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Wu CY, Huang CW, Chen YW, Lai CK, Hung CC, Ker MD. Design of CMOS Analog Front-End Local-Field Potential Chopper Amplifier With Stimulation Artifact Tolerance for Real-Time Closed-Loop Deep Brain Stimulation SoC Applications. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2024; 18:539-551. [PMID: 38198255 DOI: 10.1109/tbcas.2024.3352414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
A CMOS analog front-end (AFE) local-field potential (LFP) chopper amplifier with stimulation artifact tolerance, improved right-leg driven (RLD) circuit, and improved auxiliary path is proposed. In the proposed CMOS AFE LFP chopper amplifier, common-mode artifact voltage (CMAV) and differential-mode artifact voltage (DMAV) removal using the analog template removal method are proposed to achieve good signal linearity during stimulation. An improved auxiliary path is employed to boost the input impedance and allow the negative stimulation artifact voltage passing through. The common-mode noise is suppressed by the improved RLD circuit. The chip is implemented in 0.18- μm CMOS technology and the total chip area is 5.46-mm2. With the improved auxiliary path, the measured input impedance is larger than 133 M[Formula: see text] in the signal bandwidth and reaches 8.2 G[Formula: see text] at DC. With the improved RLD circuit, the measured CMRR is 131 - 144 dB in the signal bandwidth. Under 60-μs pulse width and 130-Hz constant current stimulation (CCS) with ±1-V CMAV and ±50-mV DMAV, the measured THD at the SC Amp output of fabricated AFE LFP chopper amplifier is 1.28%. The measurement results of In vitro agar tests have shown that with ±1.6-mA CCS pulses injecting to agar, the measured THD is 1.69%. Experimental results of both electrical and agar tests have verified that the proposed AFE LFP chopper amplifier has good stimulation artifact tolerance. The proposed CMOS AFE LFP chopper amplifier with analog template removal method is suitable for real-time closed-loop deep drain stimulation (DBS) SoC applications.
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Wang Z, Wang X, Shu G, Yin M, Huang S, Yin M. Power-to-Noise Optimization in the Design of Neural Recording Amplifier Based on Current Scaling, Source Degeneration Resistor, and Current Reuse. BIOSENSORS 2024; 14:111. [PMID: 38392030 PMCID: PMC10887131 DOI: 10.3390/bios14020111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/31/2024] [Accepted: 02/13/2024] [Indexed: 02/24/2024]
Abstract
This article presents the design of a low-power, low-noise neural signal amplifier for neural recording. The structure reduces the current consumption of the amplifier through current scaling technology and lowers the input-referred noise of the amplifier by combining a source degeneration resistor and current reuse technologies. The amplifier was fabricated using a 0.18 μm CMOS MS RF G process. The results show the front-end amplifier exhibits a measured mid-band gain of 40 dB/46 dB and a bandwidth ranging from 0.54 Hz to 6.1 kHz; the amplifier's input-referred noise was measured to be 3.1 μVrms, consuming a current of 3.8 μA at a supply voltage of 1.8 V, with a Noise Efficiency Factor (NEF) of 2.97. The single amplifier's active silicon area is 0.082 mm2.
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Affiliation(s)
- Zhen Wang
- State Key Laboratory of Digital Medical Engineering, School of Biomedical Engineering, Hainan University, Haikou 570100, China; (Z.W.); (X.W.); (G.S.); (M.Y.); (S.H.)
- Key Laboratory of Biomedical Engineering of Hainan Province, One Health Institute, Hainan University, Haikou 570100, China
| | - Xiao Wang
- State Key Laboratory of Digital Medical Engineering, School of Biomedical Engineering, Hainan University, Haikou 570100, China; (Z.W.); (X.W.); (G.S.); (M.Y.); (S.H.)
- Key Laboratory of Biomedical Engineering of Hainan Province, One Health Institute, Hainan University, Haikou 570100, China
| | - Guijun Shu
- State Key Laboratory of Digital Medical Engineering, School of Biomedical Engineering, Hainan University, Haikou 570100, China; (Z.W.); (X.W.); (G.S.); (M.Y.); (S.H.)
- Key Laboratory of Biomedical Engineering of Hainan Province, One Health Institute, Hainan University, Haikou 570100, China
| | - Meng Yin
- State Key Laboratory of Digital Medical Engineering, School of Biomedical Engineering, Hainan University, Haikou 570100, China; (Z.W.); (X.W.); (G.S.); (M.Y.); (S.H.)
- Key Laboratory of Biomedical Engineering of Hainan Province, One Health Institute, Hainan University, Haikou 570100, China
| | - Shoushuang Huang
- State Key Laboratory of Digital Medical Engineering, School of Biomedical Engineering, Hainan University, Haikou 570100, China; (Z.W.); (X.W.); (G.S.); (M.Y.); (S.H.)
- Key Laboratory of Biomedical Engineering of Hainan Province, One Health Institute, Hainan University, Haikou 570100, China
| | - Ming Yin
- State Key Laboratory of Digital Medical Engineering, School of Biomedical Engineering, Hainan University, Haikou 570100, China; (Z.W.); (X.W.); (G.S.); (M.Y.); (S.H.)
- Key Laboratory of Biomedical Engineering of Hainan Province, One Health Institute, Hainan University, Haikou 570100, China
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Tang T, Park JH, Zhang L, Ng KA, Yoo J. Group-Chopping: An 8-Channel, 0.04% Gain Mismatch, 2.1 µW 0.017 mm 2 Instrumentation Amplifier for Bio-Potential Recording. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2022; 16:361-371. [PMID: 35412987 DOI: 10.1109/tbcas.2022.3166513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
An 8-channel AFE with a group-chopping instrumentation amplifier (GCIA) is proposed for bio-potential recording applications. The group-chopping technique cascades chopper switches to progressively swap channels and dynamically removes gain mismatch among all channels. An 8-phase non-overlapping clocking scheme is developed and achieves excellent between-channel gain mismatch characteristics. The dynamic offsets among all channels are mitigated by the GCIA as well. The GCIA is the first work that minimizes the gain mismatch across more than two channels. With the help of the group-chopping, combined with an area-efficient open-loop structure, the GCIA shows <0.04% between-channel gain mismatch, the lowest mismatch reported to date. The chip is fabricated in 0.18µm 1P6M CMOS, occupies only 0.017 mm2/Ch., consumes 2.1 μW/Ch. under 0.5 V supply and achieves an NEF of 2.1.
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Sharma K, Sharma R. Low-voltage low-noise gate driven quasi-floating bulk self-cascode current mirror operational transconductance amplifier. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:034717. [PMID: 33820027 DOI: 10.1063/5.0038939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 02/24/2021] [Indexed: 06/12/2023]
Abstract
A gate driven quasi-floating bulk self-cascode current mirror operational transconductance amplifier operable at ±0.9 V supply voltage with DC gain (70 dB), gain bandwidth (250 kHz), noise (2.8 µV/√Hz at 1 Hz), and power consumption (2.96 µW) simulated in 0.18 µm technology has been introduced. Results obtained are superior in comparison to gate driven self-cascode current mirror and regular current mirror OTAs, which can be utilized to improve the performance of analog-mixed signal circuits and systems.
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Affiliation(s)
- K Sharma
- Chitkara University Institute of Engineering and Technology, Chitkara University, Punjab 140401, India
| | - R Sharma
- Chitkara University Institute of Engineering and Technology, Chitkara University, Punjab 140401, India
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Tang T, Yan L, Park JH, Wu H, Zhang L, Li J, Dong Y, Lee BHY, Yoo J. An Active Concentric Electrode for Concurrent EEG Recording and Body-Coupled Communication (BCC) Data Transmission. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2020; 14:1253-1262. [PMID: 33216719 DOI: 10.1109/tbcas.2020.3039353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
This paper presents a wearable active concentric electrode for concurrent EEG monitoring and Body-Coupled Communication (BCC) data transmission. A three-layer concentric electrode eliminates the usage of wires. A common mode averaging unit (CMAU) is proposed to cancel not only the continuous common-mode interference (CMI) but also the instantaneous CMI of up to 51Vpp. The localized potential matching technique removes the ground electrode. An open-loop programmable gain amplifier (OPPGA) with the pseudo-resistor-based RC-divider block is presented to save the silicon area. The presented work is the first reported so far to achieve the concurrent EEG signal recording and BCC-based data transmission. The proposed chip achieves 100 dB CMRR and 110 dB PSRR, occupies 0.044 mm2, and consumes 7.4 μW with an input-referred noise density of 26 nV/√Hz.
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