Performance of A Portable Oxygen Breathing System At 25000 Feet Altitude

摘要

A portable oxygen system utilizing open port dilution rebreathing mask technology was tested for its ability to deliver an adequate supply of oxygen at an altitude of 25,000 feet above sea level. Twenty-two subjects, 11 females and 11 males, participated in the study. Blood oxygen saturation (SaO_2) baseline levels for hypoxic exposure were established for each subject. Altitude testing consisted of the subject being placed in a hypobaric chamber and it being decompressed to an altitude of 25,000 feet. Immediately after the start of the decompression, the subject was instructed to don the oxygen mask and start the flow of oxygen from the protable cylinder. Oxygen flow to the mask was continuous at 4 liters per minute. Once at altitude, the subjects pedaled a cycle ergometer at a resistance of 15 watts for five minutes. SaO_2 and other physiological variables were monitored throughout the altitude exposure. SaO_2 levels were maintained at ground level values for all subjects throughout the altitude exposures. At no point during the testing did oxygenation levels approach baseline levels for hypoxic exposure. The portable oxygen system tested provide protection from hypobaric hypoxia at an altitude of 25,000 feet.