| abstract |
A rebreather apparatus for negating temporary hearing threshold shifts due to noise exposure and other physiological conditions related to CO 2 concentration. One embodiment of rebreather is formed with three chambers. A mouthpiece communicates with a first chamber and this chamber has limited access to the second chamber sandwiched thereto. A third chamber is sandwiched to the second chamber and has limited communication with the second chamber. The third chamber has limited communication therefrom to the atmosphere thus providing an elongated air pathway from the atmosphere to the mouthpiece. This elongated pathway with the restrictions of the openings between chambers achieves an accumulation of carbon dioxide from a user's breath. Accordingly, air inhaled from the rebreather elevates the carbon dioxide content in the lungs of a user and thus in the blood stream of the user. In another embodiment, the outer (third) chamber is collapsible during nonuse so that the rebreather may be carried in the pocket of the user and the second and third chambers have two portions symmetrically positioned on opposite surfaces of the first chamber. In another embodiment, at least the second and third chambers are collapsible. In a further embodiment, the rebreathing device comprises two collapsible chambers. The device is made from inexpensive materials so that, if desired, it may be disposed of after use. |