Circuit modeling of the electrical impedance: II. Normal subjects and system reproducibility.

abstract：:Pulmonary blood volume increase during systole was measured in patients by analysing chest images obtained during ECG gated radionuclide angiography examination. The difference in the total radiation counts between systole and diastole in regions of interest, which included the lungs and the left ventricle, was measur...

journal_title：Physiological measurement

authors： Nitzan M,Mahler Y,Schechter D,Yaffe S,Bocher M,Chisin R

更新日期：1994-11-01 00:00:00

abstract：:Gated SPECT (GSPECT) was evaluated for the measurement of left ventricular ejection fraction (LVEF) by comparing with equilibrium gated radionuclide ventriculography (RNVG). A total of 99 subjects underwent GSPECT and RNVG imaging. All studies were acquired in list mode with GSPECT studies processed to give 16- and 8-...

journal_title：Physiological measurement

authors： Wright GA,McDade M,Keeble W,Martin W,Hutton I

更新日期：2001-05-01 00:00:00

abstract：OBJECTIVE:Accurate bladder size estimation is an important clinical parameter that assists physicians, enabling them to provide better treatment for patients who are suffering from urinary incontinence. Electrical impedance tomography (EIT) is a non-invasive medical imaging method that estimates organ boundaries assumi...

journal_title：Physiological measurement

authors： Konki SK,Khambampati AK,Sharma SK,Kim KY

更新日期：2020-12-18 00:00:00

abstract：:Cerebral autoregulation has been studied by linear filter systems, with arterial blood pressure (ABP) as the input and cerebral blood flow velocity (CBFV-from transcranial Doppler Ultrasound) as the output. The current work extends this by using adaptive filters to investigate the dynamics of time-varying cerebral aut...

journal_title：Physiological measurement

authors： Liu J,Simpson MD,Yan J,Allen R

更新日期：2010-10-01 00:00:00

abstract：:Peripheral vasculature disease is strongly correlated with cardiovascular-associated mortality. Monitoring circulation health, especially in the peripheral limbs, is vital to detecting clinically significant disease at a stage when it can still be addressed through medical intervention. Electrical impedance tomography...

journal_title：Physiological measurement

authors： Halter R,Hartov A,Paulsen K

更新日期：2008-03-01 00:00:00

abstract：OBJECTIVE:Bioimpedance has been used to investigate changes in electrical parameters during ischemia in various tissues. The small intestine is a multi-layered structure, with several distinct tissue types, and ischemia related changes occur at different times in the different intestinal layers. When investigating how ...

journal_title：Physiological measurement

authors： Strand-Amundsen RJ,Reims HM,Tronstad C,Kalvøy H,Martinsen ØG,Høgetveit JO,Ruud TE,Tønnessen TI

更新日期：2017-05-01 00:00:00

abstract：:Reliability of cerebral blood flow velocity (CBFV) and dynamic cerebral autoregulation estimates (expressed as autoregulation index: ARI) using spontaneous fluctuations in blood pressure (BP) has been demonstrated. However, reliability during co-administration of O2 and CO2 is unknown. Bilateral CBFV (using transcrani...

journal_title：Physiological measurement

authors： Minhas JS,Syed NF,Haunton VJ,Panerai RB,Robinson TG,Mistri AK

更新日期：2016-05-01 00:00:00

abstract：:Electrical impedance tomography (EIT) measures the conductivity distribution within an object based on the current applied and voltage measured at surface electrodes. Thus, EIT images are sensitive to electrode properties (i.e. contact impedance, electrode area and boundary shape under the electrode). While some of th...

journal_title：Physiological measurement

authors： Boyle A,Adler A

更新日期：2011-07-01 00:00:00

abstract：:The literature concerning measurement of spatial resolution in electrical impedance tomography (EIT) is vague. Different groups often use their own method or a modified version of a better known method, thus hindering a generalized resolution measurement which could be useful for gauging the performance of one system ...

journal_title：Physiological measurement

authors： Wheeler JL,Wang W,Tang M

更新日期：2002-02-01 00:00:00

abstract：:Previous studies have used isokinetic dynamometry to assess joint torques and angles during passive extension of the knee, often without reporting upon methodological errors and reliability outcomes. In addition, the reliability of the techniques used to measure passive knee extension torque-angle and the extent to wh...

journal_title：Physiological measurement

authors： Freitas SR,Vaz JR,Bruno PM,Valamatos MJ,Mil-Homens P

更新日期：2013-11-01 00:00:00

abstract：:Acupuncture (ACU) is known to be effective in ischemia treatment, and glutamate (GLU) excitotoxicity is an important factor in neuronal cell death. We observed the effect of ACU on cerebral blood flow (%CBF) and DeltaGLU (the changes in GLU release) in the ischemic stroke rat model of diabetic mellitus (DM). A global ...

journal_title：Physiological measurement

authors： Choi S,Lee GJ,Chae SJ,Kang SW,Yin CS,Lee SH,Choi SK,Park HK

更新日期：2010-05-01 00:00:00

abstract：:Electrical impedance tomography (EIT) is very sensitive to deformations of the medium boundary shape. For lung imaging, breathing and changes in posture move the electrodes and change the chest shape, resulting in image artefacts. Several approaches have been proposed to improve the reconstructed images; most methods ...

journal_title：Physiological measurement

authors： Gómez-Laberge C,Adler A

更新日期：2008-06-01 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：:If electrical impedance tomography is to be used as a clinical tool, the image reconstruction algorithms must yield accurate images of impedance changes. One of the keys to producing an accurate reconstructed image is the inclusion of prior information regarding the physical geometry of the object. To achieve this, ma...

journal_title：Physiological measurement

authors： Bayford RH,Gibson A,Tizzard A,Tidswell T,Holder DS

更新日期：2001-02-01 00:00:00

abstract：:The assessment and diagnosis of lower limb peripheral arterial occlusive disease (PAOD) is important since it can lead progressively to disabling claudication, ischaemic rest pain and gangrene. Historically, the first assessment has been palpation of the peripheral pulse since it can become damped, delayed and diminis...

journal_title：Physiological measurement

authors： Allen J,Oates CP,Lees TA,Murray A

更新日期：2005-10-01 00:00:00

abstract：:Electrocardiograms (ECGs) recorded from patients in intensive care were investigated to quantify any relationship between ECG signal quality and false monitoring alarms. False alarms are a considerable problem for nursing and medical staff as they distract from clinical care, and are also a problem for patients as the...

journal_title：Physiological measurement

authors： Tsimenidis C,Murray A

更新日期：2016-08-01 00:00:00

abstract：:Myoelectrical pattern classification is a crucial part in multi-functional prosthesis control. This paper investigates a discriminant Fourier-derived cepstrum (DFC) and feature-level post-processing (FLPP) to discriminate hand and wrist motions using the surface electromyographic signal. The Fourier-derived cepstrum t...

journal_title：Physiological measurement

authors： Chen X,Zhu X,Zhang D

更新日期：2009-12-01 00:00:00

abstract：:The holy grail of neuroimaging would be to have an imaging system, which could image neuronal electrical activity over milliseconds. One way to do this would be by imaging the impedance changes associated with ion channels opening in neuronal membranes in the brain during activity. In principle, we could measure this ...

journal_title：Physiological measurement

authors： Ahadzi GM,Liston AD,Bayford RH,Holder DS

更新日期：2004-02-01 00:00:00

abstract：:There is considerable interest in unobtrusive and portable methods of monitoring sleepiness outside the laboratory setting. This study evaluates the usefulness of combined electrocardiogram (ECG) and photoplethysmogram (PPG) measurements for estimating psychomotor vigilance. The psychomotor vigilance test (PVT) was pe...

journal_title：Physiological measurement

authors： Chua CP,McDarby G,Heneghan C

更新日期：2008-08-01 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：:Although previous studies have established the feasibility of monitoring esophageal temperature during radiofrequency cardiac ablation using an esophageal temperature probe (ETP), some questions remain regarding its efficacy. The aims of this study were to study the effect of the location of the ETP on the temperature...

journal_title：Physiological measurement

authors： Rodríguez I,Lequerica JL,Berjano EJ,Herrero M,Hornero F

更新日期：2007-05-01 00:00:00

abstract：:Temporal changes in the impedance spectra of bioelectrodes in contact with skin provide useful data for comparisons between differing electrode materials and skin preparation methods. Traditional impedance measuring systems employ swept frequency methods which will distort results in the impedance spectra of a sample ...

journal_title：Physiological measurement

authors： Searle A,Kirkup L

更新日期：1999-02-01 00:00:00

abstract：:Muscle stiffness is known to vary as a result of a variety of disease states, yet current clinical methods for quantifying muscle stiffness have limitations including cost and availability. We investigated the capability of shear wave elastography (SWE) to measure variations in gastrocnemius shear wave speed induced v...

journal_title：Physiological measurement

authors： Chernak LA,DeWall RJ,Lee KS,Thelen DG

更新日期：2013-06-01 00:00:00

abstract：:In this paper we present the T-SCAN technology and its use as a diagnostic tool for breast cancer detection. We show, using theoretical models with simplified geometries, that displaying planar two-dimensional maps of the currents detected at the breast's surface relate to the electric field distribution within the br...

journal_title：Physiological measurement

authors： Assenheimer M,Laver-Moskovitz O,Malonek D,Manor D,Nahaliel U,Nitzan R,Saad A

更新日期：2001-02-01 00:00:00

abstract：:Electrical impedance spectroscopy has been developed as a potential method for the diagnosis of carcinoma in epithelial tissues. An understanding of the influence of structural changes in the tissue on the properties measured using this technique is essential for interpreting measured data and optimization of probe de...

journal_title：Physiological measurement

authors： Walker DC,Smallwood RH,Keshtar A,Wilkinson BA,Hamdy FC,Lee JA

更新日期：2005-06-01 00:00:00

abstract：:A photoacoustic technique is used for studying topically applied substance absorption in human skin. The proposed method utilizes a double-chamber PA cell. The absorption determination was obtained through the measurement of the thermal effusivity of the binary system substance-skin. The theoretical model assumes that...

journal_title：Physiological measurement

authors： Gutiérrez-Juárez G,Vargas-Luna M,Córdova T,Varela JB,Bernal-Alvarado JJ,Sosa M

更新日期：2002-08-01 00:00:00

abstract：:Previous studies demonstrate that it is possible to evaluate a heart graft rejection condition using a bioimpedance technique by means of an intracavitary catheter. We propose to use a less invasive technique consisting in the use of a transoesophageal catheter and two standard ECG electrodes on the thorax. The aim of...

journal_title：Physiological measurement

authors： Giovinazzo G,Ribas N,Cinca J,Rosell-Ferrer J

更新日期：2011-07-01 00:00:00

abstract：:The activPAL™ activity monitor has potential for use in youth with Cerebral Palsy (CP) as it has demonstrated acceptable validity for the assessment of sedentary and physical activity in other populations. This study determined the validity of the activPAL™ activity monitor for the measurement of sitting, standing, wa...

journal_title：Physiological measurement

authors： O' Donoghue D,Kennedy N

更新日期：2014-11-01 00:00:00

abstract：:The electrocardiogram (ECG) is a well studied signal from which many clinically relevant parameters can be derived, such as heart rate. A key component in the estimation of these parameters is the accurate detection of the R peak in the QRS complex. While corruption of the ECG by movement artefact or sensor failure ca...

journal_title：Physiological measurement

authors： Johnson AE,Behar J,Andreotti F,Clifford GD,Oster J

更新日期：2015-08-01 00:00:00

abstract：:ECG-gated electrical impedance tomographic spectroscopy (EITS) measurements of the lungs were taken on seven normal subjects in the frequency range 9.6 kHz to 614.4 kHz. The results show that in late systole the resistivity p' relative to the R-wave (i.e. p' = 1 at the R-wave) decreases consistently within the lung. I...

journal_title：Physiological measurement

authors： Nopp P,Zhao TX,Brown BH,Wang W

更新日期：1996-11-01 00:00:00