By studying the blood viscosity from 313 healthy people, 90 patients with hypertension, 20 patients with cerebral vascular accident (CVA) and 9 patients with polycythemia Vera (PV). The authors found that: The blood viscosity of the health people is from 3.21-5.19. The blood viscosity of the patients with hypertension is from 3.38-5.82. There was no difference from the viscosity of the health people (p>0.01). The blood viscosity of the patients with CVA is from 4.43-7.13; and of the patients with PV is from 6.31-7.87; Both of them are significantly difference from the viscosity of the healthy people (p<0.05 and p<0.01 respectively).
Blood Viscosity ; epidemiology ; blood

The objective of the current study is to investigate the effect of physical vibration on blood viscosity. The "capillary tube viscometer concept" is applied to measure blood viscosity. Blood viscosity can be measured at the minimum shear rate of 12 s(-1) by the capillary tube viscometer. To examine the effect of physical vibration on blood viscosity, the vibrations are produced by contact with an electronic speaker. The frequencies of vibration are varied from 0 to 1000 Hz. The experimental results show that blood viscosity can be effectively reduced by applying vibration. Blood viscosity decreases as much as 10~12 % by applying vibration.
Blood Viscosity ; Capillaries ; Vibration

Malignant tumor have hypoxic cell fraction, which makes radio-resistant and hypoxia in tumor is a result from the blood flow decrease caused by increase in blood flow resistance. Blood viscosity increase is major factor of increased blood flow resistance and it could be attributed to the decrease in blood deformability index. For the evaluation of the change of blood viscosity and blood deformability in oral squamous cell carcinoma, we perform the test of the change of those factors between the normal control group and oral squamous cell carcinoma cell patient group. Relative viscosity measured against distilled water was 5.25+/-0.14 for normal control group, and 5.78+/-0.26 for the SCC patient group and there was statistical significance between the groups. However, there was no significant difference between the groups in blood viscosity between the groups by tumor size (T1+T2 vs T3+T4). Also, there was no significant difference between the normal control group and SCC patient group in blood deformability index and between the groups by tumor size (T1+T2 vs T3+T4). Increase in blood viscosity was confirmed with this study and it can be postulated that modification blood viscosity might contribute to decrease of hypoxia fraction in oral squamous cell carcinoma, thus improve the effect of radiotherapy and it can be assumed that the main factor of blood viscosity increase is not decrease of blood deformability in oral squamous cell carcinoma.
Anoxia ; Blood Viscosity* ; Carcinoma, Squamous Cell* ; Humans ; Radiotherapy ; Viscosity ; Water

No abstract available.
Blood Viscosity* ; Hydroxymethylglutaryl-CoA Reductase Inhibitors*

As there is justification showing that Poiseuille's Law is not suited for vertical Capillary tube viscometer, Poiseuille's Law has not been used to deduce the calculation formula for measuring liquid viscosity by means of vertical Capillary tube viscometer; it can only be used to deduce the calculation formula for measuring liquid viscosity by horizontal capillary tube viscometer. In this article, we explained the extension of Poiseuille's Law to deduce the Calculation formula for measuring liquid viscosity by using shallow pool and deep pool Capillar tube viscometer, and so corrected the mistakes in using Poiseuille's Law for a long time.
Blood Viscosity ; Hematologic Tests ; instrumentation ; Hemorheology ; Humans

No abstract available.
Blood Viscosity* ; Paraproteinemias* ; Plasma Cells* ; Plasma*

BACKGROUND: Whole blood viscosity (WBV) refers to the internal resistance that occurs when blood flows through blood vessels. WBV is known to be related to many diseases including cardiovascular and neurovascular diseases. We have investigated the analytical performance and established reference intervals for a newly developed microfluidic viscometer, Viscore-300 (NanoBiz, Korea), used for the measurement of WBV. METHODS: We performed a precision test of 240 measurements over 20 days using three control materials. For evaluation of repeatability, a total of 60 WBV measurements were made in 3 whole blood samples 20 times a day. A total of 100 whole blood samples were used to evaluate the accuracy of the Viscore-300 in comparison to a rotating viscometer, DV3T (Brookfield, USA), in accordance with the the Clinical and Laboratory Standards Institute's guidelines. To establish the reference intervals, 122 healthy individuals were enrolled in this study. RESULTS: The precision and repeatability results showed that the CV was less than 5% for three samples and two shear rates. In the accuracy test, the mean differences between two viscometers were 0.09 cP (0.9%) and −0.07 cP (−1.4%) at shear rates of 10 s−1 and 300 s−1, respectively. The reference intervals of WBV for men were 6.88–13.52 cP at 10 s−1 and 4.32–6.43 cP at 300 s−1; those of women were 5.74–13.29 cP at 10 s−1 and 3.60–6.12 cP at 300 s−1. CONCLUSIONS: Viscore-300 showed excellent precision and accuracy and it might be a good instrument for reporting WBV quickly and accurately.
Blood Vessels ; Blood Viscosity ; Female ; Humans ; Male ; Microfluidics

It has been suggested that normal tension glaucoma could be the result of pressure independent factors. One of the current theories is that normal tension glaucoma is the result of decreased optic nerve perfusion on the basis of vascular disease or other systemic factors such as altered blood viscosity or coagulation state. This study compared the vascular viscosity profiles, coagulation tests, and biochemical tests of 30 consecutive cases of normal tension glaucoma with 30 control cases to evaluate association of particular systemic state with normal tension glaucoma in Korean population. The data of total cholesterol and low density lipoprotein (LDL) cholesterol were significantly higher in the normal tension glaucoma group than in the control group. But there were no significant differences between the two groups with respect to the many other factors examined. These results support the vascular ischmic theory due to hyperlipidemia in the pathogenesis of the normal tension glaucoma. Inadequate circulation of optic nerve due to atherosclerotic change might play an important role in the pathogenesis of normal tension glaucoma.
Blood Viscosity ; Cholesterol ; Hyperlipidemias ; Lipoproteins ; Low Tension Glaucoma* ; Optic Nerve ; Perfusion ; Vascular Diseases ; Viscosity

OBJECTIVE: The objective of this study was to analyze patient-specific blood flow in ruptured aneurysms using obtained non-Newtonian viscosity and to observe associated hemodynamic features and morphological effects.METHODS: Five patients with acute subarachnoid hemorrhage caused by ruptured posterior communicating artery aneurysms were included in the study. Patients’ blood samples were measured immediately after enrollment. Computational fluid dynamics (CFD) was conducted to evaluate viscosity distributions and wall shear stress (WSS) distributions using a patient-specific geometric model and shear-thinning viscosity properties.RESULTS: Substantial viscosity change was found at the dome of the aneurysms studied when applying non-Newtonian blood viscosity measured at peak-systole and end-diastole. The maximal WSS of the non-Newtonian model on an aneurysm at peaksystole was approximately 16% lower compared to Newtonian fluid, and most of the hemodynamic features of Newtonian flow at the aneurysms were higher, except for minimal WSS value. However, the differences between the Newtonian and non-Newtonian flow were not statistically significant. Rupture point of an aneurysm showed low WSS regardless of Newtonian or non-Newtonian CFD analyses.CONCLUSION: By using measured non-Newtonian viscosity and geometry on patient-specific CFD analysis, morphologic differences in hemodynamic features, such as changes in whole blood viscosity and WSS, were observed. Therefore, measured non-Newtonian viscosity might be possibly useful to obtain patient-specific hemodynamic and morphologic result.
Aneurysm ; Aneurysm, Ruptured ; Blood Viscosity ; Hemodynamics ; Humans ; Hydrodynamics ; Intracranial Aneurysm ; Rupture ; Subarachnoid Hemorrhage ; Viscosity

Packed erythrocytes (PC) are used to treat intraoperative blood loss and frequently re- constituted with normal saline (NS) to overcome the slow infusion rate due to high viscosity and inadequate volume replacement. It has been recommended that calcium containing solutions such as Hartmann's solution (HS) should not be used as a diluent of PC, citing possible clot formation whenever the level of ionized calcium reaches a concentration capable of catalyzing the coagulation cascade. We studied in vitro coagulation propensity, if any, by analyzing the mixtures of PC with different amounts of HS or NS in ratios between 10: 0 to 1: 9 (PC: crystalloids). These mixtures were analyzed for ionized calcium concentration, pH, Hct and checked for the gross indication of clot formation at room temperature. No clot formation was found in NS-reconstituted samples, however, 55 of 100 HS-reconstituted samples were present with clot formation. In these samples, the initial clot formations were found at ratios of 6: 4 (1case at 45 min), 5: 5 (1 case at 45 min, 1 case at 60 min, 3 cases at 90 min), 4: 6 (1 case at 45 min, 3 cases at 60 min) and the mean ionized calcium concentration of initial clotting was 0.304+/-0.089 mM/L In conclusion, as much as 100ml of Hartmann's solution can be safely usedas a diluent of one unit of PC in patients requiring rapid blood transfusion.
Blood Transfusion ; Calcium ; Erythrocytes* ; Humans ; Hydrogen-Ion Concentration ; Viscosity