Abstract: The Reduced Oxygen Breathing Device (ROBD2) is an apparatus that dilutes the oxygen present in air to concentrations below 21% by mixing the air with nitrogen. The purpose of this dilution is to simulate the reduced oxygen concentration available as one ascends in altitude. The ROBD2 is unique and different from previous devices that reduce the concentration of oxygen in room air via dilution with nitrogen gas in that it uses sophisticated gas regulating devices known as mass flow controllers. The ROBD also employs a gas extraction device as an independent component of the system that can separate nitrogen gas from air for use in the device.

Abstract: The present invention includes a non-rebreathing circuit coupled with computer-controlled gas adjustments. Ambient air is diluted with nitrogen on a breath-by-breath basis to provide precise control over the inspired concentration of oxygen/nitrogen mixture, thereby simulating selected altitudes on an almost instantaneous basis. Carbon dioxide and water vapor exhaled by the subject are released into the environment and absorption is not necessary. In addition, the mixed gas can be administered through a standard aviator's oxygen mask, increasing the realism of the simulation and removing obvious external cues on the nature of the experiment. Maintenance on the mixing loop is low when compared to re-breathing units, since no consumable items are necessary to absorb water vapor or carbon dioxide. A mixing device provides a homogenized mixture of nitrogen/oxygen fluid to the subject.

Abstract: The present invention includes a non-rebreathing circuit coupled with computer-controlled gas adjustments. Ambient air is diluted with nitrogen on a breath-by-breath basis to provide precise control over the inspired concentration of oxygen/nitrogen mixture, thereby simulating selected altitudes on an almost instantaneous basis. Carbon dioxide and water vapor exhaled by the subject are released into the environment and absorption is not necessary. In addition, the mixed gas can be administered through a standard aviator's oxygen mask, increasing the realism of the simulation and removing obvious external cues on the nature of the experiment. Maintenance on the mixing loop is low when compared to re-breathing units, since no consumable items are necessary to absorb water vapor or carbon dioxide. A mixing device provides a homogenized mixture of nitrogen/oxygen fluid to the subject.