| 摘要 |
<p>The apparatus is fitted with a bag (1) into which exhaled air is breathed. Its volume can be adjusted via the spindle (3). On inhaling, the air is passed through a C02 filter(2) made of calcium hydroxide. The percentage of oxygen in the air can be adjusted by altering the bag volume via the spindle. If the volume in the bag is smaller than the exhaled air the overflow is blown into the atmosphere via the pressure relief valve. On inhaling, the difference between the air in the bag and that in the lungs is evened out by introducing fresh air using a vacuum swing valve. The smaller the volume contained by the bag in relation to the volume of the lungs, the higher the proportion of oxygen and vice versa. It has a safety mouthpiece fitted with bite notches to keep it on the mouth connected to a hose with valves on each side.</p> |
