On the Influence of Freight Trains on Humans: A Laboratory Investigation of the Impact of Nocturnal Low Frequency Vibration and Noise on Sleep and Heart Rate

Background: Stress is one of the risk factors for cardiovascular disease and decreased heart rate variability is associated to increased mortality in some cardiac diseases. The aim of the study was to assess the impact of perceived stress on cardiac autonomic regulation in young healthy volunteers. Methods: 35 young healthy volunteers (19 to 29 years old, 6 men) from a Brazilian population were assessed for perceived stress by the translated and validated Perceived Stress Scale (PSS, 14 questions) and had the R-R intervals recorded at rest on supine position (POLAR RS800CX) and analyzed (5 minutes, Kubius HRV software) by Fast-Fourier Transform for quantification of Heart Rate Variability (HRV). Results: Average data (±SD) for age, heart rate, BMI, waist circumference and percentage of body fat (%BF) were: 21.3±2.7 years; 65.5±7.9 bpm; 22.3±1.9 Kg/m 2 ; 76.0±6.1 cm and 32.1±6.6%; respectively. The mean score for the PSS-14 was 23.5±7.2 and for the HRV parameter as follow: SSDN=54.8±21.2ms; rMSSD=55.9±32.2ms; low-frequency (LF)= 794.8±579.7ms 2 ; High-frequency (HF)= 1508.0±1783.0 ms 2 ; LF(n.u.)= 41.1±16.2; HF(n.u.)= 58.9±16.2; LF/HF=0.89±0.80 and Total power (TP)= 3151±2570ms 2 . Spearman nonparametric correlation was calculated and there was a significant correlation of PSS-14 scores and LF (ms 2 ) (r=−0.343; p= 0.044). Other HRV variables did not shown significant correlation but also had negative values for Spearman r (TP r=−0.265, p=0.124; HF r=−0.158; SSDN r=−0.207; rMSSD r=−0.243, p=0.160). LF/HF and LF(n.u.) did not correlate to PSS-14 having Spearman r very close to zero (LF/HF r=−0.007, p=0.969; LF(n.u.) r=−0.005, p=0.976). No correlation was found for HRV parameters and BMI and there was a trend for statistical correlation of %BF and LF (ms 2 ) (r=−0.309, p=0.071). Conclusions: These data demonstrate a possible association of perceived stress level and HRV at rest. Changes in LF can be a consequence of both sympathetic and parasympathetic activity, however, analyzing the other variables HF, TP, SSDN and rMSSD (all negative Spearman r) and due to the lack of changes in LF/HF ratio and LF(n.u.) we interpret that increased stress may be associated to decrease in overall heart rate variability. These changes were seen in healthy individuals and may point out an important mechanism in cardiovascular disease development.

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Evaluation of CFRP Hole Quality in Low Frequency Vibration-Assisted Dry Drilling of CFRP/Ti Stacks

Volume 4: Processes ◽

10.1115/msec2018-6382 ◽

2018 ◽

Cited By ~ 1

Author(s):

Haojun Yang ◽

Yan Chen ◽

Jiuhua Xu

Keyword(s):

Feed Rate ◽

Kinematic Model ◽

Mechanical Damage ◽

Low Frequency ◽

Spindle Speed ◽

Hole Quality ◽

Drilling Force ◽

Low Frequency Vibration ◽

The Impact ◽

Conventional Drilling

Low frequency vibration assisted drilling (LFVAD) is regarded as one of the most promising process in CFRP/Ti stacks drilling. This work carries the investigation of the difference between conventional drilling and LFVAD based on kinematic model. The experiments are conducted under varied vibration amplitude to a specific feed rate, also under varying spindle speeds, feed rates when the ratio of amplitude to feed rate is fixed. Then the hole quality of CFRP is evaluated based on the analysis of drilling force, chip morphology, chip extraction. The results show that there is rarely no difference between conventional drilling and LFVAD in drilling mechanism when the drilling diameter is over 1 mm. Because the impact effect caused by drill vibration is already weak. It is found that the severe mechanical damage of the CFRP holes surface could be significantly reduced due to the fragmented chips obtained in vibration drilling. The maximum instantaneous feed rate combined with feed rate and amplitude plays a significant role in CFRP hole quality. Lower maximum instantaneous feed rate results in better hole wall quality and less entry delamination. Spindle speed has no visible influence on entry delamination, while higher spindle speed improves the hole surface quality due to the resin coating phenomenon.

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The Impact of Sound Exposure on Heart Rate Variability in Adolescent Students

Physiological Research ◽

10.33549/physiolres.933882 ◽

2018 ◽

pp. 695-702 ◽

Cited By ~ 4

Author(s):

M. VETERNIK ◽

I. TONHAJZEROVA ◽

J. MISEK ◽

V. JAKUSOVA ◽

H. HUDECKOVA ◽

...

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Low Frequency ◽

Sound Intensity ◽

Sine Wave ◽

Adolescent Students ◽

Sound Exposure ◽

Cardiac Autonomic Regulation ◽

The Impact ◽

First Time

Previous studies of physiological responses to music and noise showed the effect on the autonomic nervous system. The heart rate variability (HRV) has been used to assess the activation of the sympathetic and the parasympathetic nervous systems. The present study was aimed to examine HRV with exposure to four sine-wave pure tones (20 Hz, 50 Hz, 2 kHz and 15 kHz) in an environment where the sound intensity exceeded level 65 dB (A-weighted). The participants (20 adolescent girls) were lying in supine position during exposure protocol divided into 6 periods, the first time with generated sounds and the second time without sounds. In the protocol without sound exposure, the low frequency band of the HRV spectrum was increased compared to the basal state before examination (period_1: 6.05±0.29 ms2 compared to period_5: 6.56±0.20 ms2, p<0.05). The significant increase of root Mean Square of the Successive Differences (rMSSD, period_1: 4.09±0.16 s compared to period_6: 4.33±0.12 s, p<0.05) and prolongation of R to R peak (RR) interval (period_1: 889±30 ms compared to period_5: 973±30 ms, p<0.001) were observed in the protocol without sound exposure comparing to the protocol with sound exposure where only bradycardia was observed. Contrary to rather polemical data in literature our pilot study suggests that sounds (under given frequencies) have no impact on the heart rate variability and cardiac autonomic regulation.

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Study on Looseness and Impact - Rub Coupling Faults of a Vertical Dual-Disk Cantilever Rotor- Bearing System

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.353-358.2479 ◽

2007 ◽

Vol 353-358 ◽

pp. 2479-2482

Author(s):

Yan Jun Lu ◽

Zhao Hui Ren ◽

Hong Chen ◽

Nai Hui Song ◽

Bang Chun Wen

Keyword(s):

Finite Element ◽

Low Frequency ◽

Element Model ◽

Coupling Faults ◽

Mechanics Model ◽

Low Frequency Vibration ◽

Rotor Bearing ◽

Impact And Rubbing ◽

The Impact ◽

Bearing System

Because of wrong setting or long-term running of rotating machinery, the looseness may ouur in the bearing seats or bases. And also bring impact and rubbing of rotor-stator, That is the looseness and rub-impact coupling fault. In the paper,a mechanics model and a finite element model of a vertical dual-disk cantilever rotor- bearing system with coupling faults of looseness and rub-impact are set up. Based on the nonlinear finite element method and contact theory, the dynamical characteristices of the system under the influence of the looseness rigidity and impact-rub clearance is studied. The results show that the impact-rub of rotor-stator can reduce the low frequency vibration caused by looseness, and the impact-rub caused by looseness has obvious orientation. Also, the conclusion of diagnosing the looseness and rub-impact coupling faults is given in the end of the paper.

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Changes in Heart Rate Variability of Depressed Patients after Electroconvulsive Therapy

Cardiovascular Psychiatry and Neurology ◽

10.1155/2012/794043 ◽

2012 ◽

Vol 2012 ◽

pp. 1-8 ◽

Cited By ~ 3

Author(s):

Erica B. Royster ◽

Lisa M. Trimble ◽

George Cotsonis ◽

Brian Schmotzer ◽

Amita Manatunga ◽

...

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Depressive Symptoms ◽

Electroconvulsive Therapy ◽

Low Frequency ◽

Frequency Component ◽

High Frequency Component ◽

Acute Changes ◽

The Impact

Objective. As few, small studies have examined the impact of electroconvulsive therapy (ECT) upon the heart rate variability of patients with major depressive disorder (MDD), we sought to confirm whether ECT-associated improvement in depressive symptoms would be associated with increases in HRV linear and nonlinear parameters. Methods. After providing consent, depressed study participants (n=21) completed the Beck Depression Index (BDI), and 15-minute Holter monitor recordings, prior to their 1st and 6th ECT treatments. Holter recordings were analyzed for certain HRV indices: root mean square of successive differences (RMSSD), low-frequency component (LF)/high-frequency component (HF) and short-(SD1) versus long-term (SD2) HRV ratios. Results. There were no significant differences in the HRV indices of RMSDD, LF/HF, and SD1/SD2 between the patients who responded, and those who did not, to ECT. Conclusion. In the short term, there appear to be no significant improvement in HRV in ECT-treated patients whose depressive symptoms respond versus those who do not. Future studies will reveal whether diminished depressive symptoms with ECT are reliably associated with improved sympathetic/parasympathetic balance over the long-term, and whether acute changes in sympathetic/parasympathetic balance predict improved mental- and cardiac-related outcomes.

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Heart rate variability in persons of Tajik nationality during adaptation

RUDN Journal of Medicine ◽

10.22363/2313-0245-2021-25-4-306-312 ◽

2021 ◽

Vol 25 (4) ◽

pp. 306-312

Author(s):

Sarvar S. Raufov ◽

Sergey N. Shilov

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Activity Index ◽

Statistical Significance ◽

Low Frequency ◽

The Body ◽

Regulatory Mechanisms ◽

Regulatory Systems ◽

Adaptive Capabilities ◽

The Impact

Relevance . Maintaining the health of migrants while adapting to the new climatic and geographical conditions of residence is an urgent task. The impact of non-specific factors on the body of migrants in new climatogeographic conditions leads to the strain of regulatory and adaptive mechanisms, and in extreme cases to their failure. Objective - to determine the features of heart rate variability in young Tajiks, depending on the type of temperament living in Krasnoyarsk for more than a year. Materials and Methods: A study of heart rate variability in 63 Tajiks aged 18-40 years with different types of temperament, living in Krasnoyarsk for more than a year, was conducted. The types of temperament were determined by indices in accordance with the method of identifying VP-types of temperament according to E.Yu. Petrosyan, Yu. I. Savchenkov. The following indicators of heart rate variability (HRV) were evaluated: heart rate, the power of the high-frequency, low-frequency and very low-frequency spectrum (BV, MV-2, MV-1) of the HRV component, the voltage index of regulatory systems (IN), the centralization index (CI) and the activity index of regulatory systems. To assess the statistical significance of the differences between the samples, the Students criteria were used. Results and Discussion. It was revealed that migrants with an intense type of temperament after moving to a new place of residence increased the indicators of heart rate, BV and IN. At the same time, in the studied groups with a calm and adequate type of temperament, the power of BV was significantly reduced, with an increase in heart rate and CI. The conclusion is made about the influence of typological features of temperament on HRV indicators, when adapting to new climatogeographic living conditions. Individuals with an adequate type of temperament demonstrate the normal functioning of the adaptive capabilities of the body. In individuals with the calm type, an increase in the tension of the regulatory mechanisms was revealed. Conclusion . Significant changes in HRV are demonstrated by migrants with an intense type of temperament, in particular, they are characterized by a high voltage of regulatory mechanisms.

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Spontaneous diameter oscillations of the radial artery in humans

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1993.264.6.h2080 ◽

1993 ◽

Vol 264 (6) ◽

pp. H2080-H2084 ◽

Cited By ~ 10

Author(s):

D. Hayoz ◽

Y. Tardy ◽

B. Rutschmann ◽

J. P. Mignot ◽

H. Achakri ◽

...

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Radial Artery ◽

Contractile Activity ◽

Low Frequency ◽

Middle Finger ◽

Oscillatory Behavior ◽

Internal Diameter ◽

Arterial Diameter ◽

The Impact

In this study we investigated whether there exists a periodic contractile activity of the radial artery, and we evaluated the impact of such an oscillatory behavior on the mechanical properties of this medium-sized muscular vessel. The internal diameter of the right radial artery was measured noninvasively in six healthy male volunteers aged 18–42 yr using a high-precision ultrasonic echo-tracking device. Blood pressure was simultaneously recorded on the same side at the middle finger by photoplethysmography. The electrical activity of the heart was monitored during the entire experiment by electrocardiography. The frequency components of the arterial diameter, blood pressure, and heart rate were obtained using spectral analysis. Under resting conditions, the radial arterial diameter exhibited a spontaneous oscillation with a period ranging from 45 to 70 s and an amplitude of 80 +/- 14 microns (+/- SE). No very low-frequency mode (< or = 0.02 Hz) was identified in either heart rate or blood pressure. These diameter oscillations affected the distensibility-pressure curves acquired simultaneously. Thus the 3–4% oscillatory variation in arterial diameter was paralleled by a 1.5- to 2-fold change in distensibility. These low-frequency oscillations of large arteries seem to be mediated by an intrinsic vascular mechanism.

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Performance of a New Fine Particle Impact Damper

Advances in Acoustics and Vibration ◽

10.1155/2008/140894 ◽

2008 ◽

Vol 2008 ◽

pp. 1-6 ◽

Cited By ~ 7

Author(s):

Yanchen Du ◽

Shulin Wang ◽

Yan Zhu ◽

Laiqiang Li ◽

Guangqiang Han

Keyword(s):

Fine Particle ◽

Mechanical Vibration ◽

Low Frequency ◽

Particle Impact ◽

Momentum Exchange ◽

Impact Damper ◽

Low Frequency Vibration ◽

Cantilevered Beam ◽

The Impact ◽

First Time

The energy dissipation mechanisms of conventional impact damper (CID) are mainly momentum exchange and friction. During the impact process, a lot of vibration energy cannot be exhausted but reverberated among the vibration partners. Besides, the CID may produce the additional vibration to the system or even amplify the response in the low-frequency vibration. To overcome these shortcomings, this paper proposes a new fine particle impact damper (FPID) which for the first time introduces the fine particle plastic deformation as an irreversible energy sink. Then, the experiments of the cantilevered beam with the CID and that with the FPID are, respectively, carried out to investigate the behavior of FPID. The experimental results indicate that the FPID has a better performance in vibration damping than in the CID and the FPID works well in control of the vibration with frequency lower than 50 Hz, which is absent to the non-obstructive particle damper. Thus, the FPID has a bright and significant application future because most of the mechanical vibration falls in the range of low freqency.

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Impact of personality-oriented programs of physical rehabilitation on the heart rate variability in women with post-mastectomy syndrome

Physiotherapy ◽

10.1515/physio-2016-0007 ◽

2017 ◽

Vol 24 (2) ◽

Cited By ~ 2

Author(s):

Tatiana Odinets ◽

Yuriy Briskin

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Low Frequency ◽

Radical Mastectomy ◽

Frequency Component ◽

Physical Rehabilitation ◽

Stress Index ◽

Heart Rate Variability Analysis ◽

Rehabilitation Programs ◽

The Impact

AbstractIntroduction. The aim of the study was to determine the effect of personality-oriented physical rehabilitation programs on the heart rate variability in women with post-mastectomy syndrome. Methods. The following methods were applied: theoretical analysis of scientific and methodologic literature data, heart rate variability analysis, and mathematical statistical methods. The subjects of the study were 50 women with late symptoms of post-mastectomy syndrome. The study was conducted during the ambulatory rehabilitation stage after Madden radical mastectomy. All the indicators of the heart rate variability were equivalent in the main and comparison groups at the beginning of rehabilitation. The impact of training was examined every 6 months over the course of a year. Results. Measurements were taken three times: at the beginning of rehabilitation and after 6 and 12 months. It was found that most of the investigated parameters of heart rate variability in both groups steadily improved during the year of rehabilitation. The average values of stress index and amplitude of mode after 12 months of rehabilitation were lower in the main group than in the comparison group but the values of the standard deviation of normal-to-normal intervals and the very low-frequency component of the spectrum were better by 6.48 ms (p < 0.05) and 203.29 ms2 (p < 0.05), respectively. Conclusions. The personality-oriented programs of physical rehabilitation were effective in augmenting heart rate variability and restoring autonomic balance in patients with post-mastectomy syndrome.

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Dynamic Modeling and Analysis of Space Manipulator Considering the Flexible of Joint and Link

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.823.270 ◽

2013 ◽

Vol 823 ◽

pp. 270-275 ◽

Cited By ~ 1

Author(s):

Pan Dong ◽

Zhao Yang ◽

Zhang Yue ◽

Wei Cheng ◽

E Wei

Keyword(s):

Joint Stiffness ◽

Low Frequency ◽

Flexible Link ◽

Large Space ◽

Flexible Joint ◽

Modeling And Analysis ◽

Position Accuracy ◽

Low Frequency Vibration ◽

Space Manipulators ◽

The Impact

The long length, light weight, low frequency, flexible joint and link of large space manipulators impact dynamic stability and position accuracy seriously. In this paper, dynamical model of space flexible manipulators system is build base on Lagrange method. With three DOF manipulators as the research object, the impact of flexible link, joint stiffness and clearance on the system frequency and end position accuracy of manipulator is simulated and analyzed. The results indicate that the flexible joint lead to low frequency vibration and flexible link lead to high frequency vibration. Low frequency vibration is the dominant impact of end position accuracy, Flexible joint have greater impact on the dynamic characteristics of system than that of flexible link.

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