Abstract: A method and apparatus for testing the efficacy of agents (e.g., new drugs, old drugs, biologically-active agents, etc.) by removing a predetermined amount of blood from a living being and placing this predetermined amount of blood in continuous motion in a temperature-controlled environment and then removing samples from the continuously-moving predetermined amount of blood. The drug, or drugs, or agents under test can then be administered to the removed samples, instead of into the living being, thereby avoiding subjecting the living being to any risk of any adverse reaction while utilizing blood samples that simulate the circulating blood of the living being.

Abstract: A method for isolating the effects of surface tension and/or yield stress of a fluid that is flowing in a U-shaped tube wherein one or both legs of the U-shaped tube is monitored over time for the changing height of the respective fluid columns therein. A portion of the U-shaped tube comprises a flow restrictor, e.g., a capillary tube, of known dimensions. Monitoring one or both of the moving fluid columns over time permits the determination of the viscosity of the fluid flowing therein over a range of shear rates from the difference in fluid column heights. However, it is necessary to isolate the effects of surface tension and/or yield stress to obtain an accurate viscosity determination. The method provides one manner in which the surface tension effect can be subtracted from the difference in fluid column heights and then any yield stress effect can then be determined.

Abstract: An apparatus and method for determining the viscosity of the circulating blood of a living being over plural shear rates caused by a decreasing pressure differential by monitoring the changing weight of the blood, or the changing level of a column of blood over time. The apparatus and method utilize a riser, a capillary tube, a collector and a mass detector, such as a precision balance or a load cell, for monitoring the changing weight of a sample of fluid that flows through these components under the influence of the decreasing pressure differential; alternatively, the apparatus and method use a column level detector to monitor the changing level of the column of blood over time.