On the Formation and Physical Behaviour of Exhaled Particles

摘要: Aerosol particles are generated in human airways and leave the body with exhaled air. The originate from respiratory tract contain non-volatile compounds that potentially may be used as biomarkers for various medical conditions. To utilise any information provided by particles, they must characterised. work performed this thesis focuses on measuring concentrations size distributions of endogenous results give indications how where formed. Number obtained different individuals breathing techniques, were measured. show that inter-individual variation number concentration is very high, while distribution peaks at about same diameter all subjects. a smaller particle tidal than it does eaching airway closure. Moreover, deep exhalations result significantly higher breathing. Exhalation followed few seconds breath hold amplifies emitted subsequent exhalation, whereas after inhalation reduces concentration. It was also found quickly shrinks when leaves saturated environment inside surrounding lower relative humidity. The support theory created through film rupture process. Following closure inhalation, fluid films spanned across airways. These burst form next exhalation. suggested activates smallest produces particles. As exhalation depth increases, additional, larger close formed. Breath low lung volume extensive increased concentration, high causes deposition loss further supersaturated liquid droplets shortly leaving body.