The present invention is related to the field of bio/chemical sensing, assays and applications. Particularly, the present invention is related to collecting a small amount of a vapor condensate sample (e.g. the exhaled breath condensate (EBC) from a subject of a volume as small as 10 fL (femto-Liter) in a single drop), preventing or significantly reducing an evaporation of the collected vapor condensate sample, analyzing the sample, analyzing the sample by mobile-phone, and performing such collection and analysis by a person without any professionals.

Brain activity, and in particular which hemisphere is relatively more effective, is correlated with the dominant nostril (i.e., the nostril through which most of the air is exhaled when breathing through the nose). Thus, identifying which of the nostrils is dominant may have various applications. Described herein are systems and methods for identifying the dominant nostril. In one embodiment, a system includes at least one inward-facing head-mounted thermal camera (CAM) and a computer. The at least one CAM does not occlude any of the user's mouth and nostrils and is used to take thermal measurements of first and second regions below the right and left nostrils (TH.sub.ROI1 and TH.sub.ROI2, respectively). The computer identifies the dominant nostril based on TH.sub.ROI1 and TH.sub.ROI2. Optionally, the computer detects, utilizing TH.sub.ROI1 and TH.sub.ROI2, the three-dimensional (3D) shape of the exhale stream from at least one of the nostrils.

The present invention relates to a method for allowing the filters for protecting against contamination during the passage of the air flow by the sensors in pulmonary function tests to homogeneously distribute the wrinkles of the mouthpieces during production. The present invention relates to the solution of the problems experienced because the filter does not shrink or sufficiently shrink the aperture where the filter is located due to the shrinkage of the mouthpiece taken from the mold produced after melting the plastic raw material in the mold, which protects the transceivers from contamination.