel electroencephalography (EEG) sensor frontend for portable health condition monitoring applications. The proposed scheme includes a compact and low power voltage mode EEG amplifier, successive approximation (SAR) analog-to-digital converter (ADC) with serial peripheral interface (SPI), where it can be easily installed in a safety helmet without giving much discomfort to the human subject. The EEG amplifier is implemented using CMOS 0.18 μm technology with 1.8 V supply. The measurement results per amplifier channel showed power consumption of 540 nW, input referred noise of 6.27 μV_rms within the bandwidth from 0.45 Hz to 250 Hz, and core area of 0.0198 mm². Furthermore, the EEG frontend operation is demonstrated with an actual EEG measurement setup, where the EEG signals are obtained from three different human subjects.