Mathematical and physical modelling of the dynamic fluidic impedance of arteries using electrical impedance equivalents

Giannoukos, Georgios; Min, Mart

doi:10.1002/mma.2829

Cited by 3 publications

(2 citation statements)

References 4 publications

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“…Meanwhile, for the electrode-electrolyte interface, the amplitude of the CPE exponent (α e ) is gradually increased during occlusion and a sudden stepwise fall was observed during the reperfusion state, while the CPE coefficient (Q e ) demonstrates the opposite effect (sudden stepwise fall during occlusion and a gradual decrease during reperfusion) across the electrode-electrolyte interface. This may be due to the movement of ions (as indicated in figure 4) and/or the polarization effect of membrane permeability (Giannoukos and Min 2014, Zhao et al 2017, Moqadam et al 2018. For the Cole-Cole model, the values of R 0 and the CPE coefficient (Q t and Q e ) of tissue and the values of the electrode-electrolyte interface were found to increase gradually during occlusion and decrease stepwise during reperfusion, while the values of R ∞ and the amplitude of the CPE exponent (α t ) for tissue components are decreased during occlusion and increased in reperfusion.…”

Section: Impedance Modelingmentioning

confidence: 99%

Changes in electrolyte concentrations alter the impedance during ischemia-reperfusion injury in rat brain

et al. 2019

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Objective: Ischemic stroke is a major cause of death and disability worldwide. Nowadays, electrical impedance spectroscopy is an emerging tool to differentiate between normal and stroke conditions. Approach: In this study, changes in the bio-impedance spectroscopy using a two-electrode method with varying frequencies from 100 to 35 kHz have been assessed in a model of global cerebral ischemia in anesthetized rats during normal, occlusion and reperfusion conditions. Global cerebral ischemia was induced by bilateral common carotid artery occlusion for 40 min following 40 min of reperfusion. The concentration of sodium, potassium, calcium and chloride ions in the whole rat brain was determined by electrolyte analyzer. For the interpretation of in vivo results, changes in electrical impedance with varying concentrations of sodium, potassium and calcium ions in artificial cerebrospinal fluid (aCSF) were also observed using the bio-impedance spectroscopy method. Main results: The in vivo bio-impedance analysis suggests that the impedance is consistently increased during occlusion as compared to the normal condition. The in vitro study revealed that the impedance escalates with an increase in the concentration of potassium and calcium ions and reduces with an increase in the concentration of sodium ions in aCSF. A further electrolyte analysis suggested that the level of sodium and chloride ions is significantly decreased and the level of calcium and potassium is significantly increased during occlusion as compared to the normal condition. Significance: These findings suggest that the increase in impedance during occlusion may be due to changes in the ionic concentration of the rat brain. The above in vivo and in vitro studies successfully demonstrated and interrelated the change in impedance with corresponding changes in ionic concentration.

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Section: Impedance Modelingmentioning

confidence: 99%

Changes in electrolyte concentrations alter the impedance during ischemia-reperfusion injury in rat brain

et al. 2019

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“…Their research proves that the hemodynamics of coronary arteries is characterized by a discernible and counter rotatory circular flow structure, whose topological properties are related to geometry. Recently, some research works studied the effects of various parameters and biological conditions on LDL concentration and flow fields such as, non‐Newtonian effect, the role of the fluidic impedance of an artery, fluid‐structure interactions, and hyperthermia and coupling effects …”

Section: Introductionmentioning

confidence: 99%

Effects of pulsatile flow and straight length on low‐density lipoprotein transport in a curved arterial wall

Tamim

Abbassi

Fatouraee

2020

Math Methods in App Sciences

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Abnormal accumulation of macromolecules such as low-density lipoproteins (LDLs) in the arterial wall causes narrowing and blockage of vessels, which leads to atherosclerosis. Effects of pulsatile nature of blood flows as well as the initial length on transport of the LDL species in the arterial boundary layer region are analyzed numerically in the present work. The set of governing equations consisting of continuity, Navier-Stokes, and species transport is solved using a projection method based on the second-order central difference discretization. The obtained results are in excellent agreement with the pertinent data. The computational results imply that the flow field and concentration distribution are time dependent but the variation of the filtration velocity can be ignored. The LDL concentration boundary layer thickness decreases in the outer part and increases in the inner part for both with or without straight length. Presence of initial straight length generates about 26% growth in the boundary layer thickness, although its effect on the LDL surface concentration (LSC) is negligible. The maximum LSC is related to the regions with minimum wall shear stress in the inner part of the curved artery, which have more potential for formation of atherosclerosis. A new numerical correlation between the LSC and boundary layer thickness is proposed and examined. K E Y W O R D Sfinite difference scheme, low-density lipoprotein transport, projection method, pulsatile flow, wall shear stress

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A Review on Carotid Ultrasound Atherosclerotic Tissue Characterization and Stroke Risk Stratification in Machine Learning Framework

Sharma

Gupta

Kumar

et al. 2015

Curr Atheroscler Rep

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Cardiovascular diseases (including stroke and heart attack) are identified as the leading cause of death in today's world. However, very little is understood about the arterial mechanics of plaque buildup, arterial fibrous cap rupture, and the role of abnormalities of the vasa vasorum. Recently, ultrasonic echogenicity characteristics and morphological characterization of carotid plaque types have been shown to have clinical utility in classification of stroke risks. Furthermore, this characterization supports aggressive and intensive medical therapy as well as procedures, including endarterectomy and stenting. This is the first state-of-the-art review to provide a comprehensive understanding of the field of ultrasonic vascular morphology tissue characterization. This paper presents fundamental and advanced ultrasonic tissue characterization and feature extraction methods for analyzing plaque. Additionally, the paper shows how the risk stratification is achieved using machine learning paradigms. More advanced methods need to be developed which can segment the carotid artery walls into multiple regions such as the bulb region and areas both proximal and distal to the bulb. Furthermore, multimodality imaging is needed for validation of such advanced methods for stroke and cardiovascular risk stratification.

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Mathematical and physical modelling of the dynamic fluidic impedance of arteries using electrical impedance equivalents

Cited by 3 publications

References 4 publications

Changes in electrolyte concentrations alter the impedance during ischemia-reperfusion injury in rat brain

Changes in electrolyte concentrations alter the impedance during ischemia-reperfusion injury in rat brain

Effects of pulsatile flow and straight length on low‐density lipoprotein transport in a curved arterial wall

A Review on Carotid Ultrasound Atherosclerotic Tissue Characterization and Stroke Risk Stratification in Machine Learning Framework

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