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Wang Z, Ding Y, Yuan W, Chen H, Chen W, Chen C. Active Claw-Shaped Dry Electrodes for EEG Measurement in Hair Areas. Bioengineering (Basel) 2024; 11:276. [PMID: 38534550 DOI: 10.3390/bioengineering11030276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 03/01/2024] [Accepted: 03/07/2024] [Indexed: 03/28/2024] Open
Abstract
EEG, which can provide brain alteration information via recording the electrical activity of neurons in the cerebral cortex, has been widely used in neurophysiology. However, conventional wet electrodes in EEG monitoring typically suffer from inherent limitations, including the requirement of skin pretreatment, the risk of superficial skin infections, and signal performance deterioration that may occur over time due to the air drying of the conductive gel. Although the emergence of dry electrodes has overcome these shortcomings, their electrode-skin contact impedance is significantly high and unstable, especially in hair-covered areas. To address the above problems, an active claw-shaped dry electrode is designed, moving from electrode morphological design, slurry preparation, and coating to active electrode circuit design. The active claw-shaped dry electrode, which consists of a claw-shaped electrode and active electrode circuit, is dedicated to offering a flexible solution for elevating electrode fittings on the scalp in hair-covered areas, reducing electrode-skin contact impedance and thus improving the quality of the acquired EEG signal. The performance of the proposed electrodes was verified by impedance, active electrode circuit, eyes open-closed, steady-state visually evoked potential (SSVEP), and anti-interference tests, based on EEG signal acquisition. Experimental results show that the proposed claw-shaped electrodes (without active circuit) can offer a better fit between the scalp and electrodes, with a low electrode-skin contact impedance (18.62 KΩ@1 Hz in the hairless region and 122.15 KΩ@1 Hz in the hair-covered region). In addition, with the active circuit, the signal-to-noise ratio (SNR) of the acquiring EEG signal was improved and power frequency interference was restrained, therefore, the proposed electrodes can yield an EEG signal quality comparable to wet electrodes.
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Affiliation(s)
- Zaihao Wang
- Center for Intelligent Medical Electronics, School of Information Science and Technology, Fudan University, Shanghai 200433, China
| | - Yuhao Ding
- Center for Intelligent Medical Electronics, School of Information Science and Technology, Fudan University, Shanghai 200433, China
| | - Wei Yuan
- Center for Intelligent Medical Equipment and Devices, Institute for Innovative Medical Devices, School of Biomedical Engineering, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
- Suzhou Institute for Advanced Research, University of Science and Technology of China, Suzhou 215123, China
| | - Hongyu Chen
- Center for Intelligent Medical Electronics, School of Information Science and Technology, Fudan University, Shanghai 200433, China
| | - Wei Chen
- School of Biomedical Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Chen Chen
- Human Phenome Institute, Fudan University, Shanghai 201203, China
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Rodriguez‐Falces J, Etxaleku S, Trajano GS, Setuain I. The contribution of the tendon electrode to M-wave characteristics in the biceps brachii, vastus lateralis and tibialis anterior. Exp Physiol 2023; 108:1548-1559. [PMID: 37988249 PMCID: PMC10988423 DOI: 10.1113/ep091472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 10/30/2023] [Indexed: 11/23/2023]
Abstract
In some compound muscle action potentials (M waves) recorded using the belly-tendon configuration, the tendon electrode makes a noticeable contribution to the M wave. However, this finding has only been demonstrated in some hand and foot muscles. Here, we assessed the contribution of the tendon potential to the amplitude of the vastus lateralis, biceps brachii and tibialis anterior M waves, and we also examined the role of this tendon potential in the shoulder-like feature appearing in most M waves. M waves were recorded separately at the belly and tendon locations of the vastus lateralis, biceps brachii and tibialis anterior from 38 participants by placing the reference electrode at a distant (contralateral) site. The amplitude of the M waves and the latency of their peaks and shoulders were measured. In the vastus lateralis, the tendon potential was markedly smaller in amplitude (∼75%) compared to the belly M wave (P = 0.001), whereas for the biceps brachii and tibialis anterior, the tendon and belly potentials had comparable amplitudes. In the vastus lateralis, the tendon potential showed a small positive peak coinciding in latency with the shoulder of the belly-tendon M wave, whilst in the biceps brachii and tibialis anterior, the tendon potential showed a clear negative peak which coincided in latency with the shoulder. The tendon potential makes a significant contribution to the belly-tendon M waves of the biceps brachii and tibialis anterior muscles, but little contribution to the vastus lateralis M waves. The shoulder observed in the belly-tendon M wave of the vastus lateralis is caused by the belly potential, the shoulder in the biceps brachii M wave is generated by the tendon potential, whereas the shoulder in the tibialis anterior M wave is caused by both the tendon and belly potentials. NEW FINDINGS: What is the central question of this study? Does a tendon electrode make a noticeable contribution to the belly-tendon M wave in the vastus lateralis, biceps brachii and tibialis anterior muscles? What is the main finding and its importance? Because the patellar tendon potential is small in amplitude, it hardly influences the amplitude and shape of the belly-tendon M wave of the vastus lateralis. However, for the biceps brachii and tibialis anterior muscles, the potentials at the tendon sites show a large amplitude, and thus have a great impact on the corresponding belly-tendon M waves.
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Affiliation(s)
- Javier Rodriguez‐Falces
- Department of Electrical and Electronical EngineeringPublic University of NavarraPamplonaSpain
| | - Saioa Etxaleku
- Clinical Research DepartmentTDN, Orthopedic Surgery and Advanced Rehabilitation CenterMutilvaSpain
| | - Gabriel S. Trajano
- Faculty of Health, School of Exercise and Nutrition SciencesQueensland University of Technology (QUT)BrisbaneQueenslandAustralia
| | - Igor Setuain
- Clinical Research DepartmentTDN, Orthopedic Surgery and Advanced Rehabilitation CenterMutilvaSpain
- Department of Health SciencesPublic University of NavarrePamplonaSpain
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Nguyen XT, Ali M, Lee JW. 3.6 mW Active-Electrode ECG/ETI Sensor System Using Wideband Low-Noise Instrumentation Amplifier and High Impedance Balanced Current Driver. Sensors (Basel) 2023; 23:2536. [PMID: 36904738 PMCID: PMC10007594 DOI: 10.3390/s23052536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 02/17/2023] [Accepted: 02/22/2023] [Indexed: 06/18/2023]
Abstract
An active electrode (AE) and back-end (BE) integrated system for enhanced electrocardiogram (ECG)/electrode-tissue impedance (ETI) measurement is proposed. The AE consists of a balanced current driver and a preamplifier. To increase the output impedance, the current driver uses a matched current source and sink, which operates under negative feedback. To increase the linear input range, a new source degeneration method is proposed. The preamplifier is realized using a capacitively-coupled instrumentation amplifier (CCIA) with a ripple-reduction loop (RRL). Compared to the traditional Miller compensation, active frequency feedback compensation (AFFC) achieves bandwidth extension using the reduced size of the compensation capacitor. The BE performs three types of signal sensing: ECG, band power (BP), and impedance (IMP) data. The BP channel is used to detect the Q-, R-, and S-wave (QRS) complex in the ECG signal. The IMP channel measures the resistance and reactance of the electrode-tissue. The integrated circuits for the ECG/ETI system are realized in the 180 nm CMOS process and occupy a 1.26 mm2 area. The measured results show that the current driver supplies a relatively high current (>600 μApp) and achieves a high output impedance (1 MΩ at 500 kHz). The ETI system can detect resistance and capacitance in the ranges of 10 mΩ-3 kΩ and 100 nF-100 μF, respectively. The ECG/ETI system consumes 3.6 mW using a single 1.8 V supply.
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Chételat O, Rapin M, Bonnal B, Fivaz A, Wacker J, Sporrer B. Remotely Powered Two-Wire Cooperative Sensors for Biopotential Imaging Wearables. Sensors (Basel) 2022; 22:8219. [PMID: 36365916 PMCID: PMC9658661 DOI: 10.3390/s22218219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 10/17/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
Biopotential imaging (e.g., ECGi, EEGi, EMGi) processes multiple potential signals, each requiring an electrode applied to the body's skin. Conventional approaches based on individual wiring of each electrode are not suitable for wearable systems. Cooperative sensors solve the wiring problem since they consist of active (dry) electrodes connected by a two-wire parallel bus that can be implemented, for example, as a textile spacer with both sides made conductive. As a result, the cumbersome wiring of the classical star arrangement is replaced by a seamless solution. Previous work has shown that potential reference, current return, synchronization, and data transfer functions can all be implemented on a two-wire parallel bus while keeping the noise of the measured biopotentials within the limits specified by medical standards. We present the addition of the power supply function to the two-wire bus. Two approaches are discussed. One of them has been implemented with commercially available components and the other with an ASIC. Initial experimental results show that both approaches are feasible, but the ASIC approach better addresses medical safety concerns and offers other advantages, such as lower power consumption, more sensors on the two-wire bus, and smaller size.
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Affiliation(s)
- Olivier Chételat
- CSEM, Electronics/Systems/Digital Health, Jaquet-Droz 1, 2002 Neuchâtel, Switzerland
| | - Michaël Rapin
- CSEM, Electronics/Systems/Digital Health, Jaquet-Droz 1, 2002 Neuchâtel, Switzerland
| | - Benjamin Bonnal
- CSEM, Electronics/Systems/Digital Health, Jaquet-Droz 1, 2002 Neuchâtel, Switzerland
| | - André Fivaz
- CSEM, Electronics/Systems/Digital Health, Jaquet-Droz 1, 2002 Neuchâtel, Switzerland
| | - Josias Wacker
- CSEM, Electronics/Systems/Digital Health, Jaquet-Droz 1, 2002 Neuchâtel, Switzerland
| | - Benjamin Sporrer
- CSEM, Integrated & Wireless Systems/System-on-Chip/ASIC for the Edge, Technopark, Technoparkstrasse 1, 8005 Zürich, Switzerland
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Shull G, Shin Y, Viventi J, Jochum T, Morizio J, Seo KJ, Fang H. Design and Simulation of a Low Power 384-channel Actively Multiplexed Neural Interface. IEEE Biomed Circuits Syst Conf 2022; 2022:477-481. [PMID: 37431519 PMCID: PMC10331316 DOI: 10.1109/biocas54905.2022.9948553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/12/2023]
Abstract
Brain computer interfaces (BCIs) provide clinical benefits including partial restoration of lost motor control, vision, speech, and hearing. A fundamental limitation of existing BCIs is their inability to span several areas (> cm2) of the cortex with fine (<100 μm) resolution. One challenge of scaling neural interfaces is output wiring and connector sizes as each channel must be independently routed out of the brain. Time division multiplexing (TDM) overcomes this by enabling several channels to share the same output wire at the cost of added noise. This work leverages a 130-nm CMOS process and transfer printing to design and simulate a 384-channel actively multiplexed array, which minimizes noise by adding front end filtering and amplification to every electrode site (pixel). The pixels are 50 μm × 50 μm and enable recording of all 384 channels at 30 kHz with a gain of 22.3 dB, noise of 9.57 μV rms, bandwidth of 0.1 Hz - 10 kHz, while only consuming 0.63 μW/channel. This work can be applied broadly across neural interfaces to create high channel-count arrays and ultimately improve BCIs.
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Affiliation(s)
- Gabriella Shull
- Department of Biomedical Engineering, Duke University, Durham, North Carolina
| | - Yieljae Shin
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Jonathan Viventi
- Department of Biomedical Engineering, Duke University, Durham, North Carolina
| | - Thomas Jochum
- Department of Biomedical Engineering, Duke University, Durham, North Carlonia
| | - James Morizio
- Department of Electrical Engineering, Duke University, Durham, North Carolina
| | - Kyung Jin Seo
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Hui Fang
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
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Link T. Guidelines in Practice: Electrosurgical Safety. AORN J 2021; 114:60-72. [PMID: 34181252 DOI: 10.1002/aorn.13421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 03/12/2021] [Indexed: 11/05/2022]
Abstract
Surgeons routinely use electrosurgical devices to cut and coagulate tissue during surgical procedures. However, hazards associated with electrosurgery (eg, burns, electrical shock, fire) can place patients or personnel at risk. Perioperative nurses should standardize processes, preoperatively assess the risks for electrosurgical injuries, and participate in education activities on electrosurgical safety to help prevent injuries from occurring. The AORN "Guideline for electrosurgical safety" provides guidance to perioperative personnel for safe use of electrosurgical units, electrocautery devices, and argon-enhanced coagulators. This article discusses prevention of electrosurgical unit injuries, including those that can be caused by electrosurgical accessories. A scenario describes how a team investigating two incidents related to use of electrosurgery uses an assessment tool to identify risks for injury and includes a report of these risks in the surgical briefing. Perioperative RNs should review the entire guideline for additional information when creating and updating policies and procedures for electrosurgical safety.
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Peng S, Xu K, Chen W. Comparison of Active Electrode Materials for Non-Contact ECG Measurement. Sensors (Basel) 2019; 19:s19163585. [PMID: 31426518 PMCID: PMC6720752 DOI: 10.3390/s19163585] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 08/11/2019] [Accepted: 08/14/2019] [Indexed: 11/16/2022]
Abstract
For long-term and more convenience electrocardiograph (ECG) monitoring, an active- electrode-based ECG monitoring system, which can measure ECG through clothes, is proposed in this paper. The hardware of the system includes active electrodes, signal processing and data transmission modules and the software mainly includes a denoising algorithm based on empirical mode decomposition (EMD). Then the proposed system was verified using the comparison of the ECG signals measured synchronously by active electrodes and Ag/AgCl electrodes. In addition, three flexible materials, including conductive textile, copper foil tape and a flexible printed circuit (FPC) are developed for the sensing layer with active electrodes. To compare the performance of these three materials for the sensing layer, the ECG signals of 10 subjects were measured by different materials in three postures and several indexes for quality evaluation were calculated. Results show that effective and clear ECG waveforms can be measured by all three kinds of materials and the quality of ECG signals measured by FPC is the best by conducting a significant t-test for signal quality indexes of three materials.
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Affiliation(s)
- Shun Peng
- Center for Intelligent Medical Electronics, School of Information Science and Technology, Fudan University, Shanghai 200433, China
| | - Ke Xu
- Center for Intelligent Medical Electronics, School of Information Science and Technology, Fudan University, Shanghai 200433, China
| | - Wei Chen
- Center for Intelligent Medical Electronics, School of Information Science and Technology, Fudan University, Shanghai 200433, China.
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Raducanu BC, Yazicioglu RF, Lopez CM, Ballini M, Putzeys J, Wang S, Andrei A, Rochus V, Welkenhuysen M, Helleputte NV, Musa S, Puers R, Kloosterman F, Hoof CV, Fiáth R, Ulbert I, Mitra S. Time Multiplexed Active Neural Probe with 1356 Parallel Recording Sites. Sensors (Basel) 2017; 17:E2388. [PMID: 29048396 PMCID: PMC5677417 DOI: 10.3390/s17102388] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 09/26/2017] [Accepted: 10/16/2017] [Indexed: 12/31/2022]
Abstract
We present a high electrode density and high channel count CMOS (complementary metal-oxide-semiconductor) active neural probe containing 1344 neuron sized recording pixels (20 µm × 20 µm) and 12 reference pixels (20 µm × 80 µm), densely packed on a 50 µm thick, 100 µm wide, and 8 mm long shank. The active electrodes or pixels consist of dedicated in-situ circuits for signal source amplification, which are directly located under each electrode. The probe supports the simultaneous recording of all 1356 electrodes with sufficient signal to noise ratio for typical neuroscience applications. For enhanced performance, further noise reduction can be achieved while using half of the electrodes (678). Both of these numbers considerably surpass the state-of-the art active neural probes in both electrode count and number of recording channels. The measured input referred noise in the action potential band is 12.4 µVrms, while using 678 electrodes, with just 3 µW power dissipation per pixel and 45 µW per read-out channel (including data transmission).
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Affiliation(s)
- Bogdan C Raducanu
- Imec, 3001 Leuven, Belgium.
- Electrical Engineering Department-ESAT, KU Leuven, 3001 Leuven, Belgium.
| | | | | | | | | | | | | | | | | | | | | | - Robert Puers
- Imec, 3001 Leuven, Belgium.
- Electrical Engineering Department-ESAT, KU Leuven, 3001 Leuven, Belgium.
| | - Fabian Kloosterman
- Faculty of Psychology and Educational Sciences, KU Leuven, 3000 Leuven, Belgium.
- Neuro-electronics Research Flanders, 3001 Leuven, Belgium.
- VIB, 3000 Leuven, Belgium.
| | - Chris van Hoof
- Imec, 3001 Leuven, Belgium.
- Electrical Engineering Department-ESAT, KU Leuven, 3001 Leuven, Belgium.
| | - Richárd Fiáth
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, H-1117 Budapest, Hungary.
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, H-1083 Budapest, Hungary.
| | - István Ulbert
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, H-1117 Budapest, Hungary.
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, H-1083 Budapest, Hungary.
| | - Srinjoy Mitra
- School of Engineering, University of Glasgow, Glasgow G10 8QQ, UK.
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