[Characteristics of human external respiration under excess intrapulmonary pressure under sea level and "altitude" conditions according to pneumotachographic data].

In 54 pressure chamber experiments 12 healthy male test subjects took part. Their pneumotachograms and other physiological parameters at a positive pressure breathing of 30 mm Hg at sea level and of 125--130 mm Hg at an altitude of 25,000 m at rest and while exercising were recorded. High altitude facilities and pneumotachograph were modified to meet the experimental requirements. The changes in pneumotachographic readings depended on the excess intrapulmonary pressure, its variations with respect to the respiratory stages, efficiency of the external counterpressure on the body, as well as motor activity of the test subjects. The pneumotachographic procedure allows qualitative and quantitative evaluations of external respiration upon excess intrapulmonary pressure, and study of the mechanism of these changes supported by other physiological methods.