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A new system for measuring electrical conductivity of water as a function of admittance

Introduction The electrical conductivity (EC) of a water solution is a measure of how much material is dissolved in the water. EC is an important electrochemical water quality parameter. However, except for drinking water, EC alone is not adequate to characterize water. It has been suggested that drinking water quality can be checked effectively by measuring the conductivity of the water [ 1 ]. EC is usually measured by a probe that applies voltage between two electrodes and records the drop in voltage. This drop reflects the resistance of the water, which is

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Development of a real-time, semi-capacitive impedance phlebography device

Introduction One of the most common diseases is the chronic venous insufficiency (CVI) of the lower extremities, which is caused by a permanent pressure overload of the vein. The venous tree is defective, incapable of removing sufficient amounts of blood from the peripheral veins. This causes pooling of blood and intravascular fluid at the lower gravitational parts of the body - the legs. CVI may affect up to 20% of adults and as much as 1.5% to 2 %of the annual healthcare budgets in European countries are spent on the management of CVI [ 1 , 2 ]. Most

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A system to monitor segmental intracellular, interstitial, and intravascular volume and circulatory changes during acute hemodialysis

unit). The Z-Spec-2 provides a “scheduler” capability that can be used to operate the instrument continuously as either an IPG or an BIS or any desired time sequenced combination of the two modes. The Z-Spec-2 includes a Lead I electrocardiographic (ECG) and a photoelectric plethysmographic (PPG) analog channel (via external transducers) which provide measures that are used to quantify segmental blood flow. A built-in 16 bit microcontroller is responsible for management of all Z-Spec-2 functions. Figure 4 shows the basic functional block diagram of our Z

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The feasibility of using compression bioimpedance measurements to quantify peripheral edema

develops hypotension or cramping) and subjective instead of goal-directed and quantitative to achieve defined targets based on validated measures. Several other quantitative methods for dry weight determination have been proposed including the use of biochemical parameters, monitoring changes in inferior vena cava diameter, and the use of BIS measurements [ 10 ]. In addition, in the CHF setting, monitored approaches to disease management have shown positive outcomes [ 11 ]. In both cardiovascular and renal diseases, the clinical care and financial burdens make

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Monitoring thoracic fluid content using bioelectrical impedance spectroscopy and Cole modeling

The aim of this study was to identify BIS measures, which can be derived based on the Cole model, that are sensitive to early stages of thoracic fluid accumulation. We simulated this medical condition in healthy subjects by shifting a part of the whole blood from the periphery towards the thorax. The redistribution of blood was achieved non-invasively through leg compression using inflatable leg sleeves. We acquired BIS data before, during and after compression of the legs and examined the effect of thoracic fluid variations on parameters derived based on the

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Statistical methods for bioimpedance analysis

’s kappa provides a measure of association which is corrected for equal decisions due to chance. Which of these measures to report should be chosen based on how the measurements are to be used in the future. The same goes for the importance of the measurement performance. A certain degree of measurement error may be acceptable if measurements are to be used as an outcome in a comparative study such as a clinical trial, but the same errors may be unacceptably large in individual patient management such as screening or risk prediction [ 32 ]. For some applications, there

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Comparison of cerebrovascular reactivity tests: a pilot human study

Introduction Rheoencephalography This study compared cerebrovascular reactivity monitored by rheoencephalography (REG), a noninvasive continuous monitoring modality, to cerebrovascular reactivity measured by currently used neuromonitoring modalities: transcranial Doppler, near infrared spectroscopy and laser Doppler flowmetry. Jenkner [ 1 , 2 ] first applied the term rheoencephalography to electrical impedance plethysmography, when applied to the head to measure continuous registration of cerebrovascular changes. The technique was originally developed to

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Studies in Rheoencephalography (REG)

widely used in such nations as Austria, Italy, USA, Soviet Union/Russia, Poland, Belgium, Bulgaria, Hungary, China, and Spain. Following the development and computerization of neurological diagnostics and the wide use of a variety of brain mapping methods, interest in REG declined because of uncertainty about what aspects of brain circulation REG measures. An impedance brain scanner was mentioned in a 1978 publication [ 1 ], but no impedance scanner device was reported as being manufactured or applied to clinical practice. Currently no manufacturer has registered a REG

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Electrodermal activity responses for quantitative assessment of felt pain

of felt pain strength is a key factor for successful pain management during surgery and other clinical procedures. Presently, most of the pain scoring systems used in clinical practice rely on patient cooperation and attentiveness. However, in some cases, for example in unconscious, confused, uncooperative patients, or in the case for infants, questioning is impossible. As a result, pain is usually poorly evaluated and inadequately managed. Therefore, a more practical, patient-independent method for this purpose is highly desirable. As pain provokes a sympathetic

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Impedimetric characterization of human blood using three-electrode based ECIS devices

by Laboratory Methods, WB Saunders Company, Philadelphia, PA. 1979;1:60. Henry JB Clinical Diagnosis and Management by Laboratory Methods WB Saunders Company Philadelphia, PA 1979 1 60 27 Thavasu PW, Longhurst S, Joel SP, Slevin ML, Balkwill FR. Measuring cytokine levels in blood: Importance of anticoagulants, processing, and storage conditions. J. Immunol. Methods. 1992;153(1-2):115-4. http://dx.doi.org/10.1016/0022-1759(92)90313-I 10.1016/0022-1759(92)90313-I 1381403 Thavasu PW Longhurst S Joel SP Slevin ML Balkwill FR

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