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 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 Ergonomic Impact of Glove Use in a Coating Removal Task written by Ian C. Rybczynski and published by . This book was released on 2002 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Workers who are in maintenance and repair occupations are routinely exposed to several musculoskeletal disorder risk factors. The purpose of this study was to investigate the effects of glove use during a coating removal task, which is a common maintenance and repair task. Nine healthy subjects (5 male and 4 female) participated in this study. The subjects removed identical painted sections using either a metal finishing (nylon) pad or a plastic scraper, while wearing one of thirteen glove conditions. The order of the glove conditions was randomized for each subject. Force exertions were monitored along with EMO readings from the finger flexors, finger extensors, biceps, and triceps. The results showed that there were significant increases in force outputs and muscle activities when using gloves as compared to a barehanded condition. There was some evidence that indicated glove material and glove thickness are important characteristics in these observations. These findings may have implications for a worker's musculoskeletal disorders risk and for glove selection guidelines in industry.
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 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 Hand arm Vibration written by P. L. Pelmear and published by Van Nostrand Reinhold Company. This book was released on 1992 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: According to estimates, hand-arm vibration jeopardizes the health and future employability of at least two million workers in the USA alone. A broad-based approach to the problem is needed because an accurate evaluation of the health effects of hand-arm vibration involves engineering, medicine, physiology, epidemiology, mathematics and statistics.
Download or read book Quantifying Hand arm Vibration Transmissibility During Impact Wrench Use in Fatiguing Tasks written by and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction: Prolonged use of hand-held vibratory power tools is a risk factor for vascular, neural, and musculoskeletal disorders, largely dependent on the magnitude and frequency content of vibration generated by the tool. However, there is a need to better understand the effects of physical risk factors on hand transmitted vibration, including the combined effects of hand-arm postures and repetitive efforts that generate neuromuscular fatigue over time. Methods: Ten healthy males performed 4 sets of repetitively tightening20 bolts onto nuts using a pneumatic impact wrench with their dominant hand. The task was performed in two postures (arm by side versus arm above shoulder) on two randomized testing days. Triaxial accelerometry measured vibration at the tool’s handle and the participant’s dorsal hand (3rd metacarpal) at 2500 Hz. Vibration transmissibility from the tool to the hand was calculated as a function of their respective power spectral densities. Maximum grip force was also measured before and after each repeated set to assess fatigue development. Surface electromyography further quantified fatigue development during the grip task of forearm musculature. Both grip force and electromyography were collected at4000 Hz. Results: Despite lower magnitude of the vector summated frequency-weighted root-mean-squared vibration at the tool in the arm by side versus above shoulder posture(arm by side: 4.7 ± 0.17 m/s2; above shoulder: 5.15 ± 0.15 m/s2; p=0.037), the effects were reversed when considering tool-to-hand transmissibility. Specifically, I observed markedly higher hand transmitted vibration in the arm-by side posture, especially for the yh-axis aligned with the tool’s handle (arm by side: 2.51 ± 0.3; above shoulder: 1.31 ± 0.1; p.001).However, across all axes, repeated set number (1–4) did not influence root-mean-squared acceleration at the tool (p0.61) or tool-to-hand transmissibility (p>0.39). A significant interaction between hand-arm posture and pre-post vibratory tool use on the standardized grip strength task revealed reduced grip force immediately following vibratory tool use, with more pronounced pre-post reductions in the above shoulder posture compared to the arm by side posture (p
Download or read book A Study of Hand handle Interactions and Hand arm Biodynamic Response to Vibration written by Yasser Saed Aldien and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of Analytical Models to Study Musculoskeletal and Vascular Damage Leading to Hand arm Vibration Syndrome written by Shrikant P. Pattnaik and published by . This book was released on 2011 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prolonged exposure to tool vibration causes vascular, neurological and musculoskeletal abnormalities in hand-arm system, which is collectively known as hand-arm vibration syndrome (HAVS). HAVS is a major musculoskeletal disorder (MSD) affecting large numbers of construction workers and miners. One of the major symptoms of HAVS is vibration white finger (VWF) caused by exaggerated vasoconstriction of the arteries and skin arterioles. A significant number of construction workers, miners and even dentists are affected by HAVS. The precise mechanism or pathogenesis of the syndrome still remains unclear, and there is a need for better understanding of various biodynamic responses induced by vibration. Accurate analysis of hand-arm vibration response is very difficult due to the complexity of the hand-arm structure such as redundancy of the musculo-tendon unit, active participation from central nervous system, inherent non-linearity and heavy damping effect. Three fundamental modeling methods are developed in this study to understand the cause of musculoskeletal responses and vascular system responses of the hand-arm system. The first model is a musculoskeletal kinematic model developed by adopting a modified Hill's model to describe the behavior of the muscle and tendon. At first, the force in each muscle necessary to generate the grip force is determined by a quadratic optimization process. Using the force determined, the activation level of the muscle is found by assuming that the muscle-tendon undergoes an isometric contraction during the gripping. With the activation level known, the muscle-tendon system is simplified by a set of spring-mass-damper based on the assumption that the muscle response to the vibration is passive. From dynamic analysis it is shown that smaller intrinsic muscles are vulnerable to high frequency vibrations even if the overall response of the hand-arm is small. The second model addresses vasospasm in finger artery caused by vibration, therefore a small artery is modeled as a fluid filled elastic tube whose diameter changes along the axial direction. Equations of motion are developed by considering interactions between the fluid, artery wall and soft-tissue bed. It is shown that the artery system shows a spatial resonance which responds with the highest amplitude at the location determined by the vibration frequency. This implies that a long-term use of one type of tool will induce high-level stresses at a few identical locations of the artery that correspond to the major frequency components of the tool. Hardening and deterioration of the artery at these locations may be a possible cause of VWF. The wave model is applied also to arteries of larger size such as coronary arteries, employing the equivalent circuit representation. The third model is a flexible finite element based model of human index finger, which is created with most anatomical substructures, taking into account nonlinear tissue properties to study localized stress and strain pattern under dynamic loading. High strain and energy absorption can cause local tissue and nerve damage leading to numbness. All these unique modeling techniques provide much needed methodology to understand various aspects of HAVS and its precursor.
Download or read book Semi analytical Analysis of Hand arm Vibration and Bench top Fluid Flow Test to Understand Vibration Effects on Vascular Disorder written by Robin DeJager-Kennedy and published by . This book was released on 2010 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hand and Arm Vibration Syndrome (HAVS) collectively refers to various hand-arm injuries due prolonged exposure of hand and arm to vibrations. Due to the complexity of the hand-arm system, exact pathology of the HAVS is not well-understood to this date. Two separate studies are conducted in this research to develop basic tools to study HAVS. As the first study, a semi-analytical method to calculate the hand-arm response to the tool vibration is developed. The method is a two-step procedure. In the first step, the excitation force due to tool operation is estimated experimentally from the acceleration measured from a free-suspended tool operating in no-load condition. In the second step, the response of the tool is calculated from a theoretical model of the hand-arm system using the estimated force. It is demonstrated that the method can be used to assess the quality of a hand-arm simulation model using several lumped parameter models and a rigid beam model. The method can be used with any type of hand-arm model to obtain basic information to further study the issue of HAVS. The method also can be applied to estimate the force transmitted from the tool to the hand, which may be used as the basic data for further detailed analysis. The second study is intended to develop an experimental method to demonstrate that vibration influences the flow rate of vascular circulation. A closed-loop flow test system with a small interchangeable test section is constructed for an in-vitro test of vascular circulation. Vibration is applied to the various test sections; however no significant vibration effect on the flow through the test section was observed. Necessary future studies are identified based on the results from this research.
Download or read book The Effect of Different Working Posture and Grip Force on Hand Arm Muscle Activity Using Vibration Tool written by Kim Ting Siow and published by . This book was released on 2009 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Wearable Robots written by José L. Pons and published by John Wiley & Sons. This book was released on 2008-04-15 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: A wearable robot is a mechatronic system that is designed around the shape and function of the human body, with segments and joints corresponding to those of the person it is externally coupled with. Teleoperation and power amplification were the first applications, but after recent technological advances the range of application fields has widened. Increasing recognition from the scientific community means that this technology is now employed in telemanipulation, man-amplification, neuromotor control research and rehabilitation, and to assist with impaired human motor control. Logical in structure and original in its global orientation, this volume gives a full overview of wearable robotics, providing the reader with a complete understanding of the key applications and technologies suitable for its development. The main topics are demonstrated through two detailed case studies; one on a lower limb active orthosis for a human leg, and one on a wearable robot that suppresses upper limb tremor. These examples highlight the difficulties and potentialities in this area of technology, illustrating how design decisions should be made based on these. As well as discussing the cognitive interaction between human and robot, this comprehensive text also covers: the mechanics of the wearable robot and it’s biomechanical interaction with the user, including state-of-the-art technologies that enable sensory and motor interaction between human (biological) and wearable artificial (mechatronic) systems; the basis for bioinspiration and biomimetism, general rules for the development of biologically-inspired designs, and how these could serve recursively as biological models to explain biological systems; the study on the development of networks for wearable robotics. Wearable Robotics: Biomechatronic Exoskeletons will appeal to lecturers, senior undergraduate students, postgraduates and other researchers of medical, electrical and bio engineering who are interested in the area of assistive robotics. Active system developers in this sector of the engineering industry will also find it an informative and welcome resource.
Download or read book Biomechanics in Ergonomics written by Shrawan Kumar and published by CRC Press. This book was released on 2007-12-07 with total page 744 pages. Available in PDF, EPUB and Kindle. Book excerpt: Safety or comfort? Can you truly have one without the other? Is it feasible to have both? Although by no means the only factor, a deep understanding of biomechanics plays a leading role in the design of work and workplaces that are both pain and injury free. Standing firmly on the foundation built by the previous edition, the second edition of Biom
Download or read book Biotribology written by Duncan Dowson and published by Wiley. This book was released on 2019-12-04 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Biomaterial Properties written by William Murphy and published by Springer. This book was released on 2016-06-11 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides tabular and text data relating to normal and diseased tissue materials and materials used in medical devices. Comprehensive and practical for students, researchers, engineers, and practicing physicians who use implants, this book considers the materials aspects of both implantable materials and natural tissues and fluids. Examples of materials and topics covered include titanium, elastomers, degradable biomaterials, composites, scaffold materials for tissue engineering, dental implants, sterilization effects on material properties, metallic alloys, and much more. Each chapter author considers the intrinsic and interactive properties of biomaterials, as well as their appropriate applications and historical contexts. Now in an updated second edition, this book also contains two new chapters on the cornea and on vocal folds, as well as updated insights, data, and citations for several chapters.
Download or read book Handbook of Smart Textiles written by Xiaoming Tao and published by Springer. This book was released on 2015-10-14 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The “Handbook of Smart Textiles” aims to provide a comprehensive overview in the field of smart textile describing the state of the art in the research sector as well as the well-established techniques applied in industries. The handbook is planned to cover from fundamental theories, experimental techniques, characterization methods, as well as real applications with successful commercialized examples. The book is structured in a way in which it is appropriate for graduate students, PhD candidates, and professionals in diverse scientific and engineering communities devoted to relevant fields, including textile engineering, chemistry, bioengineering, material engineering, mechanical engineering, electrical engineering. The book will also provide a solid reference for industrial players who look for innovative technologies as well as environmental, safety concerns for the development of smart textile related products.
