scholarly journals Comprehensive Optimization of the Tripolar Concentric Ring Electrode Based on Its Finite Dimensions Model and Confirmed by Finite Element Method Modeling

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5881
Author(s):  
Oleksandr Makeyev ◽  
Yiyao Ye-Lin ◽  
Gema Prats-Boluda ◽  
Javier Garcia-Casado
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Estimation Error ◽  
Optimization Criterion ◽  
Ring Electrode ◽  
Optimal Configuration ◽  
Concentric Ring ◽  
Finite Element Method Modeling ◽  
First Time ◽  
Element Method

The optimization performed in this study is based on the finite dimensions model of the concentric ring electrode as opposed to the negligible dimensions model used in the past. This makes the optimization problem comprehensive, as all of the electrode parameters including, for the first time, the radius of the central disc and individual widths of concentric rings, are optimized simultaneously. The optimization criterion used is maximizing the accuracy of the surface Laplacian estimation, as the ability to estimate the Laplacian at each electrode constitutes primary biomedical significance of concentric ring electrodes. For tripolar concentric ring electrodes, the optimal configuration was compared to previously proposed linearly increasing inter-ring distances and constant inter-ring distances configurations of the same size and based on the same finite dimensions model. The obtained analytic results suggest that previously proposed configurations correspond to almost two-fold and more than three-fold increases in the Laplacian estimation error compared with the optimal configuration proposed in this study, respectively. These analytic results are confirmed using finite element method modeling, which was adapted to the finite dimensions model of the concentric ring electrode for the first time. Moreover, the finite element method modeling results suggest that optimal electrode configuration may also offer improved sensitivity and spatial resolution.

scholarly journals Comprehensive Optimization of the Tripolar Concentric Ring Electrode with Respect to the Accuracy of Laplacian Estimation Based on the Finite Dimensions Model of the Electrode

2020 ◽  
Vol 2 (1) ◽  
pp. 56
Author(s):  
Oleksandr Makeyev
Keyword(s):  
Optimization Problem ◽  
Estimation Error ◽  
Optimization Criterion ◽  
Ring Electrode ◽  
Optimal Configuration ◽  
Concentric Ring ◽  
Surface Laplacian ◽  
The Past ◽  
Central Disc ◽  
First Time

Optimization performed in this study is based on the finite dimensions model of the concentric ring electrode as opposed to the negligible dimensions model widely used in the past. This makes the optimization problem comprehensive since all of the electrode parameters, including, for the first time, the radius of the central disc and individual widths of concentric rings, are optimized simultaneously. The optimization criterion used is maximizing the accuracy of the surface Laplacian estimation since the ability to estimate the Laplacian at each electrode constitutes the primary biomedical significance of concentric ring electrodes. Even though the obtained results and derived principles defining optimal electrode configurations are illustrated on tripolar (two concentric rings) electrodes, they were also confirmed for quadripolar (three rings) and pentapolar (four rings) electrodes and are likely to continue to hold for any higher number of concentric rings. For tripolar concentric ring electrodes, the optimal configuration was compared to previously proposed, linearly increasing inter-ring distances and constant inter-ring distances in configurations of the same size and based on the same finite dimensions model of the electrode. The obtained results suggest that previously proposed configurations correspond to almost two-fold and more than three-fold increases in Laplacian estimation error, respectively, compared to the optimal configuration proposed in this study.

Finite element method modeling of craniofacial growth

1985 ◽  
Vol 87 (6) ◽  
pp. 453-472 ◽  
Author(s):  
Melvin L. Moss ◽  
Richard Skalak ◽  
Himanshu Patel ◽  
Kasturi Sen ◽  
Letty Moss-Salentijn ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Craniofacial Growth ◽  
Finite Element Method Modeling ◽  
Element Method

Development of SFEM-Pre: A Novel Preprocessor for Model Creation for the Smoothed Finite Element Method

2019 ◽  
Vol 17 (02) ◽  
pp. 1845002 ◽  
Author(s):  
J. F. Zhang ◽  
R. P. Niu ◽  
Y. F. Zhang ◽  
C. Q. Wang ◽  
M. Li ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Complex Geometry ◽  
Three Dimensional ◽  
Efficient Computation ◽  
Practical Engineering ◽  
Smoothed Finite Element Method ◽  
2D And 3D ◽  
First Time ◽  
Element Method

Smoothed finite element method (S-FEM) is a new general numerical method which has been applied to solve various practical engineering problems. It combines standard finite element method (FEM) and meshfree techniques based on the weaken-weak (W2) formulation. This project, for the first time, develops a preprocessor software package SFEM-Pre for creating types of two-dimensional (2D) and three-dimensional (3D) S-FEM models following strictly the S-FEM theory. Because the software architecture of our 3D processor is the same as our 2D preprocessor, we will mainly introduce the 2D preprocessor in terms of software design for easier description, but the examples will include both 2D and 3D cases to fully demonstrate and validate the whole preprocessor of S-FEM. Our 2D preprocessor package is equipped with a graphical user interface (GUI) for easy use, and with a connectivity database for efficient computation. Schemes are developed for not only automatically meshes the problem domains using our GUI, but also accepts various geometry files made available from some existing commercial software packages, such as ABAQUS®and HyperMesh®. In order to improve the efficiency of our preprocessor, a parallel triangulation mesh generator has also been developed based on the advancing front technique (AFT) to create triangular meshes for complex geometry, and at the same time to create six types of connectivity needed for various S-FEM models. In addition, a database is implemented in our code to record all these connectivity to avoid duplicated calculation. Finally, intensive numerical experiments are conducted to validate the efficiency, accuracy and stability of our preprocessor codes. It is shown that with our preprocessor, an S-FEM can be created automatically without much human intervention for geometry of arbitrary complexity.

The modified characteristics finite element method for time-dependent Darcy-Brinkman problem

2018 ◽  
Vol 36 (1) ◽  
pp. 356-376 ◽  
Author(s):  
Cheng Liao ◽  
Pengzhan Huang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Double Diffusion ◽  
Diffusion Problem ◽  
Content Type ◽  
Characteristics Method ◽  
Complicated Model ◽  
Velocity Pressure ◽  
First Time ◽  
Element Method

Purpose This study aims to capture the effective behavior of double-diffusion problem, which arises from the combined heat and mass transfer in porous medium and develop the modified characteristics finite element method. Design/methodology/approach The proposed finite element method deals with the nonlinear term temporal term by modified characteristics method. Then, the authors compute the velocity, pressure, temperature and concentration using the decoupled technique. Finally, to show the efficiency of the method, the authors give some numerical examples. Findings From the numerical results, one can see that the method has a good accuracy, which shows that the method can simulate this Darcy–Brinkman problem well. Originality/value The originality lies in the fact that the proposed scheme is the first time for solving the Darcy–Brinkman problem, which is a more complicated model, and includes the velocity, pressure, temperature and concentration.

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