scholarly journals Measuring Entropy Change in a Human Physiological System

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Satish Boregowda ◽  
Rod Handy ◽  
Darrah Sleeth ◽  
Andrew Merryweather
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Skin Temperature ◽  
Cognitive Task ◽  
Entropy Change ◽  
Physiological Data ◽  
Multiple Time ◽  
Electrodermal Response ◽  
Physiological Measures ◽  
Human Engineering

The paper presents a novel approach involving the use of Maxwell relations to combine multiple physiological measures to provide a measure of entropy change. The physiological measures included blood pressure (BP), heart rate (HR), skin temperature (ST), electromyogram (EMG), and electrodermal response (EDR). The multiple time-series physiological data were collected from eight subjects in an experimental pilot study conducted at the Human Engineering Laboratory of NASA Langley Research Center. The methodology included data collection during a relaxation period of eighteen minutes followed by a sixty-minute cognitive task. Two types of entropy change were computed: (a) entropy change (ΔSBP) due to blood pressure, heart rate, and skin temperature and (b) entropy change (ΔSEMG) due to electromyogram, electrodermal response, and skin temperature. The results demonstrate that entropy change provides a valuable composite measure of individual physiological response to various stressors that could be valuable in the areas of medical research, diagnosis, and clinical practice.

The Effects of a Caffeine Placebo and Experimenter Expectation on Blood Pressure, Heart Rate, Well-Being, and Cognitive Performance

2001 ◽  
Vol 6 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Harald Walach ◽  
Stefan Schmidt ◽  
Yvonne-Michelle Bihr ◽  
Susanne Wiesch
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cognitive Task ◽  
Well Being ◽  
Control Group ◽  
Double Blind ◽  
Main Effect ◽  
The Difference ◽  
Being There ◽  
To Receive

We studied the effect of experimenter expectations and different instructions in a balanced placebo design. 157 subjects were randomized into a 2 × 4 factorial design. Two experimenters were led to expect placebos either to produce physiological effects or not (pro- vs. antiplacebo). All subjects except a control group received a caffeine placebo. They were either made to expect coffee, no coffee, or were in a double-blind condition. Dependent measures were blood pressure, heart rate, well-being, and a cognitive task. There was one main effect on the instruction factor (p = 0.03) with the group “told no caffeine” reporting significantly better well-being. There was one main effect on the experimenter factor with subjects instructed by experimenter “proplacebo” having higher systolic blood pressure (p = 0.008). There was one interaction with subjects instructed by experimenter “proplacebo” to receive coffee doing worse in the cognitive task than the rest. Subjects instructed by experimenter “antiplacebo” were significantly less likely to believe the experimental instruction, and that mostly if they had been instructed to receive coffee. Contrary to the literature we could not show an effect of instruction, but there was an effect of experimenters. It is likely, however, that these experimenter effects were not due to experimental manipulations, but to the difference in personalities.

Cardiovascular responses to head-stand posture

1963 ◽  
Vol 18 (5) ◽  
pp. 987-990 ◽  
Author(s):  
Shanker Rao
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
High Pressure ◽  
Blood Flow ◽  
Arterial Pressure ◽  
Skin Temperature ◽  
Cardiovascular Responses ◽  
Posterior Tibial Artery ◽  
Nervous Control ◽  
Posterior Tibial

Reports of cardiovascular responses to head-stand posture are lacking in literature. The results of the various responses, respectively, to the supine, erect, and head-stand posture, are as follows: heart rate/min 67, 84, and 69; brachial arterial pressure mm Hg 92, 90, and 108; posterior tibial arterial pressure mm Hg 98, 196, and 10; finger blood flow ml/100 ml min 4.5, 4.4, and 5.2; toe blood flow ml/100 ml min 7.1, 8.1, and 3.4; forehead skin temperature C 34.4, 34.0 and 34.3; dorsum foot skin temperature C 28.6, 28.2, and 28.2. It is inferred that the high-pressure-capacity vessels between the heart level and posterior tibial artery have little nervous control. The high-pressure baroreceptors take active part in postural adjustments of circulation. The blood pressure equating mechanism is not as efficient when vital tissues are pooled with blood as when blood supply to them is reduced. man; heart rate; blood flow; skin temperature Submitted on January 3, 1963

Effects of caffeine on blood pressure, heart rate, and forearm blood flow during dynamic leg exercise

1998 ◽  
Vol 85 (1) ◽  
pp. 154-159 ◽  
Author(s):  
Jason W. Daniels ◽  
Paul A. Molé ◽  
James D. Shaffrath ◽  
Charles L. Stebbins
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Systolic Blood Pressure ◽  
Skin Temperature ◽  
Rectal Temperature ◽  
Forearm Blood Flow ◽  
Dynamic Exercise ◽  
Ang Ii ◽  
Leg Exercise

This study examined the acute effects of caffeine on the cardiovascular system during dynamic leg exercise. Ten trained, caffeine-naive cyclists (7 women and 3 men) were studied at rest and during bicycle ergometry before and after the ingestion of 6 mg/kg caffeine or 6 mg/kg fructose (placebo) with 250 ml of water. After consumption of caffeine or placebo, subjects either rested for 100 min (rest protocol) or rested for 45 min followed by 55 min of cycle ergometry at 65% of maximal oxygen consumption (exercise protocol). Measurement of mean arterial pressure (MAP), forearm blood flow (FBF), heart rate, skin temperature, and rectal temperature and calculation of forearm vascular conductance (FVC) were made at baseline and at 20-min intervals. Plasma ANG II was measured at baseline and at 60 min postingestion in the two exercise protocols. Before exercise, caffeine increased both systolic blood pressure (17%) and MAP (11%) without affecting FBF or FVC. During dynamic exercise, caffeine attenuated the increase in FBF (53%) and FVC (50%) and accentuated exercise-induced increases in ANG II (44%). Systolic blood pressure and MAP were also higher during exercise plus caffeine; however, these increases were secondary to the effects of caffeine on resting blood pressure. No significant differences were observed in heart rate, skin temperature, or rectal temperature. These findings indicate that caffeine can alter the cardiovascular response to dynamic exercise in a manner that may modify regional blood flow and conductance.

An educational tool for understanding the cardiovascular changes associated with diabetes.

1995 ◽  
Vol 269 (6) ◽  
pp. S4 ◽  
Author(s):  
H L Collins ◽  
S E DiCarlo
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Plasma Insulin ◽  
Cardiovascular Responses ◽  
High Plasma ◽  
Physiological Data ◽  
Educational Tool ◽  
Problem Solving Skills ◽  
Laboratory Exercise ◽  
High Plasma Glucose

Diabetes, a syndrome characterized by high plasma glucose and low plasma insulin concentrations, is associated with somatic and autonomic neuropadiabetes as well as cardiac and vascular disorders. These consequences of diabetes significantly affect the organism's ability to maintain homeostasis. To understand the changes associated with diabetes, we developed a laboratory exercise that compares and contrasts the cardiovascular responses to exercise in an individual with diabetes and in an individual without diabetes. This exercise provides a unique opportunity to analyze, integrate, and interpret the changes associated with diabetes, since more is learned about how a system operated when the system is forced to perform than when it is idle. In this laboratory, anatomical and physiological data concerning diabetes are provided. Subsequently, a figure that illustrates the response of a specific cardiovascular variable during exercise (e.g., heart rate, cardiac output, blood pressure) is presented. Students are challenged to analyze and assimilate information from figures, answer questions, make calculations, fill in tables, and plot graphs. The laboratory does not require equipment or software, only rulers and pencils. The answers to the questions and tables are provided in the APPENDIX. Students obtain experience in evaluating and understanding diabetes as well as applying basic cardiovascular concepts. The emphasis is on the application of basic cardiovascular principles, interpretation of pictorial or tabular material, and problem-solving skills.

Psychophysiological Changes following Auditory Subliminal Suggestions for Activation and Deactivation

1983 ◽  
Vol 56 (3) ◽  
pp. 759-766 ◽  
Author(s):  
François Borgeat ◽  
Jean Goulet
Keyword(s):  
Heart Rate ◽  
Multivariate Analysis ◽  
White Noise ◽  
Skin Temperature ◽  
Analysis Of Variance ◽  
Skin Conductance ◽  
Physiological Measures ◽  
Psychophysiological Responses ◽  
Skin Conductance Levels ◽  
Control Situation

This study was to measure eventual psychophysiological changes resulting from auditory subliminal activation or deactivation suggestions. 18 subjects were alternately exposed to a control situation and to 25-dB activating and deactivating suggestions masked by a 40-dB white noise. Physiological measures (EMG, heart rate, skin-conductance levels and responses, and skin temperature) were recorded while subjects listened passively to the suggestions, during a stressing task that followed and after that task. Multivariate analysis of variance showed a significant effect of the activation subliminal suggestions during and following the stressing task. This result is discussed as indicating effects of consciously unrecognized perceptions on psychophysiological responses.

The Diurnal Pattern of Salivary Flow in Normal and Depressed Patients

1965 ◽  
Vol 111 (473) ◽  
pp. 334-338 ◽  
Author(s):  
G. Palmai ◽  
B. Blackwell
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Mental Illness ◽  
Skin Temperature ◽  
Prognostic Value ◽  
Autonomic Function ◽  
Salivary Flow ◽  
Salivary Secretion ◽  
Diurnal Pattern ◽  
Theoretical Assumptions

Attempts to correlate diagnosis or prognosis in depression with metabolic or autonomic parameters have been largely unsuccessful. Although electrolyte fluctuations coincide with some cyclical psychoses (Rey, 1957) these may be causal or incidental and their endocrine origin is undefined. Similar difficulties are inherent in studies of autonomic function (Martin, 1960) which have included observations on skin temperature and resistance (G.S.R.), heart rate, pupil reactions and muscle potentials. Much interest has focused on the blood pressure, and the Funkenstein test has emphasized the difficulties of this research. After widespread study and application, its prognostic value, the reliability of its measurements and the basic theoretical assumptions are now largely discredited (Rose, 1962). In the search for reliable objective criteria to evaluate or explain the phenomena of mental illness salivary secretion may prove of considerable value.

scholarly journals TWO PATTERNS ОF CT-BRAIN PERFUSION AND DC-POTENTIALS ОF THE BRAIN EVOKED COGNITIVE TASK IN DISCIRCULATORY ENCEPHALOPATHY PATIENTS

2012 ◽  
Vol 67 (10) ◽  
pp. 38-43
Author(s):  
V. F. Fokin ◽  
N. V. Ponomareva ◽  
M. V. Krotenkova ◽  
R. N. Konovalov ◽  
M. M. Tanashyan ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Verbal Fluency ◽  
Cerebral Perfusion ◽  
Cognitive Task ◽  
Brain Perfusion ◽  
Verbal Fluency Test ◽  
The Brain ◽  
Fluency Test ◽  
Dc Potentials

In patients with discirculatory encephalopathy the influence of verbal fluency test on the characteristics of cerebral perfusion, DC-potentials of the brain, as well as on blood pressure and heart rate was investigated. Two patterns of responses to the verbal fluency test were observed. The first one is the process of generalized activation, manifested by the reduction of the TTP (time to peak) parameters of brain perfusion, the rise of the DC-potentials in all areas of brain and the modulation of blood pressure and heart rate. The second process, directly connected with cognitive processing, was manifested by the shifts of local characteristics of brain perfusion and DC-potentials in the frontal, temporal and central cortex, especially in the left hemisphere. Correlations were found between the characteristics of cerebral perfusion and DC-potentials on the one hand and the number of words during the verbal fluency test performance on the other hand. 

Influence of tobacco smoking on the origin of thromboangeitis obliterans

1934 ◽  
Vol 30 (11-12) ◽  
pp. 1208-1208
Author(s):  
W. G. Maddock ◽  
F. А. Сoller
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Skin Temperature ◽  
Tobacco Smoking ◽  
Peripheral Vasoconstriction

The authors note that smoking tobacco causes an increase in blood pressure and heart rate and a decrease in skin temperature in the fingers and toes due to increased peripheral vasoconstriction. The authors confirm these findings with experimental observations.

An educational tool for understanding the cardiopulmonary changes associated with aging.

1994 ◽  
Vol 267 (6) ◽  
pp. S17 ◽  
Author(s):  
M P Chandler ◽  
S E DiCarlo
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Educational Process ◽  
Physiological Data ◽  
Educational Tool ◽  
Evaluation Instrument ◽  
Instructional Tool ◽  
Problem Solving Skills ◽  
Laboratory Exercise ◽  
Questions And Answers

Normal aging is associated with cardiac, vascular, and pulmonary adaptations that significantly affect the individual's ability to maintain homeostasis. To understand the changes associated with aging, we developed a laboratory exercise that compares and contrasts the cardiopulmonary responses to exercise in a young and an older individual. We also developed this interactive tool because it is our experience that learning is better facilitated when students are encouraged, and required, to become an active and integral part of the educational process. This exercise provides a unique opportunity to analyze, integrate, and interpret the changes associated with aging because more is learned about how a system operates when it is forced to perform than when it is idle. In this laboratory exercise, basic anatomical and physiological data about aging are provided. Subsequently, figures are presented that illustrate the responses of specific cardiopulmonary variables during exercise (e.g., heart rate, cardiac output, blood pressure), and the students are challenged to analyze and assimilate information from the figures, answer questions, make calculations, and plot graphs. The laboratory does not require equipment or software, only rules and pencils. Questions, and answers to them, are provided in the appendix. The emphasis is on the application of basic science principles, interpretation of pictorial or tabular material, and problem solving skills. In addition, an evaluation instrument was developed to assess the effectiveness of this instructional tool in an academic setting. Specifically, the evaluation instrument addressed four major components, including aims and objectives, content of materials, components and organization, and summary and recommendations.

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