An EEG-NIRS Multimodal SoC for Accurate Anesthesia Depth Monitoring

In surgical operation environments, anesthesia enables doctors to safe and accurate medical process with minimized movement and pain of patients. In general anesthesia, non-invasive and reliable monitoring of anesthesia depth is required because it is directly related to patient’s life. However, the current anesthesia depth monitoring approach, bispectral index (BIS), uses only electroencephalography (EEG) from the frontal lobe, and it shows critical limitations in the monitoring of anesthesia depth such as signal distortion due to electrocautery, electromyography (EMG) and dried gel, and false response to the special types of anesthetic drugs. In this paper, a multimodal head-patch system that simultaneously measures EEG and near-infrared spectroscopy (NIRS) on the frontal lobe is proposed. For EEG monitoring, mixed-mode dc-servo loop is proposed to cancel out the ±300-mV electrode-dc offset for dried gel condition with 3.59 noise-efficiency factor. To compensate the electromagnetic noises (EMG and electrocautery) in the system level, NIRS signal is measured. Logarithmic transimpedance amplifier (TIA) and closed-loop controlled (CLC) NIRS current driver are proposed. Logarithmic TIA can reject ambient light up to 10 nA to achieve a 60-dB dynamic range. According to the comparator output, CLC NIRS driver duty cycle can be adjusted from 0.625 m to 50 ms adaptively. The 16-mm2 system-on-chip is fabricated in 65-nm CMOS. It dissipates 25.2-mW peak power. With the combined signals, it can show the clinically important transition from the awake to deep state, but BIS cannot detect the transition in a clinical trial.

[1]  Kazuyoshi Hirota,et al.  Special cases: ketamine, nitrous oxide and xenon. , 2006, Best practice & research. Clinical anaesthesiology.

[2]  Peter S. Sebel,et al.  Development and Clinical Application of Electroencephalographic Bispectrum Monitoring , 2000, Anesthesiology.

[3]  Leonardo Teixeira Domingues Duarte,et al.  When the bispectral index (bis) can give false results. , 2009, Revista brasileira de anestesiologia.

[4]  Anantha Chandrakasan,et al.  An 8-Channel Scalable EEG Acquisition SoC With Patient-Specific Seizure Classification and Recording Processor , 2013, IEEE Journal of Solid-State Circuits.

[5]  T. Voepel-Lewis,et al.  Awareness in children: a secondary analysis of five cohort studies , 2011, Anaesthesia.

[6]  R. Nunes,et al.  Bispectral index and other processed parameters of electroencephalogram: an update. , 2012, Revista brasileira de anestesiologia.

[7]  Jan M. Rabaey,et al.  A Minimally Invasive 64-Channel Wireless μECoG Implant , 2015, IEEE Journal of Solid-State Circuits.

[8]  D. Haas,et al.  Management of complications during moderate and deep sedation: respiratory and cardiovascular considerations. , 2007, Anesthesia progress.

[9]  Hyunki Kim,et al.  A Wearable EEG-HEG-HRV Multimodal System With Simultaneous Monitoring of tES for Mental Health Management , 2015, IEEE Transactions on Biomedical Circuits and Systems.

[10]  Ming Gu,et al.  Design of a Programmable Gain, Temperature Compensated Current-Input Current-Output CMOS Logarithmic Amplifier , 2014, IEEE Transactions on Biomedical Circuits and Systems.

[11]  Chen Zhang,et al.  A 16-Channel Patient-Specific Seizure Onset and Termination Detection SoC With Impedance-Adaptive Transcranial Electrical Stimulator , 2015, IEEE Journal of Solid-State Circuits.

[12]  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.

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

[14]  Medical Advisory Secretariat Bispectral index monitor: an evidence-based analysis. , 2004, Ontario health technology assessment series.

[15]  Hoi-Jun Yoo,et al.  27.2 A 25.2mW EEG-NIRS multimodal SoC for accurate anesthesia depth monitoring , 2017, 2017 IEEE International Solid-State Circuits Conference (ISSCC).

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