Patent ID: 7814909
Filing Date: 2010-10-19
Classification: A62B

Abstract:
1. A method of reducing an inhaled concentration of carbon dioxide when using a full breathing mask placed on the face of a wearer, wherein the full breathing mask includes an inner face mask and an outer face mask, the method comprising: delivering breathing gas first to the outer face mask and then to the inner mask; directing exhalation gas to flow through the inner face mask prior to being released from the full breathing mask; and impeding leakage of the exhalation gas from the inner face mask to the outer face mask during an exhalation phase, by causing the entire perimeter of the inner face mask to lie in direct sealing abutment with the face of the wearer by bringing a free end of an intermediate wall into abutment with the inner face mask, wherein the intermediate wall extends from an inside of the outer face mask and a lower part of the inner face mask extends from a convex side of the intermediate wall to a concave side of the intermediate wall.