A rapid response microviscosimeter

Kirby, Gerald S.; Church, Timothy S.; Beecherl, E E; Barron, O. Alton; Smith, Jessie; Terkildsen, M W

doi:10.1016/s0006-355x(98)00030-4

Cited by 3 publications

(3 citation statements)

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“…developed a rapid response viscometer using two 41 (µm) tubes connected in series that measures blood viscosity more rapidly and reliably than the conventional and other capillary type of microviscometers [11]. But still this system needed long procedure to get usable data, and very long hours for manual data input.…”

Section: Discussionmentioning

confidence: 99%

“…By this means, effective viscosity and flow rate are continuous on-line output variables which can be directly obtained from PC records of only P 0 and P 1 , both being gauge pressures relative to atmosphere pressure (P 2 ) [11].…”

Section: A Theorymentioning

confidence: 99%

“…Applied to the microviscometer, Hagen-Pouiseuille relation yields both µ e (effective viscosity) and Q (flow rate) of the sample in place. Throughout the system these parameters are functions of measured pressure drops, system geometry (C), and the reference viscosity µ R of the fluid (saline) in the reference section (1) and (2):Where Q is volumetric fluid flow rate, µ is viscosity, L is tube length, and tube radius is R.By this means, effective viscosity and flow rate are continuous on-line output variables which can be directly obtained from PC records of only P 0 and P 1 , both being gauge pressures relative to atmosphere pressure (P 2 ) [11]. …”

mentioning

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An automated real time capillary viscometer

Usta

Özkan²

2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society

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Abstract-This study describes how to establish a capillary viscometer (microviscosimeter) that uses an inline microflowmeter that can accurately measure whole blood effective viscosity in tubes of arteriolar diameter at physiologically nominal flow rates with all benefits of digital media. Total measurement time is 4 minutes. The data can be digitally handled. Currently this system is assembled at the Department of Anatomy, Istanbul Medical School, University of Istanbul. The system diagnoses elevated viscosity as a routine procedure providing valuable criteria for many clinical manifestations. Keywords -Capillary viscometer, microviscometer, blood viscosity I. INTRODUCTIONViscosity as a hemorheological criteria has become far more important after the clinicians started to blame it for some pathological conditions. There is a bunch of study showing that the blood viscosity is apparently relevant with erythrocyte aggregation, endothelial damage, intimal thickening, coronary artery disease and diabetic ischemia.Clinical manifestations of coronary and cerebrovascular disease are associated with an increased blood viscosity [1,2]. Plasma viscosity is predictive of ischemic heart disease events in a free-living population [3] and progression to acute myocardial infarction in patients with unstable angina pectoris [4]. Abnormalities in blood rheology, including elevations of blood and plasma viscosity, are related to vascular complications in Diabetes Mellitus [5].The rise in blood viscosity accounts for clinical manifestations of Polycythemia that have been observed in approximately 50 % of newborn infants with hematocrit values of 0.65 or greater. In neonates, hyperviscosity increases the risk of pulmonary hypertension, renal failure, necrotizing enterocolitis, cerebral ischemia, intracranial hemorrhage, and developmental retardation [6][7][8][9][10].Currently, most of the researchers have used very conventional types of viscometers (cone-in-cone or cone-onplate) or newer or developing systems such as ball or capillary types for measuring blood and plasma viscosity. Among all these type of viscometers, capillary type of viscometers seem to be more reliable than the others, because the blood flows in vessels that have similar geometry and size with capillary tubes of these instruments.The capillary viscometer created by Kirby [11] is closer to the physiological system, because of the velocitycontrolled nature of his instrument.Kirby's system consisted of three parts; capillary tubes, transducers and amplifers, and a paper-chart recorder.Kirby collects at least 38 data from paper chart by counting squares. Surely, this method is very slow, inaccurate and impractical. Also, it yields high observation error, limited number of data points, and low accuracy. To overcome the handicaps of this system's time consuming third part, we proposed a digital system. II. METHODOLOGY A. TheoryWhen fluid is flowing steadily through the entire system, the modified Hagen-Pouiseuille flow relationship holds throughout the flow system su...

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Section: Discussionmentioning

confidence: 99%

Section: A Theorymentioning

confidence: 99%

mentioning

confidence: 99%

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An automated real time capillary viscometer

Usta

Özkan²

2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society

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Hereditary coagulation factor VII deficiency caused by novel compound heterozygous mutations in a Chinese pedigree: A case report

Cai

et al. 2022

Clinical Laboratory Analysis

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Background Congenital coagulation factor VII (FVII) deficiency is a rare, autosomal‐recessive haemorrhagic disorder with an estimated incidence of 1:500,000. This disorder is caused by mutations in the F7 gene. Case description Here, we report a pedigree of congenital FVII deficiency. The proband was a 30‐year‐old female with severely low FVII activity and a history of menorrhagia and epistaxis since her childhood who was subsequently diagnosed with congenital compound heterozygous FVII deficiency. A genetic study revealed a novel combination of compound heterozygous mutations (c.64G 〉 A, p.Gly22Ser and c.1027G 〉 A, p.Gly343Ser). Her father and older son had the c.64G 〉 A, p.Gly22Ser (heterozygous) mutation. Her mother and younger son had the c.1027G 〉 A, p.Gly343Ser (heterozygous) mutation. The predicted results of PolyPhen‐2 and MutationTaster indicated that these mutations were probably damaging and disease‐causing, respectively. Conclusion In this study, we identified a novel combination of genetic mutations that could expand the mutant library and help in elucidating the pathogenesis of hereditary human coagulation FVII deficiency. A novel combination of compound heterozygous mutations was reported for the first time in Chinese individuals.

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