Antigen exposure chamber systems configured so as to supply a predetermined amount of antigen to expose a subject to the antigen have been used for experiments and researches relating to diseases such as allergy.
Conventional antigen exposure chamber systems include ones provided with a ceiling air supply port and a ceiling air exhaust port at the ceiling of the chamber, or an air supply port at the ceiling of the chamber and an air exhaust port at the lower portion of the chamber walls, thereby generating an air flow flowing between the air supply port and the air exhaust port and mixing an antigen supplied from the outside of the chamber into this air flow. However, each of them has an extremely non-uniform antigen concentration distribution in the chamber (for example, see Non-Patent Document 1).
Furthermore, there are no measures to prevent an antigen from flowing out of the chamber more than making the chamber pressure to be a negative pressure, which is extremely insufficient for preventing an antigen from flowing out of the chamber, so there has been the possibility that an antigen flows to the outside of the antigen exposure chamber.
Also, when a measuring device is installed outside the exposure chamber, a sampling tube is used to take sample antigen concentrations in the chamber. However, there are various kinds of materials for sampling tubes for the conventional antigen exposure chamber systems, and there are no fixed arrangement routes for such sampling tubes, and compensation of the measured values has not been made. Accordingly, there is a problem in that the loss of antigen particles is so large that an accurate concentration measurement cannot be conducted, depending on the material, the length or the bent portion count of the tube.    Patent Document 1: None    Non-Patent Document 1: N. Krug et al., Validation of an environmental exposure unit for controlled human inhalation studies with grass pollen in patients seasonal allergic rhinitis, Clinical & Experimental Allergy, Vol. 33, No. 12, p.p. 1667-1674, December 2003