Vibration Exposure Research Articles

Noise and Vibration Risk Assessment for the Operators of Crawler Loaders

During work, earth-moving machines generate significant levels of noise and vibration that can be harmful for the operators; therefore the analysis of the noise and vibration conditions at the driving position is of great importance for the risk assessment. Compact loaders have become a pressing challenge as they are extremely hazardous referring to noise and vibration emissions, especially in their crawler version where further relevant noise and vibration are generated by the hard contact between track belt and ground. This paper reports the results of investigations carried out on three crawler compact loaders in different operating conditions. The main purpose was to investigate the noise and vibration values transmitted to the operators in some working conditions and use these data to obtain reliable estimates of the exposure to noise, to whole-body and to hand-arm transmitted vibrations, as well as to evaluate the related risk levels. Vibration signals transmitted to the operator were acquired on the seat and the machine control lever in accordance with the procedures specified in ISO 2631-1 and ISO 5349-1. At the same time, noise signals were acquired at the operator’s ear following the procedure reported in ISO 11201. Vibration signals were also acquired on the cabin floor with the main purpose to evaluate the effectiveness of the machine seats in reducing the vibration transmission. Finally, the noise and vibration exposure risks were evaluated on the basis of the health and safety requirements established in 2003/10/EC and 2002/44/EC Directives.

Internet of agriculture: Analyzing and predicting tractor ride comfort through supervised machine learning

The aim of this study is to improve ride comfort among tractor drivers by utilizing Internet of Things (IoT) technology and Machine Learning (ML) techniques to analyze and predict vibration exposure. The study explores the association between tractor ride characteristics, including average speed, tool depth, and pulling force, and ride comfort during actual rotary soil tillage operations. Ride comfort was evaluated by calculating the Overall Vibration Value (OVV) at three measurement locations (i.e., the floor, seat pan, and seat backrest). The study employed spectral analysis i.e., Fast Fourier Transform (FFT) and Power Spectral Density (PSD) to determine the predominant resonant frequencies. In addition, ML approaches i.e., Linear Regression (LR), Decision Tree Regressor (DTR), Support Vector Regression (SVR), Gaussian Process Regression (GPR), and Artificial Neural Network (ANN) were used to predict ride comfort response. Three hyperparameter optimization techniques, including Grid Search, Random Search, and Bayesian optimization were used. Tractor-tiller system was operated on a real agricultural field by five male tractor drivers. Vibration levels were measured along three translational axes at three measurement locations using a smart monitoring device based on the IoT concept. Average OVV magnitude was computed as 0.84 m/s2 i.e., exceeding the ISO 2631-1 (1997) threshold limits. FFT and PSD analysis revealed a variety of dominant frequencies, including resonance peaks at 2 Hz, 6–7 Hz, and 9–11 Hz. The analysis of variance (ANOVA) indicates that tractor speed and tool depth are significant variables (at the 5% level) in determining ride comfort. Regarding predictive accuracy, the ANN model exhibits the highest coefficient of determination of 0.90, followed by the SVM and GPR models with a coefficient of determination of 0.89. The DTR and LR models demonstrate slightly lower coefficient of determination values of 0.83 and 0.82, respectively. Furthermore, Bayesian optimization proved to be an effective approach in achieving more accurate predictions of tractor ride comfort. In general, the study outcomes can be utilized by tractor designers in numerous ways to optimize tractor design (such as suspension system, cab design, seat design, etc.) to improve tractor ride comfort in real field applications.

Ride comfort and segmental vibration transmissibility analysis of an automobile passenger model under whole body vibration

The examination of seated occupants’ ride comfort under whole-body vibration is a complex topic that involves multiple factors. Whole-body vibration refers to the mechanical vibration that is transmitted to the entire body through a supporting surface, such as a vehicle seat, when traveling on rough or uneven surfaces. There are several methods to assess ride comfort under whole-body vibration, such as subjective assessments, objective measurements, and mathematical models. Subjective assessments involve asking participants to rate their perceived level of discomfort or satisfaction during the vibration exposure, typically using a numerical scale or questionnaire. Objective measurements include accelerometers or vibration meters that record the actual physical vibrations transmitted to the body during the exposure. Mathematical models use various physiological and biomechanical parameters to predict the level of discomfort based on the vibration data. The examination of seated occupants ride comfort under whole-body vibration has been of great interest for many years. In this paper, a multi-body biomechanical model of a seated occupant with a backrest is proposed to perform ride comfort analysis. The novelty of the present model is that it represents complete passenger by including thighs, legs, and foot which were neglected in the past research. A multi-objective firefly algorithm is developed to evaluate the biomechanical parameters (mass, stiffness and damping) of the proposed model. Based on the optimized parameters, segmental transmissibilities are calculated and compared with experimental readings. The proposed model is then combined with a 7-dofs commercial car model to perform a ride comfort study. The ISO 2631-1:1997 ride comfort standards are used to compare the simulated segmental accelerations. Additionally, the influence of biomechanical parameters on most critical organs is analyzed to improve ride comfort. The outcomes of the analysis reveal that seated occupants perceive maximum vibration in the 3–6 Hz frequency range. To improve seated occupants' ride comfort, automotive designers must concentrate on the pelvis region. The adopted methodology and outcomes are helpful to evaluate protective measures in automobile industries. Furthermore, these procedures may be used to reduce the musculoskeletal disorders in seated occupants.

Development of a Digital Twin for a Hydraulic, Active Seat Suspension System

The vibrations induced by the soil irregularities and other equivalent disturbances on agricultural tractors represent a major cause of disease for tractor drivers. The reduction of vibration exposure of operators is a topic of interest for the (Italian) National Institute for Insurance against Accidents at Work (INAIL). Several passive, semi-active, and active solutions are commercially available for the seat or the cabin suspension to isolate the driver from the vibrations. A prototype of a hydraulic active suspension system for the operator seat has been developed in the laboratories of INAIL. In this paper, nonlinear multi-physics modeling of the prototype has been carried after an experimental identification of the actuation system and specifically of the control valve parameters. The model is adjusted to retrace the system’s response and is used as a digital twin of the physical prototype to develop and optimize the control system. An equivalent simplified model is obtained to design a proper control strategy for the active suspension system. Finally, the controller is tested on the digital twin of the system to assess its performance in isolating vibrations.

Features of Changes in Exogenous Heat Shock Proteins (HSP 27 and HSP 70) in Patients with Occupational Nervous System Pathology

The aim of the study was to identify and compare changes in serum concentrations of heat shock proteins (HSP 27 and HSP 27) in patients with occupational nervous system pathology induced by exposure to physical and chemical factors. Patients with sensorineural hearing loss (SHL), chronic mercury intoxication (CMI), vibration disease (VD) formed both under the influence of local vibration and combined exposure to general and local vibration were examined. As a result of comparative evaluation and analysis of serum concentrations of heat shock proteins, peculiarities in their change were revealed. In individuals with SHL and VD due to local vibration exposure, a decrease in serum HSP 70 concentration was recorded, and in patients with CMI and VD due to combined local and general vibration exposure, high HSP 27 concentrations were recorded. The examination of patients in the linked sample at 3 years showed the absence of statistically significant differences and the preservation of changes in the content of exogenous HSPs, which confirms the progressive course of these diseases. The conjugation of the number of T-lymphocyte and B-cells subpopulations with the change in serum HSP concentrations was established, which confirms the role of HSP 27 and 70 in the regulation of the immune response in VD and allows them to be regarded as markers of cellular and tissue damage in the chronic course of diseases.

The Effect of Physical Stress on the Quality of Mouse Sperm (Mus Musculus L.) Adult Males

Physical stress is one cause that can affect sperm quality. Vibration exposure as a form of physical stress that can stimulate the hormonal system so that it can disturb the process of spermatogenesis which consequently can decrease quality of sperm. This was a true experimental research with post test only control group design was done in the Integrated Laboratory of the Faculty of Medicine Halu Oleo University. Samples was 28 mice (Mus musculus L.) adult male, it were divided into 4 groups: control group (K), the treatment group 7 minutes 30 second (P1), 15 minutes (P2) and 30 minutes (P3) with the vibrations of 50 Hz for 21 days. Sperm quality include motility, viability, concentration and morphology. Data were analyzed descriptively test and Fisher's test. The results of this study indicated the significant differences (p<0,05) to quality of spermatozoa of adult mice.The conclusion of this study was vibration exposure at 50 Hz in the duration of 7 minutes 30 seconds, 15 minutes and 30 minutes for 21 days can decreased quality of sperm. It was suggested for further research can examined the levels of testosterone and histology on Leydig cells and Sertoli cells of the testis.

Investigation of Job Stress among Urban Bus Drivers Concerning Daily Noise and Vibration Exposure

Background and Objective: Bus drivers are exposed to harmful agents such as noise and vibration, which may increase the level of job stress among them. This study aimed to evaluate job stress among urban bus drivers concerning daily noise and vibration exposure. Materials and Methods: This cross-sectional study was conducted on 103 urban bus drivers in Hamadan in 2020. The drivers' exposure to noise and vibration was measured using Svan 104 and Svan 106, respectively. Their job stress was measured through the Phillippe L. Rice questionnaire. Data analysis was performed using SPSS (version 24). Results: The mean exposure of drivers to noise was 79.50 ± 3.51 dB. Their exposure levels to whole-body vibrations (WBV) and hand-arm vibrations (HAV) were 0.62 ± 0.16 and 0.44 ± 0.06 m/s2, respectively. Moreover, most drivers (87.4%) had severe job stress. A significant positive relationship was observed between noise and job stress (P=0.021), whereas there was no significant relationship between WBV, HAV, and job stress. Conclusion: Regarding the high prevalence of severe job stress among bus drivers and the positive correlation between noise and job stress, it is highly recommended that noise exposure be subsided through periodic services and maintenance, as well as using new buses instead of the old ones.

Experimental Device for Improved Cleaning and Calibration of Maize

All seed raw materials are cleaned from impurities from the mass, as well as spoiled. To obtain high-quality seed material, they need their main characteristics — size (width, length, thickness), weight, aerodynamic properties, etc. are sorted by in many modern grain cleaning machines, sorting is performed simultaneously with cleaning. Although there are state standards for seed marriage, quality control is often not carried out at the proper level by the control service. In this regard, there is an increased demand for cleaning and sorting machines. Analysis of the designs of existing seed cleaners and sorting equipment shows that the most promising in terms of research are devices with working bodies made in the form of flat sieves and regular vibration exposure. Taking into account the urgency of the issue, this research work is aimed at constructive and technological improvement of the technology and sorting device at the stage of selection of corn grain intended for sowing.

Cytokine profile in patients with vibration disease, aggravated by hypertension and obesity

Comorbid diseases which include arterial hypertension (AH) accompanied by overweight, and vibration disease (VD) are known to contribute to the mutual aggravation of occupational and cardiovascular pathology. Despite numerous studies indicating that some changes of immune system are observed when exposed to vibration, the contribution of cytokines to the comorbid course of vibration disease has not been sufficiently studied. The aim of the work is to evaluate the role of inflammatory mediators in development of hypertension and obesity in vibration disease.The cytokine profile parameters were determined by ELISA immunoassay using “Vector-Best” test systems. Some unidirectional changes in serum cytokine concentrations were found in patients with VD complicatedby AH, and those with VD without AH, being characterized by increase in pro-inflammatory IL-1β, TNFα, IL-17, anti-inflammatory IL-4 and IFNγ, and a decrease in multifunctional IL-2 cytokinem, relative to the comparison group. The groups with versus without AH differed in compensatory increase of anti-inflammatory IL-10 in the latter group. At the same time, all patients with combined VD and AH had excessive body weight, with grade 1 obesity in half of the cases, thus being significantly different from those with VD without AH. It is shown that IL-1β, IL-2, IL-4, IL-8, TNFα play an apparent role in the development of obesity. The greatest contribution is observed for IL-1β, as evidenced by the quantitative relationship of body mass index with its concentrations as assessed by logistic regression analysis. The limitation of this study may be a small sample size.It was found that the unidirectional changes in cytokines when compared to the comparison group were revealed in patients with VD complicated by AH, and in patients with VD without AH. In the subjects with VD and AH, these changes were more pronounced, which may suggest the hypertension is an aggravating factor. The established relationship between individual cytokines (IL-1β, IL-2, IL-4, IL-8, TNFα) and BMI indicates their participation in development of obesity. All these findings may provide a basis for development of preventive and therapeutic measures that reduce the risk of hypertension and obesity in the people working under permanent exposure of vibration.

Study on local bond behaviors between steel bars and high-strength concrete exposed to early disturbances

This paper investigates the effects of early vibration exposure on the local bond behaviors between deformed steel bars and high-strength concrete (HSC). The effects of steel fiber and vibration intensity (ranging from static to peak particle velocity (PPV) of 10 cm/s) on the deterioration laws of bond performances and mechanisms were revealed. Finally, an empirical prediction model was developed to uniformly describe the bond stress-slip relations of specimens subjected to different vibration levels. Results indicated that early vibration could produce separation gaps and the surrounding viscous layers around steel bars, leading to the reduction/elimination of initial debonding resistances. Besides, the failure mode of pull-out specimens may alter due to the degradation of concrete. The bond stiffness of HSC is more vulnerable to environmental vibration (up to 62.6%), followed by bond strength (39.4%) and compressive strength (33.7%). The bond toughness of specimens, especially with the addition of steel fibers, is less sensitive to vibration (29.8%/6.8% for HSC/HSFRC). The increases in concrete strength grades and additions of fibers significantly enhance the threshold resistance to early vibration, making it a recommended solution for vibration scenarios. Using a consistent expression, the proposed empirical model reasonably reproduces bond stress-slip curves of specimens with/without vibration exposure.

Exposure to hand-held vibrating tools and biomarkers of nerve injury in plasma: a population-based, observational study

ObjectivesTo analyse potential biomarkers for vibration-induced nerve damage in a population-based, observational study.DesignProspective cohort study.SettingMalmö Diet Cancer Study (MDCS), Malmö, Sweden.ParticipantsIn a subcohort of 3898 individuals (recruited 1991–1996) from MDCS...

Real‐time vibration monitoring and analysis of agricultural tractor drivers using an IoT‐based system

AbstractAgricultural tractor drivers experience a high amplitude of vibration, especially during soil tillage operations. In the past, most research studied vibration exposure with more focus on the vertical (z) axis than on the fore‐and‐aft (x) and lateral (y) axes. This study examines how rotary soil tillage affects the vibration acceleration and frequency, and the power spectral densities (PSDs) at the seat pan and head along three translational axes in a real‐field multiaxis vibration context. Moreover, this study aimed to identify the characteristics of the seat‐to‐head transmissibility (STHT) response to identifying the most salient resonant frequencies along the x‐, y‐, and z‐axes. Nine (9) male tractor drivers operated the tractor with a mounted rotary tiller throughout the soil tillage process. In the event of a COVID‐19 pandemic, and to respect social distancing, this study developed an Internet of Things (IoT) module with the potential to integrate with existing data loggers for online data transmission and to make the experimentation process more effective by removing potential sources of experimenter errors. The raw acceleration data retrieved at the seat pan and the head were utilized to obtain daily exposure (A(8)), PSDs, and STHT along the x‐, y‐, and z‐axes. The vibration energy was found to be dominant along the z‐axis than the x‐ and y‐axes. A(8) response among tractor drivers exceeds the exposure action value explicitly stated by Directive 2002/44/EU. PSDs along the x‐, y‐, and z‐axes depicted the low‐frequency vibration induced by rotary soil tillage operation. The STHT response exhibited a higher degree of transmissibility along the y‐ and z‐axes when compared with that along the x‐axis. The frequency range of 4–7 Hz may plausibly be associated with cognitive impairment in tractor drivers during rotary soil tillage.

N°13 – Peripheral neuropathy among workers with Hand-arm vibration exposure

N°13 – Peripheral neuropathy among workers with Hand-arm vibration exposure

Examination of the Protein Drug Supply Chain in a Swedish University Hospital: Focus on Handling Risks and Mitigation Measures

Protein drugs, such as monoclonal antibodies, have proved successful in treating cancer and immune system diseases. The structural complexity of these molecules requires careful handling to ensure integrity and stability of the drug. In this study, a failure mode and effects analysis was performed based on a Gemba Walk method in a Swedish University Hospital. The Gemba Walk is focused on pharmacists observing the actual supply process steps from distributor, pharmacy cleanroom to patient administration. Relevant protein drugs are chosen based on sales statistics within the hospital and the corresponding wards were observed. Further is the Double Diamond design method used to identify major risks and deliver mitigation strategies. The study identified potential stress factors such as temperature, shock by impact, shaking, vibration and light exposure. There were also risks associated with porters’ and healthcare professionals’ lack of awareness and access to information. These risk factors may cause loss of efficacy and quality of the protein drug, potentially leading to patient safety concerns. In this study, a simulation is also performed to list measures that theoretically should be in place to ensure the quality of the protein drug, for example validated and protocol-based compounding in cleanroom, training and validated transports.

Daily Vibration Exposure in the Context of State and European Legislature: A Case Study among Chainsaw Operators in Croatia

The Ordinance on Occupational Safety and Health in Forestry proposes no more than 4 h of effective chainsaw work daily, while EU Directive 2002/44/EC proposes an EAV of 2.5 m/s2, and an ELV of 5 m/s2. The aim of this paper was to compare and assess the viability of the proposed restrictions. A case study in Croatia including 91 felled and processed trees, a detailed time study, and vibration magnitude measuring on European beech wet wood in compliance with ISO 5349-1:2001 and ISO 5349-2:2001 standards were performed. The results implied that tree species, processing method, and DBH have no influence on the time structure of working hours. Using bigger and more powerful chainsaws resulted in higher A(8) values; it was also noted that the right hand is more exposed. On average, none of the observed chainsaws exceeded 5 m/s2 of A(8). It can be concluded that state legislature, which allows a maximum of 4 h of chainsaw work a day, is appropriately protecting chainsaw workers from vibration exposure, but is also obsolete (1986) as it only uses the time limit. In contrast, European legislature requires a methodical approach to A(8) calculation and leaves room for individual evaluation of specific chainsaw work, which opens up possibilities of extending or shortening some chainsaw operations.

Effects on blood parameters from hand-arm vibrations exposure

Vibration exposure from handheld tools can affect the hands with neurological symptoms and vibration-induced Raynaud's phenomenon (VRP). The underlying pathophysiological mechanisms are not fully known, however, changes in the composition of blood parameters may contribute to VRP with an increase in blood viscosity and inflammatory response. The aim of this study was to examine the effect on blood parameters in capillary blood from fingers that had been exposed to a vibrating hand-held tool. This study involved nine healthy participants who had been exposed to vibration and an unexposed control group of six participants. Capillary blood samples were collected before and after vibration exposure for the exposed group, and repeated samples also from the control group. The exposed groups were exposed to vibration for a 15-min period or until they reached a 5.0m/s2 vibration dose. Analysis of blood status and differential counting of leucocytes was performed on the capillary blood samples. The results of the blood samples showed an increase in mean value for erythrocyte volume fraction (EVF), hemoglobin, red blood cell count, white blood cell count and neutrophils, as well as a decrease of mean cell volume, mean cell hemoglobin, and mean cell hemoglobin concentration. The increase of EVF and neutrophils was statistically significant for samples taken from the index finger but not the little finger. Even though the study was small it showed that an acute vibration exposure to the hands might increase EVF and neutrophilic granulocytes levels in the capillary blood taken from index fingers.

Adaptation of the hearing analyzer under vibration noise exposure in volunteers: Ways of prevention

BACKGROUND: The negative effect of impulse noise and vibration when using small arms on the auditory analyzer in athletes is less investigated and justifies the need for an extended study of volunteers with normal hearing. The study of the initial characteristics of the impulse noise and vibration effects of sports weapons on the auditory analyzer will make it possible to determine the early risk factors for the occurrence of high-frequency hearing loss in shooters by the number of shots from sports weapons and the recovery time of auditory function. AIMS: To conduct a comparative analysis of the effect of impulse noise and vibration exposure depending on the technical characteristics of small arms on volunteers with normal hearing and, based on the results obtained, unify the methods of forecasting and prevention. MATERIALS AND METHODS: At the Department of Otorhinolaryngology of the South Ural State Medical University of the Ministry of Health of Russia, 30 fifth-year students were examined following continuous recruitment of volunteers between September 2022 and November 2022. All interviewed participants gave voluntary written consent to participate in the survey and to the test level of impulse noise. Based on the current regulatory documents, all volunteers were surveyed and underwent audiological and vestibulometric studies, the technical characteristics of noise and vibration exposure as a risk factor for the early development of presbycusis were determined, and ways of preventing hearing loss through lifestyle were proposed. RESULTS: The comparative analysis of the influence of impulse noise and vibration effects showed a dependence on the weight of the small arms cartridge, number of shots, and adaptation time of the auditory analyzer in volunteers with normal hearing considering the changes in the high-frequency spectrum of increasing audiometry thresholds from the average value of indicators. CONCLUSIONS: The use of active explanatory propaganda among young people on a careful attitude to the physiological state of the cochleovestibular apparatus avoids the risk of early presbycusis development.

A Comparison between the Latest Models of Li-Ion Batteries and Petrol Chainsaws Assessing Noise and Vibration Exposure in Cross-Cutting

Chainsaw operators are exposed to many hazards that can lead to health problems. The two most frequently documented ergonomics threats in the use of chainsaws are noise and vibration exposure. Since the use of battery chainsaws is increasing due to the growing improvements in battery life and power, the study aims to compare the difference in terms of noise emission and vibration levels of the following two new models of chainsaws: the battery-powered Stihl MSA 300 and the petrol-powered Stihl MS 261 C-M. Black pine and European beech logs were cross-cut in order to evaluate both noise and vibration exposure. The results show that the use of battery-powered chainsaws, in comparison to the petrol one, can reduce the daily vibration exposure by more than 51% and the noise dose by 11%. The daily vibration exposure of 1.60 ms−2 and 1.67 ms−2 measured for the battery-powered chainsaw on Black pine and on European beech, respectively, is far from the daily exposure action value set by the EU directives for health and safety requirements (2.5 ms−2). On the contrary, the daily noise exposure for the battery chainsaw was 93 dB(A), exceeding the upper exposure action value of 85 dB(A).

Optimization of Daily Vibration Dose during Different Ride Parameters among Tractor Driving

<div>This research examined tractor operators’ daily vibration exposure A(8) with different input riding parameters, i.e., average speed (m/s) (2.78, 3.89, 5.0), body mass (BM) (kg/m<sup>2</sup>) (35.3, 32.6, 25.4), and different terrain types (brick, farm, and tar roads). To arrange the systematic sequence of experiments, Taguchi’s L9 orthogonal array has been selected for this study. The signal-to-noise ratio (SNR) is calculated to analyze the overall influence of input parameters over the output parameters. In this study, it is found that A(8) responses exceeded the recommended action value among all the tractor operators according to ISO 2631-1 (1997). The average speeds and various terrain conditions were shown to be the most influential significant variables (<i>p</i> ≤ 0.05), with percentage contributions of 53.71% and 11.53%, respectively. The predicted linear and linear interaction values in a regression model are quite similar to the experimental values, with mean error percentages of 3.89% and 2.27%, respectively. As comfort is essential for the tractor operator, the results of this research may be used in the design of tractor seats to improve comfort. The approach is unique in the Indian context for the comfort of the tractor driver.</div>

Advances in Wearable Piezoelectric Sensors for Hazardous Workplace Environments.

Recent advances in wearable energy harvesting technology as solutions to occupational health and safety programs are presented. Workers are often exposed to harmful conditions-especially in the mining and construction industries-where chronic health issues can emerge over time. While wearable sensors technology can aid in early detection and long-term exposure tracking, powering them and the associated risks are often an impediment for their widespread use, such as the need for frequent charging and battery safety. Repetitive vibration exposure is one such hazard, e.g., whole body vibration, yet it can also provide parasitic energy that can be harvested to power wearable sensors and overcome the battery limitations. This review can critically analyze the vibration effect on workers' health, the limitations of currently available devices, explore new options for powering different personal protective equipment devices, and discuss opportunities and directions for future research. The recent progress in self-powered vibration sensors and systems from the perspective of the underlying materials, applications, and fabrication techniques is reviewed. Lastly, the challenges and perspectives are discussed for reference to the researchers who are interested in self-powered vibration sensors.