scholarly journals Cardiovascular Biomarkers’ Inherent Timescales in Mental Workload Assessment During Simulated Air Traffic Control Tasks

Author(s):  
Thea Radüntz ◽  
Thorsten Mühlhausen ◽  
Marion Freyer ◽  
Norbert Fürstenau ◽  
Beate Meffert

Abstract One central topic in ergonomics and human-factors research is the assessment of mental workload. Heart rate and heart rate variability are common for registering mental workload. However, a major problem of workload assessment is the dissociation among different workload measures. One potential reason could be the disregard of their inherent timescales and the interrelation between participants’ individual differences and timescales. The aim of our study was to determine if different cardiovascular biomarkers exhibit different timescales. We focused on air traffic controller and investigated biomarkers’ ability to distinguish between conditions with different load levels connected to prior work experience and different time slots. During an interactive real-time simulation, we varied the load situations with two independent variables: the traffic volume and the occurrence of a priority-flight request. Dependent variables for registering mental workload were the heart rate and heart rate variability from two time slots. Our results show that all cardiovascular biomarkers were sensitive to workload differences with different inherent timescales. The heart rate responded sooner than the heart rate variability features from the frequency domain and it was most indicative during the time slot immediately after the priority-flight request. The heart rate variability parameters from the frequency domain responded with latency and were most indicative during the subsequent time slot. Furthermore, by consideration of biomarkers’ inherent timescales, we were able to assess a significant effect of work experience on heart rate and mid/high frequency-band ratio of the heart rate variability. Results indicated that different cardiovascular biomarkers reveal different inherent timescales.

1994 ◽  
Vol 28 (8) ◽  
pp. 1273-1276 ◽  
Author(s):  
J. O Valkama ◽  
H. V Huikuri ◽  
K E J. Airaksinen ◽  
M. L Linnaluoto ◽  
J. T Takkunen

Author(s):  
Alexandr E. Nosov ◽  
Nina V. Zaitseva ◽  
Vitalii G. Kostarev ◽  
Julia A. Ivashova ◽  
Maksim A. Savinkov ◽  
...  

Introduction. Currently, the violation of heart rate variability as one of the main pathogenetic mechanisms of the damaging effect of pollutants, associated effects on the cardiovascular system. The study aims to explore the dynamics of the influence of the autonomic nervous system (ANS) on heart rate variability (HRV) in workers of a potassium ore processing enterprise exposed to industrial pollutants (fine fractions of potassium chloride dust, formaldehyde, hexane, heptane) with an assessment of changes in dependence from work experience, establishment of cause-and-effect relationships of violations of heart rate variability with exposure to chemical compounds. Materials and methods. The object of the study was 140 employees of a potash ore processing enterprise, assigned to the observation group, and 76 employees of the administrative and technical apparatus, who made up the comparison group. Samples were taken from the air of the working medium for the content of saturated hydrocarbons (hexane, heptane), the vapors of formhehyde were considered, and the presence of fine particles PM2.5 and PM10 was established. Investigation of biological media (blood, urine) of workers at the enterprise determination of formaldehyde in blood, hexane and heptane in urine. Evaluation of heart rate variability was carried out on a computer electrocardiograph "Poli-Spectr-8/EX" using a cardiorhythmographic program using the method of time analysis, variation pulsometry and spectral analysis. Results. The concentration of fine particles in the air at the workplaces of the observation group was 12-111 times higher for PM2.5, and 5.6-74.6 times higher for PM10 than for the work places of the comparison group. The concentration of formaldehyde, hexane and heptane in the air did not exceed hygienic standards. In the observation group relative to the comparison group, formaldehyde blood was 1.5 times (p<0.001), in the urine of hexane - 1.2 times (p=0.011), heptane - 1.3 times (p=0.046). It was found that with an experience of up to 10 years, formaldehyde in the blood of workers in the observation group was 1.4 times higher than that in the comparison group (p=0.011), with an experience of more than 10 years - 1.7 times (p=0.005). In the urine of workers in the observation group with work experience of up to 10 years, an excess of 1.3 (p=0.026) relative to the comparison group of hexane was found. HRV data analysis. With damage to the length of service in the observation group, there was a significant decrease in the temporal analysis indicators (SDNN, ms, RMSSD, ms, pNN50, %, CV, %), while in the comparison group, only the CV, % decrease was statistically significant; the values of IN conventional units, AMo, % significantly increased (p=0.03 and p=0.003, respectively). A statistically significant relationship was established between the likelihood of an increase depending on the content of heptane in urine (b0=0.22; b1=10.6; F=21.5; R2=0.09; p=0.0001) and formaldehyde in the blood (b0=0.02; b1=6.55; F=69.6; R2=0.25; p=0.0001) in the surveyed workers. Conclusions. Activation of central ergotropic and humoral-metabolic mechanisms, a tendency towards a decrease in parasympathetic influences. The method of logistic regression analysis established a statistically significant relationship between the probability of an increase in the stress index depending on the heptane content in the blood of the surveyed suppliers.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Meenakshi Chaswal ◽  
Raj Kapoor ◽  
Achla Batra ◽  
Savita Verma ◽  
Bhupendra S. Yadav

Alterations in the autonomic cardiovascular control have been implicated to play an important etiologic role in preeclampsia. The present study was designed to evaluate autonomic functions in preeclamptic pregnant women and compare the values with normotensive pregnant and healthy nonpregnant controls. Assessment of autonomic functions was done by cardiovascular reflex tests and by analysis of heart rate variability (HRV). Cardiovascular reflex tests included deep breathing test (DBT) and lying to standing test (LST). HRV was analyzed in both time and frequency domain for quantifying the tone of autonomic nervous system to the heart. The time domain measures included standard deviation of normal R-R intervals (SDNN) and square root of mean squared differences of successive R-R intervals (RMSSD). In the frequency domain we measured total power (TP), high frequency (HF) power, low frequency (LF) power, and LF/HF ratio. Cardiovascular reflex tests showed a significant parasympathetic deficit in preeclamptic women. Among parameters of HRV, preeclamptic group had lower values of SDNN, RMSSD, TP, HF, and LF (ms2) and higher value of LF in normalised units along with high LF/HF ratio compared to normotensive pregnant and nonpregnant controls. Furthermore, normotensive pregnant women had lower values of SDNN, TP, and LF component in both absolute power and normalised units compared to nonpregnant females. The results confirm that normal pregnancy is associated with autonomic disturbances which get exaggerated in the state of preeclampsia.


Sign in / Sign up

Export Citation Format

Share Document