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Biomedical subjects

Kh Kh Iarullin

Publications and source records attributed to Kh Kh Iarullin.

At least 19 recordsLinked to original sources
PubMed1982

[Method of rheogram analysis based on separating out its arterial and venous components].

A method for rheogram analysis has been developed which enables one to separate the two components of a rheogram, i. e. the arterial and the venous ones. These two components reflect, respectively, the pulse fluctuations of the blood content of the arterial and the venous systems. Their separation is based on substantial differences between these fluctuations during a cardiac cycle. The method is used for synchronous recording of rheograms and their first derivatives, i. e. the differential rheograms. Data obtained with the use of the method make it possible to estimate the level of the blood content of the arterial network, the peripheral vascular resistance, and the conditions of the blood backflow from the venous network in a body region being examined.

Arteries↗
PubMed1977

[Analysis of the structure of the rheoencephalogram as a biosignal of pulsatile blood-filling].

In connection with an elaboration of a new method of analysing biosignals of pulse repletion, which used a systemic approach to the description of the cardiovascular system and a creation of a corresponding model of its work, the authors made a theoretical study of systematization of the manifold forms of rheograms in different conditions of the vascular tone. An analysis of the rheogram structures on the basis of the model of the cardiovascular system and a consideration of the rheograms as a summation of two components -- the arterial and venous -- permitted to eliminate some new indices of the tone state, elasticity and blood repletion of the arterial and venous bed, as well as the amount of peripheral vascular resistance.

Adult↗
PubMedDate not supplied

[Adaptation of the cardiovascular system to negative gravitation stresses during repeated antiorthostatic measures].

The cerebral, pulmonary, liver and peripheral circulation was studied simultaneously in 12 test subjects (aged 24--30) rheographically, photoplethysmographically and rheoplethysmographically; arterial pressure was measured by the Korotkoff method. The measurements were carried out during three antiorthostatic tests at --15degrees for 20 min or --30degrees for 20 min. It was shown that the cardiovascular system can adapt to repeated antiorthostatic exposures. The adaptation includes more significant decrease of the heart rate, increase in the systolic and pulse arterial pressure, fall of the diastolic arterial pressure, more marked reduction of antiorthostatically induced increase of blood filling and congestion of cerebral and pulmonary vessels, lesser decrease of their tone and blood redistribution into the vessels of the liver, upper and lower limbs. From the point of view of the adaptive effect repeated exposures to --15degrees are more effective.

Adaptation, Physiological↗
PubMedDate not supplied

[State of vascular regulation and regional hemodynamics in the crew of "Soiuz-12" and "Soiuz-13" spaceships before and after flight].

Postflight rheographic examinations carried out at rest and during postural tests showed noticeable changes in the vascular regulation and significant blood redistribution. On the recovery day there were no signs of the intracranical venous congestion to weightlessness. The tone of cerebral vessels, however, increased to prevent the development of cerebral venous congestions during the antiorthostatic test. This may be a result of weightlessness adaptation. These cerebral hemodynamic reactions were more pronounced in the crewmembers who made an 8-day flight than in those who made a two-day flight, i. e. in the cosmonauts who returned to Earth after weightlessness adaptation.

Arm↗
PubMedDate not supplied

[Characteristics of the functional state of the nervous system of middle-aged persons during anti-orthostatic hypokinesia].

The functional state of the nervous system and its autonomic compartment was investigated in 15 men, aged 40-52 years, during their 30-day exposure to head-down tilt (-8 degrees). Group 1 consisted of 9 subjects with early manifestations of cerebral atherosclerosis and Group 2 included 6 subjects with cerebral atherosclerosis and arterial hypertension. The control group incorporated 9 healthy volunteers, aged 25-39 years. During adaptation to head-down tilt, middle-aged and young subjects showed consistent changes in the nervous system. In response to perturbation effects, autonomic reactions were inert and autonomic support was excessive. However delayed onset of responses, duration and slow recovery of the parameters examined indicated that mechanisms of autonomic regulation were inadequate. These changes were most distinct in middle-aged subjects, particularly in Group 2 subjects: recovery of the functional state of the nervous system was completed by day 20 in middle-aged subjects and by day 9 in young subjects. The observations have demonstrated that the nervous system of most middle-aged subjects (taking into consideration age-related and atherosclerotic changes) has a sufficiently high level of functional capabilities during medium-duration head-down tilt studies.

Adult↗
PubMedDate not supplied

[Effect of exogenous cardiosynchronized contrapulsation on human regional and central hemodynamics].

Variations in regional and central hemodynamics of man under the influence of exogenous contrapulsation (ECP) were examined rheographically. In recumbent subjects, ECP increased cerebral pulse blood filling, particularly of the vertebrobasilar system. It appears that the significant increase of the tone of arterioles and veins may be important when it becomes necessary to correct cerebral circulation in the situations that may lead to brain ischemia. It has been found that in the orthostatic tilt test ECP can be an effective tool for enhancing brain and lung blood supply and increasing stroke volume, cardiac output and blood pressure. This may help maintain homeostasis and improve orthostatic tolerance. The observation that ECP may facilitate blood supply of the vitally important organs, specifically brain, enables us to recommend this procedure to be used at an early stage of readaptation after simulation or real space flights.

Adaptation, Physiological↗