Patent ID: 8336547

Claim:
A breathing mask for a hyperbaric chamber comprising: a housing configured to form an inner volume, the housing comprising: an inlet configured to allow fluid flow into the inner volume; an exhaust configured to allow fluid flow from the inner volume; a posterior opening configured to provide fluid communication between the inner volume and a user's respiratory system; and first and second anterior openings extending through an anterior portion of the housing; a pneumatically-balanced exhaust valve configured to selectively flow fluid between the exhaust and the inner volume; a pneumatically-balanced demand valve configured to selectively flow fluid between the inlet and the inner volume, wherein each of the exhaust valve and the demand valve is configured to have a first bias, and wherein each valve is configured to pneumatically provide a second bias configured to reduce the amount of the first bias; a first diaphragm covering the first anterior opening; and a second diaphragm covering the second anterior opening, wherein the first and second diaphragms are configured to move in response to a change in pressure within the inner volume during inhalation and exhalation by a user; wherein the first diaphragm is mechanically linked to the exhaust valve such that the exhaust valve opens and closes in response to movement of the first diaphragm, and wherein the second diaphragm is mechanically linked to the demand valve such that the demand valve opens and closes in response to movement of the second diaphragm.