Static conductivity imaging using variational gradient Bz algorithm in magnetic resonance electrical impedance tomography.

abstract：UNLABELLED:The study created an 'ex vivo' model to test different algorithms for measurements of mucosal haemoglobin saturation with visible light spectrophotometry (VLS). The model allowed comparison between algorithms, but it also allowed comparison with co-oximetry using a 'gold standard' method. This has not been d...

journal_title：Physiological measurement

authors： Gade J,Greisen G

更新日期：2016-09-01 00:00:00

abstract：OBJECTIVE:Arterial CO2 (PaCO2) has a strong effect on cerebral blood flow (CBF), but its influence on CBF regulatory mechanisms and circulatory systemic variables has not been fully described over the entire physiological range of PaCO2. APPROACH:CBF velocity (CBFV, transcranial Doppler), blood pressure (BP, Finometer...

journal_title：Physiological measurement

authors： Minhas JS,Panerai RB,Robinson TG

更新日期：2018-06-19 00:00:00

abstract：:Automatic sleep stage classification with cardiorespiratory signals has attracted increasing attention. In contrast to the traditional manual scoring based on polysomnography, these signals can be measured using advanced unobtrusive techniques that are currently available, promising the application for personal and co...

journal_title：Physiological measurement

authors： Fonseca P,Long X,Radha M,Haakma R,Aarts RM,Rolink J

更新日期：2015-10-01 00:00:00

abstract：:A study of the concentrations of the common breath metabolites ammonia, acetone, isoprene, ethanol and acetaldehyde in the breath of five subjects over a period of 30 days has been carried out. Breath samples were taken and analysed in the early morning on arrival at the laboratory. The real time analyses of three con...

journal_title：Physiological measurement

authors： Diskin AM,Spanel P,Smith D

更新日期：2003-02-01 00:00:00

abstract：:Impedance cardiography (ICG) has been proposed to estimate the stroke volume (SV) and cardiac output (CO) in various medical indications. The aim of this study was to explore the reliability of ICG during pregnancy with respect to SV and CO measurements. Blood pressure, heart rate and thoracic impedance were monitored...

journal_title：Physiological measurement

authors： Moertl MG,Schlembach D,Papousek I,Hinghofer-Szalkay H,Weiss EM,Lang U,Lackner HK

更新日期：2012-06-01 00:00:00

abstract：:Current methods for analysing foetal heart rate (FHR) patterns have yet to meet their full potential in the recognition of hypoxia in the foetus. Following the recent suggestion that fractal analysis can be applied to FHR recordings, the current paper describes a method for distinguishing two simultaneous fractal dime...

journal_title：Physiological measurement

authors： Gough NA

更新日期：1993-08-01 00:00:00

abstract：:Remote sensing of the reflectance photoplethysmogram using a video camera typically positioned 1 m away from the patient's face is a promising method for monitoring the vital signs of patients without attaching any electrodes or sensors to them. Most of the papers in the literature on non-contact vital sign monitoring...

journal_title：Physiological measurement

authors： Tarassenko L,Villarroel M,Guazzi A,Jorge J,Clifton DA,Pugh C

更新日期：2014-05-01 00:00:00

abstract：:Cardiac output (CO) monitoring is not only essential for critically ill patients in the hospital, but also for patients at home and those undergoing cardiopulmonary exercise testing. However, CO is difficult to monitor during daily activities and exercise. In this paper, we aim at developing a novel CO estimation meth...

journal_title：Physiological measurement

authors： Wang L,Poon CC,Zhang YT

更新日期：2010-05-01 00:00:00

abstract：:The point spread function (PSF) is the most widely used tool for quantifying the spatial resolution of imaging systems. However, prerequisites for the proper use of this tool are linearity and space invariance. Because EIT is non-linear it is only possible to compare different reconstruction algorithms using a standar...

journal_title：Physiological measurement

authors： Ider YZ,Eyüboğlu BM,Kuzuoğlu M,Leblebïcïoğlu K,Baysal U,Cağlar BK,Bïrgül O

更新日期：1995-08-01 00:00:00

abstract：:This paper discusses some important issues for the design of electrical impedance measurement systems intended for body fluid shift monitoring, in particular during dialysis treatments. We have studied two common signal generation systems: digital synthesis and carrier recovery. We have found that in prolonged measure...

journal_title：Physiological measurement

authors： Lozano A,Rosell J,Pallás-Areny R

更新日期：1995-11-01 00:00:00

abstract：:Hand bone equivalent phantoms (250 ml) carrying selenium in various amounts were irradiated and counted for in vivo neutron activation analysis (IVNAA) by employing a 4π NaI(TI) based detection system. During the analysis of counting data, a feature at a higher energy than the gamma ray peak from (77m)Se (0.162 MeV) w...

journal_title：Physiological measurement

authors： Tahir SN,Chettle DR

更新日期：2015-12-01 00:00:00

abstract：:In this study, we developed a novel technique for estimating non-constrained and cuffless blood pressure (BP) that was based on electrocardiogram (ECG) and ballistocardiogram (BCG). The BCG was non-invasively measured using a common electronic weighing scale when a subject was standing on it. The ECG was measured usin...

journal_title：Physiological measurement

authors： Shin JH,Lee KM,Park KS

更新日期：2009-07-01 00:00:00

abstract：:In the clinical environment the reliable interpretation of EIT images depends on the quality of the data. In the electrically noisy hospital environment the system performance needs to be assessed for each clinical investigation. From the model of noise presented, a figure of merit for comparisons of system performanc...

journal_title：Physiological measurement

authors： Meeson S,Blott BH,Killingback AL

更新日期：1996-11-01 00:00:00

abstract：:Fetal motility is a widely accepted indicator of the well-being of a fetus. In previous research, it has be shown that fetal motion (FM) is coherent with fetal heart rate accelerations and an indicator for active/rest cycles of the fetus. The most common approach for FM and fetal heart rate (FHR) assessment is by Dopp...

journal_title：Physiological measurement

authors： Biglari H,Sameni R

更新日期：2016-11-01 00:00:00

abstract：:In this work, we describe a beat-by-beat method for assessing the clinical utility of pulsatile waveforms, primarily recorded from cardiovascular blood volume or pressure changes, concentrating on the photoplethysmogram (PPG). Physiological blood flow is nonstationary, with pulses changing in height, width and morphol...

journal_title：Physiological measurement

authors： Li Q,Clifford GD

更新日期：2012-09-01 00:00:00

abstract：:The purpose of this study was to examine the validity and reliability of estimated parameters of the work-time relationship during cross-country ski ergometry using the traditional multi-trial critical power (CP) test and a 3 min 'all-out' test (3MT). Fourteen recreationally active male participants (mean ± SD; age: 2...

journal_title：Physiological measurement

authors： Fukuda DH,Hetrick RP,Kendall KL,Smith-Ryan AE,Jackson ME,Stout JR

更新日期：2014-01-01 00:00:00

abstract：OBJECTIVE:Non-contact physiological measurement is a growing research area that allows capturing vital signs such as heart rate (HR) and breathing rate (BR) comfortably and unobtrusively with remote devices. However, most of the approaches work only in bright environments in which subtle photoplethysmographic and balli...

journal_title：Physiological measurement

authors： Chen W,Hernandez J,Picard RW

更新日期：2018-10-30 00:00:00

abstract：:Gastro-oesophageal pH measurements are routinely carried out to quantify and determine if levels of acid reflux are responsible for symptoms. Although considered the 'gold standard', evidence suggests that pH measurements do not correlate well with the degree of oesophagitis seen during endoscopy. In this study the cu...

journal_title：Physiological measurement

authors： Haylett KR,Vales P,Lee SH,McCloy RF

更新日期：2003-11-01 00:00:00

abstract：:Two studies concerning multi-frequency impedance measurements are presented. The first uses tetrapolar measurements made on the thorax and the second electrical impedance tomography images, also made from the thorax. The way in which the impedance and the changes in impedance with ventilation depend upon frequency are...

journal_title：Physiological measurement

authors： Brown BH,Barber DC,Wang W,Lu L,Leathard AD,Smallwood RH,Hampshire AR,Mackay R,Hatzigalanis K

更新日期：1994-05-01 00:00:00

abstract：OBJECTIVE:Metal exposures have been linked with many adverse health outcomes affecting nearly every system in the body. Exposure to metals has been tracked primarily using blood. Blood metal concentrations have drawbacks as biomarkers stemming from the metals' short biologic half-lives, shipping and storage requirement...

journal_title：Physiological measurement

authors： Specht AJ,Kponee K,Nkpaa KW,Balcom PH,Weuve J,Nie LH,Weisskopf MG

更新日期：2018-08-31 00:00:00

abstract：:Health is one of the most important non-material assets and thus also has an enormous influence on material values, since treating and preventing diseases is expensive. The number one cause of death worldwide today originates in cardiovascular diseases. For these reasons the aim of understanding the functions and the ...

journal_title：Physiological measurement

authors： Müller A,Kraemer JF,Penzel T,Bonnemeier H,Kurths J,Wessel N

更新日期：2016-05-01 00:00:00

abstract：:Electrical impedance tomography (EIT) is expected to become a valuable tool for monitoring mechanically ventilated patients due to its ability to continuously assess regional lung ventilation and aeration. Several sources of interference with EIT examinations exist in intensive care units (ICU). Our objectives are to ...

journal_title：Physiological measurement

authors： Frerichs I,Pulletz S,Elke G,Gawelczyk B,Frerichs A,Weiler N

更新日期：2011-12-01 00:00:00

abstract：OBJECTIVE:Transfer function analysis (TFA) of dynamic cerebral autoregulation (dCA) requires smoothing of spectral estimates using segmentation of the data (SD). Systematic studies are required to elucidate the potential influence of SD on dCA parameters. APPROACH:Healthy subjects (HS, n = 237) and acute ischaemic str...

journal_title：Physiological measurement

authors： Panerai RB,Intharakham K,Haunton V,Minhas JS,Llwyd O,Lam M,Salinet ASM,Nogueira RC,Katsogridakis E,Maggio P,Robinson TG

更新日期：2020-04-17 00:00:00

abstract：:The ability to predict if an atrial fibrillation (AF) episode terminates spontaneously or not through non-invasive techniques is a challenging problem of great clinical interest. This fact could avoid useless therapeutic interventions and minimize the risks for the patient. The present work introduces a robust AF pred...

journal_title：Physiological measurement

authors： Alcaraz R,Rieta JJ

更新日期：2008-01-01 00:00:00

abstract：BACKGROUND:Uterine activity monitoring is an essential part of managing the progress of pregnancy and labor. Although intrauterine pressure (IUP) is the only reliable method of estimating uterine mechanical activity, it is highly invasive. Since there is a direct relationship between the electrical and mechanical activ...

journal_title：Physiological measurement

authors： Benalcazar-Parra C,Garcia-Casado J,Ye-Lin Y,Alberola-Rubio J,Lopez Á,Perales-Marin A,Prats-Boluda G

更新日期：2019-09-03 00:00:00

abstract：:The recently-introduced technique of detrended fluctuation analysis (DFA) for heart-rate variability appears to yield improved prognostic power in cardiovascular disease through calculation of the fractal scaling exponent alpha. However, the physiological meaning of alpha remains unclear. In DFA, the signal is segment...

journal_title：Physiological measurement

authors： Willson K,Francis DP,Wensel R,Coats AJ,Parker KH

更新日期：2002-05-01 00:00:00

abstract：:Focused impedance measurements (FIM) are used in several fields, and address the problem of measuring the volume impedance of an object within a volume conductor. Several electrode configurations are possible, and these have different properties. Sensitivity fields of four configurations have been investigated. We pre...

journal_title：Physiological measurement

authors： Pettersen FJ,Ferdous H,Kalvøy H,Martinsen ØG,Høgetveit JO

更新日期：2014-06-01 00:00:00

abstract：:Plethysmographic measurement of airway resistance (R(aw)) has been determined by single-point analysis, usually at 50% of maximum inspiratory flow (MIF). Computer-assisted (best fit) analysis, however, allows R(aw) to be calculated by applying a regression line to any portion of the plethysmograph pressure-flow loop. ...

journal_title：Physiological measurement

authors： Thomas M,Greenough A,Blowes R,Rafferty GF,Calvert S,Marlow N,Peacock JL,Milner AD

更新日期：2002-05-01 00:00:00

abstract：:Several factors affect the viability of biosensor design. A computer-based model is being developed to enable the sources and effect of noise and variability within the sensor to be analysed. The work now presented details the modelling of the biochemical aspect of the biosensor model-the immunoassay. The equilibrium ...

journal_title：Physiological measurement

authors： Keating SM,Flanagan MT

更新日期：2001-08-01 00:00:00

abstract：:The changes in haemoglobin oxygenation (SO2) occurring in the tuberculin reaction in human skin were measured using macro- and micro-lightguide spectrophotometry and the results compared. A significant difference was found between the measurements from the respective instruments, demonstrating that the micro-lightguid...

journal_title：Physiological measurement

authors： Newton DJ,Harrison DK,Delaney CJ,Beck JS,McCollum PT

更新日期：1994-05-01 00:00:00