Real time impedance plots with arbitrary frequency components.

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 which has nonstationary electrical characteristics. The system reported here obtains impedance spectra by applying a digitally constructed waveform consisting of many frequency components. This allows impedance values to be measured at a number of frequencies simultaneously. Sample data are provided and compared with data obtained using similar square wave techniques.

journal_name

Physiol Meas

authors

Searle A,Kirkup L

doi

10.1088/0967-3334/20/1/008

subject

Has Abstract

pub_date

1999-02-01 00:00:00

pages

103-14

issue

1

eissn

0967-3334

issn

1361-6579

journal_volume

20

pub_type

杂志文章
  • Imaging pathologic pulmonary air and fluid accumulation by functional and absolute EIT.

    abstract::The increasing use of EIT in clinical research on severely ill lung patients requires a clarification of the influence of pathologic impedance distributions on the validity of the resulting tomograms. Significant accumulation of low-conducting air (e.g. pneumothorax or emphysema) or well-conducting liquid (e.g. haemat...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/27/5/S16

    authors: Hahn G,Just A,Dudykevych T,Frerichs I,Hinz J,Quintel M,Hellige G

    更新日期:2006-05-01 00:00:00

  • In vivo neutron activation analysis of bone manganese in workers.

    abstract:OBJECTIVE:Manganese (Mn) is a neurotoxin. However, the impact of elevated, chronic Mn exposure is not well understood, partially due to the lack of a cumulative exposure biomarker. To address this gap, our group developed a compact in vivo neutron activation analysis (IVNAA) system to quantify Mn concentration in bone ...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/1361-6579/aaa749

    authors: Liu Y,Rolle-McFarland D,Mostafaei F,Zhou Y,Li Y,Zheng W,Wells E,Nie LH

    更新日期:2018-03-23 00:00:00

  • Techniques for early detection of Alzheimer's disease using spontaneous EEG recordings.

    abstract::Alzheimer's disease (AD) is a degenerative disease which causes serious cognitive decline. Studies suggest that effective treatments for AD may be aided by the detection of the disease in its early stages, prior to extensive neuronal degeneration. In this paper, we propose a set of novel techniques which could help to...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/28/4/001

    authors: Woon WL,Cichocki A,Vialatte F,Musha T

    更新日期:2007-04-01 00:00:00

  • Non-invasive, side-selective nasal airflow monitoring.

    abstract::Nasal obstruction disturbs comfort during daytime, and sleep quality. Convenient objective assessment of nasal ventilation would be desirable. Therefore, we developed a technique for unobtrusive monitoring of bilateral nasal airflow. Nasal cannulae with separated left- and right-sided tubings were connected to two pre...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/26/1/007

    authors: Kohler M,Thurnheer R,Bloch KE

    更新日期:2005-02-01 00:00:00

  • Value of simulated body surface potential maps as templates in localizing sites of ectopic activation for radiofrequency ablation.

    abstract::Body surface potential maps recorded during catheter pace mapping can facilitate the localization of the site of origin of ventricular tachycardia. In this study, we investigated the value of a realistic computer model of the human ventricular myocardium in generating body surface potential maps as templates for ident...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/18/4/010

    authors: Hren R,Horácek BM

    更新日期:1997-11-01 00:00:00

  • A medical thermal imaging device for the prevention of diabetic foot ulceration.

    abstract::In this paper a description is given of the development, characterisation and first results of a thermal imaging device aimed at significantly reducing the incidence of diabetic foot ulceration (DFU). These devices will be used in three clinical centres and in two preliminary clinical trials. The first will be on heal...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/1361-6579/aa56b1

    authors: Machin G,Whittam A,Ainarkar S,Allen J,Bevans J,Edmonds M,Kluwe B,Macdonald A,Petrova N,Plassmann P,Ring F,Rogers L,Simpson R

    更新日期:2017-03-01 00:00:00

  • The influence of cardiac preload and positive end-expiratory pressure on the pre-ejection period.

    abstract::The pre-ejection period (PEP) has recently been described as a potential parameter for monitoring cardiac preload. This study further investigated the influence of changes in intravascular volume status and the application of positive end-expiratory pressure (PEEP) on the pre-ejection period. In ten pigs, ECG, arteria...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/26/6/012

    authors: Kubitz JC,Kemming GI,Schultheib G,Starke J,Podtschaske A,Goetz AE,Reuter DA

    更新日期:2005-12-01 00:00:00

  • Effects of whole-body mechanical stimulation at double the heart rate on the blood pressure waveform in rats.

    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

    pub_type: 杂志文章

    doi:10.1088/0967-3334/27/2/004

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

    更新日期:2006-02-01 00:00:00

  • A randomized controlled trial studying the effect of maternal hyperoxygenation on fetal heart rate in suspected fetal distress.

    abstract:OBJECTIVE:To investigate the effect of maternal hyperoxygenation on fetal heart rate (FHR) when applied for suspected fetal distress during the second stage of term labor. APPROACH:A single-center randomized controlled trial was conducted in a tertiary care hospital in The Netherlands. Participants were included durin...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/1361-6579/abc0b6

    authors: Moors S,Joshi R,Bullens LM,van Oostrum NHM,Regis M,van den Heuvel ER,Oei SG,van Laar JOEH,van der Hout-van der Jagt MB

    更新日期:2020-12-11 00:00:00

  • Recognition of elementary arm movements using orientation of a tri-axial accelerometer located near the wrist.

    abstract::In this paper we present a method for recognising three fundamental movements of the human arm (reach and retrieve, lift cup to mouth, rotation of the arm) by determining the orientation of a tri-axial accelerometer located near the wrist. Our objective is to detect the occurrence of such movements performed with the ...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/35/9/1751

    authors: Biswas D,Corda D,Baldus G,Cranny A,Maharatna K,Achner J,Klemke J,Jöbges M,Ortmann S

    更新日期:2014-09-01 00:00:00

  • Localization of sources of brain alpha/theta/delta activity and the influence of the mode of spontaneous mentation.

    abstract::A method is described that accounts for multichannel brain field data (EEG) epochs, after transformation into the frequency domain, by a single oscillating dipole source in terms of phase angles. The method produces a potential distribution for each frequency point ('FFT dipole approximation'). These maps can be subje...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/14/4a/004

    authors: Michel CM,Henggeler B,Brandeis D,Lehmann D

    更新日期:1993-11-01 00:00:00

  • Time-varying analysis of heart rate variability signals with a Kalman smoother algorithm.

    abstract::A time-varying parametric spectrum estimation method for analysing non-stationary heart rate variability signals is presented. As a case study, the dynamics of heart rate variability during an orthostatic test is examined. In this method, the non-stationary signal is first modelled with a time-varying autoregressive m...

    journal_title:Physiological measurement

    pub_type: 临床试验,杂志文章

    doi:10.1088/0967-3334/27/3/002

    authors: Tarvainen MP,Georgiadis SD,Ranta-Aho PO,Karjalainen PA

    更新日期:2006-03-01 00:00:00

  • Use of the discriminant Fourier-derived cepstrum with feature-level post-processing for surface electromyographic signal classification.

    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

    pub_type: 杂志文章

    doi:10.1088/0967-3334/30/12/008

    authors: Chen X,Zhu X,Zhang D

    更新日期:2009-12-01 00:00:00

  • Personalized automatic sleep staging with single-night data: a pilot study with Kullback-Leibler divergence regularization.

    abstract:OBJECTIVE:Brain waves vary between people. This work aims to improve automatic sleep staging for longitudinal sleep monitoring via personalization of algorithms based on individual characteristics extracted from sleep data recorded during the first night. APPROACH:As data from a single night are very small, thereby ma...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/1361-6579/ab921e

    authors: Phan H,Mikkelsen K,Chén OY,Koch P,Mertins A,Kidmose P,De Vos M

    更新日期:2020-07-01 00:00:00

  • Patient examinations using electrical impedance tomography--sources of interference in the intensive care unit.

    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

    pub_type: 杂志文章

    doi:10.1088/0967-3334/32/12/F01

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

    更新日期:2011-12-01 00:00:00

  • The effect of ambient air temperature on whole-body bioelectrical impedance.

    abstract::It has previously been shown that extreme changes in ambient air temperature can affect whole-body bioelectrical impedance. The purpose of this study was to determine if more moderate changes in ambient air temperature, such as those experienced in most laboratory settings, would also affect bioelectric impedance anal...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/25/1/011

    authors: Buono MJ,Burke S,Endemann S,Graham H,Gressard C,Griswold L,Michalewicz B

    更新日期:2004-02-01 00:00:00

  • Validation of x-ray fluorescence measurements of metals in toenail clippings against inductively coupled plasma mass spectrometry in a Nigerian population.

    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

    pub_type: 杂志文章

    doi:10.1088/1361-6579/aad947

    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

  • Characterization of cardiorespiratory phase synchronization and directionality in late premature and full term infants.

    abstract:OBJECTIVE:Though the mutual influence of cardiovascular and respiratory rhythms in healthy newborns has been documented, its full characterization is still pending. In general, the activity of many physiological subsystems has a well-expressed rhythmic character, and often an interdependency between physiological rhyth...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/1361-6579/aac553

    authors: Lucchini M,Pini N,Fifer WP,Burtchen N,Signorini MG

    更新日期:2018-06-19 00:00:00

  • Preliminary static EIT images of the thorax in health and disease.

    abstract::The results of a preliminary clinical evaluation of a one-frequency electrical impedance tomography (EIT) system enabling static in vivo imaging are presented. The design of the measuring system and image reconstruction software are described. Thirty-one subjects were examined and divided into four clinical groups. Th...

    journal_title:Physiological measurement

    pub_type: 临床试验,杂志文章

    doi:10.1088/0967-3334/23/1/304

    authors: Cherepenin V,Karpov A,Korjenevsky A,Kornienko V,Kultiasov Y,Mazaletskaya A,Mazourov D

    更新日期:2002-02-01 00:00:00

  • Variability in estimating shunt from single pulse oximetry measurements.

    abstract::Virtual shunt describes the overall loss of O2 content between the alveolar gas and arterial blood. Clinicians indirectly estimate the magnitude of the virtual shunt by monitoring peripheral blood oxygen saturation (SpO2) using non-invasive pulse oximetry. An inherent limitation of this method is the variable precisio...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/36/5/967

    authors: Karlen W,Petersen CL,Dumont GA,Ansermino JM

    更新日期:2015-05-01 00:00:00

  • A multi-frequency EIT system design based on telecommunication signal processors.

    abstract::A multi-frequency electrical impedance tomography system for cardiopulmonary monitoring has been designed with specialized digital signal processors developed primarily for the telecommunications sector. The system consists of two modules: a scan-head and a base-station. The scan-head, located close to the patient's t...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/30/6/S04

    authors: Robitaille N,Guardo R,Maurice I,Hartinger AE,Gagnon H

    更新日期:2009-06-01 00:00:00

  • A measurement of pulmonary blood volume increase during systole in humans.

    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

    pub_type: 临床试验,杂志文章

    doi:10.1088/0967-3334/15/4/010

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

    更新日期:1994-11-01 00:00:00

  • A shape-based quality evaluation and reconstruction method for electrical impedance tomography.

    abstract::Linear methods of reconstruction play an important role in medical electrical impedance tomography (EIT) and there is a wide variety of algorithms based on several assumptions. With the Graz consensus reconstruction algorithm for EIT (GREIT), a novel linear reconstruction algorithm as well as a standardized framework ...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/36/6/1161

    authors: Antink CH,Pikkemaat R,Malmivuo J,Leonhardt S

    更新日期:2015-06-01 00:00:00

  • A planar elliptical model of cardio-vagal hysteresis.

    abstract::The state-dependent portion of cardio-vagal baroreflex control is called baroreflex hyteresis: we observe hysteresis when RR interval and carotid diameter depend on both the direction and value of arterial pressure. The elasticity of arterial walls, as well as the responsiveness of central command reset controls the r...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/31/6/009

    authors: Ler AS,Cohen MA,Taylor JA

    更新日期:2010-06-01 00:00:00

  • Recording of ENGs from the nerves innervating the pancreas of a dog during the intravenous glucose tolerance test.

    abstract::Electroneurograms (ENGs) from the vagus nerve (VN), the splanchnic nerve (SN) and the pancreatic nerve (PN) innervating the pancreas of a dog, were recorded with chronically implanted 33-electrode spiral cuffs (cuff) before and after the pancreas were stimulated with intravenously (i.v.) administered glucose. In the c...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/23/4/309

    authors: Rozman J,Zorko B,Bunc M,Mikac U,Tegou E

    更新日期:2002-11-01 00:00:00

  • Assessment of cerebrospinal fluid outflow conductance using an adaptive observer--experimental and clinical evaluation.

    abstract::Idiopathic normal pressure hydrocephalus (INPH) patients have a disturbance in the dynamics of the cerebrospinal fluid (CSF) system. The outflow conductance, C, of the CSF system has been suggested to be prognostic for positive outcome after treatment with a CSF shunt. All current methods for estimation of C have draw...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/28/11/003

    authors: Andersson K,Manchester IR,Andersson N,Shiriaev A,Malm J,Eklund A

    更新日期:2007-11-01 00:00:00

  • Adipose tissue thickness does not affect the electromechanical delay.

    abstract::During voluntary contractions in humans, the subcutaneous tissues between surface electrodes and active motor units have been shown to attenuate surface electromyographic (EMG) signal amplitude. The purpose of this investigation was to examine the relationship between adipose tissue thickness and the electromechnical ...

    journal_title:Physiological measurement

    pub_type: 临床试验,杂志文章

    doi:10.1088/0967-3334/37/3/418

    authors: Stock MS,Thompson BJ

    更新日期:2016-03-01 00:00:00

  • PaCO2 measurement in cerebral haemodynamics: face mask or nasal cannulae?

    abstract:OBJECTIVE:PaCO2 affects cerebral blood flow (CBF) and its regulatory mechanisms, but the effects of CO2 measurement technique on cerebrovascular parameters are unknown. In order to determine if the two most commonly used approaches, face mask (FM) or nasal cannulae (NC), are interchangeable or not, we tested the hypoth...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/1361-6579/aa6f9f

    authors: Minhas JS,Robinson T,Panerai R

    更新日期:2017-06-22 00:00:00

  • In vitro measurements of respiratory mechanics during HFPV using a mechanical lung model.

    abstract::High-frequency percussive ventilation (HFPV) may be defined as flow-regulated time-cycled ventilation that creates controlled pressure and delivers a series of high-frequency subtidal volumes in combination with low-frequency breathing cycles. In recent years, the usefulness of HFPV has been clinically assessed as an ...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/32/6/002

    authors: Riscica F,Lucangelo U,Ferluga M,Accardo A

    更新日期:2011-06-01 00:00:00

  • Determination of Cole parameters in multiple frequency bioelectrical impedance analysis using only the measurement of impedances.

    abstract::Conventional bioimpedance spectrometers measure resistance and reactance over a range of frequencies and, by application of a mathematical model for an equivalent circuit (the Cole model), estimate resistance at zero and infinite frequencies. Fitting of the experimental data to the model is accomplished by iterative, ...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/27/9/007

    authors: Ward LC,Essex T,Cornish BH

    更新日期:2006-09-01 00:00:00