Este trabalho apresenta um sistema para o processamento do sinal mioelétrico baseado em Redes Neurais e Wavelets. Com a aquisição dos sinais mioelétricos dos músculos do segmento mão-braço, é possível determinar diversos parâmetros para a caracterização dos movimentos executados. A Transformada Wavelets foi utilizada na etapa de segmentação do sinal e a rede neural artificial na caracterização do movimento executado. O sistema é constituído de um eletromiógrafo (EMG de 8 canais), placa de aquisição de dados e um computador responsável pelo processamento dos dados. Foram utilizado eletrodos de superfície posicionados em lugares estratégicos no segmento mão-braço. O experimento consiste em repetir movimentos do segmento mão-braço executados por um modelo virtual. Os movimentos avaliados, neste trabalho, são: contração da mão, extensão do punho, flexão do antebraço, flexão do punho, rotação do braço, rotação e flexão do antebraço, rotação do braço e contração da mão, extensão e flexão do punho, contração da mão e elevação do braço. Esses movimentos são apresentados ao sujeito em determinadas sequências através dos modelos virtuais desenvolvidos, permitindo assim, a padronização do movimento a ser executado pelo voluntário O sinal é adquirido através de uma placa de aquisição e processado. As etapas principais de processamento são: segmentação do sinal de interesse através da Wavelet Discreta, extração de características (r.m.s, variância, desvio padrão, sesgo, curtose ) e uso da Rede Neural para determinar o movimento executado final dos testes, foi verificado que o movimento contração da mão e elevação do braço apresentou uma taxa de acerto média de 75%; o movimento flexão do antebraço obteve 81% de acerto médio; a contração da mão obteve 33% de acerto médio, o movimento contração da mão 76% de acerto médio; o movimento de flexão do punho 100 % de acerto médio, rotação e flexão do antebraço 66% de acerto médio, extensão e flexão do punho um 16% de acerto médio, extensão do punho 83,3% de acerto médio, rotação do braço 16,7% de acerto médio. Rotação do braço e contração da mão 83,3% de acerto médio. / This work presents a neural-network myoelectric processing-based system. With the acquisition of myoelectric signals from the muscles of the hand-arm segment, it is possible to determine the parameters that characterize the executed movements. Therefore, in this work Artificial Neural Networks are implemented to recognize patterns in order to determine the executed movement. The system is constituted by an electromyography (8-channel EMG), a data acquisition board and a computer responsible for data processing. In this research an experimental system is developed to capture the myoelectric signals by means of an EMG and a data acquisition board. Surface electrodes located in strategic places in the hand-arm segment are used. The experiment consists of repeated movements of the hand-arm segment executed by a virtual model. The movements examined in this work are: hand contraction, fist extension, forearm flexion, fist flexion, arm rotation, forearm rotation and flexion, fist contraction and extension and arm elevation. Those movements are presented to a volunteer in a random way by means of the virtual models developed, permitting a standardization of the movements that are to be executed by the volunteer. In the last part it is verified that the hand-contraction movement and the arm-elevation movement present an accuracy rate average of 75%; the forearm-flexion movement reaches 81% of accuracy rate average, the hand-contraction movement with 33% of accuracy rate average, the hand-contraction movement with 76% of accuracy rate average, the fist-flexion movement reached a 100% in the accuracy rate average, the forearm rotation flexion movement with a 66% in the accuracy rate average, the fist extension and flexion movement reaches the 16% in the accuracy rate average and the fist-extension movement with a 83.3% of accuracy rate average.

Este trabalho apresenta um sistema para o processamento do sinal mioelétrico baseado em Redes Neurais e Wavelets. Com a aquisição dos sinais mioelétricos dos músculos do segmento mão-braço, é possível determinar diversos parâmetros para a caracterização dos movimentos executados. A Transformada Wavelets foi utilizada na etapa de segmentação do sinal e a rede neural artificial na caracterização do movimento executado. O sistema é constituído de um eletromiógrafo (EMG de 8 canais), placa de aquisição de dados e um computador responsável pelo processamento dos dados. Foram utilizado eletrodos de superfície posicionados em lugares estratégicos no segmento mão-braço. O experimento consiste em repetir movimentos do segmento mão-braço executados por um modelo virtual. Os movimentos avaliados, neste trabalho, são: contração da mão, extensão do punho, flexão do antebraço, flexão do punho, rotação do braço, rotação e flexão do antebraço, rotação do braço e contração da mão, extensão e flexão do punho, contração da mão e elevação do braço. Esses movimentos são apresentados ao sujeito em determinadas sequências através dos modelos virtuais desenvolvidos, permitindo assim, a padronização do movimento a ser executado pelo voluntário O sinal é adquirido através de uma placa de aquisição e processado. As etapas principais de processamento são: segmentação do sinal de interesse através da Wavelet Discreta, extração de características (r.m.s, variância, desvio padrão, sesgo, curtose ) e uso da Rede Neural para determinar o movimento executado final dos testes, foi verificado que o movimento contração da mão e elevação do braço apresentou uma taxa de acerto média de 75%; o movimento flexão do antebraço obteve 81% de acerto médio; a contração da mão obteve 33% de acerto médio, o movimento contração da mão 76% de acerto médio; o movimento de flexão do punho 100 % de acerto médio, rotação e flexão do antebraço 66% de acerto médio, extensão e flexão do punho um 16% de acerto médio, extensão do punho 83,3% de acerto médio, rotação do braço 16,7% de acerto médio. Rotação do braço e contração da mão 83,3% de acerto médio. / This work presents a neural-network myoelectric processing-based system. With the acquisition of myoelectric signals from the muscles of the hand-arm segment, it is possible to determine the parameters that characterize the executed movements. Therefore, in this work Artificial Neural Networks are implemented to recognize patterns in order to determine the executed movement. The system is constituted by an electromyography (8-channel EMG), a data acquisition board and a computer responsible for data processing. In this research an experimental system is developed to capture the myoelectric signals by means of an EMG and a data acquisition board. Surface electrodes located in strategic places in the hand-arm segment are used. The experiment consists of repeated movements of the hand-arm segment executed by a virtual model. The movements examined in this work are: hand contraction, fist extension, forearm flexion, fist flexion, arm rotation, forearm rotation and flexion, fist contraction and extension and arm elevation. Those movements are presented to a volunteer in a random way by means of the virtual models developed, permitting a standardization of the movements that are to be executed by the volunteer. In the last part it is verified that the hand-contraction movement and the arm-elevation movement present an accuracy rate average of 75%; the forearm-flexion movement reaches 81% of accuracy rate average, the hand-contraction movement with 33% of accuracy rate average, the hand-contraction movement with 76% of accuracy rate average, the fist-flexion movement reached a 100% in the accuracy rate average, the forearm rotation flexion movement with a 66% in the accuracy rate average, the fist extension and flexion movement reaches the 16% in the accuracy rate average and the fist-extension movement with a 83.3% of accuracy rate average.

Hand Arm Vibration Syndrome (HAVS) is a collective term for the symptoms arising from the prolonged use of vibrating hand tools. An investigation into the literature on available screening tools for HAVS was conducted. A screening tool is used for the quick identification of certain symptoms without a full medical check up, and is for use by mine medical personnel for the determination of workers with HAVS symptoms and those without. Twenty-two non-exposed volunteers were tested with the screening tools and forty-two rock drill operators. Only the rock drill operators had a medical examination and standardised tests for HAVS diagnoses, to determine their HAVS diagnosis and severity. This diagnosis was used as the standard for the evaluation, of existing screening tools and for developed screening tool, sensitivity for the detection of HAVS symptoms. The screening tools chosen were a traditional tuning fork, a similar tuning fork but mounted into a box with a set excitation unit and a two-point discriminator set a 3mm, 6mm, and 10mm apart. The results showed that a screening questionnaire that specifically focuses on the symptoms of HAVS has better sensitivity and specificity to identify cases. A two-point discriminator with variable distance points, where patients have to distinguish between one pin prick and two, was able to identify HAVS cases when the distance was set at 3mm. However, the sensitivity of the two-point discriminator was lower than the sensitivity of the questionnaire. / Dissertation (MSc)--University of Pretoria, 2007. / Industrial and Systems Engineering / Unrestricted

Die Gesundheit von Beschäftigten in Unternehmen wird unter dem Aspekt einer sich verändernden Altersstruktur und sich schneller wandelnden Arbeitsbedingungen zunehmend an innerbetrieblicher Bedeutung gewinnen. Sie ist einer der Schlüssel zur Erhaltung und Förderung der Arbeitsbewältigungsfähigkeit der Mitarbeiter und damit Arbeitsfähigkeit sowie die Leistungsbereitschaft auf der Lebensarbeitszeitachse zu erhalten und somit Kontinuität in einer manuellen Produktion zu erzeugen. Die vorliegende Masterarbeit beschäftigt sich mit der Analyse eines Montagearbeitsplatzes in einem mittelständischen Betrieb, hinsichtlich ergonomischer Belastungsfaktoren. Bei der analysierten Tätigkeit steht die physische Belastung aus Körperzwangshaltung und des Hand-Arm-Schulter Systems im Mittelpunkt, da dieses die wesentlichen Belastungsfaktoren sind. Ein weiterer Aspekt war, dass die hier untersuchte Arbeitsaufgabe eine sehr gute Ausgangsbasis schafft um Rückschlüsse auf die Fertigungs- und Montagebedingungen fast aller anderen Produkte zu ziehen. Die Arbeit gibt somit nicht nur Auskunft über die aktuelle ergonomische Belastung bei der Produktion des Centerwave 6000 und ihrer Verbesserungsmaßnahmen, sondern eröffnet auch die Perspektive einen generellen Gesundheitsgewinn zu erzielen, der auf der Minimierung von vergleichbaren ergonomischen Risikofaktoren in der gesamten Fertigung beruht.

No description available.

Vibracijos žalingam poveikiui į žmogaus organizmą lemia daug įvairių veiksnių. Tyrimai šioje srityje koncentruojasi į mašinos virpesių energijos dydį ir jos mažinimo galimybes, tačiau aktualu ir žmogaus-mašinos analizavimas kaip bendros sistemos. Tokios sistemos virpesių energijos perdavimas į žmogaus kūną priklauso ir nuo sistemos standumo savybių, kurias galima apibūdinti kontaktinėmis jėgomis tarp mašinos ir žmogaus kūno dalies. Tokių tyrimų Lietuvoje nebuvo atlikta, o užsienio autorių tyrimai negausūs, todėl tyrimas yra labai aktualus. Tiriamajame darbe analizuojama kitų autorių tyrimų medžiaga apie vibracijos poveikį žmogui, sudaryta tyrimų metodika ir atlikti tyrimai, kaip nešiojamųjų ar rankomis valdomų mašinų įrankių jėgos pasiskirsto rankos plaštakoje ir kokią įtaką per rankas veikiančios vibracijos perdavimui turi rankos ir darbo priemonės sąlyčio jėgos. Nustatyta, kad didėjant sąlyčio jėgoms tarp vibruojančios darbo priemonės (įrankio) ir rankos nuo 3 N iki 29 N bendroji vibracijos vertė veikianti operatoriaus ranką didėjo nuo 2,7 m/s2 iki 3,7 m/s2. / Hazardous affects of vibration against a human’s organism are caused by various factors. Researches in this field are concentrated into the energy size of machine vibration and possibilities to decrease it; however, analysis of a human-machine as a general system is also relevant. Transfer of vibration energy by such system into a human’s body depends on properties of system rigidity, which may be described as contact forces between a machine and a human’s body part. Such researches were not carried out in Lithuania and the studies of foreign authors are not numerous, thus such analysis is very relevant. The study thesis analyses research materials by other authors on vibration impact on humans. There were developed research methods and performed tests on how strengths of mobile and manually operated tools distribute over the hand and what impact hand - tool contact strengths have on transfer of vibration acting through hands. It was determined that increase in contact strength between a vibrating tool and a hand from 3 N to 29 N total vibration value on the operator’s hand increase from 2,7 m/s2 to 3,7 m/s2.

No description available.

This report presents a Master of Science Thesis, conducted at the Royal Institute of Technology, within Industrial Design Engineering, in collaboration with the privately owned healthcare company Praktikertjänst AB. The purpose of this project was to investigate the distribution of injuries and issues in the hand-/arm extremities among dentistry personnel, as well as explore the possibility to prevent these to emerge. Through literature studies, field visits and empirical methods, valuable insights have been obtained. These were processed and resulted in recommendations for future product development including suggestions of solutions, and a checklist for clinics which they can use to prevent strain issues from occurring. The result shows that work-related strain issues in the hand-/arm extremities exist to a large extent among dentistry personnel. Most dentistry personnel with hand-/arm problems experience pain in their fingers and wrist on their right-hand side. Then, it is most common with strain injuries in the fingers and wrist, where the three most specified injuries were thumb arthritis, carpal tunnel syndrome and lateral epicondylitis. Moreover, the most common symptoms were cold hands, numbness, and impaired grip. However, these symptoms were not connected to a specific injury. The underlying causes of these issues are many but could be reduced by ergonomic product development and human centered design. Furthermore, it would be interesting to examine the impact of vibrations, since symptoms of vibration syndromes can be seen, and few respondents have specified a diagnosis. Also, the result shows that there are presumably unrecorded cases in national statistics considering work related injuries. Whether the result can be generalized for the whole dental care sector or not is difficult to determine, since most of the material was gathered from the private sector. Therefore, it would be of great interest to carry out a similar study within the regional dentistry. / Denna rapport redovisar ett masterexamensarbete utfört på Kungliga Tekniska Högskolan, inom Teknisk Design, i samarbete med det privata vårdbolaget Praktikertjänst AB. Syftet med projektet var att undersöka utbredningen av skador och problem i hand-/armregionen hos tandvårdspersonal, samt utforska möjligheten att förebygga uppkomsten av dessa besvär. Med hjälp av litteraturstudier, studiebesök och empiriska metoder har värdefulla insikter erhållits. Dessa har sedan bearbetats och resulterat i rekommendationer för framtida produktutveckling innehållande lösningsförslag, samt en checklista för kliniker som kan hjälpa till att förebygga belastningsbesvär. Resultatet visar att det i stor utsträckning förekommer arbetsrelaterade belastningsbesvär i hand-/armregionen hos tandvårdspersonal. För de med hand-/armproblem är smärta vanligast att uppleva i fingrar och handled på höger sida. Sedan förekommer flest belastningsskador i fingrar och handled, där de tre mest specificerade skadorna är artros i tummen, karpaltunnelsyndrom och tennisarmbåge. Vidare är de vanligaste symtomen kalla händer, domningar och försämrad gripkraft. Dessa symtom i hand/arm är dock inte kopplade till någon specifik skada. De bakomliggande orsakerna till dessa besvär är många, men skulle kunna reduceras med hjälp av ergonomisk produktutveckling och människocentrerad design. Det vore intressant att närmare undersöka hur vibrationer påverkar dessa besvär, då symtom till vibrationsskador existerar, men få har specificerat en diagnos. Vidare tyder resultatet på att det troligen är ett stort mörkertal i nationell statistik angående arbetsskador. Om resultatet går att generalisera för hela tandvården är svårt att avgöra, eftersom övervägande mängd material har samlats in från privat sektor. Därför vore det intressant att utföra en liknande studie inom Folktandvården.

In many occupations, exposure to hand-transmitted vibration (HTV) over a prolonged period causes various disorders involving the vascular, neural and musculoskeletal systems, collectively known as the hand-arm vibration syndrome (HAVS). It is a complex and potentially disabling chronic disorder of the upper extremities, especially of the hands. Numbness, tingling, reduced tactile discrimination, and impaired manipulative dexterity are often reported by workers exposed to HTV. The precise pathophysiological mechanism responsible for vascular injuries in HAVS has not yet been fully clarified; it seems to be multifactorial and highly complex. Interaction of neural signals, hormones, mediators and changes in the blood vessel itself appear to contribute to the development of such vascular injuries. This study aims to assess the risk of the hand-transmitted vibration exposure during pneumatic impact wrench operation in a rock drill repair and maintenance workshop at a South African platinum mine. A total of 8 workers working on a day to day basis with impact wrenches were available for this study. For each of the workers a control (not exposed to vibration) was selected on the basis of gender, ethnic group, smoking habits, age and body mass index (BMI). Grip force, dexterity and hand-eye co-ordination were tested on the workers and control group before and after work. Finger systolic blood pressure (FSBP) was also measured after cold provocation of the worker and control groups. Results have shown astatistically significant difference between the two groups with respect coordination, dexterity and FSBP after cold provocation. Vibration measurements shows three workers had values above the suggested ELV of 5 m/s² for an eight hour A (8) workday. With regards to dexterity, workers were capable to manipulate small objects better with their dominant right (vibration exposed) hand after work than before work. In contrast, it seems that the number of pegs correctly inserted by the controls is not uniformly affected by their 8 hour workday. The worker group showed a greater grip force than that of the control group, both before and after work.There was a statistically significant difference between the control and worker group with respect to the number of mistakes during the mirror trace and the time to complete this test only for the right hand. The difference in FSBP after cold provocation between the control and worker group observed is of medium importance when compared with effect sizes, however, there was no statistical significant difference. In this study, it was very difficult to make valid conclusions due to the limitations of a small sample size. A longitudinal study should be conducted preferably using newly appointed workers with no prior exposure to vibration and a sufficient control group to eliminate the effect other confounding variables such as general working conditions. / Thesis (MSc (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2013.

In many occupations, exposure to hand-transmitted vibration (HTV) over a prolonged period causes various disorders involving the vascular, neural and musculoskeletal systems, collectively known as the hand-arm vibration syndrome (HAVS). It is a complex and potentially disabling chronic disorder of the upper extremities, especially of the hands. Numbness, tingling, reduced tactile discrimination, and impaired manipulative dexterity are often reported by workers exposed to HTV. The precise pathophysiological mechanism responsible for vascular injuries in HAVS has not yet been fully clarified; it seems to be multifactorial and highly complex. Interaction of neural signals, hormones, mediators and changes in the blood vessel itself appear to contribute to the development of such vascular injuries. This study aims to assess the risk of the hand-transmitted vibration exposure during pneumatic impact wrench operation in a rock drill repair and maintenance workshop at a South African platinum mine. A total of 8 workers working on a day to day basis with impact wrenches were available for this study. For each of the workers a control (not exposed to vibration) was selected on the basis of gender, ethnic group, smoking habits, age and body mass index (BMI). Grip force, dexterity and hand-eye co-ordination were tested on the workers and control group before and after work. Finger systolic blood pressure (FSBP) was also measured after cold provocation of the worker and control groups. Results have shown astatistically significant difference between the two groups with respect coordination, dexterity and FSBP after cold provocation. Vibration measurements shows three workers had values above the suggested ELV of 5 m/s² for an eight hour A (8) workday. With regards to dexterity, workers were capable to manipulate small objects better with their dominant right (vibration exposed) hand after work than before work. In contrast, it seems that the number of pegs correctly inserted by the controls is not uniformly affected by their 8 hour workday. The worker group showed a greater grip force than that of the control group, both before and after work.There was a statistically significant difference between the control and worker group with respect to the number of mistakes during the mirror trace and the time to complete this test only for the right hand. The difference in FSBP after cold provocation between the control and worker group observed is of medium importance when compared with effect sizes, however, there was no statistical significant difference. In this study, it was very difficult to make valid conclusions due to the limitations of a small sample size. A longitudinal study should be conducted preferably using newly appointed workers with no prior exposure to vibration and a sufficient control group to eliminate the effect other confounding variables such as general working conditions. / Thesis (MSc (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2013.