Active Electrodes for Wearable EEG Acquisition: Review and Electronics Design Methodology

Active electrodes (AEs), i.e., electrodes with built-in readout circuitry, are increasingly being implemented in wearable healthcare and lifestyle applications due to AEs' robustness to environmental interference. An AE locally amplifies and buffers μV-level EEG signals before driving any cabling. The low output impedance of an AE mitigates cable motion artifacts, thus enabling the use of high-impedance dry electrodes for greater user comfort. However, developing a wearable EEG system, with medical grade signal quality on noise, electrode offset tolerance, common-mode rejection ratio, input impedance, and power dissipation, remains a challenging task. This paper reviews state-of-the-art bio-amplifier architectures and low-power analog circuits design techniques intended for wearable EEG acquisition, with a special focus on an AE system interfaced with dry electrodes.

[1]  Stefan Debener,et al.  Mobile EEG: towards brain activity monitoring during natural action and cognition. , 2014, International journal of psychophysiology : official journal of the International Organization of Psychophysiology.

[2]  Christian Birk,et al.  A 60V capacitive gain 27nV/√Hz 137dB CMRR PGA with ±10V inputs , 2012, 2012 IEEE International Solid-State Circuits Conference.

[3]  Jan M. Rabaey,et al.  A 0.013 ${\hbox {mm}}^{2}$, 5 $\mu\hbox{W}$ , DC-Coupled Neural Signal Acquisition IC With 0.5 V Supply , 2012, IEEE Journal of Solid-State Circuits.

[4]  Johan H. Huijsing,et al.  Indirect Current Feedback Instrumentation Amplifier with a Common Mode Input Range That Includes the Negative Rail , 1992, ESSCIRC '92: Eighteenth European Solid-State Circuits conference.

[5]  Jyh-Yeong Chang,et al.  Novel Dry Polymer Foam Electrodes for Long-Term EEG Measurement , 2011, IEEE Transactions on Biomedical Engineering.

[6]  J. Millán,et al.  Single trial analysis of slow cortical potentials: a study on anticipation related potentials , 2013, Journal of neural engineering.

[7]  Chris Van Hoof,et al.  Comb-shaped polymer-based Dry electrodes for EEG/ECG measurements with high user comfort , 2013, 2013 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC).

[8]  J. H. Huijsing,et al.  Microelectronic skin electrode , 1990 .

[9]  Heinz Jäckel,et al.  A pseudodifferential amplifier for bioelectric events with DC-offset compensation using two-wired amplifying electrodes , 2006, IEEE Transactions on Biomedical Engineering.

[10]  A.-T. Avestruz,et al.  A 2 $\mu\hbox{W}$ 100 nV/rtHz Chopper-Stabilized Instrumentation Amplifier for Chronic Measurement of Neural Field Potentials , 2007, IEEE Journal of Solid-State Circuits.

[11]  Sang-Hoon Lee,et al.  A capacitive, biocompatible and adhesive electrode for long-term and cap-free monitoring of EEG signals. , 2013, Journal of neural engineering.

[12]  João M. Nóbrega,et al.  Development of a quasi-dry electrode for EEG recording , 2013 .

[13]  Refet Firat Yazicioglu,et al.  A 15-Channel Digital Active Electrode System for Multi-Parameter Biopotential Measurement , 2015, IEEE Journal of Solid-State Circuits.

[14]  Karim Abdelhalim,et al.  The 128-Channel Fully Differential Digital Integrated Neural Recording and Stimulation Interface , 2010, IEEE Transactions on Biomedical Circuits and Systems.

[15]  G. Comi,et al.  IFCN standards for digital recording of clinical EEG. International Federation of Clinical Neurophysiology. , 1998, Electroencephalography and clinical neurophysiology.

[16]  T Schmidt,et al.  New Dry Electrodes with Comparable Performance as Standard Electrodes , 2013, Biomedizinische Technik. Biomedical engineering.

[17]  Yong Lian,et al.  A 1V 22µW 32-channel implantable EEG recording IC , 2010, 2010 IEEE International Solid-State Circuits Conference - (ISSCC).

[18]  Kofi A. A. Makinwa,et al.  A 1.8 $\mu$ W 60 nV$/\surd$ Hz Capacitively-Coupled Chopper Instrumentation Amplifier in 65 nm CMOS for Wireless Sensor Nodes , 2011, IEEE Journal of Solid-State Circuits.

[19]  G. Cauwenberghs,et al.  Micropower non-contact EEG electrode with active common-mode noise suppression and input capacitance cancellation , 2009, 2009 Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[20]  Carmen C. Y. Poon,et al.  Wearable Medical Systems for p-Health , 2008, IEEE Reviews in Biomedical Engineering.

[21]  C. A. Grimbergen,et al.  HIGH QUALITY RECORDING OF BIOELECTRIC EVENTS . I : INTERFERENCE REDUCTION , THEORY AND PRACTICE , 2009 .

[22]  Anantha Chandrakasan,et al.  A sub-μW 36nV/√Hz chopper amplifier for sensors using a noise-efficient inverter-based 0.2V-supply input stage , 2016, 2016 IEEE International Solid-State Circuits Conference (ISSCC).

[23]  Shuang Song,et al.  A Low-Voltage Chopper-Stabilized Amplifier for Fetal ECG Monitoring With a 1.41 Power Efficiency Factor , 2015, IEEE Transactions on Biomedical Circuits and Systems.

[24]  Shyamal Patel,et al.  A review of wearable sensors and systems with application in rehabilitation , 2012, Journal of NeuroEngineering and Rehabilitation.

[25]  Refet Firat Yazicioglu,et al.  A 60 $\mu$W 60 nV/$\surd$Hz Readout Front-End for Portable Biopotential Acquisition Systems , 2007, IEEE Journal of Solid-State Circuits.

[26]  Enrique Mario Spinelli,et al.  A Multichannel EEG Acquisition Scheme Based on Single Ended Amplifiers and Digital DRL , 2012, IEEE Transactions on Biomedical Circuits and Systems.

[27]  P. Tallgren,et al.  Evaluation of commercially available electrodes and gels for recording of slow EEG potentials , 2005, Clinical Neurophysiology.

[28]  C A Grimbergen,et al.  High-quality recording of bioelectric events , 1991, Medical and Biological Engineering and Computing.

[29]  Daniel Sánchez Morillo,et al.  Dry EEG Electrodes , 2014, Sensors.

[30]  Kofi A. A. Makinwa,et al.  Dynamic Offset Cancellation Techniques for Operational Amplifiers , 2013 .

[31]  Paolo Fiorini,et al.  Human++: autonomous wireless sensors for body area networks , 2005, Proceedings of the IEEE 2005 Custom Integrated Circuits Conference, 2005..

[32]  Thomas Burger,et al.  A DC-connectable multi-channel biomedical data acquisition ASIC with mains frequency cancellation , 2013, 2013 Proceedings of the ESSCIRC (ESSCIRC).

[33]  Refet Firat Yazicioglu,et al.  24.7 A 60nV/√Hz 15-channel digital active electrode system for portable biopotential signal acquisition , 2014, 2014 IEEE International Solid-State Circuits Conference Digest of Technical Papers (ISSCC).

[34]  Refet Firat Yazicioglu,et al.  A $160~\mu {\rm W}$ 8-Channel Active Electrode System for EEG Monitoring , 2011, IEEE Transactions on Biomedical Circuits and Systems.

[35]  L. Duartea,et al.  Development of a quasi-dry electrode for EEG recording , 2013 .

[36]  Refet Firat Yazicioglu,et al.  Measurement and Analysis of Current Noise in Chopper Amplifiers , 2013, IEEE Journal of Solid-State Circuits.

[37]  Jan M. Rabaey,et al.  A 0.013mm2 5μW DC-coupled neural signal acquisition IC with 0.5V supply , 2011, 2011 IEEE International Solid-State Circuits Conference.

[38]  Hyunki Kim,et al.  21.9 A wearable EEG-HEG-HRV multimodal system with real-time tES monitoring for mental health management , 2015, 2015 IEEE International Solid-State Circuits Conference - (ISSCC) Digest of Technical Papers.

[39]  Gabriel Curio,et al.  Brain-computer communication and slow cortical potentials , 2004, IEEE Transactions on Biomedical Engineering.

[40]  A. C. MettingVanRijn,et al.  Low-cost active electrode improves the resolution in biopotential recordings , 1996, Proceedings of 18th Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[41]  Yong Lian,et al.  A 1-V 450-nW Fully Integrated Programmable Biomedical Sensor Interface Chip , 2009, IEEE Journal of Solid-State Circuits.

[42]  Refet Firat Yazicioglu,et al.  A 200 $\mu$ W Eight-Channel EEG Acquisition ASIC for Ambulatory EEG Systems , 2008, IEEE Journal of Solid-State Circuits.

[43]  Hariprasad Chandrakumar,et al.  5.5 A 2µW 40mVpp linear-input-range chopper- stabilized bio-signal amplifier with boosted input impedance of 300MΩ and electrode-offset filtering , 2016, 2016 IEEE International Solid-State Circuits Conference (ISSCC).

[44]  Roberto Guerrieri,et al.  Active Electrode IC for EEG and Electrical Impedance Tomography With Continuous Monitoring of Contact Impedance , 2015, IEEE Transactions on Biomedical Circuits and Systems.

[45]  Anantha Chandrakasan,et al.  A Biomedical Sensor Interface With a sinc Filter and Interference Cancellation , 2011, IEEE Journal of Solid-State Circuits.

[46]  John G. Webster,et al.  Driven-right-leg circuit design , 1983, IEEE Transactions on Biomedical Engineering.

[47]  A. Baba,et al.  Time Based Measurement of the Impedance of the Skin-Electrode Interface for Dry Electrode ECG Recording , 2007, 2007 29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[48]  Michel Verleysen,et al.  A CMOS/SOI Single-input PWM Discriminator for Low-voltage Body-implanted Applications , 2002, VLSI Design.

[49]  Johan H. Huijsing,et al.  Indirect Current Feedback Instrumentation Amplifier with a Common Mode Input Range That Includes the Negative Rail , 1992 .

[50]  K. Makinwa,et al.  A Current-Feedback Instrumentation Amplifier With 5 $\mu{\hbox{V}}$ Offset for Bidirectional High-Side Current-Sensing , 2008, IEEE Journal of Solid-State Circuits.

[51]  Refet Firat Yazicioglu,et al.  18.3 A multi-parameter signal-acquisition SoC for connected personal health applications , 2014, 2014 IEEE International Solid-State Circuits Conference Digest of Technical Papers (ISSCC).

[52]  Fan Zhang,et al.  Design of Ultra-Low Power Biopotential Amplifiers for Biosignal Acquisition Applications , 2012, IEEE Transactions on Biomedical Circuits and Systems.

[53]  Kofi A. A. Makinwa,et al.  A Current-Feedback Instrumentation Amplifier with 5μV Offset for Bidirectional High-Side Current-Sensing , 2008, 2008 IEEE International Solid-State Circuits Conference - Digest of Technical Papers.

[54]  Refet Firat Yazicioglu,et al.  A 160μW 8-channel active electrode system for EEG monitoring , 2011, 2011 IEEE International Solid-State Circuits Conference.

[55]  J Haueisen,et al.  Novel Multipin Electrode Cap System for Dry Electroencephalography , 2015, Brain Topography.

[56]  Gert Cauwenberghs,et al.  Ultra-High Input Impedance, Low Noise Integrated Amplifier for Noncontact Biopotential Sensing , 2011, IEEE Journal on Emerging and Selected Topics in Circuits and Systems.

[57]  Refet Firat Yazicioglu,et al.  A Wearable 8-Channel Active-Electrode EEG/ETI Acquisition System for Body Area Networks , 2014, IEEE Journal of Solid-State Circuits.

[58]  C. Grozea,et al.  Bristle-sensors—low-cost flexible passive dry EEG electrodes for neurofeedback and BCI applications , 2011, Journal of neural engineering.

[59]  R. R. Harrison,et al.  A low-power low-noise CMOS amplifier for neural recording applications , 2003, IEEE J. Solid State Circuits.

[60]  Tzyy-Ping Jung,et al.  Dry-Contact and Noncontact Biopotential Electrodes: Methodological Review , 2010, IEEE Reviews in Biomedical Engineering.

[61]  Kofi Makinwa,et al.  A 2.1 μW area-efficient capacitively-coupled chopper instrumentation amplifier for ECG applications in 65 nm CMOS , 2010, 2010 IEEE Asian Solid-State Circuits Conference.

[62]  Enzo Pasquale Scilingo,et al.  Affective computing in virtual reality: emotion recognition from brain and heartbeat dynamics using wearable sensors , 2018, Scientific Reports.

[63]  Leonardo G. Cohen,et al.  To jump or not to jump: The Bereitschaftspotential required to jump into 192-meter abyss , 2018, bioRxiv.

[64]  Gabor C. Temes,et al.  Circuit techniques for reducing the effects of op-amp imperfections: autozeroing, correlated double sampling, and chopper stabilization , 1996, Proc. IEEE.

[65]  Refet Firat Yazicioglu,et al.  An Implantable 455-Active-Electrode 52-Channel CMOS Neural Probe , 2014, IEEE Journal of Solid-State Circuits.

[66]  Refet Firat Yazicioglu,et al.  A 160 $\mu{\rm A}$ Biopotential Acquisition IC With Fully Integrated IA and Motion Artifact Suppression , 2012, IEEE Transactions on Biomedical Circuits and Systems.

[67]  Heinz Jäckel,et al.  Low-Noise Two-Wired Buffer Electrodes for Bioelectric Amplifiers , 2007, IEEE Transactions on Biomedical Engineering.

[68]  Naveen Verma,et al.  A Micro-Power EEG Acquisition SoC With Integrated Feature Extraction Processor for a Chronic Seizure Detection System , 2010, IEEE Journal of Solid-State Circuits.