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Mehri, Rym; Laplante, Jérémie; Mavriplis, Catherine; Fenech, Marianne

doi:10.5405/jmbe.1695

Cited by 15 publications

(5 citation statements)

References 12 publications

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“…This speckle analysis enables one to measure EA under relatively various hematocrit conditions, compared to other techniques based on image-processing techniques. 10,[27][28][29] Figs. 1(d) and 1(e) show the temporal variations of intensity distribution along with the channel width (y/W Half ), speckle area (A Speckle ) for RBCs suspended in plasma-dextran mixture with a concentration of 0.06% (Ht ¼ 40%), and injection flow rate (Q) of the syringe pump.…”

Section: The Proposed Methods To Measure Ea Based On Speckle Analmentioning

confidence: 99%

“…To measure the number of RBCs in an aggregate, the area of each rouleaux in binary images was divided by the mean area of a single RBC. Similar to Mehri's method, 29 each aggregate in binary images is labeled for better distinction. The binary images were obtained by thresholding with an optimal value evaluated by using the Otsu's algorithm.…”

Section: E Microscopic Observation For Ea Measurementmentioning

confidence: 99%

“…10,27 By employing the Mehri's image-processing method and micro-particle image velocimetry (micro-PIV) technique, information about the size and flow velocity of RBC aggregates in the micro channel were simultaneously measured. 28,29 Although direct assessment techniques can figure out the size and dynamic motions of rouleaux, the hematocrit of blood samples should be adjusted to less than 10% for accurate quantification of EA. 12,30 Consequently, the degree of EA has mostly been measured indirectly under various physiological conditions.…”

Section: Introductionmentioning

confidence: 99%

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Microfluidic-based speckle analysis for sensitive measurement of erythrocyte aggregation: A comparison of four methods for detection of elevated erythrocyte aggregation in diabetic rat blood

Yeom

Lee

2015

Biomicrofluidics

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Biochemical alterations in the plasma and red blood cell (RBC) membrane of diabetic blood lead to excessive erythrocyte aggregation (EA). EA would significantly impede the blood flow and increase the vascular flow resistance contributing to peripheral vascular diseases. In this study, a simple microfluidic-based method is proposed to achieve sensitive detection of hyperaggregation. When a blood sample is delivered into the device, images of blood flows are obtained with a short exposure time for a relatively long measuring time. A micro-particle image velocimetry technique was employed to monitor variation of the flow rate of blood as a function of time. Given that EA formation in the channel creates clear speckle patterns, the EA extent can be estimated by calculating a speckle area (ASpeckle) through a normalized autocovariance function. The hematocrit effect is assessed by comparing optical images transmitted through blood samples. EA variations caused by dextran treatment are quantitatively evaluated using characteristic time (λSpeckle) obtained by fitting the variations of ASpeckle. Other indices including number of RBCs in an aggregate (NRBC), characteristic time of erythrocyte sedimentation rate (λESR), and aggregation index estimated from ultrasound signals (AIEcho) are determined under different EA conditions using conventional techniques. The four different methods are applied to diabetic blood samples to compare their indices under hyperaggregation conditions. It is found that the proposed method can detect variation of EA reasonably, compared with conventional measurement techniques. These experimental demonstrations support the notion that the proposed method is capable of effectively monitoring the biophysical properties of diabetic blood.

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Section: The Proposed Methods To Measure Ea Based On Speckle Analmentioning

confidence: 99%

Section: E Microscopic Observation For Ea Measurementmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Microfluidic-based speckle analysis for sensitive measurement of erythrocyte aggregation: A comparison of four methods for detection of elevated erythrocyte aggregation in diabetic rat blood

Yeom

Lee

2015

Biomicrofluidics

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“…RBC aggregation is a physiological phenomenon; however, it is found significantly elevated in various pathologies because of its sensitivity to inflammation-sensitive proteins (mainly fibrinogen). The distribution of aggregates in microscale blood flows has been recently quantified using image processing techniques; it has been shown that, in general, the size of aggregates in the flow is exponentially distributed (Mehri et al, 2014 andKaliviotis et al, 2017). Furthermore, the distribution of aggregates in bifurcations has been found to be influenced by their spatial distribution in the feeding branch and by the flow conditions in the outlets of the bifurcation (Kaliviotis et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

Local viscosity distribution in bifurcating microfluidic blood flows

2018

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The red blood cell (RBC) aggregation phenomenon is majorly responsible for the non-Newtonian nature of blood, influencing the blood flow characteristics in the microvasculature. Of considerable interest is the behaviour of the fluid at the bifurcating regions. In vitro experiments, using microchannels, have shown that RBC aggregation, at certain flow conditions, affects the bluntness and skewness of the velocity profile, the local RBC concentration, and the cell-depleted layer at the channel walls. In addition, the developed RBC aggregates appear unevenly distributed in the outlets of these channels depending on their spatial distribution in the feeding branch, and on the flow conditions in the outlet branches. In the present work, constitutive equations of blood viscosity, from earlier work of the authors, are applied to flows in a T-type bifurcating microchannel to examine the local viscosity characteristics. Viscosity maps are derived for various flow distributions in the outlet branches of the channel, and the location of maximum viscosity magnitude is obtained. The viscosity does not appear significantly elevated in the branches of lower flow rate as would be expected on the basis of the low shear therein, and the maximum magnitude appears in the vicinity of the junction, and towards the side of the outlet branch with the higher flow rate. The study demonstrates that in the branches of lower flow rate, the local viscosity is also low, helping us to explain why the effects of physiological red blood cell aggregation have no adverse effects in terms of in vivo vascular resistance.

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“…In this paper, we present the methodology used to identify, assess and characterize human RBC aggregation subjected to controlled and measurable shear rates in a two-fluid flow microfluidic shearing system (microchannel of 110 × 60 µm 2 ) (Mehri et al 2014(Mehri et al , 2015 using image processing techniques. The methodology was first tested on known diameter hollow glass microspheres and validated by comparing results with the diameters and size distribution obtained provided by the manufacturer.…”

Section: Introductionmentioning

confidence: 99%