Rheologics, Inc.

Drexel University

Sehyun Shin

Young I Cho

Sangho Kim

Kenneth R Kensey

William N Hogenauer

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.

Single riser/single capillary blood viscometer using mass detection or column height detection

An apparatus and method for determining the viscosity of a fluid over plural shear rates caused by a decreasing pressure differential by monitoring the movement of the fluid through a riser tube and a capillary tube. The movement can be monitored by detecting the changing weight of the fluid, using a precision balance or load cell, as it moves through the riser tube and capillary tube into a fluid collector; or, alternatively, the movement can be monitored by detecting the changing level of a fluid column in the riser tube using a column level detector. A processor then uses the changing weight or height data, along with the dimensions of the capillary tube and a dimension of the riser tube, to determine the viscosity of the fluid. In addition, apparatus and methods for determining fluid viscosity online and fluid mixture homogeneity online are also described.

Single riser/single capillary viscometer using mass detection or column height detection

A scanning rheometer is presented for the Theological property measurement of electrorheological (ER) and magnetorheological (MR) fluids using a non-linear viscoplastic model, based on the fluid height variation with respect to time. The rheometer basically includes a static (e.g., an overhead reservoir) or a dynamic source of fluid, a channel or slit whose sides form electrodes which are in contact with the flowing ER fluid, or a capillary tube exposed to a static/alternating magnetic field for flowing MR fluids, a transfer tube, either one or two riser tubes, and a column level detector for monitoring the column of fluid as it moves in one of the riser tubes. The column level detector is coupled to a processor which analyzes, among other things, column height vs. time data to determine both viscosity and yield stress. The rheometer overcomes one of the major drawbacks of the conventional rheometer: the inability to produce the yield stress of the ER, or MR, fluid in an absolute zero shear rate range. The results with this rheometer are compared with those obtained from a commercially-available rheometer which indicates excellent agreement.

Electrorheological and magnetorheological fluid scanning rheometer

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. Alternatively, the method also provides a process by which both the surface tension effect and yield stress effect can be determined simultaneously.

Growing community of inventors

Bryn Mawr, PA, United States of America

Sehyun Shin