Publication

EEG recording technology creates the opportunity to sense and discover potential
fluctuation in the human brain. Quantitative analysis based on various EEG
sensor nodes provide vital information on the patient’s mental and physiological
status. However, conventional multi-channel work requires wire connections and
thus suffers from huge environmental interference, which makes it difficult to be
wearable and durable for daily EEG monitoring. Some work tried to solve the
problem of common mode interference from power line coupling by using a
common mode charging pump (CMCP) technique, which cancels out a certain
amount of common mode voltage. However, the charging speed of the capacitor
makes it unsuitable when coupled common mode potential changes over time
and environment. Some work proposed a floating power system with an onchip
frequency-controlled LDO, while it requires all channels tied together to
average out the common mode potential and forced a power plane to be shared
by all of them, which works for implantable neural recording system instead of a
widespread distributed EEG recording system. Moreover, a conventional EEG
recording system requires a separate reference electrode, which introduces more
connection wires and extra interferences. For the active electrode, which
removes the input connection wires to reduce common mode interference, the
potential difference between circuit ground and human body is another essential
issue, a driven-right leg circuit is used in leads to extra wire/interference and
stability issue. Work in proposed in-ear EEG AFE with BCC transmission,
however, concurrent signal recording/BCC transmission is not reported.

Researcher/Author: Tao Tang, Long Yan, Jeong Hoan Park, Han Wu, Lian Zhang, Ho Yin Benjamin Lee, Jerald Yoo

2020 IEEE International Solid-State Circuits Conference, 978-1-7281-3205-1; https://ieeexplore.ieee.org/document/9063054