The Circuit Design of the Receiving Part of the Portable Electroencephalogram System
Subject Areas : Electronics Engineering
Marzieh
Moradi
1
(Department of Electrical and Computer Engineering, Islamic Azad University, Science and Research Branch, Tehran, Iran)
Mosoud
Dousti
2
(Department of Electrical and Computer Engineering, Islamic Azad University, Science and Research Branch, Tehran , Iran)
Keywords: low-noise design, EEG, chopper-stabilized technique,
Abstract :
In recent years, many electroencephalogram (EEG) devices have become portable and wireless. Given the requirements for mobility, EEG instruments need to be smaller, lighter, and power-efficient with reduced noise and offset. An EEG signal is very weak and its amplitude ranging is from 20 to 200 µV and its frequency ranges from 0.1 to 100 Hz. Besides, the skin-electrode interface creates a large DC offset voltage which can be in the order of ±300 mV. These two challenges can disturb the main signal and reduce the detection accuracy. At the input of amplification section of many EEG circuits, the chopping technique has been applied to convert DC input signals into AC signals. The main transconductance amplifier as EEG instrumentation amplifier (IA) in most of the previous works is the folded cascode amplifier. In this paper, we proposed a circuit which designed in 0.18 CMOS technology and its amplifier is a two-stage fully recycling chopper stabilized folded cascode amplifier that operates at low supply voltage and its input-referred noise is decreased by enhancing transconductance while it has a large slew rate, a high DC gain and an improved gain bandwidth. These features significantly decrease the noise and offset without a considerable increase in the power required by the circuit. In the post-layout simulation the amplifier achieves a midband gain of 60 dB and a -3dB bandwidth in the range of 0.1-210 Hz. the chip area with pads is 512×512 μm2. The adjustable LPF has a 100 Hz cut-off frequency.
[1] J. Feng, N. Yan and H. Min, "A low-power low-noise amplifier for EEG/ECG signal recording applications," IEEE International Conference on ASIC, 2011, pp. 145-148, doi:10.1109/ASICON.2011.6157143.
[2] N. Verma, A. Shoeb, J. Bohorquez, J. Dawson, J. Guttag and A. P. Chandrakasan, "A Micro-Power EEG Acquisition SoC With Integrated Feature Extraction Processor for a Chronic Seizure Detection System," in IEEE Journal of Solid-State Circuits, vol. 45, no. 4, pp. 804-816, April 2010, doi:10.1109/JSSC.2010.2042245.
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[4] N. Y. Sutri, J. O. Dennis, M. H. M. Khir and M. U. Mian, "Noise minimization techniques for modulator demodulator circuits used for chopper stabilization in CMOS-MEMS sensor applications," AFRICON, 2015, pp. 1-5, doi:10.1109/AFRCON.2015.7332005.
[5] R. R. Harrison and C. Charles, "A low-power low-noise CMOS amplifier for neural recording applications," in IEEE Journal of Solid-State Circuits, vol. 38, no. 6, pp. 958-965, June 2003, doi:10.1109/JSSC.2003.811979.
[6] M. Moradi, M. Dousti and P. Torkzadeh, "Designing a Low-Power LNA and Filter for Portable EEG Acquisition Applications," in IEEE Access, vol. 9, pp. 71968-71978, 2021, doi:10.1109/ACCESS.2021.3076160.
[7] X. Zhao, H. Fang, and J. Xu, “A transconductance enhanced recycling structure for folded cascode amplifier,” Analog Integr Circ Sig Process, vol.72, pp.259–263,2012, doi:10.1007/s10470-012-9843-6.
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[9] Z. Xiao, F. Huajun, X. Jun, “DC gain enhancement method for recycling folded cascode amplifier in deep submicron CMOS technology,” IEICE electronics express, vol. 8, pp. 1450-1454, Sep. 2011, doi:10.1587/elex.8.1450.
[10] A. Agnes, F. Maloberti and G. Martini, "Improved Chopper Stabilized Amplifier for Offset and 1/f Noise Cancellation," IEEE International Conference on Electronics, Circuits and Systems, 2006, pp. 529-532, doi: 10.1109/ICECS.2006.379842.
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[12] J. Yoo, L. Yan, D. El-Damak, M. A. B. Altaf, A. H. Shoeb and A. P. Chandrakasan, "An 8-Channel Scalable EEG Acquisition SoC With Patient-Specific Seizure Classification and Recording Processor," in IEEE Journal of Solid-State Circuits, vol. 48, no. 1, pp. 214-228, Jan. 2013, doi:10.1109/JSSC.2012.2221220.
[13] A. A. Alhammad, T.B. Nazzal1 and S. A. Mahmoud, “A CMOS EEG detection system with a configurable analog frontend architecture,” Analog Integr Circ Sig Process, vol. 89, pp. 151–176, Aug. 2016, doi:10.1007/s10470-016-0826-x.
[14] M. Nasseriana, A. Peiravia and F. Moradi, “A fully-integrated 16-channel EEG readout front-end for neural recording applications,” AEU - International Journal of Electronics and Communications, vol. 94, pp. 109-121, Sep. 2018, doi:10.1016/j.aeue.2018.06.045
[15] C. -J. Lee and J. -I. Song, "A Chopper Stabilized Current-Feedback Instrumentation Amplifier for EEG Acquisition Applications," in IEEE Access, vol. 7, pp. 11565-11569, 2019, doi:10.1109/ACCESS.2019.2892502.
[16] Z. Hoseini, M. Nazari, K. -S. Lee and H. Chung, "Current Feedback Instrumentation Amplifier With Built-In Differential Electrode Offset Cancellation Loop for ECG/EEG Sensing Frontend," in IEEE Transactions on Instrumentation and Measurement, vol. 70, pp. 1-11, 2021, Art no. 2001911, doi:10.1109/TIM.2020.3031205.
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[1] J. Feng, N. Yan and H. Min, "A low-power low-noise amplifier for EEG/ECG signal recording applications," IEEE International Conference on ASIC, 2011, pp. 145-148, doi:10.1109/ASICON.2011.6157143.
[2] N. Verma, A. Shoeb, J. Bohorquez, J. Dawson, J. Guttag and A. P. Chandrakasan, "A Micro-Power EEG Acquisition SoC With Integrated Feature Extraction Processor for a Chronic Seizure Detection System," in IEEE Journal of Solid-State Circuits, vol. 45, no. 4, pp. 804-816, April 2010, doi:10.1109/JSSC.2010.2042245.
[3] J. Xu, R. F. Yazicioglu, B. Grundlehner, P. Harpe, K. A. A. Makinwa and C. Van Hoof, "A 160 µW 8-Channel Active Electrode System for EEG Monitoring," in IEEE Transactions on Biomedical Circuits and Systems, vol. 5, no. 6, pp. 555-567, Dec. 2011, doi:10.1109/TBCAS.2011.2170985.
[4] N. Y. Sutri, J. O. Dennis, M. H. M. Khir and M. U. Mian, "Noise minimization techniques for modulator demodulator circuits used for chopper stabilization in CMOS-MEMS sensor applications," AFRICON, 2015, pp. 1-5, doi:10.1109/AFRCON.2015.7332005.
[5] R. R. Harrison and C. Charles, "A low-power low-noise CMOS amplifier for neural recording applications," in IEEE Journal of Solid-State Circuits, vol. 38, no. 6, pp. 958-965, June 2003, doi:10.1109/JSSC.2003.811979.
[6] M. Moradi, M. Dousti and P. Torkzadeh, "Designing a Low-Power LNA and Filter for Portable EEG Acquisition Applications," in IEEE Access, vol. 9, pp. 71968-71978, 2021, doi:10.1109/ACCESS.2021.3076160.
[7] X. Zhao, H. Fang, and J. Xu, “A transconductance enhanced recycling structure for folded cascode amplifier,” Analog Integr Circ Sig Process, vol.72, pp.259–263,2012, doi:10.1007/s10470-012-9843-6.
[8] M. Akbari, S. Biabanifard, S. Asadi, and M. C. E. Yagoub, “Design and analysis of DC gain and transconductance boosted recycling folded cascode OTA,” AEU—International Journal of Electronics and Communications, vol.68, no.11, 1047–1052, 2014, doi:10.1016/j.aeue.2014.05.007.
[9] Z. Xiao, F. Huajun, X. Jun, “DC gain enhancement method for recycling folded cascode amplifier in deep submicron CMOS technology,” IEICE electronics express, vol. 8, pp. 1450-1454, Sep. 2011, doi:10.1587/elex.8.1450.
[10] A. Agnes, F. Maloberti and G. Martini, "Improved Chopper Stabilized Amplifier for Offset and 1/f Noise Cancellation," IEEE International Conference on Electronics, Circuits and Systems, 2006, pp. 529-532, doi: 10.1109/ICECS.2006.379842.
[11] N. Verma, A. Shoeb, J. Bohorquez, J. Dawson, J. Guttag and A. P. Chandrakasan, "A Micro-Power EEG Acquisition SoC With Integrated Feature Extraction Processor for a Chronic Seizure Detection System," in IEEE Journal of Solid-State Circuits, vol. 45, no. 4, pp. 804-816, April 2010, doi:10.1109/JSSC.2010.2042245.
[12] J. Yoo, L. Yan, D. El-Damak, M. A. B. Altaf, A. H. Shoeb and A. P. Chandrakasan, "An 8-Channel Scalable EEG Acquisition SoC With Patient-Specific Seizure Classification and Recording Processor," in IEEE Journal of Solid-State Circuits, vol. 48, no. 1, pp. 214-228, Jan. 2013, doi:10.1109/JSSC.2012.2221220.
[13] A. A. Alhammad, T.B. Nazzal1 and S. A. Mahmoud, “A CMOS EEG detection system with a configurable analog frontend architecture,” Analog Integr Circ Sig Process, vol. 89, pp. 151–176, Aug. 2016, doi:10.1007/s10470-016-0826-x.
[14] M. Nasseriana, A. Peiravia and F. Moradi, “A fully-integrated 16-channel EEG readout front-end for neural recording applications,” AEU - International Journal of Electronics and Communications, vol. 94, pp. 109-121, Sep. 2018, doi:10.1016/j.aeue.2018.06.045
[15] C. -J. Lee and J. -I. Song, "A Chopper Stabilized Current-Feedback Instrumentation Amplifier for EEG Acquisition Applications," in IEEE Access, vol. 7, pp. 11565-11569, 2019, doi:10.1109/ACCESS.2019.2892502.
[16] Z. Hoseini, M. Nazari, K. -S. Lee and H. Chung, "Current Feedback Instrumentation Amplifier With Built-In Differential Electrode Offset Cancellation Loop for ECG/EEG Sensing Frontend," in IEEE Transactions on Instrumentation and Measurement, vol. 70, pp. 1-11, 2021, Art no. 2001911, doi:10.1109/TIM.2020.3031205.