A wearable UHF RFID-based EEG system

The wearable electroencephalogram (EEG) monitoring systems are the cornerstone of noninvasive brain-computer interfaces (BCI) and many medical applications, but state-of-the-art wearable systems are limited by weight, battery life and size. In this paper we present EEGWISP: am EEG monitoring system that is battery-free; is powered by a standard UHF RFID reader; and uses backscatter to transmit the data using a EPC Class 1 Gen2 protocol. Since EEGWISP does not need batteries it can be lightweight, miniature and maintenance free for users. We designed a low-power EEG acquisition circuit with 62.6 μA current consumption. For validation, EEG signals were shown by distinct appearance of 8-12 Hz oscillations (alpha waves) when wearer´s eyes are closed. EEGWISP can record EEG signals at 63 Hz sampling rate, at the distances up to 0.80 m and with 0.1 % data loss. With slight modifications, our system can be used for other biopotential signals such as ECG.