Design and analysis of an instrument system for rheological testing of whole blood samples

The dissertation covers the conceptual design of a rheometer for testing whole blood samples through to the clotting state. While the design aims at increased measurement accuracy, the design employs well known technologies and available components. The main reason for preoccupation with blood testing is that recent investigations have indicated that physiological disorders can be correlated with rheological properties of blood. The pursuit of an improved means of correlation is initiated with a survey of the rheological properties of blood. The relevance of these blood properties is then discussed. From this discussion a broader blood model is developed as a guide to design of a special blood rheometer. The contribution of this work is an engineering study of the exploitation of known technologies to produce a rheometer which permits more precise measurement of fluid properties by better quantization of instrument errors. The quantization of instrument errors inherently requires new and original analysis of sample holder geometry, mathematical treatment of sample holder geometry for Newtonian fluids, discussion of exact and end effect characteristics of solutions of sample holder geometry for Newtonian fluids. Further reduction in errors are achieved by the control of sample holder motions (through management of motions in discrete steps), a flexible digital control of required motions, and a method for obtaining transient responses and fast time constants for torque measurement using a conventional counter torque servo system