Topic
Rheoscope
About: Rheoscope is a research topic. Over the lifetime, 56 publications have been published within this topic receiving 2404 citations.
Papers published on a yearly basis
Papers
TL;DR: An optical technique is described whereby an observed quantitative output derived from a mesurement of light intensity through a spatial filter is related to the change in cellular dimensions that were previously observed under similar fluid-shear conditions by use of microscopy and a cone-plate viscometer (rheoscope).
Abstract: The laser light scattered by erythrocytes subjected to a well-defined shear stess can be analyzed with the ektacytometer to obtain information regarding the changes in cell shape due to fluid shear. We describe an optical technique whereby an observed quantitative output derived from a mesurement of light intensity through a spatial filter is related to the change in cellular dimensions that were previously observed under similar fluid-shear conditions by use of microscopy and a cone-plate viscometer (rheoscope). We also present the predictions of a theoretical model (of the ektacytometer) based on approximations of light-scattering theory developed for nonspherical particles, and give preliminary results for the accuracy and sensitivity of this measurement of erythrocyte deformability. With this optical technique the instrumentation (ektacytometer) is made quite simple and suitable for use in the typical laboratory. This would allow a regular, quantitative assessment of this important blood cell quality, to supplement the data obtained from the complete blood count.
143 citations
TL;DR: An improved “rheoscope” chamber with counterrotating cone and plate, which is suitable for in vitro studies of the microrheology of blood cells, is described and has brought to light characteristics of pathological red cell aggregation at intermediate rates of shear that have evaded viscometric analysis.
138 citations
TL;DR: Analysis of the data indicates that increases in membrane viscosity and elastic modulus along with a significant loss in excess surface area contribute to the limitation of the ability of the older cells to change shape.
135 citations
TL;DR: The automated rheoscope enabled the determination of RBC-DDs from which less deformable subpopulations can be established and may be valuable in assessing cell fractions with normal and anomalous deformability within pathologic blood samples.
Abstract: Background. Red blood cells (RBCs) have to deform markedly to pass through the smallest capillaries of the microcirculation. Techniques for measuring RBC deformability often result in an indication of the mean value. A deformability distribution would be more useful for studying diseases that are marked by subpopulations of less deformable cells because even small fractions of rigid cells can cause circulatory problems. Methods. We present an automated rheoscope that uses advanced image analysis techniques to determine a RBC deformability distribution (RBC-DD) by analyzing a large number of individual cells in shear flow. The sensitivity was measured from density-separated fractions of one blood sample and from cells rendered less deformable by heat treatment. A preliminary experiment included the RBC-DDs of a patient with sickle cell anemia, one on dialysis and being treated with erythropoietin, and one with elliptocytosis. Results. Measurement of the RBC-DD was highly reproducible. The sensitivity test showed markedly different deformability distributions of density-separated cells and yielded distinct RBC-DDs after each additional minute of heat treatment. Conclusion. The automated rheoscope enabled the determination of RBC-DDs from which less deformable subpopulations can be established. The shape of an RBC-DD may be valuable in assessing cell fractions with normal and anomalous deformability within pathologic blood samples. Cytometry (Clin. Cytometry) 50: 313‐325, 2002. © 2002 Wiley-Liss, Inc. Key terms: rheoscope; red blood cell; deformability distribution; heat treatment; image analysis; automated analysis
106 citations
TL;DR: Calcium accumulation by ionophore-CaCl2 takes place in preference to aged cells of lower energy metabolism, and leads to cellular dehydration and loss of deformability, due to condensed hemoglobin and altered membrane organization.
95 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2018 | 1 |
| 2016 | 2 |
| 2014 | 1 |
| 2011 | 1 |
| 2007 | 5 |
| 2006 | 4 |