scholarly journals Red blood cell (RBC) aggregation and its influence on non-Newtonian nature of blood in microvasculature

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Chitra Murali ◽  
Perumal Nithiarasu
Keyword(s):  
Blood Flow ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Cell Aggregation ◽  
Time Dependent ◽  
Shear Rates ◽  
Red Blood Cell Aggregation ◽  
Significant Difference ◽  
Rbc Aggregation ◽  
Rouleaux Formation

AbstractA robust computational model is proposed to investigate the non-Newtonian nature of blood flow due to rouleaux formation in microvasculature. The model consists of appropriate forces responsible for red blood cell (RBC) aggregation in the microvasculature, tracking of RBCs, and coupling between plasma flow and RBCs. The RBC aggregation results have been compared against the available data. The importance of different hydrodynamic forces on red blood cell aggregation has been delineated by comparing the time dependent path of the RBCs. The rheological changes to the blood flow have been investigated under different shear rates and hematocrit values and quantified with and without RBC aggregation. The results obtained in terms of wall shear stress (WSS) and blood viscosity indicate a significant difference between Newtonian and powerlaw fluid assumptions.

scholarly journals Numerical simulation of spatiotemporal red blood cell aggregation under sinusoidal pulsatile flow

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cheong-Ah Lee ◽  
Dong-Guk Paeng
Keyword(s):  
Shear Rate ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Pulsatile Flow ◽  
Cell Aggregation ◽  
Spatiotemporal Variation ◽  
Shear Rates ◽  
Red Blood Cell Aggregation ◽  
Axial Shear ◽  
Rbc Aggregation

AbstractPrevious studies on red blood cell (RBC) aggregation have elucidated the inverse relationship between shear rate and RBC aggregation under Poiseuille flow. However, the local parabolic rouleaux pattern in the arterial flow observed in ultrasonic imaging cannot be explained by shear rate alone. A quantitative approach is required to analyze the spatiotemporal variation in arterial pulsatile flow and the resulting RBC aggregation. In this work, a 2D RBC model was used to simulate RBC motion driven by interactional and hydrodynamic forces based on the depletion theory of the RBC mechanism. We focused on the interaction between the spatial distribution of shear rate and the dynamic motion of RBC aggregation under sinusoidal pulsatile flow. We introduced two components of shear rate, namely, the radial and axial shear rates, to understand the effect of sinusoidal pulsatile flow on RBC aggregation. The simulation results demonstrated that specific ranges of the axial shear rate and its ratio with radial shear rate strongly affected local RBC aggregation and parabolic rouleaux formation. These findings are important, as they indicate that the spatiotemporal variation in shear rate has a crucial role in the aggregate formation and local parabolic rouleaux under pulsatile flow.

scholarly journals On the use of photoacoustics to detect red blood cell aggregation

2021 ◽  
Author(s):  
Michael C. Kolios
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Spectral Power ◽  
Aggregate Size ◽  
Cell Aggregation ◽  
Dominant Frequency ◽  
Red Blood Cell Aggregation ◽  
Theoretical Predictions ◽  
Rbc Aggregation ◽  
Simulation Results

The feasibility of detecting red blood cell (RBC) aggregation with photoacoustics (PAs) was investigated theoretically and experimentally using human and porcine RBCs. The theoretical PA signals and spectra generated from such samples were examined for several hematocrit levels and aggregates sizes. The effect of a finite transducer bandwidth on the received PA signal was also examined. The simulation results suggest that the dominant frequency of the PA signals from non-aggregated RBCs decreases towards clinical frequency ranges as the aggregate size increases. The experimentally measured mean spectral power increased by ~6 dB for the largest aggregate compared to the non-aggregated samples. Such results confirm the theoretical predictions and illustrate the potential of using PA imaging for detecting RBC aggregation.

Effects of increased plasma viscosity and red blood cell aggregation on blood viscosity in vivo

1981 ◽  
Vol 241 (4) ◽  
pp. H513-H518 ◽  
Author(s):  
L. Gustafsson ◽  
L. Appelgren ◽  
H. E. Myrvold
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Apparent Viscosity ◽  
Cell Aggregation ◽  
Plasma Viscosity ◽  
Pressure Flow ◽  
Red Blood Cell Aggregation ◽  
Rbc Aggregation

The effects of increased plasma viscosity and induced red blood cell (RBC) aggregation on apparent viscosity of blood in vivo in the skeletal muscle of the dog were studied. Apparent viscosity in vivo was determined in the isolated and vasodilated calf muscles of one hindlimb by comparing pressure-flow relationships for RBC suspensions with pressure-flow relationships for a Newtonian solution of known viscosity. RBC suspensions of increased plasma viscosity with and without RBC aggregation were obtained by substituting plasma with isoviscous solutions of high- and low-molecular-weight dextran in saline. Hematocrits of the suspensions were adjusted to either 45 or 60%. The viscosities of the suspensions in vitro were determined in a Wells-Brookfield viscometer. Apparent viscosity of blood in vivo was found to be mainly dependent on the viscosity of plasma. RBC aggregation had no significant influence on the viscosity in vivo.

Effects of red blood cell aggregation on the blood flow in a symmetrical stenosed microvessel

2019 ◽  
Vol 19 (1) ◽  
pp. 159-171 ◽  
Author(s):  
L. L. Xiao ◽  
C. S. Lin ◽  
S. Chen ◽  
Y. Liu ◽  
B. M. Fu ◽  
...  
Keyword(s):  
Blood Flow ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Cell Aggregation ◽  
Red Blood Cell Aggregation ◽  
Blood Cell Aggregation
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