Novel Dry Polymer Foam Electrodes for Long-Term EEG Measurement
01 May 2011-IEEE Transactions on Biomedical Engineering (IEEE Trans Biomed Eng)-Vol. 58, Iss: 5, pp 1200-1207
TL;DR: A novel dry foam-based electrode, fabricated by electrically conductive polymer foam covered by a conductive fabric, performs better for long-term EEG measurement, and is practicable for daily life applications.
Abstract: A novel dry foam-based electrode for long-term EEG measurement was proposed in this study. In general, the conventional wet electrodes are most frequently used for EEG measurement. However, they require skin preparation and conduction gels to reduce the skin-electrode contact impedance. The aforementioned procedures when wet electrodes were used usually make trouble to users easily. In order to overcome the aforesaid issues, a novel dry foam electrode, fabricated by electrically conductive polymer foam covered by a conductive fabric, was proposed. By using conductive fabric, which provides partly polarizable electric characteristic, our dry foam electrode exhibits both polarization and conductivity, and can be used to measure biopotentials without skin preparation and conduction gel. In addition, the foam substrate of our dry electrode allows a high geometric conformity between the electrode and irregular scalp surface to maintain low skin-electrode interface impedance, even under motion. The experimental results presented that the dry foam electrode performs better for long-term EEG measurement, and is practicable for daily life applications.
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TL;DR: The term "lab-on-skin" is introduced to describe a set of electronic devices that have physical properties, such as thickness, thermal mass, elastic modulus, and water-vapor permeability, which resemble those of the skin, which provide accurate, non-invasive, long-term, and continuous health monitoring.
Abstract: Skin is the largest organ of the human body, and it offers a diagnostic interface rich with vital biological signals from the inner organs, blood vessels, muscles, and dermis/epidermis. Soft, flexible, and stretchable electronic devices provide a novel platform to interface with soft tissues for robotic feedback and control, regenerative medicine, and continuous health monitoring. Here, we introduce the term “lab-on-skin” to describe a set of electronic devices that have physical properties, such as thickness, thermal mass, elastic modulus, and water-vapor permeability, which resemble those of the skin. These devices can conformally laminate on the epidermis to mitigate motion artifacts and mismatches in mechanical properties created by conventional, rigid electronics while simultaneously providing accurate, non-invasive, long-term, and continuous health monitoring. Recent progress in the design and fabrication of soft sensors with more advanced capabilities and enhanced reliability suggest an impending t...
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TL;DR: Electronics and sensors that can be conformally and robustly integrated onto the surface of the skin offer capabilities in biocompatible, non-invasive measurement that lie beyond those available with conventional, point-contact electrode interfaces to the skin.
Abstract: Materials and designs are presented for electronics and sensors that can be conformally and robustly integrated onto the surface of the skin A multifunctional device of this type can record various physiological signals relevant to health and wellness This class of technology offers capabilities in biocompatible, non-invasive measurement that lie beyond those available with conventional, point-contact electrode interfaces to the skin
735 citations
TL;DR: The experimental results indicate that stable patterns of electroencephalogram (EEG) over time for emotion recognition exhibit consistency across sessions; the lateral temporal areas activate more for positive emotions than negative emotions in beta and gamma bands; and the neural patterns of neutral emotions have higher alpha responses at parietal and occipital sites.
Abstract: In this paper, we investigate stable patterns of electroencephalogram (EEG) over time for emotion recognition using a machine learning approach. Up to now, various findings of activated patterns associated with different emotions have been reported. However, their stability over time has not been fully investigated yet. In this paper, we focus on identifying EEG stability in emotion recognition. We systematically evaluate the performance of various popular feature extraction, feature selection, feature smoothing and pattern classification methods with the DEAP dataset and a newly developed dataset called SEED for this study. Discriminative Graph regularized Extreme Learning Machine with differential entropy features achieves the best average accuracies of 69.67 and 91.07 percent on the DEAP and SEED datasets, respectively. The experimental results indicate that stable patterns exhibit consistency across sessions; the lateral temporal areas activate more for positive emotions than negative emotions in beta and gamma bands; the neural patterns of neutral emotions have higher alpha responses at parietal and occipital sites; and for negative emotions, the neural patterns have significant higher delta responses at parietal and occipital sites and higher gamma responses at prefrontal sites. The performance of our emotion recognition models shows that the neural patterns are relatively stable within and between sessions.
511 citations
Cites background from "Novel Dry Polymer Foam Electrodes f..."
...Many advanceddry electrodes and embedded systems are developed to handle the wearability, portability, and practical use of these systems in real-world applications [20], [21]....
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TL;DR: It is concluded that good quality, single-trial EEG data suitable for mobile brain-computer interfaces can be obtained with affordable hardware.
Abstract: To build a low-cost, small, and wireless electroencephalogram (EEG) system suitable for field recordings, we merged consumer EEG hardware with an EEG electrode cap. Auditory oddball data were obtained while participants walked outdoors on university campus. Single-trial P300 classification with linear discriminant analysis revealed high classification accuracies for both indoor (77%) and outdoor (69%) recording conditions. We conclude that good quality, single-trial EEG data suitable for mobile brain-computer interfaces can be obtained with affordable hardware.
492 citations
TL;DR: The goal of the present paper is to contribute to the effective documentation and communication of advances by providing updated guidelines for conducting and reporting EEG/MEG studies, which include a checklist of key information recommended for inclusion in research reports on EEG/ MEG measures.
Abstract: Electromagnetic data collected using electroencephalography (EEG) and magnetoencephalography (MEG) are of central importance for psychophysiological research. The scope of concepts, methods, and instruments used by EEG/MEG researchers has dramatically increased and is expected to further increase in the future. Building on existing guideline publications, the goal of the present paper is to contribute to the effective documentation and communication of such advances by providing updated guidelines for conducting and reporting EEG/MEG studies. The guidelines also include a checklist of key information recommended for inclusion in research reports on EEG/MEG measures.
485 citations
Cites background or methods from "Novel Dry Polymer Foam Electrodes f..."
...It should also be stated whether the peak was defined as the absolute peak or the local peak (e.g., a point that was greater than the adjacent points even if the adjacent points fell outside the measurement window—see Luck, 2005)....
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...Many investigators have acknowledged this problem and have proposed various methods for addressing it in specific cases (e.g., Luck, 2005)....
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...…decomposition technique, such as ICA or spatiotemporal PCA, discussed in the Principal Component Analysis and Independent Component Analysis section (Spencer, Dien, & Donchin, 1999; for general discussion of techniques for isolating components of interest, see Kappenman & Luck, 2012a; Luck, 2005)....
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...…technique for quantifying these features is important, and there are a variety of measurement techniques available (some described below; see Fabiani, Gratton, & Federmeier, 2007, Handy, 2005, Kappenman & Luck, 2012b, Kiebel, Tallon-Baudry, & Friston, 2005, or Luck, 2005, for more information)....
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References
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Book•
01 Jan 1992
TL;DR: Basic Concepts of Medical Instrumentation (W. Olson).
Abstract: Basic Concepts of Medical Instrumentation Basic Sensors and Principles Amplifiers and Signal Processing The Origin of Biopotentials Biopotential Electrodes Biopotential Amplifiers Blood Pressure and Sound Measurement of Flow and Volume of Blood Measurements of the Respiratory System Chemical Biosensors Clinical Laboratory Instrumentation Medical Imaging Systems Therapeutic and Prosthetic Devices Electrical Safety.
1,674 citations
TL;DR: Evaluating the effect of electrode-scalp impedance on EEG data quality found no significant amplitude change in any EEG frequency bands as scalp-electrode impedance increased, suggesting that high-quality EEG can be recorded without skin abrasion.
900 citations
TL;DR: A quantitative comparison of three types of bioelectrode (wet, dry and insulating) based on tests involving electrode impedance, static interference and motion artefact induced by various means indicates that in many situations the performance of dry andinsulating electrodes compares favourably with wet electrodes.
Abstract: Alternatives to conventional wet electrode types are keenly sought for biomedical use and physiological research, especially when prolonged recording of biosignals is demanded. This paper describes a quantitative comparison of three types of bioelectrode (wet, dry and insulating) based on tests involving electrode impedance, static interference and motion artefact induced by various means. Data were collected simultaneously, and in the same physical environment for all electrode types. Results indicate that in many situations the performance of dry and insulating electrodes compares favourably with wet electrodes. The influence of non-stationary electric fields on shielded dry and insulating electrode types was compared to wet types. It was observed that interference experienced by dry and insulating electrode types was 40 dB and 34 dB less than that experienced by wet electrode types. Similarly, the effect of motion artefact on dry and insulating electrodes was compared to wet types. Artefact levels for dry and insulating electrodes were significantly higher than those for wet types at the beginning of trials conducted. By the end of the trial periods artefact levels for dry and insulating types were lower than wet electrodes by an average of 8.2 dB and 6.8 dB respectively. The reservations expressed in other studies regarding the viability of dry and insulating electrodes for reliable sensing of biosignals are not supported by the work described here.
652 citations
TL;DR: In this paper, the authors developed a drowsiness-estimation system based on electroencephalogram (EEG) by combining independent component analysis (ICA), power-spectrum analysis, correlation evaluations, and linear regression model to estimate a driver's cognitive state when he/she drives a car in a virtual reality (VR)-based dynamic simulator.
Abstract: Preventing accidents caused by drowsiness has become a major focus of active safety driving in recent years. It requires an optimal technique to continuously detect drivers' cognitive state related to abilities in perception, recognition, and vehicle control in (near-) real-time. The major challenges in developing such a system include: 1) the lack of significant index for detecting drowsiness and 2) complicated and pervasive noise interferences in a realistic and dynamic driving environment. In this paper, we develop a drowsiness-estimation system based on electroencephalogram (EEG) by combining independent component analysis (ICA), power-spectrum analysis, correlation evaluations, and linear regression model to estimate a driver's cognitive state when he/she drives a car in a virtual reality (VR)-based dynamic simulator. The driving error is defined as deviations between the center of the vehicle and the center of the cruising lane in the lane-keeping driving task. Experimental results demonstrate the feasibility of quantitatively estimating drowsiness level using ICA-based multistream EEG spectra. The proposed ICA-based method applied to power spectrum of ICA components can successfully (1) remove most of EEG artifacts, (2) suggest an optimal montage to place EEG electrodes, and estimate the driver's drowsiness fluctuation indexed by the driving performance measure. Finally, we present a benchmark study in which the accuracy of ICA-component-based alertness estimates compares favorably to scalp-EEG based.
463 citations
TL;DR: In this article, a polymeric dry electrode that changes its shape in a way that supports the electrode's contact with the skin and does not cause skin irritations or allergic reactions is presented.
Abstract: In this paper, we present a novel polymeric dry electrode that (1) changes its shape in a way that supports the electrode's contact with the skin and (2) that does not cause skin irritations or allergic reactions For a polymeric substrate of electrodes, we have used the elastomer poly(dimethylsiloxane), which is known to be inexpensive, biocompatible, and amenable to micro-molding, and to have excellent gas and water permeability We have established a process by which one can deposit a metal layer on the PDMS substrate, etch the electrode patterns chemically and with good resolution, and package the electrode so that it is easily wearable on the forearm We measured the impedance according to the frequency change and compared the results with those of Ag/AgCl electrodes Afterward, we measured the ECG signal and investigated possible artifacts caused by motion For the feasibility of long-term monitoring, we examined the influence of surface electrodes on the skin after 7 days of ECG monitoring In conclusion, our PDMS-based dry electrode measured the ECG signals with comparatively good fidelity, but showed better skin compatibility after long-term tests We expect that our method for the production of PDMS-based dry electrodes will be broadly applicable to the field of ubiquitous biosignal monitoring
301 citations