主权项 |
1. A facial breathing mask, suitable for regulating carbon dioxide concentration in inspired air as well as a depth and rate of breathing, said facial mask comprising in combination:
a primary air chamber having a surface and a primary opening in said primary air chamber through which a user can breathe, at least one semi-permeable membrane in the surface of said primary air chamber, separating said primary air chamber and a surrounding atmosphere, wherein a diffusion rate of carbon dioxide through the semi-permeable membrane is lower than a diffusion rate of a different gas through the semi-permeable membrane to thereby retain carbon dioxide within the mask, at least one flexible air chamber in fluid connection with said primary air chamber, said at least one flexible air chamber having a volume which can expand and contract according to a mass of air inside said at least one flexible air chamber, wherein the facial breathing mask is configured to raise carbon dioxide tension in the inspired air. |