Reverse‐curve‐arch‐shaped dry EEG electrode for increased skin–electrode contact area on hairy scalps

2015 ◽  
Vol 51 (21) ◽  
pp. 1643-1645 ◽  
Author(s):  
Jeong Su Lee ◽  
Chung Min Han ◽  
Jee Hoon Kim ◽  
Kwang Suk Park
Keyword(s):  
Contact Area ◽  
Skin Electrode ◽  
Electrode Contact

scholarly journals Numerical Modeling of the Effects of Electrode Spacing and Multilayered Concrete Resistivity on the Apparent Resistivity Measured Using Wenner Method

2020 ◽  
Author(s):  
Karthick Thiyagarajan ◽  
Parikshit Acharya ◽  
Lasitha Piyathilaka ◽  
sarath kodagoda
Keyword(s):  
Contact Area ◽  
Apparent Resistivity ◽  
Resistivity Measurement ◽  
Gaussian Process Regression ◽  
Electrode Spacing ◽  
Electrical Resistivity Measurement ◽  
Resistivity Measurements ◽  
Electrode Contact ◽  
Concrete Resistivity ◽  
Moisture Conditions

Smart Sensing technologies can play an important role in the conditional assessment of concrete sewer pipe linings. In the long-term, the permeation of acids can deteriorate the pipe linings. Currently, there are no proven sensors available to non-invasively estimate the depth of acid permeation in real-time. The electrical resistivity measurement on the surface of the linings can indicate the sub-surface acid moisture conditions. In this study, we consider acid permeated linings as a two resistivity layer concrete sample, where the top resistivity layer is assumed to be acid permeated and the bottom resistivity layer indicates normal moisture conditions. Firstly, we modeled the sensor based on the four-probe Wenner method. The measurements of the developed model were compared with the previous studies for validation. Then, the sensor model was utilized to study the effects of electrode contact area, electrode spacing distance and two resistivity layered concrete on the apparent resistivity measurements. All the simulations were carried out by varying the thickness of top resistivity layer concrete. The simulation study indicated that the electrode contact area has very minimal effects on apparent resistivity measurements. Also, an increase in apparent resistivity measurements was observed when there is an increase in the distance of the electrode spacing. Further, a machine learning approach using Gaussian process regression modeling was formulated to estimate the depth of acid permeated layer

scholarly journals Electrochemical Characteristics Based on Skin-Electrode Contact Pressure for Dry Biomedical Electrodes and the Application to Wearable ECG Signal Acquisition

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Jinzhong Song ◽  
Tianshu Zhou ◽  
Zhonggang Liang ◽  
Ruoxi Liu ◽  
Jianping Guo ◽  
...  
Keyword(s):  
Contact Pressure ◽  
Electrode Pair ◽  
Electrochemical Characteristics ◽  
Polarization Voltage ◽  
Skin Electrode ◽  
Textile Electrodes ◽  
Biomedical Electrodes ◽  
Electrode Contact ◽  
Evaluation Platform ◽  
Electrochemical Evaluation

Based on one simulated skin-electrode electrochemical interface, some electrochemical characteristics based on skin-electrode contact pressure (SECP) for dry biomedical electrodes were analysed and applied in this research. First, 14 electrochemical characteristics including 2 static impedance (SI) characteristics, 11 alternating current impedance (ACI) characteristics and one polarization voltage (PV), and 4 SECP characteristics were extracted in one electrochemical evaluation platform, and their correlation trends were statistically analysed. Second, dry biomedical electrode samples developed by the company and the laboratory, including textile electrodes, Apple watch, AMAZFIT rice health bracelet 1S, and stainless steel electrodes, were placed horizontally and vertically on the “skin” surface of the electrochemical evaluation platform, whose polarization voltages were quantitatively analysed. Third, electrocardiogram (ECG) collection circuits based on an impedance transformation (IT) circuit for textile electrodes were designed, and a wearable ECG acquisition device was designed, which could obtain complete ECG signals. Experimental results showed SECP characteristics for dry electrodes had good correlations with static impedance and ACI characteristics and the better correlation values among 2-10 Hz. In addition, polarization voltages in vertical state were smaller in horizontal state for dry biomedical electrodes, and polarization voltage of electrode pair (PVEP) values for Apple watch bottom was always smaller than ones for Apple watch crown and LMF-2 textile electrode. And the skin-electrode contact impedance of IT textile electrodes was less than the traditional textile electrodes.

scholarly journals GEOMETRICAL ANALYSIS OF LIGHT-EMITTING DIODE FOR ENHANCING EXTRACTION EFFICIENCY

2020 ◽  
Vol 15 (6) ◽  
pp. 68-84
Author(s):  
ADAM SHAARI ◽  
◽  
AHMAD FAKHRURRAZI AHMAD NOORDEN ◽  
SAIFUL NAJMEE MOHAMAD ◽  
SUZAIRI DAUD ◽  
...  
Keyword(s):  
Contact Area ◽  
Indium Tin Oxide ◽  
Extraction Efficiency ◽  
Light Emitting Diode ◽  
Light Extraction ◽  
Light Extraction Efficiency ◽  
Current Spreading ◽  
Light Emitting ◽  
Uniform Current ◽  
Electrode Contact

A non-uniform current spreading in the current spreader can greatly reduce the efficiency of the light-emitting diode (LED). The effects of the electrode contact area to the spreading layer towards extraction efficiency of LED chips is analysed in analytical simulations. Length of current spreading and light extraction efficiency is analysed for variation of contact area. The contact area value is varied by changing the shape of the electrode and the value of width of contact area. The increase in contact area decreases light extraction efficiency as more light are absorbed by the bottom electrode surface. The effective current spreading length for Indium Tin Oxide (ITO) of thickness 300nm is 36.44µm. The 6 strips ‘fork’ design is the most optimum. The design has the most area for photons produced in active region to escape without reducing the area cover with current density. This enables the chip to has more extraction efficiency with more uniform current spreading.

Effects of electrode contact area reduction using an excimer laser

1991 ◽  
Vol 23 (2-4) ◽  
pp. 206-211 ◽  
Author(s):  
S. Tanaka ◽  
S. Okamoto ◽  
K. Nakajima ◽  
N. Shibuya ◽  
K. Okamoto ◽  
...  
Keyword(s):  
Excimer Laser ◽  
Contact Area ◽  
Area Reduction ◽  
Electrode Contact

3D Measurement of Electrode Contact Area in Resistance Spot Welding of Coated Steel

2004 ◽  
Vol 48 (11-12) ◽  
pp. 26-30 ◽  
Author(s):  
I. Polajnar ◽  
D. Bračun ◽  
P. Podržaj ◽  
J. Diaci
Keyword(s):  
Contact Area ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Coated Steel ◽  
3D Measurement ◽  
Resistance Spot ◽  
Electrode Contact
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