Abstract: Systems and devices for detecting and characterizing stratified fluid and/or aerosol particles and droplets, and methods of use thereof to, for example, diagnose and prognose respiratory diseases and disorders are provided. The systems typically include optoelectronic sensors for detecting foreign particles like bacteria and pollutants in the air (i.e., the aerosol) based on light scattering. Information collected in this way can be used to, for example, detect or identify respiratory maladies and determine the effectiveness of methods of treatment thereof.