Application of Composite Distributed Electrodes in Cardiographic Sensors

2021 ◽  
Vol 13 ◽  
Author(s):  
Nikolai F. Uvarov ◽  
Boris B. Bokhonov ◽  
Artem S. Ulihin ◽  
Alexander I. Titkov ◽  
Yuriy M. Yukhin ◽  
...  
Keyword(s):  
Wide Frequency Range ◽  
Equivalent Model ◽  
Equivalent Circuits ◽  
Electrode Impedance ◽  
Shape Distortion ◽  
Distributed Parameters ◽  
Real Change ◽  
Electrode Interface ◽  
Double Time ◽  
Constant Phase Elements

Background: An analysis of equivalent circuits used to interpret the impedance of bio-electrode for electrocardiography shows that the best description is achieved using a double-time constant model of the skin-electrode interface. However, for the measurements it is necessary to use equipment with high input impedance, which leads to the loss of information about the real change in the bio-potential. Objective: The aim of the study is to comprehensively investigate and select the equivalent model that are used to interpret the impedance of a composite bioelectrode with distributed parameters. Method: We used theoretical and experimental research methods. Results: It is proposed for measuring bio-potential to use Ag/AgI/Al2O3 electrodes with distributed parameters. Such electrodes are characterized by a higher contact area and their impedance is described in terms of equivalent circuits with constant phase elements (CPE). It was shown that the electrode impedance is well described over a wide frequency range by an equivalent circuit typical for distributed electrodes including two CPE elements. Conclusion: It is experimentally shown that the distributed Ag/AgI/Al2O3 electrode has at least 6 times smaller polarization contribution than a commercial Ag/AgCl cardiographic electrode. It may enable more accurate measurements of bio-potentials providing less pulse shape distortion caused by polarization of electrochemical biosensors.

Combined Frequency Equivalent Model for Power Transmission Network Dynamic Behavior Analysis

2018 ◽  
Vol 19 (2) ◽  
Author(s):  
S. Lakrih ◽  
J. Diouri
Keyword(s):  
Frequency Response ◽  
Behavior Analysis ◽  
Dynamic Behavior ◽  
Power Transmission ◽  
Equivalent Model ◽  
Network Dynamic ◽  
Transmission Network ◽  
Lumped Model ◽  
Distributed Parameters ◽  
The Impact

AbstractThis paper presents a dynamic equivalent model for transmission network dynamic behavior analysis in MATLAB SIMULINK. The electromagnetic frequency response and electromechanical response are combined in the model. The dynamic behavior of distributed parameters line modeled by the EMTP equivalent model is compared with that corresponding to lumped parameter line represented by π model. The aim is to define the frequency band in which the lumped model can accurately represent the distributed parameters model on no load conditions but also when the network is loaded. The proposed equivalent model is explored to investigate the impact of topology on the network dynamics. Besides, the influence of load nature and compensation rate on the driving point frequency response are analyzed analytically and simulated via the proposed model.

scholarly journals DEVELOPMENT AND MODELLING OF HIGH SPREAD CONDUCTIVITY EARTH ELECTRODES FOR COMPLEX EARTHING ARRANGEMENTS

2021 ◽  
pp. 16-22
Author(s):  
Vyacheslav Balalaiev ◽  
Olena Fedoseenko
Keyword(s):  
Reference Model ◽  
Layer Structure ◽  
Potential Method ◽  
Equivalent Model ◽  
Design Parameters ◽  
Electrical Characteristics ◽  
Electric Circuits ◽  
Distributed Parameters ◽  
Normalized Parameters ◽  
Earth Electrode

The analysis of methods for calculating the electrical characteristics of earth electrodes in case of emergency currents of industrial frequency flowing through the elements of earthing arrangements is carried out. A method for improving complex earthing arrangements of electrical installations by optimization of their design parameters is proposed. The proposed method consists in installing an artificial earth electrode with an increased contact area of its surface with the ground, which makes it possible to increase the conductivity of earthing spreading. The use of these electrodes on the territory of projected or operating electrical installations ensures that the values of the normalized parameters of earthing arrangements are brought to permissible values. The use of the method given in the calculations of earthing arrangements requires the replacement of volumetric earth electrodes with a set of linear vertical electrodes. The design model is substantiated by equivalent electrical characteristics relative to the two-layer model of the electrical structure of the earth. The equivalent model was obtained by a given approximation of the electrical characteristics of a set of straight electrodes in the process of increasing their number to the equivalent characteristics of the reference model. In turn, the determination of the characteristics of the reference model was carried out directly by solving the boundary value problem for the potential satisfying Laplace equation using finite difference method. Theoretical investigations using induced potential method and methods of calculation of branched electric circuits with distributed parameters for calculation of electric field and resistance of the complex non-equipotential earth electrode in the ground with two-layer structure have been carried out. The developed electrodes of increased spread conductivity are mounted as experimental samples and are involved in the formation of the electrical characteristics of the earthing arrangements.

scholarly journals Fractional-Order Chaotic Memory with Wideband Constant Phase Elements

Entropy ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 422 ◽  
Author(s):  
Jiri Petrzela
Keyword(s):  
Fractional Order ◽  
Resonant Tunneling ◽  
Chaotic Behavior ◽  
Phase Error ◽  
Wide Frequency Range ◽  
Chaotic Oscillator ◽  
Tunneling Diodes ◽  
Constant Phase Elements ◽  
Very High ◽  
Structurally Stable

This paper provides readers with three partial results that are mutually connected. Firstly, the gallery of the so-called constant phase elements (CPE) dedicated for the wideband applications is presented. CPEs are calculated for 9° (decimal orders) and 10° phase steps including ¼, ½, and ¾ orders, which are the most used mathematical orders between zero and one in practice. For each phase shift, all necessary numerical values to design fully passive RC ladder two-terminal circuits are provided. Individual CPEs are easily distinguishable because of a very high accuracy; maximal phase error is less than 1.5° in wide frequency range beginning with 3 Hz and ending with 1 MHz. Secondly, dynamics of ternary memory composed by a series connection of two resonant tunneling diodes is investigated and, consequently, a robust chaotic behavior is discovered and reported. Finally, CPEs are directly used for realization of fractional-order (FO) ternary memory as lumped chaotic oscillator. Existence of structurally stable strange attractors for different orders is proved, both by numerical analyzed and experimental measurement.

Measurement of the electrode impedance in a wide frequency range using a pseudo-random noise

1975 ◽  
Vol 20 (8) ◽  
pp. 599-601 ◽  
Author(s):  
G. Blanc ◽  
I. Epelboin ◽  
C. Gabrielli ◽  
M. Keddam
Keyword(s):  
Random Noise ◽  
Wide Frequency Range ◽  
Electrode Impedance ◽  
Frequency Range

scholarly journals The origin of constant phase element in equivalent circuit of MIS (n) GaAs structures

2020 ◽  
Vol 31 (21) ◽  
pp. 19106-19118
Author(s):  
Łukasz Drewniak ◽  
Stanisław Kochowski
Keyword(s):  
Impedance Spectroscopy ◽  
Constant Phase Element ◽  
Deep Level ◽  
Frequency Dispersion ◽  
Interface States ◽  
Equivalent Circuits ◽  
Electrical Characteristics ◽  
In Series ◽  
Constant Phase Elements ◽  
Large Frequency

AbstractThe Au/Pd/Ti–SiO2-(n) GaAs properties have been analyzed via impedance spectroscopy (IS), as well as DLTS and ICTS, to identify the origin of electron processes responsible for existence of constant phase elements (CPE) in an equivalent circuits of that structure. We showed that CPEs connected in series with resistance represents the electron processes associated with deep levels in GaAs and/or interface states at SiO2-(n) GaAs interface, depending on the value of n of CPE parameter. CPE with n close to 1 characterize the electron processes associated with EL2 deep level, and CPE with n = 0.5–0.65 the complex electron processes associated with EL3 deep level and interface states together. We stated that constant phase elements in equivalent circuits of MIS-GaAs structures with large frequency dispersion of electrical characteristics can be the result of more than one electron process.

scholarly journals Effective Simulation Approach for Lightning Impulse Voltage Tests of Reactor and Transformer Windings

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5399
Author(s):  
Piyapon Tuethong ◽  
Peerawut Yutthagowith ◽  
Anantawat Kunakorn
Keyword(s):  
Equivalent Circuit ◽  
Simulation Method ◽  
Wide Frequency Range ◽  
Equivalent Circuits ◽  
Standard Requirement ◽  
Vector Fitting ◽  
Fitting Algorithm ◽  
Impulse Voltage ◽  
Lightning Impulse ◽  
Combined Algorithm

In this paper, an effective simulation method for lightning impulse voltage tests of reactor and transformer windings is presented. The method is started from the determination of the realized equivalent circuit of the considered winding in the wide frequency range from 10 Hz to 10 MHz. From the determined equivalent circuit and with the use of the circuit simulator, the circuit parameters in the impulse generator circuit are adjusted to obtain the waveform parameters according to the standard requirement. The realized equivalent circuits of windings for impulse voltage tests have been identified. The identification approach starts from equivalent circuit determination based on a vector fitting algorithm. However, the vector fitting algorithm with the equivalent circuit extraction is not guaranteed to obtain the realized equivalent circuit. From the equivalent circuit, it is possible that there are some negative parameters of resistance, inductance, and capacitance. Using such circuit parameters from the vector fitting approach as the beginning circuit parameters, a genetic algorithm is employed for searching equivalent circuit parameters with the constraints of positive values. The realized equivalent circuits of the windings can be determined. The validity of the combined algorithm is confirmed by comparison of the simulated results by the determined circuit model and the experimental results, and good agreement is observed. The proposed approach is very useful in lightning impulse tests on the reactor and transformer windings.

scholarly journals Compact Wide Frequency Range Fractional-Order Models of Human Body Impedance against Contact Currents

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Todd J. Freeborn ◽  
Ahmed S. Elwakil ◽  
Brent Maundy
Keyword(s):  
Least Squares ◽  
Fractional Order ◽  
Human Body ◽  
Nonlinear Least Squares ◽  
Wide Frequency Range ◽  
Frequency Range ◽  
Model Simulations ◽  
Integer Order ◽  
Body Impedance ◽  
Constant Phase Elements

Three circuit models using constant phase elements are investigated to represent the human body impedance against contact currents from 40 Hz to 110 MHz. The parameters required to represent the impedance are determined using a nonlinear least squares fitting (NLSF) applied to the averaged human body impedance dataset. The three fractional-order models with 4, 6, and 7 parameters are compared to an already existing integer-order, 11-parameter model. Simulations of the fractional-order models impedance are presented and discussed along with their limitations.

A Connection Between Anomalous Poisson–Nernst–Planck Model and Equivalent Circuits with Constant Phase Elements

2013 ◽  
Vol 117 (45) ◽  
pp. 23685-23690 ◽  
Author(s):  
E. K. Lenzi ◽  
J. L. de Paula ◽  
F. R. G. B. Silva ◽  
L. R. Evangelista
Keyword(s):  
Equivalent Circuits ◽  
Constant Phase Elements
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