The nasal air sampler: a device for sampling inhaled aeroallergens

Objective: The object is to design, develop, and test a personal aerosol sampling device consisting of impaction samplers worn just inside the nostrils, driven by the wearer's respiration. The device provides a novel and unique measure of individual exposure to aeroallergens. It was conceived as an integral part of an allergen diagnostic system, in which collected aerosols are immunostained with monoclonal antibodies or the patient's IgE and associated particles positively identified using techniques of image analysis. Methods: Each sampler comprises a slot impactor with a detachable impaction plate covered with either a specially developed medical adhesive or a protein-binding membrane. Sampler performance has been validated by rig tests of aerodynamic resistance and collection efficiency of different sized particles at various flow rates. There have also been field trials with human subjects which show that the sampler can be comfortably worn for periods of up to 4 hours. This is sufficient to gather a representative sample of inhaled allergens in most environments. Results: The sampler collects an increasing proportion of particles in the inhalable range at and above 5 mu m. This includes most bioaerosols of interest to allergists. Sampler prototypes have been built by CNC mill and stereolithography. Batches of samplers have been molded in biocompatible materials for field and clinical trials. Conclusions: The device successfully collects aeroallergens from a patient's own respiration. While developed specifically as a vehicle for the allergen diagnostic system, it can be adapted for studies of other aspects of air quality or for prophylactic use.