Erythrometer: a new device for measuring erythrocyte filterability and plasma viscosity.

The Erythrometer is a new device capable of determining both red blood cell filterability and plasma viscosity. In the case of filterability measurements, a suspension of washed red blood cells is filtered at a steady flow rate through a 3 or 5 microns pore-diameter membrane. Pressure drop across the membrane is recorded and a red blood cell filterability index can be calculated according to the change in pressure. The authors describe the instrument's operating principle and performance and present some of the results obtained.