Initial filtration rate and initial clogging in the Hemorheometre.

The role of different factors contributing to red cell filterability in the Hemorheometre has been investigated. Although the original method uses a small volume of suspension to determine red cell filterability, the present experiments showed that the results obtained are still significantly affected by filter clogging. Consequently a change in filterability could be due to a change in filter clogging possibly by residual leucocytes. An adaptation of filter chamber and filling method is described, resulting in a simpler and faster measuring procedure. The inaccuracy in measuring low haematocrits contributes significantly to experimental errors. Therefore a definition of red cell filterability based on the red cell count (instead of haematocrit) of the suspension is suggested.