The effect of serial data collection on the accuracy of electrical impedance tomography images.

abstract：:In magnetic resonance electrical impedance tomography (MREIT) we inject currents through electrodes placed on the surface of a subject and try to reconstruct cross-sectional resistivity (or conductivity) images using internal magnetic flux density as well as boundary voltage measurements. In this paper we present a st...

journal_title：Physiological measurement

authors： Lee BI,Oh SH,Woo EJ,Lee SY,Cho MH,Kwon O,Seo JK,Baek WS

更新日期：2003-05-01 00:00:00

abstract：:The heart rate responds dynamically to various intrinsic and environmental stimuli. The autonomic nervous system is said to play a major role in this response. Multifractal analysis offers a novel method to assess the response of cardiac interbeat intervals. Twenty-four hour ECG recordings of RR interbeat intervals (o...

journal_title：Physiological measurement

authors： Makowiec D,Rynkiewicz A,Wdowczyk-Szulc J,Zarczyńska-Buchowiecka M,Gałaska R,Kryszewski S

更新日期：2011-10-01 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：:Twenty-nine patients were monitored overnight for breathing distress patterns during postoperative analgesia. Nasal flow apnoea monitoring and pulse oximetry data were recorded at 50 Hz. Respiratory inductive plethysmography (RIP) tracked tidal volume (TV) thoracoabdominal motion, and supplemented the flow monitoring ...

journal_title：Physiological measurement

authors： Millard RK

更新日期：1999-05-01 00:00:00

abstract：OBJECTIVE:Physical activity has been shown to impact future health outcomes in adults, but little is known about the long-term impact of physical activity in toddlers. Accurately measuring the specific types and amounts of physical activity in toddlers will help us to understand, predict, and better affect their future...

journal_title：Physiological measurement

authors： Albert MV,Sugianto A,Nickele K,Zavos P,Sindu P,Ali M,Kwon S

更新日期：2020-03-06 00:00:00

abstract：:Using the cross-sectional images taken with the zoom-in micro-tomography technique, we measured trabecular thicknesses of femur bones in postmortem rats. Since the zoom-in micro-tomography technique is capable of high resolution imaging of a small local region inside a large subject, we were able to measure the trabec...

journal_title：Physiological measurement

authors： Cho MH,Chun IK,Lee SC,Cho MH,Lee SY

更新日期：2005-10-01 00:00:00

abstract：:A magnetic pulse generator has been set up in order to study gastric activity. Two coils 1.05 m in diameter, arranged in a Helmholtz configuration, were used. The system generated magnetic field pulses higher than 15 mT, of duration 17.3+/-1.2 ms. Measurements were performed in 11 male volunteers, with average age 29....

journal_title：Physiological measurement

authors： Cordova-Fraga T,Bernal-Alvarado JJ,Gutierrez-Juarez G,Sosa M,Vargas-Luna M

更新日期：2004-10-01 00:00:00

abstract：OBJECTIVE:An artefact-free electrocardiogram (ECG) is essential during cardiac arrest to decide therapy such as defibrillation. Mechanical cardiopulmonary resuscitation (CPR) devices cause movement artefacts that alter the ECG. This study analyzes the effectiveness of mechanical CPR artefact suppression filters to rest...

journal_title：Physiological measurement

authors： Isasi I,Irusta U,Aramendi E,Idris AH,Sörnmo L

更新日期：2020-11-06 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：:Although cardiac arrhythmias have been studied extensively, little is known about arrhythmic phenomena in the gastrointestinal (GI) system. In this study, we demonstrate for the first time that the onset of GI arrhythmias is associated with statistically significant fluctuations in the information dimension of the ass...

journal_title：Physiological measurement

authors： Irimia A,Wikswo JP Jr

更新日期：2008-05-01 00:00:00

abstract：OBJECTIVE:This paper aims to report on the accuracy of estimating sleep stages using a wrist-worn device that measures movement using a 3D accelerometer and an optical pulse photoplethysmograph (PPG). APPROACH:Overnight recordings were obtained from 60 adult participants wearing these devices on their left and right w...

journal_title：Physiological measurement

authors： Beattie Z,Oyang Y,Statan A,Ghoreyshi A,Pantelopoulos A,Russell A,Heneghan C

更新日期：2017-10-31 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：:Electrical impedance is one of the most often used parameters for characterizing material properties, especially in biomedical applications. Electrical impedance spectroscopy (EIS), used for revealing both resistive and capacitive characteristics, is good for use in tissue characterization. In this study, a portable a...

journal_title：Physiological measurement

authors： Huang YJ,Huang EY,Lu YY,Chen CY,Cheng KS

更新日期：2011-09-01 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：:Urinary catheters (drainage tubes) are in widespread use. The most common type of long-term catheter is the Foley, which is made from natural or synthetic rubber. Foley catheters are passed into the bladder via the urethra or the suprapubic puncture channel (through the abdominal wall). A simulator for the abdominal w...

journal_title：Physiological measurement

authors： Coveney VA,Gröver D

更新日期：2001-08-01 00:00:00

abstract：:We present an adaptive algorithm for solving the inverse problem in electrical impedance tomography. To strike a balance between the accuracy of the reconstructed images and the computational efficiency of the forward and inverse solvers, we propose to combine an adaptive mesh refinement technique with the adaptive Ka...

journal_title：Physiological measurement

authors： Li T,Isaacson D,Newell JC,Saulnier GJ

更新日期：2014-06-01 00:00:00

abstract：OBJECTIVE:Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal disease characterized by excessive deposition of collagen and associated stiffening of lung tissue. While it is known that inflammation and dysfunction of fibroblasts are involved in disease development, it remains poorly understood how cells and ...

journal_title：Physiological measurement

authors： Wellman TJ,Mondoñedo JR,Davis GS,Bates JHT,Suki B

更新日期：2018-06-28 00:00:00

abstract：BACKGROUND AND OBJECTIVE:Walking is a complex human behavior, usually performed in a dynamic environment. Gait parameters are thought to reflect this complexity. Re-Step™ is a therapy system in the form of a computerized shoe, originally developed for the training and rehabilitation of individuals with brain damage. Th...

journal_title：Physiological measurement

authors： Koren Y,Raanan Y,Parmet Y,Bar-Haim S

更新日期：2018-04-26 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：:Energy scavenging has increasingly become an interesting option for powering electronic devices because of the almost infinite lifetime and the non-dependence on fuels for energy generation. Moreover, the rise of wireless technologies promises new applications in medical monitoring systems, but these still face limita...

journal_title：Physiological measurement

authors： Romero E,Warrington RO,Neuman MR

更新日期：2009-09-01 00:00:00

abstract：:The effects of mechanical stimulation on hemodynamics, such as due to mechanotransduction in vascular endothelial cells, have been widely discussed recently. We previously proposed a resonance model in which the arterial system is treated as a pressure-transmitting system, and suggested that the application of externa...

journal_title：Physiological measurement

authors： Hsiu H,Jan MY,Wang WK,Wang YY

更新日期：2006-02-01 00:00:00

abstract：:Wearables such as accelerometers are emerging as powerful tools for quantifying gait in various environments. Flexibility in wearable location may improve ease of use and data acquisition during instrumented testing. However, change of location may impact algorithm functionality when evaluating associated gait charact...

journal_title：Physiological measurement

authors： Del Din S,Hickey A,Hurwitz N,Mathers JC,Rochester L,Godfrey A

更新日期：2016-10-01 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：:Extension of the frequency range of electrical impedance myography (EIM) to 2 MHz discloses a major rise in the reactance of muscle above 3-500 kHz, together with a slow decrease in the resistance consonant with the Kramers-Kronig relations. This 'upturn' phenomenon is found when the distant current electrode configur...

journal_title：Physiological measurement

authors： Shiffman CA,Kashuri H,Aaron R

更新日期：2008-06-01 00:00:00

abstract：:A new method to image and quantify intra-abdominal haemorrhage using electrical impedance tomography (EIT) was tested in vivo. Supine peritoneal dialysis patients were monitored using an 8-electrode hemiarray placed on the anterior abdomen. EIT measurements were recorded using the EPack II data acquisition system befo...

journal_title：Physiological measurement

authors： Tucker AS,Ross EA,Paugh-Miller J,Sadleir RJ

更新日期：2011-02-01 00:00:00

abstract：:Easily applicable and inexpensive water-specific techniques to evaluate local oedema, swollen tissue problems and fluid retention in humans are not available. In the present investigation a recently constructed non-invasive device for a local measurement of changes in tissue water in human skin and subcutaneous fat (S...

journal_title：Physiological measurement

authors： Nuutinen J,Ikäheimo R,Lahtinen T

更新日期：2004-04-01 00:00:00

abstract：:The ability to image the impedance changes that accompany neuronal depolarization in the brain would constitute a major advance in neuroscience technology. Unfortunately, these changes are likely to be small and rapid and so difficult to measure. The impedance change at frequencies above 10 kHz, as used by conventiona...

journal_title：Physiological measurement

authors： Boone KG,Holder DS

更新日期：1995-08-01 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：:This review describes recent developments in microfabricated flow cytometers and related microfluidic devices that can detect, analyze, and sort cells or particles. The high-speed analytical capabilities of flow cytometry depend on the cooperative use of microfluidics, optics and electronics. Along with the improvemen...

journal_title：Physiological measurement

authors： Huh D,Gu W,Kamotani Y,Grotberg JB,Takayama S

更新日期：2005-06-01 00:00:00

abstract：:The purpose of this study was to examine the performance of dual-energy computed tomography (DECT) for the quantification of liver fat content (LFC). We prepared two phantoms: homogenized mixtures of porcine liver and fat and homogeneous mixtures of liver- and fat-equivalent solutions. Tubes containing mixtures with k...

journal_title：Physiological measurement

authors： Li JH,Tsai CY,Huang HM

更新日期：2014-04-01 00:00:00