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Biomedical subjects

L R Iseev

Publications and source records attributed to L R Iseev.

7 recordsLinked to original sources
PubMedDate not supplied

[Changes in the maximum permissible supersaturation coefficient in altitude decompression].

This paper presents experimental data obtained during 383 altitude chambers tests in which 70 subjects participated. The purpose of the tests was to verify experimentally the safety of altitude decompression regimens that simulated transition from the orbital station atmosphere at a normal barometric pressure to the space suit oxygen atmosphere at a lowered pressure. The results help better understand correlations between the maximal allowable super-saturation coefficient and total postdecompression pressure.

Adult↗
PubMedDate not supplied

[Comparative study of decompression-induced formation of gas bubbles using ultrasonic equipment and the development of altitude-decompression disorders].

442 altitude experiments on 40 volunteers were performed. Gas bubbles in venous blood were detected using an ultrasonic Doppler system functioning in a continuous mode at a frequency of 5 MHz. The threshold of bubble formation was identified in 31 test subjects and that of emergency of altitude-decompression disorders, in 28 test subjects. Individual resistance to decompression-induced bubbles was revealed. It was shown that the thresholds may vary with time, in the head-down position and in the head-down position combined with exercises. A correlation was established between the rate of intravascular bubble formation and the frequency of altitude-decompression disorders.

Adult↗
PubMedDate not supplied

[Sensitivity of the respiratory regulatory apparatus to CO2 under simulated space flight conditions].

Using the rebreathing method, CO2 sensitivity of the respiration regulation system was investigated during a year-long enclosure study and head-down tilt tests of varying duration (up to 120 days). During the exposures CO2 and H+ were built up in the body. In the course of the enclosure study CO2 sensitivity was reduced. During bed rest experiments this parameter changed differently: it increased on day 7 and significantly decreased on days 55 to 100. These findings show that respiration regulation may vary markedly and indicate that it is worthwhile to carry out similar investigations in an actual space flight.

Adult↗
PubMedDate not supplied

[Analysis of clinical symptoms of cases of human decompression disease in altitude chamber studies].

Over 2400 altitude chamber ascents in which 130 volunteers participated were performed using different decompression tables. The cases of decompression disease were classified in terms of its types and severity. It is stressed that the experiments involved in decompression studies have to be extremely careful because the disease may have various and sudden manifestations.

Decompression Sickness↗
PubMedDate not supplied

[Relation between the probability of development of altitude-decompression disorders and the duration of pre-exposure to a hypobaric atmosphere].

Healthy volunteers, aged 21-47 years, were kept in an altitude chamber. Before decompression to a residual pressure of 293.3 GPa the test subjects were consecutively exposed to 1120 GPa for 2 hrs and then to 733.3 GPa for 24, 18 or 12 hrs. At 293.3 GPa the test subjects performed a moderate workload for 6 hrs. It has been concluded that prior to the use of a space suit with the working pressure 0.3 kgf/cm2 (293.3 GPa) the time of exposure to a hypobaric normoxic (29-30% O2) atmosphere with the total barometric pressure 733.3 GPa should not be less than 18 hrs and it should preferably be 24 hrs. In this situation decompression safety of 6-hr extravehicular activity can be predicted with a high probability.

Adaptation, Physiological↗