Characteristic impedance: frequency or time domain approach?

Abstract:

OBJECTIVE:Characteristic impedance (Zc) is an important component in the theory of hemodynamics. It is a commonly used metric of proximal arterial stiffness and pulse wave velocity. Calculated using simultaneously measured dynamic pressure and flow data, estimates of characteristic impedance can be obtained using methods based on frequency or time domain analysis. Applications of these methods under different physiological and pathological conditions in species with different body sizes and heart rates show that the two approaches do not always agree. In this study, we have investigated the discrepancies between frequency and time domain estimates accounting for uncertainties associated with experimental processes and physiological conditions. APPROACH:We have used published data measured in different species including humans, dogs, and mice to investigate: (a) the effects of time delay and signal noise in the pressure-flow data, (b) uncertainties about the blood flow conditions, (c) periodicity of the cardiac cycle versus the breathing cycle, on the frequency and time domain estimates of Zc, and (d) if discrepancies observed under different hemodynamic conditions can be eliminated. Main results and Significance: We have shown that the frequency and time domain estimates are not equally sensitive to certain characteristics of hemodynamic signals including phase lag between pressure and flow, signal to noise ratio and the end of systole retrograde flow. The discrepancies between two types of estimates are inherent due to their intrinsically different mathematical expressions and therefore it is impossible to define a criterion to resolve such discrepancies. Considering the interpretation and role of Zc as an important hemodynamic parameter, we suggest that the frequency and time domain estimates should be further assessed as two different hemodynamic parameters in a future study.

journal_name

Physiol Meas

authors

Qureshi MU,Colebank MJ,Schreier DA,Tabima DM,Haider MA,Chesler NC,Olufsen MS

doi

10.1088/1361-6579/aa9d60

subject

Has Abstract

pub_date

2018-01-31 00:00:00

pages

014004

issue

1

eissn

0967-3334

issn

1361-6579

journal_volume

39

pub_type

杂志文章
  • A clinical distortion index for compressed echocardiogram evaluation: recommendations for Xvid codec.

    abstract::This paper introduces a new clinical distortion index able to measure the decrease in diagnostic content in compressed echocardiograms. It is calculated using cardiologists' answers to a clinical testbed composed of two types of tests: one blind and the other semi-blind. This index may be used to compare clinical perf...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/30/5/001

    authors: Alesanco A,Hernández C,Portolés A,Ramos L,Aured C,García M,Serrano P,García J

    更新日期:2009-05-01 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 independent components of auditory P300 and CNV evoked potentials derived from single-trial recordings.

    abstract::The back-projected independent components (BICs) of single-trial, auditory P300 and contingent negative variation (CNV) evoked potentials (EPs) were derived using independent component analysis (ICA) and cluster analysis. The method was tested in simulation including a study of the electric dipole equivalents of the s...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/28/8/001

    authors: Jervis B,Belal S,Camilleri K,Cassar T,Bigan C,Linden DE,Michalopoulos K,Zervakis M,Besleaga M,Fabri S,Muscat J

    更新日期:2007-08-01 00:00:00

  • The physiological impact of the nonlinearity of arterial elasticity in the ambulatory arterial stiffness index.

    abstract::The ambulatory arterial stiffness index (AASI) is claimed to be a new estimator for arterial rigidity. It was recently defined as one minus the slope of the linear regression of systolic to diastolic ambulatory pressure during 24 h. Although several reports testify its clinical relevance, the explanation of how this n...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/31/7/012

    authors: Craiem D,Graf S,Salvucci F,Chironi G,Megnien JL,Simon A,Armentano RL

    更新日期:2010-07-01 00:00:00

  • Modelling of the immunoassay element of an optical immunosensor.

    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

    pub_type: 杂志文章

    doi:10.1088/0967-3334/22/3/318

    authors: Keating SM,Flanagan MT

    更新日期:2001-08-01 00:00:00

  • A novel method for continuous blood pressure estimation based on a single-channel photoplethysmogram signal.

    abstract:OBJECTIVE:Currently, continuous blood pressure (BP) measurements are mostly based on multi-sensor combinations and datasets with limited BP ranges. Besides, most BP-related features derive from the photoplethysmogram (PPG) signal. The mechanism of PPG signal formation is not considered. We aimed to design a noninvasive...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/1361-6579/abc8dd

    authors: Hu Q,Deng X,Wang A,Yang C

    更新日期:2021-01-01 00:00:00

  • The impact of electrode area, contact impedance and boundary shape on EIT images.

    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

    pub_type: 杂志文章

    doi:10.1088/0967-3334/32/7/S02

    authors: Boyle A,Adler A

    更新日期:2011-07-01 00:00:00

  • Real-time arrhythmia detection with supplementary ECG quality and pulse wave monitoring for the reduction of false alarms in ICUs.

    abstract::False intensive care unit (ICU) alarms induce stress in both patients and clinical staff and decrease the quality of care, thus significantly increasing both the hospital recovery time and rehospitalization rates. In the PhysioNet/CinC Challenge 2015 for reducing false arrhythmia alarms in ICU bedside monitor data, th...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/37/8/1273

    authors: Krasteva V,Jekova I,Leber R,Schmid R,Abächerli R

    更新日期:2016-08-01 00:00:00

  • Compressive sensing in electrical impedance tomography for breathing monitoring.

    abstract:OBJECTIVE:Electrical impedance tomography (EIT) is a functional imaging technique in which cross-sectional images of structures are reconstructed based on boundary trans-impedance measurements. Continuous functional thorax monitoring using EIT has been extensively researched. Increasing the number of electrodes, number...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/1361-6579/ab0daa

    authors: Shiraz A,Khodadad D,Nordebo S,Yerworth R,Frerichs I,van Kaam A,Kallio M,Papadouri T,Bayford R,Demosthenous A

    更新日期:2019-04-03 00:00:00

  • Decomposition method of an electrical bio-impedance signal into cardiac and respiratory components.

    abstract::The paper presents a method for adaptive decomposition of an electrical bio-impedance (BI) signal into two components: cardiac and respiratory. The decomposition of a BI signal is not a trivial process because of the non-stationarity of the signal components and overlapping of their harmonic spectra. An application sp...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/29/6/S02

    authors: Krivoshei A,Kukk V,Min M

    更新日期:2008-06-01 00:00:00

  • In vivo measurement of human skin absorption of topically applied substances by a photoacoustic technique.

    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

    pub_type: 杂志文章

    doi:10.1088/0967-3334/23/3/304

    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

  • Solving the forward problem in electrical impedance tomography for the human head using IDEAS (integrated design engineering analysis software), a finite element modelling tool.

    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

    pub_type: 杂志文章

    doi:10.1088/0967-3334/22/1/308

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

    更新日期:2001-02-01 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

  • Identification of oxygen-19 during in vivo neutron activation analysis of water phantoms.

    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

    pub_type: 杂志文章

    doi:10.1088/0967-3334/36/12/N127

    authors: Tahir SN,Chettle DR

    更新日期:2015-12-01 00:00:00

  • Non-contact video-based vital sign monitoring using ambient light and auto-regressive models.

    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

    pub_type: 杂志文章

    doi:10.1088/0967-3334/35/5/807

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

    更新日期:2014-05-01 00:00:00

  • 3D reconstruction in electrical impedance imaging using a direct sensitivity matrix approach.

    abstract::This paper represents a reconstruction algorithm using a direct sensitivity matrix (DSM) approach for fast 3D image reconstruction in electrical impedance imaging. The boundary element method (BEM) is used in the construction of this matrix. The first images of a conductivity perturbation inside a sphere are reconstru...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/16/3a/012

    authors: Morucci JP,Granié M,Lei M,Chabert M,Marsili PM

    更新日期:1995-08-01 00:00:00

  • Sensitivity matrix and reconstruction algorithm for EIT assuming axial uniformity.

    abstract::In electrical impedance tomography (EIT) two-dimensional models continue to be applied despite their known inability to provide correct reconstruction. In this paper, a reconstruction algorithm that assumes a translationally invariant conductivity distribution is described. A more precise forward solver is obtained by...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/21/1/308

    authors: Jerbi K,Lionheart WR,Vauhkonen PJ,Vauhkonen M

    更新日期:2000-02-01 00:00:00

  • A multifrequency multichannel electrical impedance data acquisition system for body fluid shift monitoring.

    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

    pub_type: 杂志文章

    doi:10.1088/0967-3334/16/4/003

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

    更新日期:1995-11-01 00:00:00

  • Thermography and colour duplex ultrasound assessments of arterio-venous fistula function in renal patients.

    abstract::Vascular and clinical assessments of arterio-venous fistula (AVF) function and access are important in patients undergoing or preparing to undergo renal dialysis. Objective assessment techniques include colour duplex ultrasound and more recently medical infrared thermography. Ideally, these should help assess problems...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/27/1/005

    authors: Allen J,Oates CP,Chishti AD,Ahmed IA,Talbot D,Murray A

    更新日期:2006-01-01 00:00:00

  • Wearable oxygen uptake and energy expenditure monitors.

    abstract::Obesity is a major health issue in both developed and developing countries. The balance between energy intake and exercise is important, and measurements of both energy intake and energy expenditure are required. Many studies have attempted to monitor energy intake via wearable technology, but no standard methods have...

    journal_title:Physiological measurement

    pub_type: 杂志文章,评审

    doi:10.1088/1361-6579/ab3827

    authors: Tamura T

    更新日期:2019-09-03 00:00:00

  • Physiological motion monitoring: a wearable device and adaptative algorithm for sit-to-stand timing detection.

    abstract::A simple wearable device for sit-to-stand timing detection was designed and constructed with rate gyroscopes and accelerometers and a dedicated adaptive algorithm. The method was validated by comparison with optoelectronic equipment. Results from the comparison showed a maximal error always lower than 2.5 x 10(-2) s f...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/27/8/006

    authors: Giansanti D,Maccioni G

    更新日期:2006-08-01 00:00:00

  • An efficient unsupervised fetal QRS complex detection from abdominal maternal ECG.

    abstract::Non-invasive fetal heart rate is of great relevance in clinical practice to monitor fetal health state during pregnancy. To date, however, despite significant advances in the field of electrocardiography, the analysis of abdominal fetal ECG is considered a challenging problem for biomedical and signal processing commu...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/35/8/1607

    authors: Varanini M,Tartarisco G,Billeci L,Macerata A,Pioggia G,Balocchi R

    更新日期:2014-08-01 00:00:00

  • Chasing the evidence: the influence of data segmentation on estimates of dynamic cerebral autoregulation.

    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

    pub_type: 杂志文章

    doi:10.1088/1361-6579/ab7ddf

    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

  • An optimized lead system for long-term esophageal electrocardiography.

    abstract::Long-term electrocardiography (ECG) featuring adequate atrial and ventricular signal quality is highly desirable. Routinely used surface leads are limited in atrial signal sensitivity and recording capability impeding complete ECG delineation, i.e. in the presence of supraventricular arrhythmias. Long-term esophageal ...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/35/4/517

    authors: Niederhauser T,Haeberlin A,Marisa T,Mattle D,Abächerli R,Goette J,Jacomet M,Vogel R

    更新日期:2014-04-01 00:00:00

  • Coordinated FA-MS and SIFT-MS analyses of breath following ingestion of D2O and ethanol: total body water, dispersal kinetics and ethanol metabolism.

    abstract::A coordinated study of the dispersal of water between the various body compartments (stomach and gut, blood stream and tissue) and the similar dispersal kinetics of ethanol and its metabolism has been carried out involving two healthy volunteers using flowing afterglow mass spectrometry, FA-MS, and selected ion flow t...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/26/4/011

    authors: Spanel P,Wang T,Smith D

    更新日期:2005-08-01 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

  • New porcine test-model reveals remarkable differences between algorithms for spectrophotometrical haemoglobin saturation measurements with VLS.

    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

    pub_type: 杂志文章

    doi:10.1088/0967-3334/37/9/1624

    authors: Gade J,Greisen G

    更新日期:2016-09-01 00:00:00

  • Test-retest reliability and minimal detectable change of repeated sit-to-stand analysis using one body fixed sensor in geriatric patients.

    abstract::A majority of geriatric patients experience difficulty in performing sit-to-stand (SiSt) transitions. A detailed assessment of SiSt ability is a prerequisite for successful rehabilitation. Body fixed sensors (BFSs) are increasingly used to assess functional performances. As to date there is no system which analyzes cl...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/33/11/1931

    authors: Schwenk M,Gogulla S,Englert S,Czempik A,Hauer K

    更新日期:2012-11-01 00:00:00

  • Development of a novel method for assessing balance: the quantitative posturography system.

    abstract::Balance is the ability to maintain equilibrium while sitting or standing. There are a number of different methods which are used to assess balance: technical methods such as sway magnetometry, ataxia meter and force platforms, and clinical methods such as the functional reach test, Berg balance test and fall risk inde...

    journal_title:Physiological measurement

    pub_type: 杂志文章

    doi:10.1088/0967-3334/21/4/309

    authors: Browne J,O'Hare N

    更新日期:2000-11-01 00:00:00

  • Gastric activity studies using a magnetic tracer.

    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

    pub_type: 临床试验,杂志文章

    doi:10.1088/0967-3334/25/5/015

    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