ABSTRACT
According as partial dog's physiological parameter observing in airtight cabin under normal air pressure, when the oxygen concentration is normal or low, tentatively estimate the important effect of oxygen concentration on dog's circulatory system and respiratory system, and then ascertain the vital significance of micro-circumstance regulating system to improving personnel's physiological function in cockpits and passengers' cabins of armoured vehicles, naval vessels, aircrafts, etc. Micro-circumstance regulating system under the conditions of airtight cabin is designed, a single-chip microprocessor 89C51, oxygen and carbon dioxide concentration transducers form its nucleus primarily, the function involve automatically monitoring and feedbackly regulating oxygen and carbon dioxide concentration all the time.