Search results for "HEART RATE"
showing 10 items of 887 documents
A study on the effect of contact pressure during physical activity on photoplethysmographic heart rate measurements
2020
Heart rate (HR) as an important physiological indicator could properly describe global subject&rsquo
Human Heart-Related Indexes Behavior Study for Aircraft Pilots Allowable Workload Level Assessment
2022
This study aimed to evaluate workload by detecting Heart Rate Variability (HRV) indexes in a sample of 34 pilots (with a mean age of 33 years) while performing simulated flight exercises. A one-way ANOVA with repeated measures was performed to assess the changes of the physiological measures in five standard maneuvers associated with different workload levels. The results show that all the indexes, but the Low Frequency to High Frequency ratio index (LF/HF), have a well-defined trend between the baseline and the en-route phase and with the three phases takeoff, steady turn, and landing. This study, as main findings, provides evidence of a differentiation among low, medium, and high workload…
Extending the spectral decomposition of Granger causality to include instantaneous influences: application to the control mechanisms of heart rate va…
2021
Assessing Granger causality (GC) intended as the influence, in terms of reduction of variance of surprise, that a driver variable exerts on a given target, requires a suitable treatment of ‘instantaneous’ effects, i.e. influences due to interactions whose time scale is much faster than the time resolution of the measurements, due to unobserved confounders or insufficient sampling rate that cannot be increased because the mechanism of generation of the variable is inherently slow (e.g. the heartbeat). We exploit a recently proposed framework for the estimation of causal influences in the spectral domain and include instantaneous interactions in the modelling, thus obtaining (i) a novel index…
Anticipatory autonomic response to a public speaking task in women
2002
The aim of this research was to study anticipatory autonomic responses their relationship to trait anxiety. Twenty-three women prepared an evaluated speech (S-condition) and 22 women an evaluated essay (W-condition). Heart rate (HR), finger pulse volume (FPV) and skin conductance were recorded before, during and after preparation of the task and during task performance; state-anxiety was evaluated before and after the task. In the total sample, state-anxiety was higher in the S- than in W-condition and this anxiety increase was accompanied by FPV reductions. However, when the sample was split according to trait anxiety scores, HR during preparation and increases of state-anxiety were greate…
Coffee increases state anxiety in males but not in females.
2003
Coffee, reproducing the conditions under which caffeine is normally ingested, containing 3, 75, 150 or 300 mg of caffeine was given to healthy male and female volunteers. 25-30 min after drinking the beverage, they completed the Spanish version of the state-trait anxiety inventory (STAI). The beverage increased state anxiety, in a dose-dependent manner, in males but not in females. This could be due to a lesser sensitivity of females to coffee.
Strain of employees in the machine industry in Finland.
1978
In order to investigate the strain of workers in different occupations of the Finnish machine industry, energy expenditure and heart rate of 190 men and 47 women employees were measured during their normal course of work. Work was most strenuous in occupations in the early stages of production and in unskilled jobs. The relative strain of semi-skilled workers was highest in the oldest age groups, over 45 years. It is concluded that when systems for grading the strain of industrial work are constructed, the long-term effects of work and workers' characteristics such as age, sex, weight and physical fitness should be taken into consideration.
Physical Activity : Absolute Intensity vs. Relative-to-Fitness-Level Volumes
2017
Purpose: This study aimed to investigate in a real-life setting how moderate- and vigorous-intensity physical activity (PA) volumes differ according to absolute intensity recommendation and relative to individual fitness level by sex, age, and body mass index. Methods: A total of 23,224 Finnish employees (10,201 men and 13,023 women; ages 18–65 yr; body mass index = 18.5–40.0 kg·m−2) participated in heart rate recording for 2+ d. We used heart rate and its variability, respiration rate, and on/off response information from R-R interval data calibrated by participant characteristics to objectively determine daily PA volume, as follows: daily minutes of absolute moderate (3–<6 METs) and vigor…
Identifying poor cardiorespiratory fitness in overweight and obese children and adolescents by using heart rate variability analysis under resting co…
2020
Background: Childhood obesity, including overweight, continues increasing worldwide affecting health expectancy, quality of life and healthcare expenditure. These subjects have higher probability of suffering or developing cardio metabolic risk factors. Recent studies have revealed cardiorespiratory fitness (CRF) as a valuable clinical parameter to identify these subjects and have even suggested cut-off values. However, evaluating CRF in overweight and obese youth can be difficult to implement, unfriendly and expensive. Objective: Develop a screening tool to identify high-risk subjects in a representative population of those attending overweight/obesity assessment programmes without prior i…
Heart Rate Variability Recordings are a Valid Non- Invasive Tool for Evaluating Soldiers’ Stress
2013
Heart Rate Variability Recordings are a Valid Non- Invasive Tool for Evaluating Soldiers’ Stress The purpose of the present study was to investigate physiological responses and to evaluate heart rate variability as a non-invasive stress indicator during a 72-hour military field training (MFT). Ten healthy male soldiers (age 20 ± 1 yr.) participated in MFT. They slept approximately 2 h/day and ate only army field rations. During MFT, the soldiers’ mean (±SD) energy expenditure was 4646 ± 674, energy intake 2200 ± 326, and energy deficit (ED) 2405 ± 890 kcal⋅day-1.Throughout the entire training period, serum total testosterone (TES) reduced from 19.0 ± 3.0 to 12.6 ± 6.2 nmol⋅l-1 (p<0.001)
Granger causality analysis of sleep brain-heart interactions
2014
We studied the networks of Granger causality (GC) between the time series of cardiac vagal autonomic activity and brain wave activities, measured respectively as the normalized high frequency (HF) component of heart rate variability and EEG power in the δ, θ, α, Ï, β bands, computed in 10 healthy subjects during sleep. GC analysis was performed by vector autoregressive modeling, and significance of each link in the network was assessed using F-statistics. The whole-night analysis revealed the existence of a fully connected network of brain-heart and brain-brain interactions, with the à EEG power acting as a hub which conveys the largest number of GC links between the heart and brain n…