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Biomedical subjects

A D Egorov

Publications and source records attributed to A D Egorov.

At least 37 records · Page 2Linked to original sources
PubMed1988

Review of basic medical results of the Salyut-7--Soyuz-T 8-month manned flight.

This paper presents the results of medical investigations performed in the Salyut-7 8-month mission in which a professional physician took part. The paper contains anthropometric measurements, results of investigating the vestibular function, cardiovascular function at rest and in response to multi-step tests (with emphasis on echocardiographic measurements), metabolic parameters and hormonal status. It also discusses medical aspects of the extravehicular activity. The medical investigations, although some new methods were applied, provided the continuity of methodical approaches and data accumulated in previous missions.

Adaptation, Physiological↗
PubMed1988

Neurohumoral mechanism of space motion sickness.

This paper reviews existing hypotheses concerning the mechanisms of adaptation of the vestibular apparatus and related somatosensory systems to microgravity with reference to the flight data. Having in view theoretical concepts and experimental data accumulated in space flights, a conceptual model of the development of a funtional system responsible for the termination of vestibular dysfuntion and space motion sickness manifestations is presented. It is also shown that changes in the hormonal status during motion sickness induced by vestibular stimulation give evidence that endocrine regulation of certain functions can be involved in adaptive responses.

Adaptation, Physiological↗
PubMed1988

Central and regional hemodynamics in prolonged space flights.

This paper presents the results of measuring central and regional (head, forearm, calf) hemodynamics at rest and during provocative tests by the method of tetrapolar rheography in the course of Salyut-6-Soyuz and Salyut-7-Soyuz missions. The measurements were carried out during short-term (19 man-flights of 7 days in duration) and long-term (21 man-flights of 65-237 days in duration) manned missions. At rest, stroke volume (SV) and cardiac output (CO) as well as heart rate (HR) decreased insignificantly (in short-term flights) or remained essentially unchanged (in long-term flights). In prolonged flights CO increased significantly in response to exercise tests due to an increase in HR and the lack of changes in SV. After exercise tests SV and CO decreased as compared to the preflight level. During lower body negative pressure (LBNP) tests HR and CO were slightly higher than preflight. Changes in regional hemodynamics included a distinct decrease of pulse blood filling (PBF) of the calf, a reduction of the tone of large vessels of the calf and small vessels of the forearm. Head examination (in the region of the internal carotid artery) showed a decrease of PBF of the left hemisphere (during flight months 2-8) and a distinct decline of the tone of small vessels, mainly, in the right hemisphere. During LBNP tests the tone of pre- and postcapillary vessels of the brain returned to normal while PBF of the right and left hemisphere vessels declined. It has been shown that regional circulation variations depend on the area examined and are induced by a rearrangement of total hemodynamics of the human body in microgravity. This paper reviews the data concerning changes in central and regional circulation of men in space flights of different duration.

Adaptation, Physiological↗
PubMed1988

Ethical problems of interaction between ground-based personnel and orbital station crewmembers.

Manned missions onboard orbital stations Salyut-6 and Salyut-7 have led us to the conclusion that a long-term space mission can be viewed as a complex socio-man-machine system whose effectiveness largely depends on the quality of interaction between its subsystems. When analyzing and assessing the reliability of this system, it is important to consider ethical aspects, because they concern human relations, permeating its very component and in the long run determining its efficiency. Psychological and medical examinations before, during and after manned missions have helped us to identify the major points of interaction of the subsystems which require adequate monitoring and optimization using socio-psychological and organization-technical approaches: arrangement and evaluation of the quality of work, arrangement of proper leisure, psychological comfort in the interpersonality and intergroup relations during prolonged space missions. This paper also discusses adaptive changes in the mental and physical state due to prolonged exposure to space flight factors such as microgravity and confinement.

Adaptation, Psychological↗
PubMed1987

Medical problems of manned space flights onboard orbital stations.

Medical aspects of crew safety and life support as well as biomedical investigations form part and parcel of the preparation and conduct of manned space programs. The list of biomedical problems related to these programs is very long. The present paper concentrates on some of them.

Adaptation, Physiological↗
PubMed1983

Medical results of Salyut-6 manned space flights.

The major goal of medical investigations in the USSR longterm (up to 6 months) manned space flights was to accumulate information on human responses to prolonged weightlessness. Before, during and after these flights, detailed clinical, physiological, immunological and anthropometric examinations were conducted. The examinations demonstrated that man may well adapt to long-term space flight, retaining good health and a high work capacity. The changes seen postflight were reversible and disappeared completely after a relatively short readaptation period. Postflight changes did not correlate with the flight duration. A reasonable work-rest cycle and various physiological countermeasures were used, the efficiency of which were substantiated by means of regular medical examinations. These methods helped the cosmonauts to maintain good health status and adequate performance inflight and facilitated their readaptation postflight. Medical investigations performed during the Salyut-6 flights indicate that the duration of manned space flight can be increased.

Aerospace Medicine↗
PubMed1983

[Study of the phase structure of the cardiac cycle during the test with decompression of the lower part of the body in long-term (140-185 days) space flights].

Before and during prolonged space flights changes of systolic time intervals in response to LBNP tests were qualitatively similar and corresponded to the syndrome of myocardial hypodynamics due to insufficient venous return. However, the level of the changes and their contribution to the cardiac cycle were different in flight and on the ground. Greater changes in systolic time intervals seen in flight may be attributed to larger blood shifts to the abdomen and legs.

Blood Pressure↗
PubMed1981

[Results of a hemodynamic and cardiac cycle phase structure study in a functional test with measured physical load on a 140-day flight in the Saliut-6 station].

During the 140-day flight of the orbital station Salyut-6 two primary crewmembers performed 5 exercise tests on a bicycle ergometer at a load of 750 kgm/min for 5 min. During tests heart rate, and before and after tests arterial pressure, left ventricular chronograms and cardiac output (rheographically) were recorded. In comparison to the preflight tests, the flight tests were characterized by less expressed changes in phasic parameters, moderate increase in cardiac output and, occasionally, insufficient decrease in peripheral resistance. These changes can be attributed to the weightlessness-associated deficiency of the circulating blood volume.

Adaptation, Physiological↗
PubMed1980

Device for mass measurement under zero-gravity conditions.

The problem considered in this paper is the investigation of the properties of a mass-meter, i.e. the device for determining the mass of cosmonaut's body under zero-gravity conditions. The estimates of accuracy of mass measurement by this device are given, and the results of measuring the masses of cosmonauts' bodies on the Salyut 5 and 6 orbital stations are presented.

Aerospace Medicine↗
PubMed1977

Preliminary results of medical investigations during manned flights of the Salyut 4 orbital station.

In 1975 the Soviet Union performed two manned flights on board the orbital station Salyut 4. The first mission of 30 days was flown by A. A. Gubarev (Commander) and G. M. Grechko (Flight Engineer) and the second mission of 63 days by P.I. Klimuk (Commander) and V.I. Sevastyanov (Flight Engineer). The present paper gives preliminary data on the general health and cardiovascular investigations of the crew members during and after flight. The clinical and physiological examinations of the cosmonauts showed that the work-rest cycles and counter-measures used helped to maintain their good health and high performance in flight, to alleviate adverse reactions and to facilitate readaptation post-flight. Medical results of the post-flight investigations revealed no changes that may detract from further increasing the duration of manned space missions.

Adaptation, Physiological↗
PubMed1976

Results of medical investigations carried out on board the Salyut orbital stations.

The purpose of the medical investigations carried out in flights of the Soviet orbital station Salyut were: to further studies and clarification of the phenomenology and mechanisms of changes in the main functions of the human body during prolonged weightlessness; to accumulate additional data on human responses at an early stage of adaptation to weightlessness; to assess the effectiveness of countermeasures against adverse effects of weightlessness during and after flight. The orbital station was equipped with a set of countermeasuring devices: a trainer for physical exercises (a treadmill), gravity simulation suit for long wear, bicycle ergometer, anti-G suit to be worn immediately post-flight, drugs, etc. The system of medical control included daily recordings of electrocardiography and respiration and regular physical examinations using provocative tests (physical exercises of a known force, lower-body negative pressure). Specific biomedical investigations were performed before, during and after flight. As in previous flights, the atmosphere in the habitable modules was similar to that on the earth. Food supply met the requirements for basic nutrients and satisfied individual preferences of the crew members. In addition to the time required to fulfil the flight programme, the work-rest schedule allowed the cosmonauts 8 hours sleep, four meals, 2.5 hours physical training and personal time. The biomedical investigations carried out during and after flight furnished information towards a better understanding of human responses to the effects of space flight factors and the mechanisms underlying their development.

Adaptation, Physiological↗
PubMed1973

Some results of medical investigations performed during the flight of the research orbital station Salyut.

The paper presents the main results of physiological studies carried out during the flight of the Salyut station. Details of atmospheric composition, diet, provisions for personal hygiene, the on-board medical kit, prophylactic measures, work and rest schedule are given. Methods of investigation, particularly for studying the cardiovascular response, are described, including tests using the application of lower body negative pressure. The subjective and objective in-flight condition of the cosmonauts is dealt with in detail. An evaluation of the cardiovascular response is made, as compared with previous flights, both at rest and during tests. Results of clinical and biochemical studies of the blood, certain indices of visual perception and microbiological investigations are described. It is concluded that the observed physiological changes are reversible.

Adaptation, Physiological↗
PubMedDate not supplied

Summary of medical investigations in the U.S.S.R. manned space missions.

The results of biomedical investigations carried out in the U.S.S.R. manned space missions are discussed. Their basic result is well-documented evidence that man can perform space flights of long duration. The investigations have demonstrated no direct correlation between inflight or postflight physiological reactions of crewmembers and flight duration. In all likelihood, this can be attributed to the fact that special exercises done inflight efficiently prevented adverse effects of weightlessness. However, human reactions to weightlessness need further study. They include negative calcium balance and anemia as well as vestibulo-autonomic disorders shown by crewmembers at early stages of weightlessness. Attention should be given to psychological, social-psychological and ethical problems that may also limit further increase in flight duration.

Adaptation, Physiological↗