Non-Newtonian Rheology in Blood Circulation

Sochi, Taha

doi:10.48550/arxiv.1306.2067

Cited by 6 publications

(7 citation statements)

References 57 publications

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“… 43 – 45 In addition to yield stress and the other non-Newtonian rheological behaviors of blood, this action can promote thrombosis and pathological blockages seen in CVDs such as strokes. 46 …”

Section: Discussionmentioning

confidence: 99%

Trends among platelet function, arterial calcium, and vascular function measures

Cunha,

Chan,

Nkambule

et al. 2023

Platelets

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Arterial tonometry and vascular calcification measures are useful in cardiovascular disease (CVD) risk assessment. Prior studies found associations between tonometry measures, arterial calcium, and CVD risk. Activated platelets release angiopoietin-1 and other factors, which may connect vascular structure and platelet function. We analyzed arterial tonometry, platelet function, aortic, thoracic and coronary calcium, and thoracic and abdominal aorta diameters measured in the Framingham Heart Study Gen3/NOS/OMNI-2 cohorts ( n = 3,429, 53.7% women, mean age 54.4 years ±9.3). Platelet reactivity in whole blood or platelet-rich plasma was assessed using 5 assays and 7 agonists. We analyzed linear mixed effects models with platelet reactivity phenotypes as outcomes, adjusting for CVD risk factors and family structure. Higher arterial calcium trended with higher platelet reactivity, whereas larger aortic diameters trended with lower platelet reactivity. Characteristic impedance (Zc) and central pulse pressure positively trended with various platelet traits, while pulse wave velocity and Zc negatively trended with collagen, ADP, and epinephrine traits. All results did not pass a stringent multiple test correction threshold ( p < 2.22e-04). The diameter trends were consistent with lower shear environments invoking less platelet reactivity. The vessel calcium trends were consistent with subclinical atherosclerosis and platelet activation being inter-related.

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Section: Discussionmentioning

confidence: 99%

Trends among platelet function, arterial calcium, and vascular function measures

Cunha,

Chan,

Nkambule

et al. 2023

Platelets

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“…Moreover, blood is usually considered as a predominantly shear thinning fluid, especially under steady flow conditions (Fatahian et al, 2018). Thus, this property seems to have the most important non-Newtonian impact (Sochi, 2013). Having quickly considered a competitive analysis of the obtained modelled values in the literature, one is able to conclude that shear thinning is evaluated using the Carreau-Yasuda model, and yield stress is usually described by the Casson model (Yilmaz and Yaar Gundogdu, 2008;Sochi, 2013).…”

Section: Modeling Of the Capillary Blood Flowmentioning

confidence: 99%

“…Thus, this property seems to have the most important non-Newtonian impact (Sochi, 2013). Having quickly considered a competitive analysis of the obtained modelled values in the literature, one is able to conclude that shear thinning is evaluated using the Carreau-Yasuda model, and yield stress is usually described by the Casson model (Yilmaz and Yaar Gundogdu, 2008;Sochi, 2013). As it was mentioned above shear thinning is the most important property in the description of hemorheology and hemodynamics.…”

Section: Modeling Of the Capillary Blood Flowmentioning

confidence: 99%

Application of a multicomponent model of convectional reaction-diffusion to description of glucose gradients in a neurovascular unit

Nartsissov

2022

Front. Physiol.

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A supply of glucose to a nervous tissue is fulfilled by a cerebrovascular network, and further diffusion is known to occur at both an arteriolar and a microvascular level. Despite a direct relation, a blood flow dynamic and reaction-diffusion of metabolites are usually considered separately in the mathematical models. In the present study they are coupled in a multiphysical approach which allows to evaluate the effects of capillary blood flow changes on near-vessels nutrient concentration gradients evidently. Cerebral blood flow (CBF) was described by the non-steady-state Navier-Stokes equations for a non-Newtonian fluid whose constitutive law is given by the Carreau model. A three-level organization of blood–brain barrier (BBB) is modelled by the flux dysconnectivity functions including densities and kinetic properties of glucose transporters. The velocity of a fluid flow in brain extracellular space (ECS) was estimated using Darcy’s law. The equations of reaction-diffusion with convection based on a generated flow field for continues and porous media were used to describe spatial-time gradients of glucose in the capillary lumen and brain parenchyma of a neurovascular unit (NVU), respectively. Changes in CBF were directly simulated using smoothing step-like functions altering the difference of intracapillary pressure in time. The changes of CBF cover both the decrease (on 70%) and the increase (on 50%) in a capillary flow velocity. Analyzing the dynamics of glucose gradients, it was shown that a rapid decrease of a capillary blood flow yields an enhanced level of glucose in a near-capillary nervous tissue if the contacts between astrocytes end-feet are not tight. Under the increased CBF velocities the amplitude of glucose concentration gradients is always enhanced. The introduced approach can be used for estimation of blood flow changes influence not only on glucose but also on other nutrients concentration gradients and for the modelling of distributions of their concentrations near blood vessels in other tissues as well.

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“…Nevertheless, the current prevalent technology for BP measurement that provides continuous monitoring needs to be evolved further to make it accurate and reliable. The fact that blood has a non-Newtonian rheological characteristicis not given adequate attention in physiological studies and its effects are neglected in large lumen since shear rates are relatively very high (Sochi 2013). However, in many pathophysiological conditions like multiple myeloma, acute leukemia, rheumatoid disease, polycythemia vera, etc, its effect is significant in diagnosis.…”

Section: Introductionmentioning

confidence: 99%

Noninvasive cuffless blood pressure estimation using pulse transit time, Womersley number, and photoplethysmogram intensity ratio

et al. 2019

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Objective: Continuous cuffless blood pressure (BP) monitoring research has emerged as blood pressure is one of the dynamic parameters which reflects cardiac arrhythmias and rheological disorders without the drawbacks of current techniques. All the existing measurement techniques are cuff-based with drawbacks such as being discontinuous in nature, being uncomfortable for the patient, etc. Therefore, the goal is to develop an algorithm to estimate BP accurately using the pulse transit time (PTT), photoplethysmogram intensity ratio (PIR) and Womersley number (α) in a noninvasive way. Approach: The PTT technique holds the promise of real-time, cuffless, continuous BP monitoring in clinical settings. However, the non-Newtonian fluid nature of blood is considered insignificant in the conventional PTT model-based BP modeling. In the proposed work, α, representing viscous effects, along with PTT and PIR, is included in the algorithm since it is also one of the parameters that affects the BP. Main results: The proposed algorithm is evaluated with 42 healthy and 39 diseased subjects and compared with the other conventional techniques to evaluate the importance of viscous effects in BP, using performance metrics like mean ± standard deviation, and 95% confidence interval for bias and limits of agreement; a better estimate is achieved with the proposed algorithm. Significance: The proposed algorithm reflects the influences of vasomotor tone and baroflex as well, which makes it suitable for the assessment of BP in both healthy and diseased subjects, with improved accuracy than the current measurement techniques.

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Non-Newtonian Rheology in Blood Circulation

Cited by 6 publications

References 57 publications

Trends among platelet function, arterial calcium, and vascular function measures

Trends among platelet function, arterial calcium, and vascular function measures

Application of a multicomponent model of convectional reaction-diffusion to description of glucose gradients in a neurovascular unit

Noninvasive cuffless blood pressure estimation using pulse transit time, Womersley number, and photoplethysmogram intensity ratio

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