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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 199 records · Page 11
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Medical Support and Findings of the Skylab Program

Specific equipment used in carrying out Skylab medical experiments is outlined and illustrated. Also included are reviews of the techniques, frequency, and protocols of the tests designed to study the long term effects of weightlessness on the human body. In-flight investigations were an evaluation of the cardiovascular system, a study of metabolic activity, investigations in the field of neurophysiology, the determination of changes in body fluids, a precise measurement of total body metabolism, and a study of crew performance by use of a time and motion experiment. Significant data obtained from in-flight and postflight tests are outlined.

Johnston, Richard S.↗
NASA NTRS1974

Research and operational efforts in support of Skylab experiment M093

The objectives of Skylab Experiment M093 were to measure electrocardiographic signals during spaceflight, to elucidate the electrophysiological basis for the changes observed, and to assess the effect of the change on the human cardiovascular system. Vectorcardiographic methods were used to quantitate changes, standardize data collection, and to facilitate reduction and statistical analysis of data. In this report the authors describe the M093 experiment design, the data transmission system, data reduction methods, and the analysis of data from the three Skylab missions. The report also includes clinical applications of the techniques developed for Skylab Experiment M093.

Smith, R. F.↗
NASA NTRS1976

Biomedical technical transfer. Applications of NASA science and technology

Lower body negative pressure testing in cardiac patients has been completed as well as the design and construction of a new leg negative unit for evaluating heart patients. This technology is based on NASA research, using vacuum chambers to stress the cardiovascular system during space flight. Additional laboratory tests of an intracranial pressure transducer, have been conducted. Three new biomedical problems to which NASA technology is applicable are also identified. These are: a communication device for the speech impaired, the NASA development liquid-cooled garment, and miniature force transducers for heart research.

Source record↗
NASA NTRS1977

Vectorcardiographic changes during extended space flight (M093): Observations at rest and during exercise

The objectives of Skylab Experiment M093 were to measure electrocardiographic signals during space flight, to elucidate the electrophysiological basis for the changes observed, and to assess the effect of the change on the human cardiovascular system. Vectorcardiographic methods were used to quantitate changes, standardize data collection, and to facilitate reduction and statistical analysis of data. Since the Skylab missions provided a unique opportunity to study the effects of prolonged weightlessness on human subjects, an effort was made to construct a data base that contained measurements taken with precision and in adequate number to enable conclusions to be made with a high degree of confidence. Standardized exercise loads were incorporated into the experiment protocol to increase the sensitivity of the electrocardiogram for effects of deconditioning and to detect susceptability for arrhythmias.

Smith, R. F.↗
NASA NTRS1975

The user's view of commercially available medical technology

The potential user of new medical equipment for imaging the cardiovascular system is often faced with the problem of deciding whether or not to accept a new piece of equipment or a new technological concept into the practice of cardiology. Considerations for acquiring new medical technology are discussed in some detail. Acquisition of new technology should depend on whether the equipment provides more and relevant clinical data, is for research or for limited use, is properly engineered for patient use, presents information in easily storable and retrievable form, is tested and validated clinically, is fabricated by a reliable manufacturer, is cost effective, and may be readily replaced by a new technology.

Harrison, D. C.↗
NASA NTRS1977

Mechanisms responsible for decreased glomerular filtration in hibernation and hypothermia

Measurements of blood pressure, heart rate, red blood cell and plasma volumes, and relative distribution of cardiac output were made on hibernating and hypothermic adult male and female golden hamsters weighing 120-140 g to study the mechanisms underlying the elimination or marked depression of renal function in hibernation and hypothermia. The results suggest that the elimination or marked depression in renal function reported in hibernation and hypothermia may partly be explained by alterations in cardiovascular system function. Renal perfusion pressure which decreases nearly 60% in both hibernation and hypothermia and a decrease in plasma volume of roughly 35% in the hypothermic animal might both be expected to markedly alter glomerular function.

Tempel, G. E.↗
NASA NTRS1977

Application and effectiveness of prophylactic devices in model experiments

Material is presented for evaluating the effectiveness of prophylactic devices intended for maintaining: a relatively high functional level of the cardiovascular system; the nerve and muscle apparatus; and the water and salt status. The effects of the following are analyzed: physical training, lower body negative pressure, regulation of water and salt consumption, pharmacological preparations, and a combination of these. The author points out the need for further research.

Kakurin, L. I.↗
NASA NTRS1978

Development opportunities in the space environment

Human physiological changes are outlined which occur in a space environment. It is shown that flexibility and adaptability are keys to maximizing neurological and body-functions for purposes of life support and health under reduced gravity conditions. Controlled manipulation of gravity in a space environment could reduce some aging problems by delaying the physical collapse of the skeleton, the cardiovascular system, and of tissues and organs.

Norton, R. D.↗
NASA NTRS1979

Joint Soviet-American experiment on hypokinesia: Experimental results

Comprehensive results are reported from the Soviet portion of a joint Soviet-American experiment involving hypokinesia. The main emphases are on chemical analyses of blood and urine, functional tests, and examination of the cardiovascular system by electrocardiography, echocardiography, and plethysmography.

Burovskiy, N. N.↗
NASA NTRS1979

Results of medical studies during long-term manned flights on the orbital Salyut-6 and Soyuz complex

Results of tests made on the crews of the Salyut-6 and Soyuz complex are presented. The basic results of studies made before, during and after 96-day and 140-day flights are presented in 5 sections: characteristics of flight conditions in the orbital complex; the cardiovascular system; the motor sphere and vestibular analyzer; biochemical, hematologic and immunologic studies; and recovery measures in the readaptation period.

Yegorov, A. D.↗
NASA NTRS1980

Blood circulation under conditions of weightlessness

Experimental materials and published data on the problem of blood circulation in man and animals under conditions of short and long term weightlessness are summarized. The data obtained allow the conclusion, that when humans spent 5 days in a weightless state their blood circulation was not essentially distributed. Some features of the functioning of the cardiovascular system are pointed out: delay of adaptation rate, increase in lability, etc. There is a discussion of the physiological mechanisms for the direct and indirect effect of weightlessness. The direct effect comprise the complex of reactions caused by the significant fall in hydrostatic pressure and the indirect embraces all the reactions arising in the organism resulting from disturbance of the systematic character of the analyzers that take part in the analysis of space realtions and the body's orientation in space.

Kastyan, I. I.↗
NASA NTRS1982

Effects of horizontal body casting on the baroreceptor reflex control of heart rate

The purpose of this study was to investigate the effects of long-term horizontal body position on baroreceptor reflex control of heart rate. Six male rhesus monkeys (6.2-9.4 kg) were given bolus injections of 4.0 microgram/kg, phenylephrine during each of the following conditions: awake, anesthetized (10 mg/kg ketamine HCl), and after beta-blockade (1 mg/kg propranolol HCl) before, 7, 14, and 28 days after being placed in a horizontal body cast. R-R interval vs. systolic arterial pressure was plotted, and the slope was determined by least-squares-fit linear regression. Baroreceptor slope was significantly reduced by 7 days of horizontal body position and remained attenuated throughout the 28-day restraint period both before and after beta-receptor blockade. These data are consistent with the thesis that prolonged exposure to a zero-gravity environment impairs autonomic reflex regulation of the cardiovascular system.

Billman, G. E.↗
NASA NTRS1982

Changes in blood volume and response to vaso-active drugs in horizontally casted primates

Experiments were performed on horizontally casted primates (male rhesus monkeys) in order to note changes in blood volume caused by horizontal restraint, to compare orthostatic tolerance before and after casting using the responses to upright tilting, to begin to uncover the cardiovascular and neural mechanisms involved in deconditioning, and to compare the data with that obtained from bed-rested human subjects and from humans exposed to weightlessness. Bolus injections of norepinephrine of 2.0 microgram/kg, phenylephrine of 4.0 microgram/kg, and nitroprusside of 2.0 microgram/kg were administered; and aortic pressure and heart rate were recorded during the injections. The results indicate that the horizontally casted primate is a valid animal model for studying the effects of simulated zero-G on the human cardiovascular system.

Dickey, D. T.↗
NASA NTRS1982

Aging and space travel

The matter of aging and its relation to space vehicle crewmembers undertaking prolonged space missions is addressed. The capabilities of the older space traveler to recover from bone demineralization and muscle atrophy are discussed. Certain advantages of the older person are noted, for example, a greater tolerance of monotony and repetitious activities. Additional parameters are delineated including the cardiovascular system, the reproductive system, ionizing radiation, performance, and group dynamics.

Mohler, S. R.↗
NASA NTRS1982

Status of joint US/USSR experiments planned for the Cosmos '83 biosatellite mission

The plans and status of the fourth joint US/USSR biosatellite experiment, scheduled to be conducted in the last half of 1983, are discussed. These experiments will be conducted on board an unmanned Soviet spacecraft and will involve two restrained Rhesus monkeys and 10 pregnant rats, as well as a variety of small plant and radiation biology experiments. Three of the joint studies will use the monkeys for studies of biorhythms, calcium homeostasis, and the cardiovascular system. The fourth experiment will study rodent embryogenesis and neonatal behavior and development following in utero exposure to spaceflight. Specialized sensors and battery powered hardware have been designed, fabricated, and qualified for flight.

Souza, K. A.↗
NASA NTRS1982

VO2 kinetics during submaximal exercise following simulated weightlessness

A study is presented of the effects of deconditioning following 7 days of continuous head-down (-6 degrees) bedrest on changes in steady-state VO2, O2, and recovery VO2 during the performance of constant-load exercises. The deconditioning effects of bedrest on the physical working capacity were manifested in the subjects by significant changes in VO2 kinetics following the 7 days of head-down bedrest. While the subjects demonstrated the ability to attain similar steady-state VO2, simulated weightlessness using head-down bedrest resulted in a reduction of total VO2 capacity and an increase in the O2 deficit and VO2 halftime during submaximal constant-load exercise. It is concluded that this change in VO2 kinetics was induced by reexposure of the cardiovascular system to the +1 Gz (upright) environment.

Convertino, V. A.↗