• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.371-372
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• 2002

It is well known that red blood cells (RBCs) are suffered from chronic stresses in systemic circulation. The objective of this study is to clarify the effect of the aging of RBCs on rheological properties and hemolysis. Initially, RBCs age fractionation was performed by using a high-speed centrifugation (15[min] at 1500[G]), then young and aged RBCs were suspended in plasma to adjust the hematocrit level of 40[%]. After this pretreatment, the viscosity was measured by using a capillary type and a cone-plate type viscometers, respectively, and the hemolysis test was carried out by a seesaw type shaker. Results from these experiments showed that the viscosity of the aged RBCs measured by the capillary viscometer was increased by 10[%] as compared with that of the young RBCs. Under the condition of all shear zones, the viscosity of the aged RBCs was increased in case of using the cone-plate type viscometer. And the hemolytic level was increased twice as the aging. The data obtained in this study indicated that the ability of aggregation of RBCs was increased and the deformability of RBCs membrane got lower with the aging. Furthermore, it was exhibited that the fragility of RBCs ’ membrane was increased with the aging.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1510-1515
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• 2004

Aggregability of red blood cells (RBCs) was determined by a laser backscattering light analysis in a microfluidic channel. Available techniques for RBC aggregation often adopt a rotational Couette-flow using bob-and-cup system for disaggregating RBCs, which causes the system to be complex and expensive. A disposable microfluidic channel and vibration generating mechanism were used in the proposed new detection system for RBC aggregation. Prior to measurement, RBC aggregates in a blood sample were completely disaggregated by applying vibration-induced shear. With the present apparatus, the aggregation indexes of RBCs can be easily measured with small quantities of blood sample. The measurements with the present aggregometer were compared with those of LORCA and showed a strong correlation between them. The aggregability of the defibrinogenated blood RBCs is markedly lower than that of the normal RBCs. The noble feature of this design is the vibration-induced disaggregation mechanism, which enables to incorporate disposable element that holds the blood sample.

• Journal of the Optical Society of Korea
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• v.16 no.2
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• pp.115-120
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• 2012

In this paper, we present a method to automatically quantify the three-dimensional (3D) volume of red blood cells (RBCs) using off-axis digital holographic microscopy. The RBCs digital holograms are recorded via a CCD camera using an off-axis interferometry setup. The RBCs' phase image is reconstructed from the recorded off-axis digital hologram by a computational reconstruction algorithm. The watershed segmentation algorithm is applied to the reconstructed phase image to remove background parts and obtain clear targets in the phase image with many single RBCs. After segmenting the reconstructed RBCs' phase image, all single RBCs are extracted, and the 3D volume of each single RBC is then measured with the surface area and the phase values of the corresponding RBC. In order to demonstrate the feasibility of the proposed method to automatically calculate the 3D volume of RBC, two typical shapes of RBCs, i.e., stomatocyte/discocyte, are tested via experiments. Statistical distributions of 3D volume for each class of RBC are generated by using our algorithm. Statistical hypothesis testing is conducted to investigate the difference between the statistical distributions for the two typical shapes of RBCs. Our experimental results illustrate that our study opens the possibility of automated quantitative analysis of 3D volume in various types of RBCs.

• The Korean Journal of Blood Transfusion
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• v.29 no.3
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• pp.291-300
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• 2018

Background: The use of a functionally closed system for the glycerolization and deglycerolization of red blood cells (RBCs) allows for prolonged post-thaw storage for more than 24 hours. The aim of this study was to assess glycerolization and deglycerolization processing for RBCs using a high glycerol method in the automated, closed system provided by Haemonetics ACP 215. Methods: Thirty-five packed RBCs were glycerolized using the ACP 215 to a final concentration of 40% (wt/vol). The units were either frozen as such (n=30) or excess glycerol was removed (n=5) before freezing. After storage at $-80^{\circ}C$, the units were thawed, deglycerolized and resuspended in SAG-M. The frozen-thawed RBCs were stored at $4^{\circ}C$, and analyzed for their stability and in vitro quality. Results: No prefreeze excess glycerol removal units showed significantly less potassium leakage during post-thaw storage compared to the prefreeze excess glycerol removal units. All measurements of the stability and in vitro quality of thawed RBCs prepared from frozen RBCs without the prefreeze removal of excess glycerol during post-thaw storage at $4^{\circ}C$ for 7 days were acceptable to the American Blood Bank Association's standards and European standards. Conclusion: RBCs frozen without prefreeze removal of excess glycerol and the ACP 215 simplifies cryopreservation procedure and increases the stability of frozen-thawed RBCs. This increases the practical applicability of cryopreserved RBCs in blood transfusion practice.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1505-1509
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• 2004

The suspension of hardened red blood cells (RBCs) differs from the suspension of normal RBCs with respect to their rheological behavior. The deformability of normal and hardened RBCs (obtained by heating blood at $49^{\circ}C$ or by incubating RBCs in a solution of hydrogen peroxide) was measured with a slit diffractometer and RBC suspension viscosity was measured with a rotational viscometer. The peroxide-treated RBCs showed a significant decrease of the deformability and their suspension viscosity increased over a range of shear rates. The suspension viscosity of the heated RBCs, however, where the deformability is even lower than that of the peroxide-treated RBCs, was slightly higher than that of the normal RBC suspension in the high shear rates. The present study found that not all rigid cells cause an increase of blood viscosity at high shear rate, and therefore that decreased membrane deformability is not predictive of high-shear blood viscosity.

• Journal of Dental Anesthesia and Pain Medicine
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• v.15 no.4
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• pp.229-233
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• 2015

Background: Although water chambers are often used as surrogate blood-warming devices to facilitate rapid warming of red blood cells (RBCs), these cells may be damaged if overheated. Moreover, filtered and irradiated RBCs may be damaged during the warming process, resulting in excessive hemolysis and extracellular potassium release. Methods: Using hand-held syringes, each unit of irradiated and leukocyte-filtered RBCs was rapidly passed through a water chamber set to different temperatures (baseline before blood warming, $50^{\circ}C$, $60^{\circ}C$, and $70^{\circ}C$). The resulting plasma potassium and free hemoglobin levels were then measured. Results: Warming RBCs to $60^{\circ}C$ and $70^{\circ}C$ induced significant increases in free hemoglobin (median [interquartile ranges] = 60.5 mg/dl [34.9-101.4] and 570.2 mg/dl [115.6-2289.7], respectively). Potassium levels after warming to $70^{\circ}C$ ($31.4{\pm}7.6mEq/L$) were significantly higher compared with baseline ($29.7{\pm}7.1mEq/L$; P = 0.029). Potassium levels were significantly correlated with storage duration after warming to $50^{\circ}C$ and $60^{\circ}C$ (r = 0.450 and P = 0.001; r = 0.351 and P = 0.015, respectively). Conclusions: Rapid warming of irradiated leukoreduced RBCs to $50^{\circ}C$ may not further increase the extracellular release of hemoglobin or potassium. However, irradiated leukoreduced RBCs that have been in storage for long periods of time and contain higher levels of potassium should be infused with caution.

• Journal of Mechanical Science and Technology
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• v.19 no.3
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• pp.887-893
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• 2005

The aggregability of red blood cells (RBCs) was determined by laser backscattering light analysis in a microfluidic channel. Available techniques for RBC aggregation often adopt a rotational Couette-flow using a bob-and-cup system for disaggregating RBCs, which causes the system to be complex and expensive. A disposable microfluidic channel and vibration generating mechanism were used in the proposed new detection system for RBC aggregation. Prior to measurement, RBC aggregates in a blood sample were completely disaggregated by the application of vibration-induced shear. With the present apparatus, the aggregation indexes of RBCs can be measured easily with small quantities of a blood sample. The measurements with the present aggregometer were compared with those of LORCA and the results showed a strong correlation between them. The aggregability of the defibrinogenated blood RBCs is markedly lower than that of the normal RBCs. The noble feature of this design is the vibration-induced disaggregation mechanism, which can incorporate the disposable element that holds the blood sample.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1487-1491
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• 2008

Detailed knowledge on the motion of blood cells flowing in micro-channels under simple shear flow and the influence of blood flow is essential to provide a better understanding on the blood rheological properties and blood cell aggregation. The microscopic behavior of red blood cell (RBCs) is numerically investigated using a fluid-structure interaction (FSI) method based on the Arbitrary-Lagrangian-Eulerian (ALE) approach and the dynamic mesh method (smoothing and remeshing) in FLUENT (ANSYS Inc., USA). The employed FSI method could be applied to the motions and deformations of a single blood cell and multiple blood cells, and the primary thrombogenesis caused by platelet aggregation. It is expected that, combined with a sophisticated large-scale computational technique, the simulation method will be useful for understanding the overall properties of blood flow from blood cellular level (microscopic) to the resulting rheological properties of blood as a mass (macroscopic).

• Korea-Australia Rheology Journal
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• v.16 no.3
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• pp.129-134
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• 2004

The aggregation characteristics of red blood cells (RBCs) were measured using a newly developed light-transmission slit rheometer. Conventional methods of RBC disaggregation such as the rotational Couette system were replaced with a pressure-driven slit flow system with a vibrational mechanism. Using a vibration generator, one can disaggregate the RBC aggregates stored in the slit. While shear stress decreases exponentially, instantaneous pressure and the transmitted light intensity were measured over time. Applying an abrupt shearing flow after disaggregation caused a rapid elongation of the RBCs followed by loss of elongation with the decreasing shear stress. While the shear stress is further decreasing, the RBCs start to re-aggregate and the corresponding transmitted intensity increases with time, from which the aggregation indices can be obtained using a curve-fitting program.

• Korean Journal of Veterinary Research
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• v.39 no.4
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• pp.724-729
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• 1999

Amino acids, Na, K and glutathione (GSH) in red blood cells (RBCs) and hematological indices were examined in Korean dogs. A total of seven dogs possessing RBCs with high K and high glutathione (GSH)(HK/HG) were found in 42 Korean dogs : three from Cheju dog, two from Jindo dog and two from Korean mongrel. The RBCs in Korean HK/HG dog contained abnormally high aspartate (Asp), Glu and glutamine (Gln) the same as in HK/HG RBCs from Japanese Shiba dog. Two dogs possessing RBCs with HK and low GSH (HK/LG) were found in Cheju dog, and they accumulated Asp and Gln. Thus, not only the existence of HK dog was confirmed in Korean dogs, but HK/LG dog was also found. The Asp concentration in RBCs from seven of 33 LK dogs was more than $1000{\mu}mol/lc$, the same as in variant LK RBCs with defective Glu/Asp transport (LK/GAT), while it was less than $800{\mu}mol/lc$ in normal LK RBCs. Thus, there were variant dogs having RBCs with abnormally high amino acids accumulation among HK and LK Korean dogs.