This work develops an empirical method for investigation of the flow properties of blood and applies it to a clinically oriented problem. The development focuses on the characterization of the flow properties of a blood sample. According to the theory of continuum mechanics the steady state flow properties of a material are characterized completely by its constitutive (Burchfield, 1972) function which relates the shear stress measured in a rheometer to the shear rate and hematocrit of the sample. Eleven functions derived from various sources were examined for their ability to fit flow data from thirty—one normal individuals, eleven of whom were using oral contraceptives. (The remainder were not using any drugs). A shear rate range of 0.0312 to 124 s⁻¹ was used at hematocrits from 0.29 to 0.55. A non-linear curve fitting procedure allowed an ordering of the functions to be established with respect to their goodness of fit. The function first employed by Walburn and Schneck (1976), T = X₁ exp (X₂ H+X₄ /H²)D[sup 1-X₃] where T = shear stress, D = shear rate, H = hematocrit and X₁ to X₄ are adjustable parameters, was found to be the most successful.
This constitutive function was then used to examine data obtained from a population of normal women at various times during the menstrual cycle, as a hemorheological cycle had been reported to occur over this period. The concentrations of several plasma proteins were also determined and plotted over time. No evident cycle of hemorheological properties or protein concentrations was found. / Medicine, Faculty of / Pathology and Laboratory Medicine, Department of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/21365 |
| Date | January 1979 |
| Creators | Easthope, Peter Lyall |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| Rights | For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use. |
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