Evaluation of flight foods under hypokinetic conditions, part 2, chapters 4 and 5
Effects of weightlessness on body temperature and heart rate determined by 56 day bed rest study
Cronin, S. E.↗
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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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Development and evaluation of an impedance cardiographic system to measure cardiac output and other cardiac parameters Final progress report 1 Jul. 1969 - 31 Dec. 1970
Performance of impedance cardiograph for measuring heart rate and body fluids
From, A. H. L.↗
Long-duration exercise at moderate work loads
Metabolic effects of long duration exercise at moderate work loads including tables of heart rate, rectal temperature, minute volume, water balance, and respiratory quotient
Camacho, A.↗
Lower body negative pressure as an assay technique for orthostatic tolerance. III - A comparison of the individual response to incremental leg negative pressure vs incremental lower body negative pressure
Human orthostatic tolerance measurement via leg and lower body negative pressure, discussing heart rate and stroke volume variations
Hoffler, G. W.↗
Cardiovascular observations of the Macaca nemestrina monkey in Biosatellite III
In-flight monkey cardiovascular observations, discussing central venous pressure, urine volume, electrolyte imbalances and heart rate
Meehan, J. P.↗
Dynamic respiratory and circulatory responses to hypoxia in the anesthetized dog
Dynamic respiratory and circulatory responses to hypoxia in anesthetized dogs, recording oxygen partial pressures, heart rate, blood pressure, blood flows, respiratory rate, etc
Carrell, D. E.↗
Physiological responses to a rotating environment
Human physiological responses to rotating environment, evaluating heart rates, blood pressure, pulmonary functions, visual observations and vital capacities
Green, J. A.↗
Action of pharmacologic agents in experimental cardiac tamponade
Isoproterenol, atrial pacing, ouabain and methoxamine effects on dogs during experimental cardiac tamponade, observing arterial pressure, cardiac output and heart rate changes
Finegan, R. E.↗
Electronic circuit detects left ventricular ejection events in cardiovascular system
Electronic circuit processes arterial blood pressure waveform to produce discrete signals that coincide with beginning and end of left ventricular ejection. Output signals provide timing signals for computers that monitor cardiovascular systems. Circuit operates reliably for heart rates between 50 and 200 beats per minute.
Gebben, V. D.↗
Metabolic, respiratory, and cardiological measurements during exercise and rest
Low concentration effects of CO2 on metabolic respiration and circulation were measured during work and at rest. The relationship between heart rate and metabolic rate is examined, as well as calibration procedures, and rate measurement during submaximal and standard exercise tests. Alterations in acid base and electrolytes were found during exhaustive exercise, including changes in ECG and metabolic alkalosis effects.
Source record↗
Conversion of cardiac performance data in analog form for digital computer entry
A system is presented which will reduce analog cardiac performance data and convert the results to digital form for direct entry into a commercial time-shared computer. Circuits are discussed which perform the measurement and digital conversion of instantaneous systolic and diastolic parameters from the analog blood pressure waveform. Digital averaging over a selected number of heart cycles is performed on these measurements, as well as those of flow and heart rate. The determination of average cardiac output and peripheral resistance, including trends, is the end result after processing by digital computer.
Miller, R. L.↗
Design of a specialized computer for on-line monitoring of cardiac stroke volume
The design of a specialized analog computer for on-line determination of cardiac stroke volume by means of a modified version of the pressure pulse contour method is presented. The design consists of an analog circuit for computation and a timing circuit for detecting necessary events on the pressure waveform. Readouts of arterial pressures, systolic duration, heart rate, percent change in stroke volume, and percent change in cardiac output are provided for monitoring cardiac patients. Laboratory results showed that computational accuracy was within 3 percent, while animal experiments verified the operational capability of the computer. Patient safety considerations are also discussed.
Webb, J. A., Jr.↗
The study of human venous system dynamics using hybrid computer modeling
A computer-based model of the cardiovascular system was created emphasizing effects on the systemic venous system. Certain physiological aspects were emphasized: effects of heart rate, tilting, changes in respiration, and leg muscular contractions. The results from the model showed close correlation with findings previously reported in the literature.
Snyder, M. F.↗
Importance of the splanchnic vascular bed in human blood pressure regulation.
Three-part experiment in which five subjects were exposed to lower body negative pressure (LBNP) at -50 mm Hg below the iliac crests. Duration of LBNP to earliest vagal symptoms was 7 to 21 min; all data are expressed as changes from control period to the last measurements before these symptoms. In part I, forearm blood flow (by Whitney gauge) fell 45% during LBNP. In part II, splanchnic blood flow (from arterial clearance hepatic extraction of indocyanine green) fell 32% and splanchnic vascular resistance rose 30%. In part III, cardiac output fell 28%, stroke volume 51%, and central blood volume 21%. Total peripheral resistance and heart rate rose 19% and 52%. Of the reduction in total vascular conductance, decreased splanchnic conductance accounted for approximately 33%; skin plus muscle conductance decreased similarly.
Rowell, L. B.↗
Cardiac beta-adrenergic receptors and coronary hemodynamics in the conscious dog during hypoxic hypoxia.
The mechanisms by which acute hypoxia (10% and 5% oxygen) mediates changes in coronary blood flow and cardiac function were investigated in the conscious dog. When the dogs breathed hypoxic gas mixtures through a tracheostomy, both arterial and coronary sinus oxygen tensions were significantly decreased. With 5% oxygen, there were significant increases in heart rate (25%), maximum left ventricular dP/dt (39%), left circumflex coronary artery blood flow (163%), and left ventricular oxygen consumption (52%), which were attenuated by beta-adrenergic blockage with propranolol. When electrical pacing was used to keep the ventricular rate constant during hypoxia, there was no significant difference in coronary blood flow before and after beta blockade. Beta-adrenergic receptor activity in the myocardium participates in the integrated response to hypoxia although it may not cause active vasodilation of the coronary vessels.
Erickson, H. H.↗
Circadian rhythms of visual accommodation responses and physiological correlations.
Use of a recently developed servocontrolled infrared optometer to continuously record the state of monocular focus while subjects viewed a visual target for which the stimulus to focus was systematically varied. Calculated parameters form recorded data - e.g., speeds of accommodation to approaching and receding targets, magnitude of accommodation to step changes in target distance, and amplitude and phase lag of response to sinusoidally varying stimuli were submitted to periodicity analyses. Ear canal temperature (ECT) and heart rate (HR) rhythms were also recorded for physiological correlation with accommodation rhythms. HR demonstrated a 24-hr rhythm, but ECT data did not.
Murphy, M. R.↗
Cardiovascular responses to glucagon - Physiologic measurement by external recordings.
Assessment by noninvasive polygraphic techniques of the cardiovascular responses of normal subjects to intravenous injections of glucagon and glucagon diluent. A blinding procedure which eliminated observer bias was used during the reading of tracings. Analysis of group results showed that glucagon provoked uniformly significant changes, including increase in heart rate, blood pressure, pressure-rate product, and ejection time index, and decrease in prejection period, mechanical and electromechanical systole, left ventricular ejection time, and the ratio PEP/LVET. The principal results correlated well with those of previous studies of the hemodynamic effects of glucagon.
Byrne, M. J.↗
Effects of stress upon psychophysiological responses and performance following sleep deprivation
The usefulness of psychological and physiological variables in predicting performance under stress of 48 hours of sleep deprivation was investigated. Performance tests, with subjects of different ego strength personalities, in concept acquisition, reading comprehension, word association, word memory, and anagrams were conducted, and physiological measurements of (1) the phasic and tonic electrodermal, (2) galvanic skin response, (3) thermal skin resistance, (4) heart rate, (5) respiration, and (6) plethysmographic finger pulse volumn were recorded. It was found that the changes in the pattern of performance were the result of testing subjects at times when they would normally be sleeping, and that sleep deprivation longer than 48 hours must be maintained to produce changes in simple or well learned tasks.
Roessler, R.↗