Medical studies in aviation ...American Medical Association, 1918 - 69 pages |
Common terms and phrases
9 per cent ability acceleration accommodation administration of oxygen Air Service air staleness ammeter ascent athletic aviator blood flow blood pressure breathing cardiovascular circulatory CIRCULATORY SYSTEM color vision compensate condition convergence coronary circulation DECREASING OXYGEN SUPPLY deficiency of oxygen diastolic pressure dilatation diplopia effects of altitude effects of oxygen efficiency examined experiment factors failure fainting fall fatigue feet feet-from flying heart rate heart strain hemoglobin high altitudes important increase indicate KNIGHT DUNLAP light low oxygen tension low oxygen test low-pressure chamber lowered marked Medical Research Laboratory Mineola motor normal observations occurs organs oxygen deficiency oxygen percentage oxygen tension effect oxygen want percentages of oxygen petrous bone physiologic pilot pressure chamber psychologic pulse pressure pulse rate rapid ratus reac reactor rebreathing apparatus rebreathing test reduced response rheostat sensitivity stimulus lamps subnormal systolic pressure test object tion tympanic cavity U. S. Army vasomotor vasomotor control visual acuity
Popular passages
Page 41 - As instances of tests involving perception and discrimination, we may cite the copying of a list of work and the translation of words into code. In both of these cases speed and accuracy are maintained up to the final stages of asphyxiation, provided the muscular mechanism of accommodation and convergence are not seriously affected, although the mechanism for handwriting may be so affected that the...
Page 26 - ... pressure during a rebreathing test remains fairly constant in most men until the oxygen has fallen to between 12 and 9 per cent (14,500—22,000 feet), after which it increases in amount during the further reduction in oxygen. The rise in pulse pressure occurs when the systolic pressure is rising and the diastolic either remaining constant or slowly falling. This is also the period when the heart beat is accelerating most rapidly.
Page 58 - Normal three-minute runs as controls were made without the low oxygen tension effect ; then three-minute runs with approximately the same time interval were made in the lowpressure chamber and on the rebreathing apparatus. The findings on the rebreathing apparatus and in the low-pressure chamber showed a more rapid onset of fatigue than occurred with the controls. At 15,000 feet and at 20,000 feet the fatigue was marked, as was the case with accommodation. Here also the administration of oxygen caused...
Page 44 - ... washer; a green check lamp and a red error lamp; and a stylus with a hard rubber handle and metal tip. These parts of the unit are so wired electrically that when a stimulus lamp lights the corresponding contact button is " alive," and if touched with the metal tip of the stylus causes the check lamp to light.
Page 24 - Such sudden falls in the diastolic pressure appear to be due to an overcoming of the vasomotor center by oxygen shortage. A decided fall in the diastolic pressure even if more or less definitely controlled is an indication that the subject will not tolerate well the altitude corresponding to the oxygen percentage at which it appears. Three types of circulatory reaction to oxygen want have been observed. The first, the optimum, in which the pulse rate accelerates moderately as the oxygen decreases,...
Page 17 - The majority of men examined show at per centages of oxygen between 8 and 0 per cent an increase of 5.5 liters over the volume breathed at the beginning of the experiment. This increase gives for the average man a total volume of breathing per minute of approximately 14 liters at oxygen tensions corresponding to an altitude of 25,000 feet. The total per minute volume of air breathed has, in exceptional cases, been as great as 26 and 37 liters of air at oxygen tensions corresponding to from 25,000...
Page 7 - To investigate all conditions which affect the efficiency of pilots. 2. To institute and carry out, at flying schools or elsewhere, such experiments and tests as will determine the ability of pilots to fly in high altitudes. 3. To carry out experiments and tests, at flying schools or elsewhere, to provide suitable apparatus for the supply of oxygen to pilots in high altitudes.
Page 7 - ... pilots at high altitudes. 4. To act as a standing medical board for the consideration of all matters relating to the physical fitness of pilots.
Page 20 - A total increase of from fifteen to forty beats in the heart rate during a rebreathing test, in which the oxygen is lowered in half an hour to between 7.5 and 6.5 per cent., constitutes a good reaction to oxygen want.
Page 44 - ... in series with a third rheostat underneath the table. A two-way lever switch mounted underneath the table at the edge next to the psychologist, and a rocking pedal two-way switch on the floor under the table, are connected with the rheostat by a three-wire system, so that a part of the resistance of the rheostat can be cut out (thus increasing the speed of the motor) by either switch and again cut in (thus restoring the lower motor speed) by either switch.