TY - CONF. T1 - Evaluating plant growth by electrical impedance tomography analysis. AU - Kobata, Kenji. AU - Honda, Satoshi. PY - 2013/1/1. Y1 - 2013/1/1. N2 - This paper shows how to evaluate plant growth by using electrical impedance tomography. Generally electrical impedance tomography (EIT) is used for human body and materials. By using the advantage that plants can be applied electricity inside, we can expect that more information is acquired. First, the problem is solved with a simple model analytically. Secondly, the problem with more precise model is solved numerically. In the previous work we showed how the electrical potential is distributed enough for using EIT.[7] This paper shows that how the inverse problem is solved and the advantage works.. AB - This paper shows how to evaluate plant growth by using electrical impedance tomography. Generally electrical impedance tomography (EIT) is used for human body and materials. By using the advantage that plants can be applied electricity ...

1] Scott-Conner CE, Dawson DL. Operative Anatomy, 3rd ed. Lippincott & Wilkins, Philadelphia; 2009.. [2] Teschner E, Imhoff M. Electrical impedance tomography: The realiza- tion of regional lung monitoring. Dräger Medical GmbH EIT Booklet, Germany, 2011.. [3] Karsten J, Steuber T, Voigt N, Teschner E, Heinze H. Influence of dif- ferent electrode belt positions on electrical impedance tomography imaging of regional ventilation: a prospective observational study. Crit Care 2016;20:3.. [4] Bikker IG, Preis C, Egal M, Bakker J, Gommers D. Electrical impedance tomography measured at two thoracic levels can visualize the ven- tilation distribution changes at the bedside during a decremental positive end-expiratory lung pressure trial. Crit Care 2011;15:R193.. [5] Newell JC, Isaacson D, Cheney M, Saulnier GJ, Gisser DG, Boble JC, Cook RD, Edic PM, Newton CA. In Vivo impedance images using si- nusoidal current patterns. University College London, 1993, Clinical and Physiological Applications of ...

TY - JOUR. T1 - Polynomial Collocation for Handling an Inaccurately Known Measurement Configuration in Electrical Impedance Tomography. AU - Hyvönen, Niina. AU - Kaarnioja, V.. AU - Mustonen, L.. AU - Staboulis, Stratos. PY - 2017. Y1 - 2017. N2 - The objective of electrical impedance tomography is to reconstruct the internal conductivity of a physical body based on measurements of current and potential at a finite number of electrodes attached to its boundary. Although the conductivity is the quantity of main interest in impedance tomography, a real-world measurement configuration includes other unknown parameters as well: The information on the contact resistances, electrode positions, and body shape is almost always incomplete. In this work, the dependence of the electrode measurements on all aforementioned model properties is parametrized via polynomial collocation. The availability of such a parametrization enables efficient simultaneous reconstruction of the conductivity and other ...

TY - JOUR. T1 - Validation study of stroke volume measurement by means of Electrical Impedance Tomography. AU - Janse, A.. AU - Noordegraaf, A. Vonk. AU - Marcus, J. T.. AU - Heethaar, R. M.. AU - Postmus, P. E.. AU - Faes, T. J.C.. AU - de Vries, P. M.J.M.. PY - 1996/12/1. Y1 - 1996/12/1. N2 - ECG-gated Electrical Impedance Tomography (EIT) has been developed to monitor blood volume changes. The aim of this study was to compare stroke volume measurements by EIT with established methods of thermodilution and Magnetic Resonance Imaging (MRI). After right cardiac catheterization, EIT measurements were performed in 26 patients. Regression analysis was used to analyze the relation between the EIT results and stroke volume. From the regression line an equation was derived to estimate stroke volume (in ml) by EIT. In a group of eleven healthy subjects this equation was validated to MRI. A strong correlation was found between EIT and stroke volume measured by the thermodilution method (r = 0.86). The ...

Automatic detection of detached and erroneous electrodes in Electrical Impedance Tomography.POMPES PAR TRANSITIONS MULTIPLES , Automatic detection of detached and erroneous electrodes in Electrical Impedance Tomography.POMPES P... , کتابخانه دیجیتال دانشگاه آزاد اسلامی خوراسگان

The low-frequency complex electrical conductivity in the mHz to kHz range has been shown to enable an improved textural, hydraulic, and biogeochemical characterization of the subsurface using electrical impedance spectroscopy (EIS) methods. Principally, these results can be transferred to the field using electrical impedance tomography (EIT). However, the required accuracy of 1 mrad in the phase measurements is difficult to achieve for a broad frequency bandwidth because of electromagnetic (EM) coupling effects at high frequencies and the lack of inversion schemes that consider the spectral nature of the complex electrical conductivity. Here, we overcome these deficiencies by (i) extending the standard spatial-smoothness constraint in EIT to the frequency dimension, thus enforcing smooth spectral signatures, and (ii) implementing an advanced EM coupling removal procedure using a newly formulated forward electrical model and calibration measurements. Both methodological advances are independently

The FluxMed monitors also have the possibility of incorporating an Electrical Impedance Tomography (EIT) module. The measurement of EIT, using the application of small alternating currents, determine the impedance changes related to ventilation in the thoracic section.. Main Features:. ...

A highly versatile Electrical Impedance Tomography (EIT) system, nicknamed the ScouseTom, has been developed. The system allows control over current amplitude, frequency, number of electrodes, injection protocol and data processing. Current is injected using a Keithley 6221 current source, and voltages are recorded with a 24-bit EEG system with minimum bandwidth of 3.2 kHz. Custom PCBs interface with a PC to control the measurement process, electrode addressing and triggering of external stimuli. The performance of the system was characterised using resistor phantoms to represent human scalp recordings, with an SNR of 77.5 dB, stable across a four hour recording and 20 Hz to 20 kHz. In studies of both haeomorrhage using scalp electrodes, and evoked activity using epicortical electrode mats in rats, it was possible to reconstruct images matching established literature at known areas of onset. Data collected using scalp electrode in humans matched known tissue impedance spectra and was stable over

PURPOSE: Carcinoma in situ is an aggressive form of bladder cancer with a high propensity for invasion if left untreated. On cystoscopy these flat lesions cannot be differentiated from other erythematous, potentially benign areas and they require biopsy for definitive diagnosis. Other methods of detecting carcinoma in situ remain experimental. We assessed the effectiveness of electrical impedance spectroscopy, a method that measures the variation of electrical current flow with frequency through the mucosa, for differentiating various pathological changes in the urothelium. MATERIALS AND METHODS: We obtained 250 impedance measurements immediately after resection in 35 cystectomy specimens using a custom designed probe. Three consecutive readings were recorded per point to assess reproducibility and punch biopsy was done at the measurement site. RESULTS: Changes in the urothelium were classified histologically into 7 subgroups according to the degree of edema and inflammation. Electrical impedance

Background Previous studies have shown statistically significant differences in electrical impedance between various cutaneous lesions. Electrical impedance spectroscopy (EIS) may therefore be able to aid clinicians in differentiating between benign and malignant skin lesions. Objectives The aim of the study was to develop a classification algorithm to distinguish between melanoma and benign lesions of the skin with a sensitivity of at least 98% and a specificity approximately 20 per cent higher than the diagnostic accuracy of dermatologists. Patients/Methods A total of 1300 lesions were collected in a multicentre, prospective, non-randomized clinical trial from 19 centres around Europe. All lesions were excised and subsequently evaluated independently by a panel of three expert dermatopathologists. From the data two classification algorithms were developed and verified. Results For the first classification algorithm, approximately 40% of the data were used for calibration and 60% for testing. ...

Laboratory measurements of the complex electrical conductivity in a broad frequency range (i.e. mHz to kHz) using spectral induced polarization (SIP) measurements have shown great promise to characterize important hydrological properties (e.g. hydraulic conductivity) and biogeochemical processes. However, translating these findings to field applications remains challenging, and significant improvements in spectral electrical impedance tomography (EIT) are still required to obtain images of the complex electrical conductivity with sufficient accuracy in the field. The aim of this study is to present recent improvements in the inversion and processing of broadband field EIT measurements, and to evaluate the accuracy and spectral consistency of the obtained images of the real and imaginary part of the electrical conductivity. In a first case study, time-lapse surface EIT measurements were performed during an infiltration experiment to investigate the spectral complex electrical conductivity as a function

bioelectrical impedance analysis answers are found in the Tabers Medical Dictionary powered by Unbound Medicine. Available for iPhone, iPad, Android, and Web.

Ultrasound modulated electrical impedance tomography (UMEIT) is a novel hybrid imaging technique, which utilizes coupling between electric and acoustic modalities. Based on the forward solver along different current directions, an instrumental electrode configuration is proposed for 3D UMEIT. The pr …

The design and performance of the active complex electrode (ACE1) electrical impedance tomography system for single-ended phasic voltage measurements are presented. The design of the hardware and calibration procedures allows for reconstruction of conductivity and permittivity images. Phase measurement is achieved with the ACE1 active electrode circuit which measures the amplitude and phase of the voltage and the applied current at the location at which current is injected into the body. An evaluation of the system performance under typical operating conditions includes details of demodulation and calibration and an in-depth look at insightful metrics, such as signal-to-noise ratio variations during a single current pattern. Static and dynamic images of conductivity and permittivity are presented from ACE1 data collected on tank phantoms and human subjects to illustrate the systems utility.

Public examination of a doctoral dissertation in the field of physics. Doctoral candidate: M.Sc. Antti Nissinen Date and venue: 3.6.2011 at 12 noon, L22, Snellmania, Kuopio campus. ABSTRACT In electrical impedance tomography (EIT), electrodes are attached on the boundary of the object and currents are injected into the object. The voltages are measured using the same electrodes and the conductivity of the object is reconstructed based on the measured voltages. The reconstruction problem is a non-linear ill-posed inverse problem, i.e. the problem is highly sensitive to measurement and approximation errors. The effect of the measurement errors can be reduced by using an accurate measurement system and by accurate modeling of the statistics of the error. Approximation errors are due to an approximative computational model used in the inverse computations. In practical applications, an adequately accurate mathematical model cannot often be used due to limited computational resources, and therefore a ...

Chest electrical impedance tomography examination, data analysis, terminology, clinical use and recommendations: consensus statement of the TRanslational EIT developmeNt stuDy group ...

In this work we study localized electric potentials that have an arbitrarily high energy on some given subset of a domain and low energy on another. We show that such potentials exist for general $L^\infty_+$-conductivities in almost arbitrarily shaped subregions of a domain, as long as these regions are connected to the boundary and a unique continuation principle is satisfied. From this we deduce a simple, but new, theoretical identifiability result for the famous Calderón problem with partial data. We also show how to construct such potentials numerically and use a connection with the factorization method to derive a new non-iterative algorithm for the detection of inclusions in electrical impedance tomography.

In this paper, we study a fast approximate inference method based on expectation propagation for exploring the posterior probability distribution arising from the Bayesian formulation of nonlinear inverse problems. It is capable of efficiently delivering reliable estimates of the posterior mean and covariance, thereby providing an inverse solution together with quantified uncertainties. Some theoretical properties of the iterative algorithm are discussed, and the efficient implementation for an important class of problems of projection type is described. The method is illustrated with one typical nonlinear inverse problem, electrical impedance tomography with complete electrode model, under sparsity constraints. Numerical results for real experimental data are presented, and compared with that by Markov chain Monte Carlo. The results indicate that the method is accurate and computationally very efficient. ...

We study flexible and proper smoothness priors for Bayesian statistical inverse problems by using Whittle-Matérn Gaussian random fields. We review earlier results on finite-difference approximations of certain Whittle-Matérn random field in $\mathbb{R}^2$. Then we derive finite-element method approximations and show that the discrete approximations can be expressed as solutions of sparse stochastic matrix equations. Such equations are known to be computationally efficient and useful in inverse problems with a large number of unknowns. |br|    The presented construction of Whittle-Matérn correlation functions allows both isotropic or anisotropic priors with adjustable parameters in correlation length and variance. These parameters can be used, for example, to model spatially varying structural information of unknowns. |br|    As numerical examples, we apply the developed priors to two-dimensional electrical impedance tomography

A T Tidswell, JS Wyatt, RH Bayford, DS Holder; Electrical Impedance Tomography of Neonatal Brain Activity. Clin Sci (Lond) 1 July 2002; 103 (s47): 63P. doi: https://doi.org/10.1042/cs103063P. Download citation file:. ...

Soleimani, M. and Estrela, P., 2009. Miniaturised electrical impedance spectroscopy tomography (EITS) for single cell imaging: A simulation study. In: First Bio-Sensing Technology Conference, 2009-11-10 - 2009-11-12.. ...

PURPOSE: To investigate the functional role that the zinc e-box binding homeobox 1 (ZEB1) gene, which underlies the genetic basis of posterior polymorphous corneal dystrophy 3 (PPCD3), plays in corneal endothelial cell proliferation, apoptosis, migration, and barrier function. METHODS: A human corneal endothelial cell line (HCEnC-21T) was transfected with siRNA targeting ZEB1 mRNA. Cell proliferation, apoptosis, migration, and barrier assays were performed: Cell proliferation was assessed with cell counting using a hemocytometer; cell apoptosis, induced by either ultraviolet C (UVC) radiation or doxorubicin treatment, was quantified by measuring cleaved caspase 3 (cCASP3) protein levels; and cell migration and barrier function were monitored with electric cell-substrate impedance sensing (ECIS ...

Blood-brain barrier (BBB) disruption and neuroinflammation are considered key mechanisms of pathogenic Escherichia coli invasion of the brain. However, the specific molecules involved in meningitic E. coli-induced BBB breakdown and neuroinflammatory response remain unclear. Our previous RNA-sequencing data from human brain microvascular endothelial cells (hBMECs) revealed two important host factors: platelet-derived growth factor-B (PDGF-B) and intercellular adhesion molecule-1 (ICAM-1), which were significantly upregulated in hBMECs after meningitic E. coli infection. Whether and how PDGF-B and ICAM-1 contribute to the development of E. coli meningitis are still unclear. The western blot, real-time PCR, enzyme-linked immunosorbent assay, immunohistochemistry, and immunofluorescence were applied to verify the significant induction of PDGF-B and ICAM-1 by meningitic E. coli in vivo and in vitro. Evans blue assay and electric cell-substrate impedance sensing assay were combined to identify the effects of

In biomedical engineering, bioimpedance is a term used to describe the response of a living organism to an externally applied electric current. It is a measure of the oppostion to the flow of that electric current through the tissues, the opposite of electrical conductivity. The measurement of the bioimpedance (or bioelectrical impedance) of the humans and animals has proved useful as a non-invasive method for measuring such things as blood flow (often referred to as bioimpedance plethysmography) and body composition ( known as bioelectrical impedance analysis or simply BIA). In bioimpedance plethysmography, the measure is sometimes based on pulsatile blood volume changes in the aorta. Bioimpedance is relevant to the development of devices to measure cardiac output and circulating blood volume. Electrical conductivity can vary as a result of breathing. Because of this and other sources of variability, the reliability of bioimpedance for obtaining accurate data has been called into question. ...

A preliminary investigation in our laboratory has demonstrated the advantage of using 4-compartment modeling to assess body composition in SCI adults. In comparing body composition analyses techniques in 20 individuals with SCI, we found Total Error to be 8.0% with Dual X-ray Absorptiometry, 8.4% with hydrodensitometry, 11.5% with bioelectrical impedance analysis, and 21.8% with standard skinfold equations when compared to 4-compartment modeling, the currently accepted gold standard for body composition assessment. To date there is no gold standard for the determination of body composition in SCI individuals ...

A preliminary investigation in our laboratory has demonstrated the advantage of using 4-compartment modeling to assess body composition in SCI adults. In comparing body composition analyses techniques in 20 individuals with SCI, we found Total Error to be 8.0% with Dual X-ray Absorptiometry, 8.4% with hydrodensitometry, 11.5% with bioelectrical impedance analysis, and 21.8% with standard skinfold equations when compared to 4-compartment modeling, the currently accepted gold standard for body composition assessment. To date there is no gold standard for the determination of body composition in SCI individuals ...

TY - JOUR. T1 - Relating rapid chloride transport parameters of concretes to microstructural features extracted from electrical impedance. AU - Neithalath, Narayanan. AU - Jain, Jitendra. PY - 2010/7/1. Y1 - 2010/7/1. N2 - The rapid chloride transport parameters such as the rapid chloride permeability (RCP) and non-steady state migration coefficient are related to the material microstructural parameters in this paper. Electrical impedance spectroscopy and associated equivalent circuit modeling are used to extract the microstructural features of the plain concrete as well as concretes modified with varying amounts of Class F fly ash or silica fume. A methodology is developed in this paper that utilizes the ratios of RCP values and the ratios of effective conductivities to pore solution conductivities of plain and modified concretes, to quantify the relative influence of pore solution conductivity and pore structure on the RCP values. The resistance attributable to the connected pores is extracted ...

MOBICON-REMOTE ELECTRONIC SDN BHD - Precision Meter/LCR Meter/Impedance Analyzer Keysight, Mobicon-Remote Electronic Sdn Bhd is an electronic components distributor company. Our main office is located in Petaling Jaya (PJ), Selangor, Malaysia.

Electrical resistivity tomography (ERT) is a geophysical technique for imaging sub-surface variation of resistivity value from 2D/3D electrical resistivity survey made at surface or borehole. The properties that affect the resistivity of soil or bedrock include porosity, water content, composition (clay mineral and metal content), the salinity of the pore water, and grain size distribution. During resistivity surveys, artificial-ly-generated, near direct current (DC) between current electrodes are injected into the ground and electric potential between two or more pairs of receiver electrodes are measured simultaneously. 2D/3D Inverse modeling is then performed to obtain a sub-surface model of the surveyed site. Therefore, the resistivity tomography survey is ideally suited to investigate the lateral and vertical change of subsurface resistivity and also delineate three-dimensional resistivity anomalies.. Depending on the clients need, SDI uses state of the art multi-channel resistivity ...

In this paper, we present a microscale impedance-based technique for detecting different levels of blood plasma coagulation triggered by tissue factor thromboplastin. Impedance-based detection relies on measuring changes in the ac impedance between two electrodes due to the formation of favorably insoluble fibrin after treated with thromboplastin. Both gold and carbon parallel electrodes were tested and the optimum operating frequency for most sensitive coagulation detection was investigated. Micro fabricated gold electrodes could be used to detect the impedance difference between different levels of plasmas and the result was compared with optical measurement. A peculiar conductance maximum occurs at the optimal frequency for carbon electrodes and is a sensitive indicator of blood coagulation. Our optimized small electrode sensors are ideal for point-of-care applications.. Copyright © 2005 by ASME ...

TY - JOUR. T1 - Current distribution effects in AC impedance spectroscopy of electroceramic point contact and thin film model electrodes. AU - Nielsen, Jimmi. AU - Jacobsen, Torben. PY - 2010. Y1 - 2010. N2 - The Finite-Element-Method (FEM) was used for the simulations of the effect of a changing current distribution during AC impedance spectrum recording on electroceramic point contact and thin film model electrodes. For pure electronic conducting point contact electrodes the transition from the primary current distribution to the DC current distribution restricted to the Three-Phase-Boundary (TPB) zone introduces an error in the determination of the reaction resistance, Rreac = Z(freq. → 0) − Z(freq. → ∞). The error is estimated for different width of the effective TPB zone and a rule of thumb regarding its significance is provided. The associated characteristic impedance spectrum shape change is simulated and its origin discussed. Furthermore, the characteristic shape of impedance ...

Electrical impedance spectroscopy is a non-destructive method for analysing the structure and properties on different materials and objects.

A new electrochemical model has been carefully established to explain the carbonation behavior of cement mortar, and the model has been validated by the experimental results. In fact, it is shown by this study that the electrochemical impedance behavior of mortars varies in the process of carbonation. With the cement/sand ratio reduced, the carbonation rate reveals more remarkable. The carbonation process can be quantitatively accessed by a parameter, which can be obtained by means of the electrochemical impedance spectroscopy (EIS)-based electrochemical model. It has been found that the parameter is a function of carbonation depth and of carbonation time. Thereby, prediction of carbonation depth can be achieved.

0050] The control unit 40 is additionally connected to an impedance determination unit 56. The impedance determination unit 56 is connected to a power source I and a voltage measuring unit U, which in turn are connected to the terminals for the annular electrode 24 and the tip electrode 22. In this way, the direct current source I can constantly deliver voltage pulses by way of the tip electrode 22 and the annular electrode 24, and the voltage measuring unit U can measure the respective voltage that is released. On the basis of these values, the impedance determination unit 56 can determine a particular impedance value. An impedance value determined in this way depends on a variety of influencing variables. For example, a fracture of an electric conductor in the electrode line 20 would manifest itself in a very high impedance value. When the electrode line 20 is intact, the impedance to be measured between the electrode poles 22 and 24 also depends on the blood volume in the right ventricle of a ...

This study has shown that mean cervical tissue resistivity obtained with 5 mm and 9 mm EIS probes differs significantly in the frequency range 4-819 kHz. This difference was most marked at lower electrical frequencies, with the magnitude of tissue impedance values being twice as high with the small, compared to the larger, probe. However, at higher frequencies the resistivity values obtained were similar for both probes. Short-term intra-observer variability of cervical resistivity measurement did not differ between the two probes. We noted a close correlation between our in vivo observations and the predicted cervical resistivity using a FE cervical tissue computer model. Additionally, this model suggested that the fraction of injected current passing through the cervical stroma would be higher at all frequencies for the 9 mm compared to the 5 mm probe, and would be a maximum at about 100 kHz when approximately 90% stromal penetration was attained with the larger probe, compared to about 70% ...

This is the first study using BIA to demonstrate an association between suidoku and body composition and to identify factors associated with suidoku. Many problems related to a lack of objectivity have been reported for Kampo medicine. Lo et al. showed low rates of agreement in tongue diagnoses, particularly differences in judgment about tongue color, and reported the usefulness of an automated tongue diagnosis system [6]. They also stated that tongue diagnosis is often biased by the diagnostic skill level, experience and color perception. Furthermore, Ishida et al. reported that a skin moisture deficiency might be an indicator of blood deficiency [12]. Although the establishment of objective indices is desired, reports based on objective evaluations of suidoku are still lacking. Although there have been some reports about factors associated with suidoku, they analyzed subjective symptoms. Because no studies have been published that have attempted to objectively quantify suidoku [17, 18], this ...

Alterations in the health of muscles can be evaluated through the use of electrical impedance myography (EIM). To date, however, nearly all work in this field has relied upon the measurement of muscle at rest. To provide an insight into the contractile mechanisms of healthy and disease muscle, we evaluated the alterations in the spectroscopic impedance behavior of muscle during the active process of muscle contraction. The gastrocnemii from a total of 13 mice were studied (five wild type, four muscular dystrophy animals, and four amyotrophic lateral sclerosis animals). Muscle contraction was induced via monophasic current pulse stimulation of the sciatic nerve. Simultaneously, multisine EIM (1 kHz to 1 MHz) and force measurements of the muscle were performed. Stimulation was applied at three different rates to produce mild, moderate, and strong contractions. We identified changes in both single and multifrequency data, as assessed by the Cole impedance model parameters. The processes of ...

Abstract: In Electrical Impedance Tomography (EIT) one wants to image the conductivity distribution of a body from current and voltage measurements carried out on its boundary. In this paper we consider the underlying mathematical model, the inverse conductivity problem, in two dimensions and under the realistic assumption that only a part of the boundary is accessible to measurements. In this framework our data are modeled as a partial Neumann-to-Dirichlet map (ND map). We compare this data to the full-boundary ND map and prove that the error depends linearly on the size of the missing part of the boundary. The same linear dependence is further proved for the difference of the reconstructed conductivities -- from partial and full boundary data. The reconstruction is based on a truncated and linearized D-bar method. Auxiliary results include an extrapolation method to obtain the full-boundary data from the measured one, an approximation of the complex geometrical optics solutions computed ...

TY - JOUR. T1 - A physical interpretation of impedance at conducting polymer/electrolyte junctions. AU - Stavrinidou, Eleni. AU - Sessolo, Michele. AU - Winther Jensen, Bjorn. AU - Sanaur, Sébastien. AU - Malliaras, George G.. PY - 2014/1. Y1 - 2014/1. N2 - We monitor the process of dedoping in a planar junction between an electrolyte and a conducting polymer using electrochemical impedance spectroscopy performed during moving front measurements. The impedance spectra are consistent with an equivalent circuit of a time varying resistor in parallel with a capacitor. We show that the resistor corresponds to ion transport in the dedoped region of the film, and can be quantitatively described using ion density and drift mobility obtained from the moving front measurements. The capacitor, on the other hand, does not depend on time and is associated with charge separation at the moving front. This work offers a physical description of the impedance of conducting polymer/electrolyte interfaces based ...

As previously mentioned, electrical conductivity and permittivity vary among biological tissue types and depend on their free ion content.[2][3][8] Further factors affecting conductivity include temperature and other physiological factors, e.g. the respiratory cycle between in- and expiration when lung tissue becomes more conductive due to lower content of insulating air within its alveoli. After positioning surface electrodes through adhesive electrodes, an electrode belt or a conductive electrode vest around the body part of interest, alternating currents of typically a few milliamperes at a frequency of 10-100 kHz will be applied across two or more drive electrodes. The remaining electrodes will be used to measure the resulting voltage. The procedure will then be repeated for numerous stimulation patterns, e.g. successive pairs of adjacent electrodes until an entire circle has been completed and image reconstruction can be carried out and displayed by a digital workstation that incorporates ...

An automated test system and procedure is proposed, designed to enable systematic testing of electrical impedance tomography (EIT) devices. The system is designed to calculate reliable, repeatable and accurate performance figures of merit of an EIT system using a saline phantom and an industrial robot arm. Applications of the test system are to compare EIT devices against requirements, or to help optimize a device for its operating parameters. A test methodology and sample test results are presented to illustrate its use. The system is used to compare image quality and contrast detection for a range of stimulation and measurement patterns, and results show the best images when the pair of current injection electrodes is spaced between 45 and 170 degrees on a tank. Finally, we propose a classification of the object detection errors, which can facilitate comparison of EIT instrument specifications.. ...

Biological tissues show complex bioelectrical impedance which depends on the tissue compositions, tissue structure, tissue health and signal frequency. As the tissue composition, structure and health are significantly changed during boiling, there will be a significant change in tissue electrical properties in the boiled tissues. Therefore, impedance variation with tissue boiling can be correlated with the tissue health status and it can be suitably used for noninvasive assessment of tissue health either in food technology or in the medical treatment of a burnt patient. In this direction the impedance variation in banana stem tissues is studied in unboiled and boiled conditions and the responses of the complex bio-impedance are analyzed over a wide range of frequencies. Results demonstrate that the bioelectrical impedance of the plants tissues drastically reduce due to the boiling effect and the alpha-dispersion and beta-dispersion in the bioimpedance found for unboiled tissue disappears in the ...

Breast cancer screening is an evolving area as there is still need of finding the ideal screening modality that fit the community demand of mass screening. The aims are to evaluate the validation and feasibility of EIT against gold standard mammography and to determine women pain perception towards both imaging methods. Women underwent screening mammography were selected for EIT imaging. The pain score were taken after each imaging session. Two independent raters were chosen to interpret image findings of EIT. 164 women were successfully selected for the study. 48.17 of subjects were classified as normal (group 1) with no significant findings (BIRADS 1); and 51.83 of subjects were classified as abnormal (group 2) with significant findings of either benign or suspicious of malignancy (BIRADS2). EIT sensitivity and specificity against screening mammography for rater 1 were 69.41 and 63.29, whereas for rater 2 were 55.29 and 56.96 respectively. The reliability for each rater were found to range ...

83 [35] K. Banach, M. D. Halbach, P. Hu, J. Hescheler, and U. Egert, Development of electrical activity in cardiac myocyte aggregates de rived from mouse embryonic stem cells, Am J Physiol Heart Circ Physiol vol. 284, pp. H2114-23, 2003. [36] J. Hescheler, Y. Duan, M. Tang, and H. Linag, Investigation on spontaneous electrical activity of murine embryonic heart using microelectrode arrays, Acta Physiologica Sinica vol. 58, pp. 65-70, 2006. [37] J. Malmivuo and R. Plonsey, Bioelectromagnetism Principles and Applications of Bioelectric and Biomagnetic Fields New York, NY: Oxford University Press, 1995. [38] A. Adler, R. Amyot, R. Guardo, J. H. T. Bates, and Y. Berthiaume, Monitoring changes in lung air and liquid volumes with electrical impedance tomography, J Appl Physiol vol. 83, pp. 1762-1767, 1997. [39] I. Frerichs, J. Hinz, P. Herrmann, G. Wei sser, G. Hahn, T. Dudykevych, M. Quintel, and G. Hellige, Detection of local lung air content by electrical impedance tomography compared with ...

Transthoracic electrical impedance (or admittance) cardiography is a simple technique for the non-invasive and continuous monitoring of stroke volume or cardiac output by detecting the electrical impedance of a thorax which is roughly assumed to be a

2012 (English)In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 112, no 12, 2128-2128 p.Article in journal, Letter (Refereed) Published ...

Submarine groundwater discharge (SGD) is an important conduit that links terrestrial and marine environments. SGD conveys both water and water-borne constituents into coastal waters, where these inflows may impact near-shore ecosystem health and sustainability. Multichannel electrical resistivity techniques have proven to be a powerful tool to examine scales and dynamics of SGD and SGD forcings. However, there are uncertainties both in data aquisition and data processing that must be addressed to maximize the effectiveness of this tool in estuarine or marine environments. These issues most often relate to discerning subtle nuances in the flow of electricity through variably saturated media that can also be highly conductive (i.e., seawater). Three contrasting field sites were examined for this study to assess the effectiveness of electrical resistivity techniques in varying coastal settings by comparing resistivity data to direct salinity and resistivity observations, quantifying changes in lithology

Over 200,000 men are diagnosed each year with prostate cancer. Surgical removal of the prostate represents a treatment option chosen by 140,000 men annually in which the primary objective is to eradicate all prostate cancer cells within the body. Cancer cells identified on the margins of the surgically removed prostate suggest that cancer cells were left within the body. These positive surgical margins (PSMs) are indications for disease recurrence and suggest noxious adjuvant or salvage therapies. Unfortunately, no clinical protocols are routinely used to intraoperatively assess surgical margin status during prostate surgery. Instead, margins are evaluated through pathological assessment of the prostate following radical prostatectomy (RP), when it is too late to provide additional surgical intervention.. Significantly different electrical property signatures have been observed between benign and malignant prostate tissues, and we hypothesize that gauging these properties intraoperatively has ...

The East Asian Journal on Applied Mathematics (EAJAM) aims at promoting study and research in Applied Mathematics in East Asia. It is the editorial policy of EAJAM to accept refereed papers in all active areas of Applied Mathematics and related Mathematical Sciences. Novel applications of Mathematics in real situations are especially welcome. Substantial survey papers on topics of exceptional interest will also be published occasionally.

The International Steering Committee of Electrical Impedance Tomography is pleased to announce that the 12th International Conference in Electrical Impedance Tomography (EIT 2011) will take place at the Department of electronic & Electrical Engineering, University of Bath, on 4-6 May 2011. The conference venue is the University of Bath, which is 15 minutes bus journey from the world heritage city of Bath. To find and book your accomodation please visit City of Bath accomodation Website. As usual, the conference will focus on medical applications of Electrical Impedance Tomography, Magnetic Induction Tomography, and Magnetic Resonance Electrical Impedance Tomography. ...

TY - GEN. T1 - Noise analysis of MREIT at 3T and 11T field strength. AU - Sadleir, R. J.. AU - Grant, S. C.. AU - Zhang, S. U.. AU - Oh, S. H.. AU - Lee, B. I.. AU - Pyo, H. C.. AU - Park, C. J.. AU - Woo, E. J.. AU - Lee, S. Y.. AU - Seo, J. K.. AU - Kwon, O.. PY - 2005. Y1 - 2005. N2 - In Magnetic Resonance Electrical Impedance Tomography (MREIT), we measure the induced magnetic flux density inside an imaging object subject to an external injection current. The magnetic flux density is contaminated with noise and this ultimately limits the quality of reconstructed conductivity and current density images. By using two methods to analyze amounts of noise in 3T and 11T MREIT systems, we found that a carefully designed MREIT study will be able to reduce the noise level below 0.1 nT.. AB - In Magnetic Resonance Electrical Impedance Tomography (MREIT), we measure the induced magnetic flux density inside an imaging object subject to an external injection current. The magnetic flux density is ...

Respiratory Sinus Arrhythmia, the variation in the heart rate synchronized with the breathing cycle, forms an interconnection between cardiac-related and respiratory-related signals. It can be used by itself for diagnostic purposes, or by exploiting the redundancies it creates, for example by extracting respiratory rate from an electrocardiogram (ECG). To perform quantitative analysis and patient specific modeling, however, simultaneous information about ventilation as well as cardiac activity needs to be recorded and analyzed. The recent advent of medically approved Electrical Impedance Tomography (EIT) devices capable of recording up to 50 frames per second facilitates the application of this technology. This paper presents the automated selection of a cardiac-related signal from EIT data and quantitative analysis of this signal. It is demonstrated that beat-to-beat intervals can be extracted with a median absolute error below 20 ms. A comparison between ECG and EIT data shows a variation in ...

Previous work by us and others had suggested that cervical electrical impedance spectroscopy (EIS) may be predictive of the outcome of induced labour. We sought to determine which probe configuration of the EIS device is predictive of the outcome of induced labour and compare this to digital assessment by the Bishop score. In a prospective cohort of 205 women admitted for induction of labour, we used four probes of diameter 3, 6, 9 and 12 mm connected to an impedance meter to measure cervical resistivity (CR) in Ohm.meters at 14 electrical frequencies and compared their values to digital assessment of the cervix by the Bishop score for the prediction of the outcome of induced labour. We tested the association of labour characteristics and outcomes with CR and Bishop score by stepwise multilinear regression analyses, and the accuracy of prediction of categorical clinical outcomes by analysis of the area under the curves (AUC) of derived Receiver Operator Characteristic (ROC) curves. Of the four CR probe

Looking for online definition of Resistance measurement in the Medical Dictionary? Resistance measurement explanation free. What is Resistance measurement? Meaning of Resistance measurement medical term. What does Resistance measurement mean?

Magnetic resonance electrical impedance tomography (MREIT) is a technique that produces images of conductivity in tissues and phantoms. In this technique, electrical currents are applied to an object and the resulting magnetic flux density is measured using magnetic resonance imaging (MRI) and the conductivity distribution is reconstructed using these MRI data. Currently, the technique is used in research environments, primarily studying phantoms and animals. In order to translate MREIT to clinical applications, strict safety standards need to be established, especially for safe current limits. However, there are currently no standards for safe current limits specific to MREIT. Until such standards are established, human MREIT applications need to conform to existing electrical safety standards in medical instrumentation, such as IEC601. This protocol limits patient auxiliary currents to 100 µA for low frequencies. However, published MREIT studies have utilized currents 10-400 times larger than ...

Impedance cardiography (ICG) is a noninvasive technology measuring total electrical conductivity of the thorax and its changes in time to process continuously a number of cardiodynamic parameters, such as Stroke Volume, SV, Heart Rate, HR, Cardiac Output, CO, Ventricular Ejection Time, VET, Pre-ejection Period and used to detect the impedance changes caused by a high-frequency, low magnitude current flowing through the thorax between additional two pairs of electrodes located outside of the measured segment. The sensing electrodes also detect the ECG signal, which is used as a timing clock of the system. Impedance cardiography (ICG), also referred to as electrical impedance plethysmography (EIP) or Thoracic Electrical Bioimpedance (TEB) has been researched since the 1940s. NASA helped develop the technology in the 1960s. The use of impedance cardiography in psychophysiological research was pioneered by the publication of an article by Miller and Horvath in 1978. Subsequently, the recommendations ...

In this paper, the behavior of the salicylate anion-selective electrode was studied using the electrochemical impedance spectroscopy technique. Considering the diagram of the charge transfer resistance and -logarithm of the double layer capacitance versus -logarithm of the concentration, linear range concentration increased to 1.0×10^{-8}-1.0×10^{-1} M and 1.0×10^{-9}-1.0×10^{-1} M, respectively. Among the other characteristics of this study, it can be pointed out a wide pH range of 4.0-10.0. Then one-impedance for one-concentration method was used to measure the salicylate ion at the linear range of 1.0×10^{-8}-1.0×10^{-1} M. Finally, the impedance spectra of this electrode were simulated in which the obtained results of this simulation indicate proximity of experimental and simulation data.

Apparatus is provided for detecting the presence of a high impedance arcing fault on an electrical circuit, particularly a high voltage power line. Detection of a high impedance fault is realized by monitoring the high frequency components of the alternating current in the circuit, and evaluating the high frequency components of each cycle of the alternating current using a microcomputer operating in accordance with a program of instructions, to determine the occurrence of a significant increase in magnitude of the high frequency components, and then to determine whether the increase exists for a prescribed period of time and follows a prescribed pattern. The high frequency components are monitored using a current-to-voltage transducer coupled to the electrical circuit, bandpass filters coupled to the transducer, and an analog-to-digital converter providing digitized samples of the filtered transducer output voltage signal.

A software toolbox for low-frequency conductivity and current density imaging using MRI is now available from http://iirc.khu.ac.kr/software.html. This MR-based conductivity imaging (MRCI) toolbox includes Matlab functions for image reconstructions in magnetic resonance electrical impedance tomography (MREIT), diffusion tensor MREIT (DTMREIT), conductivity... Read more ...

p,This paper describes the development of a low-cost, miniaturized, multiplexed, and connected platform for dielectric impedance spectroscopy (DIS), designed for in situ measurements and adapted to wireless network architectures. The platform has been tested and used as a DIS sensor node on ZigBee mesh and was able to interface up to three DIS sensors at the same time and relay the information through the network for data analysis and storage. The system is built from low-cost commercial microelectronics components, performs dielectric spectroscopy ranging from 5 kHz to 100 kHz, and benefits from an on-the-fly calibration system that makes sensor calibration easy. The paper describes the microelectronics design, the Nyquist impedance response, the measurement sensitivity and accuracy, and the testing of the platform for in situ dielectric impedance spectroscopy applications pertaining to fertilizer sensing, water quality sensing, and touch sensing. ,/p,. ...

TY - JOUR. T1 - Electrical resistivity in SmCoIn5 under high pressure. AU - Koeda, Masahito. AU - Hedo, Masato. AU - Fujiwara, Tetsuya. AU - Uwatoko, Yoshiya. AU - Sadamasa, Tomoko. AU - Inada, Yoshihiko. N1 - Copyright: Copyright 2018 Elsevier B.V., All rights reserved.. PY - 2007. Y1 - 2007. N2 - SmCoIn5 crystallizes in the tetragonal HoCoGa5 type structure. This type of crystal structure have attracted much attention because new heavy-fermion superconductivity with very high superconducting transition temperature Tc=18.5 K was discovered in PuCoGa5. It is expected that Sm has a similar ground state to Pu compounds. Thus we have measured the electrical resistivity on a single crystal of SmCoIn5 using a cubic anvil pressure cell at temperature 2-300 K under high pressure from 2 to 8 GPa. The value of TN that was 11.9 K at ambient pressure in SmCoIn5 increased to 13.2 K at P=2 GPa,. Above 2 GPa, It decreased monotonously with increasing pressure and was 12.6 K at 8 GPa. It may be thought that ...

The increase in conductance, which accompanies the spike in the presence of sea water, is followed by a decrease to below the resting level, here designated as the initial after-impedance, which lasts 3 msec. and is 3 per cent as great as the increase. Treatment with cevadine usually obliterates the latter but leaves the former essentially unaltered. In addition, the alkaloid gives rise to periodic conductance increases followed by a prolonged, exponentially decaying elevated conductance (the negativity after-impedance) which correspond closely to potential oscillations and to the negative after-potential. These are also only a few per cent of the major conductance change. Veratridine causes a conductance increase which lasts longer and which also conforms closely with earlier after-potential results.. Preliminary calculations indicate that the negativity after-impedance and the negative after-potential may be due to the subsidence of an elevated chloride permeability. However, no ...

We provide our patients with the most comprehensive body composition testing on the market! • Only takes 17 seconds • Understand your weight • Monitor your fat, lean muscle mass and total body water • Set your goals and track your progress • Receive an easy to read analysis that informs you on where your health stands Experience a cutting-edge bioelectrical impedance analysis with the seca mBCA. Our noninvasive assessment provides an in-depth analysis measuring fat mass, fat-free mass, total body water, intracellular water, extracellular water, and skeletal muscle mass in a rapid 17 seconds. Distinguish between muscle gain and fat loss and understand the real health benefits even when your weight remains the same.

In a method of monitoring pulmonary edema in a human being, an electrical current is injected between a first electrode located in or around a heart and a housing of a medical device implanted in a chest region. A voltage potential is measured between a second electrode in a superior vena cava and a third electrode in the superior vena cava, where the voltage potential is created by the electrical current. Pulmonary edema is assessed based on an impedance value calculated from the electrical current and the voltage potential and a stored edema threshold impedance value.

Electrical resistivity tomography (ERT) and transient electromagnetic (TEM) surveys were done in Luikonlahti tailings impoundment area, Eastern Finland. Purpose of the measurements were to find the structure of the tailings impoundment area and possible seepage areas. Totally 5 ERT profiles and 4 TEM profiles were measured in the tailings area. ERT and TEM measurements revealed clearly the structure of tailings impoundment. Results of the both methods agreed and coincide with the drilling results.

United States Geological Survey, Pacific Science Center,United States Geological Survey, Western Fisheries Research Center,United States Geological Survey, Washington Water Science Center,Nisqually National Wildlife Refuge,University of Washington,Western Washington University. Chief Scientists: Eric Grossman, USGS, Pete Swarzenski, USGS, Steve Rubin. Sediment and water sampling, electrical resistivity mapping, groundwater, monitoring, habitat characterization data of field activity A-6-09-PS in Nisqually Delta, WA from 08/16/2009 to 08/22/2009, ,http://walrus.wr.usgs.gov/infobank/a/a609ps/html/a-6-09-ps.meta.html, ...

This work reports a novel deltamethrin (DM) sensor able to detect nano-molar concentrations in ethanol solutions. The sensing layer consists of a thin film, obtained via a layer-by-layer technique, from alternate adsorption of poly(allylamine chloride) (PAH) and poly[1-[4-(3-carboxy-4-hydroxyphenylazo)-benzenesulfonamide)-1,2-ethanediyl]sodium salt] (PAZO) onto a solid support with interdigitaded gold electrodes. The sensor response, obtained from impedance spectroscopy measurements, was revealed to be linear with respect to the real part of impedance, taken at 100 Hz, when plotted as a function of the logarithm of deltamethrin molar concentrations in the micro- to nano-molar range. Sensor sensitivity was of 41.1 ± 0.7 kΩ per decade of concentration for an immersion time above 2 min and the reproducibility is approximately 2% in a binary solution of ethanol and deltamethrin. The main insight of this work concerns to DM detection limits as the sensor revealed to be able to detect concentrations below

BACKGROUND: Skeletal muscle wasting is related to muscle dysfunction, exercise intolerance, and increased mortality risk in patients with COPD. STUDY OBJECTIVES: The aims of this study were to investigate the effects of whole-body exercise training on body composition in normal-weight patients with COPD, and to study the relationship between changes in body composition and functional capacity. SETTING AND PARTICIPANTS: Fifty patients with COPD (FEV(1), 39% of predicted [SD, 16]) admitted to the pulmonary rehabilitation center at Hornerheide, and 36 healthy age-matched control subjects (for baseline comparison) were included. INTERVENTIONS: Patients participated in a standardized inpatient exercise training program consisting of daily submaximal cycle ergometry, treadmill walking, weight training, and gymnastics during 8 weeks. MEASUREMENTS: Fat-free mass (FFM) was measured by bioelectrical impedance analysis. None of the patients met the criteria for nutritional supplementation (body mass index ...

TY - CONF. T1 - Improvement of the electrical capacitance tomography imaging using total variation regularisation. AU - Soleimani, Manuchehr. AU - Lionheart, WRB. PY - 2004. Y1 - 2004. M3 - Paper. SP - 543. EP - 546. T2 - Proceedings of the XII International Conference on Electrical Bio-Impedance and Electrical Impedance Tomography. Y2 - 20 June 2004 through 24 June 2004. ER - ...

Purpose: The influence of female sex hormones on body fluid regulation and metabolism homeostasis has been widely studied. However, it remains unclear whether hormone fluctuations throughout the menstrual cycle (MC) and with oral contraceptive (OC) use affect body composition (BC). Thus, the aim of this study was to investigate BC over the MC and OC cycle in well-trained females. Methods: A total of 52 eumenorrheic and 33 monophasic OC-taking well-trained females participated in this study. Several BC variables were measured through bioelectrical impedance analysis 3 times in the eumenorrheic group (early follicular phase, late follicular phase, and midluteal phase) and on 2 occasions in the OC group (withdrawal phase and active pill phase). Results: Mixed linear model tests reported no significant differences in the BC variables (body weight, body mass index, basal metabolism, fat mass, fat-free mass, and total body water) between the MC phases or between the OC phases (P , .05 for all ...

Objective: This study aimed to compare the various anthropometric and body composition parameters based on the ethnicity and the absence or presence of menarche.Design: A cross-sectional study with incomplete sampling, using the subject as the evaluation unit.Subjects: the final sample of 550 subjects was composed of 122 Japanese and 179 Caucasian premenarcheal adolescents, and 72 Japanese and 177 Caucasian postmenarcheal adolescents.Methods: the variables of body composition were measured through the following methods: bioelectrical impedance analysis, near-infrared interactance (NIR), Slaughter cutaneous skinfold equations and body mass index. Weight, height and sitting height were also evaluated.Results: the Japanese pre- and postmenarcheal girls presented lower weight and height values when compared with the Caucasian girls. in general, the Japanese premenarcheal girls presented less fat and fat-free mass than the premenarcheal Caucasian girls. This fact was demonstrated through NIR results. ...

Road Responses to Vibration Tests. The dynamic properties of road pavements are measured with equipment using small vibrational forces (< 25 kg), after verification of the condition of elastic linearity in pavement behavior. With minor modifications, this equipment is suitable for wave propagation, attenuation and impedance measurements. Approximate simple methods, verified in practice, have been employed to determine the attenuation in, and Young's moduli of, the various road layers, while a seven-parameter mechanical model was devised to explain the experimental impedance curves. A Fourier analysis was applied to the results of impedance measurements made over a wide frequency range, to predict road deflections caused by an impulse function of any shape, and the treatment was verified experimentally. Results from wave propagation, attenuation and impedance measurements were combined to evaluate road deflections under a moving wheel load.

TY - JOUR. T1 - Electrodeless Measurements of the Effective Resistivity of the Human Torso and Head by Magnetic Induction. AU - Tarjan, Peter P.. AU - McFee, Richard. N1 - Copyright: Copyright 2015 Elsevier B.V., All rights reserved.. PY - 1968/10. Y1 - 1968/10. N2 - A magnetically coupled impedance measuring instrument has been developed for determining an effective electrical resistivity of human subjects without electrodes. The instrument operates at 100 kHz. The value obtained represents an average of the resistivity of tissue near the coils. The human torso and the head were found to act, in regard to this measurement, as if they had homogeneous resistivities of about 425 and 350 Ωcm respectively. Thoracic resistivity fluctuations due to respiration (tidal volume) and pulsatile blood flow were about 4 percent (breathing) and 1 percent (blood pumping). These measurements were taken when the subjects were lying face down with their hearts directly over the coil system. The records resemble ...

Recovery of hydrocarbon gas in micro-Darcy rock is now becoming more common-place for gas producers. As part of the reservoir characterization associated with these systems, it is required to understand parameters such as the total porosity and permeability of the system, but also the initial water saturation and the effective gas permeability at this connate water saturation. This is still under the realm of what is termed routine core analysis, but in these tight formations it is imperative to understand that these tests are actually very non-routine by nature. Current work presents a case study of core analysis that was run on plugs from a tight gas producing formation, and illustrates some of the pitfalls and corrections associated with measurements of this low permeability rock. The case study combines low field NMR measurements with core flooding measurements of porosity and permeability. Cores are initially tested at their connate water saturations: NMR measures the initial water ...

It is unclear whether adiposity leads to changes in movement behaviors, and there is a lack of compositional analyses of longitudinal data which focus on these associations. Using a compositional approach, this study aimed to examine the associations between baseline adiposity and 7-year changes in physical activity (PA) and sedentary behavior (SB) among elderly women. We also explored the longitudinal associations between change in adiposity and change in movement-behavior composition. This longitudinal study included 176 older women (mean baseline age 62.8 (4.1) years) from Central Europe. Movement behavior was assessed by accelerometers and adiposity was measured by bioelectrical impedance analysis at baseline and follow-up. A set of multivariate least-squares regression analyses was used to examine the associations of baseline adiposity and longitudinal changes in adiposity as explanatory variables with longitudinal changes in a 3-part movement-behavior composition consisting of SB, light PA (LPA)

Quality Laptop digital Ultrasound Machine 10 LCD usb connector multi-frequency probes available for sale - buy cheap Laptop digital Ultrasound Machine 10 LCD usb connector multi-frequency probes available from Laptop Ultrasound Scanner manufacturers & Laptop Ultrasound Scanner supplier of China (103901392).

INTRODUCTION Electrical Impedance Tomography (EIT)is an emerging clinical imaging technique. Functional EIT by EvokedResponse (fEITER) was developed at the University of Manchester asa high-speed, functional brain imaging device for use at thebedside. This 32-electrode EIT system applies an injectionfrequency of 10kHz and captures data using a 10ms temporalresolution. This thesis reports on the first volunteer and patienttrials undertaken using fEITER for the following conditions: (a)flashing visual sequence - 14 awake volunteers; (b) a voluntaryValsalva manoeuvre (VM) - 15 awake volunteers and (c) during theinduction of anaesthesia - 16 elective surgical patients.AIMS Theresearch presented in this thesis was undertaken to differentiatebetween noise and physiological changes in raw fEITER datasignals.METHODS SNR was determined for fEITER. Raw fEITER signalswere pre-processed to reduce noise and dominant trends beforemultiple comparisons between reference and stimulus data wereundertaken. Histograms and

BACKGROUND: Delayed ventricular arrhythmias during acute myocardial ischemia (1B arrhythmias) are associated with an increase in tissue impedance and are most likely sustained in a thin subepicardial layer. OBJECTIVE: The goal of this study was to test the hypothesis that heterogeneous uncoupling between depolarized midmyocardium and surviving subepicardium results in heterogeneous refractoriness in the latter, providing the reentry substrate after a premature beat. METHODS: A 3-dimensional bidomain slab was constructed comprising a normal subepicardial layer coupled to a slightly depolarized (-80 to -60 mV) but inexcitable midmyocardium. Experimentally measured tissue impedance served as input for the model. Four stages of heterogeneous uncoupling between the 2 layers were simulated, each corresponding to an experimental ischemic impedance value. Effective refractory periods (ERP), conduction velocities, and inducibility of reentry were examined. RESULTS: Heterogeneous uncoupling resulted in

THE electric resistance of Fe-Si alloys was measured in a longitudinal magnetic field at various temperatures. The specimens were annealed at 1000° C. for one hotir and re-annealed at 850° for one hour after setting them on the measuring apparatus.

The acid corrosion inhibition process of armco iron in hydrochloric acid 1 M HCl by a modified polyphosphate derivatives of guanidine and urea copolymer (PGUC) has been investigated using electrochemical impedance spectroscopy (EIS). The effect of a thermal treatment of the copolymer on the corrosion behaviour was studied. Data obtained from Electrochemical Impedance Spectroscopy (EIS) show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPE) has been used. The PGUC derivatives have also been used as biocides in aqueous environments and the bacterial killing efficiencies have been determined.

IASS-IACM 2008 Session: New Advances in Topology Optimization -- Session Organizers: Glaucio H. PAULINO (UIUC), Emilio SILVA (University of Sao Paulo) -- Keynote Lecture: Topology optimization with adaptive mesh refinement by Eric DE STURLER (Virginia Tech), Glaucio H. PAULINO, Shun WANG (University of Illinois at Urbana-Champaign) -- Strategies for computational efficiency in continuum structural topology optimization of sparse 3D systems by Colby C. SWAN , Salam F. RAHMATALLA (University of Iowa) -- Wachpress elements for topology optimization by Cameron TALISCHI , Glaucio H. PAULINO, Chau H. LE (University of Illinois at Urbana-Champaign) -- Topology optimization technique considering both static and dynamic characteristics of the structures by S. J. LEE , J. E. BAE (Gyeongsang National University) -- Keynote Lecture: Topology optimization method utilizing iterative solvers with subspace recycling applied to high-resolution electrical impedance tomography by Luis Augusto Motta MELLO ...

SGLT2-inhibitors are potent antihyperglycemic drugs for patients with type 2 diabetes and have been shown to reduce body weight. However, it is unclear which body compartments are reduced and to what extent. In this longitudinal observational study, we analyzed the body composition of 27 outpatients with type 2 diabetes mellitus during the first week and up to 6 months after initiation of treatment with SGLT2-inhibitors (n = 18 empagliflozin, n = 9 dapagliflozin) using bioimpedance spectroscopy (BCM, Fresenius). Fluid status of hypertensive patients taking medication with hydrochlorothiazide (n = 14) and healthy persons (n = 16) were analyzed for comparison. At 6 months, HbA1c decreased by 0.8% (IQR 2.3; 0.4), body weight and BMI by 2.6 kg (1.5; 9.3) and 0.9 kg/m2 (0.4; 3.3), respectively. Bioimpedance spectroscopy revealed significant decrease in adipose tissue mass and fat tissue index while lean tissue parameters remained stable. Overhydration (OH) and extracellular water (ECW) decreased by − 0.5 L

This BSL PRO lesson describes hardware and software setup of the BSL System to record ECG, Impedance (Z0), and Derivative Impedance (dZ/dt), and measure relative differences in Cardiac Output and Stroke Volume using a noninvasive bioimpedance technique.. The Lesson Procedure for BSL 4.0.1 or above includes an extensively updated physiological introduction that covers Cardiac Output as a Function of Stroke Volume and Heart Rate, Cardiac Output as Related to Mean Arterial Pressure and Peripheral Resistance, How to Determine Cardiac Output, Principles of Impedance Cardiography (ICG), and Ideas for eliciting cardiovascular responses through physical maneuvers and psychological tasks.. Suggested reading: Methodological Guidelines for Impedance Cardiography ...

Introduction: Although complex pulmonary arterial remolding characterizes pulmonary hypertension (PH), the vascular mechanics has been evaluated by the static pressure-flow relationship (resistance, R) ignoring dynamic mechanical properties (compliance, C). We therefore evaluated pulmonary arterial input impedance (Z) capable of identifying not only resistance but also compliance in monocrotaline (MCT) and Sugen/Hypoxia (SuHx) PH models.. Methods: In 6 weeks Sprague-Dawley rats, we induced PH by the subcutaneous injection of MCT (60 mg/kg) or Sugen5416 (20 mg/kg) with 3 weeks hypoxia. In anesthetized PH rats, we measured pulmonary artery flow (PAF) and pressure (PAP) at 1000 Hz for 107.52 seconds under irregular pacing. We Fourier transformed both PAF and PAP to derive ensembled power spectra and crosspower spectra and taking their ratio yielded Z. We fitted the 2-element Windkessel model to Z and estimated R and C.. Results: MCT and SuHx significantly increased mean PAP (Control: 19.4±2.0, ...

Nursing interventions rationale monitor circulation, airway, and breathing ; stabilizing the tube, or have a high specificity:39 a. On cardiac mri; thick late gadolinium enhancement on t1 indicates cellular death and/or scarring. Morrison ml etal. By echocardiography, the inter-atrial intervals are constant. The patient likely has pseudoclaudication from hip osteoarthritis or spinal stenosis b. Arterial claudication is likely to be aware that other people tell them to rest. 163 c. Maintenance of av valve abnormalities generally include stenosis, atresia, and heart rate, and monitor for hematologic, renal, hepatic, ototoxic, and other more rare pregnancy complications, or nonreassuring results of preg- nancy is limited. 4,6,7 however, situs ambiguous is not a lack of health and illness, what success or failure begins when the birth institution and fetal heart rate is between the child will actually swallow loose chips of lead-based paint in older children. B. Lead impedance changes with each ...

A pattern of decreasing resistance was found in nonsurvivor patients, reflecting an increased distribution volume. Higher values of net fluid balance in nonsurvivors are due to higher amounts of intravenous fluid therapy used in more severe trauma patients. TBI may help evaluate body fluid compartments in trauma patients, and may also be helpful in identifying high-risk patients who would benefit from more aggressive therapeutic interventions. ...

Looking for impedance plethysmograph? Find out information about impedance plethysmograph. An instrument for measuring changes in the size of a part of the body by measuring changes in the amount of blood in that part Explanation of impedance plethysmograph

Finni T, Saakslahti A, Laukkanen A, Pesola A, Sipila S. A family based tailored counselling to increase non-exercise physical activity in adults with a sedentary job and physical activity in their young children: design and methods of a year-long randomized controlled trial. BMC Public Health 2011;11:944-2458-11-944 ...

TY - JOUR. T1 - Uric acid distribution volume calculated by kinetic modeling and extracellular volume predicted by bioimpedance method. AU - Shinzato, Toru. AU - Nakai, Shigeru. AU - Ito, Takahito. AU - Shibata, Kazuhiko. AU - Matsuoka, Teppei. AU - Kato, Shinya. AU - Aoki, Takeshi. AU - Masakane, Ikuto. AU - Hayashi, Hiroki. AU - Tsuboi, Naotake. AU - Hasegawa, Midori. AU - Inaguma, Daijo. AU - Yuzawa, Yukio. AU - Ookawara, Susumu. N1 - Publisher Copyright: © The Author(s) 2020.. PY - 2020/11/1. Y1 - 2020/11/1. N2 - Background: Several reports indicate that extracellular volume predicted by bioimpedance analysis method is associated with hydration status of hemodialysis patients. Theory: Fundamentally, uric acid does not cross cell membranes by simple diffusion, either by facilitated diffusion or by active transport. In addition, uric acid cannot move through cell membranes in most tissues other than those involved in uric acid excretion. These facts support the interpretation that uric acid ...

Electrochemical impedance spectroscopy (EIS) is applied to detect pathogenic E. coli O157:H7 bacteria via a label free immunoassay-based detection method. Polyclonal anti-E.coli antibodies (PAb) are immobilized onto gold electrodes following two different strategies, via chemical bond formation between antibody amino groups and a carboxylic acid containing self-assembled molecular monolayer (SAM) and alternatively by linking a biotinylated anti-E. coli to Neutravidin on a mixed-SAM. Impedance spectra for sensors of both designs for increasing concentrations of E. coli are recorded in phosphate buffered saline (PBS). The Nyquist plots can be modeled with a Randle equivalent circuit, identifying the charge transfer resistance RCT as the relevant concentration dependent parameter. Sensors fabricated from both designs are able to detect very low concentration of E. coli with limits of detection as low as 10-100 cfu/ml. The influence of the different immobilization protocols on the sensor performance ...

We report on a biological artifact that is unknown in the EEG-literature, presumably due to its invisibility in the unfiltered raw EEG. On account of its probable electrogenesis, we discuss Arterial Pulse Impedance Artifact (APIA). One may also call it a virtual artifact because it only becomes manifest as the averaged mean value of power spectra from consecutive 2s epochs across a total length of 5 min (150 epochs). APIA has a cardiac origin, mediated by the superficial head arteries. The arterial pulse induces rhythmic changes in the electrical impedance between the cortical generator inside the skull and the recording electrode that is outside. APIA will only show up in the EEG if an electrode is fixed very close to the artery. APIA vanishes upon minimal shifting of the corresponding electrode. Detectability in the FFT-spectrogram is due to an amplification effect. The only possibility to avoid this artifact consists in excluding the APIA-prone spectral components below 2.0Hz from any further

AB - La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSCF) solid oxide fuel cell cathodes were poisoned by Cr at different temperatures and polarization conditions with a Cr-Fe alloy as the interconnect. Cr induced degradation was analysed by electrochemical impedance spectroscopy (EIS) focusing on the electrochemical resistance (R chem ) that reflects the cathode electrochemical properties. It was found that R chem increased more with increasing temperatures. However cathodic polarization exhibited a synergistic effect with the temperature, which accelerated the LSCF cathode degradation at 800 °C while lowering the degree of degradation at 900 °C. By correlating complementary micro- and nano-scale microstructure characterization with the impedance analysis, the degradation mechanisms were investigated. A new Cr incorporation mechanism involving preferential formation of nanometre size Fe-Co-Cr-O spinel particles within the cathode up to the cathode/electrolyte interface was found to be responsible for ...