Rheological properties of middle ear effusion and their role on mucociliary clearance

The viscoelastic properties of freshly harvested middle ear effusion (MEE) from children were determined by an oscillating sphere magnetic rheometer and compared with transportability of MEE on mucus-depleted frog palate. The elastic modulus (G') at 1 Hz of MEE from 43 untreated ear was ranged from 1.9 to 1,790 dyn/cm2 and the mean value was 28.4 dyn/cm2. The dynamic viscosity (eta') at 1 Hz of the same samples was ranged from 0.2 to 146 poise with the mean value of 3.4 poise. A maximum value of transport was obtained at G' of about 20 dyn/cm2, and below this value there was a significant positive correlation between the transport rate and log G'. Above 20 dyn/cm2, the negative correlation between the transport rate and log G' was significant. A similar significant correlation between the transport rate and log eta' was observed.