Objective Evaluation of Nasal Dimensions in Children with Acoustic Rhinometry

Aims: This study was carried out to investigate the usefulness of acoustic rhinometry in the evaluation of intranasal dimensions in children. The aim was to define reference values for school children. In addition, the role of the VAS scale in the subjective evaluation of nasal obstruction in children was studied. Materials and methods: Measurements were done with Acoustic Rhinometry A1. The values of special interest were the minimal cross-sectional area (MCA) and the anterior volume of the nose (VOL). The data for reference values included 124 voluntary school children with no permanent nasal symptoms, aged between 7 and 14 years. Data were collected at baseline and after decongestion of the nose; the VAS scale was filled in before measurements. The subjects in the follow-up study (n=74, age between 1 and 12 years) were receiving intranasal spray of insulin or placebo. The nasal symptoms were recorded and acoustic rhinometry was measured at each control visit. Results: In school children, the mean total MCA was 0.752 cm2 (SD 0.165), and the mean total VOL was 4.00 cm3 (SD 0.63) at baseline. After decongestion, a significant increase in the mean TMCA and in the mean TVOL was found. A correlation was found between TMCA and age, and between TVOL and height of a child. There was no difference between boys and girls. A correlation was found between unilateral acoustic values and VAS at baseline, but not after decongestion. No difference wasfound in acoustic values or symptoms between the insulin and placebo group in the follow-up study of two years. Conclusions: Acoustic rhinometry is a suitable objective method to examine intranasal dimensions in children. It is easy to perform and well tolerated. Reference values for children between 7 and 14 years were established.

Slurry flows in progressive cavity and in hose pumps

The aim of this thesis was to research how slurry’s viscosity and rheology affect to pumping in peristaltic hose pump and in eccentric progressive cavity pump. In addition, it was researched the formed pressure pulsation in hose pump. Pressure pulsation was studied by pumping different slurries and by using different pipe materials. Pressure and power curves were determined for both used pumps. It was also determined NPSHR curve for the progressive cavity pump. Literature part of the thesis considered to distribute fluids to different rheology types, as well as theories and models to identify different rheology types. Special attention was paid to non-Newtonian fluids, which were also used in experimental part of this thesis. In addition, the literature part discusses about pumps, parameters for pump sizing, and pressure pulsation in hose pump. Starch, bentonite, and carboxymethyl cellulose slurries were used in the experimental part of this thesis. The slurries were pumped with Flowrox peristaltic hose pump (LPP-T32) and eccentric progressive cavity pump (C10/10). From the each slurry was taken a sample, and the samples were analyzed for concentration, viscosity and rheology type. The used pipe materials in pressure pulsation experiments were steel and elastic, and it was also used a prototype of pulsation dampener. The pulsation experiments indicated that the elastic pipe and the prototype of pulsation dampener attenuated pressure pulsation better than the steel pipe at low pressure levels. The differences between different materials disappeared when pressure level and pump rotation speed increased. In slurry experiments, pulsation was different depending on rheology and viscosity of the slurry. According to experiments, the rheology did not significantly affect to pump power consumption or efficiency.