scholarly journals Solving the Inter-Ring Distances Optimization Problem for Pentapolar and Sextopolar Concentric Ring Electrodes Based on the Negligible Dimensions Model of the Electrode

2021 ◽  
Vol 10 (1) ◽  
pp. 8
Author(s):  
Oleksandr Makeyev ◽  
Alana Lee ◽  
Ashton Begay
Keyword(s):  
Optimization Problem ◽  
Truncation Error ◽  
Wearable Sensors ◽  
Ring Electrode ◽  
Electrode Design ◽  
Spatial Derivative ◽  
Concentric Ring ◽  
Surface Laplacian ◽  
Wide Range ◽  
Electrophysiological Measurement

Concentric ring electrodes are noninvasive and wearable sensors for electrophysiological measurement capable of estimating the surface Laplacian (second spatial derivative of surface potential) at each electrode. Previously, progress was made toward optimization of inter-ring distances (distances between the recording surfaces of a concentric ring electrode), maximizing the accuracy of the surface Laplacian estimate based on the negligible dimensions model of the electrode. However, this progress was limited to tripolar (number of concentric rings n equal to 2) and quadripolar (n = 3) electrode configurations only. In this study, the inter-ring distances optimization problem is solved for pentapolar (n = 4) and sextopolar (n = 5) concentric ring electrode configurations using a wide range of truncation error percentiles ranging from 1st to 25th. Obtained results also suggest consistency between all the considered concentric ring electrode configurations corresponding to n ranging from 2 to 5 that may allow estimation of optimal ranges of inter-ring distances for electrode configurations with n ≥ 6. Therefore, this study may inform future concentric ring electrode design for n ≥ 4 which is important since the accuracy of surface Laplacian estimation has been shown to increase with an increase in n.

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.

scholarly journals Validating the Comparison Framework for the Finite Dimensions Model of Concentric Ring Electrodes Using Human Electrocardiogram Data

2019 ◽  
Vol 9 (20) ◽  
pp. 4279
Author(s):  
Oleksandr Makeyev ◽  
Mark Musngi ◽  
Larry Moore ◽  
Yiyao Ye-Lin ◽  
Gema Prats-Boluda ◽  
...  
Keyword(s):  
Design Optimization ◽  
Finite Dimension ◽  
Ring Electrode ◽  
Proof Of Concept ◽  
Concentric Ring ◽  
Surface Laplacian ◽  
Central Disc ◽  
Human Volunteers ◽  
The Difference ◽  
Made In

While progress has been made in design optimization of concentric ring electrodes maximizing the accuracy of the surface Laplacian estimation, it was based exclusively on the negligible dimensions model of the electrode. Recent proof of concept of the new finite dimensions model that adds the radius of the central disc and the widths of concentric rings to the previously included number of rings and inter-ring distances provides an opportunity for more comprehensive design optimization. In this study, the aforementioned proof of concept was developed into a framework allowing direct comparison of any two concentric ring electrodes of the same size and with the same number of rings. The proposed framework is illustrated on constant and linearly increasing inter-ring distances tripolar concentric ring electrode configurations and validated on electrocardiograms from 20 human volunteers. In particular, ratios of truncation term coefficients between the two electrode configurations were used to demonstrate the similarity between the negligible and the finite dimension models analytically (p = 0.077). Laplacian estimates based on the two models were calculated on electrocardiogram data for emulation of linearly increasing inter-ring distances tripolar concentric ring electrode. The difference between the estimates was not statistically significant (p >> 0.05) which is consistent with the analytic result.

scholarly journals A Survey of NFC Sensors Based on Energy Harvesting for IoT Applications

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3746 ◽  
Author(s):  
Antonio Lazaro ◽  
Ramon Villarino ◽  
David Girbau
Keyword(s):  
Energy Harvesting ◽  
Integrated Circuits ◽  
Radio Frequency Identification ◽  
Low Cost ◽  
Near Field ◽  
Wearable Sensors ◽  
Cold Chain ◽  
Iot Applications ◽  
Wide Range ◽  
Frequency Identification

In this article, an overview of recent advances in the field of battery-less near-field communication (NFC) sensors is provided, along with a brief comparison of other short-range radio-frequency identification (RFID) technologies. After reviewing power transfer using NFC, recommendations are made for the practical design of NFC-based tags and NFC readers. A list of commercial NFC integrated circuits with energy-harvesting capabilities is also provided. Finally, a survey of the state of the art in NFC-based sensors is presented, which demonstrates that a wide range of sensors (both chemical and physical) can be used with this technology. Particular interest arose in wearable sensors and cold-chain traceability applications. The availability of low-cost devices and the incorporation of NFC readers into most current mobile phones make NFC technology key to the development of green Internet of Things (IoT) applications.

scholarly journals Near-Linear Responsive and Wide-Range Pressure and Stretch Sensor Based on Hierarchical Graphene-Based Structures via Solvent-Free Preparation

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1814 ◽  
Author(s):  
Jian Wang ◽  
Ryuki Suzuki ◽  
Kentaro Ogata ◽  
Takuto Nakamura ◽  
Aixue Dong ◽  
...  
Keyword(s):  
Organic Solvents ◽  
Large Strain ◽  
Rapid Development ◽  
Wearable Sensors ◽  
Human Motion ◽  
Solvent Free ◽  
Gauge Factor ◽  
Wearable Electronics ◽  
Human Motion Detection ◽  
Wide Range

Flexible and wearable electronics have huge potential applications in human motion detection, human–computer interaction, and context identification, which have promoted the rapid development of flexible sensors. So far the sensor manufacturing techniques are complex and require a large number of organic solvents, which are harmful not only to human health but also to the environment. Here, we propose a facile solvent-free preparation toward a flexible pressure and stretch sensor based on a hierarchical layer of graphene nanoplates. The resulting sensor exhibits many merits, including near-linear response, low strain detection limits to 0.1%, large strain gauge factor up to 36.2, and excellent cyclic stability withstanding more than 1000 cycles. Besides, the sensor has an extraordinary pressure range as large as 700 kPa. Compared to most of the reported graphene-based sensors, this work uses a completely environmental-friendly method that does not contain any organic solvents. Moreover, the sensor can practically realize the delicate detection of human body activity, speech recognition, and handwriting recognition, demonstrating a huge potential for wearable sensors.

Non-invasive electrohysterogram recording using flexible concentric ring electrode

2014 ◽  
Author(s):  
Y. Ye-Lin ◽  
J. Alberola-Rubio ◽  
G. Prats-Boluda ◽  
J. M. Bueno Barrachina ◽  
A. Perales ◽  
...  
Keyword(s):  
Ring Electrode ◽  
Concentric Ring ◽  
Non Invasive

Stability and Interpretation of Autoregressive Models of Terrain Topology

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Shannon Wagner ◽  
John B. Ferris
Keyword(s):  
Infinite Impulse Response ◽  
Mathematical Framework ◽  
Spatial Derivative ◽  
Model Order ◽  
Vertical Excitation ◽  
Wide Range ◽  
Principal Source ◽  
Infinite Impulse Response Filter ◽  
The Stability ◽  
Impulse Response Filter

Terrain topology is the principal source of vertical excitation into the vehicle system and must be accurately represented in order to correctly predict the vehicle response. It is desirable to evaluate vehicle models over a wide range of terrain, but it is computationally impractical to simulate long distances of every terrain type. A method to characterize terrain topology is developed in this work so that terrain can be grouped into meaningful sets with similar physical characteristics. Specifically, measured terrain profiles are considered realizations of an underlying stochastic process; an autoregressive model provides the mathematical framework to describe this process. The autocorrelation of the spatial derivative of the terrain profile is examined to determine the form of the model. The required order for the model is determined from the partial autocorrelation of the spatial derivative of the terrain profile. The stability of the model is evaluated and enforced by transforming the autoregressive difference equation into an infinite impulse response filter representation. Finally, the method is applied to a set of U.S. highway profile data and an optimal model order is determined for this application.

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