From Big Medical Encyclopedia

CENTRIFUGES IN AIR AND SPACE MEDICINE — the research and test stands intended for studying of influence on an organism of various accelerations (overloads), for a training of aircrew, Krom should work in the conditions of overloads, medical examination of aircrew and the scientific research conducted for the purpose of medical support and safety of flights.

Centrifuges give the chance to model various profiles of overloads with the broad range, with to-rymi the aircrew on modern and perspective aircraft meets or can meet. The possibilities of use of the principle of centrifuges in space aircraft for creation of artificial gravity and the prevention of adverse action on an organism of zero gravity are considered.

According to above-mentioned tasks centrifuges, various on a design, technical characteristics, parameters of the created overloads

(fig.) are used.

At trainings of aircrew trained feel the feelings connected with the overloads close to those, to-rye them it is necessary to test in flight; study the correct distribution of muscular efforts (in particular, muscles of a prelum abdominale) that helps to transfer easier overloads and to successfully carry out professional tasks in these conditions. By means of centrifuges doctors study impact on the person of nek-ry difficult types of accelerations, in particular Coriolis's accelerations (see Coriolis acceleration). For this purpose along with rotation of a cabin around an axis of the centrifuge inclinations and turns of the head of the examinee are carried out (see. A vestibular training) or rotation of a cabin around the axes.

At medical and flight examination (see. An air medicine, the Medical and flight commission) on tsentri-

Fig. Centrifuges for a training of pilots and astronauts: and — with the closed cabin;

— with an open cabin.

to the fugue define individual sensitivity and stability inspected to overloads that has essential value at selection of candidates for training in flight business and at examination of suitability to continuation of flight work.

By means of the centrifuge in pilot studies on animals and with participation of testers features of impact on an organism of the overloads having various characteristics are studied (the direction concerning axes of a body, duration of action, the steepness of increase and reduction of size of an overload); means and methods of protection of an organism against overloads (form of a chair of the pilot and astronaut, tilt angle of its back, system of fixing of a body of the person, anti-overload suits, the oxygen and respiratory equipment etc.) are developed and tested; optimum systems of display of information and control of the aircraft at influence of overloads are tested, rational forms of a training and training of aircrew, including nonspecific methods of increase in stability of an organism. Along with overloads and definition of efficiency of activity of the pilot and astronaut other factors of flight, napr, various gas composition and pressure of inhaled air, vibration, etc. are studied (see Medicine space).

In an experiment on animals are investigated fiziol., biochemical and pestilence foul. the changes occurring in an organism at action intensive, and also repeatedly repeating and hron. overloads. For studying biol. roles of gravitation and biol. effects of hyper gravitation experiments on the small animals (in particular, on rats) who are grown up in the conditions of continuous influence of overloads on the centrifuge are made, and onboard artificial Earth satellites experiments on the laboratory animals placed on the small centrifuges creating artificial gravitation of various degree are made.

The centripetal radial acceleration (see) created at rotation of centrifuges imitates acceleration of the aircraft. However existence of angular speed and angular acceleration (at insufficiently big radius of gyration) can complicate a little a picture, in particular owing to influence on a vestibular mechanism. Therefore centrifuges for pilots and astronauts usually have the radius of gyration of 7 — 10 m and more, and for creation of artificial gravitation in space radius of gyration, on a nek-eye to data, there have to be not less than 30 m. To dogs and small laboratory animals use considerably centrifuges, smaller by the size.

Bibliography: Isakov P. K. idr. Theory and practice of an air medicine, M., 1975; Fundamentals of bioastronautics and medicine, under the editorship of O. G. Gazenko and M. Calvin, t. 2, book 1, M., 1975; With e r e-

e in A. A. Physiological mechanisms of action of accelerations, JT., 1967. H. M. Rudny.