Download or read book Development of a Methodology for Integrated Performance Analyses of Anti vibration Gloves for Controlling the Hand transmitted Vibration written by Yumeng Yao and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hand-transmitted vibration (HTV) arising from hand-held power tools has been associated with an array of disorders of the hand-arm system, collectively referred to as the hand-arm vibration syndrome (HAVS). The risk of HAVS among hand-held power tools operators has been related to the nature of HTV exposure and the mechanical coupling of the hand with a tool handle, which is neglected in the current standardized exposure assessment method (ISO 5349, 2001). Anti-vibration (AV) gloves are considered as convenient and effective means to reduce exposure to HTV. The effectiveness of AV gloves is, invariably, assessed on the basis of the handle vibration transmitted to the palm of the hand. The method does not consider the vibration responses of the fingers, which differ significantly from that of the palm. The AV gloves adversely influence the manual dexterity and grip strength of the operators, which are considered as primary factors discouraging the usage of AV gloves. The current standardized method, however, does not consider the loss of dexterity and grip strength caused by wearing these gloves. This thesis proposes a methodology for evaluating the integrated performance of AV gloves, considering the distributed vibration transmission to the palm and fingers through gloves, manual dexterity and grip strength. In order to establish the methodology, independent experiments were designed to quantify each performance measure. Three series of experiments were designed to evaluate vibration responses distributed over the palm and fingers, manual dexterity and grip strength performance of gloves. Each experiment design involved ten different gloves and 15 adult male subjects. Viscoelastic properties of vibration isolation materials used in the AV gloves were also characterized under a constant preload. In the first series, the fine fingers and hand dexterity were investigated using the Two-Hand Turing & Placing Minnesota and ASTM F2010 methods. Subsequently, the handle vibration transmitted to the palm and mid phalanges of the index and middle fingers of the glove hand were measured along the three translational axes using the palm and fingers' adapters, respectively. In the final series, the influence of AV gloves on the operator's grip strength were investigated via direct as well as indirect methods. A flexible thin-film hand sensor was designed and verified for direct measurement of the contact force developed at the rigid as well as flexible hand-handle, and hand-glove interfaces. The activities of four different forearm muscles were also measured via surface electromyography (EMG) under different hand grip forces imposed by the gloved hand.The correlations among the individual performance measures of AV gloves and the material properties were analyzed via Pearson's correlation coefficient, which provided essential knowledge on the roles of design factors and the design guidance. A relationship among the hand grip, push and contact forces imposed on flexible hand-handle was developed via multiple linear regression analysis. The individual measures of AV gloves were also analyzed via two-factor repeated analyses of variance (ANOVA) and multivariate analysis of variance (MANOVA) to evaluate significance of different independent variables such as glove type, test method, frequency range, and hand grip force. The glove type yielded significant effect on all the measures (p0.05). Post-Hoc tests were subsequently conducted via Bonferroni and Tukey HSD (honest significant difference) test for discriminating difference among the gloves. The combination of extensor carpi radialis longus (ECR) and flexor carpi radialis (FCR) muscles activities revealed highest sensitivity to discriminate among gloves and could serve as an effective indirect measure of the grip strength performance. Increasing the glove thickness resulted in improved vibration isolation by the glove but reduced manual dexterity and enhanced muscles activities. Strong correlation was observed between the material stiffness and wh-weighted palm vibration transmissibility in the high frequency range (r0.90), while a weak correlation was evident between the manual dexterity and the wp-weighted fingers' vibration transmissibility. Strong positive correlations were observed among the palm vibration isolation, material properties and material thickness in the 25-1250 Hz frequency range.The results also revealed conflicting glove design requirements imposed by the individual measures. A methodology based on analytical hierarchy process (AHP) is proposed to identify weightings for the conflicting performance measures for the given work condition, classified in accordance with the frequency ranges of predominant vibration (low and high), as defined in ISO-10819 (2013) together with assembly/disassembly tasks. An integrated performance index is identified and applied to rank five different AV gloves with known individual performance measures for identifying the most desirable glove.

Download or read book Vibration Transmission Characteristics and Grip Strength Preservation and Anti vibration Gloves written by Karim Hamouda and published by . This book was released on 2016 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exposure to hand-transmitted vibration (HTV) arising from operating hand-held power tools has been associated with various health consequences such as vascular, neurological and musculoskeletal disorders of the hand-arm system, which are collectively termed as hand-arm vibration syndrome (HAVS). In order to decrease the effects of HTV, substantial efforts have been made to protect the operator from the vibrating tools and decrease the vibration exposure. One of the convenient means to isolate the hand from the vibrating tool handle is the anti-vibration (AV) glove. These gloves are constructed from different isolation materials, which are capable of reducing the vibration transmitted to the hands. Vibration isolation performance of AV gloves has been widely evaluated based on measurements of vibration transmitted to the palm of the hand following the method recommended in ISO 10819 (2013). The standard does not require the measurement of transmitted vibration at the fingers side, and consider similar vibration isolation performance of the gloves at the palm and the fingers. The standard also does not address the effect of AV gloves on the hand grip strength, which can be a reason for not wearing these gloves by tool operators. This dissertation seeks to develop a finger adapter capable of measuring the transmitted vibration to fingers and assess the AV gloves based on the integrated performance of vibration isolation at palm and fingers as well as the grip strength preservation. Three different finger adapters (a steel ring, a split ring and a Velcro adapter), each instrumented with a tri-axial accelerometer, were developed and assessed to measure the vibration transmitted to the index and the middle fingers. The assessment of the three adapters showed that the Velcro adapter exhibit relatively lower inter-subject variability and yields resonably good agreements with the data reported in a recent study that measured fingers vibration using laser vibrometer. The effectiveness of the Velcro finger adapters was further explored through their ability of generating repeatable and reproducible vibration measurements. Good repeatability was observed from the vibration transmissibility measured during three trials perfromed with bare hand fingers. In the reproducibility tests, the subjects were asked to remove and reinstall the finger adapters between the trials. The assessment results showed that the obtained vibration transmissibility measurements were reproducible within each subject. In order to enhance the understanding of fingers vibration, an investigation was conducted through measurements of vibration transmissibility of four different vibration reducing (VR) gloves at the middle phalanges of index and middle fingers using two Velcro finger adapters. Four male subjects participated in the measurements, which were conducted under the standardized vibration spectrum and the spectra of three different hand tools. Vibration transmissibility of the gloves were also measured at the palm using the standardized palm adapter. The frequency response functions (FRFs) of gloves at the index and middle fingers were utilized to estimate the vibration transmissibility of the gloves under different tool spectra. Only two gloves would be considered as AV gloves, although these showed fingers vibration amplification. The FRF method of estimating fingers vibration responses resulted in reliable prediction of the perfromance for different tools. Furthermore, 12 male subjects participated for assessment of integrated performance of 12 different VR gloves in terms of vibration transmission performance at the palm and fingers, as well as the effect of gloves on the grip strength preservation. The grip strength magnitude was measured using the cylindrical handle utilized in the vibration transmissibility measurements. The overall vibration transmissibility of the gloves at the fingers were obtained using the frequency weighting recommended in the standard and the reported fingers weighting. All the gloves attenuated fingers vibration in the 10–200 Hz frequency range, with exception of only two gloves. At greater frequencies (>200Hz), majority of the gloves amplified the middle finger transmitted vibration, while only a few gloves showed vibration amplification at the index finger. The effect of different frequency weightings on the vibration isolation performance of gloves at the fingers was only evident in the high frequency range (200–1250Hz). Only four gloves passed the standardized screening criteria despite their vibration amplification at the fingers. All the gloves resulted in reduced hand grip strength with only one exception.

Download or read book A Study of Vibration Response Characteristics of the Human Hand arm System written by Raghu Gurram and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Vibration Analysis of a Hand Held Percussion Tool Coupled with the Hand Arm System written by Shu Wang and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of Anti vibration Gloves in a Manufacturing Setting written by Andrew D. Forbes and published by . This book was released on 2013 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: While anti-vibration gloves are widespread as a form of reducing employee exposure to hand-arm vibration (HAV) there is concern about how effective they actually are in a real manufacturing environment with specific tools. Currently ISO 10819 is used to certify gloves as "anti-vibration"; however, the standard only tests a static position and force which may not accurately represent a gloves ability to reduce vibration exposure during specific tasks. The aims of this study are to examine 4 different types of gloves and see how effective they are at reducing vibration exposure in employees performing a specific workplace task. The first hypothesis tested is whether or not the gloves are different from the bare hand measurements. The null hypothesis is that there is no difference in vibration exposure when a glove is used. The second hypothesis evaluated is whether a difference can be observed between the gloves themselves. The null hypothesis is that there is no difference between the gloves. To determine the validity these two hypotheses, vibration exposure during a sanding task will be examined. The third hypothesis tested is whether the subjects' perception of vibration reduction with the gloves matches the actual measured results. The null hypothesis is that there is no difference between subject perception and the measured results. This was done with a questionnaire given to the subjects asking them to rate the perceived vibration and rank the gloves in order of most effective to least. A jitterbug-style orbital sander was mounted with a tri-axial accelerometer while the subject had another tri-axial accelerometer attached to the back of their hand and both were connected to the same data logger so that simultaneous measurements of both accelerometers could be taken. In a randomly assigned order the subject used each of the four gloves to take one minute samples from sanding both a vertical and a horizontal surface. The same was done for a barehanded measurement where the subject used no glove, also randomly assigned in the order. A ratio from the tool and hand samples was found for each glove to find the transmissibility factor. The gloved transmissibility factors were then compared to that subject's bare hand sample to find the corrected transmissibility of the glove. The results differed depending on which surface was used. On the horizontal surface there was not a significant difference between the gloves and the bare hand, but if the sample size would have been larger then there likely would have been. There was a significant difference between gloves; one of the gloves was found to amplify vibration exposure. On the vertical surface there was no difference between the gloves and the bare hand or between the gloves themselves. The subject rankings of the gloves did not closely resemble the actual results. According to this study, ISO 10819 may not accurately depict a glove's ability to mitigate vibration for specific tasks. The use of anti-vibration gloves may also be an ineffective way to try to reduce employee exposure to high levels of vibration.

Download or read book 14th International Conference on Hand Arm Vibration written by Deutsche Gesetzliche Unfallversicherung (DGUV) and published by DGUV/IFA. This book was released on 2019-05-30 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: In May 2019, the Institut für Arbeitsschutz der Deutschen Gesetzlichen Unfallversicherung (IFA) was hosting the 14th International Conference on Hand-Arm-Vibration. The event is organised every four years under the auspices of international expert bodies at changing places. It is aimed at all stakeholders in the subject, whether experts from the occupational safety and health and research communities or management personnel in the areas of manufacture and design. Mechanized manual work is often associated with exposure to vibration that may impact adversely upon the health and well-being of the affected individuals. Besides impairments to comfort and performance, harm to the hand-arm system, possibly permanent, must be prevented as a matter of priority. In a world of work that is becoming more and more complex, combined exposures are also becoming increasingly relevant. What influence does hand-arm vibration have in conjunction with noise or whole-body vibration? What contribution can be made by medicine, diagnostics, epidemiology, measurement technology and prevention to the identification and containment of risks, and better still, to their elimination? What is the role of international regulatory activity in this context? The 14th International Conference on Hand-Arm Vibration aimed to address these and many other questions concerning hand-arm vibration, and to find answers relevant to the field.

Download or read book Control of Hand Transmitted Vibration Through Development and Analysis of a Human Hand arm isolator Model written by Thomas Cherian and published by . This book was released on 1994 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Investigates hand-held power tool vibration transmitted to the operator's hand and arm. A vibration isolator, based upon the concept of energy flow divider, is proposed and analyzed for its potential benefits in reducing vibration.

Download or read book Lab and Field Based Approach for the Selection of Tool specific Vibration reducing Gloves written by Takafumi Asaki and published by . This book was released on 2014 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Measurement of Vibration Transmitted by Pneumatic Impact Tools and the Effectiveness of Anti vibration Gloves in Reducing the Hazardous Effects of Hand arm Vibration in the Petrochemical Industry written by Joe George and published by . This book was released on 2007 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of Hand Transmitted Vibration from a Hand held Rotary Power Tool written by Ahmed Youssef Elkaied and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of experiments are conducted to study the influence of mass unbalance, feed force and the presence of an autobalancer. The measured data are analyzed to derive the eight-hour energy equivalent vibration and the number of years of exposure that may cause vascular symptoms in 10% of the worker's population. The results suggest that exposure to hand-transmitted vibration under 510 gm-mm mass unbalance at a speed of 7500 rpm could cause vibration-induced white finger among 10% of the exposed population in approximately 2.8 years. The addition of autobalancer, however, could reduce the eight-hour energy equivalent value to nearly 20%. A preliminary attempt is made to derive a simplified model of coupled hand-grinder system. The model assumes rigid shaft-disc assembly, rigid tool body, linear bearing properties and the handles being attached rigidly to the tool body. A single-degree-of-freedom model of the hand and arm is also integrated along the y and z-axis of the basicentric axis system used in the study. The model results under varying degrees of mass-unbalance suggest that the magnitude of hand-transmitted vibration increases considerably with increasing mass-unbalance and angular speed. The results of the parametric study suggest that bearing damping does not influence the magnitude of transmitted vibration due to considerably higher natural frequency of the shaft-disc assembly. Increasing the damping properties of the hand-handle interface by introducing anti-vibration gloves or handle grips, however, could reduce the magnitude of transmitted vibration. From the results obtained from the analytical and experimental studies, it is concluded that the use of an automatic-balancer is vital to reduce the magnitudes of hand-transmitted vibration.

Download or read book The Effects of a Visco elastic Polymer Glove on Hand arm Vibration Muscle Activity and Comfort During Simulated Power Tool Use written by Ryan Alexander Shivpaul and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prolonged exposure to hand-transmitted vibration (HTV) as a result of power tools can lead to hand-arm vibration syndrome (HAVS). The effectiveness of anti-vibration (AV) gloves for the reduction of hand arm vibration remains unclear. The ability of a glove to attenuate vibration is largely influenced by the material properties and forearm muscle activity during tool use. Visco-elastic polymer (gel-based) and air-bladder AV gloves are the most common options, however the material properties of gel based options have seen little attention. The purpose of this study is to investigate vibration transmissibility, forearm muscle activity and subjective grip dexterity using a variety of gel-based compositions and designs. Participants completed six simulated hand-held power tool tasks. RMS vibration, grip force, muscle activity, and perceived levels of comfort, dexterity, onset of forearm muscle fatigue and impairment of tactile sensation were collected. Vibration attenuation was most effective along the Z axis, with properties such as decreased contact stiffness, as well as increased mass, elasticity and viscosity performing better. Further investigation of visco-elastic polymers using the ISO standardized protocol is needed.

Download or read book The Development of a Specification for a Simple Method to Determine Hand transmitted Vibration Exposure written by I. R. Price and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Glove Characteristics Influencing Control Manipulability written by James V. Bradley and published by . This book was released on 1957 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Method for the On site Recording and Subsequent Analysis of Hand transmitted Vibration written by P. M. Pitts and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Comparative Study of Head Arm Vibration Using Anti vibration Gloves and Insulated Handles Among Stone Grinding Workers written by Pornthip Yenjai and published by . This book was released on 2003 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling of Hand arm glove Vibration System and Testing and Evaluating of Antivibration Gloves written by Jianying Cui and published by . This book was released on 2001 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mechanical Vibration and Shock written by International Organization for Standardization and published by . This book was released on 1996 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: