Imaging methods that result in sharp images of objects located on a chosen plane and blurred images located above or below the plane.
The resistance to the flow of either alternating or direct electrical current.
Recording changes in electrical impedance between electrodes placed on opposite sides of a part of the body, as a measure of volume changes in the path of the current. (Stedman, 25th ed)
Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)
Electric conductors through which electric currents enter or leave a medium, whether it be an electrolytic solution, solid, molten mass, gas, or vacuum.
Devices or objects in various imaging techniques used to visualize or enhance visualization by simulating conditions encountered in the procedure. Phantoms are used very often in procedures employing or measuring x-irradiation or radioactive material to evaluate performance. Phantoms often have properties similar to human tissue. Water demonstrates absorbing properties similar to normal tissue, hence water-filled phantoms are used to map radiation levels. Phantoms are used also as teaching aids to simulate real conditions with x-ray or ultrasonic machines. (From Iturralde, Dictionary and Handbook of Nuclear Medicine and Clinical Imaging, 1990)
A technique of measuring the dielectric properties of materials, which vary over a range of frequencies depending on the physical properties of the material. The technique involves measuring, over a range of frequencies, ELECTRICAL IMPEDANCE and phase shift of an electric field as it passes through the material.
The relative amounts of various components in the body, such as percentage of body fat.
Fluids composed mainly of water found within the body.
A type of impedance plethysmography in which bioelectrical impedance is measured between electrodes positioned around the neck and around the lower thorax. It is used principally to calculate stroke volume and cardiac volume, but it is also related to myocardial contractility, thoracic fluid content, and circulation to the extremities.
The technique that deals with the measurement of the size, weight, and proportions of the human or other primate body.
The use of specifically placed small electrodes to deliver electrical impulses across the SKIN to relieve PAIN. It is used less frequently to produce ANESTHESIA.
Surgically placed electric conductors through which ELECTRIC STIMULATION is delivered to or electrical activity is recorded from a specific point inside the body.
Application of electric current in treatment without the generation of perceptible heat. It includes electric stimulation of nerves or muscles, passage of current into the body, or use of interrupted current of low intensity to raise the threshold of the skin to pain.
Therapy for MOVEMENT DISORDERS, especially PARKINSON DISEASE, that applies electricity via stereotactic implantation of ELECTRODES in specific areas of the BRAIN such as the THALAMUS. The electrodes are attached to a neurostimulator placed subcutaneously.
Use of electric potential or currents to elicit biological responses.
Lens-shaped structure on the inner aspect of the INTERNAL CAPSULE. The SUBTHALAMIC NUCLEUS and pathways traversing this region are concerned with the integration of somatic motor function.
A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.
Endoscopic examination, therapy or surgery of the bronchi.
The outer covering of the calvaria. It is composed of several layers: SKIN; subcutaneous connective tissue; the occipitofrontal muscle which includes the tendinous galea aponeurotica; loose connective tissue; and the pericranium (the PERIOSTEUM of the SKULL).
The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.
A gland in males that surrounds the neck of the URINARY BLADDER and the URETHRA. It secretes a substance that liquefies coagulated semen. It is situated in the pelvic cavity behind the lower part of the PUBIC SYMPHYSIS, above the deep layer of the triangular ligament, and rests upon the RECTUM.
Complete or partial surgical removal of the prostate. Three primary approaches are commonly employed: suprapubic - removal through an incision above the pubis and through the urinary bladder; retropubic - as for suprapubic but without entering the urinary bladder; and transurethral (TRANSURETHRAL RESECTION OF PROSTATE).
Tumors or cancer of the PROSTATE.
The quantity of volume or surface area of a CELL NUCLEUS.

An intrinsic oscillation in interneurons of the rat lateral geniculate nucleus. (1/2193)

By using the whole cell patch recording technique in vitro, we examined the voltage-dependent firing patterns of 69 interneurons in the rat dorsal lateral geniculate nucleus (LGN). When held at a hyperpolarized membrane potential, all interneurons responded with a burst of action potentials. In 48 interneurons, larger current pulses produced a bursting oscillation. When relatively depolarized, some interneurons produced a tonic train of action potentials in response to a depolarizing current pulse. However, most interneurons produced only oscillations, regardless of polarization level. The oscillation was insensitive to the bath application of a combination of blockers to excitatory and inhibitory synaptic transmission, including 30 microM 6,7-dinitroquinoxaline-2,3-dione, 100 microM (+/-)-2-amino-5-phosphonopentanoic acid, 20 microM bicuculline, and 2 mM saclofen, suggesting an intrinsic event. The frequency of the oscillation in interneurons was dependent on the intensity of the injection current. Increasing current intensity increased the oscillation frequency. The maximal frequency of the oscillation was 5-15 Hz for most cells, with some ambiguity caused by the difficulty of precisely defining a transition from oscillatory to regular firing behavior. In contrast, the interneuron oscillation was little affected by preceding depolarizing and hyperpolarizing pulses. In addition to being elicited by depolarizing current injections, the oscillation could also be initiated by electrical stimulation of the optic tract when the interneurons were held at a depolarized membrane potential. This suggests that interneurons may be recruited into thalamic oscillations by synaptic inputs. These results indicate that interneurons may play a larger role in thalamic oscillations than was previously thought.  (+info)

Utilization of bioelectrical impedance to predict carcass composition of Holstein steers at 3, 6, 9, and 12 months of age. (2/2193)

The objective of this experiment was to study the usefulness of bioelectrical impedance analysis (BIA) in determining soft tissue composition (STC) and carcass fat-free mass (CFFM) of Holstein steers at different ages. Growth data and prediction of STC and CFFM were determined for four groups of Holstein steers: 12 of 3 mo, 12 of 6 mo, 15 of 9 mo, and 16 of 12 mo of age. Average weight for animals at 3, 6, 9, and 12 mo were 96.6, 204.7, 354.1, and 465.9 kg, respectively. Average fat content of carcass soft tissue at 3, 6, 9, and 12 mo were 2.6, 9.8, 18.2, and 24.6%, respectively. Average protein content of the carcass soft tissue was 20.7% at 3 mo, 20% at 6 mo, 18.30% at 9 mo, and 16.9% at 12 mo of age. Feed and water were withheld for 20 h before the BIA was applied. Steers were sedated and forced to recumbency in a lateral position on their right sides over a nonconductive surface. Two electrodes were placed on each limb of the right side (metatarsal and metacarpal regions on back and front foot, respectively). Resistance (Rs) and reactance (Xc) were obtained by attaching four terminals to the electrodes. Impedance and other predictors such as Vol1 (L/Rs), Vol2 (L2/(RS2+Xc2).5, Vol3 (geometrical animal volume), L (2 x height + body length), and L2 were calculated from Rs and Xc, and body measurements and were used to generate prediction equations for CFFM and carcass soft tissue composition. Carcass fat-free mass was predicted accurately for all age groups and the pooled data (r2 = .99 at 3 mo, .99 at 6 mo, .97 at 9 mo, .77 at 12 mo, and .98 for the pooled data). Correlation coefficients between impedance readings and CFFM and carcass composition were calculated. Carcass CFFM and kilograms of H2O for the pooled data (across age groups) were both correlated highly to Vol1 (.97), Vol2 (.95), L (.97), and L2 (.97).  (+info)

In vitro analog of operant conditioning in aplysia. I. Contingent reinforcement modifies the functional dynamics of an identified neuron. (3/2193)

Previously, an analog of operant conditioning in Aplysia was developed using the rhythmic motor activity in the isolated buccal ganglia. This analog expressed a key feature of operant conditioning, namely a selective enhancement in the occurrence of a designated motor pattern by contingent reinforcement. Different motor patterns generated by the buccal central pattern generator were induced by monotonic stimulation of a peripheral nerve (i.e., n.2,3). Phasic stimulation of the esophageal nerve (E n.) was used as an analog of reinforcement. The present study investigated the neuronal mechanisms associated with the genesis of different motor patterns and their modifications by contingent reinforcement. The genesis of different motor patterns was related to changes in the functional states of the pre-motor neuron B51. During rhythmic activity, B51 dynamically switched between inactive and active states. Bursting activity in B51 was associated with, and predicted, characteristic features of a specific motor pattern (i.e., pattern I). Contingent reinforcement of pattern I modified the dynamical properties of B51 by decreasing its resting conductance and threshold for eliciting plateau potentials and thus increased the occurrences of pattern I-related activity in B51. These modifications were not observed in preparations that received either noncontingent reinforcement (i.e., yoke control) or no reinforcement (i.e., control). These results suggest that a contingent reinforcement paradigm can regulate the dynamics of neuronal activity that is centrally programmed by the intrinsic cellular properties of neurons.  (+info)

Comparative cytotoxicity of ionic and non-ionic radiocontrast agents on MDCK cell monolayers in vitro. (4/2193)

BACKGROUND: Intravascular radiocontrast agents may cause acute renal failure, particularly in patients with pre-existing renal insufficiency. Direct cytotoxic effects of radiocontrast agents on renal tubular cells may contribute to the pathogenesis of radiocontrast-induced nephropathy. METHODS: We analysed the cytotoxicity of the ionic radiocontrast agents diatrizoate (monomeric) and ioxaglate (dimeric), as well as of the non-ionic radiocontrast agents iohexol (monomeric) and iodixanol (dimeric) on the renal epithelial Madin Darby Canine Kidney (MDCK) cell line grown on permeable supports. The toxicity assays assessed cell viability, transmonolayer resistance and inulin permeability between the apical and basal cell culture compartment. In addition, the distribution of the tight-junction-associated membrane proteins ZO-1 and occludin was analysed using immunofluorescence microscopy. RESULTS: In all assays the high osmolal ionic compound diatrizoate had significant cytotoxic effects that included the partial redistribution of the tight-junction-associated membrane proteins into a cytoplasmic compartment. To a lesser extent this redistribution also occurred with the dimeric ionic compound ioxaglate, but not with the non-ionic radiocontrast agents. With regards to cell viability, transmonolayer resistance and inulin permeability the radiocontrast agents with reduced osmolality were significantly less toxic than diatrizoate, independent of their ionic strength. CONCLUSIONS: Physicochemical factors contribute to the cytotoxicity of radiocontrast agents in vitro. The redistribution of tight-junction-associated membrane proteins by the ionic radiocontrast agents corresponds with the loss of the barrier function of the epithelial cell monolayer, which is a major pathophysiological mechanism in acute renal failure. The radiocontrast agents with reduced osmolality are less cytotoxic than diatrizoate, independent of their ionicity. Hyperosmolality appears to be a more important determinant of the cytotoxicity of diatrizoate than ionic strength.  (+info)

Fluid state and blood pressure control in patients treated with long and short haemodialysis. (5/2193)

BACKGROUND: Patients treated at the haemodialysis (HD) centre in Tassin, France have been reported to have superior survival and blood pressure (BP) control. This control has been ascribed to maintenance of an adequate fluid state, antihypertensive drugs being required in < 5% of the patients, although it could not be excluded that a high dose of HD regarding removal of uraemic toxins might also have been of value. METHODS: The aim of the study was to assess the fluid state and BP in normotensive patients on long HD (8 h) in Tassin (group TN) using bioimpedance to measure extracellular volume (ECV), ultrasound for determining the inferior vena cava diameter (IVCD), and 'on-line' monitoring of the change in blood volume (BV), and to compare them with normotensive (group SN) and hypertensive (group SH) patients on short HD (3-5 h) at centres in Sweden. ECV was normalized (ECVn) by arbitrarily setting the median ECV (in % of body weight) in SN patients at 100% for each gender, recalculating the individual values and combining the results for male and female patients in each group. RESULTS: The dose of HD (Kt/V urea) was higher for TN patients than for Swedish patients who had a similar Kt/V, whether hypertensive or not. SH patients had significantly higher ECVn and IVCD than TN and SN patients. TN and SN patients did not differ significantly regarding ECVn and IVCD before and after HD. However, in a subgroup of eight TN patients, ECVn was below the range of that in SH and SN patients, due to obesity with a high body mass index. Another subgroup of 14 TN patients had a higher ECVn than most of the SN patients and also higher than the median ECVn in the SH group, without any difference in body mass index, but they were nevertheless normotensive. The fall in BV was greater in SN than in TN patients, presumably due to a higher ultrafiltration rate in SN patients. However, SH patients had a smaller change in BV than SN patients, presumably because their state of overhydration facilitated refilling of BV from the interstitial fluid. CONCLUSIONS: Normotension can be achieved independently of the duration and dose (Kt/V urea) of HD, if the control of post-dialysis ECV is adequate. However, this is more difficult to achieve with short than with more prolonged HD during which the ultrafiltration rate is lower, BV changes are smaller and intradialysis symptoms less frequent. The results in the subgroup of patients with high ECVn at Tassin suggest that normotension may also be achieved in patients with fluid overload provided that the dialysis time is long enough to ensure more efficient removal of one or more vasoactive factors that cause or contribute to hypertension.  (+info)

Bioelectrical impedance plethysmographic analysis of body composition in critically injured and healthy subjects. (6/2193)

BACKGROUND: Determination of body composition during critical illness is complex because of various patient-related and technical factors. Bioelectrical impedance is a promising technique for the analysis of body composition; however, its clinical utility in critically injured patients is unknown. OBJECTIVE: The purpose of this study was to compare bioelectrical impedance with metabolic activity in healthy and critically injured patients. If bioelectrical impedance accurately determines body composition during critical illness, the slope between body-composition variables and oxygen consumption would be the same in critically injured and healthy subjects. DESIGN: There is a strong linear relation between body composition and metabolic activity. In the present study, body composition (fat-free mass and body cell mass) was determined by using bioelectrical impedance and resting metabolic activity (metabolic rate and oxygen consumption) by using gas exchange analysis in a group of healthy and critically injured subjects. The relation between these variables was compared by using linear regression to a similar relation established by hydrostatic weighing in a large historical control group. RESULTS: The slope of the line relating fat-free mass to resting metabolic rate was the same in the healthy and critically ill groups (P = 0.62) and each was similar to the slope of the line for the control group. However, in 37% of the critically injured group, overhydration contributed to an increase in fat-free mass, disturbing the relation with resting metabolic rate. The slope of the line relating body cell mass to oxygen consumption in our healthy and critically ill groups was almost identical. CONCLUSION: These results support the use of bioelectrical impedance to determine body cell mass in healthy and critically ill subjects.  (+info)

Relative influences of sex, race, environment, and HIV infection on body composition in adults. (7/2193)

BACKGROUND: The factors that control body composition in disease are uncertain. OBJECTIVE: We planned to compare the relative influences of HIV infection, sex, race, and environment on body composition. METHODS: We analyzed results of body composition studies performed by bioelectrical impedance analysis in 1415 adults from 2 cohorts: white and African American men and women from the United States, and African men and women (279 HIV-infected and 1136 control). The effects of sex and HIV infection on weight, body cell mass, and fat-free mass were analyzed by using both unadjusted and age-, weight-, and height-adjusted data. RESULTS: Control men weighed more and had more body cell mass and fat-free mass than did control women, although control women had more fat. The strongest correlates with body composition were height and weight, followed by sex. HIV infection, age, environment, and race. Control men and women weighed more and had more body cell mass, fat-free mass, and fat than did HIV-infected men. However, differences in body composition between HIV-infected and control groups were strongly influenced by sex. Of the differences in weight between HIV-infected and uninfected subjects, fat-free mass accounted for 51% in men but only 18% in women, in whom the remainder was fat. Sex effects were similar in African and American groups. CONCLUSIONS: Sex has a marked effect on the changes in body composition during HIV infection, with women losing disproportionately more fat than men. Sex-related differences in body composition were narrower in the HIV-infected groups. Race and environment had smaller effects than sex and HIV infection.  (+info)

The isoflavone genistein inhibits internalization of enteric bacteria by cultured Caco-2 and HT-29 enterocytes. (8/2193)

The dietary isoflavone genistein is the focus of much research involving its role as a potential therapeutic agent in a variety of diseases, including cancer and heart disease. However, there is recent evidence that dietary genistein may also have an inhibitory effect on extraintestinal invasion of enteric bacteria. To study the effects of genistein on bacterial adherence and internalization by confluent enterocytes, Caco-2 and HT-29 enterocytes (cultivated for 15-18 d and 21-24 d, respectively) were pretreated for 1 h with 0, 30, 100, or 300 micromol/L genistein, followed by 1-h incubation with pure cultures of Listeria monocytogenes, Salmonella typhimurium, Proteus mirabilis, or Escherichia coli. Pretreatment of Caco-2 and HT-29 enterocytes with genistein inhibited bacterial internalization in a dose-dependent manner (r = 0.60-0.79). Compared to untreated enterocytes, 1-h pretreatment with 300 micromol/L genistein was generally associated with decreased bacterial internalization (P < 0. 05) without a corresponding decrease in bacterial adherence. Using Caco-2 cell cultures, decreased bacterial internalization was associated with increased integrity of enterocyte tight junctions [measured by increased transepithelial electrical resistance (TEER)], with alterations in the distribution of enterocyte perijunctional actin filaments (visualized by fluorescein-labeled phalloidin), and with abrogation of the decreased TEER associated with S. typhimurium and E. coli incubation with the enterocytes (P < 0.01). Thus, genistein was associated with inhibition of enterocyte internalization of enteric bacteria by a mechanism that might be related to the integrity of the enterocyte tight junctions, suggesting that genistein might function as a barrier-sustaining agent, inhibiting extraintestinal invasion of enteric bacteria.  (+info)

Purpose: To analyze the association between body fluid changes evaluated by bioelectrical impedance vector analysis and dilution techniques over a competitive season in athletes. Methods: A total of 58 athletes of both sexes (men: age 18.7 [4.0] y and women: age 19.2 [6.0] y) engaging in different sports were evaluated at the beginning (pre) and 6 months after (post) the competitive season. Deuterium dilution and bromide dilution were used as the criterion methods to assess total body water (TBW) and extracellular water (ECW), respectively; intracellular water (ICW) was calculated as TBW-ECW. Bioelectrical resistance and reactance were obtained with a phase-sensitive 50-kHz bioelectrical impedance analysis device; bioelectrical impedance vector analysis was applied. Dual-energy X-ray absorptiometry was used to assess fat mass and fat-free mass. The athletes were empirically classified considering TBW change (pre-post, increase or decrease) according to sex. Results: Significant mean vector ...
TY - JOUR. T1 - Bioelectrical impedance analysis. T2 - Implications for clinical practice. AU - Jacobs, Danny O.. PY - 1997/12/1. Y1 - 1997/12/1. N2 - Bioelectrical impedance analysis (BIA) has received significant attention as a means of studying body composition and the relationship of changes in the bodys conductive and other electrical properties to changes in body water or its distribution. The application of this technology to the care of patients with nutritional and metabolic disorders is presently under investigation. In this review, a broad overview of recent literature is provided, after the background and rationale for BIA and factors affecting the accuracy of measurements are reviewed.. AB - Bioelectrical impedance analysis (BIA) has received significant attention as a means of studying body composition and the relationship of changes in the bodys conductive and other electrical properties to changes in body water or its distribution. The application of this technology to the care ...
Drug and bioactive molecule screening based on a bioelectrical impedance cell culture platform Sakthivel Ramasamy,1 Devasier Bennet,1 Sanghyo Kim1,2 1Department of Bionanotechnology, Gachon University, Gyeonggi-Do, Republic of Korea; 2Graduate Gachon Medical Research Institute, Gil Medical Center, Incheon, Republic of Korea Abstract: This review will present a brief discussion on the recent advancements of bioelectrical impedance cell-based biosensors, especially the electric cell-substrate impedance sensing (ECIS) system for screening of various bioactive molecules. The different technical integrations of various chip types, working principles, measurement systems, and applications for drug targeting of molecules in cells are highlighted in this paper. Screening of bioactive molecules based on electric cell-substrate impedance sensing is a trial-and-error process toward the development of therapeutically active agents for drug discovery and therapeutics. In general, bioactive molecule
Bioelectrical Impedance Analysis (BIA) and Body Composition Analyse. Bioelectrical Impedance Analysis (BIA) and Body Composition Analyse.
Bioelectrical Impedance Analysis (BIA) and Body Composition Analyse. Bioelectrical Impedance Analysis (BIA) and Body Composition Analyse.
This thesis work covered the fabrication and characterisation of impedance sensors for biological applications aiming in particular to the cytotoxicity monitoring of cultured cells exposed to different kind of chemical compounds and drugs and to the identification of different types of biological tissue (fat, muscles, nerves) using a sensor fabricated on the tip of a commercially available needle during peripheral nerve block procedures. Gold impedance electrodes have been successfully fabricated for impedance measurement on cells cultured on the electrode surface which was modified with the fabrication of gold nanopillars. These nanostructures have a height of 60nm or 100nm and they have highly ordered layout as they are fabricated through the e-beam technique. The fabrication of the threedimensional structures on the interdigitated electrodes was supposed to improve the sensitivity of the ECIS (electric cell-substrate impedance sensing) measurement while monitoring the cytotoxicity effects of ...
Arias L.R., Carla A.P., Yang L.: Real-Time Electrical Impedance Detection of Cellular Activities of Oral Cancer Cells. Biosensors and Bioelectronics 25(10), 2010, 2225-2231. DOI: https://doi.org/10.1016/j.bios.2010.02.029 Arndt S., Seebach J., Psathaki K., Galla H.J., Wegener J.: Bioelectrical Impedance Assay to Monitor Changes in Cell Shape during Apoptosis. Biosensors and Bioelectronics 19(6), 2004, 583-594. DOI: https://doi.org/10.1016/S0956-5663(03)00269-0 Bagnaninchi P.O., Drummond N.: Real-Time Label-Free Monitoring of Adipose-Derived Stem Cell Differentiation with Electric Cell-Substrate Impedance Sensing. Proceedings of the National Academy of Sciences of the United States of America 108(16), 2011, 6462-6467. DOI: https://doi.org/10.1073/pnas.1018260108 Giaever I., Keese C.R.: A Morphological Biosensor for Mammalian Cells. Nature 366(6455), 1993, 591-592. Hong J., Kandasamy K., Marimuthu M., Choi M.S., Kim S.: Electrical Cell-Substrate Impedance Sensing as a Non-Invasive Tool for Cancer ...
Background: Appendicular skeletal muscle (or lean) mass (ALM) estimated by dual-energy X-ray absorptiometry (DXA) is considered to be a preferred method for sarcopenia studies. However, DXA is expensive, has limited portability, and requires radiation exposure. Bioelectrical impedance analysis (BIA) is inexpensive, easy to use, and portable; thus BIA might be useful in sarcopenia investigations. However, a large variety of models have been commercially supplied by different companies, and for most consumer products, the equations estimating ALM are not disclosed. It is therefore difficult to use these equations for research purposes. In particular, the BIA equation is often age-dependent, which leads to fundamental difficulty in examining age-related ALM loss. The aims of the current study were: 1) to develop and validate an equation to estimate ALM using multi-frequency BIA (MF-BIA) using theoretical models, and 2) to establish sarcopenia cutoff values using the equation for the Japanese
Electric impedance tomography market is expected to gain market growth in the forecast period of 2020 to 2027. Data Bridge Market Research analyses the market to growing at a CAGR of 8.8% in the above-mentioned forecast period. Technological advancements and the rising prevalence of breast cancer are acting as the o...
TY - JOUR. T1 - Body composition in renal transplant patients: bioimpedance analysis compared to isotope dilution, dual energy X-ray absorptiometry, and anthropometry.. AU - van den Ham, E.C.H.. AU - Kooman, J.P.. AU - Christiaans, M.H.. AU - Nieman, F.H.M.. AU - van Kreel, B.K.. AU - Heidendal, G.A.K.. AU - van Hooff, J.P.. PY - 1999/1/1. Y1 - 1999/1/1. N2 - Department of Internal Medicine, University Hospital Maastricht, The Netherlands. [email protected] multifrequency bioelectrical impedance analysis (MF-BIA), a relatively new method for measuring body composition, is also applicable for accurate body composition measurements in renal transplant (RTx) patients is not known. Therefore, the use of MF-BIA is validated in 77 RTx patients with a stable renal function at least 2 yr posttransplantation. MF-BIA is compared to isotope dilution techniques for measurement of body water compartments, and to dual energy x-ray absorptiometry (DEXA) and anthropometry for measurement of ...
Bioelectrical impedance analysis (BIA) is a commonly used method for estimating body composition, and in particular body fat. Since the advent of the first commercially available devices in the mid-1980s the method has become popular owing to its ease of use, portability of the equipment. It is familiar in the consumer market as a simple instrument for estimating body fat. BIA actually determines the electrical impedance, or opposition to the flow of an electric current through body tissues which can then be used to estimate total body water (TBW), which can be used to estimate fat-free body mass and, by difference with body weight, body fat. Many of the early research studies showed that BIA was quite variable and it was not regarded by many as providing an accurate measure of body composition. In recent years technological improvements have made BIA a more reliable and therefore more acceptable way of measuring body composition. Nevertheless, it is not a gold standard or reference method. ...
In 20 mechanically ventilated patients who routinely undergo bronchoscopy Electrical Impedance Tomography (EIT) measurements whereby, evaluable data of 10 patients are needed, of about 1-2 minutes are performed directly before, directly after and 10, 30, and 60 minutes after bronchoscopy parallel to the following routine measurements: tidal volume, resistance, compliance, heart rate, blood pressure, SpO2 and blood gas values. Prior to the examination a rubber belt with 16 integrated electrocardiographic electrodes is placed around the thorax connected with an EIT- device. EIT data are generated by application of a small alternating current of 5mA and 50kHz and are stored and analyzed offline on a personal computer. The EIT provides a mapping of the distribution of the lung´s electrical impedance and exhibits a far temporal resolution of up to 40 tomograms per second. Because of electrical impedance of the pulmonal tissue is dependant to the air content, the air distribution within the lung over ...
Background: Roux-en-Y gastric bypass (RYGB) result in a marked reduction of body fat and also visceral fat (VF) decrease up to 36 % in 16 weeks. This leads to positive effects on cardiometabolic risks, which are known to be correlated with the occurrence of VF. This study analyzed the validity of bioelectrical impedance analysis (BIA) for determining VF in the postoperative course. In addition, magnetic resonance imaging (MRI) was performed for prediction of whole VF in bariatric patients on the basis of a single slice. Methods: Eighteen patients, who underwent RYGB (18), were included in this study. MRI and BIA measurements were performed 1 day before surgery, as well as 6, 12, and 24 weeks after surgery. Results: During the postoperative observation period, we found a significant decrease of both subcutaneous fat (SF) and VF. SF measured by MRI was highly correlated with the level of body fat shown by BIA. In contrast, the VF volume, as determined by MRI, showed no correlation with the body ...
Electrical bioimpedance measurement is widely used today for monitoring body condition. The applications include and go beyond, body composition assessment, nutritional status evaluation, and cancer detection. The modalities for interpreting the impedance information have also developed quickly over the recent decades from single frequency bioimpedance analysis to spectrum and to images.. Bioimpedance is measured by computing the relationship between voltage and current. In a current based bioimpedance measurement system, the stability of current source has a large influence on the performance of the system. This thesis compared three different voltage controlled current sources: enhanced Howland circuit, load-in-the-loop circuit driven by a current conveyor and double operational amplifiers circuit. These circuits were simulated in Multisim and manufactured into prototypes and tested in lab.. Effort has also been made to generate and collect signals with digital-to-analog convertor and ...
VAL104. Belarmino G,Gonzalez MC,Torrinhas RS,Sala P,Andraus W,Carneiro DAlbuquerque LA,Pereira RMR,Caparbo VF,Ravacci GR,Damiani L,Heymsfield SB,Waitzberg DL. World J Hepatol 2017 March 8; 9(7): 401-408. Background: To evaluate the prognostic value of the phase angle (PA) obtained from bioelectrical impedance analysis (BIA) for mortality prediction in patients with cirrhosis.. Subjects /Methods: In total, 134 male cirrhotic patients prospectively completed clinical evaluations and nutritional assessment by BIA to obtain PAs during a 36-mo follow-up period. Mortality risk was analyzed by applying the PA cutoff point recently proposed as a malnutrition marker (PA≤ 4.9°) in Kaplan-Meier curves and multivariate Cox regression models.. Results: The patients were divided into two groups according to the PA cutoff value (PA , 4.9°, n = 73; PA ≤ 4.9°, n = 61). Weight, height, and body mass index were similar in both groups, but patients with PAs , 4.9° were younger and had higher mid-arm muscle ...
TY - JOUR. T1 - Changes in biphasic electrode impedance with protein adsorption and cell growth. AU - Newbold, Carrie. AU - Richardson, Rachael. AU - Millard, Rodney. AU - Huang, Christie. AU - Milojevic, Dusan. AU - Shepherd, Robert. AU - Cowan, Robert. PY - 2010/10. Y1 - 2010/10. N2 - This study was undertaken to assess the contribution of protein adsorption and cell growth to increases in electrode impedance that occur immediately following implantation of cochlear implant electrodes and other neural stimulation devices. An in vitro model of the electrode-tissue interface was used. Radiolabelled albumin in phosphate buffered saline was added to planar gold electrodes and electrode impedance measured using a charge-balanced biphasic current pulse. The polarization impedance component increased with protein adsorption, while no change to access resistance was observed. The maximum level of protein adsorbed was measured at 0.5 μg cm-2, indicating a tightly packed monolayer of albumin molecules ...
The assessment of body composition has important applications in the evaluation of nutritional status and estimating potential health risks. Bioelectrical impedance analysis (BIA) is a valid method for the assessment of body composition. BIA is an alternative to more invasive and expensive methods l …
Application of bioelectrical impedance analysis and anthropometry as interchangeable methods to assess body composition of sportspersons.
0073]1A, 1B, 1C, 1D body fat measurement device [0074]10 control unit [0075]11 calculation processing section [0076]12 impedance measuring portion [0077]13 body fat mass calculating portion [0078]14 total fat mass calculating part [0079]15 site type fat mass calculating part [0080]16 visceral fat mass calculating part [0081]17 subcutaneous fat mass calculating part [0082]18 breathing state detecting portion [0083]21 constant current generation unit [0084]22 terminal switching unit [0085]23 potential difference detection unit [0086]24 physical information measurement unit [0087]25 subject information input unit [0088]26 display unit [0089]27 operation unit [0090]28 power supply unit [0091]29 memory [0092]30 body peripheral length measurement unit [0093]100A, 100A1, 100A2, 100B, 100C, 100D, 100D1 impedance measurement abdomen attachment unit [0094]101 device main body [0095]110A, 110A1, 110D, 110D1 abdomen rear surface side base portion [0096]112 support base [0097]112a one end [0098]112b other ...
Quantifying cell growth is essential for many applications in cell biology and biotechnology. It is required for optimizing cell culture conditions, for studying substances that inhibit or promote cell growth, for studying cancer progression, cytotoxicity assessment, biocompatibility characterization, etc. Traditional cell proliferation assays are label-based endpoint assays that require sample preparation and sophisticated lab equipment. An example of an alternative, label-free technique that is being currently employed for automating cell proliferation studies is electric cell-substrate impedance sending (ECIS). However, ECIS still requires external measurement instruments such as lock-in amplifiers and impedance analyzers. Researchers at the University of Maryland have developed a novel miniaturized technique in which CMOS capacitance sensors are employed to measure the capacitive coupling between on-chip sensing electrodes and the cellular matrix cultured on them, as a means of tracking cell ...
Linköping University, Department of Clinical and Experimental Medicine, Burn Center. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Sinnescentrum, Department of Plastic Surgery, Hand surgery UHL. Östergötlands Läns Landsting, Sinnescentrum, Department of Anaesthesiology and Surgery UHL. ...
The analysis of electrical signals originating from biological cells and tissues have yielded a large amount of useful information over the past years. Technologies have been developed, wherein we can monitor the health of the biological material of interest using these electrical signals. Instruments for the study of living cells have historically been of significant importance for such things as basic neuroscience, cell biology, pharmaceutical screening, environmental monitoring, and toxin detection. One of the practical realizations of these methods was successfully implemented by Giaver and Keese with their Electric Cell-Substrate Impedance Sensing (ECIS) system. The purpose of this Masters Thesis is to showcase the use of a Cellular Impedance Biosensor setup based on the ECIS system in real-time monitoring of endothelial barrier function and quantify the dynamic changes of the cytoskeleton filaments induced by different drugs. The filaments of the endothelial cell cytoskeleton play a ...
A simple and very accurate method for measuring the viscosity of liquids is presented. A vibrating lead zirconate titanate (PZT) ceramic polycrystalline resonator is totally immersed in a liquid and the oscillation behavior is studied both analytically and experimentally. The vibrating ceramic generates a shear wave traveling in the surrounding fluid normal to the surface of the resonator with heavy damping. The PZT is modeled as a vibrating thin plate. The resulting one-dimensional governing equation of motion, which includes the effect of damping, is solved with the appropriate damped boundary conditions using impedance methods. The resonance frequency of a PZT immersed in a fluid is shown to be a function of the PZT parameters and the product of the fluid density and viscosity. Fluid loading is shown to lower the resonance frequency of the ceramic and both diminish and broaden the impedance plot near resonance. Unlike previous methods utilizing crystal shear-mode resonators, this method is ...
More soldiers become ill or injured from disease and non-battle injuries than from combat, and providing good quality water supplies to the warfighter is a key element in preventing such injuries. Basic field water tests can detect only a few high priority threat chemicals, and comprehensive testing for additional chemicals can takes days or weeks. The ESB provides rapid toxicity identification for many industrial and agricultural chemicals in water. Rather than evaluating individual chemical constituents, the ESB system uses two individual biological-based sensors to identify toxic responses associated with the presence of chemicals: an electric cell-substrate impedance sensing (ECIS) device that measures changes electrical characteristics of a layer of vertebrate cells grown on fluidic biochips, and a pesticide sensor (also known as the ACE™ Rapid Test for Acetylcholinesterase Inhibitors, or ACE™ sensor) that measures enzyme inhibition caused primarily by carbamate and organophosphorus ...
Interelectrode impedance or electric field potential measurements are used to determine the relative orientation of one lead to other leads in the spinal column or other body/tissue location. Interelectrode impedance is determined by measuring impedance vectors. The value of the impedance vector is due primarily to the electrode-electrolyte interface, and the bulk impedance between the electrodes. The bulk impedance between the electrodes is, in turn, made up of (1) the impedance of the tissue adjacent to the electrodes, and (2) the impedance of the tissue between the electrodes. In one embodiment, the present invention makes both monopolar and bipolar impedance measurements, and then corrects the bipolar impedance measurements using the monopolar measurements to eliminate the effect of the impedance of the tissue adjacent the electrodes. The orientation and position of the leads may be inferred from the relative minima of the corrected bipolar impedance values. These corrected impedance values may also
Use of multifrequency bioelectrical impedance analysis for estimation of total body water and extracellular and intracellular fluid volumes in horses ...
SUNNYVALE, CA - November 17, 2008 - MDS Analytical Technologies, a leader in innovative solutions for drug-discovery and life-sciences research, today announced the delivery of the first three CellKeyTM384 Systems, the worlds first impedance-based, label-free, high-throughput instrument for use in drug-discovery research. Additional systems are scheduled to be delivered before the close of the calendar year.
TY - JOUR. T1 - Total body fat and the risk of Barretts oesophagus - A bioelectrical impedance study. AU - Kendall, Bradley J. AU - Macdonald, Graeme. AU - Prins, Johannes. AU - OBrien, Suzanne. AU - Whiteman, David. AU - Green, Adele. AU - Hayward, Nicholas. AU - Parsons, Peter. AU - Pavey, Sandra. AU - Purdie, David. AU - Webb, Penelope. AU - Gotley, David. AU - Smithers, B. AU - Jamieson, Glyn. AU - Drew, Paul. AU - Watson, David. AU - Clouston, Andrew. PY - 2014. Y1 - 2014. N2 - Background: Body mass index is associated with the risk of Barretts oesophagus (BO). It is uncertain whether this is related to total body fat or other factors that correlate with body mass index. We aimed to quantify the association between total body fat (measured by bioelectrical impedance) and risk of BO and examine if this association was modified by gastro-oesophageal reflux (GOR) and abdominal obesity. Methods: In 2007-2009, we surveyed 235 cases (69% Males, Mean age 62.1 years) and 244 age and sex matched ...
RFS5005A is a development platform for Electrical Impedance Tomography systems. It allows to use single RCL bridge or Impedance analyzer and switch its terminals between up to 16 electrodes. The design ensures low crosstalk and fast switching times. The RFS5005A contains: RFS5003B T-switch multiplexer board, linear- regulated power supply (+5V; -5V; +15V; -15V) and a universal metal rack 19
TY - JOUR. T1 - Identification of the human electrical impedance indifferent point. T2 - A surrogate for the volume indifferent point?. AU - Jarvis, Sara S.. AU - Pawelczyk, James A.. PY - 2009/8/12. Y1 - 2009/8/12. N2 - Head-up tilt (HUT) redistributes ∼700 mL of blood to the dependent regions. In a gravitational field, hydrostatic pressure is balanced against vascular compliance, resulting in a hydrostatic indifferent point (HIP) whose location should be coincident with an indifferent point for volume (VIP). Cardiac filling is determined by the hydrostatic gradient between the HIP/VIP and right atrium. We employed segmental impedance to examine blood volume redistribution during HUT and estimate the location of the VIP. During HUT, impedance increased in the chest and decreased in the lower abdomen, presumably due to blood volume shifts. Using a non-linear model to relate blood volume shifts to the hydrostatic gradient, we estimated the location of the electrical impedance indifferent point ...
Non-invasive single cell analyses are increasingly required for the medicaldiagnostics of test substances or the development of drugs and therapies on the single celllevel. For the non-invasive characterisation of cells, impedance spectroscopy whichprovides the frequency dependent electrical properties has been used. Recently,microfludic systems have been investigated to manipulate the single cells and tocharacterise the electrical properties of embedded cells. In this article, the impedance ofpartially embedded single cells dependent on the cellular behaviour was investigated byusing the microcapillary. An analytical equation was derived to relate the impedance ofembedded cells with respect to the morphological and physiological change ofextracellular interface. The capillary system with impedance measurement showed afeasibility to monitor the impedance change of embedded single cells caused bymorphological and physiological change of cell during the addition of DMSO. By fittingthe derived equation to
The ultra-wideband impedance sensor (UWBZ sensor, or Z-sensor) is implemented in differential and single-ended configurations. The differential UWBZ sensor employs a sub-nanosecond impulse to determine the balance of an impedance bridge. The bridge is configured as a differential sample-and-hold circuit that has a reference impedance side and an unknown impedance side. The unknown impedance side includes a short transmission line whose impedance is a function of the near proximity of objects. The single-ended UWBZ sensor eliminates the reference side of the bridge and is formed of a sample and hold circuit having a transmission line whose impedance is a function of the near proximity of objects. The sensing range of the transmission line is bounded by the two-way travel time of the impulse, thereby eliminating spurious Doppler modes from large distant objects that would occur in a microwave CW impedance bridge. Thus, the UWBZ sensor is a range-gated proximity sensor. The Z-sensor senses the near
Experimental setup. (a) Interface impedance measurement (schematic of impedance measurement (left), fabricated MEA on PCB (right)); (b) Charge injection limit m
A portable bioelectric impedance monitor for monitoring extracellular fluid levels includes a tetrapolar electrode array lead with four electrodes arranged sequentially and axially along the lead, and circuitry coupled with the at least four electrodes configured to measure bioelectric impedance extracellular fluid in a human subject at a frequency of less than 15 kHz. The electrodes are adhered to a human subject/patient on the patients torso or one of the patients limbs. One embodiment includes a Tetrapolar Analog Front End Patient Interface circuit configured to convert two electrode operation of a commercial Impedance Converter, Network Analyzer into a tetrapolar operation for excitation and impedance measurement of the human subject.
Electrical properties of food materials can give information about the inner structure and physiological state of biological tissues. Generally, the process of drying of fruits and vegetables is followed by weight loss. The aim of this study was to measure the impedance spectra of carrot slices during drying and to correlate impedance parameters to moisture content in different drying periods. Cylindrical slices were cut out from the carrot root along the axis. The slices were dried in a Venticell 111 air oven at 50°C. The weight of the slices was measured with a DenverSI-603 electronic analytical and precision balance. The weighing of the samples was performed every 30 min at the beginning of drying and every 60 min after the process. The moisture content of the samples was calculated on wet basis. The magnitude and phase angle of electrical impedance of the slices were mea-sured with HP 4284A and 4285A precision LCR meters in thefrequency range from 30 Hz to 1 MHz and from 75 kHz to 30 ...
BIOPAC Biopotential Amplifiers are specialized differential amplifiers designed to amplify the uV and mV level biopotentials that are generated by living organisms. Biopotentials are electrical signals (voltages) that are generated by physiological processes occurring within the body. Biopotentials are produced by the electrochemical activity of a type of cell, called an excitable cell. Excitable cells are found in the nervous, muscular and glandular systems in the body. When an excitable cell is stimulated, it generates an action potential, which is the essential source of biopotentials in the body. The body sources other biopotentials that are not directly related to action potentials. Examples include the corneal-retinal (corneoretinal) potential, skin potential and the electromechanical behavior of bone. In addition, many physiological processes in the body contribute to measurable impedance changes. Impedance changes are sensed by applying external excitation signals that convert impedance ...
In children 8-12 years old, BMI gives a good estimation of the total body fat as measured on MRI. The estimation will be improved when both BEI and BMI are used in the prediction. Bioelectrical impedance has a low correlation with total body fat and its use alone in estimating total body fat is not …
High-frequency digital sign processors suffer from electro-magnetic disturbance, because of its ever-increasing integration procedure and level acceleration. can be proportional to range can be inversely proportional to range and C inversely. Therefore, simplified equivalence, as well as the impedance can be depicted in Fig.?3. Fig.?3 Comparative circuit magic size As is demonstrated in Fig.?4, to be able to determine guidelines from the circuit, means the exterior impedance from the source, for the same internal current way to obtain the LSI/IC under measurement, as well as for the same internal impedance of these devices under measured. These devices internal impedance could be assessed by an impedance analyser, as can be proven in Fig.?5. The resonance frequency could be observed through the impedance diagram then. The resulting guidelines (and with an impedance analyser The exterior circuit current could KW-2449 be assessed by a range analyser as well as the particular sketch can be ...
Measuring and Managing Healthy Living The US spends more on healthcare per capita ($8668) and more on healthcare as a percentage of GDP (17.2%) than any other nation. From 2011 data
Buy ASTM A 1038 : 2005 Standard Practice for Portable Hardness Testing by the Ultrasonic Contact Impedance Method from SAI Global
Read chapter 7 Bioelectrical Impedance: A History, Research Issues, and Recent Consensus: The latest of a series of publications based on workshops sponso...
Personal and family medical history, smoking status, exercise, medication use, anthropometric data, and laboratory test results were collected during health check-ups. Subjects were categorized with regard to smoking status (never, past smoker, or current smoker). Exercise status was assessed via self-report questionnaires but frequency or time of exercise was not available (none or regular exercise).. Body weight and height were measured and BMI was calculated as kg/m2. Obesity was defined according to the criteria for the Asian and Pacific regions (BMI ≥ 25 kg/m2) [19]. Waist circumference was examined at the point between the upper iliac crest and the lowest rib after normal expiration. Blood pressure was measured by trained nurses using a mercury sphygmomanometer after at least 5 min of rest in a sitting position. Skeletal muscle mass for each limb (kg), fat mass (kg), and percent fat mass (%) were estimated via bioelectrical impedance analysis (BIA) measurements using a multifrequency BIA ...
Elastic nature of the viscoelastic fluids induces lateral migration of particles into a single streamline and can be used by microfluidic based flow cytometry devices. In this study, we investigated focusing efficiency of polyethylene oxide based viscoelastic solutions at varying ionic concentration to demonstrate their use in impedimetric particle characterization systems. Rheological properties of the viscoelastic fluid and particle focusing performance are not affected by ionic concentration. We investigated the viscoelastic focusing dynamics using polystyrene (PS) beads and human red blood cells (RBCs) suspended in the viscoelastic fluid. Elasto‐inertial focusing of PS beads was achieved with the combination of inertial and viscoelastic effects. RBCs were aligned along the channel centerline in parachute shape which yielded consistent impedimetric signals. We compared our impedance‐based microfluidic flow cytometry results for RBCs and PS beads by analyzing particle transit time and peak ...
Abstract The acoustical scattering cross section is usually employed to evaluate the scattering ability of the bubbles when they are excited by the incident acoustic waves. This parameter is strongly related to many important applications of performance prediction for search sonar or underwater telemetry, acoustical oceanography, acoustic cavitation, volcanology, and medical and industrial ultrasound. In the present paper, both the analytical and numerical analysis results of the acoustical scattering cross section of a single bubble under multi-frequency excitation are obtained. The nonlinear characteristics (e.g., harmonics, subharmonics, and ultraharmonics) of the scattering cross section curve under multi-frequency excitation are investigated compared with single-frequency excitation. The influence of several paramount parameters (e.g., bubble equilibrium radius, acoustic pressure amplitude, and acoustic frequencies) in the multi-frequency system on the predictions of scattering cross ...
Michelle is Trained in and an accredited user of the Bioelectrical Impedance Analyser (BIA) for Body Composition analysis and cellular health Analysis. She is also Trained in the Bradford Blood Techniques (Live and Dry). These tools are used in your personalised Consultation. Michelle Continuously furthers her education to better help her patients each year by attending local and interstate trainings as well as scheduled monthly mentoring sessions with other practitioners. ...
article{2988888, author = {Kurz, Christian and Büth, Heiko and Sossalla, Adam and Vermeersch, Vincent and Toncheva, Veska and Dubruel, Peter and Schacht, Etienne and Thielecke, Hagen}, issn = {0956-5663}, journal = {BIOSENSORS & BIOELECTRONICS}, keywords = {Single cell impedance,Electrical biosensor,Membrane integrity,Polymer/polymer-DNA complex,Finite element method,DIELECTRIC-PROPERTIES,SPECTROSCOPY,SYSTEM}, language = {eng}, number = {8}, pages = {3405--3412}, title = {Chip-based impedance measurement on single cells for monitoring sub-toxic effects on cell membranes}, url = {http://dx.doi.org/10.1016/j.bios.2011.01.012}, volume = {26}, year = {2011 ...
Method and apparatus for monitoring a plurality of physiological factors contributing to physiological conditions of a heart, that determines a first impedance, corresponding to the plurality of physiological factors, across a plurality of vectors, and a second impedance, corresponding to the plurality of physiological factors, across the plurality of vectors subsequent to determining the first impedance. A relative change in impedance corresponding to the plurality of vectors is determined in response to the first impedance and the second impedance, first minimally contributing physiological factors of the plurality of physiological factors associated with a first physiological factor of the plurality of physiological factors are determined, and relative change in tissue resistivity corresponding to the first physiological factor in response to physiological factors of the plurality of physiological factors other than the first minimal contributing physiological factors and the relative change in
The invention provides a convenient and non-invasive means to prepare cells, tissues, and organs for electrical transmission and reception. In an embodiment of the invention, a control method comprises the use of at least one skin electrode, as a reference electrode, and an electrical sensor to measure periodically or continuously the skins electrical conductance at the site of preparation. The dynamic change in the conductance through the skin is measured while the ultrasound is applied. Signal processing is performed on the measurement and the level of skin impedance change is controlled by performing a mathematical analysis and using the results of such analysis to control the application of ultrasonic energy. A desired level of skin impedance can be set at a predetermined value or based on a chosen level of skin integrity, subjects sensation of discomfort, or duration of the ultrasound application.
Context: The use of predictive equations in hospital settings lacking access to dual energy X-ray absorptiometry or bioelectrical impedance analysis (BIA) can be beneficial because cachexia, muscle wasting and related increase in morbidity and mortality are known occurrences in patients with chronic obstructive pulmonary disease (COPD). Aim: To analyse the predictive performance of reported equations for fat-free mass (FFM) prediction against BIA-derived FFM in patients with stable COPD. Design/Materials and Methods: Seventy-two male patients aged between 40 and 75 years with stable COPD were evaluated for FFM by BIA. FFM was also predicted for the same patients using equations reported by Kulkarni et al., Solomon Yu et al., Janmahasatian et al., as well as Deurenberg equation. Statistical Analysis Used: The predictive performance was assessed by Bland-Altman plots, with subsequent calculations of bias, precision and accuracy. The performance was also analysed across the age and body mass index ...
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 - 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
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 ...
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 ...
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 ...
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 ...
Electrical impedance spectroscopy is a non-destructive method for analysing the structure and properties on different materials and objects.
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.
Physiology Journal is a peer-reviewed, Open Access journal that publishes original research articles, review articles, and clinical studies in all areas of physiology.
Biomedical engineering meets acupuncture - development of a miniaturized 48-channel skin impedance measurement system for needle and laser acupuncture. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
TY - GEN. T1 - A low power configurable bio-impedance spectroscopy (BIS) ASIC with simultaneous ECG and respiration recording functionality. AU - Xu, J.. AU - Harpe, P.J.A.. AU - Pettine, J.. AU - Van Hoof, C.. AU - Yazicioglu, R.F.. PY - 2015/10/30. Y1 - 2015/10/30. N2 - This paper presents a power-efficient ASIC for bio-impedance spectroscopy, as well as ECG and respiration recording. The ASIC includes a wideband stimulation current source with a pseudo-random binary sequence, a low-noise instrumentation amplifier, and a low power 12b SAR ADC. This ASIC is able to measure bio-impedances from 1ω to 10kω with 0.1ω resolution, and covers a frequency range up to 125kHz. Furthermore, the ASIC can simultaneously record ECG and respiration while consuming only 31μW from a 1.8V supply.. AB - This paper presents a power-efficient ASIC for bio-impedance spectroscopy, as well as ECG and respiration recording. The ASIC includes a wideband stimulation current source with a pseudo-random binary ...
A transdermal transport device includes a reservoir for holding a formulation of an active principle, a needle with a bore through which the formulation is transported between the reservoir and a target area of a biological body, and an impedance sensor. The impedance sensor has an electrode positioned to measure the impedance of a portion of the target area between the needle and the electrode to indicate the depth of penetration of the needle into the target area.
The opportunistic pathogen, Pseudomonas aeruginosa, is infamous for its ability to rapidly form biofilms (<24 h) in inhospitable environments and the development of antimicrobial resistance (AMR). It has been seen to have resistance to nearly all known antibiotics, including last-line antibiotics colistin and carbapenems. AMR is currently considered one of the biggest threats to human health, causing 700,000 deaths annually, expected to rise to 10 million deaths per year by 2050. P. aeruginosa, alongside other opportunistic pathogens, has been implicated in infections following various surgical procedures. Such infections compromise patient recovery and, when a medical implant is present a biofilm can develop that will ultimately require a complex revision surgery to remove the infection. In this study, impedance spectroscopy and differential pulse voltammetry were carried out in parallel to measure electrochemical and impedance properties of bacteria, allowing for identification and quantification
Low-impedance electric discharge device. U.S. Patent No. 1,629,009. System for converting sound waves into electrical waves. U. ... 17 May 1927). Low-impedance electric discharge device. U.S. Patent No. 1,629,009.Washington, DC: U.S. Patent and Trademark ... Electrical cut-out. U.S. Patent No. 1,480,225. Oscillation generator. U.S. Patent No. 1,579,895. Electric ignition system. U.S ... His present occupation was electrical engineer and employed by the Western Electric Co. located at 463 West Street in New York ...
DI or DI Box An electronic device which alters the impedance of electric instrument signals (e.g. electric guitar, electric ... With electric guitars, electric basses, Hammond organs, electric piano, and other electric instruments, performers often ... The DI box converts a high-impedance, unbalanced signal from an electric guitar into a low-impedance, balanced signal. Many DI ... ohm A unit of electrical impedance; speakers, microphones, headphones, and other gear is rated with its nominal impedance. (See ...
The impedance can be measured from difference in amplitude. The impedance has two components: electrical conductivity and ... This method measures the electrical impedance. Electromagnetic waves traveling along Transmission Line (TL) enter in soil ... medium whose impedance is different from TL a part of the energy is reflected back to transmitter. The reflected wave ...
Electrical impedance tomography, Adam Hilger, Bristol, England, 1990. Webster, J. G. (ed.), Teaching design in electrical ... He first proposed the idea of electrical impedance tomography as a medical imaging technique in a publication in 1978. In his ... of Electrical Eng., Univ. of Wisconsin-Madison 1976-80 Director of Biomedical Eng. Ctr., Univ. of Wisconsin-Madison 1973-1999 ... John O.G. Webster is an American electrical engineer and a founding pioneer in the field of biomedical engineering. In 2008, ...
In a more recent collaboration, the electrical impedance spectroscopy platform (EISP) was launched together with French ... "Market Leaders Join Forces in Electrical Impedance Spectroscopy". UHFLI 600 MHz Lock-in Amplifier from Zurich Instruments HF2LI ... Fluigent and Dutch Micronit for the commercialization of ready-to-use electrical impedance analysis system. Lock-in Amplifier ... 5 MHz Lock-in Amplifier from Zurich Instruments MFIA 5 MHz Impedance Analyzer from Zurich Instruments UHFAWG Arbitrary Waveform ...
Cole KS (1939). "Electrical impedance of the squid giant axon during activity". J. Gen. Physiol. 22 (5): 649-670. doi:10.1085/ ... The interaction of electrical and osmotic relations in plant cells indicates an osmotic function of electrical excitability in ... Electric Biology, the study of the electrical processes in the organism represented on a modern basis]. Braunschweig: Vieweg ... The electrical properties of a cell are determined by the structure of the membrane that surrounds it. A cell membrane consists ...
This is the mathematical formulation of electrical impedance tomography. The solution of partial differential equation in an ... tangential electric field on the boundary of a region to the equivalent electric current on its boundary. Fluid-structure ...
Evaluation of Electrical Impedance as a Biomarker of Myostatin Inhibition in Wild Type and Muscular Dystrophy Mice. PLoS One. ... Electrical impedance myography in the assessment of disuse atrophy. Arch Phys Med Rehabil. 2009 Oct;90(10):1806-10". Missing or ... These devices rely on the use of electrical impedance myography (EIM) to measure muscle quality. EIM has been used to evaluate ... Age- and gender-associated differences in electrical impedance values of skeletal muscle. Physiol Meas. 2013 Dec;34(12):1611-22 ...
This notation is frequently used to represent an electrical impedance. In this case, the phase angle is the phase difference ... In bioelectrical impedance analysis in humans, an estimate of the phase angle can be obtained and is based on changes in ... 2005). "Bioelectrical impedance analysis: population reference values for phase angle by age and sex". American Journal of ... between the voltage applied to the impedance and the current driven through it. In the context of periodic phenomena, such as a ...
Electrical termination Electrical impedance Grid resistor Kleinschmidt, Kirk, ed. (1990). ARRL Handbook for the Radio Amateur. ... Load banks are connected to electrical power supplies to simulate the supply's intended electrical load for testing purposes. ... A dummy load is a device used to simulate an electrical load, usually for testing purposes. In radio a dummy antenna is ... The dummy load ordinarily should be a pure resistance; the amount of resistance should be the same as the impedance of the ...
The other is bioelectrical impedance analysis which uses electrical resistance. Bioelectrical impedance has not been shown to ...
Ringing can be due to signal reflection, in which case it may be minimized by impedance matching. In video circuits, electrical ... Microphonics Ripple (electrical) Impedance matching Oxford English Dictionary (2nd ed.). Oxford University Press. 1989. f. The ... In electrical circuits, ringing is an unwanted oscillation of a voltage or current. It happens when an electrical pulse causes ...
Electrical impedance of acupuncture meridians: the relevance of subcutaneous collagenous bands. PLoS One. 2010; 5(7):e11907. 16 ... Electrical impedance along connective tissue planes associated with acupuncture meridians. BMC Complement Altern Med. 2005; 5: ... Electrical properties of acupuncture points and meridians: a systematic review. Bioelectromagnetics. 2008 May; 29(4):245-56. 24 ...
The negative impedance converter is an example of such a circuit. Reactance is the imaginary part of the complex electrical ... A series LC circuit has an impedance that is the sum of the impedances of an inductor and capacitor, Z = i ω L + 1 i ω C = i ( ... This is sometimes referred to as the driving point impedance because it is the impedance at the place in the network at which ... This result may seem counterintuitive since admittance is the reciprocal of impedance, but is easily proved. If the impedance ...
A simple solution is to add electrical impedance to the circuit. This limits the rate at which current can increase, which ... Electric power distribution systems include circuit breakers to disconnect power in case of a fault, but to maximize ... A fault current limiter is a nonlinear element which has a low impedance at normal current levels, but presents a higher ... In normal operation, current flows through the superconductor without resistance and negligible impedance. If a fault develops ...
From 1959 until 1973 Ranck analyzed the flow of electric current in brain, electrical properties of glia, electric impedance of ... Electrical impedance in the subicular area of rats during paradoxical sleep. Ranck JB Jr. Exp Neurol. 1966 Dec;16(4):416-37. ... In the early phase Ranck studied impedance in the brain, providing basic data for any studies or procedures that employ ... Which elements are excited in electrical stimulation of mammalian central nervous system: a review. Ranck JB Jr. Brain Res. ...
... electrical impedance is also measured in ohms. The siemens (symbol: S) is the SI derived unit of electric conductance and ... It is desirable that one unit of electrical potential will force one unit of electric current through one unit of electrical ... Electrical units so defined were not a coherent system with the units for energy, mass, length, and time, requiring conversion ... Alternatively, the electrical units can be related to the mechanical units by defining, for example, a unit of current that ...
However, modern SDRAM chips exemplify the problem of electrical impedance discontinuity.[clarification needed] Fully Buffered ... A multidrop bus (MDB) is a computer bus in which all components are connected to the electrical circuit. A process of ...
Termination resistors also reduce electrical noise sensitivity due to the lower impedance. The value of each termination ... Electrical signaling is balanced, and multipoint systems are supported. The standard is jointly published by the ... Grounds between buildings may vary by a small voltage, but with a very low impedance and hence the possibility of catastrophic ... RS-485, also known as TIA-485(-A), EIA-485, is a standard defining the electrical characteristics of drivers and receivers for ...
Kim, K. Y., Kim, B. S., Kim, M. C., Lee, K. J., Ko, Y. J. and Kim, S. (2005). "Electrical impedance imaging of two-phase flows ... Electrical impedance tomography (EIT) is a non-invasive imaging modality in which a cross sectional image of the conductivity ... Boundary estimation in EIT is the term used in the field of electrical impedance tomography, if the inverse problem is the ... Vauhkonen, M. (1997). "Electrical impedance tomography and prior information", PhD Thesis University of Kuopio, Finland online ...
"Beef meat electrical impedance spectroscopy and anisotropy sensing for non-invasive early assessment of meat ageing". Journal ... An electrical impedance study". New Zealand Journal of Crop and Horticultural Science. 25 (2): 149-157. doi:10.1080/ ... Mabrook, M.F.; Petty, M.C. (2003). "Effect of composition on the electrical conductance of milk". Journal of Food Engineering. ... Rehman, M.; Abu Izneid, J.A.; Abdullha, M.Z.; Arshad, M.R. (2011). "Assessment of quality of fruits using impedance ...
Electrical impedance sensor, which consists of soil probes and using electrical impedance measurement. The most common ... The oscillator signal is propagated along the transmission line into the soil probe, and if the probe's impedance differs from ... However, because of the complex electrical field around the probe, the sensor needs to be calibrated for different soil types. ... Measurement of soil water content using a simplified impedance measuring technique. Journal of Agricultural Engineering ...
Parametric electrical impedance tomography (pEIT): a novel method that accurately identifies early hemodynamic changes, prior ... Electrical thoracic scan system. 2013. CardioLogic Innovations Ltd., assignee. Electrical thoracic scan system. Method of ... Parametric electrical impedance tomography: a novel noninvasive method that accurately identifies pulmonary congestion. ... The company secured several patents that utilized technology for patient monitoring, a system for electrical thoracic scans, ...
Impedance cardiography (often abbreviated as ICG, or Thoracic Electrical Bioimpedance (TEB)) measures changes in electrical ... Electrical Cardiometry is a non-invasive method similar to Impedance cardiography; both methods measure thoracic electrical ... Electrical Cardiometry is a method trademarked by Cardiotronic, Inc., and shows promising results in a wide range of patients. ... Lower impedance indicates greater intrathoracic fluid volume and blood flow. By synchronizing fluid volume changes with the ...
It is only necessary that the electrical impedances are symmetrical. It is possible to design circuits that are not physically ... The impedance to ground of both legs is the same and the line remains balanced. The receiving amplifier still rejects any ... In a balanced line the two signal lines are of a matched impedance to help ensure that interference induced in the line is ... If one wire has a higher impedance to ground it will tend to have a higher noise induced, destroying the balance. A balanced ...
The particle's orientation with the optical electric field may also help determine the impedance. Conventional silicon ... The polyimide cap protects the screen and helps reduce any impedance mismatch that might occur when the wave crosses from the ... In a conventional material, the response to electric and magnetic fields, and hence to light, is determined by atoms. In ... Therefore, the main current flow is actually the electric displacement current density ∂D / ∂t, and can be termed as the " ...
published in paperback February 1994, ISBN 0-7506-1940-6). Electrical Impedance Tomography, M. Wang, F. Dickin and R.A. ... Electrical resistance tomography of metal walled vessels and pipelines, M. Wang, F.J. Dickin and R.A. Williams, Electronics ... For example, electrical sensors have been used to replace nuclear density gauges routinely in hydraulic dredging with major ... Industrial monitoring of hydrocyclone operation using electrical resistance tomography, R.A. Williams, X. Jia, R.M. West, M. ...
He is especially well known for his pioneering work with David C. Barber on electrical impedance tomography (EIT). He is also ... Holder D.S., Electrical Impedance Tomography: Methods, History and Applications, Institute of Physics, 2004. ISBN 0-7503-0952-0 ... Schwan Award for Pioneering Research into Electrical Impedance Tomography Barber, D.C.; Brown, B.H. (1984). "Applied Potential ... noted for his work on the recording and understanding of the electrical activity of the gut, the analysis of nerve action ...
For the relationship between the electric and magnetic fields, see the impedance of free space. For a 50 Ω load, knowing that ... For an electric field antenna, the field strength is in units of V/m or µV/m and the resulting antenna factor AF is in units of ... In electromagnetics, the antenna factor is defined as the ratio of the electric field strength to the voltage V (units: V or µV ...
The method of Professor Kobayashi performs a calculation of the ratio of the measured impedance of two or more electric ... Sonada measures the canal's impedance using one or more electric frequencies. The method tracks the penetration of the ... manually or with a mechanical canal instrument that passes a low intensity electric current through the tooth. The electrical ...
... layer to form an anti-reflection coating can be thought of as analogous to the technique of impedance matching of electrical ...
Wave impedance[edit]. See also: Wave impedance. The wave impedance of a plane electromagnetic wave in a non-conductive medium ... The strong electric field of high intensity light (such as output of a laser) may cause a medium's refractive index to vary as ... Thus refractive index in a non-magnetic media is the ratio of the vacuum wave impedance to the wave impedance of the medium. ... is the vacuum wave impedance, μ and ϵ are the absolute permeability and permittivity of the medium, εr is the material's ...
dB electrical.. dBo. dB optical. A change of 1 dBo in optical power can result in a change of up to 2 dBe in electrical signal ... dB(VRMS) - voltage relative to 1 volt, regardless of impedance.. dBVU. dB volume unit. dBW. dB(W) - power relative to 1 watt.. ... "Electrical Engineering. 73 (6): 550-555. doi:10.1109/EE.1954.6438830.. *^ "Meeting minutes" (PDF). Consultative Committee for ... dB electrical.. dBf. dB(fW) - power relative to 1 femtowatt.. dBFS. dB(full scale) - the amplitude of a signal compared with ...
Derived electrical parameters[edit]. *Characteristic impedance in ohms (Ω). The complex impedance Z of an infinite length of ... The characteristic impedance is given by[9] Z. 0. =. 1. 2. π. μ. ϵ. ln. ⁡. D. d. ≈. 60. Ω. ϵ. r. ln. ⁡. D. d. ≈. 138. Ω. ϵ. r. ... That value is Z0, the characteristic impedance of the cable: Z. 0. =. s. L. s. C. =. L. C. {\displaystyle Z_{0}={\sqrt {\frac { ... Choice of impedance[edit]. The best coaxial cable impedances in high-power, high-voltage, and low-attenuation applications were ...
The most practical dissociation method is probably an electrical discharge.[ambiguous] Argon-hydrogen gas compositions with ... leading to random malfunctions on circuits with high impedances. Different types of fluxes are differently prone to cause these ... Electrical solder with a rosin core, visible as a dark spot in the cut end of the solder wire. ... Deterioration of electrical properties of printed circuit boards, as soldering temperatures are above the glass transition ...
Institute of Electrical and Electronic Engineers. 40 (10): 640. doi:10.1109/81.246140. Retrieved February 6, 2014.. ... One version of Chua's circuit, where the nonlinear Chua's diode is synthesized by an op amp negative impedance converter (OPA1 ... Institute of Electrical and Electronic Engineers. 40 (10): 658. doi:10.1109/81.246141. Retrieved February 6, 2014.. ... The function f(x) describes the electrical response of the nonlinear resistor, and its shape depends on the particular ...
Impedance: A test to measure lead integrity. Large and/or sudden increases in impedance can be indicative of a lead fracture ... "IEEE Milestone in Electrical Engineering and Computing". Retrieved September 5, 2009.. *^ Harvard News Office. "Harvard Gazette ... In 1950, Canadian electrical engineer John Hopps designed and built the first external pacemaker based upon observations by ... Note the circle around one of the sharp electrical spike in the position where one would expect the P wave. ...
The load that a driver presents to an amplifier consists of a complex electrical impedance-a combination of resistance and both ... When an electrical signal is applied to the voice coil, a magnetic field is created by the electric current in the voice coil, ... In the examples that follow, assume (for simplicity) that the drivers being compared have the same electrical impedance, are ... Electrical characteristics of dynamic loudspeakers[edit]. Main article: Electrical characteristics of dynamic loudspeakers ...
The fourth unit could be chosen to be electric current, voltage, or electrical resistance.[50] Electric current with named unit ... resistance, impedance, reactance V/A kg⋅m2⋅s−3⋅A−2. ... electric charge or quantity of electricity s⋅A volt V voltage ( ... Giorgi later identified the need for an electrical base unit, for which the unit of electric current was chosen for SI. Another ... electrical conductance is the inverse of electrical resistance, with the consequence that the siemens is the inverse of the ohm ...
Also of help in the action of peristalsis is the basal electrical rhythm that determines the frequency of contractions.[35] The ...
A high-voltage, direct current (HVDC) electric power transmission system (also called a power superhighway or an electrical ... A detailed knowledge of the harmonic impedance of the AC system, at a wide range of frequencies, is needed in order to design ... Electric power distribution. Electricity economics. Power station technology. Portals. Energy. Renewable energy. Sustainable ... Corona discharge is the creation of ions in a fluid (such as air) by the presence of a strong electric field. Electrons are ...
Since a small loop antenna is essentially a coil, its electrical impedance is inductive, with an inductive reactance much ... Since the transverse magnetic and electric fields of a propagating electromagnetic wave are at right angles, the electric field ... In addition to other common impedance matching techniques such as a gamma match, transmitting loops are sometimes impedance ... impedance. A parallel resonance, on the other hand, leads to a very large impedance seen at the feedpoint when the capacitor's ...
Electrical impedance. *Extra-sensory perception. *Human Potential Movement. *Hypnosis. *Large Group Awareness Training ...
Micro hybrid electric vehicles batteries were tested at a 70% SoC in a pulse charge-discharge pattern. UltraBattery had about ... The 'smart building' system, which includes 163 UltraBattery cells (500 Ah, 2 volts), also monitors cell voltage, impedance and ... PNM, the leading electric utility company in New Mexico, United States, has integrated an UltraBattery energy storage system ... UltraBattery can be used for a range of energy storage applications, such as: In hybrid electric vehicles (HEVs) To store ...
The charge remains until it is able to move away by means of an electric current or electrical discharge. Static electricity is ... Transformer oil is part of the electrical insulation system of large power transformers and other electrical apparatus. Re- ... and at least one of the surfaces has a high resistance to electric current (and is therefore an electrical insulator). The ... J. J. Lowke (1992). "Theory of electrical breakdown in air". Journal of Physics D: Applied Physics. 25 (2): 202-210. Bibcode: ...
"University of Maryland; Electrical Engineering Department. Retrieved 2009-07-07.. *^ Ward, David W.; Nelson, Keith A; Webb, ... Since the flow of energy remains the same in both materials (media), the impedance of the NIM matches the RHM. Hence, the sign ... In ordinary optical materials, the curl equation for the electric field show a "right hand rule" for the directions of the ... This first composite metamaterial is then composed of split-ring resonators and electrical conducting posts.[5] ...
Grossi, M.; Lazzarini, R.; Lanzoni, M.; Riccò, B. (2011). "A novel technique to control ice-cream freezing by electrical ... Grossi, M.; Lanzoni, M.; Lazzarini, R.; Riccò, B. (2012). "Automatici ce-cream characterization by impedance measurements for ...
Electrical engineeringWikipedia:WikiProject Electrical engineeringTemplate:WikiProject Electrical engineeringelectrical ... The impedance has a rectangular box, but it is filled with black, not empty like a resistor. -Preceding unsigned comment added ... Why is power(electric) transmitted at high voltage when power loss due to ohmic heating is V2/R as well as I2R? Why does the ... Pretty much every electrical circuit uses resistors for one purpose or another. The simplest application I can think of would ...
Propagation of electric pulses in cables is used to detect and localize defects in electric wiring. Ultrasonic reflectometry: A ... The waves reflected at the interface travel back to the transducer, then the impedance of a sample is determined by measuring ...
the intrinsic wave impedance of a medium (e.g. the impedance of free space) ... the SI unit measure of electrical resistance, the ohm. *angular velocity / radian frequency (rev/min) ...
Distortion is most commonly used with the electric guitar, but may also be used with other electric instruments such as bass ... With no change in flux there is no back E.M.F. and hence no reflected impedance. The transformer and valve combination then ... These effects are used with electric guitars, electric basses (fuzz bass), electronic keyboards, and more rarely as a special ... A. J., Millard (2004). The Electric Guitar: A History of an American Icon. JHU Press. p. 136.. ...
Electrical properties include conductivity, resistance, impedance and capacitance. Electrical conductors such as metals and ... Thus, electrical power grids rely on metal cables to distribute electricity. Home electrical systems, for example, are wired ... A capacitor is an electrical device that can store energy in the electric field between a pair of closely spaced conductors ( ... A dielectric, or electrical insulator, is a substance that is highly resistant to the flow of electric current. A dielectric, ...
is the electrical conductivity, ω. {\displaystyle \omega }. is the field frequency, and i. {\displaystyle i}. is the imaginary ... impedance sensing: particles collecting at the electrode edge have an influence on the impedance of the electrodes - this ... Dielectrophoresis occurs when a polarizable particle is suspended in a non-uniform electric field. The electric field polarizes ... Pohl, H. A. (1978). Dielectrophoresis: The Behavior of Neutral in Nonuniform Electric Fields. Cambridge University Press. ISBN ...
A generic vector wave for the electric field. E. =. E. 0. f. (. k. ^. ⋅. x. −. c. 0. t. ). {\displaystyle \mathbf {E} =\mathbf ... Impedance of free space. *Radiation reaction. *Risks and benefits of sun exposure ... In electrical conductors, such induced bulk movement of charges (electric currents) results in absorption of the EMR, or else ... In fact, magnetic fields can be viewed as electric fields in another frame of reference, and electric fields can be viewed as ...
The impedance seen by the panel determines the operating point of the solar panel. Thus by varying the impedance seen by the ... For most purposes, FF, Voc, and Isc are enough information to give a useful approximate model of the electrical behavior of a ... Changing the duty ratio of the DC-DC converter results in an impedance change as seen by the panel. At a particular impedance ( ... Electrical circuits can be designed to present arbitrary loads to the photovoltaic cells and then convert the voltage, current ...
"Recent Patents on Electrical & Electronic Engineering (Formerly Recent Patents on Electrical Engineering). 2 (1): 27-39. doi: ... For low impedance loads near zero ohms, as the generator resistance rises the power delivered to the load decreases. To lower ... Unlike heat engines, the solid state electrical components typically used to perform thermal to electric energy conversion have ... A direct electric current will flow in the circuit when there is a temperature difference between the ends of the materials. ...
the secondary circuit load impedance can be expressed as eq. 6. *the apparent load impedance referred to the primary circuit is ... A transformer is a static electrical device that transfers electrical energy between two or more circuits through ... is the load impedance of the secondary circuit & Z. L. ′. {\displaystyle Z'_{\text{L}}}. is the apparent load or driving point ... Harlow, James (2004). Electric Power Transformer Engineering (PDF). CRC Press. ISBN 0-8493-1704-5.. [permanent dead link] ...
Western Electrical Company. 1969. p. 2.1.. .mw-parser-output cite.citation{font-style:inherit}.mw-parser-output .citation q{ ... Sound impedance. *Sound intensity level. *Sound power. *Sound power level. General. *Acoustic theory ...
Electric vehicles[edit]. Main articles: Electric vehicle, Battery electric vehicle, Electric car, and Patent encumbrance of ... Retention of charge depends in large part on the battery's impedance or internal resistance (the lower the better), and on its ... Applications of NiMH electric-vehicle batteries include all-electric plug-in vehicles such as the General Motors EV1, first- ... Shnayerson, Michael (1996-08-27). The Car That Could: The Inside Story of GM's Revolutionary Electric Vehicle. Random House. pp ...
Strong, short electrical pulses from the ultrasound machine drive the transducer at the desired frequency. The frequencies can ... Specifically, sound is reflected anywhere where there are acoustic impedance changes in the body: e.g. blood cells in blood ... The greater the difference between acoustic impedances, the larger the echo is. If the pulse hits gases or solids, the density ... The speed of sound varies as it travels through different materials, and is dependent on the acoustical impedance of the ...
Bio-electrical Impedance Analysis (BIA) is a simple painless procedure which enables a doctor or healthcare provider to analyze ... Bio-electrical Impedance Analysis (BIA) is a simple painless procedure which enables a doctor or healthcare provider to analyze ... Then a small electrical current is passed through the body and measurements are made. The electrical current is so small that ...
... s electrical impedance and exhibits a far temporal resolution of up to 40 tomograms per second. Because of electrical impedance ... Electric Impedance Tomography Bronchoscopy Change in Lung Impedance Due to Ventilation Recruitment Improvement the Treatment of ... Bronchoscopy and Electric Impedance Tomography (EIT) Pilot Study (Broncho-EIT). The safety and scientific validity of this ... Electrical Impedance Tomography (EIT)is a technique based on the injection of small currents and voltage measurements using ...
Liquid viscosity measurement using a longitudinally vibrating PZT ceramic and electric impedance measurements Author(s): Osama ... Fluid loading is shown to lower the resonance frequency of the ceramic and both diminish and broaden the impedance plot near ... is solved with the appropriate damped boundary conditions using impedance methods. The resonance frequency of a PZT immersed in ...
Electric impedance tomography market is expected to gain market growth in the forecast period of 2020 to 2027. Data Bridge ... Global Electric Impedance Tomography Market Scope and Market Size. Electric impedance tomography market is segmented on the ... An international Electric Impedance Tomography report helps Electric Impedance Tomography industry in deciding upon various ... global-electric-impedance-tomography-market. Key Pointers Covered in Electric Impedance Tomography Market Industry Trends and ...
ORIGIN OF IMPEDANCE CHANGES RELATED TO LUNG PERFUSION IN ELECTRICAL IMPEDANCE TOMOGRAPHY in INTENSIVE CARE MEDICINE, vol 36, ...
Cytometers, Automated, Electrical Impedance. Definition : Automated cytometers that measure the change in electrical impedance ... The change in the impedance of the electrical path as the cells pass generates electrical pulses, which can be electronically ... Entry Terms : "Impedance Cytometers" , "Electrical Impedance Cytometers" , "Coulter Cytometers" , "Coulter Cell Counters" ...
glossary:electrical_impedance. Also known as impedance. (electricity) The total opposition that a circuit presents to an ... glossary/electrical_impedance.txt · Last modified: 2012/10/16 14:40 (external edit) ... Also known as complex impedance. The ratio of the maximum voltage in an alternating-current circuit to the maximum current; ...
Jarvis, S. S., & Pawelczyk, J. A. (2009). Identification of the human electrical impedance indifferent point: A surrogate for ... Jarvis, Sara S. ; Pawelczyk, James A. / Identification of the human electrical impedance indifferent point : A surrogate for ... Identification of the human electrical impedance indifferent point: A surrogate for the volume indifferent point? European ... Jarvis, SS & Pawelczyk, JA 2009, Identification of the human electrical impedance indifferent point: A surrogate for the ...
... the impedance measurements to determine the impedance of at least one of the lungs substantially independently of impedance of ... using the leads and the case to acquire at least a first and a second impedance measurement responsive to impedance of the ... A method of determining an impedance of at least one lung of a patient having an implanted pacemaker that comprises first and ... Electrical impedance tomography to control electroporation. US6473640 *. 20 Jan 2000. 29 Oct 2002. Jay Erlebacher. Implantable ...
a b c d e f g h i Brown B.H. (2003) "Electrical Impedance Tomography (EIT) - A Review". J. Med. Eng. Technol. 27(3): 97-108. ... a b c d e f g h i Holder D.S., Electrical Impedance Tomography: Methods, History and Applications, Institute of Physics, 2004. ... Electrical impedance tomography (EIT) is a noninvasive type of medical imaging in which the electrical conductivity, ... a b c d e f g Bodenstein M., David M., Markstaller K. (2009) "Principles of electrical impedance tomography and its clinical ...
... loudspeakers High impedance Immittance Impedance bridging Impedance cardiography Impedance control Impedance matching Impedance ... Bioelectrical impedance analysis Characteristic impedance Electrical characteristics of dynamic ... to rapidly measure the electrical impedance of various electrical devices. The LCR meter (Inductance (L), Capacitance (C), and ... a calibrated reference impedance is adjusted to balance off the effect of the impedance of the device under test. Impedance ...
Electrical impedance myography, or EIM, is a non-invasive technique for the assessment of muscle health that is based on the ... Interest in electrical impedance dates back to the turn of the 20th century, when physiologist Louis Lapicque postulated an ... Electrical impedance of muscle tissue is anisotropic; current flowing parallel to muscle fibers flows differently from current ... Standard bioelectrical impedance analysis (BIA), like EIM, also employs a weak, high frequency electric current to measure ...
Further adjustment of the electrical conductivity may also be achieved by varying the conductivity of individual fibers ... and electrical shunt means disposed along the conductive material for causing more uniform resistivity between any two equally ... A flexible transcutaneous electrical nerve and/or muscle stimulation electrode is provided which utilizes a conductive material ... spaced apart points on the conductive material than without the electrical shunt means. ...
In electrical impedance tomography (EIT), various image reconstruction algorithms have been used in order to compute the ... internal resistivity distribution of the unknown object with its electric... ... Genetic Algorithm Electrical Impedance Tomography Resistivity Distribution Mesh Group Resistivity Profile These keywords were ... In electrical impedance tomography (EIT), various image reconstruction algorithms have been used in order to compute the ...
... with the factorization method to derive a new non-iterative algorithm for the detection of inclusions in electrical impedance ... In this work we study localized electric potentials that have an arbitrarily high energy on some given subset of a domain and ... Localized potentials in electrical impedance tomography. Bastian Gebauer 1, 1. Institut für Mathematik, Johannes Gutenberg- ... Keywords: Electrical impedance tomography, factorization method., Calderon problem. Mathematics Subject Classification: 35J25, ...
A. Abbasi, B. V. Vahdat and G. E. Fakhim, An inverse solution for 2D electrical impedance tomography based on electrical ... A. Abbasi, B. V. Vahdat and G. E. Fakhim, An inverse solution for 2D electrical impedance tomography based on electrical ... Electrical impedance tomography with multiplicative regularization. Ke Zhang 1, , Maokun Li 1,, , Fan Yang 1, , Shenheng Xu 1, ... D. Liu, A. K. Khambampati and J. Du, A parametric level set method for electrical impedance tomography, IEEE Trans. Med. Imag. ...
Cell based impedance sensing is becoming a new biophysical and cellular technology in cell based analyses. The technology has ... Application of Electric Cell-Substrate Impedance Sensing in Evaluation of Traditional Medicine on the Cellular Functions of ... Electrical Cell-Substrate Impedance Sensing for Measuring Cellular Transformation, Migration, Invasion, and Anticancer Compound ... Electric Cell-Substrate Impedance Sensing as a Screening Tool for Wound Healing Agents ...
Few effective technologies exist for sensing in dark or murky underwater situations. For this reason, we have been exploring the use of a novel biologicall
Electrical Impedance Test for Cervical Cancer Developed. April 21st, 2005 Editors Ob/Gyn ... Studies using an electrical impedance probe indicate that early tissue cell abnormalities can be immediately identified, ... In tissue cells, low frequency electrical currents travel around cells and can inform doctors of cell shapes and how they are ...
To test whether electrical skin impedance at each of three acupuncture points (APs) is significantly lower than at nearby sites ... Electric Conductivity. Electric Impedance / classification*. Female. Galvanic Skin Response*. Humans. Male. Meridians / ... OBJECTIVES: To test whether electrical skin impedance at each of three acupuncture points (APs) is significantly lower than at ... Impedance values at APs were not significantly less than at MPs or NPs. Impedance values at MPs were also not significantly ...
Magnetic resonance driven electrical impedance tomography: a simulation study.. Negishi M1, Tong T, Constable RT. ... Magnetic resonance electrical impedance tomography (MREIT) is a method for reconstructing a three-dimensional image of the ... In this paper, we present a new method called magnetic resonance driven electrical impedance tomography (MRDEIT), where the ... a vector wave equation for the electric field is used as the basis of the analysis instead of a quasi-static approximation. ...
Airway Closure Could Be Confirmed by Electrical Impedance Tomography.. Sun XM1, Chen GQ1, Zhou YM1, Yang YL2, Zhou JX1. ... 2 Beijing Electric Power Hospital, Capital Medical University Beijing, China.. Comment on. *Airway Closure in Acute Respiratory ...
Development of an Anatomically Realistic Forward Solver for Thoracic Electrical Impedance Tomography. Fei Yang,1 Jie Zhang,2 ... M. J. Moskowitz, T. P. Ryan, K. D. Paulsen, and S. E. Mitchell, "Clinical implementation of electrical impedance tomography ... I. Frerichs, J. Scholz, and N. Weiler, "10: electrical impedance tomography and its perspectives in intensive care medicine," ... electric impedance tomography versus gamma scintigraphy," Clinical Nutrition, vol. 25, no. 4, pp. 671-680, 2006. View at ...
VENTILATION INHOMOGENEITY ANALYSIS USING ELECTRICAL IMPEDANCE TOMOGRAPHY IMAGE PROCESSING. Syedah Sadaf Zehra, Inam Ul Ahad , ... a validation study on electrical impedancetomography, Am J Respir Crit Care Med. 169(7), 2004,791-800 ...
Establishing Muscle Impedance Parameters With Electrical Impedance Myography. The safety and scientific validity of this study ... Device: electrical impedance myography (EIM) EIM is a measure of impedance. EIM is a measure of the obstruction of flow of ... Device: electrical impedance myography (EIM) EIM is a measure of impedance. EIM is a measure of the obstruction of flow of ... Application of Electrical Impedance Myography (EIM) to Establish Muscle Impedance Parameters as a Potential Biomarker of ...
... provides functional images of an electrical conductivity distribution inside the human body. Since the 1980s, many po ...
The Factorization Method for Electrical Impedance Tomography Data from a New Planar Device. Mustapha Azzouz,1 Martin Hanke,2 ... Mustapha Azzouz, Martin Hanke, Chantal Oesterlein, and Karl Schilcher, "The Factorization Method for Electrical Impedance ...
Data collected using scalp electrode in humans matched known tissue impedance spectra and was stable over frequency. The ... A highly versatile Electrical Impedance Tomography (EIT) system, nicknamed the ScouseTom, has been developed. The system allows ... Electrical Impedance Tomography; brain imaging; long term monitoring; evoked activity; open source hardware; Arduino Electrical ... A Versatile and Reproducible Multi-Frequency Electrical Impedance Tomography System. James Avery * , Thomas Dowrick. ...
electric stress exceeds 500 kV/m.. Soil Ionization starts at field strengths above 300 kV/m.. Strength=(400+710 t-0.75) kV/m (8 ... Surge impedance coupling from driven (OHGW) to. In the time after the adjacent-tower reflection, from 3 to. undriven (phase) ... Surge impedance coupling, modified by. 6. CALCULATION OF CRITICAL CURRENT. using the geometric mean of the corona and geometric ... electrical strength of insulator combinations such as wood [7] W. Janischewskyj, W.A.Chisholm and J. Beattie,LightningGround. ...
In electrical impedance tomography the electrical conductivity inside a physical body is computed from electro-static boundary ... In electrical impedance tomography the electrical conductivity inside a physical body is computed from electro-static boundary ... 3D reconstruction for partial data electrical impedance tomography using a sparsity prior. Henrik Garde 1, and Kim Knudsen 2, ... H. Garde and K. Knudsen, Sparsity prior for electrical impedance tomography with partial data,, Inverse Probl. Sci. Eng., (2015 ...
Development of electrical impedance tomography of microwave ablation Author(s): A. McEwan; H. Wi; D. T. Nguyen; P. Jones; V. ... 208 tetrapolar electrical impedance measurements were obtained at 30 frame/s from a 16 electrode EIT system. In the porcine ... In this study we assess the feasibility of electrical impedance tomography (EIT) to track the temperature changes during ... model ventilation artefact was removed by low pass filtering and successful ablation related impedance change image sequences ...
... electrical engineering) abbreviated? MB-IIN stands for Multi-Band Impedance Inverter Network (electrical engineering). MB-IIN ... is defined as Multi-Band Impedance Inverter Network (electrical engineering) rarely. ... a href=https://www.acronymfinder.com/Multi_Band-Impedance-Inverter-Network-(electrical-engineering)-(MB_IIN).html,MB-IIN,/a, ... S.v. "MB-IIN." Retrieved October 22 2020 from https://www.acronymfinder.com/Multi_Band-Impedance-Inverter-Network-(electrical- ...
For the two dimensional inverse electrical impedance problem in the case of piecewise constant conductivities with the currents ... Electrical impedance tomography using a point electrode inverse scheme for complete electrode data. Fabrice Delbary 1, and ... Keywords: boundary integral equations, Newton scheme., Electrical impedance tomography, point electrode model, complete ... F. Delbary and R. Kress, Electrical impedance tomography with point electrodes,, J. Integral Equations Appl., 22 (2010), 193. ...
Postdoc in MR Electric Impedance Tomography for Dose Control of Transcranial Electric Stimulation DTU Health Tech Share on ... Postdoc in MR Electric Impedance Tomography for Dose Control of Transcranial Electric Stimulation ... We are seeking a highly motivated Postdoc candidate to work on novel reconstruction methods for MR Electric Impedance ... overarching aim in this project is to leverage our recently developed MREIT methods and FEM models of the TDCS-induced electric ...
Electrical Impedance Tomography of Neonatal Brain Activity A T Tidswell ; A T Tidswell ... A T Tidswell, JS Wyatt, RH Bayford, DS Holder; Electrical Impedance Tomography of Neonatal Brain Activity. Clin Sci (Lond) 1 ... Detection of Changes in Intrathoracic Fluid in Man Using Electrical Impedance Tomography Clin Sci (Lond) (July,1994) ...
Key Words: Electrical impedance tomography, prostate cancer, surgical margin assessment, radical prostatectomy ... Towards Microendoscopic Electrical Impedance Tomography for Intraoperative Surgical Margin Assessment Featured Articles ... we have developed a novel Microendoscopic Electrical Impedance Tomography (EIT) probe that can be introduced into the surgical ... Significantly different electrical property signatures have been observed between benign and malignant prostate tissues, and we ...
Electrical impedance myography (EIM) is a technique for the evaluation of neuromuscular diseases, including amyotrophic lateral ... Optimizing Electrode Configuration for Electrical Impedance Measurements of Muscle via the Finite Element Method. Author(s). ... "Optimizing Electrode Configuration for Electrical Impedance Measurements of Muscle via the Finite Element Method." IEEE Trans. ...
  • The final section is an abbreviated summary of the 1994 National Institutes of Health (NIH) Technology Assessment Conference on Bioelectrical Impedance Analysis in Body Composition Measurement. (nap.edu)
  • The Portable Impedance Meter system lends itself well to the measurement of acoustic properties of aircraft interiors and trim materials. (thefreedictionary.com)
  • Chip-based impedance measurement on s. (ugent.be)
  • Chip-based impedance measurement on single cells for monitoring sub-toxic effects on cell membranes," BIOSENSORS & BIOELECTRONICS , vol. 26, no. 8, pp. 3405-3412, 2011. (ugent.be)
  • For this purpose, an impedance measurement technique using nickel comb capacitors was used. (pollub.pl)
  • Gold impedance electrodes have been successfully fabricated for impedance measurement on cells cultured on the electrode surface which was modified with the fabrication of gold nanopillars. (ucc.ie)
  • The fabrication of the threedimensional structures on the interdigitated electrodes was supposed to improve the sensitivity of the ECIS (electric cell-substrate impedance sensing) measurement while monitoring the cytotoxicity effects of two different drugs (Antrodia Camphorata extract and Nicotine) on three different cell lines (HeLa, A549 and BALBc 3T3) cultured on the impedance devices and change the morphology of the cells growing on the nanostructured electrodes. (ucc.ie)
  • Electrical Impedance Tomography (EIT)is a technique based on the injection of small currents and voltage measurements using electrodes on the skin surface generating cross-sectional images representing impedance change in a slice of the thorax. (clinicaltrials.gov)
  • Bruel & Kjaer's Impedance Meter System provides aerospace engineers with a user-friendly system, suitable for carrying out research and production quality control impedance measurements, up to 150 dB SPL on engine nacelle liners. (thefreedictionary.com)
  • Impedance measurements obtained with the dead cells on the negative control electrodes or the test electrodes with the drugs can be compared to those done on the electrodes containing just media in the tested volume (as no cells are attached and cover the electrode surface). (ucc.ie)
  • Modelling the impact of altered axonal morphometry on the response of regenerative nervous tissue to electrical stimulation through macro-sieve electrodes. (uni-bielefeld.de)
  • The introduction of nanopillars on the impedance electrodes, however, did not improve much the sensitivity of the assay with the exception of tests carried out with Nicotine. (ucc.ie)
  • The impedance figures recorded using these electrodes were between 1.5kΩ and 2.5 kΩ, while the figures recorded on confluent cell layers range between 4kΩ and 5.5kΩ with peaks of almost 7 kΩ if there was more than one layer of cells growing on each other. (ucc.ie)
  • However, little or no differences were noticed in the impedance analysis carried out on the two different kinds of electrodes using cultured cells. (ucc.ie)
  • A window on the biology of the human body has opened as a result of numerous studies utilizing bioelectrical impedance. (nap.edu)
  • The view from this window is affected by the previous and current works of human biologists and biomedical engineers and by the future potential of bioelectrical impedance. (nap.edu)
  • This article briefly describes the research history of bioelectrical impedance, the status of present research related to body composition and future research directions. (nap.edu)
  • The phase angle (see Figure 7-1 ), which has been found to be important for describing relationships between bioelectrical impedance and the body and for measuring physiological variables (Baumgartner et al. (nap.edu)
  • In his office, he uses a bioelectrical impedance meter to measure skeletal muscle versus fat tissue mass, from which calculations can be made for the number of calories per day required to reduce weight in a certain period of time. (thefreedictionary.com)
  • We aimed to quantify the association between total body fat (measured by bioelectrical impedance) and risk of BO and examine if this association was modified by gastro-oesophageal reflux (GOR) and abdominal obesity. (edu.au)
  • Bioelectrical impedance analysis (BIA) has received significant attention as a means of studying body composition and the relationship of changes in the body's conductive and other electrical properties to changes in body water or its distribution. (elsevier.com)
  • Jacobs, DO 1997, ' Bioelectrical impedance analysis: Implications for clinical practice ', Nutrition in Clinical Practice , vol. 12, no. 5, pp. 204-210. (elsevier.com)
  • Arndt S., Seebach J., Psathaki K., Galla H.J., Wegener J.: Bioelectrical Impedance Assay to Monitor Changes in Cell Shape during Apoptosis. (pollub.pl)
  • Bagnaninchi P.O., Drummond N.: Real-Time Label-Free Monitoring of Adipose-Derived Stem Cell Differentiation with Electric Cell-Substrate Impedance Sensing. (pollub.pl)
  • Hong J., Kandasamy K., Marimuthu M., Choi M.S., Kim S.: Electrical Cell-Substrate Impedance Sensing as a Non-Invasive Tool for Cancer Cell Study. (pollub.pl)
  • Xiao C., Luong J.H.T.: On-Line Monitoring of Cell Growth and Cytotoxicity Using Electric Cell-Substrate Impedance Sensing (ECIS). (pollub.pl)
  • A measure of impedance (Z) is composed of the sum of two vectors, resistance (R) and reactance (Xc), measured at a particular frequency and is described mathematically by the equation Z 2 = R 2 + Xc 2 . (nap.edu)
  • FIGURE 7-1 Impedance plot curve of resistance and reactance with frequency. (nap.edu)
  • Impedance is the frequency-dependent opposition of a conductor to the flow of an alternating electric current. (nap.edu)
  • The aim of the study was to present a method for assessing the condition of cell culture by measuring the impedance of cells cultured in the presence of nickel. (pollub.pl)
  • Resistance is the opposition of a conductor to the alternating current, and as the electric current travels through the body, resistance is basically the same as in nonbiological conductors (Kay et al. (nap.edu)
  • Arias L.R., Carla A.P., Yang L.: Real-Time Electrical Impedance Detection of Cellular Activities of Oral Cancer Cells. (pollub.pl)
  • This thesis work covered the fabrication and characterisation of impedance sensors for biological applications aiming in particular to the cytotoxicity monitoring of cultured cells exposed to different kind of chemical compounds and drugs and to the identification of different types of biological tissue (fat, muscles, nerves) using a sensor fabricated on the tip of a commercially available needle during peripheral nerve block procedures. (ucc.ie)
  • Fingerprint Dive into the research topics of 'Identification of the human electrical impedance indifferent point: A surrogate for the volume indifferent point? (elsevier.com)
  • To analyze the Electric Impedance Tomography Market based on various factors- price analysis, supply chain analysis, porter five force analyses, etc. (pharmiweb.com)
  • Glidewell, M., Ng, K.T.: Anatomically Constrained Electrical Impedance Tomography for Anisotropic Bodies Via a Two-step Approach. (springer.com)
  • R. P. Henderson and J. G. Webster, "Impedance camera for spatially specific measurements of thorax," IEEE Transactions on Biomedical Engineering , vol. 25, no. 3, pp. 250-254, 1978. (hindawi.com)
  • This paper discusses the electric circuit simulation method in the inverse and direct problems in electrical impedance tomography. (bath.ac.uk)
  • This thesis investigates the impact of changing the boundary value problems in Electrical Impedance tomography from Neumann-to-Dirichlet to Robin-to-Dirichlet. (clemson.edu)
  • The method is illustrated with one typical nonlinear inverse problem, electrical impedance tomography with complete electrode model, under sparsity constraints. (osti.gov)
  • An instrumental electrode model (IEM) capable of describing the performance of electrical impedance tomography (EIT) systems in the MHz frequency range has been proposed. (strath.ac.uk)
  • Like all impedance-based methods, EIM hinges on a simplified model of muscle tissue as an RC circuit. (wikipedia.org)
  • EIM captures these changes in the tissue as a whole by measuring its impedance characteristics across multiple frequencies and at multiple angles relative to the major muscle fiber direction. (wikipedia.org)
  • Studies using an electrical impedance probe indicate that early tissue cell abnormalities can be immediately identified, effectively meaning that women could be sent for further investigation and treatment much more quickly. (medgadget.com)
  • In tissue cells, low frequency electrical currents travel around cells and can inform doctors of cell shapes and how they are arranged. (medgadget.com)
  • Because of electrical impedance of the pulmonal tissue is dependant to the air content, the air distribution within the lung over a certain period can be monitored. (clinicaltrials.gov)
  • Data collected using scalp electrode in humans matched known tissue impedance spectra and was stable over frequency. (mdpi.com)
  • Past studies have suggested that acupuncture meridians are physiologically characterized by low electrical impedance and anatomically associated with connective tissue planes. (harvard.edu)
  • Methods/Results: In 28 healthy subjects, we assessed electrical impedance of skin and underlying subcutaneous connective tissue using a four needle-electrode approach. (harvard.edu)
  • This phenomenon jeopardizes the device biocompatibility, because it encapsulates the stimulation lead with an "insulating" tissue, creating adherences along the lead and often leading to an increase of the stimulation threshold over time and a larger electrical consumption. (archives-ouvertes.fr)
  • Implantable medical electrical stimulation and/or sensing leads (electrical medical leads) are well known in the fields of tissue stimulation and monitoring, including cardiac pacing and cardioversion/defibrillation, and in other fields of electrical stimulation or monitoring of electrical signals or other physiologic parameters. (google.com)
  • Electrical impedance measurements were performed on 13 atherosclerotic human aortic segments at 67 measuring spots in order to determine whether or not on the basis of these data a distinction can be made between atherosclerotic lesions and normal tissue. (eur.nl)
  • We hypothesized that segments of acupuncture meridians that are associated with loose connective tissue planes (between muscles or between muscle and bone) visible by ultrasound have greater electrical conductance (less electrical impedance) than non-meridian, parallel control segments. (biomedcentral.com)
  • Tissue impedance between the two inner needles was calculated based on Ohm's law (ratio of voltage to current intensity). (biomedcentral.com)
  • At the Pericardium location, mean tissue impedance was significantly lower at meridian segments (70.4 ± 5.7 Ω) compared with control segments (75.0 ± 5.9 Ω) ( p = 0.0003). (biomedcentral.com)
  • Tissue impedance was on average lower along the Pericardium meridian, but not along the Spleen meridian, compared with their respective controls. (biomedcentral.com)
  • Ultrasound imaging of meridian and control segments suggested that contact of the needle with connective tissue may explain the decrease in electrical impedance noted at the Pericardium meridian. (biomedcentral.com)
  • Further studies are needed to determine whether tissue impedance is lower in (1) connective tissue in general compared with muscle and (2) meridian-associated vs. non meridian-associated connective tissue. (biomedcentral.com)
  • 10. Why is the measured impedance of the bladder tissue different from the computational modelling results? (ellibs.com)
  • This review focuses on clarifying the various processes starting from the tissue electrical properties, through to diagnostic EIT measures, in order to support accurate interpretation of EIT results. (embs.org)
  • The frequencies used depend on the application, and their selection depends on the frequency behaviour of the impedance for the target tissue. (elsevier.com)
  • 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 two-compartment coaxial cylindrical model composed of the aorta and its surrounding thoracic tissues. (biomedsearch.com)
  • Tomsin K, Mesens T, Molenberghs G, Gyselaers W (2011) Diurnal and position-induced variability of impedance cardiography measurements in healthy subjects. (springer.com)
  • In electrical impedance tomography (EIT), various image reconstruction algorithms have been used in order to compute the internal resistivity distribution of the unknown object with its electric potential data at the boundary. (springer.com)
  • The resulting one-dimensional governing equation of motion, which includes the effect of damping, is solved with the appropriate damped boundary conditions using impedance methods. (spie.org)
  • Electrical impedance tomography (EIT) is an imaging technique that reconstructs the internal electrical properties of an object from boundary voltage measurements. (mcmaster.ca)
  • TY - JOUR T1 - Reconstruction of Small Inclusions in Electrical Impedance Tomography Problems JO - East Asian Journal on Applied Mathematics VL - 2 SP - 280 EP - 294 PY - 2019 DA - 2019/03 SN - 9 DO - http://doi.org/10.4208/eajam.030518.210918 UR - https://global-sci.org/intro/article_detail/eajam/13083.html KW - Electrical impedance tomography, small inclusion, inverse problem, uniqueness. (global-sci.org)
  • A: International Conference on Electrical Bioimpedance. (upc.edu)
  • This is a combined conference for the XIV th International Conference on Electrical Bioimpedance and the 11th Conference on Biomedical Applications of EIT. (eit.org.uk)
  • A flexible transcutaneous electrical nerve and/or muscle stimulation electrode is provided which utilizes a conductive material, preferably a conductive fabric, and electrical shunt means disposed along the conductive material for causing more uniform resistivity between any two equally spaced apart. (google.com)
  • Raaijmakers E, Marcus JT, Goovaerts HG, De Vries PMJM, Faes TJC, Heethaar RM (1996) The influence of pulsatile flow on blood resistivity in impedance cardiograp. (springer.com)
  • The latter application is illustrated with estimation of the resistivity of gelatin using an electrical impedance tomography setup. (scirp.org)
  • 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. (biomedcentral.com)
  • Explicit characterization of inclusions in electrical impedance tomography ," SIAM Journal on Mathematical Analysis, Vol. (thefreedictionary.com)
  • The in vitro part presents the electrical characterization, using impedance measurements, in parallel to the biological characterization, using immunocytochemistry, of a cellular fibrosis model. (archives-ouvertes.fr)
  • After a statistical analysis, the impedance values show a significantly different signature for cultures with growth factor, with respect to sham cultures, while the biological characterization confirmed the presence of more activated and differentiated cells over time. (archives-ouvertes.fr)
  • Cell based impedance sensing is becoming a new biophysical and cellular technology in cell based analyses. (springer.com)
  • We used a commercial impedance sensing device (ECIS®) to assess the migration of the cells following irradiation. (aps.org)
  • This paper demonstrates the spatial sensing capability of an inkjet-printed carbon nanotube (CNT) thin film upon a crack?s fracture behavior via electrical impedance tomography (EIT). (uni-linz.ac.at)
  • Impedance changes in lung ventilation are investigated in mechanically ventilated patients who routinely undergo bronchoscopy in intensive care medicine. (clinicaltrials.gov)
  • In the porcine model ventilation artefact was removed by low pass filtering and successful ablation related impedance change image sequences were reconstructed from four of nine liver ablations. (spie.org)
  • The provision of guidance in ventilator therapy by continuous monitoring of regional lung ventilation, aeration and respiratory system mechanics is the main clinical benefit of electrical impedance to. (bioportfolio.com)
  • Electrical impedance tomography (EIT) is a noninvasive tool that allows real-time imaging of regional ventilation. (ovid.com)
  • Electrical impedance tomography (EIT) is a noninvasive, radiation-free monitoring tool that provides real-time imaging of ventilation at the bedside. (scielo.br)
  • We present a case in which monitoring of trans-pulmonary pressure and ventilation distribution using Electrical Impedance Tomography (EIT) provided essential information for preventing VILI. (eur.nl)
  • In 15 patients with early, mild, diffuse acute respiratory distress syndrome, application of an open lung approach ( vs. a standard management protocol that does not target an "open" lung) resulted in lower driving pressure, improved oxygenation, and more homogeneous distribution of ventilation (assessed by electric impedance tomography). (asahq.org)
  • Russo, Stefania , Carbonaro, Nicola , Tognetti, Alessandro and Nefti-Meziani, Samia A Quantitative Evaluation of Drive Patterns in Electrical Impedance Tomography , in: MOBIHEALTH 2016 - 6th EAI International Conference on Wireless Mobile Communication and Healthcare, November 14-16 2016, Milan. (salford.ac.uk)
  • To apply electrical impedance tomography (EIT) and the new evaluation approach (the functional EIT) in monitoring the development of artificial lung injury. (semanticscholar.org)
  • Kubicek WG, Karnegis JN, Patterson RP, Witsoe DA, Mattson RH (1966) Development and evaluation of an impedance cardiac output system. (springer.com)
  • The aim of this protocol is to offer a generally applicable guide for the usage of this particular type of impedance based cellular assays and provide protocols for some of the key functions from the constantly growing number of applications. (jove.com)
  • Electrical skin impedance at acupuncture points. (biomedsearch.com)
  • OBJECTIVES: To test whether electrical skin impedance at each of three acupuncture points (APs) is significantly lower than at nearby sites on the meridian (MP) and off the meridian (NP). (biomedsearch.com)
  • CONCLUSIONS: Within the reliability limits of our study methods, none of the three APs tested has lower skin impedance than at either of the nearby control points. (biomedsearch.com)
  • These results are not consistent with previous studies that detected lower skin impedance at APs than nearby sites. (biomedsearch.com)
  • Further study is necessary to determine whether MPs have lower skin impedance than nearby NPs. (biomedsearch.com)
  • We are seeking a highly motivated Postdoc candidate to work on novel reconstruction methods for MR Electric Impedance Tomography (MREIT). (dtu.dk)
  • The multiplicative regularization scheme is applied to three-dimensional electrical impedance tomography (EIT) image reconstruction problem to alleviate its ill-posedness. (bioportfolio.com)
  • This brings us to the main question of our project: does the fibrosis developing around the cardiac leads have an electrical signature?My thesis work is organized along three axes. (archives-ouvertes.fr)
  • Respiratory mechanics, gas exchange, electrical impedance tomography (EIT), cardiac index, and stroke volume variation were measured at baseline and 20 min after OLA implementation (post-OLA). (asahq.org)
  • M. Brühl and M. Hanke, Numerical implementation of two noniterative methods for locating inclusions by impedance tomography ,, Inverse Problems , 16 (2000), 1029. (aimsciences.org)
  • The overarching aim in this project is to leverage our recently developed MREIT methods and FEM models of the TDCS-induced electric fields (www.simnibs.org) to quantify the physical stimulation strength of TDCS in the brain at the individual level. (dtu.dk)
  • Development of methods for electrical impedance tomography of epileptic seizures. (ucl.ac.uk)
  • L. Afraites, M. Dambrine and D. Kateb, On second order shape optimization methods for electrical impedance tomography. (esaim-cocv.org)
  • W. Lionheart, N. Polydorides and A. Borsic, Electrical impedance tomography: methods, history and applications, edited by D.S. Holder. (esaim-cocv.org)
  • By considering sedimentation layers with different electrical properties, non-invasive methods such as electrical impedance tomography (EIT) can be used to estimate the settling curves and velocities. (gla.ac.uk)
  • The goal of this feasibility study is to evaluate the ability of Electrical Impedance Tomography (EIT) for providing regional and quantitative information about the extent and nature of br. (bioportfolio.com)
  • Gaw RL, Cornish BH, Thomas BJ (2007) Comparison of a theoretical impedance model with experimental measurements of pulsatile blood flow. (springer.com)
  • The electrical resistance is calculated using Ohm's law, which allows a numerical description of the quality of the cell barrier. (jove.com)
  • Gaw RL, Cornish BH, Thomas BJ (2008) The electrical impedance of pulsatile blood flowing through rigid tubes: a theoretical investigation. (springer.com)
  • Frerichs and Zhao noted that, although in the task force electrical impedance tomography (EIT) was considered among the imaging techniques used in acute respiratory failure, no related articles were reported in the final paper. (ersjournals.com)
  • Is electrical impedance tomography ready for clinical use in acute respiratory failure? (ersjournals.com)
  • The purpose of this study is to evaluate the Genesis Electrical Impedance Tomography (EIT) imaging system for use in pediatric respiratory disease populations including neuromuscular and b. (bioportfolio.com)
  • Electrical impedance tomography is a viable technology for use in paediatric critical respiratory failure. (bmj.com)
  • 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. (aimsciences.org)
  • B. Gebauer and N. Hyvönen, Factorization method and irregular inclusions in electrical impedance tomography ,, Inverse Problems , 23 (2007), 2159. (aimsciences.org)
  • A novel method for the imaging of static scenes using Electrical Impedance Tomography (EIT) is reported with implementation and validation using numerical and phantom models. (bioportfolio.com)
  • Electrical impedance scanning (EIS) is a new adjunctive diagnostic method for women breast cancer examination. (eurekamag.com)
  • We used a four-electrode method to measure the electrical impedance along segments of the Pericardium and Spleen meridians and corresponding parallel control segments in 23 human subjects. (biomedcentral.com)
  • A method includes storing baseline data representing at least one local or global electrical characteristics for at least a portion of a region of interest. (patents.com)
  • K. Eppler and H. Harbrecht, A regularized Newton method in electrical impedance tomography using shape Hessian information. (esaim-cocv.org)
  • We validated, by means of allometric relationships and root severing experiments, the modified earth impedance method developed for measuring absorbing root surfaces. (oup.com)
  • To correlate the data obtained by Electrical impedance tomography (EIT) during the spontaneous breathing trials (SBT) on a T-piece, in children, with failure in the trial and Extubation failure. (clinicaltrials.gov)
  • Combined ultrasound and electrical impedance tomography (EIT) puts 3-D ultrasound imaging together with EIT data in a co-registered volume. (dartmouth.edu)
  • EIT relies on the mathematical processing of impedance data collected non-invasively from patients to reconstruct the 3-D distribution of the electrical properties of the tissues inside the patient. (dartmouth.edu)
  • For an enhanced user experience of this Electric Impedance Tomography Market report, all the facts and figures of statistical and numerical data are represented very well throughout the report. (pharmiweb.com)
  • The impedance data is used for mapping and correlation with a phenomenon of interest. (eliko.ee)
  • The notion of impedance is useful for performing AC analysis of electrical networks, because it allows relating sinusoidal voltages and currents by a simple linear law. (wikipedia.org)
  • In multiple port networks, the two-terminal definition of impedance is inadequate, but the complex voltages at the ports and the currents flowing through them are still linearly related by the impedance matrix. (wikipedia.org)
  • The introduction of the concept of impedance in AC circuit is justified by the fact that there are two additional impeding mechanisms to be taken into account besides the normal resistance of DC circuits: the induction of voltages in conductors self-induced by the magnetic fields of currents (inductance), and the electrostatic storage of charge induced by voltages between conductors (capacitance). (wikipedia.org)
  • Muscle composition and microscopic structure change with disease, and EIM measures alterations in impedance that occur as a result of disease pathology. (wikipedia.org)
  • Bio-electrical Impedance Analysis (BIA) is a simple painless procedure which enables a doctor or healthcare provider to analyze the amounts of fat, muscle and water in the body. (thebody.com)
  • These include static impedance and dynamic impedance (i.e., tympanometry and impedance tests in conjunction with intra-aural muscle reflex elicitation). (bioportfolio.com)