Electrostatic precipitation of exhaled particles for tensiometric examination of pulmonary surfactant

Collecting exhaled particles that represent small droplets of the alveolar lining fluid shows great promise as a tool for pulmonary surfactant (PS) sampling. In this work we present a setup consisting of two modules, namely, a module for droplet collecting, called an electrostatic aerosol trapping (ESAT) system, and a measurement module for studying PS properties. We also suggest a method to extract numerical values from experimental data. The operating principle of ESAT is based on electrostatic precipitation of exhaled particles. Native material was collected directly on the water surface, where the adsorbed pulmonary surfactant film was investigated by the tensiometric method. The modified capillary wave method proposed in our previous work was adapted for studying small-volume samples. The efficiency of the setup was verified in the experiments involved the participation of healthy subjects. The accumulation of PS components on the water surface in an amount sufficient for tensiometric study was reported. The idea underlying the new concept used in this work may give impetus to the development of point-of-care facilities for collecting PS samples needed to provide their express analysis.