scholarly journals Conception of a Phantom in Agar-Agar Gel with the Same Bio-Impedance Properties as Human Quadriceps

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5195
Author(s):  
Margaux Peixoto ◽  
Marie-Valérie Moreno ◽  
Nassim Khider
Keyword(s):  
Electrical Properties ◽  
Serious Games ◽  
Test Phase ◽  
The Body ◽  
Anisotropic Model ◽  
Agar Gel ◽  
Dry Electrodes ◽  
Conversion Table ◽  
Dry Electrode ◽  
Validation Tests

The physiology of the patient can be reflected by various data. Serious games, using an intelligent combination, could be based on this data to adjust to the specificities of the patient. Rehabilitation would therefore be personalized to the patient. This smart suit would use dry electrodes in order to be easily usable. Before performing dry electrode validation tests on a population, it is necessary to perform preliminary tests on a phantom. Agar-Agar (AA) gel, combined with NaCl and graphite which directly impact the resistivity and reactance values of the phantom, are generally used. Depending on the part of the body simulated by the phantom, it is necessary to adapt the concentrations of NaCl and graphite in order to obtain values of physiological reactance and resistance. The anisotropy of a muscle must also be considered. Different concentrations of NaCl and graphite have been tested in order to present charts linking the concentrations to the resistance and reactance values of the AA phantom. Electrical properties similar to those of human quadriceps are achieved at a concentration of 7 g/L of NaCl and 60 g/L of graphite. These values can be used as a conversion table to develop an AA phantom with electrical properties similar to different muscles. Furthermore, an AA phantom has an anisotropy of 0° and 90°. This anisotropy corresponds to a human quadriceps, where 0° is the direction of the muscle fiber. This will allow us to study and characterize the behavior of the electrodes on an anisotropic model. Thus it can be used as a first test phase for dry electrodes in order to propose the most suitable conditions for a connected garment application.

scholarly journals Properties of different types of dry electrodes for wearable smart monitoring devices

2020 ◽  
Vol 65 (4) ◽  
pp. 405-415
Author(s):  
Lana Popović-Maneski ◽  
Marija D. Ivanović ◽  
Vladimir Atanasoski ◽  
Marjan Miletić ◽  
Sanja Zdolšek ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Heart Muscle ◽  
Silver Chloride ◽  
Real Life ◽  
Motion Artifacts ◽  
The Body ◽  
Stainless Steel Electrode ◽  
Steel Electrode ◽  
Dry Electrodes ◽  
Dry Electrode

AbstractWearable smart monitors (WSMs) applied for the estimation of electrophysiological signals are of utmost interest for a non-stressed life. WSM which records heart muscle activities could signalize timely a life-threatening event. The heart muscle activities are typically recorded across the heart at the surface of the body; hence, a WSM monitor requires high-quality surface electrodes. The electrodes used in the clinical settings [i.e. silver/silver chloride (Ag/AgCl) with the gel] are not practical for the daily out of clinic usage. A practical WSM requires the application of a dry electrode with stable and reproducible electrical characteristics. We compared the characteristics of six types of dry electrodes and one gelled electrode during short-term recordings sessions (≈30 s) in real-life conditions: Orbital, monolithic polymer plated with Ag/AgCl, and five rectangular shaped 10 × 6 × 2 mm electrodes (Orbital, Ag electrode, Ag/AgCl electrode, gold electrode and stainless-steel AISI304). The results of a well-controlled analysis which considered motion artifacts, line noise and junction potentials suggest that among the dry electrodes Ag/AgCl performs the best. The Ag/AgCl electrode is in average three times better compared with the stainless-steel electrode often used in WSMs.

scholarly journals Dedicated Algorithm for Unobtrusive Fetal Heart Rate Monitoring Using Multiple Dry Electrodes

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4298
Author(s):  
Alessandra Galli ◽  
Elisabetta Peri ◽  
Yijing Zhang ◽  
Rik Vullings ◽  
Myrthe van der Ven ◽  
...  
Keyword(s):  
Heart Rate ◽  
Fetal Heart Rate ◽  
Fetal Heart ◽  
Processing System ◽  
Motion Artifacts ◽  
Accurate Estimation ◽  
Fetal Heart Rate Monitoring ◽  
Dry Electrodes ◽  
Textile Electrodes ◽  
Dry Electrode

Multi-channel measurements from the maternal abdomen acquired by means of dry electrodes can be employed to promote long-term monitoring of fetal heart rate (fHR). The signals acquired with this type of electrode have a lower signal-to-noise ratio and different artifacts compared to signals acquired with conventional wet electrodes. Therefore, starting from the benchmark algorithm with the best performance for fHR estimation proposed by Varanini et al., we propose a new method specifically designed to remove artifacts typical of dry-electrode recordings. To test the algorithm, experimental textile electrodes were employed that produce artifacts typical of dry and capacitive electrodes. The proposed solution is based on a hybrid (hardware and software) pre-processing step designed specifically to remove the disturbing component typical of signals acquired with these electrodes (triboelectricity artifacts and amplitude modulations). The following main processing steps consist of the removal of the maternal ECG by blind source separation, the enhancement of the fetal ECG and identification of the fetal QRS complexes. Main processing is designed to be robust to the high-amplitude motion artifacts that corrupt the acquisition. The obtained denoising system was compared with the benchmark algorithm both on semi-simulated and on real data. The performance, quantified by means of sensitivity, F1-score and root-mean-square error metrics, outperforms the performance obtained with the original method available in the literature. This result proves that the design of a dedicated processing system based on the signal characteristics is necessary for reliable and accurate estimation of the fHR using dry, textile electrodes.

scholarly journals Novel dry electrode EEG headbands for home use: Comparing performance and comfort

2020 ◽  
Vol 6 (3) ◽  
pp. 139-142
Author(s):  
Jens Haueisen ◽  
Patrique Fiedler ◽  
Anna Bernhardt ◽  
Ricardo Gonçalves ◽  
Carlos Fonseca
Keyword(s):  
Brain Activity ◽  
Skin Impedance ◽  
Signal Quality ◽  
The Novel ◽  
Application Time ◽  
Dry Electrodes ◽  
Power Spectral ◽  
Dry Electrode ◽  
Increasing Trend ◽  
Eeg Recordings

AbstractMonitoring brain activity at home using electroencephalography (EEG) is an increasing trend for both medical and non-medical applications. Gel-based electrodes are not suitable due to the gel application requiring extensive preparation and cleaning support for the patient or user. Dry electrodes can be applied without prior preparation by the patient or user. We investigate and compare two dry electrode headbands for EEG acquisition: a novel hybrid dual-textile headband comprising multipin and multiwave electrodes and a neoprene-based headband comprising hydrogel and spidershaped electrodes. We compare the headbands and electrodes in terms of electrode-skin impedance, comfort, electrode offset potential and EEG signal quality. We did not observe considerable differences in the power spectral density of EEG recordings. However, the hydrogel electrodes showed considerably increased impedances and offset potentials, limiting their compatibility with many EEG amplifiers. The hydrogel and spider-shaped electrodes required increased adduction, resulting in a lower wearing comfort throughout the application time compared to the novel headband comprising multipin and multiwave electrodes.

Touch insensitive foraging of Caenorhabditis elegans in a constrained structure

Nematology ◽  
2009 ◽  
Vol 11 (4) ◽  
pp. 551-554
Author(s):  
Jinu Eo ◽  
Kazunori Otobe
Keyword(s):  
Caenorhabditis Elegans ◽  
Natural Habitat ◽  
The Body ◽  
Wild Type ◽  
Agar Gel ◽  
Touch Sensor ◽  
Foraging Pattern

Abstract The objective of this study was to clarify the role of touch sensors in the foraging of Caenorhabditis elegans in a constrained structure. The strains tested included an array of mechanosensory mutants insensitive to touch in the body, tail or nose. The mutants and wild type nematodes repeated forward and backward movement in a micro-moulded substrate as on the surface of agar gel. Differences in the foraging pattern were not obvious among mutant groups having different touch sensor deficit in the substrate, and all strains of nematode successfully moved out of the T-shaped structure after searching the configuration of their environment. The results suggest that the touch sensor is a weak contributor to the performance of the worms when foraging, and the behaviour is governed by intrinsic spontaneous patterns in the absence of any stimuli in natural habitat.

scholarly journals The Effect of Hair Spray Exposure to the Changes in Electrical Properties of Mice Organ

2020 ◽  
Vol 9 (3S) ◽  
pp. 354-358
Keyword(s):  
Dielectric Constant ◽  
Free Radicals ◽  
Electrical Properties ◽  
Organ Damage ◽  
The Body ◽  
Oxidation Reactions ◽  
Cell Components ◽  
Organ Tissue ◽  
Complex Polymers ◽  
The Impact

Human activities at this time tend to use substances that are pollutants and have an impact on health. Pollutants can enter the body through the process of respiration and will disrupt the organ function. Substances that are often used in daily life and potentially as pollutants are hairspray. They contain vinyl acetate and methacrylate complex polymers. Cocamide DEA surfactants in hairspray can cause cancer and produce toxins. The use of hairspray continuously will cause organ damage due to the emergence of secondary metabolites and free radicals. The diagnosis of organ damage in the latest research from various scientists is to utilize the electrical characteristics of the organ. The bioelectric characteristic that can be observed is dielectric constant. Based on the impact of organ damage and suspected changes in organ electrical properties due to exposure to pollutants, a study needs to be conducted to observe changes in the resistivity and dielectric constant in organ tissue in mice exposed to hairspray with cocamide DEA surfactant content. The results showed that the more concentration of exposure given causes increasing the level of damage to the organs. The increasing level of damage is very significant in the changing of the resistivity and dielectric constant value of mice organs. The changing of electrical properties of mice organs is possible due to damage to organ cells caused by increasing reactive oxygen species and free radicals due to oxidation reactions resulting from the interaction of cocamide DEA with cell components.

Electrical Impedance Tomography of Cell Viability in Tissue With Application to Cryosurgery

2004 ◽  
Vol 126 (2) ◽  
pp. 305-309 ◽  
Author(s):  
Rafael Davalos ◽  
Boris Rubinsky
Keyword(s):  
Electrical Properties ◽  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Cell Damage ◽  
Membrane Integrity ◽  
The Body ◽  
Impedance Tomography ◽  
Cell Membrane Integrity ◽  
Minimally Invasive Surgical Procedure ◽  
Minimally Invasive Surgical

Tissue damage that is associated with the loss of cell membrane integrity should alter the bulk electrical properties of the tissue. This study shows that electrical impedance tomography (EIT) should be able to detect and image necrotic tissue inside the body due to the permeabilization of the membrane to ions. Cryosurgery, a minimally invasive surgical procedure that uses freezing to destroy undesirable tissue, was used to investigate the hypothesis. Experimental results with liver tissue demonstrate that cell damage during freezing results in substantial changes in tissue electrical properties. Two-dimensional EIT simulations of liver cryosurgery, which employ the experimental data, demonstrate the feasibility of this application.

Validation of the Index to Determine Design Parameters of a WEC for the Cost Optimization of a Wave Farm

2015 ◽  
Author(s):  
Takashi Okamoto ◽  
Yutaro Fukaya ◽  
Yasushi Higo
Keyword(s):  
Cost Optimization ◽  
Energy Conversion Efficiency ◽  
The Body ◽  
Farm Size ◽  
Design Parameters ◽  
Parameter Combination ◽  
Index Value ◽  
The Cost ◽  
Validation Tests ◽  
Wave Farm

An index to estimate the cost of electricity (COE) generated by a wave farm from the design parameters of a wave energy converter (WEC), such as the body size and the generator capacity, was examined to show the validity of index value in this study. The validation tests are performed for three different wave farm settings at three different locations. The result displays the potential of index to capture the trend of COE value especially when the wave farm size is small. The calculation result of COE reveals that the parameter combination to give better profitability is determined by the balance between WEC construction fee and installation fee. So, it would be different from the optimum size to have the best energy conversion efficiency. It also explains the shift of parameter combination to give the better profitability when the size of wave farm is changed. However, the index contains certain level of error because of the lack of this feature. Therefore, the error becomes larger when the size of wave farm becomes larger. As a result, it was found that the modification of the index is needed to improve the accuracy by including the cost related to the number of buoys in the wave farm.

scholarly journals The Dry Revolution: Evaluation of Three Different EEG Dry Electrode Types in Terms of Signal Spectral Features, Mental States Classification and Usability

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1365 ◽  
Author(s):  
Gianluca Di Flumeri ◽  
Pietro Aricò ◽  
Gianluca Borghini ◽  
Nicolina Sciaraffa ◽  
Antonello Di Florio ◽  
...  
Keyword(s):  
Mental States ◽  
Signal Quality ◽  
Multiple Points ◽  
Dry Electrodes ◽  
Dry Electrode ◽  
Common Opinion ◽  
Comprehensive Comparison ◽  
The Common ◽  
Points Of View ◽  
Neuroimaging Techniques

One century after the first recording of human electroencephalographic (EEG) signals, EEG has become one of the most used neuroimaging techniques. The medical devices industry is now able to produce small and reliable EEG systems, enabling a wide variety of applications also with no-clinical aims, providing a powerful tool to neuroscientific research. However, these systems still suffer from a critical limitation, consisting in the use of wet electrodes, that are uncomfortable and require expertise to install and time from the user. In this context, dozens of different concepts of EEG dry electrodes have been recently developed, and there is the common opinion that they are reaching traditional wet electrodes quality standards. However, although many papers have tried to validate them in terms of signal quality and usability, a comprehensive comparison of different dry electrode types from multiple points of view is still missing. The present work proposes a comparison of three different dry electrode types, selected among the main solutions at present, against wet electrodes, taking into account several aspects, both in terms of signal quality and usability. In particular, the three types consisted in gold-coated single pin, multiple pins and solid-gel electrodes. The results confirmed the great standards achieved by dry electrode industry, since it was possible to obtain results comparable to wet electrodes in terms of signals spectra and mental states classification, but at the same time drastically reducing the time of montage and enhancing the comfort. In particular, multiple-pins and solid-gel electrodes overcome gold-coated single-pin-based ones in terms of comfort.

THREE‐DIMENSIONAL RESISTIVITY AND INDUCED‐POLARIZATION MODELING USING BURIED ELECTRODES

Geophysics ◽  
1977 ◽  
Vol 42 (5) ◽  
pp. 1006-1019 ◽  
Author(s):  
Jeffrey J. Daniels
Keyword(s):  
Electrical Properties ◽  
Apparent Resistivity ◽  
Three Dimensional ◽  
Equipotential Surface ◽  
Induced Polarization ◽  
The Body ◽  
Surface Electrode ◽  
Surface Integral ◽  
Drill Holes ◽  
Resistivity Modeling

The three‐dimensional induced‐polarization and resistivity‐modeling problem for buried source and receiver electrodes is solved by using a modified form of Barnett’s surface‐integral technique originally developed for surface‐electrode configurations. Six different buried electrode configurations are considered in this study: three types of hole‐to‐hole configurations, hole‐to‐surface and surface‐to‐hole configurations, and the single hole (bipole‐bipole) configuration. Results show there is no “best” method for all situations encountered in the field. The choice of method depends upon depth of the body, spacing of drill holes, and electrical properties of the body. In hole‐to‐hole measurements, the geometric factor (necessary for the computation of the apparent resistivity) becomes infinitely large or infinitely small whenever the receiving bipole is placed at a depth so that it lies on a zero equipotential surface. This leads to the formation of apparent resistivity anomalies that are extremely sensitive to the presence of the body but that are also complicated and not easily correlated with the position of the body. It is shown that diagnostic and easily interpretable anomalies are obtained by selecting the proper source‐receiver configurations.

scholarly journals Intrinsic properties of the sodium sensor neurons in the rat median preoptic nucleus

2012 ◽  
Vol 303 (8) ◽  
pp. R834-R842 ◽  
Author(s):  
Aurore N. Voisin ◽  
Guy Drolet ◽  
Didier Mouginot
Keyword(s):  
Electrical Properties ◽  
Brain Slices ◽  
Firing Frequency ◽  
The Body ◽  
Neural Population ◽  
Preoptic Nucleus ◽  
Intrinsic Properties ◽  
Median Preoptic Nucleus ◽  
Current Steps

The essential role of the median preoptic nucleus (MnPO) in the integration of chemosensory information associated with the hydromineral state of the rat relies on the presence of a unique population of sodium (Na+) sensor neurons. Little is known about the intrinsic properties of these neurons; therefore, we used whole cell recordings in acute brain slices to determine the electrical fingerprints of this specific neural population of rat MnPO. The data collected from a large sample of neurons (115) indicated that the Na+ sensor neurons represent a majority of the MnPO neurons in situ (83%). These neurons displayed great diversity in both firing patterns induced by transient depolarizing current steps and rectifying properties activated by hyperpolarizing current steps. This diversity of electrical properties was also present in non-Na+ sensor neurons. Subpopulations of Na+ sensor neurons could be distinguished, however, from the non-Na+ sensor neurons. The firing frequency was higher in Na+ sensor neurons, showing irregular spike discharges, and the amplitude of the time-dependent rectification was weaker in the Na+ sensor neurons than in non-Na+ sensor neurons. The diversity among the electrical properties of the MnPO neurons contrasts with the relative function homogeneity (Na+ sensing). However, this diversity might be correlated with a variety of direct synaptic connections linking the MnPO to different brain areas involved in various aspects of the restoration and conservation of the body fluid homeostasis.

Sign in / Sign up

Export Citation Format

Share Document