Dielectric analysis of blood by means of a raster-electrode technique

Dielectric measurements were made on blood samples containing erythrocytes of varying diameter D and percentage p. For effective measurements of the conductivity γ and the dielectric constant ε, in the frequency range f=10–100 kHz electrode effects were corrected by means of a raster-electrode technique, which is based on the automatic variation of the effective electrode area. The results, which proved to be independent of f, indicate that an increase of haematocrit p is linked with a strong decrease of γ, being essentially independent of D. For low and medium p an increase of ε, resulted from increasing p. For physiological values of p close to 40 per cent, a strong increase of ε, was found with increasing D, indicating possibilities of using the method for rapid determination of D in addition to p. For very high values of p (>60 per cent) ε, showed a distinct decrease. This finding is discussed using a cube model for the particle suspension.

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