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Sample records for hand transmitted vibration

  1. Reduction in finger blood flow induced by hand-transmitted vibration: effect of hand elevation.

    PubMed

    Ye, Ying; Mauro, Marcella; Bovenzi, Massimo; Griffin, Michael J

    2015-10-01

    This study investigated the effect of hand elevation on reductions in finger blood flow (FBF) induced by hand-transmitted vibration. Fourteen males attended six sessions on six separate days, with a control sessions and a vibration session (125-Hz vibration at 44 ms(-2) rms) with the right hand supported at each of three elevations: 20 cm below heart level (HL), at HL, and 20 cm above HL. Finger blood flow on the left and right hand was measured every 30 s during each 25-min session comprised of five periods: (1) no force and no vibration (5 min), (2) 2-N force and no vibration (5 min), (3) 2-N force and vibration (5 min), (4) 2-N force and no vibration (5 min), and (5) no force and no vibration (5 min). Without vibration, FBF decreased with increasing elevation of the hand. During vibration of the right hand, FBF reduced on both hands. With elevation of the right hand, the percentage reduction in FBF due to vibration (relative to FBF on the same finger at the same elevation before exposure to vibration) was similar on the middle and little fingers of both hands. After cessation of vibration, there was delayed return of FBF with all three hand heights. Vibration of one hand reduces FBF on both exposed and unexposed hands, with the reduction dependent on the elevation of the hand. The mechanisms responsible for vibration-induced reductions in FBF seem to reduce blood flow as a percentage of the blood flow without vibration. Tasks requiring the elevation of the hands will be associated with lower FBF, and the FBF will be reduced further if there is exposure to hand-transmitted vibration.

  2. Hand-transmitted vibration and biodynamic response of the human hand-arm: a critical review.

    PubMed

    Dong, R G; Rakheja, S; Schopper, A W; Han, B; Smutz, W P

    2001-01-01

    Hand-arm vibration syndrome (HAVS) has been associated with prolonged exposure to vibration transmitted to the human hand-arm system from hand-held power tools, vibrating machines, or hand-held vibrating workpieces. The biodynamic response of the human hand and arm to hand transmitted vibration (HTV) forms an essential basis for effective evaluations of exposures, vibration-attenuation mechanisms, and potential injury mechanisms. The biodynamic response to HTV and its relationship to HAVS are critically reviewed and discussed to highlight the advances and the need for further research. In view of its strong dependence on the nature of HTV and the lack of general agreement on the characteristics of HTV, the reported studies are first reviewed to enhance an understanding of HTV and related issues. The characteristics of HTV and relevant unresolved issues are discussed on the basis of measured data, proposed standards, and measurement methods, while the need for further developments in measurement systems is emphasized. The studies on biodynamic response and their findings are grouped into four categories based on the methodology used and the objective. These include studies on (1) through-the-hand-arm response, expressed in terms of vibration transmissibility; (2) to-the-hand response, expressed in terms of the force-motion relationship of the hand-arm system; (3) to-the-hand biodynamic response function, expressed in terms of vibration energy absorption; and (4) computer modeling of the biodynamic response characteristics.

  3. Dupuytren's contracture and occupational exposure to hand-transmitted vibration

    PubMed Central

    Palmer, Keith T; D'Angelo, Stefania; Syddall, Holly; Griffin, Michael J; Cooper, Cyrus; Coggon, David

    2014-01-01

    Aims The relation between Dupuytren's contracture and occupational exposure to hand-transmitted vibration (HTV) has frequently been debated. We explored associations in a representative national sample of workers with well-characterised exposure to HTV. Methods We mailed a questionnaire to 21 201 subjects aged 16–64 years, selected at random from the age-sex registers of 34 general practices in Great Britain and to 993 subjects chosen randomly from military pay records, asking about occupational exposure to 39 sources of HTV and about fixed flexion contracture of the little or ring finger. Analysis was restricted to men at work in the previous week. Estimates were made of average daily vibration dose (A(8) root mean squared velocity (rms)) over that week. Associations with Dupuytren's contracture were estimated by Poisson regression, for lifetime exposure to HTV and for exposures in the past week >A(8) of 2.8 ms−2 rms. Estimates of relative risk (prevalence ratio (PR)) were adjusted for age, smoking status, social class and certain manual activities at work. Results In all 4969 eligible male respondents supplied full information on the study variables. These included 72 men with Dupuytren's contracture, 2287 with occupational exposure to HTV and 409 with A(8)>2.8 ms−2 in the past week. PRs for occupational exposure to HTV were elevated 1.5-fold. For men with an A(8)>2.8 ms−2 in the past week, the adjusted PR was 2.85 (95% CI 1.37 to 5.97). Conclusions Our findings suggest that risk of Dupuytren's contracture is more than doubled in men with high levels of weekly exposure to HTV. PMID:24449599

  4. Frequency-dependence of psychophysical and physiological responses to hand-transmitted vibration.

    PubMed

    Griffin, Michael J

    2012-01-01

    This invited paper reviews experimental studies of the frequency-dependence of absolute thresholds for the perception of vibration, equivalent comfort contours, temporary changes in sensation caused by vibration, and reductions in finger blood flow caused by hand-transmitted vibration. Absolute thresholds depend on the contact conditions but for a typical hand grip the thresholds show greatest sensitivity to acceleration around 125 Hz. The frequency-dependence of discomfort caused by hand-transmitted vibration depends on vibration magnitude: similar to absolute thresholds at low magnitudes, but the discomfort at higher magnitudes is similar when the vibration velocity is similar (at frequencies between about 16 and 400 Hz). Hand-transmitted vibration induces temporary elevations in vibrotactile thresholds that reflect the sensory mechanisms excited by the vibration and are therefore highly dependent on the frequency of vibration. Hand-transmitted vibration reduces finger blood flow during and after exposure; when the vibration velocity is similar at all frequencies there is more vasoconstriction at frequencies greater than 63 Hz than at lower frequencies. A single frequency weighting cannot provide a good indication of how all effects of hand-transmitted vibration depend on vibration frequency. Furthermore, a single frequency weighting provides only an approximate indication of any single response, because many factors influence the frequency-dependence of responses to hand-transmitted vibration, including the magnitude of vibration, contact conditions, and individual differences. Although the frequency weighting in current standards extends from 8 to 1,000 Hz, frequencies greater than 400 Hz rarely increase the weighted value on tools and there is currently little psychophysical or physiological evidence of their effects.

  5. Dose-response relationship between hand-transmitted vibration and hand-arm vibration syndrome in a tropical environment.

    PubMed

    Su, Anselm Ting; Maeda, Setsuo; Fukumoto, Jin; Darus, Azlan; Hoe, Victor C W; Miyai, Nobuyuki; Isahak, Marzuki; Takemura, Shigeki; Bulgiba, Awang; Yoshimasu, Kouichi; Miyashita, Kazuhisa

    2013-07-01

    The dose-response relationship for hand-transmitted vibration has been investigated extensively in temperate environments. Since the clinical features of hand-arm vibration syndrome (HAVS) differ between the temperate and tropical environment, we conducted this study to investigate the dose-response relationship of HAVS in a tropical environment. A total of 173 male construction, forestry and automobile manufacturing plant workers in Malaysia were recruited into this study between August 2011 and 2012. The participants were interviewed for history of vibration exposure and HAVS symptoms, followed by hand functions evaluation and vibration measurement. Three types of vibration doses-lifetime vibration dose (LVD), total operating time (TOT) and cumulative exposure index (CEI)-were calculated and its log values were regressed against the symptoms of HAVS. The correlation between each vibration exposure dose and the hand function evaluation results was obtained. The adjusted prevalence ratio for finger tingling and numbness was 3.34 (95% CI 1.27 to 8.98) for subjects with lnLVD≥20 ln m(2) s(-4) against those <16 ln m(2) s(-4). Similar dose-response pattern was found for CEI but not for TOT. No subject reported white finger. The prevalence of finger coldness did not increase with any of the vibration doses. Vibrotactile perception thresholds correlated moderately with lnLVD and lnCEI. The dose-response relationship of HAVS in a tropical environment is valid for finger tingling and numbness. The LVD and CEI are more useful than TOT when evaluating the dose-response pattern of a heterogeneous group of vibratory tools workers.

  6. Evaluating the effectiveness of gloves in reducing the hazards of hand- transmitted vibration

    PubMed Central

    Griffin, M. J.

    1998-01-01

    OBJECTIVES: A method of evaluating the effectiveness of gloves in reducing the hazards of hand-transmitted vibration is proposed. METHOD: The glove isolation effectiveness was calculated from: (a) the measured transmissibility of a glove, (b) the vibration spectrum on the handle of a specific tool (or class of tools), and (c) the frequency weighting indicating the degree to which different frequencies of vibration cause injury. With previously reported tool vibration spectra and glove transmissibilities (from 10-1000 Hz), the method was used to test 10 gloves with 20 different powered tools. RESULTS: The frequency weighting for hand-transmitted vibration advocated in British standard 6842 (1987) and international standard 5349 (1986) greatly influences the apparent isolation effectiveness of gloves. With the frequency weighting, the gloves had little effect on the transmission of vibration to the hand from most of the tools. Only for two or three tools (those dominated by high frequency vibration) did any glove provide useful attenuation. Without the frequency weighting, some gloves showed useful attenuation of the vibration on most powered tools. CONCLUSIONS: In view of the uncertain effect of the vibration frequency in the causation of disorders from hand-transmitted vibration, it is provisionally suggested that the wearing of a glove by the user of a particular vibratory tool could be encouraged if the glove reduces the transmission of vibration when it is evaluated without the frequency weighting and does not increase the vibration when it is evaluated with the frequency weighting. A current international standard for the measurement and evaluation of the vibration transmitted by gloves can classify a glove as an antivibration glove when it provides no useful attenuation of vibration, whereas a glove providing useful attenuation of vibration on a specific tool can fail the test.   PMID:9764112

  7. Evaluating the effectiveness of gloves in reducing the hazards of hand-transmitted vibration.

    PubMed

    Griffin, M J

    1998-05-01

    A method of evaluating the effectiveness of gloves in reducing the hazards of hand-transmitted vibration is proposed. The glove isolation effectiveness was calculated from: (a) the measured transmissibility of a glove, (b) the vibration spectrum on the handle of a specific tool (or class of tools), and (c) the frequency weighting indicating the degree to which different frequencies of vibration cause injury. With previously reported tool vibration spectra and glove transmissibilities (from 10-1000 Hz), the method was used to test 10 gloves with 20 different powered tools. The frequency weighting for hand-transmitted vibration advocated in British standard 6842 (1987) and international standard 5349 (1986) greatly influences the apparent isolation effectiveness of gloves. With the frequency weighting, the gloves had little effect on the transmission of vibration to the hand from most of the tools. Only for two or three tools (those dominated by high frequency vibration) did any glove provide useful attenuation. Without the frequency weighting, some gloves showed useful attenuation of the vibration on most powered tools. In view of the uncertain effect of the vibration frequency in the causation of disorders from hand-transmitted vibration, it is provisionally suggested that the wearing of a glove by the user of a particular vibratory tool could be encouraged if the glove reduces the transmission of vibration when it is evaluated without the frequency weighting and does not increase the vibration when it is evaluated with the frequency weighting. A current international standard for the measurement and evaluation of the vibration transmitted by gloves can classify a glove as an antivibration glove when it provides no useful attenuation of vibration, whereas a glove providing useful attenuation of vibration on a specific tool can fail the test.

  8. Measurement, evaluation, and assessment of occupational exposures to hand-transmitted vibration.

    PubMed Central

    Griffin, M J

    1997-01-01

    The measurement of hand-transmitted vibration converts oscillatory movements to a form in which they can be evaluated with respect to human responses and assessed for their acceptability. This paper presents methods of measurement, evaluation, and assessment currently advocated in standards and other forms of guidance. The degree to which the methods of evaluating different frequencies, directions, and durations of vibration affect the assessment of vibration on different tools is illustrated. With the frequency weighting currently used to allow for the effects of different frequencies there is little need to measure vibration at frequencies as high as 1000 Hz; this has significant implications to the design and evaluation of proposed antivibration devices, including gloves. Without the current frequency weighting, vibration at frequencies greater than 250 Hz can contribute to the magnitude of the vibration, but many common causes of injury from hand-transmitted vibration have their dominant components of vibration below 250 Hz. On many powered tools, although the dominant frequency of vibration is the same before and after frequency weighting, the reported magnitude of vibration is greatly affected by the frequency weighting. On tools with dominant low frequencies, their vibration is rated as being of far greater importance relative to other tools when considering frequency-weighted acceleration than when considering unweighted acceleration. It is shown that the effect of considering three axes of vibration as opposed to one axis has a greater effect on some tools than on others. The uncertainties and assumptions involved in the measurement, evaluation, and assessment of hand-transmitted vibration are reviewed. It is suggested that whereas current decisions on health and welfare should be based on current assessment methods, the measurement and evaluation of hand-transmitted vibration should involve the collection and reporting of data which allow other

  9. Measurement, evaluation, and assessment of peripheral neurological disorders caused by hand-transmitted vibration.

    PubMed

    Griffin, Michael J

    2008-04-01

    Regular exposure to hand-transmitted vibration can result in symptoms and signs of peripheral vascular, neurological and other disorders collectively known as the hand-arm vibration syndrome. The measurement of the effects of hand-transmitted vibration involves converting the evidence of disorder (symptoms and signs) into information that can be stored. Evaluation requires the use of scales on which to indicate the severity of the various symptoms and signs. Assessment involves a judgement of severity relative to a criterion, usually for a specific purpose (e.g. to decide on removal from work or compensation). The measurement and evaluation of symptoms and signs is necessary when monitoring patient health and when performing epidemiological studies for research. The assessment of the severity of the hand-arm vibration syndrome is currently performed with staging systems, but the criteria are not clear and not related to defined methods for measuring or evaluating the symptoms and signs. Recognizing that similar symptoms can occur without injury from occupational exposures to hand-transmitted vibration, this paper attempts to define significant peripheral neurological symptoms caused by hand-transmitted vibration (i.e. 'unusual symptoms') and how these symptoms and related signs may be measured. Scales for evaluating the symptoms (e.g. their extent) and the related signs (e.g. their probability relative to the probability of the sign being present in persons not exposed to vibration) are defined. A method of relating unusual symptoms to both the signs of disorder and the pattern of vibration exposure is illustrated. Assessments of severity will vary according to the reasons for assessing the health effects of vibration, and will depend on local practice and convenience, but a way of combining evaluations of symptoms and signs is demonstrated in a staging system. Although inherently complex, the methods may assist the collection of data required to improve

  10. [Measurement and analysis of hand-transmitted vibration of vibration tools in workplace for automobile casting and assembly].

    PubMed

    Xie, X S; Qi, C; Du, X Y; Shi, W W; Zhang, M

    2016-02-20

    To investigate the features of hand-transmitted vibration of common vibration tools in the workplace for automobile casting and assembly. From September to October, 2014, measurement and spectral analysis were performed for 16 typical hand tools(including percussion drill, pneumatic wrench, grinding machine, internal grinder, and arc welding machine) in 6 workplaces for automobile casting and assembly according to ISO 5349-1-2001 Mechanical vibration-Measurement and evaluation of human exposure to hand-transmitted vibration-part 1: General requirements and ISO 5349-2-2001 Mechanical vibration-Measurement and evaluation of human exposure to hand-transmitted vibration-Part 2: Practical guidance for measurement in the workplace. The vibration acceleration waveforms of shearing machine, arc welding machine, and pneumatic wrench were mainly impact wave and random wave, while those of internal grinder, angle grinder, percussion drill, and grinding machine were mainly long-and short-period waves. The daily exposure duration to vibration of electric wrench, pneumatic wrench, shearing machine, percussion drill, and internal grinder was about 150 minutes, while that of plasma cutting machine, angle grinder, grinding machine, bench grinder, and arc welding machine was about 400 minutes. The range of vibration total value(ahv) was as follows: pneumatic wrench 0.30~11.04 m/s(2), grinding wheel 1.61~8.97 m/s(2), internal grinder 1.46~8.70 m/s(2), percussion drill 11.10~14.50 m/s(2), and arc welding machine 0.21~2.18 m/s(2). The workers engaged in cleaning had the longest daily exposure duration to vibration, and the effective value of 8-hour energy-equivalent frequency-weighted acceleration for them[A(8)] was 8.03 m/s(2), while this value for workers engaged in assembly was 4.78 m/s(2). The frequency spectrogram with an 1/3-time frequency interval showed that grinding machine, angle grinder, and percussion drill had a high vibration acceleration, and the vibration limit curve

  11. Factors influencing vibration sense thresholds used to assess occupational exposures to hand transmitted vibration.

    PubMed Central

    Harada, N; Griffin, M J

    1991-01-01

    The effects of various conditions, including temporary threshold shifts (TTS) induced by exposure to vibration on vibration sense thresholds, have been investigated. The vibration sense thresholds of five subjects were measured on the middle fingertip of the left hand. A contactor with a diameter of 7 mm was surrounded by three alternative plates with holes of different sizes. The contact force was controlled at either 1 N, 2 N, or 3 N. For the TTS test, the left hand was exposed to vibration at 20 ms-2 rms for five minutes. The frequencies of both the exposure to vibration and the vibration threshold test were in the range 16 Hz to 500 Hz. Using a surround around the contactor greatly reduced the vibration sense threshold at 16 Hz and 31.5 Hz but increased the threshold at 125 Hz, 250 Hz, and 500 Hz. An effect of contact force was seen only at the higher frequencies; larger contact forces led to lower thresholds at 125 Hz, 250 Hz, and 500 Hz. As temperature of the finger skin decreased, the vibration thresholds increased, with the changes at higher frequencies greater than those at lower frequencies. The TTS at 16 Hz and 31.5 Hz measured 0.5 minutes after exposure to vibration (TTS0.5) were highest after exposures to vibration at lower frequencies. The TTS0.5 at 63 Hz was similar after exposure to all frequencies. The TTS0.5 values at 125 Hz, 250 Hz, and 500 Hz were highest after exposures to vibration at 125 Hz and 250 Hz. It was apparent that the physiological characteristics of vibration sensation at low and high frequencies differed significantly. These findings suggest that two representative frequencies can be used when evaluation the neurological effects of occupational exposures to vibration by means of vibration sense thresholds. PMID:2015210

  12. A Proposed Theory on Biodynamic Frequency Weighting for Hand-Transmitted Vibration Exposure

    PubMed Central

    DONG, Ren G.; WELCOME, Daniel E.; MCDOWELL, Thomas W.; XU, Xueyan S.; KRAJNAK, Kristine; WU, John Z.

    2015-01-01

    The objective of this study is to propose a theory on the biodynamic frequency weighting for studying hand-transmitted vibration exposures and vibration-induced effects. We hypothesize that the development of a vibration effect is the result of two consecutive but synergistic processes: biodynamic responses to input vibration and biological responses to the biomechanical stimuli resulting from the biodynamic responses. Hence, we further hypothesize that the frequency-dependency (W) of the effect generally includes two components: a biodynamic frequency weighting (W1) and a biological frequency weighting (W2), or W=W1•W2. These hypotheses are consistent with the stress and strain analysis theory and methods widely used in structural dynamics and biomechanics. The factorization may make it easier to study the complex frequency-dependency using different approaches: the biodynamic frequency weighting depends on the passive physical response of the system to vibration, and it can thus be determined by examining the biodynamic response of the system using various engineering methods; on the other hand, the biological frequency weighting depends on the biological mechanisms of the effects, and it can be investigated by studying the psychophysical, physiological, and pathological responses. To help test these hypotheses, this study reviewed and further developed methods to derive the finger biodynamic frequency weighting. As a result, preliminary finger biodynamic frequency weightings are proposed. The implications of the proposed theory and the preliminary biodynamic frequency weightings are also discussed. PMID:23060254

  13. A proposed theory on biodynamic frequency weighting for hand-transmitted vibration exposure.

    PubMed

    Dong, Ren G; Welcome, Daniel E; McDowell, Thomas W; Xu, Xueyan S; Krajnak, Kristine; Wu, John Z

    2012-01-01

    The objective of this study is to propose a theory on the biodynamic frequency weighting for studying hand-transmitted vibration exposures and vibration-induced effects. We hypothesize that the development of a vibration effect is the result of two consecutive but synergistic processes: biodynamic responses to input vibration and biological responses to the biomechanical stimuli resulting from the biodynamic responses. Hence, we further hypothesize that the frequency-dependency (W) of the effect generally includes two components: a biodynamic frequency weighting (W1) and a biological frequency weighting (W2), or W=W1• W2. These hypotheses are consistent with the stress and strain analysis theory and methods widely used in structural dynamics and biomechanics. The factorization may make it easier to study the complex frequency-dependency using different approaches: the biodynamic frequency weighting depends on the passive physical response of the system to vibration, and it can thus be determined by examining the biodynamic response of the system using various engineering methods; on the other hand, the biological frequency weighting depends on the biological mechanisms of the effects, and it can be investigated by studying the psychophysical, physiological, and pathological responses. To help test these hypotheses, this study reviewed and further developed methods to derive the finger biodynamic frequency weighting. As a result, preliminary finger biodynamic frequency weightings are proposed. The implications of the proposed theory and the preliminary biodynamic frequency weightings are also discussed.

  14. [Influence of two positions for measuring instrument adapter on measurement of hand-transmitted vibration in grinding machine].

    PubMed

    Xie, X S; Zhang, M; Zheng, Y D; Du, X Y; Qi, C

    2016-06-20

    To investigate the influence of two positions for measuring instrument adapter on the measurement of hand-transmitted vibration in grinding machine using the intraclass correlation coefficient (ICC) of reliability assessment index, and to provide a basis for studies on the measurement standard for hand-transmitted vibration. With reference to the measurement standard for hand-transmitted vibration ISO 5349 Mechanical vibration-Measurement and evaluation of human exposure to hand-transmitted vibration-Part 1: General requirements and Mechanical vibration-Measurement and evaluation of human exposure to hand-transmitted vibration-Part 2: Practical guidance for measurement at the workplace, the domestic AWA5936 hand-transmitted vibration measuring instrument and SVAN-106 hand-transmitted vibration measuring instrument from Poland were used to measure hand-transmitted vibration in 3 workers for grinding machine in a foundry for 5 days continuously from September to October, 2014, and Y-axis data were recorded and compared. In worker A, the "T" -shaped adapter had a significantly higher mean Y-axis accelerated speed effective value than the "O" -shaped adapter [4.34 m/s(2) (95%CI 4.05(-)4.63) vs 2.32 m/s(2) (95%CI 2.27~2.38) , t=13.781, P<0.01]. In workers B and C, AWA5936 "U" -shaped adapter (placed at the position of the handle of grinding machine) had lower degrees of data variation of 12.55% and 15.77%, respectively, suggesting good data stability. The measurement results showed significant differences across different positions of adapter (P<0.01) and between all adapters except "O" -shaped and line-shaped adapters (all P<0.01) , while the measurement results showed no significant differences between the "O" -shaped and line-shaped adapters (P>0.01). The comparison of the measurement results of AWA5936 vibration measuring instrument with an "U" -shaped adapter and SVAN-106 vibration measuring instrument with an "S" -shaped adapter showed an ICC of >0.80 (ICC=0

  15. Do exposure limits for hand-transmitted vibration prevent carpal tunnel syndrome?

    PubMed

    Gillibrand, S; Ntani, G; Coggon, D

    2016-07-01

    An apparently high frequency of carpal tunnel syndrome (CTS) among shipyard workers undergoing health surveillance because of exposure to hand-transmitted vibration (HTV) prompted concerns that current regulatory limits on exposure might not protect adequately against the disorder. To explore whether within regulatory limits, higher exposures to HTV predispose to CTS. As part of a retrospective audit, we compared duration and current intensity of exposure to HTV in cases with new-onset CTS and controls matched for age. Conditional logistic regression was used to quantify associations, which were summarized by odds ratios (ORs) and 95% confidence intervals (CIs). There were 23 cases and 55 controls. After adjustment for body mass index and previous diagnosis of diabetes, no clear associations were observed either with duration of exposure to HTV or with current intensity of exposure. Risk was non-significantly elevated in men with ≥30 years' exposure to HTV (OR 1.6), but in the highest category of current exposure [8-h energy-equivalent frequency-weighted acceleration (A8) ≥ 4.0 m/s(2)], risk was lower than that in the reference category (A8 < 2.5 m/s(2)). Moreover, there was a significantly reduced risk of CTS in men with a previous diagnosis of hand-arm vibration syndrome (HAVS) (OR 0.2, 95% CI 0.1-0.9). We found no evidence that below the current limit for A(8) of 5 m/s(2), higher exposures to HTV predispose to CTS. However, care should be taken not to overlook the possibility of treatable CTS when workers with diagnosed HAVS present with new or worsening sensory symptoms in the hand. © The Author 2016. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Acute effects of shock-type vibration transmitted to the hand-arm system.

    PubMed

    Schäfer, N; Dupuis, H; Hartung, E

    1984-01-01

    The aim of the project was to find out whether shock-type vibration of hand-tools compared to non-impulsive vibration has stronger acute effects on the hand-arm system and therefore needs a stricter evaluation from the occupational health point of view in comparison with the requirements of the Draft International Standard ISO-DIS 5349. Under laboratory conditions, subjects were exposed to simulated vibration of hand-tools (grinder, chain saw, hammer-drill, pneumatic hammer, rivet hammer and nailer). The following evaluation criteria were used: biomechanical transmissibility of the hand-arm system (wrist, elbow joint, shoulder joint); muscle-activity (m. flexor carpi ulnaris, m. biceps, m. triceps); peripheral circulation (skin temperature) and subjective perception (comparison of intensity of standard and test vibrations). The results show no significant difference in acute effects on the hand-arm system between impulsive and non-impulsive type vibrations of the hand-tools tested with respect to the chosen vibration level, short-time exposure (up to 8 min) and evaluation criteria. In summary, therefore, it may be concluded that for the evaluation of shock-type vibration of the hand-tools tested, it is justified to use the existing Draft International Standard ISO-DIS 5349.

  17. Prevalence of Hand-transmitted Vibration Exposure among Grass-cutting Workers using Objective and Subjective Measures

    NASA Astrophysics Data System (ADS)

    Azmir, N. A.; Yahya, M. N.

    2017-01-01

    Extended exposure to hand-transmitted vibration from vibrating machine is associated with an increased occurrence of symptoms of occupational disease related to hand disorder. The present case study is to determine the prevalence and correlation of significant subjective as well as objective variables that induce to hand arm vibration syndrome (HAVS) among hand-held grass-cutting workers in Malaysia. Thus, recommendations are made for grass-cutting workers and grass maintenance service management based on findings. A cross sectional study using adopted subjective Hand Arm Vibration Exposure Risk Assessment (HAVERA) questionnaire from Vibration Injury Network on hand disorder signs and symptoms was distributed to a sample of one hundred and sixty eight male workers from grass and turf maintenance industry that use vibrating machine as part of their work. For objective measure, hand-transmitted vibration measurement was collected on site during operation by the following ISO 5349-1, 2001. Two groups were identified in this research comprising of high exposure group and low-moderate exposure group. Workers also gave information about their personal identification, social history, workers’ health, occupational history and machine safety inspection. There was positive HAVS symptoms relationship between the low-moderate exposure group and high exposure group among hand-held grass-cutting workers. The prevalence ratio (PR) was considered high for experiencing white colour change at fingers and fingers go numb which are 3.63 (1.41 to 9.39) and 4.24 (2.18 to 8.27), respectively. The estimated daily vibration exposure, A(8) differs between 2.1 to 20.7 ms-2 for right hand while 2.7 to 29.1 ms-2 for left hand. The subjects claimed that the feel of numbness at left hand is much stronger compared to right hand. The results suggest that HAVS is diagnosed in Malaysia especially in agriculture sector. The A(8) indicates that the exposure value is more than exposure limit value

  18. Validity of self reported occupational exposures to hand transmitted and whole body vibration

    PubMed Central

    Palmer, K.; Haward, B.; Griffin, M.; Bendall, H.; Coggon, D.

    2000-01-01

    OBJECTIVES—To assess the accuracy with which workers report their exposure to occupational sources of hand transmitted (HTV) and whole body vibration (WBV).
METHODS—179 Workers from various jobs involving exposure to HTV or WBV completed a self administered questionnaire about sources of occupational exposure to vibration in the past week. They were then observed at work over 1 hour, after which they completed a second questionnaire concerning their exposures during this observation period. The feasibility of reported sources of exposure during the past week was examined by questioning managers and by inspection of tools and machines in the workplace. The accuracy of reported sources and durations of exposure in the 1 hour period were assessed relative to what had been observed.
RESULTS—The feasibility of exposure in the previous week was confirmed for 97% of subjects who reported exposure to HTV, and for 93% of subjects who reported exposure to WBV. The individual sources of exposure reported were generally plausible, but occupational use of cars was substantially overreported, possibly because of confusion with their use in travel to and from work. The accuracy of exposures reported during the observation period was generally high, but some sources of HTV were confused—for example, nailing and stapling guns reported as riveting hammers, and hammer drills not distinguished from other sorts of drill. Workers overestimated their duration of exposure to HTV by a median factor of 2.5 (interquartile range (IQR) 1.6-5.9), but estimated durations of exposure were more accurate when the exposure was relatively continuous rather than for intermittent short periods. Reported durations of exposure to WBV were generally accurate (median ratio of reported to observed time 1.1, IQR 1.0-1.2).
CONCLUSIONS—Sources of recent occupational exposure to vibration seem to be reported with reasonable accuracy, but durations of exposure to HTV are systematically

  19. Influence on operator's health of hand-transmitted vibrations from handles of a single-axle tractor.

    PubMed

    Goglia, Vlado; Gospodaric, Zlatko; Filipovic, Dubravko; Djukic, Igor

    2006-01-01

    The operators of the single-axle tractors are especially exposed to hand-arm transmitted vibrations. These vibrations can cause the complex of vascular, neurological and musculoskeletal disorders, collectively named hand-arm vibration syndrome. Among these, the most common disorder is vibration-induced white finger (Raynaud's phenomenon). The vibration levels were measured in three tractor's working conditions, namely idling, transportation and soil tillage. The vibration level on the handles was measured and analysed and the frequency spectra for the chosen working conditions were obtained. The frequency-weighted acceleration, given in m/s2, was calculated and the obtained values are graphically presented. The measured vibration levels are then discussed with regard to the operator's daily exposure limits recommended by the ISO 5349. The vibration levels were much higher in the x and y directions than the z-direction in all working conditions. The vibration total values in idling, transportation and soil tillage were 3.37, 8.37 and 9.62 m/s2, respectively. Results showed that the 10% of workers are exposed to a risk of vibration-induced white finger disorder of the hands after relatively short periods (3-4 years), if the tractor is used 8 hour per day in soil tillage and transportation at full load. Considering the criteria of the ISO 5349, the daily working time with the single-axle tractor should be limited in order to protect the operator and work schedules should be arranged to include vibration-free periods.

  20. An examination of the handheld adapter approach for measuring hand-transmitted vibration exposure

    PubMed Central

    Xu, Xueyan S.; Dong, Ren G.; Welcome, Daniel E.; Warren, Christopher; McDowell, Thomas W.

    2015-01-01

    The use of a handheld adapter equipped with a tri-axial accelerometer is the most convenient and efficient approach for measuring vibration exposure at the hand-tool interface, especially when the adapter is incorporated into a miniature handheld or wrist-strapped dosimeter. To help optimize the adapter approach, the specific aims of this study are to identify and understand the major sources and mechanisms of measurement errors and uncertainties associated with using these adapters, and to explore their improvements. Five representative adapter models were selected and used in the experiment. Five human subjects served as operators in the experiment on a hand-arm vibration test system. The results of this study confirm that many of the handheld adapters can produce substantial overestimations of vibration exposure, and measurement errors can significantly vary with tool, adapter model, mounting position, mounting orientation, and subject. Major problems with this approach include unavoidable influence of the hand dynamic motion on the adapter, unstable attachment, insufficient attachment contact force, and inappropriate adapter structure. However, the results of this study also suggest that measurement errors can be substantially reduced if the design and use of an adapter can be systematically optimized toward minimizing the combined effects of the identified factors. Some potential methods for improving the design and use of the adapters are also proposed and discussed. PMID:26744580

  1. Time frequency characterization of hand-transmitted, impulsive vibrations using analytic wavelet transform

    NASA Astrophysics Data System (ADS)

    Kim, Jay; Welcome, Daniel E.; Dong, Ren G.; Joon Song, Won; Hayden, Charles

    2007-11-01

    Current guidelines to assess health risk of hand-arm vibration are based on the frequency-weighted rms acceleration level, therefore do not fully consider the effect of temporal variations of the spectral energy. Time averaging effect involved with the frequency analysis may severely underestimate the risk of impact tools. A time-frequency ( T- F) analysis is necessary to characterize a highly transient signal whose spectral characteristics change rapidly in time. The analytic wavelet transform (AWT) is an ideal T- F analysis tool as it possesses the advantages of both the Fourier and wavelet transforms. The AWT is applied to acceleration signals measured from six tools, five impact type tools and one relatively steady-type tool, to explore possible improvements of the current risk assessment method of hand-arm vibration exposure. Based on the unique capability of the AWT, several new concepts including frequency-weighted time history, cumulative injury function, and cumulative injury index are defined in this study. Possible applications of these new concepts to hand-arm vibration research are described. Based on the results from this study, needs for future research are discussed.

  2. Hand-transmitted vibration from the steering wheel to drivers of a small four-wheel drive tractor.

    PubMed

    Goglia, V; Gospodarić, Z; Kosutić, S; Filipović, D

    2003-01-01

    The paper presents research results of the vibration transmitted from the steering wheel of the small tractor with a 4-wheel drive to the driver's hands. The vibration measurements were carried out on the tractor randomly chosen from the producer's store-house. Before testing the tractor was examined and adjusted following the producer's recommendations. The vibration levels were measured at idling and at full load. The vibration level on the steering wheel was measured and analyzed and the frequency spectra for the chosen working conditions were obtained. The frequency-weighted acceleration, given in m/s(-2), was calculated. The vibration total value was defined as the root-mean-square of the three component values. The obtained values are graphically represented in accordance with ISO/DIS 5349-1979 and ISO5349-1-2001. The vibration exposure for the predicted 10% prevalance of vibration-induced white finger in accordance with Annex C of the same standard was also tested.

  3. A method to quantify hand-transmitted vibration exposure based on the biodynamic stress concept.

    PubMed

    Dong, R G; Welcome, D E; Wu, J Z

    2007-11-01

    This study generally hypothesized that the vibration-induced biodynamic stress and number of its cycles in a substructure of the hand-arm system play an important role in the development of vibration-induced disorders in the substructure. As the first step to test this hypothesis, the specific aims of this study were to develop a practical method to quantify the biodynamic stress-cycle measure, to compare it with ISO-weighted and unweighted accelerations, and to assess its potential for applications. A mechanical-equivalent model of the system was established using reported experimental data. The model was used to estimate the average stresses in the fingers and palm. The frequency weightings of the stresses in these substructures were derived using the proposed stress-cycle measure. This study found the frequency dependence of the average stress distributed in the fingers is different from that in the palm. Therefore, this study predicted that the frequency dependencies of finger disorders could also be different from those of the disorders in the palm, wrist, and arms. If vibration-induced white finger (VWF) is correlated better with unweighted acceleration than with ISO-weighted acceleration, the biodynamic stress distributed in the fingers is likely to play a more important role in the development of VWF than is th e biodynamic stressdistributed in the other substructures of the hand-arm system. The results of this study also suggest that the ISO weighting underestimates the high-frequency effect on the finger disorder development but it may provide a reasonable risk assessment of the disorders in the wrist and arm.

  4. Development of a hand- transmitted vibration measurement instrument to perform tests in medical equipment according to the international standard IEC 60601-1-2005 Ed.3

    NASA Astrophysics Data System (ADS)

    de Lima, F. F.; Moriya, H. T.; Moraes, J. C. T. B.

    2016-07-01

    According to the sub clause 9.6.3 of the international standard IEC 60601-1-2005, medical electrical equipment must provide means of protection against hazardous hand- transmitted vibrations. Compliance of this sub clause is checked by using a vibration measurement instrument in accordance with ISO 5349-1-2001 standard. The present article describes the development of a vibration measurement instrument to perform vibration measurements tests in medical equipments.

  5. Prevalence and pattern of occupational exposure to hand transmitted vibration in Great Britain: findings from a national survey

    PubMed Central

    Palmer, K.; Griffin, M.; Bendall, H.; Pannett, B.; Coggon, D.

    2000-01-01

    OBJECTIVES—To estimate the number of workers in Great Britain with significant occupational exposure to hand transmitted vibration (HTV). Also, to identify the occupations and industries where such exposures arise, and the main sources of exposure.
METHODS—A questionnaire was posted to 22 194 men and women aged 16-64, comprising 21 201 subjects selected at random from the age-sex registers of 34 general practices in England, Scotland, and Wales, and a further 993 subjects selected at random from the central pay registers of the three armed services. Among other things, the questionnaire asked about exposure to sources of HTV in current and earlier employment. Responses were assessed by occupation and industry, and prevalence estimates for the country as a whole were derived from census information on occupational and industrial populations nationally. Estimates were also made in exposed workers of the average daily dose of vibration (A(8) root mean squared (rms) for the past week, based on their reported sources and durations of exposure.
RESULTS—Usable questionnaires were returned by 12 907 subjects (overall response rate 58%). From these it was estimated that some 4.2 million men and 667 000 women in Great Britain are exposed to HTV at work in a 1 week period, and that personal daily exposures to vibration exceed a suggested action level equivalent to 2.8 ms-2 for 8 hours (A(8) >2.8 ms-2 rms) in at least 1.2 million men and 44 000 women. High estimated doses (A(8) >5 ms-2 rms) arose most often in bricklayers and masons, gardeners and groundsmen, carpenters and joiners, electricians and electrical maintenance fitters, and builders and building contractors. The industries where high A(8) values most often arose were construction, motor vehicle repair and maintenance, manufacture of basic metals, and agriculture. The most common sources of exposure were hammer drills, hand held portable grinders, and jigsaws.
CONCLUSIONS—Exposure to HTV is

  6. Minimum health and safety requirements for workers exposed to hand-transmitted vibration and whole-body vibration in the European Union; a review

    PubMed Central

    Griffin, M

    2004-01-01

    In 2002, the Parliament and Commission of the European Community agreed "minimum health and safety requirements" for the exposure of workers to the risks arising from vibration. The Directive defines qualitative requirements and also quantitative requirements in the form of "exposure action values" and "exposure limit values". The quantitative guidance is based on, but appears to conflict with, the guidance in International Standards for hand-transmitted vibration (ISO 5349) and whole-body vibration (ISO 2631). There is a large internal inconsistency within the Directive for short duration exposures to whole-body vibration: the two alternative methods give very different values. It would appear prudent to base actions on the qualitative guidance (i.e. reducing risk to a minimum) and only refer to the quantitative guidance where there is no other reasonable basis for the identification of risk (i.e. similar exposures are not a suspected cause of injury). Health surveillance and other precautions will be appropriate wherever there is reason to suspect a risk and will not be restricted to conditions where the exposure action value is exceeded. PMID:15090658

  7. Changes over a workshift in aesthesiometric and vibrotactile perception thresholds of workers exposed to intermittent hand transmitted vibration from impact wrenches.

    PubMed Central

    Bovenzi, M; Apostoli, P; Alessandro, G; Vanoni, O

    1997-01-01

    OBJECTIVES: To investigate the changes over a workshift in fingertip tactile perception thresholds in users of impact wrenches exposed to intermittent hand transmitted vibration. A further aim was to assess the relation between acute changes in tactile sensation, sensorineural disorders, and vibration dose. METHODS: The study populations consisted of 30 workers exposed to vibration (16 men and 14 women) and 25 control manual workers (10 men and 15 women). Sensorineural disorders in the fingers and hands were graded according to the staging system of the Stockholm workshop scale. Tactile function was tested by measuring aesthesiometric thresholds (two point discrimination and depth sense perception) and vibrotactile perception thresholds at 16, 31.5, and 125 Hz before and after a workshift. Temporary threshold shift was then calculated as the difference between threshold measures before and after the shift. The measurement and assessment of exposure to vibration were made according to the international standard ISO 5349. The vibration dose accumulated over a workshift (m2s-4h) was estimated for each user of impact wrenches. Daily exposure to vibration was also expressed in terms of eight hour energy equivalent frequency weighted acceleration ((ahw)eq(8) in ms-2 rms). RESULTS: After adjustment for age and alcohol consumption, vibrotactile perception thresholds before exposure were greater in the workers exposed to vibration than in the controls. No differences in aesthesiometric thresholds before the shift were found between the study groups. Sensorineural disorders were mild in the workers exposed to vibration and minor neurological abnormalities were detected at the physical examination. Owing to the intermittent use of impact wrenches, the estimated mean (ahw)eq(8) for the subjects exposed to vibration was low (1.3 ms-2 rms). A significant temporary threshold shift in vibration perception at all test frequencies was found in the workers exposed to vibration but

  8. Determinants explaining the variability of hand-transmitted vibration emissions from two different work tasks: grinding and cutting using angle grinders.

    PubMed

    Liljelind, Ingrid; Pettersson, Hans; Nilsson, Leif; Wahlström, Jens; Toomingas, Allan; Lundström, Ronnie; Burström, Lage

    2013-10-01

    There are numerous factors including physical, biomechanical, and individual that influence exposure to hand-transmitted vibration (HTV) and cause variability in the exposure measurements. Knowledge of exposure variability and determinants of exposure could be used to improve working conditions. We performed a quasi-experimental study, where operators performed routine work tasks in order to obtain estimates of the variance components and to evaluate the effect of determinants, such as machine-wheel combinations and individual operator characteristics. Two pre-defined simulated work tasks were performed by 11 operators: removal of a weld puddle of mild steel and cutting of a square steel pipe. In both tasks, four angle grinders were used, two running on compressed air and two electrically driven. Two brands of both grinding and cutting wheels were used. Each operator performed both tasks twice in a random order with each grinder and wheel and the time to complete each task was recorded. Vibration emission values were collected and the wheel wear was measured as loss of weight. Operators' characteristics collected were as follows: age, body height and weight, length and volume of their hands, maximum hand grip force, and length of work experience with grinding machines (years). The tasks were also performed by one operator who used four machines of the same brand. Mixed and random effects models were used in the statistical evaluation. The statistical evaluation was performed for grinding and cutting separately and we used a measure referring to the sum of the 1-s r.m.s. average frequency-weighted acceleration over time for completing the work task (a(sa)). Within each work task, there was a significant effect as a result of the determinants 'the machine used', 'wheel wear', and 'time taken to complete the task'. For cutting, 'the brand of wheel' used also had a significant effect. More than 90% of the inherent variability in the data was explained by the

  9. Tool-specific performance of vibration-reducing gloves for attenuating fingers-transmitted vibration

    PubMed Central

    Welcome, Daniel E.; Dong, Ren G.; Xu, Xueyan S.; Warren, Christopher; McDowell, Thomas W.

    2016-01-01

    BACKGROUND Fingers-transmitted vibration can cause vibration-induced white finger. The effectiveness of vibration-reducing (VR) gloves for reducing hand transmitted vibration to the fingers has not been sufficiently examined. OBJECTIVE The objective of this study is to examine tool-specific performance of VR gloves for reducing finger-transmitted vibrations in three orthogonal directions (3D) from powered hand tools. METHODS A transfer function method was used to estimate the tool-specific effectiveness of four typical VR gloves. The transfer functions of the VR glove fingers in three directions were either measured in this study or during a previous study using a 3D laser vibrometer. More than seventy vibration spectra of various tools or machines were used in the estimations. RESULTS When assessed based on frequency-weighted acceleration, the gloves provided little vibration reduction. In some cases, the gloves amplified the vibration by more than 10%, especially the neoprene glove. However, the neoprene glove did the best when the assessment was based on unweighted acceleration. The neoprene glove was able to reduce the vibration by 10% or more of the unweighted vibration for 27 out of the 79 tools. If the dominant vibration of a tool handle or workpiece was in the shear direction relative to the fingers, as observed in the operation of needle scalers, hammer chisels, and bucking bars, the gloves did not reduce the vibration but increased it. CONCLUSIONS This study confirmed that the effectiveness for reducing vibration varied with the gloves and the vibration reduction of each glove depended on tool, vibration direction to the fingers, and finger location. VR gloves, including certified anti-vibration gloves do not provide much vibration reduction when judged based on frequency-weighted acceleration. However, some of the VR gloves can provide more than 10% reduction of the unweighted vibration for some tools or workpieces. Tools and gloves can be matched for

  10. Hand-arm vibration syndrome

    PubMed Central

    Shen, Shixin (Cindy); House, Ronald A.

    2017-01-01

    Abstract Objective To provide family physicians with an understanding of the epidemiology, pathogenesis, symptoms, diagnosis, and management of hand-arm vibration syndrome (HAVS), an important and common occupational disease in Canada. Sources of information A MEDLINE search was conducted for research and review articles on HAVS. A Google search was conducted to obtain gray literature relevant to the Canadian context. Additional references were obtained from the articles identified. Main message Hand-arm vibration syndrome is a prevalent occupational disease affecting workers in multiple industries in which vibrating tools are used. However, it is underdiagnosed in Canada. It has 3 components—vascular, in the form of secondary Raynaud phenomenon; sensorineural; and musculoskeletal. Hand-arm vibration syndrome in its more advanced stages contributes to substantial disability and poor quality of life. Its diagnosis requires careful history taking, in particular occupational history, physical examination, laboratory tests to rule out alternative diagnoses, and referral to an occupational medicine specialist for additional investigations. Management involves reduction of vibration exposure, avoidance of cold conditions, smoking cessation, and medication. Conclusion To ensure timely diagnosis of HAVS and improve prognosis and quality of life, family physicians should be aware of this common occupational disease and be able to elicit the relevant occupational history, refer patients to occupational medicine clinics, and appropriately initiate compensation claims. PMID:28292796

  11. Tool-specific performance of vibration-reducing gloves for attenuating palm-transmitted vibrations in three orthogonal directions

    PubMed Central

    Dong, Ren G.; Welcome, Daniel E.; Peterson, Donald R.; Xu, Xueyan S.; McDowell, Thomas W.; Warren, Christopher; Asaki, Takafumi; Kudernatsch, Simon; Brammer, Antony

    2015-01-01

    Vibration-reducing (VR) gloves have been increasingly used to help reduce vibration exposure, but it remains unclear how effective these gloves are. The purpose of this study was to estimate tool-specific performances of VR gloves for reducing the vibrations transmitted to the palm of the hand in three orthogonal directions (3-D) in an attempt to assess glove effectiveness and aid in the appropriate selection of these gloves. Four typical VR gloves were considered in this study, two of which can be classified as anti-vibration (AV) gloves according to the current AV glove test standard. The average transmissibility spectrum of each glove in each direction was synthesized based on spectra measured in this study and other spectra collected from reported studies. More than seventy vibration spectra of various tools or machines were considered in the estimations, which were also measured in this study or collected from reported studies. The glove performance assessments were based on the percent reduction of frequency-weighted acceleration as is required in the current standard for assessing the risk of vibration exposures. The estimated tool-specific vibration reductions of the gloves indicate that the VR gloves could slightly reduce (<5%) or marginally amplify (<10%) the vibrations generated from low-frequency (<25 Hz) tools or those vibrating primarily along the axis of the tool handle. With other tools, the VR gloves could reduce palm-transmitted vibrations in the range of 5%–58%, primarily depending on the specific tool and its vibration spectra in the three directions. The two AV gloves were not more effective than the other gloves with some of the tools considered in this study. The implications of the results are discussed. Relevance to industry Hand-transmitted vibration exposure may cause hand-arm vibration syndrome. Vibration-reducing gloves are considered as an alternative approach to reduce the vibration exposure. This study provides useful information

  12. [The hand-arm vibration syndrome: (II). The diagnostic aspects and fitness criteria].

    PubMed

    Bovenzi, M

    1999-01-01

    Part II of this paper reviews the clinical and laboratory methods to diagnose the neurological, vascular and osteoarticular components of the hand-arm vibration syndrome. The prognosis and reversibility of vibration-induced neurological and vascular disorders after cessation of vibration exposure or the introduction of powered tools equipped with vibration isolation systems are discussed on the basis of the results of follow-up clinical investigations and longitudinal epidemiologic studies. Finally, the review debates some of the methodological aspects connected with the health surveillance of vibration-exposed workers and considers the possible medical contra-indications for prolonged exposure to hand-transmitted vibration.

  13. Hand function in workers with hand-arm vibration syndrome.

    PubMed

    Cederlund, R; Isacsson, A; Lundborg, G

    1999-01-01

    Hand-arm vibration syndrome has been specially addressed in the Scandinavian countries in recent years, but the syndrome is still not sufficiently recognized in many countries. The object of this preliminary study was to describe the nature and character of vibration-induced impairment in the hands of exposed workers. Twenty symptomatic male workers (aged 28 to 65 years) subjected to vibration by hand-held tools were interviewed about subjective symptoms and activities of daily living and were assessed with a battery of objective tests for sensibility, dexterity, grip function, and grip strength. The test results were compared with normative data. The majority of patients complained of cold intolerance, numbness, pain, sensory impairment, and difficulties in handling manual tools and in handwriting. The various objective tests showed considerable variation in indications of pathologic outcome, revealing differences in sensitivity to detect impaired hand function. Semmes-Weinstein monofilament testing for perception of light touch-deep pressure sensation, the small-object shape identification test, and moving two-point discrimination testing for functional sensibility provided the most indications of pathologic outcomes. The authors conclude that vibration-exposed patients present considerable impairment in hand function.

  14. Vibration-reducing gloves: transmissibility at the palm of the hand in three orthogonal directions.

    PubMed

    McDowell, Thomas W; Dong, Ren G; Welcome, Daniel E; Xu, Xueyan S; Warren, Christopher

    2013-01-01

    Vibration-reducing (VR) gloves are commonly used as a means to help control exposures to hand-transmitted vibrations generated by powered hand tools. The objective of this study was to characterise the vibration transmissibility spectra and frequency-weighted vibration transmissibility of VR gloves at the palm of the hand in three orthogonal directions. Seven adult males participated in the evaluation of seven glove models using a three-dimensional hand-arm vibration test system. Three levels of hand coupling force were applied in the experiment. This study found that, in general, VR gloves are most effective at reducing vibrations transmitted to the palm along the forearm direction. Gloves that are found to be superior at reducing vibrations in the forearm direction may not be more effective in the other directions when compared with other VR gloves. This casts doubts on the validity of the standardised glove screening test. Practitioner Summary: This study used human subjects to measure three-dimensional vibration transmissibility of vibration-reducing gloves at the palm and identified their vibration attenuation characteristics. This study found the gloves to be most effective at reducing vibrations along the forearm direction. These gloves did not effectively attenuate vibration along the handle axial direction.

  15. Tool-specific performance of vibration-reducing gloves for attenuating palm-transmitted vibrations in three orthogonal directions.

    PubMed

    Dong, Ren G; Welcome, Daniel E; Peterson, Donald R; Xu, Xueyan S; McDowell, Thomas W; Warren, Christopher; Asaki, Takafumi; Kudernatsch, Simon; Brammer, Antony

    2014-11-01

    Vibration-reducing (VR) gloves have been increasingly used to help reduce vibration exposure, but it remains unclear how effective these gloves are. The purpose of this study was to estimate tool-specific performances of VR gloves for reducing the vibrations transmitted to the palm of the hand in three orthogonal directions (3-D) in an attempt to assess glove effectiveness and aid in the appropriate selection of these gloves. Four typical VR gloves were considered in this study, two of which can be classified as anti-vibration (AV) gloves according to the current AV glove test standard. The average transmissibility spectrum of each glove in each direction was synthesized based on spectra measured in this study and other spectra collected from reported studies. More than seventy vibration spectra of various tools or machines were considered in the estimations, which were also measured in this study or collected from reported studies. The glove performance assessments were based on the percent reduction of frequency-weighted acceleration as is required in the current standard for assessing the risk of vibration exposures. The estimated tool-specific vibration reductions of the gloves indicate that the VR gloves could slightly reduce (<5%) or marginally amplify (<10%) the vibrations generated from low-frequency (<25 Hz) tools or those vibrating primarily along the axis of the tool handle. With other tools, the VR gloves could reduce palm-transmitted vibrations in the range of 5%-58%, primarily depending on the specific tool and its vibration spectra in the three directions. The two AV gloves were not more effective than the other gloves with some of the tools considered in this study. The implications of the results are discussed.

  16. Hand-arm vibration and terrain vehicles.

    PubMed

    Anttonen, H; Virokannas, H; Niskanen, J

    1995-01-01

    Hand-arm vibration was measured on the handlebars of terrain vehicles (N = 36) and a postal inquiry was made among N = 2705 reindeer herders (snowmobile drivers). Since many subjects had also used other vibrating tools the snowmobile group proper (N = 334) was established. In the whole group 19% of the subjects reported having experienced white finger attacks and 48% numbness of the hands. The frequency-weighted acceleration of snowmobile vibration was 3.5 m/s2, and risk evaluation using the ISO 5349 standard predicted the prevalence of white finger well in the snowmobile group proper. The vibration levels were 1.6-7.9 m/s2 on snowmobiles, 5.5-11.8 m/s2 on all-terrain vehicles and 6.9-12.7 m/s2 on terrain motorcycles. The most critical points for damping the vibration were the motor mounting and resonance in the steering yoke. There is need for health care, technical improvements, and other protection means to reduce the symptoms of vibration in driving terrain vehicles.

  17. Vibration-reducing gloves: transmissibility at the palm of the hand in three orthogonal directions

    PubMed Central

    McDowell, Thomas W.; Dong, Ren G.; Welcome, Daniel E.; Xu, Xueyan S.; Warren, Christopher

    2015-01-01

    Vibration-reducing (VR) gloves are commonly used as a means to help control exposures to hand-transmitted vibrations generated by powered hand tools. The objective of this study was to characterise the vibration transmissibility spectra and frequency-weighted vibration transmissibility of VR gloves at the palm of the hand in three orthogonal directions. Seven adult males participated in the evaluation of seven glove models using a three-dimensional hand–arm vibration test system. Three levels of hand coupling force were applied in the experiment. This study found that, in general, VR gloves are most effective at reducing vibrations transmitted to the palm along the forearm direction. Gloves that are found to be superior at reducing vibrations in the forearm direction may not be more effective in the other directions when compared with other VR gloves. This casts doubts on the validity of the standardised glove screening test. Practitioner Summary This study used human subjects to measure three-dimensional vibration transmissibility of vibration-reducing gloves at the palm and identified their vibration attenuation characteristics. This study found the gloves to be most effective at reducing vibrations along the forearm direction. These gloves did not effectively attenuate vibration along the handle axial direction. PMID:24160755

  18. Vascular hand-arm vibration syndrome--magnetic resonance angiography.

    PubMed

    Poole, C J M; Cleveland, T J

    2016-01-01

    The diagnosis of vascular hand-arm vibration syndrome (HAVS) requires consistent symptoms, photographic evidence of digital blanching and sufficient exposure to hand-transmitted vibration (HTV; A(8) > 2.5 m/s2). There is no reliable quantitative investigation for distinguishing HAVS from other causes of Raynaud's phenomenon and from normal individuals. Hypothenar and thenar hammer syndromes produce similar symptoms to HAVS but are difficult to diagnose clinically and may be confused with HAVS. Magnetic resonance angiography (MRA) is a safe and minimally invasive method of visualizing blood vessels. Three cases of vascular HAVS are described in which MRA revealed occlusions of the ulnar, radial and superficial palmar arteries. It is proposed that HTV was the cause of these occlusions, rather than blows to the hand unrelated to vibration, the assumed mechanism for the hammer syndromes. All three cases were advised not to expose their hands to HTV despite one of them being at Stockholm vascular stage 2 (early). MRA should be the investigation of choice for stage 2 vascular HAVS or vascular HAVS with unusual features or for a suspected hammer syndrome. The technique is however technically challenging and best done in specialist centres in collaboration with an occupational physician familiar with the examination of HAVS cases. Staging for HAVS should be developed to include anatomical arterial abnormalities as well as symptoms and signs of blanching. Workers with only one artery supplying a hand, or with only one palmar arch, may be at increased risk of progression and therefore should not be exposed to HTV irrespective of their Stockholm stage.

  19. An examination of an adapter method for measuring the vibration transmitted to the human arms

    PubMed Central

    Xu, Xueyan S.; Dong, Ren G.; Welcome, Daniel E.; Warren, Christopher; McDowell, Thomas W.

    2016-01-01

    The objective of this study is to evaluate an adapter method for measuring the vibration on the human arms. Four instrumented adapters with different weights were used to measure the vibration transmitted to the wrist, forearm, and upper arm of each subject. Each adapter was attached at each location on the subjects using an elastic cloth wrap. Two laser vibrometers were also used to measure the transmitted vibration at each location to evaluate the validity of the adapter method. The apparent mass at the palm of the hand along the forearm direction was also measured to enhance the evaluation. This study found that the adapter and laser-measured transmissibility spectra were comparable with some systematic differences. While increasing the adapter mass reduced the resonant frequency at the measurement location, increasing the tightness of the adapter attachment increased the resonant frequency. However, the use of lightweight (≤15 g) adapters under medium attachment tightness did not change the basic trends of the transmissibility spectrum. The resonant features observed in the transmissibility spectra were also correlated with those observed in the apparent mass spectra. Because the local coordinate systems of the adapters may be significantly misaligned relative to the global coordinates of the vibration test systems, large errors were observed for the adapter-measured transmissibility in some individual orthogonal directions. This study, however, also demonstrated that the misalignment issue can be resolved by either using the total vibration transmissibility or by measuring the misalignment angles to correct the errors. Therefore, the adapter method is acceptable for understanding the basic characteristics of the vibration transmission in the human arms, and the adapter-measured data are acceptable for approximately modeling the system. PMID:26834309

  20. An examination of an adapter method for measuring the vibration transmitted to the human arms.

    PubMed

    Xu, Xueyan S; Dong, Ren G; Welcome, Daniel E; Warren, Christopher; McDowell, Thomas W

    2015-09-01

    The objective of this study is to evaluate an adapter method for measuring the vibration on the human arms. Four instrumented adapters with different weights were used to measure the vibration transmitted to the wrist, forearm, and upper arm of each subject. Each adapter was attached at each location on the subjects using an elastic cloth wrap. Two laser vibrometers were also used to measure the transmitted vibration at each location to evaluate the validity of the adapter method. The apparent mass at the palm of the hand along the forearm direction was also measured to enhance the evaluation. This study found that the adapter and laser-measured transmissibility spectra were comparable with some systematic differences. While increasing the adapter mass reduced the resonant frequency at the measurement location, increasing the tightness of the adapter attachment increased the resonant frequency. However, the use of lightweight (≤15 g) adapters under medium attachment tightness did not change the basic trends of the transmissibility spectrum. The resonant features observed in the transmissibility spectra were also correlated with those observed in the apparent mass spectra. Because the local coordinate systems of the adapters may be significantly misaligned relative to the global coordinates of the vibration test systems, large errors were observed for the adapter-measured transmissibility in some individual orthogonal directions. This study, however, also demonstrated that the misalignment issue can be resolved by either using the total vibration transmissibility or by measuring the misalignment angles to correct the errors. Therefore, the adapter method is acceptable for understanding the basic characteristics of the vibration transmission in the human arms, and the adapter-measured data are acceptable for approximately modeling the system.

  1. An examination of the vibration transmissibility of the hand-arm system in three orthogonal directions

    PubMed Central

    Welcome, Daniel E.; Dong, Ren G.; Xu, Xueyan S.; Warren, Christopher; McDowell, Thomas W.; Wu, John Z.

    2015-01-01

    The objective of this study is to enhance the understanding of the vibration transmission in the hand-arm system in three orthogonal directions (X, Y, and Z). For the first time, the transmitted vibrations distributed on the entire hand-arm system exposed in the three orthogonal directions via a 3-D vibration test system were measured using a 3-D laser vibrometer. Seven adult male subjects participated in the experiment. This study confirms that the vibration transmissibility generally decreased with the increase in distance from the hand and it varied with the vibration direction. Specifically, to the upper arm and shoulder, only moderate vibration transmission was measured in the test frequency range (16 to 500 Hz), and virtually no transmission was measured in the frequency range higher than 50 Hz. The resonance vibration on the forearm was primarily in the range of 16–30 Hz with the peak amplitude of approximately 1.5 times of the input vibration amplitude. The major resonance on the dorsal surfaces of the hand and wrist occurred at around 30–40 Hz and, in the Y direction, with peak amplitude of more than 2.5 times of the input amplitude. At higher than 50 Hz, vibration transmission was effectively limited to the hand and fingers. A major finger resonance was observed at around 100 Hz in the X and Y directions and around 200 Hz in the Z direction. In the fingers, the resonance magnitude in the Z direction was generally the lowest, and the resonance magnitude in the Y direction was generally the highest with the resonance amplitude of 3 times the input vibration, which was similar to the transmissibility at the wrist and hand dorsum. The implications of the results are discussed. Relevance to industry Prolonged, intensive exposure to hand-transmitted vibration could result in hand-arm vibration syndrome. While the syndrome's precise mechanisms remain unclear, the characterization of the vibration transmissibility of the system in the three orthogonal

  2. An examination of the vibration transmissibility of the hand-arm system in three orthogonal directions.

    PubMed

    Welcome, Daniel E; Dong, Ren G; Xu, Xueyan S; Warren, Christopher; McDowell, Thomas W; Wu, John Z

    2015-02-01

    The objective of this study is to enhance the understanding of the vibration transmission in the hand-arm system in three orthogonal directions (X, Y, and Z). For the first time, the transmitted vibrations distributed on the entire hand-arm system exposed in the three orthogonal directions via a 3-D vibration test system were measured using a 3-D laser vibrometer. Seven adult male subjects participated in the experiment. This study confirms that the vibration transmissibility generally decreased with the increase in distance from the hand and it varied with the vibration direction. Specifically, to the upper arm and shoulder, only moderate vibration transmission was measured in the test frequency range (16 to 500 Hz), and virtually no transmission was measured in the frequency range higher than 50 Hz. The resonance vibration on the forearm was primarily in the range of 16-30 Hz with the peak amplitude of approximately 1.5 times of the input vibration amplitude. The major resonance on the dorsal surfaces of the hand and wrist occurred at around 30-40 Hz and, in the Y direction, with peak amplitude of more than 2.5 times of the input amplitude. At higher than 50 Hz, vibration transmission was effectively limited to the hand and fingers. A major finger resonance was observed at around 100 Hz in the X and Y directions and around 200 Hz in the Z direction. In the fingers, the resonance magnitude in the Z direction was generally the lowest, and the resonance magnitude in the Y direction was generally the highest with the resonance amplitude of 3 times the input vibration, which was similar to the transmissibility at the wrist and hand dorsum. The implications of the results are discussed.

  3. Hand-arm vibration disorder among grass-cutter workers in Malaysia.

    PubMed

    Azmir, Nor Azali; Ghazali, Mohd Imran; Yahya, Musli Nizam; Ali, Mohamad Hanafi

    2016-09-01

    Prolonged exposure to hand-transmitted vibration from grass-cutting machines has been associated with increasing occurrences of symptoms and signs of occupational diseases related to hand-arm vibration syndrome (HAVS). A cross-sectional study was carried out using an adopted HAVS questionnaire on hand-arm vibration exposure and symptoms distributed to 168 male workers from the grass and turf maintenance industry who use hand-held grass-cutting machines as part of their work. The prevalence ratio and symptom correlation to HAVS between high and low-moderate exposure risk groups were evaluated. There were positive HAVS symptoms relationships between the low-moderate exposure group and the high exposure group among hand-held grass-cutting workers. The prevalence ratio was considered high because there were indicators that fingers turned white and felt numb, 3.63, 95% CI [1.41, 9.39] and 4.24, 95% CI [2.18, 8.27], respectively. Less than 14.3% of workers stated that they were aware of the occupational hand-arm vibration, and it seemed to be related to the finger blanching and numbness. The results suggest that HAVS is under-diagnosed in Malaysia, especially in the agricultural sectors. More information related to safety and health awareness programmes for HAVS exposure is required among hand-held grass-cutting workers.

  4. [Hand-arm vibration syndrome and upper limbs diseases in the forest workers of Italia meridionale].

    PubMed

    Fenga, C; Rapisarda, V; Valentino, M; Cacciola, A; Deboli, R; Calvo, A; Germanò, D

    2007-01-01

    Vibration exposure of the hand-arm system is associated with an increased risk of upper-limb vascular, neurological and musculoskeletal lesions, or hand-arm vibration syndrome (HAVS). The prevalence of occupational HAVS and upper-limb disorders was studied among 278 Forestry Service workers in Sicily and Calabria. Subjects who used chain-saws (18 weeks/year) had a greater prevalence of peripheral sensory-neural disturbances (28%), upper-limb musculoskeletal disorders (33%) and carpal tunnel syndrome (19%) compared with 260 manual workers from the same Corps not exposed to hand-transmitted vibration. Raynaud's phenomenon was comparable in exposed and control subjects (5.3% vs. 4.7%.) Upper-limb neuropathies were significantly associated with energy-equivalent frequency-weighted acceleration; exposure duration; and cumulative vibration dose (m2/s4h). The variable "years of work with vibrating tools" was strongly associated with peripheral neuropathies; carpal tunnel syndrome; and upper-limb musculotendinous syndromes. Data suggest that in Sicily and Calabria, where the climate is milder than in other areas of Italy, forestry work with hand-held vibrating tools does not entail a greater prevalence of peripheral vascular disorders (Raynaud's phenomenon), while the prevalence of occupational upper-limb neurological and musculoskeletal disorders, in which combined ergonomic and mechanical risk factors have a large pathogenic role, is significantly increased.

  5. Spatial patterns of cutaneous vibration during whole-hand haptic interactions

    PubMed Central

    Hayward, Vincent; Visell, Yon

    2016-01-01

    We investigated the propagation patterns of cutaneous vibration in the hand during interactions with touched objects. Prior research has highlighted the importance of vibrotactile signals during haptic interactions, but little is known of how vibrations propagate throughout the hand. Furthermore, the extent to which the patterns of vibrations reflect the nature of the objects that are touched, and how they are touched, is unknown. Using an apparatus comprised of an array of accelerometers, we mapped and analyzed spatial distributions of vibrations propagating in the skin of the dorsal region of the hand during active touch, grasping, and manipulation tasks. We found these spatial patterns of vibration to vary systematically with touch interactions and determined that it is possible to use these data to decode the modes of interaction with touched objects. The observed vibration patterns evolved rapidly in time, peaking in intensity within a few milliseconds, fading within 20–30 ms, and yielding interaction-dependent distributions of energy in frequency bands that span the range of vibrotactile sensitivity. These results are consistent with findings in perception research that indicate that vibrotactile information distributed throughout the hand can transmit information regarding explored and manipulated objects. The results may further clarify the role of distributed sensory resources in the perceptual recovery of object attributes during active touch, may guide the development of approaches to robotic sensing, and could have implications for the rehabilitation of the upper extremity. PMID:27035957

  6. Spatial patterns of cutaneous vibration during whole-hand haptic interactions.

    PubMed

    Shao, Yitian; Hayward, Vincent; Visell, Yon

    2016-04-12

    We investigated the propagation patterns of cutaneous vibration in the hand during interactions with touched objects. Prior research has highlighted the importance of vibrotactile signals during haptic interactions, but little is known of how vibrations propagate throughout the hand. Furthermore, the extent to which the patterns of vibrations reflect the nature of the objects that are touched, and how they are touched, is unknown. Using an apparatus comprised of an array of accelerometers, we mapped and analyzed spatial distributions of vibrations propagating in the skin of the dorsal region of the hand during active touch, grasping, and manipulation tasks. We found these spatial patterns of vibration to vary systematically with touch interactions and determined that it is possible to use these data to decode the modes of interaction with touched objects. The observed vibration patterns evolved rapidly in time, peaking in intensity within a few milliseconds, fading within 20-30 ms, and yielding interaction-dependent distributions of energy in frequency bands that span the range of vibrotactile sensitivity. These results are consistent with findings in perception research that indicate that vibrotactile information distributed throughout the hand can transmit information regarding explored and manipulated objects. The results may further clarify the role of distributed sensory resources in the perceptual recovery of object attributes during active touch, may guide the development of approaches to robotic sensing, and could have implications for the rehabilitation of the upper extremity.

  7. Hand-arm vibration exposure monitoring with wearable sensor module.

    PubMed

    Austad, Hanne O; Røed, Morten H; Liverud, Anders E; Dalgard, Steffen; Seeberg, Trine M

    2013-01-01

    Vibration exposure is a serious risk within work physiology for several work groups. Combined with cold artic climate, the risk for permanent harm is even higher. Equipment that can monitor the vibration exposure and warn the user when at risk will provide a safer work environment for these work groups. This study evaluates whether data from a wearable wireless multi-parameter sensor module can be used to estimate vibration exposure and exposure time. This work has been focused on the characterization of the response from the accelerometer in the sensor module and the optimal location of the module in the hand-arm configuration.

  8. Hand-arm vibration in tropical rain forestry workers.

    PubMed

    Futatsuka, M; Inaoka, T; Ohtsuka, R; Sakurai, T; Moji, K; Igarashi, T

    1995-01-01

    Working conditions and health hazards including vibration syndrome related to forestry work using chain-saws were studied in Papua New Guinea and Indonesia. The subjects comprised 291 workers including 97 chain-saw operators. The health examination consisted of peripheral circulatory and sensory tests in the upper extremities. The vibration spectrum measured at the handle of the chain-saw indicated that these acceleration levels would lead to a moderately high risk of hand-arm vibration syndrome (HAVS). The peripheral circulatory function tests revealed dysfunction after more than five years vibration exposure. However, in general, the results of the function tests and subjective complaints showed fewer health problems compared to those of Japanese forestry workers. The reason of such differences of vibration effects seem to be the following: (1) warmer climate (more than 25 degrees C throughout the year), (2) young workers and short work experience. (3) short time vibration exposures on working days in the natural forests, (4) seasonal changes in logging work (5) healthy workers effects. Thus, we found no clear evidence that the workers of our study suffered from HAVS. A principal component analysis was applied. The factor score of the components of the reactive dynamics of peripheral circulation differed significantly after more than five years' exposure. On the other hand, we cannot deny the possibility that subclinical dysfunction of peripheral circulation may be caused by chain-saw operation in the tropics in future. Further investigations on the HAVS among forestry workers in the tropic environment are needed.

  9. Vibration and impulsivity analysis of hand held olive beaters.

    PubMed

    Deboli, Roberto; Calvo, Angela; Preti, Christian

    2016-07-01

    To provide more effective evaluations of hand arm vibration syndromes caused by hand held olive beaters, this study focused on two aspects: the acceleration measured at the tool pole and the analysis of the impulsivity, using the crest factor. The signals were frequency weighted using the weighting curve Wh as described in the ISO 5349-1 standard. The same source signals were also filtered by the Wh-bl filter (ISO/TS 15694), because the weighting filter Wh (unlike the Wh-bl filter) could underestimate the effect of high frequency vibration on vibration-induced finger disorders. Ten (experienced) male operators used three beater models (battery powered) in the real olive harvesting condition. High vibration total values were obtained with values never lower than 20 m(-2). Concerning the crest factor, the values ranged from 5 to more than 22. This work demonstrated that the hand held olive beaters produced high impulsive loads comparable to the industry hand held tools.

  10. [Hand-arm vibration syndrome and upper limb disorders associated with forestry work].

    PubMed

    Bovenzi, M; Rui, Francesca; Versini, W; Tommasini, M; Nataletti, P

    2004-01-01

    Occupational exposure to hand-transmitted vibration in forestry workers is associated with an increased risk for vascular, neurological and musculo-skeletal disorders of the upper limbs. To carry out a cross-sectional study of the hand-arm vibration syndrome and soft-tissue disorders of the upper limb in a group of forestry workers employed in the Forestry Service of the Province of Trento (Italy). In the forestry worker group, usage of anti-vibration chain-saws was intermittent over a typical work year (16 weeks/yr, on average). To investigate vascular, neurological and musculo-skeletal disorders of the upper limbs, the forestry workers (n=159) and a control group of manual workers, unexposed to hand-transmitted vibration, employed in the same Forestry Service (n=146) underwent a structured medical interview and a complete physical examination. The clinical diagnoses of vibration-induced white finger (VWF) and carpal tunnel syndrome were made according to internationally recognised consensus criteria. Occupational exposure to hand-transmitted vibration was assessed according to the recommendations of the International Standard ISO 5349-1 (2001). The forestry workers showed an increased prevalence of peripheral sensory-neural disturbances (33.3%), musculo-skeletal disorders of the upper limbs (37.7%), and carpal tunnel syndrome (21.4%) compared to those observed in the control group. There was no significant difference in the prevalence ofRaynaud' sphenomenon between the forestry workers (6.3%) and the controls (4.1%). After adjustment for confounding factors (age, body mass index, tobacco and alcohol consumption), a significant association was observed between peripheral neuropathies (peripheral sensory-neural disorders, carpal tunnel syndrome) and several indices of vibration exposure such as 8-hr energy-equivalent frequency-weighted acceleration [A(8) in m/s2 r.m.s.], duration of exposure (years), and lifetime vibration dose (m2/s4 hr). An excess, although not

  11. Hand vibration: non-contact measurement of local transmissibility.

    PubMed

    Scalise, Lorenzo; Rossetti, Francesco; Paone, Nicola

    2007-10-01

    Grip and push forces required for the use of vibrating tools are considered important influencing inputs for the assessment of hand-vibration transmissibility (TR). At present TR measurements are usually referred to the palm of the hand The aims of the present paper are: to present an original measurement procedure for non-contact assessment of the transmissibility of fingers; to report TR data measured on six points of the hand of nine subjects; to correlate TR with: grip, push, hand volume and BMI. Tests have been carried out using a cylindrical handle mounted on an shaker. A laser Doppler vibrometer is used to measure the vibration velocity. Push force is measured using a force platform, whereas grip force is measured using a capacitive pressure sensor matrix wrapped around the handle. Tests have been conducted on nine healthy subjects. Proximal and distal regions of the second, fourth and fifth fingers have been investigated. Tests were carried out using a push force of: 25, 50 and 75 N. The excitation signal was a broadband random vibration in the band 16-400 Hz with un-weighted rms acceleration level of 6 m/s(2). Results show how in general TR values measured on distal points are higher respect to the proximal points. A resonance peak is present for all the measured points in the band 55-80 Hz. ANOVA analysis showed that TR is not significantly dependent on: BMI, hand volume and push force alone. While TR is significantly dependent on: grip force alone, measurement positions and grip and push force together. The proposed procedure shows the advantage to allow local vibration measurement directly on the fingers without the necessity to apply any contact sensor. Results demonstrate how the transmissibility is significantly different on the point where the acceleration is measured.

  12. Hand arm vibration syndrome among quarry workers in Vietnam.

    PubMed

    Futatsuka, Makoto; Shono, Masahiro; Sakakibara, Hisataka; Quoc Quan, Pham

    2005-03-01

    Few studies have focused on the health effects of vibrating tools on workers in the tropical area. Work conditions and health effects related to rock drill operation were studied in 102 quarry workers, including 73 rock drill operators in Vietnam. We aimed to clarify (1) risk of vibration exposure, (2) occurrence of vibration-induced white finger (VWF), and (3) characteristics of hand-arm vibration syndrome (HAVS). Total weighted r.m.s. acceleration of the Chinese -or Russian-made rock drills, was 45-55 m/s(2). According to work observation studies, daily exposure time to vibration was 160-210 min. ISO5349 predicted that this exposure level would be associated with a high risk of HAVS in workers. We found no clear evidence of VWF. There may be several reasons why no worker exhibited VWF: (1) warmer work conditions, (2) younger and less experienced workers, (3) seasonal changes in work operations, and (4) healthy worker effect. On the other hand, 5-10% of rock drill operators might be suffering from moderate HAVS which was sensori-neural type dominant. There may be some characteristic features of HAVS among quarry workers in the tropical area.

  13. Vibrotactile perception and effects of short-term exposure to hand-arm vibration.

    PubMed

    Burström, Lage; Lundström, Ronnie; Hagberg, Mats; Nilsson, Tohr

    2009-07-01

    This study clarifies whether the established frequency weighting procedure for evaluating exposure to hand-transmitted vibration can effectively evaluate the temporary changes in vibrotactile perception thresholds due to pre-exposure to vibration. In addition, this study investigates the relationship between changes of the vibrotactile perception thresholds and the normalized energy-equivalent frequency-weighted acceleration. The fingers of 10 healthy subjects, five male and five female, were exposed to vibration under 16 conditions with a combination of different frequencies, intensities, and exposure times. The vibration frequencies were 31.5 and 125 Hz and exposure lasted between 2 and 16 min. According to International Organization for Standardization (ISO) 5349-1, the energy-equivalent frequency-weighted acceleration for the experimental time of 16 min is 2.5 or 5.0 m s(-2) root-mean-square, corresponding to a 8-h equivalent acceleration, A(8), of approximately 0.5 and 0.9 m s(-2), respectively. A measure of the vibrotactile perception thresholds was conducted before the different exposures to vibration. Immediately after the vibration exposure, the acute effect was measured continuously on the exposed index finger for the first 75 s, followed by 30 s of measures every minute for a maximum of 10 min. If the subject's thresholds had not recovered, the measures continued for a maximum of 30 min with measurements taken every 5 min. Pre-exposure to vibration significantly influenced vibrotactile thresholds. This study concludes that the influence on the thresholds depends on the frequency of the vibration stimuli. Increased equivalent frequency-weighted acceleration resulted in a significant change in threshold, but the thresholds were unaffected when changes in the vibration magnitude were expressed as the frequency-weighted acceleration or the unweighted acceleration. Moreover, the frequency of the pre-vibration exposure significantly influenced (up to 25 min

  14. Motor synergies for dampening hand vibration during human walking.

    PubMed

    Togo, Shunta; Kagawa, Takahiro; Uno, Yoji

    2012-01-01

    This study investigated the motion required to carry a cup filled with water without spilling it, which is a common human dexterous task. This task requires the individual to dampen hand vibration while walking. We hypothesize that a reduction in hand jerk and a constant cup angle are required to achieve this task. We measured movements while human subjects carried a cup with water (WW task) and with stones (WS task) using a three-dimensional position measurement system and then analyzed joint coordination. We empirically confirmed that the value of hand jerk and the variance in cup angle in the WW task were smaller than those in the WS task. We used uncontrolled manifold (UCM) analysis to quantify joint coordination corresponding to the motor synergy required to reduce the hand jerk and variance of the cup angle. UCM components, which did not affect the hand jerk and cup angle, were larger than orthogonal components, which directly affected the hand jerk and cup angle in the WW task. These results suggest that there is a coordinated control mechanism that reduces hand jerk and maintains a constant cup angle when carrying a cup filled with water without spilling it. In addition, we suggest that humans adopt a flexible and coordinated control strategy of allowing variance independent of the variables that should be controlled to achieve this dexterous task.

  15. Equivalent comfort contours for vertical vibration of steering wheels: effect of vibration magnitude, grip force, and hand position.

    PubMed

    Morioka, Miyuki; Griffin, Michael J

    2009-09-01

    Vehicle drivers receive tactile feedback from steering-wheel vibration that depends on the frequency and magnitude of the vibration. From an experiment with 12 subjects, equivalent comfort contours were determined for vertical vibration of the hands at two positions with three grip forces. The perceived intensity of the vibration was determined using the method of magnitude estimation over a range of frequencies (4-250 Hz) and magnitudes (0.1-1.58 ms(-2) r.m.s.). Absolute thresholds for vibration perception were also determined for the two hand positions over the same frequency range. The shapes of the comfort contours were strongly dependent on vibration magnitude and also influenced by grip force, indicating that the appropriate frequency weighting depends on vibration magnitude and grip force. There was only a small effect of hand position. The findings are explained by characteristics of the Pacinian and non-Pacinian tactile channels in the glabrous skin of the hand.

  16. Evaluation of hand-arm and whole-body vibrations in construction and property management.

    PubMed

    Coggins, Marie A; Van Lente, Eric; McCallig, Margaret; Paddan, Gurmail; Moore, Ken

    2010-11-01

    To identify and measure the magnitude of hand-arm vibration (HAV) and whole-body vibration (WBV) sources (tools, vehicles etc.) in use within a previously unexamined sector: a construction and property management company. To evaluate the effect of factors such as age of tool, materials being worked on, number and location of tool handles, tool weight, and manufacturer brand on HAV magnitude and the effect of factors such as manufacturer machine brand, terrain, and work task on WBV magnitude. This study was carried out in a construction and property management company, employees (n = 469) working in the engineering services and maintenance departments who use vibrating equipment as part of their work were invited to participate. Two hundred and eighty-nine employees working as general operatives, excavator drivers, stone masons, carpenters, labourers, fitters, welders, and gardeners agreed to participate. A total of 20 types of hand tool (n = 264) and 11 types of vehicle (n = 158) in use within the company were selected for inclusion in the study. Five pieces of equipment had never previously been measured. Vibration measurements were carried out in accordance with ISO 5349-1 (Mechanical vibration-measurement and assessment of human exposure to hand transmitted vibration-Part 1: general guidance. 2001) (HAV) and ISO 2631-1 (Mechanical vibration and shock: evaluation of human exposure to WBV in the working environment. Part 1-general requirements. 1997) (WBV). Vibration measurements were made while workers were operating the equipment as part of their normal work activities. A wide range of vibration emission values were recorded for most tool types, e.g. orbital sanders (1.39-10.90 m s⁻²) and angle grinders (0.28-12.25 m s⁻²), and vehicle, e.g. forklifts (0.41-1.00 m s⁻²) and tractors (0.04-0.42 m s⁻²). Vibration magnitudes were largely consistent with those found in previous studies. The highest HAV magnitude was measured on a demolition hammer (13.3 m

  17. Hand-arm vibration syndrome in Swedish car mechanics

    PubMed Central

    Barregard, L; Ehrenstrom, L; Marcus, K

    2003-01-01

    Aims: To assess the occurrence of hand-arm vibration syndrome (HAVS) in Swedish car mechanics, and the relation between HAVS and duration of exposure. Methods: A total of 806 mechanics answered a questionnaire on vascular and neurological symptoms, and exposure to vibrations. Mechanics with symptoms, and some mechanics without symptoms, were invited to a clinical examination, including also a timed Allen test. Vascular and neurological symptoms were classified using the Stockholm Workshop scales. The mean daily exposure (mainly using nut-runners) was 14 minutes and the mean exposure duration, 12 years. Published data have shown vibration levels in nut-runners of about 3.5 m/s2. Results: In the questionnaire, 24% reported cold induced white finger (WF), 25% persistent numbness, and 13%, reduced grip force. The clinical examination showed a prevalence of vibration induced white finger (VWF) of about 15%, mainly in stage 2, and after 20 years, of 25%. A survival analysis showed similar results. We found that the International Organisation for Standardisation (ISO) model underestimates the risk of VWF. The incidence after 1975 was 19 cases per 1000 person-years. Slow refill times in the timed Allen test were common (15% had a refill time of >20 seconds), and associated with the presence of VWF. The clinical examination revealed neurological symptoms in the hands in about 25% of subjects, mainly at stage 2. After 20 years, the prevalence was 40%. The questionnaire items on WF and numbness both showed likelihood ratios of 13. Conclusion: HAVS is common among Swedish car mechanics in spite of short daily exposure times. This underlines the need for preventive measures. PMID:12660377

  18. Assessment of vibration levels associated with hand-held roadbreakers.

    PubMed

    Tasker, E G

    1986-08-01

    The hand-held roadbreaker plays a vital role in enabling the British gas distribution workforce to install gas supply pipework. Hence, any potential problem which could lead to a restriction of the use of this equipment would present pipework installation departments with serious operational problems. A test program was therefore set up to enable risks to operators to be quantified. The vibration levels measured exceeded proposed limits laid down in current guidelines for vibration exposure. If these limits were realistic, a high prevalence of vibration-induced white finger (VWF) would have been expected. However, a survey of the workforce using the roadbreakers indicated a VWF prevalence of 20 times less than that predicted by the guidelines. It was concluded that a possible explanation could be that the current frequency-weighting factors used in the guidelines are inappropriate for application to this type of equipment with dominant frequencies below 25 Hz. The application of the current weighting factors to the test data produced during the program led to high weighted acceleration values and unrealistic dose-response relationships. It is proposed that the application of the various guidelines to the use of this equipment be reconsidered.

  19. Vibration reduction on hand-held grinders by automatic balancing.

    PubMed

    Lindell, H

    1996-02-01

    By automatically balanced hand hold grinders, vibrations are reduced to at least half and thereby reducing the estimated risk for vibration injuries by a factor of four. Simultaneously less grinding disc consumption and better grinding results are obtained. Vibration from grinders originates mainly from unbalance in the grinding wheel. Grinding wheels are low price products. With uneven distribution of mass and coarse tolerances. This gives rise to out-of-balance, which changes as the wheel wears. By fitting an automatic balancer, that consists of steel balls contained in a cylindrical ball race on the shaft of the grinder, unbalances will be compensate for in the machine during grinding. The time it takes for an automatic balancer to stabilize is only a few tenths of a second. When grinding, the balancer is stable, even during substantial changes in speed. The technique is applicable to almost all grinding machines on the market and the first grinders using the technique have just been put on the market.

  20. An improved biomechanical model for simulating the strain of the hand-arm system under vibration stress.

    PubMed

    Fritz, M

    1991-01-01

    In order to define relationships between the vibration stress and the strain of the human hand-arm system a biomechanical model was developed. The four masses of the model representing the hand, the forearm and the upper arm were connected by dampers and springs in two perpendicular directions. Simulating muscle activity, damped torsion springs were included additionally. The motions of the model were described by a differential matrix equation which was solved by using a 'transfer matrix routine' as well as by numerical integration. Thus, functions with harmonic or transient time courses could be selected as an excitation. The simulated vibrations were compared with those of other hand-arm models. The forces and torques transmitted between the masses, and the energy dissipated by the dampers were computed for several combinations of exciter frequencies and accelerations. The dependence of torques upon excitation agreed fairly well with the behaviour of the arm muscles under vibration as described by various investigators. At frequencies above 100 Hz the energy was dissipated mainly by the dampers between the masses near to the exciter. Transferring this result to the hand-arm system it shows that at high frequencies energy is dissipated by the hand and its palmar tissues and this might be one cause for the incidence of vibration-induced white finger disease.

  1. Evaluation of anti-vibration interventions for the hand during sheet metal assembly work.

    PubMed

    Dale, Ann Marie; Rohn, A E; Burwell, A; Shannon, W; Standeven, J; Patton, A; Evanoff, B

    2011-01-01

    Occupational use of vibrating hand tools contributes to the development of upper extremity disorders. While several types of vibration damping materials are commercially available, reductions in vibration exposure are usually tested in the laboratory rather than in actual work environments. This study evaluated reductions in hand vibration with different vibration damping interventions under actual work conditions. Three experienced sheet metal assemblers at a manufacturing facility installed sheet metal fasteners with a pneumatic tool using no vibration damping (bare hand) and each of six anti-vibration interventions (five different gloves and a viscoelastic tool wrap). Vibration was measured with tri-axial accelerometers on the tool and the back of the hand. Unweighted mean vibration measured at the hand showed reduced vibration (p<0.001) for all six interventions (range = 3.07-5.56 m/s(2)) compared to the bare hand condition (12.91 m/s(2)). All of the interventions were effective at reducing vibration at the hand during testing under usual work conditions. Field testing beyond laboratory-based testing accounts for the influences of worker, tools, and materials on vibration transmission to the body from specific work operations. © 2011 - IOS Press and the authors. All rights reserved

  2. [The risk of vibrations to the hand-arm system and cumulative trauma disorders in shoe manufacturing: a clinical case report].

    PubMed

    Delbianco, M; Olivetti, G; De Donato, S R; Ricciotti, M; Campana, A

    1993-01-01

    The article reports the case of a woman working in a shoe factory who had been using vibrating tools for 5 years. Because of paresthesia in her left hand, in 1989 she underwent various diagnostic trials that revealed an initial carpal tunnel syndrome of the left wrist and a homolateral epicondylitis. Measurement of the vibrations transmitted to the hand from the vibrating tool confirmed the probability of a high risk of exposure for the hand-arm system. Such adverse effects have been described by British authors as "cumulative trauma disorders" and were confirmed in this study. The importance of further studies aimed at estimating the type and degree of exposure to vibrations in shoe manufacturing workers is stressed.

  3. The Hettinger hand vibration test, vasospasm, and glaucoma.

    PubMed

    Goldberg, I; Chai, E; Chia, A; Benscher, C; Bauman, A; Chen, J

    1999-06-01

    Ocular vasospasm in response to local and/or systemic stimuli may contribute to ischemia of the optic nerve. The Hettinger hand vibration test was applied to patients with and without glaucoma to identify subgroups with a high systemic vasospastic tendency. A total of 580 subjects were tested (113 controls, 86 glaucoma suspects, 270 with primary open-angle glaucoma, 71 with secondary open-angle glaucoma, 30 with normal-tension glaucoma, and 10 with angle-closure glaucoma). The frequency distribution curve of Hettinger scores (HS) was bimodal, suggesting two distinct groups. Within each diagnostic group, a subpopulation with a high HS could be identified. Multivariate analysis demonstrated a significant association between the nonselective topical beta-blocker timolol and higher mean HS (P = 0.04) and a significantly higher proportion of subjects with HS of 1.5 or more (P = 0.01). Although subjects taking systemic beta1-selective blockers had significantly lower mean HS (P = 0.04), the proportion of patients with HS of 1.5 or more was not affected significantly by topical and systemic beta1-selective blocker use. Whereas topical nonselective beta-blockers may have an adverse effect on vasospastic tendency, systemic beta1-selective blockers may be partially protective against this effect.

  4. Dose-response relation between exposure to two types of hand-arm vibration and sensorineural perception of vibration.

    PubMed Central

    Virokannas, H

    1995-01-01

    OBJECTIVES--31 railway workers and 32 lumberjacks were examined to compare the dose-response relation between the exposure to two types of hand-arm vibration and the sensory disturbances in peripheral nerves as evaluated by the vibration perception thresholds (VPTs). METHODS--Clinical examinations were carried out that included measurements of the VPTs, and electroneuromyography (ENMG), and an inquiry to confirm the use of vibrating tools. Diseases of the central nervous system and neuropathies were checked by inquiry and a clinical examination, diabetes was excluded by a blood sample analysis, and the subjects with carpal tunnel syndrome confirmed with ENMG were excluded from the study. RESULTS--Lifetime use of hand held tamping machines (railway workers) and chain saws (lumberjacks) had a significant correlation with the VPTs at frequencies from 32 to 500 Hz. The increase of the VPTs (250 Hz) in relation to use of vibrating tools was 1.8-fold higher on average in the whole group and 2.3-fold higher in the young (< 45) railway workers who had used hand held tamping machines, than in the corresponding groups of lumberjacks, who had used chain saws, whereas the frequency weighted acceleration of vibration in tamping machines was fourfold. CONCLUSION--There was a significant dose-response relation between the exposure to hand-arm vibration and the VPTs. The VPTs as a function of the frequency weighted acceleration of vibration and the exposure to vibration gave promising results for assessment of the risk of damage to sensory nerves induced by vibration. PMID:7795756

  5. A thin rod is all that is needed to transmit vibrations from a shaker device (at bottom) and the win

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A thin rod is all that is needed to transmit vibrations from a shaker device (at bottom) and the wingtip of the Active Aeroelastic Wing F/A-18 research aircraft during ground vibration testing at NASA's Dryden Flight Research Center. Wiring hanging down from the wingtip launcher rail transfer signals from accelerometers and other sensors mounted on the wing's upper surface to monitoring equipment. The tests help engineers determine if aerodynamically induced vibrations are controlled or suppressed during flight, and were the last major ground tests prior to the initiation of research flights.

  6. A thin rod is all that is needed to transmit vibrations from a shaker device (at bottom) and the win

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A thin rod is all that is needed to transmit vibrations from a shaker device (at bottom) and the wingtip of the Active Aeroelastic Wing F/A-18 research aircraft during ground vibration testing at NASA's Dryden Flight Research Center. Wiring hanging down from the wingtip launcher rail transfer signals from accelerometers and other sensors mounted on the wing's upper surface to monitoring equipment. The tests help engineers determine if aerodynamically induced vibrations are controlled or suppressed during flight, and were the last major ground tests prior to the initiation of research flights.

  7. Control Model for Dampening Hand Vibrations Using Information of Internal and External Coordinates

    PubMed Central

    Togo, Shunta; Kagawa, Takahiro; Uno, Yoji

    2015-01-01

    In the present study, we investigate a control mechanism that dampens hand vibrations. Here, we propose a control method with two components to suppress hand vibrations. The first is a passive suppression method that lowers the joint stiffness to passively dampen the hand vibrations. The second is an active suppression method that adjusts an equilibrium point based on skyhook control to actively dampen the hand vibrations. In a simulation experiment, we applied these two methods to dampen hand vibrations during the shoulder’s horizontal oscillation. We also conducted a measurement experiment wherein a subject’s shoulder was sinusoidally oscillated by a platform that generated horizontal oscillations. The results of the measurement experiments showed that the jerk of each part of the arm in a task using a cup filled with water was smaller than the shoulder jerk and that in a task with a cup filled with stones was larger than the shoulder jerk. Moreover, the amplitude of the hand trajectory in both horizontal and vertical directions was smaller in a task using a cup filled with water than in a task using a cup filled with stones. The results of the measurement experiments were accurately reproduced by the active suppression method based on skyhook control. These results suggest that humans dampen hand vibrations by controlling the equilibrium point through the information of the external workspace and the internal body state rather than by lowering joint stiffness only by using internal information. PMID:25876037

  8. Control model for dampening hand vibrations using information of internal and external coordinates.

    PubMed

    Togo, Shunta; Kagawa, Takahiro; Uno, Yoji

    2015-01-01

    In the present study, we investigate a control mechanism that dampens hand vibrations. Here, we propose a control method with two components to suppress hand vibrations. The first is a passive suppression method that lowers the joint stiffness to passively dampen the hand vibrations. The second is an active suppression method that adjusts an equilibrium point based on skyhook control to actively dampen the hand vibrations. In a simulation experiment, we applied these two methods to dampen hand vibrations during the shoulder's horizontal oscillation. We also conducted a measurement experiment wherein a subject's shoulder was sinusoidally oscillated by a platform that generated horizontal oscillations. The results of the measurement experiments showed that the jerk of each part of the arm in a task using a cup filled with water was smaller than the shoulder jerk and that in a task with a cup filled with stones was larger than the shoulder jerk. Moreover, the amplitude of the hand trajectory in both horizontal and vertical directions was smaller in a task using a cup filled with water than in a task using a cup filled with stones. The results of the measurement experiments were accurately reproduced by the active suppression method based on skyhook control. These results suggest that humans dampen hand vibrations by controlling the equilibrium point through the information of the external workspace and the internal body state rather than by lowering joint stiffness only by using internal information.

  9. [Hand bones disorders in vibrational disease caused by local vibration should be considered as pathogenetic characteristic of the disease].

    PubMed

    Liubchenko, P N; Evlashko, Iu P; Dmitruk, L I

    2011-01-01

    Opposite to the authors of the publication, that dystrophic changes in locomotory apparatus of hands and shoulders girdle could not be considered as vibration disease signs, the article authors believe that hand bone changes--tuberosity of distal finger bones, cystic transparency, local osteoporosis--could be pathogenetic signs of vibration disease, along with vascular and neurologic signs. The authors agree that periarthrosis, miofibrosis, if characterized properly through sanitary and hygienic regulations in new List of Occupational diseases, that will be put into practical medicine in the nearest future, could be considered as second occupational disease in the same patient.

  10. Assessment of coarse and fine hand motor performance in asymptomatic subjects exposed to hand-arm vibration.

    PubMed

    Popević, Martin B; Janković, Srđan M; Borjanović, Srđan S; Jovičić, Slavica R; Tenjović, Lazar R; Milovanović, Aleksandar P S; Bulat, Petar

    2014-03-01

    A frequently encountered exposure profile for hand-arm vibration in contemporary occupational setting comprises workers with a long history of intermittent exposure but without detectable signs of hand-arm vibration syndrome (HAVS). Yet, most of the published studies deal with developed HAVS cases, rarely discussing the biological processes that may be involved in degradation of manual dexterity and grip strength when it can be most beneficial - during the asymptomatic stage. In the present paper, a group of 31 male asymptomatic vibration-exposed workers (according to the Stockholm Workshop Scale) were compared against 30 male controls. They were tested using dynamometry and dexterimetry (modelling coarse and fine manual performance respectively) and cold provocation was done to detect possible differences in manual performance drop on these tests. The results showed reduced manual dexterity but no significant degradation in hand grip strength in the exposed subjects. This suggests that intermittent exposure profile and small cumulative vibration dose could only lead to a measurable deficit in manual dexterity but not hand grip strength even at non-negligible A(8) levels and long term exposures.

  11. Application of vibration to wrist and hand skin affects fingertip tactile sensation.

    PubMed

    Lakshminarayanan, Kishor; Lauer, Abigail W; Ramakrishnan, Viswanathan; Webster, John G; Seo, Na Jin

    2015-07-14

    A recent study showed that fingertip pads' tactile sensation can improve by applying imperceptible white-noise vibration to the skin at the wrist or dorsum of the hand in stroke patients. This study further examined this behavior by investigating the effect of both imperceptible and perceptible white-noise vibration applied to different locations within the distal upper extremity on the fingertip pads' tactile sensation in healthy adults. In 12 healthy adults, white-noise vibration was applied to one of four locations (dorsum hand by the second knuckle, thenar and hypothenar areas, and volar wrist) at one of four intensities (zero, 60%, 80%, and 120% of the sensory threshold for each vibration location), while the fingertip sensation, the smallest vibratory signal that could be perceived on the thumb and index fingertip pads, was assessed. Vibration intensities significantly affected the fingertip sensation (P < 0.01) in a similar manner for all four vibration locations. Specifically, vibration at 60% of the sensory threshold improved the thumb and index fingertip tactile sensation (P < 0.01), while vibration at 120% of the sensory threshold degraded the thumb and index fingertip tactile sensation (P < 0.01) and the 80% vibration did not significantly change the fingertip sensation (P > 0.01), all compared with the zero vibration condition. This effect with vibration intensity conforms to the stochastic resonance behavior. Nonspecificity to the vibration location suggests the white-noise vibration affects higher level neuronal processing for fingertip sensing. Further studies are needed to elucidate the neural pathways for distal upper extremity vibration to impact fingertip pad tactile sensation. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  12. Application of vibration to wrist and hand skin affects fingertip tactile sensation

    PubMed Central

    Lakshminarayanan, Kishor; Lauer, Abigail W; Ramakrishnan, Viswanathan; Webster, John G; Seo, Na Jin

    2015-01-01

    A recent study showed that fingertip pads’ tactile sensation can improve by applying imperceptible white-noise vibration to the skin at the wrist or dorsum of the hand in stroke patients. This study further examined this behavior by investigating the effect of both imperceptible and perceptible white-noise vibration applied to different locations within the distal upper extremity on the fingertip pads’ tactile sensation in healthy adults. In 12 healthy adults, white-noise vibration was applied to one of four locations (dorsum hand by the second knuckle, thenar and hypothenar areas, and volar wrist) at one of four intensities (zero, 60%, 80%, and 120% of the sensory threshold for each vibration location), while the fingertip sensation, the smallest vibratory signal that could be perceived on the thumb and index fingertip pads, was assessed. Vibration intensities significantly affected the fingertip sensation (P < 0.01) in a similar manner for all four vibration locations. Specifically, vibration at 60% of the sensory threshold improved the thumb and index fingertip tactile sensation (P < 0.01), while vibration at 120% of the sensory threshold degraded the thumb and index fingertip tactile sensation (P < 0.01) and the 80% vibration did not significantly change the fingertip sensation (P > 0.01), all compared with the zero vibration condition. This effect with vibration intensity conforms to the stochastic resonance behavior. Nonspecificity to the vibration location suggests the white-noise vibration affects higher level neuronal processing for fingertip sensing. Further studies are needed to elucidate the neural pathways for distal upper extremity vibration to impact fingertip pad tactile sensation. PMID:26177959

  13. Validity and inter-observer reliability of subjective hand-arm vibration assessments.

    PubMed

    Coenen, Pieter; Formanoy, Margriet; Douwes, Marjolein; Bosch, Tim; de Kraker, Heleen

    2014-07-01

    Exposure to mechanical vibrations at work (e.g., due to handling powered tools) is a potential occupational risk as it may cause upper extremity complaints. However, reliable and valid assessment methods for vibration exposure at work are lacking. Measuring hand-arm vibration objectively is often difficult and expensive, while often used information provided by manufacturers lacks detail. Therefore, a subjective hand-arm vibration assessment method was tested on validity and inter-observer reliability. In an experimental protocol, sixteen tasks handling powered tools were executed by two workers. Hand-arm vibration was assessed subjectively by 16 observers according to the proposed subjective assessment method. As a gold standard reference, hand-arm vibration was measured objectively using a vibration measurement device. Weighted κ's were calculated to assess validity, intra-class-correlation coefficients (ICCs) were calculated to assess inter-observer reliability. Inter-observer reliability of the subjective assessments depicting the agreement among observers can be expressed by an ICC of 0.708 (0.511-0.873). The validity of the subjective assessments as compared to the gold-standard reference can be expressed by a weighted κ of 0.535 (0.285-0.785). Besides, the percentage of exact agreement of the subjective assessment compared to the objective measurement was relatively low (i.e., 52% of all tasks). This study shows that subjectively assessed hand-arm vibrations are fairly reliable among observers and moderately valid. This assessment method is a first attempt to use subjective risk assessments of hand-arm vibration. Although, this assessment method can benefit from some future improvement, it can be of use in future studies and in field-based ergonomic assessments.

  14. A Cross Sectional Study on Hand-arm Vibration Syndrome among a Group of Tree Fellers in a Tropical Environment

    PubMed Central

    SU, Anselm Ting; MAEDA, Setsuo; FUKUMOTO, Jin; MIYAI, Nobuyuki; ISAHAK, Marzuki; YOSHIOKA, Atsushi; NAKAJIMA, Ryuichi; BULGIBA, Awang; MIYASHITA, Kazuhisa

    2014-01-01

    This study aimed to explore the clinical characteristics of hand arm vibration syndrome (HAVS) in a group of tree fellers in a tropical environment. We examined all tree fellers and selected control subjects in a logging camp of central Sarawak for vibration exposure and presence of HAVS symptoms utilizing vibrotactile perception threshold test (VPT) and cold water provocation test (CWP). None of the subjects reported white finger. The tree fellers reported significantly higher prevalence of finger coldness as compared to the control subjects (OR=10.32, 95%CI=1.21–87.94). A lower finger skin temperature, longer fingernail capillary return time and higher VPT were observed among the tree fellers as compared to the control subjects in all fingers (effect size >0.5). The VPT following CWP of the tree fellers was significantly higher (repeated measures ANOVA p=0.002, partial η2=0.196) than the control subject. The A (8) level was associated with finger tingling, numbness and dullness (effect size=0.983) and finger coldness (effect size=0.524) among the tree fellers. Finger coldness and finger tingling, numbness and dullness are important symptoms for HAVS in tropical environment that may indicate vascular and neurological damage due to hand-transmitted vibration exposure. PMID:24739764

  15. A cross sectional study on hand-arm vibration syndrome among a group of tree fellers in a tropical environment.

    PubMed

    Su, Anselm Ting; Maeda, Setsuo; Fukumoto, Jin; Miyai, Nobuyuki; Isahak, Marzuki; Yoshioka, Atsushi; Nakajima, Ryuichi; Bulgiba, Awang; Miyashita, Kazuhisa

    2014-01-01

    This study aimed to explore the clinical characteristics of hand arm vibration syndrome (HAVS) in a group of tree fellers in a tropical environment. We examined all tree fellers and selected control subjects in a logging camp of central Sarawak for vibration exposure and presence of HAVS symptoms utilizing vibrotactile perception threshold test (VPT) and cold water provocation test (CWP). None of the subjects reported white finger. The tree fellers reported significantly higher prevalence of finger coldness as compared to the control subjects (OR=10.32, 95%CI=1.21-87.94). A lower finger skin temperature, longer fingernail capillary return time and higher VPT were observed among the tree fellers as compared to the control subjects in all fingers (effect size >0.5). The VPT following CWP of the tree fellers was significantly higher (repeated measures ANOVA p=0.002, partial η(2)=0.196) than the control subject. The A (8) level was associated with finger tingling, numbness and dullness (effect size=0.983) and finger coldness (effect size=0.524) among the tree fellers. Finger coldness and finger tingling, numbness and dullness are important symptoms for HAVS in tropical environment that may indicate vascular and neurological damage due to hand-transmitted vibration exposure.

  16. 12-channel receive array with a volume transmit coil for hand/wrist imaging at 7 T.

    PubMed

    Raghuraman, Sairamesh; Mueller, Matthias F; Zbýň, Štefan; Baer, Peter; Breuer, Felix A; Friedrich, Klaus M; Trattnig, Siegfried; Lanz, Titus; Jakob, Peter M

    2013-07-01

    To develop a coil configuration for high-resolution imaging of different regions of the hand and wrist at 7 T. A quadrature bandpass birdcage and a 12-channel high density receive array were developed for imaging metacarpus and wrist. Workbench and magnetic resonance imaging (MRI) measurements were done to characterize the coil and obtain in vivo images. Electromagnetic simulations were performed to assess the uniformity of transmit profile and calculate the specific absorption rate (SAR). The results obtained show that the constructed transmit coil can be used in combination with receive arrays, without the need to retune the same. The developed wrist array was used to produce images of ultrahigh resolution (0.19 × 0.19 × 0.5 mm(3) ), revealing fine anatomical details. Simulations show that a near-uniform transmit profile is possible throughout the hand. No inhomogeneities were observed in the transmit profile, unlike a human head or abdomen at 7 T, due to the small volume of the hand and its low conductive regions. While transceive arrays are usually preferred at 7 T due to issues related to decrease in wavelength, it is shown in this study that with regard to hand-imaging optimized high-density receive arrays are a good solution to obtain images of extremely fine resolution of different regions. Copyright © 2012 Wiley Periodicals, Inc.

  17. Reduction of the vibration of the hand-arm system by optimization of rotary hammer drills.

    PubMed

    Weinert, K; Gillmeister, F

    1996-02-01

    When operating a hand-held vibrating power tool, for example impact drills and rotary hammers, high vibration loads are introduced into the hand-arm system of the operator. In the long run these mechanical vibrations can lead to health problems of the hand-arm system. Hammer drilling tools for treatment of mineral materials are offered with many different designs of the cutting edge in the diameter range between 16 mm and 50 mm. In this research project the influences of the cutting edge design of drilling tools on the vibration characteristics of rotary hammers are investigated. The vibration exposure of the hand-arm system due to the tool and the volume of chip production are regarded. The gauge being a combination of the weighted acceleration and the drilling capacity. Based on the current spectrum of drillings tools neutral test have been developed to examine geometrical parameters. Both sets of drilling tools have been subjected to the same test programme. The analysis of the results led to the definition of the characteristics of an optimized rotary hammer drilling tool. Lists of criterions have been developed for the different groups of tools. Using these it is possible to create drilling tools optimized for vibration exposure. This was demonstrated by prototype drilling tools. The comparison of the results showed, that the averaged volume of chip production could be significantly improved by modifying the design of the drilling tools retaining the weighted acceleration. The comparison also showed that the total vibration severity parameter decreased.

  18. Memory for fingertip forces: passive hand muscle vibration interferes with predictive grip force scaling.

    PubMed

    Nowak, Dennis A; Rosenkranz, Karin; Hermsdörfer, Joachim; Rothwell, John

    2004-06-01

    When subjects repetitively lift an object, the grip force they select is influenced by the mechanical object properties of the preceding lift. Similar effects on grip force scaling are observed whether the subsequent lift is performed with the same hand or the hand contralateral to the preceding lift. Here we demonstrate that passive vibration of the hand muscles involved in the generation of grip force in the interval between two blocks of lifting trials interferes with predictive grip force scaling. Following ten trials in which subjects lifted an object with constant mechanical properties with the dominant hand, muscle vibration was given to the first interosseus and adductor pollicis muscles of the dominant hand during a 10-min rest period. Compared with the last lift preceding vibration, peak rates of grip force increase and peak grip forces were scaled too high during the first lift following vibration whether the lift was made with the dominant or non-dominant hand. Subjects scaled grip force accurately to the object properties within three lifts following vibration. If subjects rested for 10 min after the first ten trials and received no vibration, then there was no significant difference in the peak grip force or its rate of increase between the last lift preceding rest and the first lift following it. We suggest that vibration impairs the memory processes responsible for predictive grip force scaling. Our data are consistent with the recent suggestion that these memory processes are neither specific for a certain motor action nor do they reflect internal representations of mechanical object properties.

  19. Vibration exposure for selected power hand tools used in automobile assembly.

    PubMed

    Radwin, R G; Armstrong, T J; Vanbergeijk, E

    1990-09-01

    A practical method for assessing vibration exposure for workers operating vibrating hand tools on an automobile assembly line is presented. Vibration exposure is difficult to assess directly using many fast Fourier transform (FFT) spectral analyzers because of long task cycle times. Exposure time cannot be accurately estimated using time standards because of the high variability between operators and work methods. Furthermore, because workers frequently move about and get into inaccessible spaces, it is difficult to record vibration without interfering with the operation. A work sampling method was used for determining vibration exposure time by attaching accelerometers to the tools and suspending a battery-operated digital data logger from the air hose. Vibration acceleration and frequency spectra for each tool were obtained off-line replicating actual working conditions and analyzed together with exposure time data for determining individual worker vibration exposure. Eight pneumatic vibrating power hand tools, representing tools commonly used in an automobile assembly plant, were studied. Spectra for the rotary and reciprocating power tools and had large distinct dominant fundamental frequencies occurring in a narrow frequency range between 35 Hz and 150 Hz. These frequencies corresponded closely to tool free-running speeds, suggesting that major spectral component frequencies may be predicted on the basis of speed for some tools.

  20. Postocclusive reactive hyperemia in hand-arm vibration syndrome.

    PubMed

    Stoyneva, Zlatka

    2016-01-01

    To assess laser Doppler-recorded postocclusive reactive hyperemic responses in vibration-induced Raynaud's phenomenon and compare it with primary and secondary to sclerodermy Raynaud's phenomenon. Thirty patients with vibration-induced Raynaud's phenomenon and 30 healthy controls and patients with primary and secondary to sclerodermy Raynaud's phenomenon were investigated. Fingerpulp skin blood flow was monitored by laser Doppler flowmetry during postocclusive reactive hyperemia test. Lower initial perfusion values were established in all the patients with Raynaud's phenomenon compared to the healthy controls (p < 0.0001). The postocclusive reactive hyperemic peak was lower in all the Raynaud's phenomenon groups compared to the controls (p < 0.0001). The postocclusive and basal perfusions were lower in the secondary Raynaud's phenomenon groups compared to the control and the primary Raynaud's phenomenon groups (p < 0.0001). The velocities to postocclusive hyperemic peak were lower in all the Raynaud's phenomenon patients (p < 0.0001), so were in the vibration-induced (p < 0.002) and the sclerodermy Raynaud's phenomenon (p < 0.004) groups in relation to the primary Raynaud's phenomenon group. The perfusion values and the velocities were significantly influenced by the initial superficial skin temperatures and perfusions, while the velocities were dependent also on gender, and the hyperemic peak on age. Postocclusive reactive hyperemia is abnormal in all Raynaud's phenomenon patients. Laser Doppler-recorded reactive hyperemia test contributes to diagnosing Raynaud's phenomenon and has proved to be valuable for group analysis. The applied method is not sensitive enough to discriminate adequately the type of Raynaud's phenomenon among individual cases. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  1. [Main criteria for the occupational licensure of individualized hand protection against local vibration].

    PubMed

    Butkovskaia, Z M; Smirnov, V V

    1999-01-01

    Hygienic certification of individual means protecting hands against local vibration requires special laboratory and industrial studies considering specific preset criteria. The criteria choice should consider functional state of major body systems involved and capacity to work in specific industrial process. For manually operated machines, the criteria are set within the limits of mutual influence in the system: manually operated machine (its vibration strength characteristics)--operator (state and changes of his major physiologic functions)--occupational environment (peculiarities).

  2. Review and Evaluation of Hand-Arm Coordinate Systems for Measuring Vibration Exposure, Biodynamic Responses, and Hand Forces.

    PubMed

    Dong, Ren G; Sinsel, Erik W; Welcome, Daniel E; Warren, Christopher; Xu, Xueyan S; McDowell, Thomas W; Wu, John Z

    2015-09-01

    The hand coordinate systems for measuring vibration exposures and biodynamic responses have been standardized, but they are not actually used in many studies. This contradicts the purpose of the standardization. The objectives of this study were to identify the major sources of this problem, and to help define or identify better coordinate systems for the standardization. This study systematically reviewed the principles and definition methods, and evaluated typical hand coordinate systems. This study confirms that, as accelerometers remain the major technology for vibration measurement, it is reasonable to standardize two types of coordinate systems: a tool-based basicentric (BC) system and an anatomically based biodynamic (BD) system. However, these coordinate systems are not well defined in the current standard. Definition of the standard BC system is confusing, and it can be interpreted differently; as a result, it has been inconsistently applied in various standards and studies. The standard hand BD system is defined using the orientation of the third metacarpal bone. It is neither convenient nor defined based on important biological or biodynamic features. This explains why it is rarely used in practice. To resolve these inconsistencies and deficiencies, we proposed a revised method for defining the realistic handle BC system and an alternative method for defining the hand BD system. A fingertip-based BD system for measuring the principal grip force is also proposed based on an important feature of the grip force confirmed in this study.

  3. Transcriptional Pathways Altered in Response to Vibration in a Model of Hand-Arm Vibration Syndrome.

    PubMed

    Waugh, Stacey; Kashon, Michael L; Li, Shengqiao; Miller, Gerome R; Johnson, Claud; Krajnak, Kristine

    2016-04-01

    The aim of this study was to use an established model of vibration-induced injury to assess frequency-dependent changes in transcript expression in skin, artery, and nerve tissues. Transcript expression in tissues from control and vibration-exposed rats (4 h/day for 10 days at 62.5, 125, or 250 Hz; 49 m/s, rms) was measured. Transcripts affected by vibration were used in bioinformatics analyses to identify molecular- and disease-related pathways associated with exposure to vibration. Analyses revealed that cancer-related pathways showed frequency-dependent changes in activation or inhibition. Most notably, the breast-related cancer-1 pathway was affected. Other pathways associated with breast cancer type 1 susceptibility protein related signaling, or associated with cancer and cell cycle/cell survivability were also affected. Occupational exposure to vibration may result in DNA damage and alterations in cell signaling pathways that have significant effects on cellular division.

  4. Transcriptional Pathways Altered in Response to Vibration in a Model of Hand-Arm Vibration Syndrome

    PubMed Central

    Waugh, Stacey; Kashon, Michael L.; Li, Shengqiao; Miller, Gerome R.; Johnson, Claud; Krajnak, Kristine

    2016-01-01

    Objective The aim of this study was to use an established model of vibration-induced injury to assess frequency-dependent changes in transcript expression in skin, artery, and nerve tissues. Methods Transcript expression in tissues from control and vibration-exposed rats (4 h/day for 10 days at 62.5, 125, or 250 Hz; 49 m/s2, rms) was measured. Transcripts affected by vibration were used in bioinformatics analyses to identify molecular- and disease-related pathways associated with exposure to vibration. Results Analyses revealed that cancer-related pathways showed frequency-dependent changes in activation or inhibition. Most notably, the breast-related cancer-1 pathway was affected. Other pathways associated with breast cancer type 1 susceptibility protein related signaling, or associated with cancer and cell cycle/cell survivability were also affected. Conclusion Occupational exposure to vibration may result in DNA damage and alterations in cell signaling pathways that have significant effects on cellular division. PMID:27058473

  5. Tremor and hand-arm vibration syndrome (HAVS) in road maintenance workers.

    PubMed

    Bast-Pettersen, Rita; Ulvestad, Bente; Færden, Karl; Clemm, Thomas Aleksander C; Olsen, Raymond; Ellingsen, Dag Gunnar; Nordby, Karl-Christian

    2017-01-01

    The aim of this study was to evaluate postural and rest tremor among workers using vibrating hand tools, taking into account the possible effects of toxicants such as alcohol and tobacco. A further aim was to study workers diagnosed with hand-arm vibration syndrome (HAVS) at the time of examination. This study comprises 103 road maintenance workers, 55 exposed to vibrating hand tools (age 41.0 years; range 21-62) and 48 referents (age 38.5 years; range 19-64). They were examined with the CATSYS Tremor Pen(®). Exposure to vibrating tools and serum biomarkers of alcohol and tobacco consumption were measured. Cumulative exposure to vibrating tools was associated with increased postural (p < 0.01) and rest tremor (p < 0.05) and with a higher Center Frequency of postural tremor (p < 0.01) among smokers and users of smokeless tobacco. Rest tremor Center Frequency was higher than postural tremor frequency (p < 0.001). The main findings indicate an association between cumulative exposure to hand-held vibrating tools, tremor parameters and consumption of tobacco products. The hand position is important when testing for tremor. Rest tremor had a higher Center Frequency. Postural tremor was more strongly associated with exposure than rest tremor. The finding of increased tremor among the HAVS subjects indicated that tremor might be a part of the clinical picture of a HAVS diagnosis. As with all cross-sectional studies, inferences should be made with caution when drawing conclusions about associations between exposure and possible effects. Future research using longitudinal design is required to validate the findings of the present study.

  6. The use of hand perfusion scintigraphy to assess Raynaud's phenomenon associated with hand-arm vibration syndrome.

    PubMed

    Lee, Kyung-Ann; Chung, Hyung Woo; Lee, Sang-Heon; Kim, Hae-Rim

    2017-06-30

    This study aimed to evaluate the hand perfusion scintigraphic features of hand-arm vibration syndrome (HAVS) and to compare these with the features of primary and secondary Raynaud's phenomenon (RP) associated with systemic sclerosis (SSc). Hand perfusion scintigraphy was performed in 57 patients with primary RP, 71 patients with HAVS-related RP, and 15 patients with SSc-related RP. We calculated 6 ratios: chilled to ambient hand and wrist ratios of the first peak height, initial slope, and blood pool uptake. We analysed 3 morphologic characteristics: slow progress pattern, paradoxically increased uptake pattern, and inhomogeneous radioactivity uptake. All of the 71 patients with HAVS-related RP were mine workers. The chilled to ambient hand ratios of the first peak height, the initial slope, and the blood pool uptake were significantly lower in patients with HAVS-related occupational RP than in patients with primary RP. The presence of a paradoxically increased uptake pattern was significantly lower in HAVS than in primary RP. There were significant differences in hand perfusion scintigraphic features between primary RP and HAVS. These results suggest that the underlying pathophysiology of the two diseases differs.

  7. A study of hand vibration on chipping and grinding operators, part II: Four-degree-of-freedom lumped parameter model of the vibration response of the human hand

    NASA Astrophysics Data System (ADS)

    Reynolds, D. D.; Falkenberg, R. J.

    1984-08-01

    The results of the development of a four-degree-of-freedom, lumped parameter model of the vibration response characteristics of the human hand are presented. For this study dynamic compliance measurements were made on 75 foundry workers. Curve fitting techniques were then employed to identify the values of the model parameters that yielded empirically generated dynamic compliance curves that correlated well with the measured dynamic compliance values. The agreement was good between 20 Hz and 1000 Hz in the X- and Y-directions. The agreement was good between 20 Hz and 1000 Hz in the Z-direction.

  8. A method for two-dimensional characterization of animal vibrational signals transmitted along plant stems.

    PubMed

    McNett, Gabriel D; Miles, Ronald N; Homentcovschi, Dorel; Cocroft, Reginald B

    2006-12-01

    Conventional approaches to measuring animal vibrational signals on plant stems use a single transducer to measure the amplitude of vibrations. Such an approach, however, will often underestimate the amplitude of bending waves traveling along the stem. This occurs because vibration transducers are maximally sensitive along a single axis, which may not correspond to the major axis of stem motion. Furthermore, stem motion may be more complex than that of a bending wave propagating along a single axis, and such motion cannot be described using a single transducer. Here, we describe a method for characterizing stem motion in two dimensions by processing the signals from two orthogonally positioned transducers. Viewed relative to a cross-sectional plane, a point on the stem surface moves in an ellipse at any one frequency, with the ellipse's major axis corresponding to the maximum amplitude of vibration. The method outlined here measures the ellipse's major and minor axes, and its angle of rotation relative to one of the transducers. We illustrate this method with measurements of stem motion during insect vibrational communication. It is likely the two-dimensional nature of stem motion is relevant to insect vibration perception, making this method a promising avenue for studies of plant-borne transmission.

  9. The Temporary Threshold Shift of Vibratory Sensation Induced by Hand-Arm Vibration Composed of Four One-Third Octave Band Vibrations

    NASA Astrophysics Data System (ADS)

    Nishiyama, K.; Taoda, K.; Yamashita, H.; Watanabe, S.

    1997-03-01

    The aim of the present study was to define the multiple effect hand-arm vibration composed of four equally effective one-third octave band vibrations (63 Hz, 125 Hz, 250 Hz and 500 Hz) on the temporary threshold shift in vibratory sensation.Seven healthy subjects were exposed to vibration by grasping a vibrated handle in a soundproof thermo-regulated room. The vibratory sensation threshold at 125 Hz was measured before and after vibration exposure at an exposed fingertip. At first we determined each acceleration of the component one-third octave band vibrations for each subject. These should induce the same magnitude of temporary threshold shift in vibratory sensation immediately after the vibration exposure (TTSv.0as induced by the reference one-third octave band vibration (250 Hz, 4g). We measured TTSv.tfor the exposures of the composed vibrations and the four component vibrations. TTSv.0was determined for each exposure according to the exponential recovery model stated in the previous study.The TTSv.0induced by the composite vibration was not longer than that which might have been induced by each component vibration. This result confirms our previous speculation that the component of the vibration inducing the largest TTSv.0determines TTSv.0by broadband random vibration.

  10. Biodynamic response at the palm of the human hand subjected to a random vibration.

    PubMed

    Dong, Ren G; McDowell, Thomas W; Welcome, Daniel E

    2005-01-01

    This study investigated the biodynamic response (BR) distributed at the palm of the hand subjected to a random vibration. Twelve male subjects were used in the experiment. Each subject applied three coupling actions (grip-only, push-only, and combined grip and push) on a simulated tool handle at three different levels (50, 75, and 100 N) of palm force. This study found that the hand-arm system resonated mostly in the frequency range of 20 to 50 Hz, depending on the specific test treatment and individual characteristics. The maximum vibration power transmission through the palm occurred at the resonant frequency. Increasing the effective palm force generally increased the BR magnitude and resonant frequency. The apparent stiffness measured at the middle frequencies (80-100 Hz) is correlated to the BR in almost the entire frequency range (20-1,000 Hz). Under the same palm force, the push-only action corresponded to the highest BR values while the grip-only action generally produced the lowest values. Since the resonant frequency range matches the dominant vibration frequency range of many percussive tools, it is anticipated that the palm BR and vibration power transmission may have an association with vibration-induced injuries or disorders in the wrist-arm system among the workers using these tools.

  11. Muscular forearm activation in hand-grip tasks with superimposition of mechanical vibrations.

    PubMed

    Fattorini, L; Tirabasso, A; Lunghi, A; Di Giovanni, R; Sacco, F; Marchetti, E

    2016-02-01

    The purpose of this paper is to evaluate the muscular activation of the forearm, with or without vibration stimuli at different frequencies while performing a grip tasks of 45s at various level of exerted force. In 16 individuals, 9 females and 7 males, the surface electromyogram (EMG) of extensor carpi radialis longus and the flexor carpi ulnari muscles were assessed. At a short latency from onset EMG, RMS and the level of MU synchronization were assessed to evaluate the muscular adaptations. Whilst a trend of decay of EMG Median frequency (MDFd) was employed as an index of muscular fatigue. Muscular tasks consists of the grip of an instrumented handle at a force level of 20%, 30%, 40%, 60% of the maximum voluntary force. Vibration was supplied by a shaker to the hand in mono-frequential waves at 20, 30, 33 and 40Hz. In relation to EMG, RMS and MU synchronization, the muscular activation does not seem to change with the superimposition of the mechanical vibrations, on the contrary a lower MDFd was observed at 33Hz than in absence of vibration. This suggests an early muscular fatigue induced by vibration due to the fact that 33Hz is a resonance frequency for the hand-arm system.

  12. Symptoms of hand-arm vibration syndrome in gas distribution operatives

    PubMed Central

    Palmer, K.; Crane, G.; Inskip, H.

    1998-01-01

    OBJECTIVES: To survey the prevalence and severity of hand-arm vibration syndrome symptoms (HAVS), and to estimate past and current exposure to hand held vibrating tools in a sample of gas distribution operatives breaking and re-instating road surfaces. METHODS: 153 gas distribution operatives (participation rate 81%) from three company districts were assessed by an administered questionnaire, a clinical examination, and a simple cold challenge test to the hands. Exposure histories were taken aided by a picture album of past and current tools. Information was obtained from several sources on the likely vibratory characteristics of those tools. Estimates were thus obtained of the frequency of blanching and neurological complaints in operatives, and of their lifetime hours of exposure and lifetime dose of vibration. RESULTS: On average, the sample had spent 16 years in employment involving use of vibratory tools. 24% had symptoms or signs of blanching after use of tools in the industry; 46% had troublesome persistent complaints of paraesthesiae or numbness, and these symptoms extended into the hands or arms in 18% of workers. In 5.9% the distribution of symptoms was suggestive of carpal tunnel syndrome; and of ulnar nerve entrapment in a further 3.9%. The risks of blanching and neurological complaints rose significantly with lifetime hours of use of vibrating tools and lifetime dose of vibration. Symptoms were generally mild and apparent only after a prolonged interval, but there were exceptions, and cases had occurred after lower recent exposures. CONCLUSIONS: It has been suggested that aspects of the gas distribution operative's work mitigate against the risk normally anticipated from use of pneumatic road breaking tools. By contrast our data suggest that symptoms of HAVS do occur, given sufficient exposure, a finding relevant not only to gas supply workers, but also to workers from other industries who break and repair road surfaces.   PMID:9930095

  13. Vibrations transmitted to human subjects through passenger seats and considerations of passenger comfort

    NASA Technical Reports Server (NTRS)

    Leatherwood, J. D.

    1975-01-01

    An experimental study was conducted to determine the vertical and lateral vibration-transmission characteristics of several types of transport vehicle seats (two aircraft and one bus) to obtain preliminary estimates and comparisons of the ride acceptability of the various seat types. Results of this investigation indicate that from the standpoint of human comfort the seats exhibit undesirable dynamic response characteristics. Amplification of floor vibrations occurred at the frequencies known to be most critical for human comfort in both vertical and lateral axes. An average transmissibility function for aircraft seats was tabulated together with the associated variability for use by designers who incorporate similar types of seats in their vehicles. The acceptability of vibrations resulting from floor inputs of 0.10g and 0.15g was low over a broad range of frequencies for both axes and all seat types, and was especially low at frequencies where the input was being amplified.

  14. Nailfold capillary morphological characteristics of hand-arm vibration syndrome: a cross-sectional study

    PubMed Central

    Chen, QingSong; Chen, GuiPing; Xiao, Bin; Lin, HanSheng; Qu, HongYing; Zhang, DanYing; Shi, MaoGong; Lang, Li; Yang, Bei; Yan, MaoSheng

    2016-01-01

    Objective The purpose of this study was to investigate the characteristics of nailfold capillaroscopy associated with hand-arm vibration syndrome (HAVS). Methods In total, 113 male gold miners were recruited: 35 workers who were chronically exposed to vibration and developed vibration-induced white finger were defined as the HAVS group, 39 workers who were exposed to vibration but did not have HAVS were classified as the vibration-exposed controls (VEC) group, and 39 workers without vibration exposure were categorised as the non-VEC (NVEC) group. Video capillaroscopy was used to capture images of the 2nd, 3rd and 4th fingers of both hands. The following nailfold capillary characteristics were included: number of capillaries/mm, avascular areas, haemorrhages and enlarged capillaries. The experiments were carried out in the same winter. All characteristics were evaluated under blinded conditions. Results Significant differences in all morphological characteristics existed between the groups (p<0.05). Avascular areas in the HAVS, VEC and NVEC groups appeared in 74.3%, 43.6% and 25.0% of participants, respectively. A higher percentage of participants had haemorrhages in the HAVS group (65.7%) compared with the other groups (VEC: 7.7% and NVEC: 7.5%). The number of capillaries/mm, input limb width, output limb width, apical width, and ratio of output limb and input limb all had more than 70% sensitivity or specificity of their cut-off value. Conclusions Nailfold capillary characteristics, especially the number of capillaries/mm, avascular areas, haemorrhages, output limb width, input limb width and apical width alterations, revealed significant associations with HAVS. PMID:27888176

  15. Hand-arm vibration syndrome: clinical characteristics, conventional electrophysiology and quantitative sensory testing.

    PubMed

    Rolke, Roman; Rolke, Silke; Vogt, Thomas; Birklein, Frank; Geber, Christian; Treede, Rolf-Detlef; Letzel, Stephan; Voelter-Mahlknecht, Susanne

    2013-08-01

    Workers exposed to vibrating tools may develop hand-arm vibration syndrome (HAVS). We assessed the somatosensory phenotype using quantitative sensory testing (QST) in comparison to electrophysiology to characterize (1) the most sensitive QST parameter for detecting sensory loss, (2) the correlation of QST and electrophysiology, and (3) the frequency of a carpal tunnel syndrome (CTS) in HAVS. QST, cold provocation tests, fine motor skills, and median nerve neurography were used. QST included thermal and mechanical detection and pain thresholds. Thirty-two patients were examined (54 ± 11 years, 91% men) at the more affected hand compared to 16 matched controls. Vibration detection threshold was the most sensitive parameter to detect sensory loss that was more pronounced in the sensitivity range of Pacinian (150 Hz, x12) than Meissner's corpuscles (20 Hz, x3). QST (84% abnormal) was more sensitive to detect neural dysfunction than conventional electrophysiology (37% abnormal). Motor (34%) and sensory neurography (25%) were abnormal in HAVS. CTS frequency was not increased (9.4%). Findings are consistent with a mechanically-induced, distally pronounced motor and sensory neuropathy independent of CTS. HAVS involves a neuropathy predominantly affecting large fibers with a sensory damage related to resonance frequencies of vibrating tools. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  16. A descriptive study of women injured by hand-arm vibration.

    PubMed

    Bylund, Sonya H; Burström, Lage; Knutsson, Anders

    2002-04-01

    The aim of this study was to describe the symptoms and the prognosis of vibration injuries in women. The investigation was based on a study of 374 women who had reported an injury due to hand-arm vibration to the Social Insurance Office or had received financial compensation from the Swedish Labor Market Insurance scheme during 1988-1997. Information on, for example, self-rated health symptoms and vibration exposure was collected by means of a questionnaire. On average, the first symptoms started after 7 yr of exposure and the first visit to a doctor took place after 11 yr. Neurological symptoms developed after a shorter period of exposure compared to vascular symptoms, 6.8 and 9.2 yr, respectively. The prevalence of numbness at the time of reporting the injury was 91% and the prevalence of white fingers was reported by 54%. The occupational group with the highest prevalence of vibration injuries was dental technicians. Two thirds of the women had stopped using vibrating machines in their work. Among the women who suffered from white fingers when they reported the injury, 50% declared impairment or no improvement of the symptoms. One woman in five was retired and the same number of women had retrained due to the occupational injury.

  17. Combined effects of noise and hand-arm vibration on auditory organ and peripheral circulation

    NASA Astrophysics Data System (ADS)

    Miyakita, T.; Miura, H.; Futatsuka, M.

    1991-12-01

    This paper first presents an overview of an epidemiological study on noise-induced hearing loss (NIHL) in relation to vibration-induced white finger (VWF). Secondly, the results obtained in a model experiment with a chain-saw under laboratory conditions are discussed from the viewpoints of elucidating the etiological mechanisms of VWF and NIHL. In the epidemiological study, in which 499 chain-saw workers were examined, chain-saw workers with VWF showed a significantly greater hearing loss at high frequencies than those without VWF. Next, an experimental study was designed to determine whether a combination of noise and vibration produced more pronounced changes in temporary shifts of finger skin temperature and temporary threshold shift (TTS) of hearing than those resulting from exposure to either stress alone. The results suggested that noise might play a part in inducing the constriction of the peripheral vessels seen with local exposure to vibration, and that hand-arm vibration may produce an additive effect on the noise-induced TTS. Furthermore, finger skin temperature and finger blood flow were measured simultaneously as indicators of peripheral circulatory movement for five healthy subjects. The relation between the synergistic action of noise and vibration and the participation of the sympathetic nervous system are also discussed.

  18. Hand-arm vibration syndrome from exposure to high-pressure hoses.

    PubMed

    Cooke, R; House, R; Lawson, I J; Pelmear, P L; Wills, M

    2001-09-01

    Hand-arm vibration syndrome has been reported in the literature to occur following exposure to vibration from the use of many tools, but to date there have been no case reports of its occurrence in workers who have used high-pressure hoses, alone or with other tools. To remedy this, the case histories of nine subjects (two without mixed exposure) examined in the UK and Canada are presented, together with their severity classified according to the Stockholm scales. Attention is drawn to the need to use multiple diagnostic tests to establish the diagnosis and the need to implement vibration isolation and damping methodologies, as and when feasible, with respect to hose nozzles in order to minimize the hazard. The ultimate goal for tool manufacturers, hygienists and engineers should be to reduce workplace vibration levels to meet national and international guidelines and legislation, including UK Health & Safety Executive guidelines and European Economic Community directives. The respective risk levels are presented, together with vibration measurements on hoses used by some of the cases.

  19. Effect of Wheelchair Frame Material on Users' Mechanical Work and Transmitted Vibration

    PubMed Central

    Aissaoui, Rachid

    2014-01-01

    Wheelchair propulsion exposes the user to a high risk of shoulder injury and to whole-body vibration that exceeds recommendations of ISO 2631-1:1997. Reducing the mechanical work required to travel a given distance (WN-WPM, weight-normalized work-per-meter) can help reduce the risk of shoulder injury, while reducing the vibration transmissibility (VT) of the wheelchair frame can reduce whole-body vibration. New materials such as titanium and carbon are used in today's wheelchairs and are advertised to improve both parameters, but current knowledge on this matter is limited. In this study, WN-WPM and VT were measured simultaneously and compared between six folding wheelchairs (1 titanium, 1 carbon, and 4 aluminium). Ten able-bodied users propelled the six wheelchairs on three ground surfaces. Although no significant difference of WN-WPM was found between wheelchairs (P < 0.1), significant differences of VT were found (P < 0.05). The carbon wheelchair had the lowest VT. Contrarily to current belief, the titanium wheelchair VT was similar to aluminium wheelchairs. A negative correlation between VT and WN-WPM was found, which means that reducing VT may be at the expense of increasing WN-WPM. Based on our results, use of carbon in wheelchair construction seems promising to reduce VT without increasing WN-WPM. PMID:25276802

  20. Effect of wheelchair frame material on users' mechanical work and transmitted vibration.

    PubMed

    Chénier, Félix; Aissaoui, Rachid

    2014-01-01

    Wheelchair propulsion exposes the user to a high risk of shoulder injury and to whole-body vibration that exceeds recommendations of ISO 2631-1:1997. Reducing the mechanical work required to travel a given distance (WN-WPM, weight-normalized work-per-meter) can help reduce the risk of shoulder injury, while reducing the vibration transmissibility (VT) of the wheelchair frame can reduce whole-body vibration. New materials such as titanium and carbon are used in today's wheelchairs and are advertised to improve both parameters, but current knowledge on this matter is limited. In this study, WN-WPM and VT were measured simultaneously and compared between six folding wheelchairs (1 titanium, 1 carbon, and 4 aluminium). Ten able-bodied users propelled the six wheelchairs on three ground surfaces. Although no significant difference of WN-WPM was found between wheelchairs (P < 0.1), significant differences of VT were found (P < 0.05). The carbon wheelchair had the lowest VT. Contrarily to current belief, the titanium wheelchair VT was similar to aluminium wheelchairs. A negative correlation between VT and WN-WPM was found, which means that reducing VT may be at the expense of increasing WN-WPM. Based on our results, use of carbon in wheelchair construction seems promising to reduce VT without increasing WN-WPM.

  1. Acute effects of vibration from a chipping hammer and a grinder on the hand-arm system.

    PubMed Central

    Kihlberg, S; Attebrant, M; Gemne, G; Kjellberg, A

    1995-01-01

    OBJECTIVES--The purpose of this study was to compare various effects on the hand-arm system of vibration exposure from a chipping hammer and a grinder with the same frequency weighted acceleration. Grip and push forces were measured and monitored during the exposure. The various effects were: muscle activity (measured with surface electrodes), discomfort ratings for different parts of the hand-arm system (made during and after exposure), and vibration perception threshold (for 10 minutes before and 10 minutes after the exposure). RESULTS--No increase in muscle activity due to exposure to vibration was found in the hand muscle studied. In the forearm, conversely, there was an increase in both muscle studied. For the upper arm the muscle activity only increased when exposed to impact vibration. Subjective ratings in the hand and shift in vibration perception threshold were effected more by the grinder than the hammer exposure. CONCLUSION--These results show that the reaction of the hand-arm system to vibration varies with frequency quantitatively as well as qualitatively. They do not support the notion that one single frequency weighted curve would be valid for the different health effects of hand-arm vibration (vascular, musculoskeletal, neurological, and psychophysiological). PMID:8535492

  2. A test rig for the measurement of vibration in hand-held power tools.

    PubMed

    Hansson, J E; Kihlberg, S

    1983-03-01

    The purpose of the present project was to study the possibility of using a test rig for the measurement of vibration and noise from hand-held power tools. A test rig was designed to give the same effect on tool handle vibration as the human hand/arm system. Work was simulated by feeding the material to be processed against the tool, clamped into the rig, with the aid of a co-ordinate table. It was designed for use in studies of impact drills, chain saws, grinders and similar power tools. The report describes a proposal for testing the vibration properties of impact drills. Drilling with the test rig was compared with manual drilling. The difference in the acceleration level between the two methods was about 1 dB for ISO-weighted values in the critical direction. Both methods showed good reproducibility. The possibility of conducting noise level tests of a power tool in the rig was studied and the results are reported separately.

  3. Hand-held percussion machines with low emission of hazardous vibration

    NASA Astrophysics Data System (ADS)

    Sokolov, I. J.; Babitsky, V. I.; Halliwell, N. A.

    2007-09-01

    Vibration and impacts are essential features of many domestic and industrial hand-held machines. In many machines vibration cannot be avoided because of the vibro-impact nature of the working process. The only way to minimise an operator's exposure to harmful vibration in this case is to design the machine rationally. In this paper a percussion machine is considered as a multi-body vibro-impact system. The simplest structures have been found and investigated in which a strong vibro-impact process can be obtained with one body (casing/handle) being free of vibration. Computer simulations using Matlab-Simulink software and initial experiments validate the new approach. The main feature of the proposed new design is the use of a mechanism with zero differential stiffness. A hydro-pneumatic unit with zero stiffness was developed and tested. The new engineering solution was applied to a hydraulic breaker. Even a partial modification of the existing design and effective use of existing hydraulic power source demonstrated a significant improvement in performance.

  4. [Exposure to hand-arm vibrations in orthopaedic plaster room: risk management].

    PubMed

    Lembo, Marco; Lunghi, Alessandro; Leo, Erica; Ritrovato, Matteo; Cannatà, Vittorio; Capussotto, Carlo; Tirabasso, Angelo; Zaffina, Salvatore; Camisa, Vincenzo; Derrico, Pietro; Martella, Mauro; Marchetti, Enrico

    2016-03-24

    In hospitals, the use of vibrating tools, such as oscillating saws to cut plaster, can expose the staff to hand-arm vibrations. The aim of the study was to assess the exposure of workers to vibrations in the plaster room and then  identify the most appropriate  intervention for  prevention and protection to be implemented in order to minimize  exposure and  protect  workers' health, considering different individual hyper-susceptibility conditions. Four different models of plaster saws were examined for the evaluation.  Various measurements were made in normal working conditions of the operators. The values of acceleration and noise detected on the instruments  were  in line with those reported in the literature. The preventive measure adopted (replacing plaster saws currently used in the hospital with similar ones with lower vibration emission) was an adequate means of protection. Health surveillance activities  recorded a higher level of wellbeing, both environmentally and individually and, specifically, an increased protection level for the hyper-susceptibility conditions observed during health checks of exposed personnel  which will be monitored regularly by the Occupational Health Service.

  5. The effects of vibration-reducing gloves on finger vibration

    PubMed Central

    Welcome, Daniel E.; Dong, Ren G.; Xu, Xueyan S.; Warren, Christopher; McDowell, Thomas W.

    2015-01-01

    Vibration-reducing (VR) gloves have been used to reduce the hand-transmitted vibration exposures from machines and powered hand tools but their effectiveness remains unclear, especially for finger protection. The objectives of this study are to determine whether VR gloves can attenuate the vibration transmitted to the fingers and to enhance the understanding of the mechanisms of how these gloves work. Seven adult male subjects participated in the experiment. The fixed factors evaluated include hand force (four levels), glove condition (gel-filled, air bladder, no gloves), and location of the finger vibration measurement. A 3-D laser vibrometer was used to measure the vibrations on the fingers with and without wearing a glove on a 3-D hand-arm vibration test system. This study finds that the effect of VR gloves on the finger vibration depends on not only the gloves but also their influence on the distribution of the finger contact stiffness and the grip effort. As a result, the gloves increase the vibration in the fingertip area but marginally reduce the vibration in the proximal area at some frequencies below 100 Hz. On average, the gloves reduce the vibration of the entire fingers by less than 3% at frequencies below 80 Hz but increase at frequencies from 80 to 400 Hz. At higher frequencies, the gel-filled glove is more effective at reducing the finger vibration than the air bladder-filled glove. The implications of these findings are discussed. Relevance to industry Prolonged, intensive exposure to hand-transmitted vibration can cause hand-arm vibration syndrome. Vibration-reducing gloves have been used as an alternative approach to reduce the vibration exposure. However, their effectiveness for reducing finger-transmitted vibrations remains unclear. This study enhanced the understanding of the glove effects on finger vibration and provided useful information on the effectiveness of typical VR gloves at reducing the vibration transmitted to the fingers. The new

  6. An interpretative phenomenological analysis of the psychological ramifications of hand-arm vibration syndrome.

    PubMed

    Ayers, Beverley; Forshaw, Mark

    2010-05-01

    With a substantial number of individuals diagnosed with Hand-Arm Vibration Syndrome (HAVS) and the preponderance of research focused on the medical and paramedical issues, the psychological and mental health sequelae of HAVS are largely neglected within the published literature. A series of focus groups and interviews were conducted involving nine people who had been diagnosed with HAVS. Transcripts of these interviews were analysed using Interpretative Phenomenological Analysis. Four key themes were identified within the discourse of individuals affected by HAVS: machismo; coping; psychological impacts; and the development of support services for HAVS. Clinical implications are briefly discussed.

  7. Hand-arm vibration syndrome among travertine workers: a follow up study.

    PubMed

    Bovenzi, M; Franzinelli, A; Scattoni, L; Vannuccini, L

    1994-06-01

    In a six year follow up study of the handarm vibration syndrome, 62 stoneworkers operating hand held vibrating tools in 10 travertine quarries and mills were first investigated in 1985 and then in 1991. The frequency weighted acceleration of vibration from the rock drills and stone hammers used by the travertine workers exceeded 20 m/s2, indicating a hazardous work activity according to the proposal of the EC directive for physical agents. A clinical examination and a cold provocation test were repeated with the same procedures as those adopted at the time of the first survey. The stoneworkers were divided into groups according to current work state: active stoneworkers who continued to use powered tools during the follow up (n = 21, median exposure time 22 years), and ex-stoneworkers with retirement vibration free intervals of three years (n = 22, median exposure time 27.5 years) and of six years (n = 19, median exposure time 20 years). In the group of active stoneworkers, a 38% onset a new cases of vibration-induced white finger (VWF) was found during the follow up (p < 0.01). Among the retired stoneworkers affected with VWF (n = 24), one recovered from VWF, one showed improvement, 20 remained stationary, and two deteriorated. The ex-stoneworkers experienced no significant change in sensorineural disturbances and a decrease in musculoskeletal symptoms of the upper limbs. At the cold provocation test, the currently active stoneworkers with VWF showed, on a group basis, a delayed finger rewarming time between the two examinations (p = 0.002). An abnormal response to cold provocation persisted in the fingers of the ex-stoneworkers with VWF, even in those reporting subjective improvement. These findings indicate a tendency towards the irreversibility of sensorineural and VWF symptoms in a group of ex-stoneworkers with prolonged exposure to high vibration levels in the past. The increased occurrence of VWF in the active stone workers after a few extra years of

  8. Anti-vibration gloves?

    PubMed

    Hewitt, Sue; Dong, Ren G; Welcome, Daniel E; McDowell, Thomas W

    2015-03-01

    For exposure to hand-transmitted vibration (HTV), personal protective equipment is sold in the form of anti-vibration (AV) gloves, but it remains unclear how much these gloves actually reduce vibration exposure or prevent the development of hand-arm vibration syndrome in the workplace. This commentary describes some of the issues that surround the classification of AV gloves, the assessment of their effectiveness and their applicability in the workplace. The available information shows that AV gloves are unreliable as devices for controlling HTV exposures. Other means of vibration control, such as using alternative production techniques, low-vibration machinery, routine preventative maintenance regimes, and controlling exposure durations are far more likely to deliver effective vibration reductions and should be implemented. Furthermore, AV gloves may introduce some adverse effects such as increasing grip force and reducing manual dexterity. Therefore, one should balance the benefits of AV gloves and their potential adverse effects if their use is considered.

  9. A method for assessing the effectiveness of anti-vibration gloves using biodynamic responses of the hand arm system

    NASA Astrophysics Data System (ADS)

    Dong, R. G.; Rakheja, S.; McDowell, T. W.; Welcome, D. E.; Wu, J. Z.; Warren, C.; Barkley, J.; Washington, B.; Schopper, A. W.

    2005-04-01

    Anti-vibration gloves are widely used to help minimize hand-arm vibration exposure. In this study, an alternative method is proposed to assess the vibration isolation effectiveness of these gloves using the biodynamic responses of the bare- and gloved-hand-arm system exposed to vibration. The laboratory experiments were performed with a total of five human subjects using a typical anti-vibration air bladder glove subjected to a broad-band random vibration spectrum in conjunction with a specially designed instrumented handle. The measured data were analyzed to derive the biodynamic responses of the bare as well as gloved human hand-arm system in terms of the apparent mass and the mechanical impedance. The two biodynamic responses were applied to estimate the vibration isolation effectiveness of the glove. The validity of the proposed concept was examined by comparing the estimated vibration transmissibility magnitudes of the glove with those obtained using a palm adapter method. The comparison of the results suggests that the proposed method offers a good alternative for estimating glove vibration transmissibility. The measured data and the proposed method based upon the biodynamic responses were further used to investigate the effect of the palm adapter on the vibration transmissibility of the glove. The results suggest that the presence of the palm adapter between the subject's palm and the glove may not alter the basic trends in the transmissibility response, but it would affect the transmissibility magnitudes in the middle- and high-frequency ranges. A distinct advantage of the proposed method is that it eliminates the use of an adapter in assessing the vibration isolation effectiveness of the gloves.

  10. Biomechanical models for vibration feedthrough to hands and head for a semisupine pilot.

    PubMed

    Jex, H R; Magdaleno, R E

    1978-01-01

    A series of tracking experiments under vibration has been carried out on the AMRL/BBV shaker facilities covering three axes of vibration with sinusoidal and random waveforms and different control stick configurations. Based on this and other data, a lumped-parameter biomechanical model has been evolved to suit the needs of aircraft control system designers for the new generation of low-altitude, high-speed bombers and highly maneuverable fighters. This paper shows that measured vibration feedthrough to hands and head can be adequately described by this model when linearized about the appropriate configuration of display, posture, and control. The model includes effects of: semisupine torso; sliding hip, plus rocking chest supported on a compliant buttocks/seat; head bobbing on an articulated neck; upper arm and forearm links plus grip-interface compliance, driven by an active neuromuscular system; elbow rest (optional); and stick "feel system" dynamics. Examples are given of the model's application to predict effects of: a 65 degrees semisupine seat, apparent impedance increase of a control stick under pilot control, and a sliding arm rest.

  11. The effects of vibration-reducing gloves on finger vibration.

    PubMed

    Welcome, Daniel E; Dong, Ren G; Xu, Xueyan S; Warren, Christopher; McDowell, Thomas W

    2014-01-01

    Vibration-reducing (VR) gloves have been used to reduce the hand-transmitted vibration exposures from machines and powered hand tools but their effectiveness remains unclear, especially for finger protection. The objectives of this study are to determine whether VR gloves can attenuate the vibration transmitted to the fingers and to enhance the understanding of the mechanisms of how these gloves work. Seven adult male subjects participated in the experiment. The fixed factors evaluated include hand force (four levels), glove condition (gel-filled, air bladder, no gloves), and location of the finger vibration measurement. A 3-D laser vibrometer was used to measure the vibrations on the fingers with and without wearing a glove on a 3-D hand-arm vibration test system. This study finds that the effect of VR gloves on the finger vibration depends on not only the gloves but also their influence on the distribution of the finger contact stiffness and the grip effort. As a result, the gloves increase the vibration in the fingertip area but marginally reduce the vibration in the proximal area at some frequencies below 100 Hz. On average, the gloves reduce the vibration of the entire fingers by less than 3% at frequencies below 80 Hz but increase at frequencies from 80 to 400 Hz. At higher frequencies, the gel-filled glove is more effective at reducing the finger vibration than the air bladder-filled glove. The implications of these findings are discussed.

  12. Impaired nerve conduction in the carpal tunnel of platers and truck assemblers exposed to hand-arm vibration.

    PubMed

    Nilsson, T; Hagberg, M; Burström, L; Kihlberg, S

    1994-06-01

    The goal of this study was to assess the relative risks of sustaining impaired nerve conduction in the hands among vibration-exposed persons as opposed to nonvibration-exposed referents. In a cross-sectional study design platers and truck assembly workers were contrasted to office workers. The 4-h frequency-weighted vibration was 4.6 m.s-2 and 1.0 m.s-2 for the platers and assemblers, respectively. The ergonomic factors were measured as forced grip time. The conduction velocity, distal latency time, and amplitude of the median nerve were measured for both hands. The sensory nerve conduction velocity was slower in the right hand than in the left. An increased risk of prolonged latency time was found for the platers and assemblers when contrasted to the office workers. The relative risks (rate ratios) of impaired nerve conduction for the carpal tunnel segment varied between 1.4 and 2.0 for the distal latency and between 0.9 and 1.7 for the nerve conduction velocity. The rate ratios were generally higher for the left-hand side than for the right-hand side. The risks were not proportional to either the weighted or unweighted vibration exposure. The contributions from vibration and ergonomic factors to impaired nerve conduction velocity were inseparable in this study. Ergonomic factors such as forceful gripping and extreme positions, apart from vibration exposure, may be strong determinants of impaired nerve conduction in the carpal tunnel area.

  13. Methods for deriving a representative biodynamic response of the hand-arm system to vibration

    NASA Astrophysics Data System (ADS)

    Dong, Ren G.; Welcome, Daniel E.; McDowell, Thomas W.; Wu, John Z.

    2009-09-01

    Vibration-induced biodynamic responses (BR) of the human hand-arm system measured with subjects participating in an experiment are usually arithmetically averaged and used to represent their mean response. The mean BR data reported from different studies are further arithmetically averaged to form the reference mean response for standardization and other applications. The objectives of this study are to clarify whether such a response-based averaging process could significantly misrepresent the characteristics of the original responses, and to identify an appropriate derivation method. The arithmetically averaged response was directly compared with the response derived from a property-based method proposed in this study. Two sets of reported mechanical impedance data measured at the fingers and the palms of the hands were used to derive the models required for the comparison. This study found that the response-based arithmetic averaging could generate some systematic errors. The range of the subjects' natural frequencies in each resonance mode, the mode damping ratio, and the number of subjects participating in the experiment are among the major factors influencing the level of the errors. An effective and practical approach for reducing the potential for error is to increase the number of subjects in the BR measurement. On the other hand, the property-based derivation method can be generally used to obtain the representative response, but it is less efficient than the response-based derivation method.

  14. Measurement of vibrations and evaluation of protective gloves for work with hand-held power tools in industrial settings.

    PubMed

    Milosevic, Matija; McConville, Kristiina M V

    2007-01-01

    This study considers the use of hand-held power tools and the exposure of a large number of employees to hand-arm vibrations in work settings as well as the harmful effects that such exposure has on health and safety. The major objective of the project was the development of a diagnostic device for the detection and monitoring of the vibrations produced during work activities in a natural working environment and to analyze the impact of the vibrations on workers during different work operations. The developed device for vibration monitoring is based on the latest generation MEMS tri-axis accelerometer with a wireless link with the PC station. This study demonstrates the use of the device in evaluating the level of protection that gloves provide concerning the level of vibrations during work operations. The initial evaluation shows that the proposed solution provides an effective multifunctional, low-cost diagnostic device for vibration measurement in natural work settings. Preliminary results indicate that the developed device could be used for health and safety studies, evaluation of protective equipment, and ongoing monitoring in a natural working environment, and in this way may lead to more effective prevention and management of the risks associated with exposure to workplace vibrations.

  15. Establishment of one-axis vibration test system for measurement of biodynamic response of human hand-arm system.

    PubMed

    Shibata, Nobuyuki; Hosoya, Naoki; Maeda, Setsuo

    2008-12-01

    Prolonged exposure to hand-arm vibration (HAV) due to use of hand-held power tools leads to an increased occurrence of symptoms of disorders in the vascular, neurological, and osteo-articular systems of the upper limbs called hand-arm vibration syndrome (HAVS). Biodynamic responses of the hand-arm system to vibration can be suggestive parameters that give us better assessment of exposure to HAV and fundamental data for design of low-vibration-exposure power tools. Recently, a single axis hand-arm vibration system has been installed in the Japan National Institute of Occupational Safety and Health (NIOSH). The aims of this study were to obtain the fundamental dynamic characteristics of an instrumented handle and to validate the performance and measurement accuracy of the system applied to dynamic response measurement. A pseudo-random vibration signal with a frequency range of 5-1,250 Hz and a power spectrum density of 1.0 (m/s2)2/Hz was used in this study. First the dynamic response of the instrumented handle without any weight was measured. After this measurement, the dynamic response measurement of the handle with weights mounted on the handle was performed. The apparent mass of a weight itself was obtained by using the mass cancellation method. The mass of the measuring cap on the instrumented handle was well compensated by using the mass cancellation method. Based on the 10% error tolerance, this handle can reliably measure the dynamic response represented by an apparent mass with a minimum weight of 2.0 g in a frequency range of 10.0 to 1,000 Hz. A marked increase in the AM magnitude of the weights of 15 g and 20 g in frequency ranges greater than 800 Hz is attributed not to the fundamental resonance frequency of the handle with weights, but to the fixation of the weight to the measuring cap. In this aspect, the peak of the AM magnitude can be reduced and hence should not be an obstacle to the biodynamic response measurement of the human hand-arm system. On the

  16. [Effects of exposure to occupational hand-arm vibration on maintenance of postural balance].

    PubMed

    Tanaka, Kazuko; Maeda, Takafumi; Tanaka, Masatoshi; Fukushima, Tetsuhito

    2004-11-01

    In order to determine the relationship between exposure to hand-arm vibration through the use of vibration tools and dysfunction in the maintenance of postural balance, 106 male forestry workers were examined by stabilometry for deflection in the center of gravity and in the air conduction hearing levels. A questionnaire survey was also conducted among the workers in order to obtain details regarding their age, the types of tools used by them, and the duration for which they had used a chain saw. The vibration acceleration of a chain saw has been limited to a level of 3 G or less since 1976 in accordance with the notification from the Japanese Forestry Agency and the Ministry of Labor. In fact, chain saws with significantly reduced vibration acceleration in comparison with those used before 1976 have been available. Therefore, in 2000, we conducted a test on forestry workers who were divided into two groups-workers who had used a chain saw for 25 years or more (25-yr-or-more group) and workers who had used a chain saw for 24 yr or less (24-yr-or-less group). Compared to the 24-yr-or-less group, the 25-yr-or-more group exhibited significantly higher levels of average deflection in the center of gravity, expressed as the enveloped (aENV) and rectangular (aREC) areas, and in the hearing levels at 500, 1000, 2000, 4000 and 8000 Hz. For the aENV, the correlation coefficients revealed significant relationships between the hearing levels at 4,000 Hz, the duration of use of a chain saw, and age. Since the duration of use of a chain saw exhibited a significant relationship with age, it was necessary to eliminate the effect of age on the aENV. Subsequently, we divided all the workers into age groups spanning ten years each (from 20 to 70 yr) and compared the aENV among the same age groups in both the 25-yr-or-more and the 24-yr-or-less groups. The averages of the aENV for each age group were higher in the 25-yr-or-more group than in the 24-yr-or-less group. In particular, a

  17. Different conditions of cold water immersion test for diagnosing hand-arm vibration syndrome.

    PubMed

    Laskar, S; Harada, Noriaki

    2005-11-01

    The cold water immersion test with finger skin temperature (FST) measurement is used to assess vascular disorders in hand-arm vibration syndrome (HAVS). The test method is currently being standardized within the International Organization for Standardization (ISO) in which a water temperature of 12°C for 5 min of hand immersion and an option of using a waterproof hand covering during immersion are proposed. It is necessary to evaluate the diagnostic significance of the test with FST measurement under different conditions to provide a proper management of HAVS patients. The aim of this article is to review research findings of this test with FST measurement and discuss test conditions influencing the results and diagnostic significance.Different conditions were employed, and the test results were shown to be influenced by water temperature, immersion time and other conditions such as room temperature, season, ischemia during immersion, and evaluation parameters. These factors need to be considered in the standardization of the cold water immersion test with FST measurement. It has been mentioned that a high water temperature, a short immersion time and other conditions should be chosen to expose a subject to minimal suffering during the test. A water temperature between 10°C and 15°C and a 5 min immersion might be suitable for the cold water immersion test. The reported sensitivity and specificity evaluating rewarming to the initial temperature for the test using a water temperature of 12°C and a 3 min immersion are 58% and 100%, respectively; these are low but similar to those for tlie water immersion test at 10°C. Therefore, the proposed cold water immersion test at 12°C for 5 min by the ISO (Draft International Standard) is the focus of much interest, and further studies are needed to obtain sufficient data for evaluating the diagnostic significance of the test. At present, the test needs to be used together with a test battery.

  18. Perceptual Space of Superimposed Dual-Frequency Vibrations in the Hands.

    PubMed

    Hwang, Inwook; Seo, Jeongil; Choi, Seungmoon

    2017-01-01

    The use of distinguishable complex vibrations that have multiple spectral components can improve the transfer of information by vibrotactile interfaces. We investigated the qualitative characteristics of dual-frequency vibrations as the simplest complex vibrations compared to single-frequency vibrations. Two psychophysical experiments were conducted to elucidate the perceptual characteristics of these vibrations by measuring the perceptual distances among single-frequency and dual-frequency vibrations. The perceptual distances of dual-frequency vibrations between their two frequency components along their relative intensity ratio were measured in Experiment I. The estimated perceptual spaces for three frequency conditions showed non-linear perceptual differences between the dual-frequency and single-frequency vibrations. A perceptual space was estimated from the measured perceptual distances among ten dual-frequency compositions and five single-frequency vibrations in Experiment II. The effect of the component frequency and the frequency ratio was revealed in the perceptual space. In a percept of dual-frequency vibration, the lower frequency component showed a dominant effect. Additionally, the perceptual difference among single-frequency and dual-frequency vibrations were increased with a low relative difference between two frequencies of a dual-frequency vibration. These results are expected to provide a fundamental understanding about the perception of complex vibrations to enrich the transfer of information using vibrotactile stimuli.

  19. Perceptual Space of Superimposed Dual-Frequency Vibrations in the Hands

    PubMed Central

    Seo, Jeongil; Choi, Seungmoon

    2017-01-01

    The use of distinguishable complex vibrations that have multiple spectral components can improve the transfer of information by vibrotactile interfaces. We investigated the qualitative characteristics of dual-frequency vibrations as the simplest complex vibrations compared to single-frequency vibrations. Two psychophysical experiments were conducted to elucidate the perceptual characteristics of these vibrations by measuring the perceptual distances among single-frequency and dual-frequency vibrations. The perceptual distances of dual-frequency vibrations between their two frequency components along their relative intensity ratio were measured in Experiment I. The estimated perceptual spaces for three frequency conditions showed non-linear perceptual differences between the dual-frequency and single-frequency vibrations. A perceptual space was estimated from the measured perceptual distances among ten dual-frequency compositions and five single-frequency vibrations in Experiment II. The effect of the component frequency and the frequency ratio was revealed in the perceptual space. In a percept of dual-frequency vibration, the lower frequency component showed a dominant effect. Additionally, the perceptual difference among single-frequency and dual-frequency vibrations were increased with a low relative difference between two frequencies of a dual-frequency vibration. These results are expected to provide a fundamental understanding about the perception of complex vibrations to enrich the transfer of information using vibrotactile stimuli. PMID:28081187

  20. Effect of handle size and hand-handle contact force on the biodynamic response of the hand-arm system under z h-axis vibration

    NASA Astrophysics Data System (ADS)

    Marcotte, P.; Aldien, Y.; Boileau, P.-É.; Rakheja, S.; Boutin, J.

    2005-05-01

    The influences of the handle size and of the hand forces exerted on a vibrating tool handle on the driving-point mechanical impedance (DPMI) response of the human hand-arm system have been investigated through laboratory measurements performed on seven adult male subjects. Measurements were performed with three instrumented cylindrical handles with different diameters (30, 40 and 50 mm) exposed to two different levels of broadband random vibration (2.5 and 5.0 m/s 2) along the z h axis, while the variations in the hand forces were realized through nine different combinations of grip (10, 30 and 50 N) and push (25, 50 and 75 N) forces. The static hand-handle contact forces were also evaluated for each combination of grip and push forces, and each handle size through measurements of pressure distribution at the hand-handle interface. The results have shown that the average contact force is a linear combination of the push and grip forces, while the contribution due to grip force is considerably larger than the push force and dependent upon the handle size. The hand-handle coupling force, as defined in ISO/WD-15230, was further evaluated by summing the grip and push forces, which is independent of the handle size. The results have shown that the DPMI magnitude tends to increase with an increase in both the grip and push forces at frequencies above 25 Hz, while the increase in DPMI magnitude was better correlated with the coupling force below 200 Hz. A better correlation with the contact force, however, was attained at frequencies above 200 Hz, suggesting a stronger dependence on the grip force at higher frequencies. The DPMI magnitude response was also found to be influenced by the handle diameter. Increasing the handle size yielded higher peak DPMI magnitude response, specifically under medium to high hand-handle coupling forces (30 N grip and 50 N push; 50 N grip and 75 N push).

  1. Influence of tyre inflation pressure on whole-body vibrations transmitted to the operator in a cut-to-length timber harvester.

    PubMed

    Sherwin, L M; Owende, P M O; Kanali, C L; Lyons, J; Ward, S M

    2004-05-01

    The influence of tyre inflation pressure on whole-body vibrations transmitted to the operator during the movement of a cut-to-length timber harvester was evaluated. Vibration measurements were taken in three orthogonal (x, y, z) axes at tyre pressure settings of 138, 345 and 414 kPa. Vibration was predominant in the vertical (z) direction with the peak rms acceleration value for the operator seat (0.281 ms(-2)) occurring at approximately 3.2 Hz. The corresponding peak value for the operator cabin chassis was 0.425 m s(-2) at 4 Hz. At 414 kPa, there was potential health risk on the operator for exposures above 8h duration. The vibration total values recorded for the operator seat at the maximum tyre inflation pressure setting were classed as "fairly uncomfortable" (ISO standard 2631-1), and vertical seat vibration transmissibility was highest between 4 and 8 Hz at the 345 kPa tyre pressure setting. The recorded values of WBV were significantly reduced by a reduction in tyre inflation pressure which may therefore be used to moderate the magnitude of WBV on wheeled timber harvesters.

  2. A non-resonant, frequency up-converted electromagnetic energy harvester from human-body-induced vibration for hand-held smart system applications

    NASA Astrophysics Data System (ADS)

    Halim, Miah A.; Park, Jae Y.

    2014-03-01

    We present a non-resonant, frequency up-converted electromagnetic energy harvester that generates significant power from human-body-induced vibration, e.g., hand-shaking. Upon excitation, a freely movable non-magnetic ball within a cylinder periodically hits two magnets suspended on two helical compression springs located at either ends of the cylinder, allowing those to vibrate with higher frequencies. The device parameters have been designed based on the characteristics of human hand-shaking vibration. A prototype has been developed and tested both by vibration exciter (for non-resonance test) and by manual hand-shaking. The fabricated device generated 110 μW average power with 15.4 μW cm-3 average power density, while the energy harvester was mounted on a smart phone and was hand-shaken, indicating its ability in powering portable hand-held smart devices from low frequency (<5 Hz) vibrations.

  3. Associations of work activities requiring pinch or hand grip or exposure to hand-arm vibration with finger and wrist osteoarthritis: a meta-analysis.

    PubMed

    Hammer, Paula E C; Shiri, Rahman; Kryger, Ann I; Kirkeskov, Lilli; Bonde, Jens Peter

    2014-03-01

    We systematically reviewed the epidemiologic evidence linking finger and wrist osteoarthritis (OA) with work activities requiring pinch or hand grip or exposure to hand-arm vibration (HAV). PubMed and Embase databases were searched up to June 2013. We selected studies assessing the associations of radiographic diagnosed finger and/or wrist joint OA with work activities involving pinch or hand grip or exposure to HAV. We used specific criteria to evaluate completeness of reporting, potential confounding, and bias. Pooled odds ratios (OR) were computed using random-effects meta-analyses. Of the 19 studies included, 17 were cross-sectional, 1 was a prospective cohort, and 1 a case-control study. The meta-analyses of studies that controlled their estimates for at least age and gender showed the associations of pinch grip work with proximal interphalangeal joint [OR 1.56, 95% confidence interval (95% CI) 1.09-2.23] and the first carpometacarpal joint OA (OR 2.10, 95% CI 1.06-4.17), but not with distal interphalangeal, metacarpalphalangeal, or wrist joints OA. Hand grip work and exposure to HAV were not associated with any finger or wrist OA. Epidemiological studies provide limited evidence that pinch grip may increase the risk of wrist or finger OA, but causal relation cannot be resolved because of cross-sectional designs and inadequate characterization of biomechanical strain to the hand and wrist.

  4. Self-reported cold sensitivity in normal subjects and in patients with traumatic hand injuries or hand-arm vibration syndrome

    PubMed Central

    2010-01-01

    Background Cold sensitivity is a common and disabling complaint following hand injuries. The main purpose of this study was to describe self-reported consequences of cold sensitivity and the association with disability and health-related quality of life in patients with hand injuries or hand-arm vibration syndrome (HAVS) and in normal subjects. Methods Responses to the Cold Intolerance Symptom Severity (CISS) questionnaire, Potential Work Exposure Scale (PWES), Disability of the Arm, Shoulder and Hand (DASH) and Short-Form 36 questionnaire (SF-36) were investigated in normal subjects (n = 94), hand injured patients (amputation and nerve injuries, n = 88) and patients with HAVS (n = 30). The results are presented as median (range), percent and mean deviation from norms. The Kruskal Wallis Test or Mann-Whitney U-Test were used to identify significant differences between multiple groups or subgroups. The Spearman rank correlation was used to study the relationship between cold sensitivity and disability. Results Abnormal cold sensitivity (CISS score > 50) was seen in 75% and 45% of patients with HAVS and a traumatic hand injury, respectively. Patients were significantly more exposed to cold in their work environment than the normal population, with a consequently negative effect on work ability due to cold sensitivity. Patients with abnormal cold sensitivity were more seriously disabled and had a poorer health-related quality of life than patients with normal cold sensitivity [higher DASH scores and e.g. significantly larger mean deviation from norms in the subscales Role Physical and Bodily Pain (SF-36)]. Conclusion Severe and abnormal cold sensitivity may have a profound impact on work capacity, leisure, disability and health-related quality of life. It is frequently seen in patients with traumatic hand injuries and particularly apparent in patients with HAVS. PMID:20462418

  5. Review and Evaluation of Hand–Arm Coordinate Systems for Measuring Vibration Exposure, Biodynamic Responses, and Hand Forces

    PubMed Central

    Dong, Ren G.; Sinsel, Erik W.; Welcome, Daniel E.; Warren, Christopher; Xu, Xueyan S.; McDowell, Thomas W.; Wu, John Z.

    2015-01-01

    The hand coordinate systems for measuring vibration exposures and biodynamic responses have been standardized, but they are not actually used in many studies. This contradicts the purpose of the standardization. The objectives of this study were to identify the major sources of this problem, and to help define or identify better coordinate systems for the standardization. This study systematically reviewed the principles and definition methods, and evaluated typical hand coordinate systems. This study confirms that, as accelerometers remain the major technology for vibration measurement, it is reasonable to standardize two types of coordinate systems: a tool-based basicentric (BC) system and an anatomically based biodynamic (BD) system. However, these coordinate systems are not well defined in the current standard. Definition of the standard BC system is confusing, and it can be interpreted differently; as a result, it has been inconsistently applied in various standards and studies. The standard hand BD system is defined using the orientation of the third metacarpal bone. It is neither convenient nor defined based on important biological or biodynamic features. This explains why it is rarely used in practice. To resolve these inconsistencies and deficiencies, we proposed a revised method for defining the realistic handle BC system and an alternative method for defining the hand BD system. A fingertip-based BD system for measuring the principal grip force is also proposed based on an important feature of the grip force confirmed in this study. PMID:26929824

  6. Lateral displacement of a Gaussian beam transmitted through a one-dimensional left-handed meta-material slab

    NASA Astrophysics Data System (ADS)

    Zhong, Yu; Ran, Lixin; Cheng, Xiangxiang; Kong, Jin Au

    2006-02-01

    In this paper, the transmission of a Gaussian beam passing through a slab made of a one-dimensional left-handed meta-material (1D LHM) is studied. The analytical solution of the electric and the magnetic fields inside and outside the slab are given. The calculation of the power flow of the beam predicts that in the negative pass band of the 1D LHM, there exist different directions of lateral displacements. Such phenomenon is further verified by experiment.

  7. Research into hand-arm vibration syndrome and its prevention in Japan.

    PubMed

    Yamada, S; Sakakibara, H

    1994-05-01

    Research on vibration syndrome in Japan began in the 1930s with studies of the disorder among railway, mining and shipyard workers. In 1947, the Ministry of Labor decided vibration syndrome among operators of rock drills and riveters etc. was an occupational disease. Industrial developments in the 1950s and 1960s promoted the survey of vibration syndrome in mining, stone quarrying and forestry. The Ministry of Labor (1965) and the National Personnel Agency (1966) legally recognized vibration syndrome among chain saw operators as an occupational disease. Guidelines for prevention and early therapy were issued in the 1970s and 80s. From the late 1970s into the 1980s, research focused on the clinical picture, diagnostic methods and therapy. In pathophysiology, advances were made in research into the autonomic nervous system during the 1980s. The 1970s and 80s saw a steady reduction in risk from technological change and working conditions, and advances in medical care, education and meteorological forecasting. A comprehensive prevention system established in the 1980s in the Japanese forest industry involved: 1) work restrictions, 2) an improved health care system, 3) advances in the design of vibrating tools, handle-warming devices, and 4) improved worker education. This comprehensive preventive system was legally introduced into other industries, resulting in a rapid decrease in the incidence of vibration syndrome in Japan.

  8. Cross sectional study of a workforce exposed to hand-arm vibration: with objective tests and the Stockholm workshop scales

    PubMed Central

    McGeoch, K.; Gilmour, W

    2000-01-01

    component while years of tool use and trade were the variables most associated with vascular damage. (3) The prevalence of neurological symptoms (62%) was greater than the prevalence of vascular symptoms (33%). (4) Dressers and welders have shorter latent periods than platers and fitters.


Keywords: hand-arm vibration syndrome; neurological objective tests PMID:10711267

  9. Current perception threshold for assessment of the neurological components of hand-arm vibration syndrome: a review.

    PubMed

    Kurozawa, Youichi; Hosoda, Takenobu; Nasu, Yoshiro

    2010-09-01

    Current perception threshold (CPT) has been proposed as a quantitative method for assessment of peripheral sensory nerve function. The aim of this review of selected reports is to provide an overview of CPT measurement for the assessment of the neurological component of hand-arm vibration syndrome (HAVS). The CPT values at 2000 Hz significantly increased for patients with HAVS. This result supports the previous histological findings that demyelination is found predominantly in the peripheral nerves in the hands of men exposed to hand-arm vibration. Diagnostic sensitivity and specificity were high for severe cases of Stockholm sensorineural (SSN) stage 3 compared with non-exposed controls, but not high for mild cases of SSN stage 1 or 2 and for carpal tunnel syndrome associated with HAVS. However, there are only a few studies on the diagnostic validity of the CPT test for the neurological components of HAVS. Further research is needed and should include diagnostic validity and standardizing of measurement conditions such as skin temperature.

  10. Self-reported cold sensitivity in patients with traumatic hand injuries or hand-arm vibration syndrome - an eight year follow up

    PubMed Central

    2014-01-01

    Background Cold sensitivity is a common complaint following hand injuries. Our aim was to investigate long-term self-reported cold sensitivity, and its predictors and the importance of sense of coherence (SOC), 8 years after a hand injury as well as in patients treated for Hand Arm Vibration Syndrome (HAVS) during the same time period. Methods Responses to the Cold Intolerance Symptom Severity (CISS) questionnaire and the Sense of Coherence (SOC) questionnaire were investigated in hand injured patients (n = 64) and in patients with HAVS (n = 26). The Mann–Whitney U-Test was used to identify significant differences between subgroups. When analysing predictors for cold sensitivity severity, the Spearman rank correlation (rS coefficient) were used for quantitative predictive variables, Mann–Whitney U-Test for dichotomous variables and Kruskal-Wallis Test for multiple categorical data. The Wilcoxon´s signed rank test was used to investigate longitudinal changes in outcome. Results There was a significant change in total CISS score for patients with traumatic hand injury, indicating fewer problems with cold sensitivity over time. Symptoms, such as stiffness, weakness and skin colour change on cold exposure, caused fewer problems, but perceived pain/aching and numbness remained unchanged as well as time needed for relief of symptoms on return to a warm environment. The negative impact of cold sensitivity on daily activities and at work was reduced, but problems when engaged in hobbies or when being exposed to cold wintry weather remained unchanged. None of the investigated predictors related to the hand injury were significantly associated with a change in cold sensitivity at the 8-year follow up. In contrast, no significant change in cold sensitivity was noted in the patients with HAVS for any of the situations included in the CISS questionnaire. A lower sense of coherence score correlated significantly with worse cold sensitivity (CISS score) in both

  11. Self-reported cold sensitivity in patients with traumatic hand injuries or hand-arm vibration syndrome - an eight year follow up.

    PubMed

    Carlsson, Ingela K; Dahlin, Lars B

    2014-03-14

    Cold sensitivity is a common complaint following hand injuries. Our aim was to investigate long-term self-reported cold sensitivity, and its predictors and the importance of sense of coherence (SOC), 8 years after a hand injury as well as in patients treated for Hand Arm Vibration Syndrome (HAVS) during the same time period. Responses to the Cold Intolerance Symptom Severity (CISS) questionnaire and the Sense of Coherence (SOC) questionnaire were investigated in hand injured patients (n = 64) and in patients with HAVS (n = 26). The Mann-Whitney U-Test was used to identify significant differences between subgroups. When analysing predictors for cold sensitivity severity, the Spearman rank correlation (rS coefficient) were used for quantitative predictive variables, Mann-Whitney U-Test for dichotomous variables and Kruskal-Wallis Test for multiple categorical data. The Wilcoxon's signed rank test was used to investigate longitudinal changes in outcome. There was a significant change in total CISS score for patients with traumatic hand injury, indicating fewer problems with cold sensitivity over time. Symptoms, such as stiffness, weakness and skin colour change on cold exposure, caused fewer problems, but perceived pain/aching and numbness remained unchanged as well as time needed for relief of symptoms on return to a warm environment. The negative impact of cold sensitivity on daily activities and at work was reduced, but problems when engaged in hobbies or when being exposed to cold wintry weather remained unchanged. None of the investigated predictors related to the hand injury were significantly associated with a change in cold sensitivity at the 8-year follow up. In contrast, no significant change in cold sensitivity was noted in the patients with HAVS for any of the situations included in the CISS questionnaire. A lower sense of coherence score correlated significantly with worse cold sensitivity (CISS score) in both patient groups. The negative impact of cold

  12. Hand-arm vibration in the aetiology of hearing loss in lumberjacks.

    PubMed Central

    Pyykkö, I; Starck, J; Färkkilä, M; Hoikkala, M; Korhonen, O; Nurminen, M

    1981-01-01

    A longitudinal study of hearing loss was conducted among a group of lumberjacks in the years 1972 and 1974--8. The number of subjects increased from 72 in 1972 to 203 in 1978. They were classified according to (1) a history of vibration-induced white finger (VWF), (2) age, (3) duration of exposure, an (4) duration of ear muff usage. The hearing level at 4000 Hz was used to indicate the noise-induced permanent threshold shift (NIPTS). The lumberjacks were exposed, at their present pace of work, to noise, Leq values 96-103 dB(A), and to the vibration of a chain saw (linear acceleration 30-70 ms-2). The chain saws of the early 1960s were more hazardous, with the average noise level of 111 dB(A) and a variation acceleration of 60-180 ms-2. When classified on the basis of age, the lumberjacks with VWF had about a 10 dB greater NIPTS than subjects without VWF. NIPTS increased with the duration of exposure to chain saw noise, but with equal noise exposure the NIPTS was about 10 dB greater in lumberjacks with VWF than without VWF. With the same duration of ear protection the lumberjacks with VWF consistently had about a 10 dB greater NIPTS than those without VWF. The differences in NIPTS were statistically significant. The possible reason for more advanced NIPTS in subjects with VWF is that vibration might operate in both of these disorders through a common mechanism--that is, producing a vasoconstriction in both cochlear and digital blood vessels as a result of sympathetic nervous system activity. PMID:7272242

  13. Review of different quantification methods for the diagnosis of digital vascular abnormalities in hand-arm vibration syndrome.

    PubMed

    Mahbub, Mh; Harada, Noriaki

    2011-01-01

    This study was undertaken to review the diagnostic ability of different quantification methods in the assessment of vibration-induced white finger (VWF), the typical clinical manifestation of vascular injuries in Hand-arm Vibration Syndrome (HAVS). A literature search of original and major review articles related to the quantification techniques for diagnosing vascular injuries in HAVS was performed. Relevant data from the publications were extracted and included in this study for reporting and discussion. Few studies were available to substantiate the diagnostic techniques using the nail press test and nailfold capillaroscopy. Also, few studies were found to conclusively demonstrate the diagnostic ability using thermometry and thermography incorporated with cold provocation. Some recent reports raised the question regarding the diagnostic ability of finger plethysmography; but by virtue of its comparable assessment parameters and better diagnostic performance, plethysmography appears to be a suitable diagnostic method. In noninvasive quantification of vascular injuries, diagnostic techniques like laser Doppler perfusion imaging and nailfold capillaroscopy require further evaluation in future studies. For a reliable objective diagnosis of VWF at present, quantification of vascular responses using a test battery including established methods like thermometry or thermography and strain gauge plethysmography appears to be useful.

  14. [Study on the effects of walking on functional fitness in aged patients with the hand-arm vibration syndrome].

    PubMed

    Kurosawa, Y; Kato, T; Hosoda, T; Morita, H; Ohshiro, H; Nose, T

    2001-11-01

    This article reports the effectiveness of mild walking exercise for maintaining functional fitness in aged patients with the hand-arm vibration syndrome (HAVS). Fifty-two patients suffering from vibration syndrome, for which they received annual compulsory examination from December 1998 to March 1999 at the San-in Rosai Hospital, were examined. They all were male, with a mean age (standard deviation) of 69.1 (7.3) years, and were randomly allocated to an intervention group (N = 26) and a control group (N = 26). The goal of the intervention was to achieve and maintain at least 30 minutes of walking a day. Functional fitness was assessed by a sitting and standing test, a zigzag walking test, a hand working test with a pegboard for dexterity, and a self-care working test proposed by the Physical Fitness Research Institute, Meiji Life Foundation of Health and Welfare. There were no significant differences between the two groups regarding baseline characteristics. The proportions of subjects with regular exercise habits after the intervention were 84.6% (22/26) and 53.8% (14/26) in the intervention and control groups, respectively, the difference being significant. The total scores for functional fitness were improved in the intervention, while decline was noted in the control group. Sitting and standing and self-care working ability were also improved in the intervention group as against the deterioration with age in the control group. Our findings show to some extent that intervention using mild exercise, walking for 30 min, is effective for aged patients with HAVS to maintain and improve functional fitness.

  15. Incidence and Predictors of Hand-Arm Musculoskeletal Complaints among Vibration-exposed African Cassava and Corn Millers.

    PubMed

    Mbutshu, Lukuke Hendrick; Malonga, Kaj Francoise; Ngatu, Nlandu Roger; Kanbara, Sakiko; Longo-Mbenza, Benjamin; Suganuma, Narufumi

    2014-09-01

    Cassava and corn milling is a growing small-scale enterprise in Africa. We aimed to determine the incidence of hand-arm musculoskeletal complaints among vibration-exposed Congolese cassava and corn millers in the previous 12 months. A cross-sectional study was conducted, prior to a follow-up study, from March to May 2013 among cassava/corn millers in Lubumbashi, Democratic Republic of Congo, in which 365 millers age-matched to 365 civil workers anonymously answered a questionnaire. Overall incidence of hand-arm musculoskeletal complaints was 25.8% in millers (vs. 5.2% in civil workers; p < 0.001). The risk of experiencing musculoskeletal symptoms was seven times higher in millers [vs. civil workers; odds ratio (OR) = 7.10; 95% confidence interval (CI): 4.03-12.50; p < 0.0001]; 2.4 times higher in smoking millers (vs. smoking civil office workers; OR = 2.36; 95% CI: 1.42-3.88; p < 0.001); 3.6 times higher in millers with longer daily exposure (> 8 hours; vs. those working ≤ 8 hours; OR = 3.56; 95% CI: 1.93-3.61; p = 0.026); and 7.4 times higher in young millers (vs. older millers, OR = 7.39; 95% CI: 1.29-75.52; p < 0.001). Smoking, number of cigarettes, and daily exposure duration were positively correlated with musculoskeletal complaints. This study revealed a relatively high incidence of musculoskeletal complaints among African cassava and corn millers. The use of anti-vibration protective equipment and the regulation of this hazardous occupation may reduce the burden of musculoskeletal disorders in millers.

  16. Hand-arm vibration and the risk of vascular and neurological diseases—A systematic review and meta-analysis

    PubMed Central

    Wahlström, Jens; Burström, Lage

    2017-01-01

    Background Increased occurrence of Raynaud’s phenomenon, neurosensory injury and carpal tunnel syndrome has been reported for more than 100 years in association with work with vibrating machines. The current risk prediction modelling (ISO-5349) for “Raynaud’s phenomenon” is based on a few studies published 70 to 40 years ago. There are no corresponding risk prediction models for neurosensory injury or carpal tunnel syndrome, nor any systematic reviews comprising a statistical synthesis (meta-analysis) of the evidence. Objectives Our aim was to provide a systematic review of the literature on the association between Raynaud’s phenomenon, neurosensory injuries and carpal tunnel syndrome and hand-arm vibration (HAV) exposure. Moreover the aim was to estimate the magnitude of such an association using meta-analysis. Methods This systematic review covers the scientific literature up to January 2016. The databases used for the literature search were PubMed and Science Direct. We found a total of 4,335 abstracts, which were read and whose validity was assessed according to pre-established criteria. 294 articles were examined in their entirety to determine whether each article met the inclusion criteria. The possible risk of bias was assessed for each article. 52 articles finally met the pre-established criteria for inclusion in the systematic review. Results The results show that workers who are exposed to HAV have an increased risk of vascular and neurological diseases compared to non-vibration exposed groups. The crude estimate of the risk increase is approximately 4–5 fold. The estimated effect size (odds ratio) is 6.9 for the studies of Raynaud’s phenomenon when including only the studies judged to have a low risk of bias. The corresponding risk of neurosensory injury is 7.4 and the equivalent of carpal tunnel syndrome is 2.9. Conclusion At equal exposures, neurosensory injury occurs with a 3-time factor shorter latency than Raynaud’s phenomenon. Which

  17. A prospective cohort study investigating an exposure-response relationship among vibration-exposed male workers with numbness of the hands.

    PubMed

    Edlund, Maria; Burström, Lage; Gerhardsson, Lars; Lundström, Ronnie; Nilsson, Tohr; Sandén, Helena; Hagberg, Mats

    2014-03-01

    The aim of this study was to investigate the exposure-response relationship of hand-arm vibration exposure to neurological symptoms (numbness) of the hand in a cohort of vibration-exposed workers. The baseline cohort comprised 241 office and manual workers with and without exposure to hand-arm vibration. Numbness (the symptom or event) in the hand was assessed for all subjects at baseline and follow-ups after 5, 10, and 16 years. The workers were stratified into quartiles with no exposure in the first quartile and increasing intensity of exposure in quartiles 2-4 (groups 1-3). Data analysis was performed using survival analysis (time to event). Information on cumulative exposure and years of exposure to event was collected via questionnaires. Measurements were performed in accordance with the International Organization for Standardization (ISO) 5349-1. The hazard ratio (HR) of risk of event (numbness) differed statistically significantly between the non-exposed group (group 0) and the two higher exposure groups (groups 2 and 3). There was also a significant ratio difference between the lowest exposure group (group 1) and the two higher groups. The ratio for group 1 was 1.77 [95% confidence interval (95% CI) 0.96-3.26] compared with 3.78 (95% CI 2.15-6.62) and 5.31 (95% CI 3.06-9.20) for groups 2 and 3, respectively. The results suggest a dose-response relationship between vibration exposure and numbness of the hands. This underlines the importance of keeping vibration levels low to prevent neurological injury to the hands.

  18. Carpal tunnel syndrome in association with hand-arm vibration syndrome: a review of claimants seeking compensation in the Mining Industry.

    PubMed

    Burke, F D; Lawson, I J; McGeoch, K L; Miles, J N V; Proud, G

    2005-05-01

    Twenty six thousand eight hundred and forty-two miners seeking compensation were clinically assessed for vascular and neurosensory impairment arising from exposure to occupational hand-arm vibration (Hand-Arm Vibration Syndrome). They were also assessed clinically for Carpal Tunnel Syndrome which, if present, would result in additional compensation. Fifteen per cent were assessed as having both HAVS and CTS. Thirty-eight per cent of claimants had nocturnal wakening, 1.3% wasting of abductor pollicis brevis, 15% had a positive Tinel's test and 20% had a positive Phalen's test. The 15% prevalence reported is lower than the rates cited previously in several small population studies of workers exposed to vibration. This paper reports the results of the assessment process and discusses the difficulty of discriminating Carpal Tunnel Syndrome from diffuse neurosensory impairment arising from HAVS.

  19. The sensitivity and specificity of thermometry and plethysmography in the assessment of hand-arm vibration syndrome.

    PubMed

    Thompson, Aaron; House, Ron; Manno, Michael

    2008-05-01

    Finger plethysmography and thermometry are objective measures used to assess the vascular aspect of hand-arm vibration syndrome (HAVS). Research to date shows poor correlation between these tests and Stockholm Workshop Scale (SWS) vascular stage. Clinicians, researchers and compensation boards require objective means to diagnose and quantify HAVS. To define the specificity and sensitivity of thermometry and plethysmography using the SWS as the reference criterion. A secondary goal was to consider cut points for the tests optimizing sensitivity and specificity. A cross-sectional analysis was conducted on HAVS patients seen at an occupational medicine specialty clinic. Plethysmography and thermometry were analyzed using SWS vascular stage as the outcome variable. Logistic regression controlled for age, smoking and time since last vibration exposure and use of vasoactive medications. The sensitivity and specificity of the combined tests were calculated using varying cut points. A total of 139 patients consented to participate in the study. Plethysmography stage 1 or greater showed the highest sensitivity (sensitivity 94% and specificity 15%). Specificity was optimized combining plethysmography stage 3 and thermometry stage 3 (specificity 98% and sensitivity 23%). Maximal diagnostic accuracy was achieved by plethysmography alone setting the criteria for a positive test as being stage 1 or greater (70%). Neither plethysmography nor thermometry either alone or in combination demonstrated sufficient sensitivity and specificity to serve as an objective correlate for SWS vascular stage. All combinations of plethysmography and thermometry showed a lower specificity than sensitivity indicating that the SWS may be less sensitive in detecting vascular pathology than the objective tests.

  20. [Occupational therapy for work-related damage induced by mechanical vibration].

    PubMed

    Foti, C; Ciocchetti, E; Antignani, E; Pitruzzella, M; Laurini, A

    2010-01-01

    Vibrations are defined as repeated oscillatory movements of a body; they can be transmitted by contact to humans. From the point of view of physics, vibrations can be differentiated on the basis of frequency, wavelength, amplitude of the oscillation, velocity and acceleration. As far as concerns occupational hazards, two risk factors have been identified: the first involves low frequency vibrations (vehicle drivers), while the second involves high frequency vibrations (manual percussion tools). The transmission of vibration energy can be localized or generalized. Tertiary prevention of exposure to vibrations is based on the use of anti-vibration gloves (for vibrations of the hand and arm) and on anti-vibration shoes (for vibrations of the whole body). The damage caused by vibrations is due to reduced blood circulation and mechanical stimulation in the joints exposed.

  1. Effective information campaign for management of exposure to hand-arm vibration in the metal and construction industries.

    PubMed

    Sauni, Riitta; Toivio, Pauliina; Esko, Toppila; Pääkkönen, Rauno; Uitti, Jukka

    2015-01-01

    European Directive 2002/44/EC defines employers' responsibilities in the risk management of hand-arm vibration (HAV). However, the directive is still not completely implemented in all risk industries. The aim of our study was to determine whether it is possible to improve the recognition and management of the risks of HAV at workplaces with a one-year information campaign. A questionnaire on opinions and measures for controlling HAV exposure at workplaces was sent to all occupational safety representatives and occupational safety managers in the construction and metal industry in Finland (n=1887) and once again to those who responded to the first questionnaire (n=961) one year after the campaign. The campaign increased recognition of HAV in risk assessment from 57.0% to 68.3% (p=.001), increased measures to decrease exposure to HAV from 54.6% to 64.2% (p=.006) and increased the number of programmes to control the risks due to HAV (p<.001). The information campaign, which focuses on the construction and metal industries, proved to be effective in increasing the awareness of the risks of HAV and the measures needed to control exposure to HAV. A similar campaign can be recommended in the case of risks specific to certain occupations.

  2. Transmission of vibration through gloves: effects of material thickness.

    PubMed

    Md Rezali, Khairil Anas; Griffin, Michael J

    2016-08-01

    It might be assumed that increasing the thickness of a glove would reduce the vibration transmitted to the hand. Three material samples from an anti-vibration glove were stacked to produce three thicknesses: 6.4, 12.8 and 19.2 mm. The dynamic stiffnesses of all three thicknesses, the apparent mass at the palm and the finger and the transmission of vibration to the palm and finger were measured. At frequencies from 20 to 350 Hz, the material reduced vibration at the palm but increased vibration at the finger. Increased thickness reduced vibration at the palm but increased vibration at the finger. The measured transmissibilities could be predicted from the material dynamic stiffness and the apparent mass of the palm and finger. Reducing the dynamic stiffness of glove material may increase or decrease the transmission of vibration, depending on the material, the frequency of vibration and the location of measurement (palm or finger). Practitioner Summary: Transmission of vibration through gloves depends on the dynamic response of the hand and the dynamic stiffness of glove material, which depends on material thickness. Measuring the transmission of vibration through gloves to the palm of the hand gives a misleading indication of the transmission of vibration to the fingers.

  3. The Efficacy of Anti-vibration Gloves

    PubMed Central

    Hewitt, Sue; Dong, Ren; McDowell, Tom; Welcome, Daniel

    2016-01-01

    Anyone seeking to control the risks from vibration transmitted to the hands and arms may contemplate the use of anti-vibration gloves. To make an informed decision about any type of personal protective equipment, it is necessary to have performance data that allow the degree of protection to be estimated. The information provided with an anti-vibration glove may not be easy to understand without some background knowledge of how gloves are tested and does not provide any clear route for estimating likely protection. Some of the factors that influence the potential efficacy of an anti-vibration glove include how risks from hand–arm vibration exposure are assessed, how the standard test for a glove is carried out, the frequency range and direction of the vibration for which protection is sought, how much hand contact force or pressure is applied and the physical limitations due to glove material and construction. This paper reviews some of the background issues that are useful for potential purchasers of anti-vibration gloves. Ultimately, anti-vibration gloves cannot be relied on to provide sufficient and consistent protection to the wearer and before their use is contemplated all other available means of vibration control ought first to be implemented. PMID:27582615

  4. Raynaud's phenomenon in vibration syndrome: the impact of cold feet on skin temperature and vasomotion of the hand after immersion in cold water.

    PubMed

    Falkenbach, A; Watanabe, I; Hartmann, B; Agishi, Y

    1997-12-01

    Patients with vibration syndrome, suffering from Raynaud's phenomenon, are sensitive to cold. Rewarming time, after local cooling, is delayed. The present study evaluated whether rewarming of the hand after cooling is influenced by the temperature of the feet. In five Japanese patients (former forest workers) with vibration syndrome, suffering from Raynaud's phenomenon, and in five healthy controls, temperature changes of the hand after cooling were registered under the two test situations (on different days) with the feet immersed in water of 35 degrees C or 20 degrees C, respectively. In both patients and controls (in both groups, in four of five cases) rewarming of the hand after cooling was faster when the feet were immersed in cold water, compared with when the feet were immersed in warm water. In this test situation, the systemic thermoregulative counterreaction appears to be more important for rewarming of the hand after cooling than a possible synchronous passive reaction accompanying warming of the feet. A deliberate training of the systemic counterreaction may prove beneficial for patients with Raynaud's phenomenon.

  5. INFRARED TRANSMITTING MATERIALS.

    DTIC Science & Technology

    The report deals with the infrared transmitting properties of fluorite structure oxides and the heavy metal covalent oxides of bismuth and lead. Transmission data for single crystal ThO2 are given. A theoretical analysis of the vibrational modes , selection rules and IR spectra of the powders are given for alpha-Bi2O3, PbO.6Bi2O3, tetragonal PbO, orthorhombic PbO, and Sr2PbO4. (Author)

  6. [Evaluation of vibration exposure long-term effects in people with diagnosed vibration syndrome].

    PubMed

    Wagrowska-Koski, Ewa; Lewańska, Magdalena; Rybacki, Marcin; Turbańska, Renata; Mikołajczyk, Anna; Łoś-Spychalska, Teresa

    2011-01-01

    Long-term exposure to hand-transmitted vibration can increase the occurrence of symptoms and signs of vascular neurological and musculoskeletal disorders of the upper extremities. The most common is the angioneurotic type of the vibration syndrome. Very little is known about possibility of withdrawal of symptoms after exposure cessation. The aim of the study was to evaluate the long-term effects of vibration exposure in people with diagnosed vibration syndrome. The particular aim of the study was to gain the information on possible withdrawal of symptoms in the peripheral vascular and nervous system after exposure cessation. The medical documentation of patients with vibration syndrome symptoms, examined in the years 1999-2004 in the Outpatient Clinic of the Nofer Institute of Occupational Medicine and in three Voivodeship Centers of Occupational Medicine has been analyzed. A group of 45 people who had been suffering from diagnosed angioneurotic vibration syndrome for at least 5 years was chosen. The mean age of the examined group at the time of occupational disease certification was 48.2 and the mean period of exposure to hand-transmitted vibration was nearly 20 years. The major group comprised persons with vibration syndrome diagnosed at an 'early symptoms' stage, an advanced stage of the disease was described in only 5 cases. From the time of occupational disease certification only 7 persons have been performing any job, and more than a half of the group has been granted disability pension. The results of the study show a bad prognosis of angioneurotic vibration syndrome despite cessation of the exposure to vibration. The total withdrawal of symptoms is possible only in people with vibration syndrome diagnosed at an 'early symptoms' stage, at young age and after short period of exposure.

  7. Cross sectional study of a workforce exposed to hand-arm vibration: with objective tests and the Stockholm workshop scales.

    PubMed

    McGeoch, K L; Gilmour, W H

    2000-01-01

    Medical surveillance of workforces exposed to vibration has been recommended with the Stockholm workshop scales. The aims of this study were (a) to evaluate how the results of the objective tests individually and jointly associated with the final Stockholm workshop staging, (b) how this staging related to the history of exposure to vibration, and (c) how different trades were affected by the hazards from vibrating tools. All workers exposed to vibration in a heavy engineering company were examined with a questionnaire and a battery of tests. An assessment of staging by the Stockholm workshop scales was made. Estimates of the daily exposure and lifetime dosage of vibration of the various trades were reached. The average years of tool use was 23.3 years (range 3-47 years) and the mean lifetime exposure was 11,022 (range 1012-46,125) hours. The individual neurological tests were all strongly associated with the Stockholm neurological staging but the cold provocation test was not associated with the Stockholm vascular staging. Neurological staging was significantly associated with age, years of tool use, and total hours of exposure to vibration, but not with trade or smoking. Vascular staging was significantly associated with age, years of tool use, total hours of exposure to vibration, and trade, but not with smoking. The mean neurological latent period was 19.7 (range 2-40) years and for the vascular component 19.1 (range 2-40) years. These means varied significantly by trade. The overall prevalence of neurological findings of 62% was greater than the overall prevalence of vascular findings, which was 33%. (1) The neurological objective tests were found to be of use in neurological staging. The cold provocation test was not associated with the vascular staging and therefore was of little value. (2) Years of tool use was the exposure variable most significantly associated with evidence of damage to neurological component while years of tool use and trade were the

  8. HTR1B gene variants associate with the susceptibility of Raynauds' phenomenon in workers exposed hand-arm vibration.

    PubMed

    Chen, Qingsong; Lang, Li; Xiao, Bin; Lin, Hansheng; Yang, Aichu; Li, Hongling; Tang, Shichuan; Huang, Hanlin

    2016-10-05

    To explore whether polymorphic variants of the HTR1B gene are associated with the susceptibility of Raynauds' Phenomenon (RP) coursed by vibration. 148 subjects exposed to vibration for more than 2 years were classified into either induced white finger (VWF) group (n = 72), or non-VWF group (n = 76). Vibration exposure levels were measured and assessed following ISO 5349-1:2001 protocol. All workers were genotyped by sequencing for the single nucleotide polymorphisms (SNPs) in the 5'-flanking and coding region of HTR1B. Genetic characteristics and linkage disequilibrium (LD) were analyzed with Haploview. Serum serotonin levels of each subject were detected using ELISA. The association between the susceptibility of vascular damage and genotype was analyzed via logistic regression. 7 known SNPs were obtained and their allele frequencies were inserted into the Hardy-Weinberg equilibrium. rs6297 variant genotype had an increased risk of VWF compared with wild genotype (OR = 2.14, 95% CI = 1.04- 4.58, P < 0.05). rs6298 mutant type (AG+GG) was found to have a significant interaction on vibration exposure LN(CEI), accounting for VWF occurrence. LN(5-HT) level is significantly different between the VWF group (x¯±s= 1.99±1.09 ng/mL) and the non-VWF group (x¯±s= 2.72±1.47 ng/mL). Serotonin levels may affect the progression of secondary RP. Polymorphic variants of the HTR1B gene are associated with the susceptibility of secondary RP in vibration-exposed occupational populations of Chinese Han people.

  9. Spatial resonance in a small artery excited by vibration input as a possible mechanism to cause hand-arm vascular disorders

    NASA Astrophysics Data System (ADS)

    Pattnaik, Shrikant; Banerjee, Rupak; Kim, Jay

    2012-04-01

    Hand-arm vibration syndrome (HAVS) is collectively a vasospastic and neurodegenerative occupational disease. One of the major symptoms of HAVS is vibration white finger (VWF) caused by exaggerated vasoconstriction of the arteries and skin arterioles. While VWF is a very painful and costly occupational illness, its pathology has not been well understood. In this study 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 resulting wave equation is the same as that of the basilar membrane in the cochlea of mammals. Therefore, the artery system shows a spatial resonance as in the basilar membrane, 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.

  10. Structural, electronic and vibrational properties of few-layer 2H-and 1T-TaSe2

    DOE PAGES

    Yan, Jia -An; Dela Cruz, Mack A.; Cook, Brandon G.; ...

    2015-11-16

    Two-dimensional metallic transition metal dichalcogenides (TMDs) are of interest for studying phenomena such as charge-density wave (CDW) and superconductivity. Few-layer tantalum diselenides (TaSe2) are typical metallic TMDs exhibiting rich CDW phase transitions. However, a description of the structural, electronic and vibrational properties for different crystal phases and stacking configurations, essential for interpretation of experiments, is lacking. We present first principles calculations of structural phase energetics, band dispersion near the Fermi level, phonon properties and vibrational modes at the Brillouin zone center for different layer numbers, crystal phases and stacking geometries. Evolution of the Fermi surfaces as well as the phononmore » dispersions as a function of layer number reveals dramatic dimensionality effects in this CDW material. Lastly, our results indicate strong electronic interlayer coupling, detail energetically possible stacking geometries, and provide a basis for interpretation of Raman spectra.« less

  11. Power tiller: vibration magnitudes and intervention development for vibration reduction.

    PubMed

    Chaturvedi, Varun; Kumar, Adarsh; Singh, J K

    2012-09-01

    The operators of power tiller are exposed to a high level of vibration originating from the dynamic interaction between the soil and the machine. The vibration from the power tiller is transmitted from the handle to hands, arms and shoulders. In the present study, experiments were conducted in three operational conditions i.e. transportation on farm roads, tilling with cultivator and rota-tilling with rota-vator. The highest vibration values were observed in x-direction in all the experiments. The maximum vibration rms values for x-direction were 5.96, 6.81 and 8.00 ms(-2) in tilling with cultivator, transportation and rota-tilling respectively. Three materials were used for intervention development to reduce vibration magnitude. The maximum reduction of 25.30, 31.21 and 30.45% in transportation; 23.50, 30.64 and 20.86% in tilling with cultivator and 24.03, 29.18 and 25.52% in rota-tilling were achieved with polyurethane (PU), rubber and combination of PU and rubber intervention. It was found that the maximum vibration reductions were achieved with the rubber in all three operational conditions. The average exposure time for occurrence of white finger syndrome increased by 28-50% with incorporation of intervention in different operations. Physiological and postural parameters also improved with incorporation of interventions. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  12. Biodynamic response of human fingers in a power grip subjected to a random vibration.

    PubMed

    Dong, R G; Welcome, D E; McDowell, T W; Wu, J Z

    2004-08-01

    Knowledge of the biodynamic response (BR) of the human hand-arm system is an important part of the foundation for the measurement and assessment of hand-transmitted vibration exposure. This study investigated the BR of human fingers in a power grip subjected to a random vibration. Ten male subjects were used in the experiment. Each subject applied three coupling actions to a simulated tool handle at three different finger grip force levels. The BR is practically independent of the hand coupling actions for frequencies at or above 100 Hz. Above 50 Hz, the BR is correlated to finger and hand sizes. Increasing the finger coupling force significantly increases the BR. Therefore, hand forces should be measured and used when assessing hand-transmitted vibration exposure. The results also show that under a constant-velocity vibration, the finger vibration power absorption at frequencies above 200 Hz is approximately twice that at frequencies below 100 Hz. This suggests that the frequency weighting specified in the current ISO 5349-1 (2001) may underestimate the high frequency effect on vibration-induced finger disorders.

  13. Suspected vibration magnitude on the body of chain saw users among National Forest workers in Kyusyu, from 1956 to 1984.

    PubMed

    Sakurai, T

    1990-01-01

    Chain saws were first used in Kyusyu in 1956 for cutting down trees and sawing timber in the national forests. In 1961, some workers complained of symptoms due to the vibrations, but countermeasures were not taken until later. The working system and payment system in those times were different from the systems, today. The magnitudes of the chain saw vibrations were very large and the chain saws were operated for many hours, each day. Workers with VWF (vibration induced white finger) had to continue to operate the chain saws without restriction. Vibration disease is related primarily to the vibration of the tools, but also to the transmission of the vibration to the workers. From the official data on chain saws used in national forests, vibration transmission to the body was determined for workers from 1956 to 1984 by comparing the vibration magnitude on the body during work with modern chain saws and during vibration loading tests with an electrodynamic shaker in the laboratory. The vibrations transmitted to the body in some rule in the observation. If the working posture of chain saw operator was the same as today, the vibration transmission was determined from the tool vibration, tool weight, joint fixation and orientation of the hands and the hands and the arms to the handle (joint elasticity). Older chain saws had 20 to 30 times larger vibration magnitudes than modern chain saws, and were also 2 to 3 times heavier. The vibrations transmitted to the foreheads of earlier workers were approximately the same magnitude as the vibrations at the back of the hands of present workers. Also the daily and annual hours of chain saw use were very long, and there were not sufficient measures to protect from the cold. The vibration in the former days led to more symptoms and lesions than in present times.

  14. Influence of vibration exposure on tactile and thermal perception thresholds.

    PubMed

    Burström, Lage; Hagberg, Mats; Lundström, Ronnie; Nilsson, Tohr

    2009-05-01

    To establish if intermittent exposure to hand-transmitted vibration had the same effect as continuous exposure on the temporary response of finger tactile and thermal perception thresholds. Two laboratory experiments were conducted. In each, 10 healthy subjects, five males and five females, participated. The subjects' fingers were exposed to vibration under four conditions with a combination of different periods of exposure and rest periods. The vibration frequency was 125 Hz and the frequency-weighted acceleration was 5 m/s(2). A measure of the tactile or thermal perception was conducted before the different exposures to vibration. Immediately after the vibration exposure, the acute effect was measured continuously for the first 75 s. This was followed by regular measures for a maximum of 30 min. The results showed that combinations of vibration with different periods of exposure and rest periods significantly influenced vibrotactile perception, but not thermal perception. These findings suggest that intermittent exposure to hand-transmitted vibration might be more beneficial for the response of the finger vibrotactile sensation than continuous exposure. This finding is inconsistent with the evaluation methods in ISO 5349-1 for vibrotactile sensation, but accurate for thermal perception.

  15. The Effect of a Mechanical Arm System on Portable Grinder Vibration Emissions.

    PubMed

    McDowell, Thomas W; Welcome, Daniel E; Warren, Christopher; Xu, Xueyan S; Dong, Ren G

    2016-04-01

    Mechanical arm systems are commonly used to support powered hand tools to alleviate ergonomic stressors related to the development of workplace musculoskeletal disorders. However, the use of these systems can increase exposure times to other potentially harmful agents such as hand-transmitted vibration. To examine how these tool support systems affect tool vibration, the primary objectives of this study were to characterize the vibration emissions of typical portable pneumatic grinders used for surface grinding with and without a mechanical arm support system at a workplace and to estimate the potential risk of the increased vibration exposure time afforded by the use of these mechanical arm systems. This study also developed a laboratory-based simulated grinding task based on the ISO 28927-1 (2009) standard for assessing grinder vibrations; the simulated grinding vibrations were compared with those measured during actual workplace grinder operations. The results of this study demonstrate that use of the mechanical arm may provide a health benefit by reducing the forces required to lift and maneuver the tools and by decreasing hand-transmitted vibration exposure. However, the arm does not substantially change the basic characteristics of grinder vibration spectra. The mechanical arm reduced the average frequency-weighted acceleration by about 24% in the workplace and by about 7% in the laboratory. Because use of the mechanical arm system can increase daily time-on-task by 50% or more, the use of such systems may actually increase daily time-weighted hand-transmitted vibration exposures in some cases. The laboratory acceleration measurements were substantially lower than the workplace measurements, and the laboratory tool rankings based on acceleration were considerably different than those from the workplace. Thus, it is doubtful that ISO 28927-1 is useful for estimating workplace grinder vibration exposures or for predicting workplace grinder acceleration rank

  16. The Effect of a Mechanical Arm System on Portable Grinder Vibration Emissions

    PubMed Central

    McDowell, Thomas W.; Welcome, Daniel E.; Warren, Christopher; Xu, Xueyan S.; Dong, Ren G.

    2016-01-01

    Mechanical arm systems are commonly used to support powered hand tools to alleviate ergonomic stressors related to the development of workplace musculoskeletal disorders. However, the use of these systems can increase exposure times to other potentially harmful agents such as hand-transmitted vibration. To examine how these tool support systems affect tool vibration, the primary objectives of this study were to characterize the vibration emissions of typical portable pneumatic grinders used for surface grinding with and without a mechanical arm support system at a workplace and to estimate the potential risk of the increased vibration exposure time afforded by the use of these mechanical arm systems. This study also developed a laboratory-based simulated grinding task based on the ISO 28927-1 (2009) standard for assessing grinder vibrations; the simulated grinding vibrations were compared with those measured during actual workplace grinder operations. The results of this study demonstrate that use of the mechanical arm may provide a health benefit by reducing the forces required to lift and maneuver the tools and by decreasing hand-transmitted vibration exposure. However, the arm does not substantially change the basic characteristics of grinder vibration spectra. The mechanical arm reduced the average frequency-weighted acceleration by about 24% in the workplace and by about 7% in the laboratory. Because use of the mechanical arm system can increase daily time-on-task by 50% or more, the use of such systems may actually increase daily time-weighted hand-transmitted vibration exposures in some cases. The laboratory acceleration measurements were substantially lower than the workplace measurements, and the laboratory tool rankings based on acceleration were considerably different than those from the workplace. Thus, it is doubtful that ISO 28927-1 is useful for estimating workplace grinder vibration exposures or for predicting workplace grinder acceleration rank

  17. Vibration training for upper body: transmission of platform vibrations through cables.

    PubMed

    Tankisheva, Ekaterina; Boonen, Steven; Delecluse, Christophe; Druyts, Hans Lj; Verschueren, Sabine M P

    2014-04-01

    The aim of the present study was to evaluate the vibration transmission from a vibration platform through Vectran cables to the upper body and its relationship to induced muscular activation. Fifteen clinically healthy participants performed 3 different arm exercises-biceps curl, triceps curl, and lateral raise. Vibration transmission to the upper body was assessed over a wide range of accelerations (from 1.90 to 5.98 g) and frequencies (from 25 to 40 Hz). To assess the vibration transmission, 7 triaxial accelerometers were attached from the hand up to the head, and the root-mean-square of acceleration signal of each site-specific body point was calculated. Muscular activity of biceps brachii, triceps brachii, deltoid, and upper trapezius was recorded. The results showed a significant attenuation of the platform accelerations transmitted through the Vectran cables to the upper body. Handle vibration ranged between 27 and 44% of the acceleration delivered by the platform depending on platform vibration parameters (acceleration/frequency). Vibration increased the muscle activity of biceps brachii, triceps brachii, deltoid, and upper trapezius muscles significantly only during biceps curl exercises. No frequency or acceleration effect was found on the size of the muscle response. The results of the present study suggest that a cable-pulley resistance system on a vibration platform channels the vibration safely from the platform to the arms and induces additional muscle activation in some arm muscles when biceps curl exercises are performed.

  18. A systematic review of the etiopathogenesis of Kienböck's disease and a critical appraisal of its recognition as an occupational disease related to hand-arm vibration

    PubMed Central

    2012-01-01

    Background We systematically reviewed etiological factors of Kienböck’s disease (osteonecrosis of the lunate) discussed in the literature in order to examine the justification for including Kienböck’s disease (KD) in the European Listing of Occupational Diseases. Methods We searched the Ovid/Medline and the Cochrane Library for articles discussing the etiology of osteonecrosis of the lunate published since the first description of KD in 1910 and up until July 2012 in English, French or German. Literature was classified by the level of evidence presented, the etiopathological hypothesis discussed, and the author's conclusion about the role of the etiopathological hypothesis. The causal relationship between KD and hand-arm vibration was elucidated by the Bradford Hill criteria. Results A total of 220 references was found. Of the included 152 articles, 140 (92%) reached the evidence level IV (case series). The four most frequently discussed factors were negative ulnar variance (n=72; 47%), primary arterial ischemia of the lunate (n=63; 41%), trauma (n=63; 41%) and hand-arm vibration (n=53; 35%). The quality of the cohort studies on hand-arm vibration did not permit a meta-analysis to evaluate the strength of an association to KD. Evidence for the lack of consistency, plausibility and coherence of the 4 most frequently discussed etiopathologies was found. No evidence was found to support any of the nine Bradford Hill criteria for a causal relationship between KD and hand-arm vibration. Conclusions A systematic review of 220 articles on the etiopathology of KD and the application of the Bradford Hill criteria does not provide sufficient scientific evidence to confirm or refute a causal relationship between KD and hand-arm vibration. This currently suggests that, KD does not comply with the criteria of the International Labour Organization determining occupational diseases. However, research with a higher level of evidence is required to further determine if hand

  19. Hand-arm vibration syndrome (HAVS) and musculoskeletal symptoms in the neck and the upper limbs in professional drivers of terrain vehicles--a cross sectional study.

    PubMed

    Aström, Charlotte; Rehn, Börje; Lundström, Ronnie; Nilsson, Tohr; Burström, Lage; Sundelin, Gunnevi

    2006-11-01

    This study compares the prevalence of symptoms of Hand-arm vibration syndrome (HAVS) and musculoskeletal symptoms in the neck and the upper limbs, between professional drivers of terrain vehicles and a referent group. 769 male professional drivers of forest machines, snowmobiles, snowgroomers and reindeer herders and 296 randomly selected male referents completed a questionnaire about symptoms of HAVS and musculoskeletal symptoms in the neck and the upper limbs. They also gave information about their lifetime exposure duration driving terrain vehicles and their nicotine use. Prevalence odds ratios (POR) were determined and adjusted for age and nicotine use. Results show that there is a relation between exposure to driving terrain vehicles and some of the symptoms of HAVS (POR: 1.2-6.1). Increased odds of musculoskeletal symptoms in neck, shoulders and wrists were also found (POR 1.2-6.4), and it seemed to be related to the cumulative exposure time.

  20. Rock drills used in South African mines: a comparative study of noise and vibration levels.

    PubMed

    Phillips, J I; Heyns, P S; Nelson, G

    2007-04-01

    To compare the noise and vibration levels associated with three hand-held rock drills (pneumatic, hydraulic and electric) currently used in South African mines, and a prototype acoustically shielded self-propelled rock drill. Equivalent A-weighted sound pressure levels were recorded on a geometrical grid, using Rion NL-11 and NL-14 sound level meters. Vibration measurements were conducted on the pneumatic, hydraulic and electric drills in accordance with the ISO5349-1 (2001) international standard on human exposure to hand-transmitted vibration, using a Brupsilonel and Kjaer UA0894 hand adaptor. PCB Piezo accelerometers were used to measure vibration in three orthogonal directions. No vibration measurements were conducted on the self-propelled drill. All four drills emitted noise exceeding 85 dB(A). The pneumatic drill reached levels of up to 114 dB(A), while the shielded self-propelled drill almost complied with the 85 dB(A) 8 h exposure limit. Vibration levels of up to 31 m s(-2) were recorded. These levels greatly exceed recommended and legislated levels. Significant engineering advances will need to be made in the manufacture of rock drills to impact on noise induced hearing loss and hand arm vibration syndrome. Isolating the operator from the drill, as for the self-propelled drill, addresses the problems of both vibration and noise exposure, and is a possible direction for future development.

  1. Laboratory and workplace assessments of rivet bucking bar vibration emissions.

    PubMed

    McDowell, Thomas W; Warren, Christopher; Xu, Xueyan S; Welcome, Daniel E; Dong, Ren G

    2015-04-01

    Sheet metal workers operating rivet bucking bars are at risk of developing hand and wrist musculoskeletal disorders associated with exposures to hand-transmitted vibrations and forceful exertions required to operate these hand tools. New bucking bar technologies have been introduced in efforts to reduce workplace vibration exposures to these workers. However, the efficacy of these new bucking bar designs has not been well documented. While there are standardized laboratory-based methodologies for assessing the vibration emissions of many types of powered hand tools, no such standard exists for rivet bucking bars. Therefore, this study included the development of a laboratory-based method for assessing bucking bar vibrations which utilizes a simulated riveting task. With this method, this study evaluated three traditional steel bucking bars, three similarly shaped tungsten alloy bars, and three bars featuring spring-dampeners. For comparison the bucking bar vibrations were also assessed during three typical riveting tasks at a large aircraft maintenance facility. The bucking bars were rank-ordered in terms of unweighted and frequency-weighted acceleration measured at the hand-tool interface. The results suggest that the developed laboratory method is a reasonable technique for ranking bucking bar vibration emissions; the lab-based riveting simulations produced similar rankings to the workplace rankings. However, the laboratory-based acceleration averages were considerably lower than the workplace measurements. These observations suggest that the laboratory test results are acceptable for comparing and screening bucking bars, but the laboratory measurements should not be directly used for assessing the risk of workplace bucking bar vibration exposures. The newer bucking bar technologies exhibited significantly reduced vibrations compared to the traditional steel bars. The results of this study, together with other information such as rivet quality, productivity, tool

  2. Laboratory and Workplace Assessments of Rivet Bucking Bar Vibration Emissions

    PubMed Central

    McDowell, Thomas W.; Warren, Christopher; Xu, Xueyan S.; Welcome, Daniel E.; Dong, Ren G.

    2016-01-01

    Sheet metal workers operating rivet bucking bars are at risk of developing hand and wrist musculoskeletal disorders associated with exposures to hand-transmitted vibrations and forceful exertions required to operate these hand tools. New bucking bar technologies have been introduced in efforts to reduce workplace vibration exposures to these workers. However, the efficacy of these new bucking bar designs has not been well documented. While there are standardized laboratory-based methodologies for assessing the vibration emissions of many types of powered hand tools, no such standard exists for rivet bucking bars. Therefore, this study included the development of a laboratory-based method for assessing bucking bar vibrations which utilizes a simulated riveting task. With this method, this study evaluated three traditional steel bucking bars, three similarly shaped tungsten alloy bars, and three bars featuring spring-dampeners. For comparison the bucking bar vibrations were also assessed during three typical riveting tasks at a large aircraft maintenance facility. The bucking bars were rank-ordered in terms of unweighted and frequency-weighted acceleration measured at the hand-tool interface. The results suggest that the developed laboratory method is a reasonable technique for ranking bucking bar vibration emissions; the lab-based riveting simulations produced similar rankings to the workplace rankings. However, the laboratory-based acceleration averages were considerably lower than the workplace measurements. These observations suggest that the laboratory test results are acceptable for comparing and screening bucking bars, but the laboratory measurements should not be directly used for assessing the risk of workplace bucking bar vibration exposures. The newer bucking bar technologies exhibited significantly reduced vibrations compared to the traditional steel bars. The results of this study, together with other information such as rivet quality, productivity, tool

  3. Vibrating fuel grapple. [LMFBR

    DOEpatents

    Chertock, A.J.; Fox, J.N.; Weissinger, R.B.

    A reactor refueling method is described which utilizes a vibrating fuel grapple for removing spent fuel assemblies from a reactor core. It incorporates a pneumatic vibrator in the grapple head which allows additional withdrawal capability without exceeding the allowable axial force limit. The only moving part in the vibrator is a steel ball, pneumatically driven by a gas, such as argon, around a track, with centrifugal force created by the ball being transmitted through the grapple to the assembly handling socket.

  4. Vibrating fuel grapple

    DOEpatents

    Chertock, deceased, Alan J.; Fox, Jack N.; Weissinger, Robert B.

    1982-01-01

    A reactor refueling method utilizing a vibrating fuel grapple for removing spent fuel assemblies from a reactor core which incorporates a pneumatic vibrator in the grapple head, enabling additional withdrawal capability without exceeding the allowable axial force limit. The only moving part in the vibrator is a steel ball, pneumatically driven by a gas, such as argon, around a track, with centrifugal force created by the ball being transmitted through the grapple to the assembly handling socket.

  5. Effect of coating over the handle of a drill machine on vibration transmissibility.

    PubMed

    Singh, Jagvir; Khan, Abid Ali

    2014-03-01

    This study was to see the effect of different coatings on the handle of hand-held drilling machines. Out of five different handles chosen for this study, including one handle uncoated. Root mean square (rms) values of the vibration levels (acceleration) were recorded at the surface of handle and wrist of the operators. Results showed that maximum vibrations were reduced by coating of handle coated with rubber sheet and Rexene (H4) followed by handle coated with cotton sandwiched between jeans cloth (H5). Equivalent vibrations transmitted through coating of handles coated with sponge and velvet (H2) and jute and cotton (H3) were of almost same magnitude and these two coated handles were able to reduce least vibration transmitted. Transmissibility of vibrations along dominant (Z) direction was analyzed using ANOVA. Results showed that coating on handles significantly affected vibration transmitted in Z direction. Vibration transmissibility ratios were found to be 0.354, 0.571, 0.408, 0.4326, and 0.3555 for handles H1, H2, H3, H4 and H5 respectively.

  6. Vibration-induced multifocal neuropathy in forestry workers: electrophysiological findings in relation to vibration exposure and finger circulation.

    PubMed

    Bovenzi, M; Giannini, F; Rossi, S

    2000-11-01

    To investigate neural conduction in the upper limbs of symptomatic forestry workers with and without exposure to hand-transmitted vibration. A further aim was to assess the possible relationships between vibration exposure, nerve conduction and finger circulation in the forestry workers who used chain saws. A detailed neurophysiological investigation was performed on the upper extremities of 20 chain saw workers, 20 forestry operators with heavy manual work but without vibration exposure, and 20 healthy male controls. All subjects were screened to exclude polyneuropathy. Measurements of sensory and motor nerve conduction (velocity and amplitude) were obtained bilaterally from the median, ulnar and radial nerves. To assess peripheral vascular function, the forestry workers underwent a cold test with plethysmographic measurement of finger systolic blood pressure (FSBP). In the chain saw operators, vibration exposure was evaluated according to the International Standard ISO 5349. Indices of daily vibration exposure and lifetime cumulative vibration dose were estimated for each chain saw operator. Sensory nerve conduction in several segments of the median and radial nerves was significantly reduced in the chain saw operators compared with that in the workers doing heavy manual work and the controls. The neurophysiological pattern more frequently observed in the chain saw operators was a multifocal nerve conduction impairment to several neural segments with predominant involvement of sensory rather than motor fibres. Sensory nerve conduction velocities in the hands of the chain saw operators were inversely related to both daily and lifetime cumulative vibration exposures. In the vibration-exposed forestry workers, neither were sensori-motor complaints associated with vascular symptoms (finger whiteness) nor were electrophysiological data related to cold-induced changes in FSBP. Exposure to hand-transmitted vibration, in addition to ergonomic stress factors, can

  7. Vibration Analysis and the Accelerometer

    ERIC Educational Resources Information Center

    Hammer, Paul

    2011-01-01

    Have you ever put your hand on an electric motor or motor-driven electric appliance and felt it vibrate? Ever wonder why it vibrates? What is there about the operation of the motor, or the object to which it is attached, that causes the vibrations? Is there anything "regular" about the vibrations, or are they the result of random causes? In this…

  8. Vibration Analysis and the Accelerometer

    ERIC Educational Resources Information Center

    Hammer, Paul

    2011-01-01

    Have you ever put your hand on an electric motor or motor-driven electric appliance and felt it vibrate? Ever wonder why it vibrates? What is there about the operation of the motor, or the object to which it is attached, that causes the vibrations? Is there anything "regular" about the vibrations, or are they the result of random causes? In this…

  9. Hand-Strength Meter

    NASA Technical Reports Server (NTRS)

    Tcheng, Ping; Elliot, Joe

    1987-01-01

    Special grip-strength meter designed for accurate, reproducible measurement of hand rehabilitation. Four strain gauges connected in Wheatstone bridge to measure deflection caused by gripping hand. Compressive force exerted by hand transmitted to measuring beams. Beams therefore deflected or strained, and mechanical strain sensed by strain gauges and converted into electrical signal. After amplification and conditioning, signal displayed on LED as measure of gripping strength of hand.

  10. Characterization of Frequency-Dependent Responses of the Vascular System to Repetitive Vibration

    PubMed Central

    Krajnak, Kristine; Miller, G. Roger; Waugh, Stacey; Johnson, Claud; Kashon, Michael L.

    2015-01-01

    Objective Occupational exposure to hand-transmitted vibration can result in damage to nerves and sensory loss. The goal of this study was to assess the frequency-dependent effects of repeated bouts of vibration on sensory nerve function and associated changes in nerves. Methods The tails of rats were exposed to vibration at 62.5, 125, or 250 Hz (constant acceleration of 49m/s2) for 10 days. The effects on sensory nerve function, nerve morphology, and transcript expression in ventral tail nerves were measured. Results Vibration at all frequencies had effects on nerve function and physiology. However, the effects tended to be more prominent with exposure at 250 Hz. Conclusion Exposure to vibration has detrimental effects on sensory nerve function and physiology. However, many of these changes are more prominent at 250-Hz exposure than at lower frequencies. PMID:22785326

  11. Response of finger circulation to energy equivalent combinations of magnitude and duration of vibration

    PubMed Central

    Bovenzi, M; Lindsell, C; Griffin, M

    2001-01-01

    OBJECTIVES—To investigate the acute response of finger circulation to vibration with different combinations of magnitude and duration but with the same "energy equivalent" acceleration magnitude according to current standards for hand transmitted vibration.
METHODS—Finger skin temperature (FST) and finger blood flow (FBF) were measured in the middle fingers of both hands of 10 healthy men who had not used hand held vibrating tools regularly. With a static load of 10 N, the right hand was exposed to 125 Hz vibration with the following unweighted root mean square (rms) acceleration magnitudes and durations of exposure: 44 m/s2 for 30 minutes; 62 m/s2 for 15 minutes; 88 m/s2 for 7.5 minutes; 125 m/s2 for 3.75 minutes; and 176 m/s2 for 1.88 minutes. These vibration exposures produce the same 8 hour energy equivalent frequency weighted acceleration magnitude (~1.4 m/s2 rms) according to international standard ISO 5349 (1986). Finger circulation was measured in both the right (vibrated) and the left (non-vibrated) middle fingers before application of the vibration, and at fixed intervals during exposure to vibration and during a 45 minute recovery period.
RESULTS—The FST did not change during exposure to vibration, whereas vibration with any combination of acceleration magnitude and duration produced significant percentage reductions in the FBF of the vibrated finger compared with the FBF before exposure (from −40.1% (95% confidence interval (95% CI) −24.3% to −57.2%) to −61.4% (95% CI −45.0% to −77.8%). The reduction in FBF during vibration was stronger in the vibrated finger than in the non-vibrated finger. Across the five experimental conditions, the various vibration stimuli caused a similar degree of vasoconstriction in the vibrated finger during exposure to vibration. There was a progressive decrease in the FBF of both fingers after the end of exposure to vibration with acceleration magnitudes of 44 m/s2 for 30 minutes and 62

  12. Diagnostic performance of cold provocation test with hands immersion in water at 10°C for 5 min evaluated in vibration-induced white finger patients and matched controls.

    PubMed

    Mahbub, M H; Ishitake, Tatsuya; Kurozawa, Youichi; Toibana, Norikuni; Ide, Fuyoumi; Ohnari, Hiroto; Tanigawa, Kazuko; Takahashi, Yukio; Harada, Noriaki

    2011-10-01

    This study aimed to explore the diagnostic ability of the cold provocation test with hands immersion in water at 10°C for 5 min in diagnosing vibration-induced white finger (VWF). Finger skin temperature (FST) was measured in 20 VWF patients and 20 matched healthy controls, at palmar side of the distal phalanges of fingers from both hands before, during, and after hands immersion in water at 10°C (for 5 min with waterproof coverings put on both hands). Data from 4 fingers (except thumb) were evaluated at five time points: just before immersion, last minute during immersion, and at 5th, 10th, and 15th min during the post-immersion or recovery period. A positive group difference between patients and controls was revealed during the recovery period. During recovery at 95 and 70% specificity, the sensitivity ranged from 20 to 30% and 50 to 70% for evaluation with average FST for 4 fingers and 15-35% and 60-65% for evaluation with minimum FST among 4 fingers, respectively. Overall, evaluation of absolute FST at 15th min of recovery offered better diagnostic ability. The cold provocation test with hands immersion in water at 10°C for 5 min could discriminate VWF patients from healthy controls; however, this test has a limited diagnostic value in diagnosing patients with VWF.

  13. Description/demonstration of BIODYN-80. A software package for evaluating the transmissibility between vehicle vibration and motions of hands (in controls), limbs, head and eyes

    NASA Technical Reports Server (NTRS)

    Riedel, S. A.; Jex, H. R.; Magdaleno, R. E.

    1982-01-01

    A user-oriented program for exercising the 1980 verson of the biodynamic model BIODYN-80 is described. The user inputs (modifies) some 80-100 variables describing the assumed posture, interface characteristics (e.g., stick "feel" properties), and vestibular characteristics. The computer calculates the transfer functions between vibration input and various selected outputs of interest to the user. Another option is to output the operator's torso-limb-neuromuscular loop transmissibilities as seen at the stick, as required for the PIVIB computer program for computing tracking performance effects of vibration. Applications to some current problems are demonstrated.

  14. Study of vibrations produced by a vibrating beam used for vibrating concretes. [and their transmission to human operator

    NASA Technical Reports Server (NTRS)

    Silas, C.; Brindeu, L.; Grosanu, I.; Cioara, T.

    1974-01-01

    For compacting concretes in building, vibrating beams are used. The vibrations are generated by inertial vibrators, and the beam is normally displaced by the operator by means of a handle that is elastically fastened to the beam by means of rubber pads. Considered are vibrations transmitted to the operator, taking into account the beam's shock vibration motions. The steady state motion of a dynamic beam pattern is studied, and results of experimental tests with existing equipment are presented.

  15. Development of vibration isolation platform for low amplitude vibration

    NASA Astrophysics Data System (ADS)

    Lee, Dae-Oen; Park, Geeyong; Han, Jae-Hung

    2014-03-01

    The performance of high precision payloads on board a satellite is extremely sensitive to vibration. Although vibration environment of a satellite on orbit is very gentle compared to the launch environment, even a low amplitude vibration disturbances generated by reaction wheel assembly, cryocoolers, etc may cause serious problems in performing tasks such as capturing high resolution images. The most commonly taken approach to protect sensitive payloads from performance degrading vibration is application of vibration isolator. In this paper, development of vibration isolation platform for low amplitude vibration is discussed. Firstly, single axis vibration isolator is developed by adapting three parameter model using bellows and viscous fluid. The isolation performance of the developed single axis isolator is evaluated by measuring force transmissibility. The measured transmissibility shows that both the low Q-factor (about 2) and the high roll-off rate (about -40 dB/dec) are achieved with the developed isolator. Then, six single axis isolators are combined to form Stewart platform in cubic configuration to provide multi-axis vibration isolation. The isolation performance of the developed multi-axis isolator is evaluated using a simple prototype reaction wheel model in which wheel imbalance is the major source of vibration. The transmitted force without vibration isolator is measured and compared with the transmitted force with vibration isolator. More than 20 dB reduction of the X and Y direction (radial direction of flywheel) disturbance is observed for rotating wheel speed of 100 Hz and higher.

  16. Hand to hand.

    PubMed

    Bedell, Susanna E; Graboys, Thomas B

    2002-08-01

    Examination of the hands has the potential to transform the encounter between physician and patient. Taking the hands conveys a sense of warmth and connectedness and is a means to communicate the physician's mindfulness. The hands can focus the examination on the individual patient as a complete human being, and not merely a disease or a collection of symptoms. The hands provide readily accessible information that may not be available through other evaluations, and they offer clues to a patient's physical and mental health. Commonplace observations, such as those revealed in the hands, can unravel medical mysteries and provide profound clinical insights.

  17. Structural, electronic and vibrational properties of few-layer 2H-and 1T-TaSe2

    SciTech Connect

    Yan, Jia -An; Dela Cruz, Mack A.; Cook, Brandon G.; Varga, Kalman

    2015-11-16

    Two-dimensional metallic transition metal dichalcogenides (TMDs) are of interest for studying phenomena such as charge-density wave (CDW) and superconductivity. Few-layer tantalum diselenides (TaSe2) are typical metallic TMDs exhibiting rich CDW phase transitions. However, a description of the structural, electronic and vibrational properties for different crystal phases and stacking configurations, essential for interpretation of experiments, is lacking. We present first principles calculations of structural phase energetics, band dispersion near the Fermi level, phonon properties and vibrational modes at the Brillouin zone center for different layer numbers, crystal phases and stacking geometries. Evolution of the Fermi surfaces as well as the phonon dispersions as a function of layer number reveals dramatic dimensionality effects in this CDW material. Lastly, our results indicate strong electronic interlayer coupling, detail energetically possible stacking geometries, and provide a basis for interpretation of Raman spectra.

  18. Sexually transmitted diphtheria.

    PubMed

    Berger, Anja; Lensing, Carmen; Konrad, Regina; Huber, Ingrid; Hogardt, Michael; Sing, Andreas

    2013-03-01

    Diphtheria is caused by diphtheria toxin-producing Corynebacterium species. While classical respiratory diphtheria is transmitted by droplets, cutaneous diphtheria often results from minor trauma. This report concerns the first case of sexually transmitted diphtheria in a patient with non-gonococcal urethritis after orogenital contact.

  19. Multiple direction vibration fixture

    DOEpatents

    Cericola, Fred; Doggett, James W.; Ernest, Terry L.; Priddy, Tommy G.

    1991-01-01

    An apparatus for simulating a rocket launch environment on a test item undergoing centrifuge testing by subjecting the item simultaneously or separately to vibration along an axis of centripetal force and along an axis perpendicular to the centripetal force axis. The apparatus includes a shaker motor supported by centrifuge arms and a right angle fixture pivotally connected to one of the shaker motor mounts. When the shaker motor vibrates along the centripetal force axis, the vibrations are imparted to a first side of the right angle fixture. The vibrations are transmitted 90 degrees around the pivot and are directed to a second side of the right angle fixture which imparts vibrations perpendicular to the centripetal force axis. The test item is in contact with a third side of the right angle fixture and receives both centripetal-force-axis vibrations and perpendicular axis vibrations simultaneously. A test item can be attached to the third side near the flexible coupling or near the air bag to obtain vibrations along the centripetal force axis or transverse to the centripetal force axis.

  20. Multiple direction vibration fixture

    SciTech Connect

    Cericola, F.; Doggett, J.W.; Ernest, T.L.; Priddy, T.G.

    1990-03-21

    An apparatus for simulating a rocket launch environment on a test item undergoing centrifuge testing by subjecting the item simultaneously or separately to vibration along an axis of centripetal force and along an axis perpendicular to the centripetal force axis. The apparatus includes a shaker motor supported by centrifuge arms and a right angle fixture pivotally connected to one of the shaker motor mounts. When the shaker motor vibrates along the centripetal force axis, the vibrations are imparted to a first side of the right angle fixture. The vibrations are transmitted 90 degrees around the pivot and are directed to a second side of the right angle fixture which imparts vibrations perpendicular to the centripetal force axis. The test item is in contact with a third side of the right angle fixture and receives both centripetal-force-axis vibrations and perpendicular axis vibrations simultaneously. A test item can be attached to the third side near the flexible coupling or near the air bag to obtain vibrations along the centripetal force axis or transverse to the centripetal force axis. 1 fig.

  1. Multiple direction vibration fixture

    SciTech Connect

    Cericola, F.; Doggett, J.W.; Ernest, T.L.

    1991-08-27

    An apparatus is discussed for simulating a rocket launch environment on a test item undergoing centrifuge testing by subjecting the item simultaneously or separately to vibration along an axis of centripetal force and along an axis perpendicular to the centripetal force axis. The apparatus includes a shaker motor supported by centrifuge arms and a right angle fixture pivotally connected to one of the shaker motor mounts. When the shaker motor vibrates along the centripetal force axis, the vibrations are imparted to a first side of the right angle fixture. The vibrations are transmitted 90 {degrees} around the pivot and are directed to a second side of the right angle fixture which imparts vibrations perpendicular to the centripetal force axis. The test item is in contact with a third side of the right angle fixture and receives both centripetal-force-axis vibrations and perpendicular axis vibrations simultaneously. A test item can be attached to the third side near the flexible coupling or near the air bag to obtain vibrations along the centripetal force axis or transverse to the centripetal force axis.

  2. Vibration syndrome

    PubMed Central

    Stewart, Alice M.; Goda, D. F

    1970-01-01

    Stewart, Alice M., and Goda, D. F. (1970).Brit. J. industr. Med.,27, 19-27. Vibration syndrome. Raynaud's phenomenon, or the finger blanching of men who work with vibrating tools, is undoubtedly due to vasospasm. Nevertheless the abnormal element in the situation is not a series of traumatized nerve endings but a deposition of callus under the palmar surfaces of fingers and thumbs. This deposition is a late consequence of the most distinctive, but not necessarily the most painful, of the numerous effects incurred as a result of the tool speed being completely out of the control of the operator and of the tool/component rebound being only partially under his control. The replacement of soft finger pads by rigid callus is also the only consequence of hard manual work to show how necessary it is for a structure like a finger–which is largely composed of bones, joints, tendons, and skin–to have a reservoir, the equivalent of a blood-filled sponge, between every joint to accommodate any sudden reduction in blood volume, or indeed any sudden increase in the volume of blood held in the arteries and veins relative to the amount held in the capillaries. It is still a moot point whether users of vibrating tools have more arm complaints of a serious nature than other manual workers. They do, however, have a multiplicity of aches and pains, ascribable to various causes including tool speed and tool/component rebound, which are in toto very sensitive to such things as blunt impacts, hard components, heavy tools, awkward jobs, and inept handling of tools, whether the ineptness be due to inexperience or to advancing age. Users of vibrating tools have more pain in the hands and wrists than in the elbows and shoulders, but the pain tends to persist longer in the latter sites than in the former sites. PMID:5418915

  3. Vibration induced white-feet: Overview and field study of vibration exposure and reported symptoms in workers

    PubMed Central

    Eger, Tammy; Thompson, Aaron; Leduc, Mallorie; Krajnak, Kristine; Goggins, Katie; Godwin, Alison; House, Ron

    2015-01-01

    BACKGROUND Workers who stand on platforms or equipment that vibrate are exposed to foot-transmitted vibration (FTV). Exposure to FTV can lead to vibration white feet/toes resulting in blanching of the toes, and tingling and numbness in the feet and toes. OBJECTIVES The objectives are 1) to review the current state of knowledge of the health risks associated with foot-transmitted vibration (FTV), and 2) to identify the characteristics of FTV and discuss the associated risk of vibration-induced injury. PARTICIPANTS Workers who operated locomotives (n = 3), bolting platforms (n = 10), jumbo drills (n = 7), raise drilling platforms (n = 4), and crushers (n = 3), participated. METHODS A tri-axial accelerometer was used to measure FTV in accordance with ISO 2631-1 guidelines. Frequency-weighted root-mean-square acceleration and the dominant frequency are reported. Participants were also asked to report pain/ache/discomfort in the hands and/or feet. RESULTS Reports of pain/discomfort/ache were highest in raise platform workers and jumbo drill operators who were exposed to FTV in the 40 Hz and 28 Hz range respectively. Reports of discomfort/ache/pain were lowest in the locomotive and crusher operators who were exposed to FTV below 10 Hz. These findings are consistent with animal studies that have shown vascular and neural damage in exposed appendages occurs at frequencies above 40 Hz. CONCLUSIONS Operators exposed to FTV at 40 Hz appear to be at greater risk of experiencing vibration induced injury. Future research is required to document the characteristics of FTV and epidemiological evidence is required to link exposure with injury. PMID:24004754

  4. Early photocycle structural changes in a bacteriorhodopsin mutant engineered to transmit photosensory signals.

    PubMed

    Sudo, Yuki; Furutani, Yuji; Spudich, John L; Kandori, Hideki

    2007-05-25

    Bacteriorhodopsin (BR) and sensory rhodopsin II (SRII) function as a light-driven proton pump and a receptor for negative phototaxis in haloarchaeal membranes, respectively. SRII transmits light signals through changes in protein-protein interaction with its transducer HtrII. Recently, we converted BR by three mutations into a form capable of transmitting photosignals to HtrII to mediate phototaxis responses. The BR triple mutant (BR-T) provides an opportunity to identify structural changes necessary to activate HtrII by comparing light-induced infrared spectral changes of BR, BR-T, and SRII. The hydrogen out-of-plane (HOOP) vibrations of the BR-T were very similar to those of SRII, indicating that they are distributed more extensively along the retinal chromophore than in BR, as in SRII. On the other hand, the bands of the protein moiety in BR-T are similar to those of BR, indicating that they are not specific to photosensing. The alteration of the O-H stretching vibration of Thr-204 in SRII, which we had previously shown to be essential for signal relay to HtrII, occurs also in BR-T. In addition, 1670(+)/1664(-) cm(-1) bands attributable to a distorted alpha-helix were observed in BR-T in a HtrII-dependent manner, as is seen in SRII. Thus, we identified similarities and dissimilarities of BR-T to BR and SRII. The results suggest signaling function of the structural changes of the HOOP vibrations, the O-H stretching vibration of the Thr-215 residue, and a distorted alpha-helix for the signal generation. We also succeeded in measurements of L minus initial state spectra of BR-T, which are the first FTIR spectra of L intermediates among sensory rhodopsins.

  5. Transfusion-transmitted infections

    PubMed Central

    Bihl, Florian; Castelli, Damiano; Marincola, Francesco; Dodd, Roger Y; Brander, Christian

    2007-01-01

    Although the risk of transfusion-transmitted infections today is lower than ever, the supply of safe blood products remains subject to contamination with known and yet to be identified human pathogens. Only continuous improvement and implementation of donor selection, sensitive screening tests and effective inactivation procedures can ensure the elimination, or at least reduction, of the risk of acquiring transfusion transmitted infections. In addition, ongoing education and up-to-date information regarding infectious agents that are potentially transmitted via blood components is necessary to promote the reporting of adverse events, an important component of transfusion transmitted disease surveillance. Thus, the collaboration of all parties involved in transfusion medicine, including national haemovigilance systems, is crucial for protecting a secure blood product supply from known and emerging blood-borne pathogens. PMID:17553144

  6. Sensitivity of mechanically transmitted pathogens to different disinfectants

    USDA-ARS?s Scientific Manuscript database

    The intensive hands-on activities of greenhouse tomato propagation and production favor the spread of mechanically transmitted pathogens, particularly Clavibacter michiganensis subsp. michiganensis (Cmm), viruses, viroids, and Botrytis cinerea. These pathogens can spread during crop handling, graft...

  7. Long-term daily vibration exposure alters current perception threshold (CPT) sensitivity and myelinated axons in a rat-tail model of vibration-induced injury.

    PubMed

    Krajnak, Kristine; Raju, Sandya G; Miller, G Roger; Johnson, Claud; Waugh, Stacey; Kashon, Michael L; Riley, Danny A

    2016-01-01

    Repeated exposure to hand-transmitted vibration through the use of powered hand tools may result in pain and progressive reductions in tactile sensitivity. The goal of the present study was to use an established animal model of vibration-induced injury to characterize changes in sensory nerve function and cellular mechanisms associated with these alterations. Sensory nerve function was assessed weekly using the current perception threshold test and tail-flick analgesia test in male Sprague-Dawley rats exposed to 28 d of tail vibration. After 28 d of exposure, Aβ fiber sensitivity was reduced. This reduction in sensitivity was partly attributed to structural disruption of myelin. In addition, the decrease in sensitivity was also associated with a reduction in myelin basic protein and 2',3'- cyclic nucleotide phosphodiasterase (CNPase) staining in tail nerves, and an increase in circulating calcitonin gene-related peptide (CGRP) concentrations. Changes in Aβ fiber sensitivity and CGRP concentrations may serve as early markers of vibration-induced injury in peripheral nerves. It is conceivable that these markers may be utilized to monitor sensorineural alterations in workers exposed to vibration to potentially prevent additional injury.

  8. Vibration manual

    NASA Technical Reports Server (NTRS)

    Green, C.

    1971-01-01

    Guidelines of the methods and applications used in vibration technology at the MSFC are presented. The purpose of the guidelines is to provide a practical tool for coordination and understanding between industry and government groups concerned with vibration of systems and equipments. Topics covered include measuring, reducing, analyzing, and methods for obtaining simulated environments and formulating vibration specifications. Methods for vibration and shock testing, theoretical aspects of data processing, vibration response analysis, and techniques of designing for vibration are also presented.

  9. Sexually transmitted diseases.

    PubMed

    Markle, William; Conti, Tracey; Kad, Manjusha

    2013-09-01

    Sexually transmitted infections (STIs), also referred to as sexually transmitted diseases, remain a growing worldwide problem and public health issue. This article covers the epidemiology of STIs, the history and physical findings, screening guidelines, and the general plan to combat STIs. Prevention is discussed using the latest information from the Centers for Disease Control and Prevention and other references. Infections discussed from the standpoint of cause, epidemiology, risk factors, clinical disease, diagnosis, and treatment include gonorrhea, Chlamydia trachomatis, Trichomonas vaginalis, syphilis, chancroid, Herpes simplex, lymphogranuloma venereum, granuloma inguinale, Herpes papilloma virus, Molluscum contagiosum, and pubic lice. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Infrared-Transmitting Fibers

    DTIC Science & Technology

    1998-08-01

    REFERENCES 1. J. S. Sanghera, V. Q. Nguyen, P. C. Pureza , , F. H. Kung, R. E. Miklos and I. D. Aggarwal, “Fabrication of Low-Loss IR-Transmitting...Ge30As10Se30Te30 Glass Fibers”, J. Lightwave Tech. 12, 737 (1994). 2. J. S. Sanghera, V. Q. Nguyen, P. C. Pureza , R. E. Miklos, F. H. Kung and I. D...Aggarwal, L. Busse, P. Pureza , V. Nguyen, R. Miklos, F. Kung and R. Mossadegh, “Development of Low Loss IR Transmitting Chalcogenide Glass Fibers”, Proc

  11. Distribution of mechanical impedance at the fingers and the palm of the human hand.

    PubMed

    Dong, R G; Wu, J Z; McDowell, T W; Welcome, D E; Schopper, A W

    2005-05-01

    A comprehensive understanding of the complex biodynamic response of the human fingers-hand-arm system may help researchers determine the causation of injuries arising from hand-transmitted vibration. This study theoretically demonstrates that the mechanical impedance (MI) in a hand power grip, as a measure of the biodynamic response of the system, can be divided into finger MI and palm MI. A methodology is developed to measure them separately and to investigate their distribution characteristics. This study involves 6 adult male subjects, constant-velocity sinusoidal excitations at 10 different discrete frequencies (16, 25, 40, 63, 100, 160, 250, 400, 630, 1000 Hz), and three different hand-handle coupling conditions. Our results suggest that at low frequencies (40 Hz), the palm MI is substantially higher than the finger MI; the majority of the hand MI remains distributed at the palm up to 100 Hz; and at frequencies higher than 160 Hz, the finger MI is comparable to or higher than the palm MI. Furthermore, at frequencies equal to or above 100 Hz, the finger MI is practically independent of the palm-handle coupling conditions. Knowledge of the MI distribution pattern may increase the understanding of vibration transmission to the hand and aid in the development of effective isolation devices.

  12. 3 degree of freedom hand controller

    NASA Technical Reports Server (NTRS)

    Menahem, Israel (Inventor)

    1992-01-01

    A hand controller which includes a hand grip having therein a gimble mechanism for allowing rotatory motion about three axes which intersect in the interior of the hand grip and from which motion transmitting members allow the motions about the three axes to be transmitted to remote pick off devices and also along which force feedback signals may be fedback to the gimble structure to provide the correct feel for the grip.

  13. Claw hand

    MedlinePlus

    Ulnar nerve palsy - claw hand; Ulnar nerve dysfunction - claw hand; Ulnar claw ... Someone can be born with claw hand (congenital), or they can develop it because of certain disorders, such as nerve injury.

  14. Hand transplantation.

    PubMed

    Amer, Hatem; Carlsen, Brian T; Dusso, Jennifer L; Edwards, Brooks S; Moran, Steven L

    2011-05-01

    The first successful hand transplant was performed in 1998, opening up a new possibility for patients who have suffered mutilating hand injuries. Since then, more than 60 such procedures have been performed throughout the world. This article describes the evolution of hand transplantation, outcomes of patients listed in the International Registry of Hand and Composite Tissue Transplantation, and ethical issues involved in hand transplantation. It also describes the hand transplantation program at Mayo Clinic, which was established in 2010.

  15. Sexually Transmitted Diseases

    DTIC Science & Technology

    1989-12-01

    12 Trichomoniasis...................................................... 13 Bacterial Vaginosis .. . . . . . . . . ...... 14...symptomatic relief and some cures 5. male partners of infected women should be treated with metronidazole 2 grams orally once Bacterial Vaginosis ...Diagnosis 114. Treatment 115. Bacterial vaginosis 116. Symptoms 117. Diagnosis 118. Treatment 119. Viral sexually transmitted diseases 120. Herpes

  16. Analyzing Vibrations in a Long Mast

    NASA Technical Reports Server (NTRS)

    Simpson, B.

    1984-01-01

    Report describes mathematical prediction and measurement of vibrations in light weight extensible mast of lattice structure. With mast suspended from 10 vertical wires, vibrations excited in horizontal plane by motor-driven mechanism or by hand. Vibrations recorded photographically and with accelerometers.

  17. Hand hygiene.

    PubMed

    Bolon, Maureen

    2011-03-01

    The toll of health care-associated infections on patients and the seeming ease of the procedure thought best able to prevent them have focused a spotlight onto hand hygiene performance. Poor performance of hand hygiene by health care workers inspires outrage in the general public. Much is understood regarding barriers to and motivators of hand hygiene performance. Guidelines encouraging use of alcohol-based hand hygiene agents have facilitated hand hygiene improvement efforts. These efforts and evidence that improved hand hygiene performance is associated with a reduction in health care-associated infections should encourage those in the hand hygiene campaigns.

  18. Sexually Transmitted Cervicitis

    PubMed Central

    Romanowski, Barbara

    1989-01-01

    Cervical infections with Neisseria gonorrhoeae, Chlamydia trachomatis, and Herpes simplex virus are some of the most common sexually transmitted infections. They are often asymptomatic, and therefore the patient is at risk of developing complications, such as pelvic inflammatory disease. It is important to recognize cervicitis, investigate it appropriately, and provide early treatment. Sexual partners must also be located and offered therapy to prevent re-infection in the index patient. PMID:21248969

  19. Preventing Sexually Transmitted Diseases

    PubMed Central

    Kieren, Dianne; Cumming, Ceinwen E.; Cumming, David C.

    1992-01-01

    The discouraging results of early efforts to educate the public about sexually transmitted diseases indicated that the goals of STD preventive action must be longer term and must change attitudes and behaviour as well as educate. They must also avoid an ostrich mentality about the sexual involvement of young people. This article examines more recent approaches to teaching about sexuality in general and STD prevention in particular. PMID:21221351

  20. Sexually Transmitted Infections.

    PubMed

    Smith, Lindsay; Angarone, Michael P

    2015-11-01

    Sexually transmitted infections (STIs) remain a significant burden on public health in the United States. Primary prevention counseling with early diagnosis and treatment remain the best methods to decrease the incidence of STIs. Through significant public heath interventions, the incidence of gonorrhea, Chlamydia, and trichomoniasis is decreasing; however, the incidence of primary and secondary syphilis is increasing. Human papilloma virus remains the most common STI, but new vaccinations have the possibility of having a significant impact on this virus's disease potential. This review discusses the most common STIs in the United States, focusing on clinical presentation, diagnosis, and treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. DOT Transmit Module

    NASA Technical Reports Server (NTRS)

    Quirk, Kevin J.; Gin, Jonathan W.; Sahasrabudhe, Adit; Patawaran, Ferze D.; Nguyen, Danh H.; Nguyen, Huy

    2013-01-01

    The Deep Space Optical Terminal (DOT) transmit module demonstrates the DOT downlink signaling in a flight electronics assembly that can be qualified for deep space. The assembly has the capability to generate an electronic pulse-position modulation (PPM) waveform suitable for driving a laser assembly to produce the optical downlink signal. The downlink data enters the assembly through a serializer/ deserializer (SERDES) interface, and is encoded using a serially concatenated PPM (SCPPM) forward error correction code. The encoded data is modulated using PPM with an inter-symbol guard time to aid in receiver synchronization. Monitor and control of the assembly is via a low-voltage differential signal (LVDS) interface

  2. Sexually transmitted diseases.

    PubMed

    Bechtel, Mark A; Trout, Wayne

    2015-03-01

    Sexually transmitted diseases (STDs) continue to be a global epidemic with significant risk of morbidity/mortality for the fetus. STDs with prominent cutaneous findings including condylomata acuminata, genital herpes infections, and syphilis are reviewed. Important clinical cutaneous findings help aid early diagnosis and facilitate treatment. Condylomata acuminata have the potential of causing cervical cancer, anogenital cancer, and oropharyngeal cancer. Significant advances have been made in human papilloma virus vaccinations and treatment. Genital herpes infection can produce significant physical and emotional distress to the patient and significant potential harm to the fetus. Early clinical recognition of STDs and their appropriate management is critical.

  3. Soil-Transmitted Helminth Infections

    MedlinePlus

    ... files Questions & answers Features Multimedia Contacts Soil-transmitted helminth infections Fact sheet Updated September 2017 Key facts Soil-transmitted helminth infections are caused by different species of parasitic ...

  4. 2012 Sexually Transmitted Diseases Surveillance

    MedlinePlus

    ... Special Profiles Census Regions National Overview National Profile Chlamydia Figures Gonorrhea Figures Syphilis Figures Other STDs Figures ... Transmitted Diseases (STDs), 2012 National Profile National Profile Chlamydia Gonorrhea Syphilis Other Sexually Transmitted Diseases Special Focus ...

  5. Cold Hands

    MedlinePlus

    ... you have a problem with the nerves or blood circulation or a problem with tissue damage in your hands or fingers. ... of causes. Having cold hands could signal a problem with your blood circulation or the blood vessels in your hands. Make ...

  6. Chapped hands

    MedlinePlus

    ... wind Avoid washing hands with hot water Limit hand washing as much as possible while maintaining good hygiene Try to keep the air in your home humid Use mild soaps or non-soap cleansers Use ... on your hands regularly, especially if you live in a dry ...

  7. [Hand osteoarthritis].

    PubMed

    Šenolt, Ladislav

    Hand osteoarthritis (OA) is a common chronic disorder causing pain and limitation of mobility of affected joints. The prevalence of hand OA increases with age and more often affects females. Clinical signs obviously do not correlate with radiographic findings - symptomatic hand OA affects approximately 26 % of adult subjects, but radiographic changes can be found in up to two thirds of females and half of males older than 55 years.Disease course differ among individual patients. Hand OA is a heterogeneous disease. Nodal hand OA is the most common subtype affecting interphalangeal joints, thumb base OA affects first carpometacarpal joint. Erosive OA represents a specific subtype of hand OA, which is associated with joint inflammation, more pain, functional limitation and erosive findings on radiographs.Treatment of OA is limited. Analgesics and nonsteroidal anti-inflammatory drugs are the only agents reducing symptoms. New insights into the pathogenesis of disease should contribute to the development of novel effective treatment of hand OA.

  8. Dose-response patterns for vibration-induced white finger

    PubMed Central

    Griffin, M; Bovenzi, M; Nelson, C

    2003-01-01

    Aims: To investigate alternative relations between cumulative exposures to hand-transmitted vibration (taking account of vibration magnitude, lifetime exposure duration, and frequency of vibration) and the development of white finger (Raynaud's phenomenon). Methods: Three previous studies have been combined to provide a group of 1557 users of powered vibratory tools in seven occupational subgroups: stone grinders, stone carvers, quarry drillers, dockyard caulkers, dockyard boilermakers, dockyard painters, and forest workers. The estimated total operating duration in hours was thus obtained for each subject, for each tool, and for all tools combined. From the vibration magnitudes and exposure durations, seven alternative measurements of cumulative exposure were calculated for each subject, using expressions of the form: dose = ∑amiti, where ai is the acceleration magnitude on tool i, ti is the lifetime exposure duration for tool i, and m = 0, 1, 2, or 4. Results: For all seven alternative dose measures, an increase in dose was associated with a significant increase in the occurrence of vibration-induced white finger, after adjustment for age and smoking. However, dose measures with high powers of acceleration (m > 1) faired less well than measures in which the weighted or unweighted acceleration, and lifetime exposure duration, were given equal weight (m = 1). Dose determined solely by the lifetime exposure duration (without consideration of the vibration magnitude) gave better predictions than measures with m greater than unity. All measures of dose calculated from the unweighted acceleration gave better predictions than the equivalent dose measures using acceleration frequency-weighted according to current standards. Conclusions: Since the total duration of exposure does not discriminate between exposures accumulated over the day and those accumulated over years, a linear relation between vibration magnitude and exposure duration seems appropriate for predicting

  9. Sexually transmitted diseases.

    PubMed

    Sulak, Patricia J

    2003-11-01

    Sexually transmitted diseases (STDs) constitute a major health burden in the United States, causing pelvic inflammatory disease, ectopic pregnancy, infertility, chronic pelvic pain, genital lesions, genital neoplasms, adverse pregnancy outcomes, immune system dysfunction, liver disease, and even death. STDs disproportionately affect adolescents and young adults. Of the estimated 15 million STDs that occur annually each year in the United States, 4 million are among adolescents and 6 million among young adults. The current epidemic is complicated by the high asymptomatic carrier state associated with most STDs and the inadequate protection of condoms in preventing transmission. Sexually active individuals, particularly adolescents, must be educated on the ramifications of early onset of sexual activity and the health consequences of multiple sexual partners.

  10. Sexually transmitted viruses.

    PubMed Central

    Rapp, F.

    1989-01-01

    Human viruses known to be spread by sexual contact include herpes simplex viruses (HSV), papillomaviruses (HPV), human immunodeficiency virus (HIV), hepatitis B virus, and cytomegalovirus. Infections with the first three (HSV, HPV, and HIV) have reached epidemic proportions and pose global health concerns. Most of what we know about these human pathogens has been learned only recently, owing to the advent of DNA technologies and advances in culture techniques. In fact, our awareness of one virally transmitted venereal disease, acquired immunodeficiency syndrome, dates to the early 1980s. This paper touches on various aspects of the biology, pathogenesis, clinical manifestations, and, where applicable, oncogenicity of these agents, as well as current treatments and vaccine initiatives. PMID:2549736

  11. Hand tremor and activity sensor

    NASA Technical Reports Server (NTRS)

    Konigsberg, E.

    1975-01-01

    System detects hand tremor and activity and transmitting signals over distance of at least 3 meters to receiver system. Designed for use in studies of effect of fatigue on individual's judgement or reaction time, sensor is installed within mounting of finger-ring; no external wiring or power source is needed.

  12. Laboratory and field measurements and evaluations of vibration at the handles of riveting hammers

    PubMed Central

    McDOWELL, THOMAS W.; WARREN, CHRISTOPHER; WELCOME, DANIEL E.; DONG, REN G.

    2015-01-01

    The use of riveting hammers can expose workers to harmful levels of hand-transmitted vibration (HTV). As a part of efforts to reduce HTV exposures through tool selection, the primary objective of this study was to evaluate the applicability of a standardized laboratory-based riveting hammer assessment protocol for screening riveting hammers. The second objective was to characterize the vibration emissions of reduced vibration riveting hammers and to make approximations of the HTV exposures of workers operating these tools in actual work tasks. Eight pneumatic riveting hammers were selected for the study. They were first assessed in a laboratory using the standardized method for measuring vibration emissions at the tool handle. The tools were then further assessed under actual working conditions during three aircraft sheet metal riveting tasks. Although the average vibration magnitudes of the riveting hammers measured in the laboratory test were considerably different from those measured in the field study, the rank orders of the tools determined via these tests were fairly consistent, especially for the lower vibration tools. This study identified four tools that consistently exhibited lower frequency-weighted and unweighted accelerations in both the laboratory and workplace evaluations. These observations suggest that the standardized riveting hammer test is acceptable for identifying tools that could be expected to exhibit lower vibrations in workplace environments. However, the large differences between the accelerations measured in the laboratory and field suggest that the standardized laboratory-based tool assessment is not suitable for estimating workplace riveting hammer HTV exposures. Based on the frequency-weighted accelerations measured at the tool handles during the three work tasks, the sheet metal mechanics assigned to these tasks at the studied workplace are unlikely to exceed the daily vibration exposure action value (2.5 m s−2) using any of the

  13. Laboratory and field measurements and evaluations of vibration at the handles of riveting hammers.

    PubMed

    McDowell, Thomas W; Warren, Christopher; Welcome, Daniel E; Dong, Ren G

    2012-10-01

    The use of riveting hammers can expose workers to harmful levels of hand-transmitted vibration (HTV). As a part of efforts to reduce HTV exposures through tool selection, the primary objective of this study was to evaluate the applicability of a standardized laboratory-based riveting hammer assessment protocol for screening riveting hammers. The second objective was to characterize the vibration emissions of reduced vibration riveting hammers and to make approximations of the HTV exposures of workers operating these tools in actual work tasks. Eight pneumatic riveting hammers were selected for the study. They were first assessed in a laboratory using the standardized method for measuring vibration emissions at the tool handle. The tools were then further assessed under actual working conditions during three aircraft sheet metal riveting tasks. Although the average vibration magnitudes of the riveting hammers measured in the laboratory test were considerably different from those measured in the field study, the rank orders of the tools determined via these tests were fairly consistent, especially for the lower vibration tools. This study identified four tools that consistently exhibited lower frequency-weighted and unweighted accelerations in both the laboratory and workplace evaluations. These observations suggest that the standardized riveting hammer test is acceptable for identifying tools that could be expected to exhibit lower vibrations in workplace environments. However, the large differences between the accelerations measured in the laboratory and field suggest that the standardized laboratory-based tool assessment is not suitable for estimating workplace riveting hammer HTV exposures. Based on the frequency-weighted accelerations measured at the tool handles during the three work tasks, the sheet metal mechanics assigned to these tasks at the studied workplace are unlikely to exceed the daily vibration exposure action value (2.5 m s(-2)) using any of the

  14. Robot Hand

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Robots are limited only by the dexterity of the hand. Dr. Salisbury, in conjunction with Stanford, Caltech and Jet Propulsion Laboratory, developed the Salisbury Hand which has three, three-jointed human-like fingers. The tips are covered with a resilient, high friction material for gripping. The robot hand can manipulate objects by finger motion, and adapts to different aims. Advanced software allows the hand to interpret information from fingertip sensors. Further development is expected. A company has been formed to reproduce the device; copies have been delivered to several laboratories.

  15. Cement mixing with vibrator

    SciTech Connect

    Allen, T.E.

    1991-07-09

    This patent describes a method of cementing a casing string in a bore hole of a well. It comprises introducing water and dry cement material into a mixing vessel; mixing the water and dry cement material in the mixing vessel to form a cement slurry, the slurry including lumps of the dry cement material, the mixing including steps of: agitating the slurry; and while agitating the slurry, transmitting vibrational energy into the slurry and thereby aiding disintegration and subsequent wetting of the lumps of the dry cement material in the slurry; and pumping the slurry into an annulus between the casing string and the bore hole.

  16. Texture-induced vibrations in the forearm during tactile exploration

    PubMed Central

    Delhaye, Benoit; Hayward, Vincent; Lefèvre, Philippe; Thonnard, Jean-Louis

    2012-01-01

    Humans can detect and discriminate between fine variations of surface roughness using active touch. It is hitherto believed that roughness perception is mediated mostly by cutaneous and subcutaneous afferents located in the fingertips. However, recent findings have shown that following abolishment of cutaneous afferences resulting from trauma or pharmacological intervention, the ability of subjects to discriminate between textures roughness was not significantly altered. These findings suggest that the somatosensory system is able to collect textural information from other sources than fingertip afference. It follows that signals resulting of the interaction of a finger with a rough surface must be transmitted to stimulate receptor populations in regions far away from the contact. This transmission was characterized by measuring in the wrist vibrations originating at the fingertip and thus propagating through the finger, the hand and the wrist during active exploration of textured surfaces. The spectral analysis of the vibrations taking place in the forearm tissues revealed regularities that were correlated with the scanned surface and the speed of exploration. In the case of periodic textures, the vibration signal contained a fundamental frequency component corresponding to the finger velocity divided by the spatial period of the stimulus. This regularity was found for a wide range of textural length scales and scanning velocities. For non-periodic textures, the spectrum of the vibration did not contain obvious features that would enable discrimination between the different stimuli. However, for both periodic and non-periodic stimuli, the intensity of the vibrations could be related to the microgeometry of the scanned surfaces. PMID:22783177

  17. Predicting and controlling risks from human exposures to vibration and mechanical shock: flag waving and flag weaving.

    PubMed

    Griffin, Michael J

    2015-01-01

    At work or in leisure activities, many people are exposed to vibration or mechanical shocks associated with risks of injury or disease. This paper identifies information that can be used to decide whether there may be a risk from exposure to hand-transmitted vibration or whole-body vibration and shock, and suggests actions that can control the risks. The complex and time-varying nature of human exposures to vibration and shock, the complexity of the different disorders and uncertainty as to the mechanisms of injury and the factors influencing injury have prevented the definition of dose-response relationships well proven by scientific study. It is necessary to wave a flag indicating when there is a need to control risks from exposure to vibration and shock while scientific enquiry provides understanding needed to weave a better flag. It is concluded that quantifying exposure severity is often neither necessary nor sufficient to either identify risks or implement measures that control the risks. The identification of risks associated with exposure to vibration and mechanical shock cannot, and need not, rely solely on the quantification of exposure severity. Qualitative methods can provide a sufficient indication of the need for control measures, which should not be restricted to reducing standardised measures of exposure severity.

  18. (Robotic hands)

    SciTech Connect

    Mann, R.C.

    1988-09-23

    The traveler attended the International Workshop on Robot Hands at the Palace Hotel in Dubrovnik, Yugoslavia. The traveler presented a lecture on An integrated sensor system for the ORNL mobile robot.'' The traveler obtained important information on current R D efforts in multi-fingered robot hands and object recognition using touch sensing.

  19. A longitudinal study of neck and upper limb musculoskeletal disorders and alternative measures of vibration exposure.

    PubMed

    Bovenzi, Massimo; Prodi, Andrea; Mauro, Marcella

    2016-08-01

    To investigate the exposure-response relationships between alternative frequency weightings of hand-transmitted vibration (HTV) and neck and upper limb musculoskeletal disorders (MSDs) in a cohort of HTV workers. In a three-year longitudinal study, the occurrence of neck and upper limb MSDs was investigated in 249 HTV workers and 138 control men. In the HTV workers, MSDs were related to measures of daily vibration exposure expressed in terms of 8-h energy-equivalent frequency-weighted acceleration magnitude [A(8)]. To calculate A(8), the acceleration magnitudes of vibration were weighted by means of four alternative frequency weightings of HTV. The associations between MSDs, individual characteristics, physical work load other than vibration, and psychological strain were also investigated. The occurrence of upper limb MSDs was greater in the HTV workers than in the controls. After adjustment for potential confounders, the occurrence of elbow/forearm and wrist/hand MSDs increased with the increase in vibration exposure. A measure of model selection did not reveal any substantial difference in the performance of the alternative frequency weightings of HTV for the prediction of neck and upper limb MSDs. In the study population, age, hard physical work load, and poor psychological well-being were associated with both neck and upper limb MSDs. In this study, there was evidence for significant exposure-response relationships between HTV exposure and MSDs in the distal sites of the upper limbs. There were no differences in the prediction of neck and upper limb MSDs between measures of daily vibration exposure calculated with alternative frequency weightings of acceleration magnitude.

  20. Measurement of biodynamic response of human hand arm system

    NASA Astrophysics Data System (ADS)

    Dong, R. G.; Welcome, D. E.; McDowell, T. W.; Wu, J. Z.

    2006-07-01

    Biodynamics of the human hand-arm system is one of the most important foundations for understanding hand-transmitted vibration exposure and its health effects. Considerable differences among the reported data of the biodynamic response (BR) of the hand-arm system have been observed. A significant portion of the differences are believed to have resulted from instrumentation problems and/or computational algorithm errors. To help establish a reliable and accurate methodology for BR measurement, this study addresses the fundamental instrumentation issues. Specifically, the general theory of the driving-point BR is reviewed and summarized. An accurate mass cancellation method for BR measurement is identified and further developed. A set of methods is proposed to systematically examine and calibrate the BR measurement system. Based on the experimental results and theoretical analyses, several instrumentation and algorithm problems are identified. This study demonstrated that the instrumentation problems can be resolved or avoided by appropriately selecting the force and motion sensors, improving the structure design of the instrumented handle and fixture, using the frequency-domain method for the handle mass cancellation, and conducting the static and dynamic calibrations of the measurement system using the proposed methods. The information and knowledge presented in this paper can help to generate reliable experimental data in further BR studies.

  1. Robotic Hand

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The Omni-Hand was developed by Ross-Hime Designs, Inc. for Marshall Space Flight Center (MSFC) under a Small Business Innovation Research (SBIR) contract. The multiple digit hand has an opposable thumb and a flexible wrist. Electric muscles called Minnacs power wrist joints and the interchangeable digits. Two hands have been delivered to NASA for evaluation for potential use on space missions and the unit is commercially available for applications like hazardous materials handling and manufacturing automation. Previous SBIR contracts resulted in the Omni-Wrist and Omni-Wrist II robotic systems, which are commercially available for spray painting, sealing, ultrasonic testing, as well as other uses.

  2. Actively controlled vibration welding system and method

    SciTech Connect

    Cai, Wayne W.; Kang, Bongsu; Tan, Chin-An

    2013-04-02

    A vibration welding system includes a controller, welding horn, an active material element, and anvil assembly. The assembly may include an anvil body connected to a back plate and support member. The element, e.g., a piezoelectric stack or shape memory alloy, is positioned with respect to the assembly. The horn vibrates in a desirable first direction to form a weld on a work piece. The element controls any vibrations in a second direction by applying calibrated response to the anvil body in the second direction. A method for controlling undesirable vibrations in the system includes positioning the element with respect to the anvil assembly, connecting the anvil body to the support member through the back plate, vibrating the horn in a desirable first direction, and transmitting an input signal to the element to control vibration in an undesirable second direction.

  3. Helicopter rotor blade design for minimum vibration

    NASA Technical Reports Server (NTRS)

    Taylor, R. B.

    1984-01-01

    The importance of blade design parameters in rotor vibratory response and the design of a minimum vibration blade based upon this understanding are examined. Various design approaches are examined for a 4 bladed articulated rotor operating at a high speed flight condition. Blade modal shaping, frequency placement, structural and aerodynamic coupling, and intermodal cancellation are investigated to systematically identify and evaluate blade design parameters that influence blade airloads, blade modal response, hub loads, and fuselage vibration. The relative contributions of the various components of blade force excitation and response to the vibratory hub loads transmitted to the fuselage are determined in order to isolate primary candidates for vibration alleviation. A blade design is achieved which reduces the predicted fuselage vibration from the baseline blade by approximately one half. Blade designs are developed that offer significant reductions in vibration (and fatigue stresses) without resorting to special vibration alleviation devices, radical blade geometries, or weight penalties.

  4. VIBRATION COMPACTION

    DOEpatents

    Hauth, J.J.

    1962-07-01

    A method of compacting a powder in a metal container is described including the steps of vibrating the container at above and below the resonant frequency and also sweeping the frequency of vibration across the resonant frequency several times thereby following the change in resonant frequency caused by compaction of the powder. (AEC)

  5. Vibration isolation

    NASA Technical Reports Server (NTRS)

    Bastin, Paul

    1990-01-01

    Viewgraphs on vibration isolation are presented. Techniques to control and isolate centrifuge disturbances were identified. Topics covered include: disturbance sources in the microgravity environment; microgravity assessment criteria; life sciences centrifuge; flight support equipment for launch; active vibration isolation system; active balancing system; and fuzzy logic control.

  6. Hand Eczema

    PubMed Central

    Agarwal, Uma Shankar; Besarwal, Raj Kumar; Gupta, Rahul; Agarwal, Puneet; Napalia, Sheetal

    2014-01-01

    Hand eczema is often a chronic, multifactorial disease. It is usually related to occupational or routine household activities. Exact etiology of the disease is difficult to determine. It may become severe enough and disabling to many of patients in course of time. An estimated 2-10% of population is likely to develop hand eczema at some point of time during life. It appears to be the most common occupational skin disease, comprising 9-35% of all occupational diseases and up to 80% or more of all occupational contact dermatitis. So, it becomes important to find the exact etiology and classification of the disease and to use the appropriate preventive and treatment measures. Despite its importance in the dermatological practice, very few Indian studies have been done till date to investigate the epidemiological trends, etiology, and treatment options for hand eczema. In this review, we tried to find the etiology, epidemiology, and available treatment modalities for chronic hand eczema patients. PMID:24891648

  7. Whole body vibration in mountain-rescue operations

    NASA Astrophysics Data System (ADS)

    Alberti, E.; Chiappa, D.; Moschioni, G.; Saggin, B.; Tarabini, M.

    2006-12-01

    In mountain-rescue operations injured people are generally exposed to vibrations and shocks that can be potential causes of physical conditions worsening. Such vibrations can derive both from patient's body manipulations (e.g. when it is being loaded and immobilized on a stretcher) and from forces coming from the transport devices and vehicles. Despite the general feeling that during this kind of operations the levels of transmitted vibrations to the injured can be quite large and potentially dangerous, there is practically no study in literature providing reliable parameters (i.e. measurements) to support or dismiss these beliefs. This paper reports the results of a measurement campaign carried-out in order to outline, identify and quantify the excitations a human body is exposed to, during typical transportation phases related to mountain-rescue operations. The work mainly presents and discusses the experimental setup with the aim of focusing on the problems related to this kind of measurements; the results of the experimental campaign carried-out for the measurement of the vibrations undergone by a human body during a simulated rescue operation are presented and discussed as well. Such simulation includes three phases of transportation: on a hand-held stretcher, on an ambulance and on a helicopter. The work is not intended to supply a complete characterization and analysis of vibrations transmission during any rescue operation but just to provide a preliminary overview and to define a measurement method that can be applied for a more comprehensive characterization. With such aims measurements were carried out in on-field situations stated as "typical" by rescue experts and data then analyzed both with standard procedures and algorithms (e.g. ISO 2631s weighting curves) and with the commonly used statistical indexes; in the analysis it is important to be aware that standardized measurement procedures and indexes, created to verify comfort or health-risks of

  8. Analyses of biodynamic responses of seated occupants to uncorrelated fore-aft and vertical whole-body vibration

    NASA Astrophysics Data System (ADS)

    Mandapuram, Santosh; Rakheja, Subhash; Marcotte, Pierre; Boileau, Paul-Émile

    2011-08-01

    The apparent mass and seat-to-head-transmissibility response functions of the seated human body were investigated under exposures to fore-aft ( x), vertical ( z), and combined fore-aft and vertical ( x and z) axis whole-body vibration. The coupling effects of dual-axis vibration were investigated using two different frequency response function estimators based upon the cross- and auto-spectral densities of the response and excitation signals, denoted as H1 and Hv estimators, respectively. The experiments were performed to measure the biodynamic responses to single and uncorrelated dual-axis vibration, and to study the effects of hands support, back support and vibration magnitude on the body interactions with the seatpan and the backrest, characterized in terms of apparent masses and the vibration transmitted to the head. The data were acquired with 9 subjects exposed to two different magnitudes of vibration applied along the individual x- and z-axis (0.25 and 0.4 m/s 2 rms), and along both the axis (0.28 and 0.4 m/s 2 rms along each axis) in the 0.5-20 Hz frequency range. The two methods resulted in identical single-axis responses but considerably different dual-axis responses. The dual-axis responses derived from the Hv estimator revealed notable effects of dual-axis vibration, as they comprised both the direct and cross-axis responses observed under single axis vibration. Such effect, termed as the coupling effect, was not evident in the dual-axis responses derived using the commonly used H1 estimator. The results also revealed significant effects of hands and back support conditions on the coupling effects and the measured responses. The back support constrained the upper body movements and thus showed relatively weaker coupling compared to that observed in the responses without the back support. The effect of hand support was also pronounced under the fore-aft vibration. The results suggest that a better understanding of the seated human body responses to

  9. Speech Intelligibility with a Bone Vibrator

    DTIC Science & Technology

    2005-04-01

    sciences cognitives BP 73, 91223 Brétigny sur Orge, France lpellieux@imassa.fr ABSTRACT The FELIN project (Foot soldier with Integrated Equipment...must be made to reach levels allowing for intelligibility in noisy environments (notably for use in armoured vehicles). INTRODUCTION Project FELIN ...contact with the skin . Mechanical vibrations are transmitted through the skin , towards skull bones. Parts of the vibrations are channeled through

  10. Materials Testing in Long Cane Design: Sensitivity, Flexibility, and Transmission of Vibration

    ERIC Educational Resources Information Center

    Rodgers, Mark D.; Emerson, Robert Wall

    2005-01-01

    Different materials that are used in manufacturing long cane shafts were assessed for their ability to transmit vibration and their sensitivity to tactile information, flexibility, and durability. It was found that the less flexible a cane shaft is, the better it transmits vibrations that are useful for discriminating surface textures and that…

  11. Changes in Sexually Transmitted Disease

    PubMed Central

    Hamilton-Smith, Barry

    1985-01-01

    Patterns of sexually transmitted diseases have changed, but the incidence has not decreased. The commonest STD (nonspecific urethritis) has only recently become reportable. The ratio of gonorrhea to NSU has reversed. Common childhood diseases have now become sexually transmitted diseases, for example, molluscum contagiosum and warts. Some venereal diseases have become less virulent, but acquired immune deficiency syndrome (AIDS) is almost uniformly fatal. Most infectious enteric diseases have now become sexually transmitted diseases. The key to eradicating STD is intelligent and persistent public health personnel. Some STD are multisystem diseases; a broad range of interested consultants will be useful to the family physician. PMID:21274065

  12. Statistics, Uncertainty, and Transmitted Variation

    SciTech Connect

    Wendelberger, Joanne Roth

    2014-11-05

    The field of Statistics provides methods for modeling and understanding data and making decisions in the presence of uncertainty. When examining response functions, variation present in the input variables will be transmitted via the response function to the output variables. This phenomenon can potentially have significant impacts on the uncertainty associated with results from subsequent analysis. This presentation will examine the concept of transmitted variation, its impact on designed experiments, and a method for identifying and estimating sources of transmitted variation in certain settings.

  13. Transfusion-transmitted Chagas' disease.

    PubMed

    Wendel, S

    1998-11-01

    Transfusion-transmitted Chagas' disease has been recognized since 1952. Until recently, no cases were reported outside of Latin America. However, emigration during the past 20 years expanded its transfusional geographic borders to North America. Trypanosoma cruzi-infected donors usually are asymptomatic, often for a lifetime. This situation complicates donor screening, particularly in regions where blood bank personnel are not familiar with the risk factors and natural history of this transfusion-transmitted infection. This review addresses the main aspects of epidemiology, risks of infection, clinical symptoms in donors and recipients, preventive measures, and blood donor screening to prevent transfusion-transmitted Chagas' disease.

  14. Hand reanimation.

    PubMed

    Dafydd, Hywel; Lin, Chih-Hung

    2014-03-01

    Brachial plexus disruption, major traumatic amputations, and Volkmann's contracture are all devastating injuries that present difficult reconstructive challenges. Advances in our understanding of nerve injury, regeneration, and refinement of microsurgical techniques have given rise to a number of therapeutic avenues over the last 4 decades. Hand reanimation aims to provide strength, stability, and mobility to a sensate hand. How this is achieved depends on a thorough understanding of the underlying pathophysiology, which in turn dictates what surgical modalities are suitable. Common to all reanimation procedures is the need to ensure full passive range of motion of the target joints prior to definitive surgery. Hand therapy is essential to prevent deleterious sequelae of injury, and to maximize rehabilitation following surgical reconstruction. Options for reanimation include nerve repair, nerve grafting, nerve transfer, tendon transfer, and free functioning muscle transfer.

  15. Laser-Based Measurement Of Torsional Vibration

    NASA Astrophysics Data System (ADS)

    Eastwood, P. G.; Halliwell, N. A.

    1986-07-01

    Investigations of the torsional vibration characteristics of shaft systems which transmit pulsating torques are an important part of a machinery designer's responsibility. Satisfactory operation of such systems depends to a large extent on successful treatment of this vibration problem, since incorrectly or insufficiently controlled torsional oscillations can lead to fatigue failure, rapid bearing wear, gear hammer etc. The problem is particularly severe in engine crankshaft design where numerous failures have been traced to abnormal vibration at "critical" speeds. Traditionally, the monitoring of torsional oscillation has been performed using strain gauges, slip rings and a variety of mechanical and electrical "torsiographs". More recently systems employing slotted discs or toothed wheels together with proximity transducers have been preferred, but a disadvantage arises from all these methods in that they require contact with the rotating component which necessitates "downtime" for transducer attachment. Moreover, physical access to the rotating surface is often restricted thus making the use of such methods impractical. The "cross-beam" laser velocimeter provides a means of measuring torsional vibration by a non-contact method, thus effectively overcoming the disadvantages of previous measurement systems. This well established laser-based instrument provides a time-resolved voltage analogue of shaft tangential surface velocity and laboratory and field tests have shown it to be both accurate and reliable. The versatility of this instrument, however, is restricted by the need for accurate positioning, since the velocimeter must be arranged so that the rotating surface always traverses the beam intersection region, which is typically only a fraction of a millimetre in length. As a consequence use is restricted to components of circular cross section. This paper compares and contrasts the "cross-beam" system with a new laser instrument, the laser torsional vibrometer

  16. [Hand infections].

    PubMed

    Schiele, Philippe; Le Nen, Dominique

    2013-11-01

    Superficial and deep hand infections are frequent in general medical practice. Clinical examination is a crucial step for an adapted provided care. Most of the time, surgery is the only way to heal infections. However, in some cases (like bites), empiric antibiotherapy is first indicated to limit infection. Staphyloccocus aureus as well as Group Beta Streptococcus are the most frequently pathogenes associated with hand infections. Methicillin resistant S. Aureus must always be considered in the diagnoses. Whatever treatment is provided, clinical assessement must be repeated within two days. An early adaquated treatment prevent functional complications and in some cases death of the patients.

  17. Sexually transmitted diseases in men.

    PubMed

    Phillips, Kenneth D; Dudgeon, Wesley D; Becker, Joel; Bopp, Christopher M

    2004-06-01

    Sexually transmitted diseases are the most common infectious diseases in the United States. Physicians, nurses, and other health care providers are uncomfortable discussing sexual issues with their clients. Therefore many health care needs are not addressed, and many opportunities for education aimed at preventing STDs are missed. In the periodic health history, the health care provider must elicit information about sexual practices (vaginal,oral, or anal intercourse), sexual orientation (heterosexual, homosexual, or bisexual), sexual risk behaviors (ie, unprotected intercourse with multiple partners), contraceptive use (particularly condoms), and prior STDs. Based on this information, the health care practitioner moves to more specific questions regarding sexual health. The health care practitioner asks about sores on the penis, dripping or discharge from the penis, staining of the underwear, testicular pain, and scrotal swelling. For the client who engages in oral sex, the health care practitioner asks about sore throat. For the client who engages in anal intercourse ask about diarrhea, rectal bleeding, anal itching, and pain. Probe the desire phase, the arousal phase (erection), and the ejaculation phase. Ask about the desire for fatherhood and concerns about fatherhood. An important part of health care is prevention. Culturally specific and sensitive information should be available for patients. Patient education should not consist of simply handing a brochure to a man. Using the brochure as a guide for including all the necessary information and ascertaining the man's understanding may be a very effective method of patient education. For men who are at increased risk for STDs or who present with symptoms of STDs, offering diagnostic testing is necessary. Men who have multiple sexual partners especially need diagnostic testing and prevention counseling. The CDC recommends annual HIV and hepatitis C testing for men who have sex with men and other men who have

  18. Analysis of different vibration patterns to guide blind people.

    PubMed

    Durá-Gil, Juan V; Bazuelo-Ruiz, Bruno; Moro-Pérez, David; Mollà-Domenech, Fernando

    2017-01-01

    The literature indicates the best vibration positions and frequencies on the human body where tactile information is transmitted. However, there is a lack of knowledge about how to combine tactile stimuli for navigation. The aim of this study is to compare different vibration patterns outputted to blind people and to determine the most intuitive vibration patterns to indicate direction for navigation purposes through a tactile belt. The vibration patterns that stimulate the front side of the waist are preferred for indicating direction. Vibration patterns applied on the back side of the waist could be suitable for sending messages such as stop.

  19. Analysis of different vibration patterns to guide blind people

    PubMed Central

    Bazuelo-Ruiz, Bruno; Moro-Pérez, David; Mollà-Domenech, Fernando

    2017-01-01

    The literature indicates the best vibration positions and frequencies on the human body where tactile information is transmitted. However, there is a lack of knowledge about how to combine tactile stimuli for navigation. The aim of this study is to compare different vibration patterns outputted to blind people and to determine the most intuitive vibration patterns to indicate direction for navigation purposes through a tactile belt. The vibration patterns that stimulate the front side of the waist are preferred for indicating direction. Vibration patterns applied on the back side of the waist could be suitable for sending messages such as stop. PMID:28348928

  20. Ectoparasites as sexually transmitted diseases.

    PubMed

    Routh, H B; Mirensky, Y M; Parish, L C; Witkowski, J A

    1994-12-01

    Although Sarcoptes scabii and Phthirus pubis infestations in humans are not always associated with the presence of other sexually transmitted diseases, usually they are. Therefore, patients presenting with scabies or P. pubis should be routinely tested for various sexually transmitted diseases. These very uncomfortable infestations are easily curable with proper therapy. Lindane 1% preparations effectively exterminate both vermin. We have not seen any resistant strains. Especially with P. pubis, all household contacts should be treated to avoid reinfestation.

  1. Vibrational Diver

    NASA Astrophysics Data System (ADS)

    Kozlov, Victor; Ivanova, Alevtina; Schipitsyn, Vitalii; Stambouli, Moncef

    2014-10-01

    The paper is concerned with dynamics of light solid in cavity with liquid subjected to rotational vibration in the external force field. New vibrational phenomenon - diving of a light cylinder to the cavity bottom is found. The experimental investigation of a horizontal annulus with a partition has shown that under vibration a light body situated in the upper part of the layer is displaced in a threshold manner some distance away from the boundary. In this case the body executes symmetric tangential oscillations. An increase of the vibration intensity leads to a tangential displacement of the body near the external boundary. This displacement is caused by the tangential component of the vibrational lift force, which appears as soon as the oscillations lose symmetry. In this case the trajectory of the body oscillatory motion has the form of a loop. The tangential lift force makes stable the position of the body on the inclined section of the layer and even in its lower part. A theoretical interpretation has been proposed, which explains stabilization of a quasi-equilibrium state of a light body near the cavity bottom in the framework of vibrational hydromechanics.

  2. Compact Active Vibration Control System for a Flexible Panel

    NASA Technical Reports Server (NTRS)

    Schiller, Noah H. (Inventor); Cabell, Randolph H. (Inventor); Perey, Daniel F. (Inventor)

    2014-01-01

    A diamond-shaped actuator for a flexible panel has an inter-digitated electrode (IDE) and a piezoelectric wafer portion positioned therebetween. The IDE and/or the wafer portion are diamond-shaped. Point sensors are positioned with respect to the actuator and measure vibration. The actuator generates and transmits a cancelling force to the panel in response to an output signal from a controller, which is calculated using a signal describing the vibration. A method for controlling vibration in a flexible panel includes connecting a diamond-shaped actuator to the flexible panel, and then connecting a point sensor to each actuator. Vibration is measured via the point sensor. The controller calculates a proportional output voltage signal from the measured vibration, and transmits the output signal to the actuator to substantially cancel the vibration in proximity to each actuator.

  3. Vocal Dose Measures: Quantifying Accumulated Vibration Exposure in Vocal Fold Tissues

    PubMed Central

    Titze, Ingo R.; Švec, Jan G.; Popolo, Peter S.

    2011-01-01

    To measure the exposure to self-induced tissue vibration in speech, three vocal doses were defined and described: distance dose, which accumulates the distance that tissue particles of the vocal folds travel in an oscillatory trajectory; energy dissipation dose, which accumulates the total amount of heat dissipated over a unit volume of vocal fold tissues; and time dose, which accumulates the total phonation time. These doses were compared to a previously used vocal dose measure, the vocal loading index, which accumulates the number of vibration cycles of the vocal folds. Empirical rules for viscosity and vocal fold deformation were used to calculate all the doses from the fundamental frequency (F0) and sound pressure level (SPL) values of speech. Six participants were asked to read in normal, monotone, and exaggerated speech and the doses associated with these vocalizations were calculated. The results showed that large F0 and SPL variations in speech affected the dose measures, suggesting that accumulation of phonation time alone is insufficient. The vibration exposure of the vocal folds in normal speech was related to the industrial limits for hand-transmitted vibration, in which the safe distance dose was derived to be about 500 m. This limit was found rather low for vocalization; it was related to a comparable time dose of about 17 min of continuous vocalization, or about 35 min of continuous reading with normal breathing and unvoiced segments. The voicing pauses in normal speech and dialogue effectively prolong the safe time dose. The derived safety limits for vocalization will likely require refinement based on a more detailed knowledge of the differences in hand and vocal fold tissue morphology and their response to vibrational stress, and on the effect of recovery of the vocal fold tissue during voicing pauses. PMID:12959470

  4. The effects of repetitive vibration on sensorineural function: biomarkers of sensorineural injury in an animal model of metabolic syndrome

    PubMed Central

    Kiedrowski, Megan; Waugh, Stacey; Miller, Roger; Johnson, Claud; Krajnak, Kristine

    2016-01-01

    Exposure to hand-transmitted vibration in the work-place can result in the loss of sensation and pain in workers. These effects may be exacerbated by pre-existing conditions such as diabetes or the presence of primary Raynaud's phenomena. The goal of these studies was to use an established model of vibration-induced injury in Zucker rats. Lean Zucker rats have a normal metabolic profile, while obese Zucker rats display symptoms of metabolic disorder or Type II diabetes. This study examined the effects of vibration in obese and lean rats. Zucker rats were exposed to 4 h of vibration for 10 consecutive days at a frequency of 125 Hz and acceleration of 49 m/s2 for 10 consecutive days. Sensory function was checked using transcutaneous electrical stimulation on days 1, 5 and 9 of the exposure. Once the study was complete the ventral tail nerves, dorsal root ganglia and spinal cord were dissected, and levels of various transcripts involved in sensorineural dysfunction were measured. Sensorineural dysfunction was assessed using transcutaneous electrical stimulation. Obese Zucker rats displayed very few changes in sensorineural function. However they did display significant changes in transcript levels for factors involved in synapse formation, peripheral nerve remodeling, and inflammation. The changes in transcript levels suggested that obese Zucker rats had some level of sensory nerve injury prior to exposure, and that exposure to vibration activated pathways involved in injury and re-innervation. PMID:26433044

  5. Ultrasound vibrometry using orthogonal- frequency-based vibration pulses.

    PubMed

    Zheng, Yi; Yao, Aiping; Chen, Shigao; Urban, Matthew W; Lin, Haoming; Chen, Xin; Guo, Yanrong; Chen, Ke; Wang, Tianfu; Chen, Siping

    2013-11-01

    New vibration pulses are developed for shear wave generation in a tissue region with preferred spectral distributions for ultrasound vibrometry applications. The primary objective of this work is to increase the frequency range of detectable harmonics of the shear wave. The secondary objective is to reduce the required peak intensity of transmitted pulses that induce the vibrations and shear waves. Unlike the periodic binary vibration pulses, the new vibration pulses have multiple pulses in one fundamental period of the vibration. The pulses are generated from an orthogonal-frequency wave composed of several sinusoidal signals, the amplitudes of which increase with frequency to compensate for higher loss at higher frequency in tissues. The new method has been evaluated by studying the shear wave propagation in in vitro chicken and swine liver. The experimental results show that the new vibration pulses significantly increase tissue vibration with a reduced peak ultrasound intensity, compared with the binary vibration pulses.

  6. Ultrasound Vibrometry Using Orthogonal Frequency Based Vibration Pulses

    PubMed Central

    Zheng, Yi; Yao, Aiping; Chen, Shigao; Urban, Matthew W.; Lin, Haoming; Chen, Xin; Guo, Yanrong; Chen, Ke; Wang, Tianfu; Chen, Shiping

    2014-01-01

    New vibration pulses are developed for shear wave generation in a tissue region with preferred spectral distributions for ultrasound vibrometry applications. The primary objective of this work is to increase the frequency range of detectable harmonics of the shear wave. The secondary objective is to reduce the required peak intensity of transmitted pulses that induce the vibrations and shear waves. Unlike the periodic binary vibration pulses, the new vibration pulses have multiple pulses in one fundamental period of the vibration. The pulses are generated from an orthogonal-frequency wave composed of several sinusoidal signals of which the amplitudes increase with frequency to compensate for higher loss at higher frequency in tissues. The new method has been evaluated by studying the shear wave propagation in in vitro chicken and swine liver. The experimental results show that the new vibration pulses significantly increase tissue vibration with a reduced peak ultrasound intensity, compared with the binary vibration pulses. PMID:24158291

  7. Random Vibrations

    NASA Technical Reports Server (NTRS)

    Messaro. Semma; Harrison, Phillip

    2010-01-01

    Ares I Zonal Random vibration environments due to acoustic impingement and combustion processes are develop for liftoff, ascent and reentry. Random Vibration test criteria for Ares I Upper Stage pyrotechnic components are developed by enveloping the applicable zonal environments where each component is located. Random vibration tests will be conducted to assure that these components will survive and function appropriately after exposure to the expected vibration environments. Methodology: Random Vibration test criteria for Ares I Upper Stage pyrotechnic components were desired that would envelope all the applicable environments where each component was located. Applicable Ares I Vehicle drawings and design information needed to be assessed to determine the location(s) for each component on the Ares I Upper Stage. Design and test criteria needed to be developed by plotting and enveloping the applicable environments using Microsoft Excel Spreadsheet Software and documenting them in a report Using Microsoft Word Processing Software. Conclusion: Random vibration liftoff, ascent, and green run design & test criteria for the Upper Stage Pyrotechnic Components were developed by using Microsoft Excel to envelope zonal environments applicable to each component. Results were transferred from Excel into a report using Microsoft Word. After the report is reviewed and edited by my mentor it will be submitted for publication as an attachment to a memorandum. Pyrotechnic component designers will extract criteria from my report for incorporation into the design and test specifications for components. Eventually the hardware will be tested to the environments I developed to assure that the components will survive and function appropriately after exposure to the expected vibration environments.

  8. Vibration on board and health effects.

    PubMed

    Jensen, Anker; Jepsen, Jørgen Riis

    2014-01-01

    There is only limited knowledge of the exposure to vibrations of ships' crews and their risk of vibration-induced health effects. Exposure to hand-arm vibrations from the use of vibrating tools at sea does not differ from that in the land-based trades. However, in contrast to most other work places, seafarers are also exposed to vibrations to the feet when standing on vibrating surfaces on board. Anecdotal reports have related the development of "white feet" to local exposure to vibration, e.g. in mining, but this connection has not been investigated in the maritime setting. As known from studies of the health consequences of whole body vibrations in land-transportation, such exposure at sea may affect ships' passengers and crews. While the relation of back disorders to high levels of whole body vibration has been demonstrated among e.g. tractor drivers, there are no reported epidemiological evidence for such relation among seafarers except for fishermen, who, however, are also exposed to additional recognised physical risk factors at work. The assessment and reduction of vibrations by naval architects relates to technical implications of this impact for the ships' construction, but has limited value for the estimation of health risks because they express the vibration intensity differently that it is done in a medical context.

  9. Surface acoustic wave (SAW) vibration sensors.

    PubMed

    Filipiak, Jerzy; Solarz, Lech; Steczko, Grzegorz

    2011-01-01

    In the paper a feasibility study on the use of surface acoustic wave (SAW) vibration sensors for electronic warning systems is presented. The system is assembled from concatenated SAW vibration sensors based on a SAW delay line manufactured on a surface of a piezoelectric plate. Vibrations of the plate are transformed into electric signals that allow identification of the sensor and localization of a threat. The theoretical study of sensor vibrations leads us to the simple isotropic model with one degree of freedom. This model allowed an explicit description of the sensor plate movement and identification of the vibrating sensor. Analysis of frequency response of the ST-cut quartz sensor plate and a damping speed of its impulse response has been conducted. The analysis above was the basis to determine the ranges of parameters for vibrating plates to be useful in electronic warning systems. Generally, operation of electronic warning systems with SAW vibration sensors is based on the analysis of signal phase changes at the working frequency of delay line after being transmitted via two circuits of concatenated four-terminal networks. Frequencies of phase changes are equal to resonance frequencies of vibrating plates of sensors. The amplitude of these phase changes is proportional to the amplitude of vibrations of a sensor plate. Both pieces of information may be sent and recorded jointly by a simple electrical unit.

  10. Surface Acoustic Wave (SAW) Vibration Sensors

    PubMed Central

    Filipiak, Jerzy; Solarz, Lech; Steczko, Grzegorz

    2011-01-01

    In the paper a feasibility study on the use of surface acoustic wave (SAW) vibration sensors for electronic warning systems is presented. The system is assembled from concatenated SAW vibration sensors based on a SAW delay line manufactured on a surface of a piezoelectric plate. Vibrations of the plate are transformed into electric signals that allow identification of the sensor and localization of a threat. The theoretical study of sensor vibrations leads us to the simple isotropic model with one degree of freedom. This model allowed an explicit description of the sensor plate movement and identification of the vibrating sensor. Analysis of frequency response of the ST-cut quartz sensor plate and a damping speed of its impulse response has been conducted. The analysis above was the basis to determine the ranges of parameters for vibrating plates to be useful in electronic warning systems. Generally, operation of electronic warning systems with SAW vibration sensors is based on the analysis of signal phase changes at the working frequency of delay line after being transmitted via two circuits of concatenated four-terminal networks. Frequencies of phase changes are equal to resonance frequencies of vibrating plates of sensors. The amplitude of these phase changes is proportional to the amplitude of vibrations of a sensor plate. Both pieces of information may be sent and recorded jointly by a simple electrical unit. PMID:22247694

  11. Transfusional transmitted viruses in pregnancy.

    PubMed

    Eleftheriou, A; Kalakoutis, G; Pavlides, N

    1998-01-01

    Blood has long been recognized as a vehicle for transmission of infectious organisms and as molecular laboratory technology has advanced, a seemingly endless array of infectious agents has occasionally been documented to be blood transmitted. Transfusion associated hepatitis (TAH) has been the most common serious consequence of blood transfusion although in recent years this has been significantly reduced (blood donor screening, blood processing, etc.). Thalassaemia major is classically associated with increased susceptibility to infections caused by those agents that are blood transmitted such as HBV, HCV, HIV, CMV, HPV B-19 (frequency rates vary from country to country). Monitoring the prevalence of transfusion transmitted infections in thalassaemics has been in recent years an indispensable part of their clinical management protocol. As a number of these viruses have been documented to be efficiently transmitted through the vertical route, the issue of blood transmitted viral infection monitoring becomes particularly important in order to provide protection or treatment both to the pregnant thalassaemic patient herself and to her foetus/newborn. Hepatitis (mainly B and C) and HIV in the obstetric thalassaemic is what the clinician is faced with most frequently. Although preventative measures have been very successful in the case of HBV infection and recently to an encouraging extent in the case of HIV (recommendations have been constructed), the mechanisms and frequency of HCV vertical transmission as well as the clinical outcome of children born to HCV carriers are not yet completely clarified. No vaccines are available and HIGB or antivirals do not appear to offer protection to the foetus against infection with HCV. Thalassaemics are frequently seropositive to markers of other transfusion transmitted viruses, such as CMV and HPV B-19, particularly by the age of pregnancy. Infection with a second or multiple strains as well as reactivation of existing CMV

  12. Approach in sexually transmitted diseases.

    PubMed

    Belda Junior, Walter; Shiratsu, Ricardo; Pinto, Valdir

    2009-01-01

    Nowadays, sexually transmitted diseases are one of the most common public health issues. Among its consequences are the possibility of transmission from mother to baby - which may cause miscarriages and congenital disease, male and female infertility, and the increase of HIV infection risk. Therefore, the main goal of these guidelines is to contribute to the improvement of the treatment for sexually transmitted diseases patients by presenting to the medical community how today's science stands on the matter and also what the recommendation for diagnosing and treating a patient are.

  13. Sexually transmitted diseases treatment guidelines.

    PubMed

    Burstein, Gale R; Workowski, Kimberly A

    2003-08-01

    Sexually transmitted diseases (STDs) are a major health problem for adolescents. Health care providers for adolescents play a critical role in preventing and treating STDs. In May 2002, the Centers for Disease Control and Prevention published the Sexually Transmitted Diseases Treatment Guidelines 2002. These evidence-based guidelines are based on a systematic literature review focusing on information that had become available since the 1998 Guidelines for Treatment of STDs. This article reviews the new STD treatment guidelines for gonorrhea, chlamydia, bacterial vaginosis, trichomonas, vulvovaginal candidiasis, pelvic inflammatory disease, genital warts, herpes simplex virus infection, syphilis, and scabies. Although these guidelines emphasize treatment, prevention strategies and diagnostic recommendations also are discussed.

  14. Work ability in vibration-exposed workers.

    PubMed

    Gerhardsson, L; Hagberg, M

    2014-12-01

    Hand-arm vibration exposure may cause hand-arm vibration syndrome (HAVS) including sensorineural disturbances. To investigate which factors had the strongest impact on work ability in vibration-exposed workers. A cross-sectional study in which vibration-exposed workers referred to a department of occupational and environmental medicine were compared with a randomized sample of unexposed subjects from the general population of the city of Gothenburg. All participants underwent a structured interview, answered several questionnaires and had a physical examination including measurements of hand and finger muscle strength and vibrotactile and thermal perception thresholds. The vibration-exposed group (47 subjects) showed significantly reduced sensitivity to cold and warmth in digit 2 bilaterally (P < 0.01) and in digit 5 in the left hand (P < 0.05) and to warmth in digit 5 in the right hand (P < 0.01), compared with the 18 referents. Similarly, tactilometry showed significantly raised vibration perception thresholds among the workers (P < 0.05). A strong relationship was found for the following multiple regression model: estimated work ability = 11.4 - 0.1 × age - 2.3 × current stress level - 2.5 × current pain in hands/arms (multiple r = 0.68; P < 0.001). Vibration-exposed workers showed raised vibrotactile and thermal perception thresholds, compared with unexposed referents. Multiple regression analysis indicated that stress disorders and muscle pain in hands/arms must also be considered when evaluating work ability among subjects with HAVS. © The Author 2014. Published by Oxford University Press on behalf of the Society of Occupational Medicine.

  15. The effects of whole body vibration on EMG activity of the upper extremity muscles in static modified push up position.

    PubMed

    Ashnagar, Zinat; Shadmehr, Azadeh; Hadian, Mohammadreza; Talebian, Saeed; Jalaei, Shohreh

    2016-08-10

    Whole Body Vibration (WBV) has been reported to change neuromuscular activity which indirectly assessed by electromyography (EMG). Although researches regarding the influence of WBV on EMG activity of the upper extremity muscles are in their infancy, contradictory findings have been reported as a result of dissimilar protocols. The purpose of this study was to investigate the effects of WBV on electromyography (EMG) activity of upper extremity muscles in static modified push up position. Forty recreationally active females were randomly assigned in WBV and control groups. Participants in WBV group received 5 sets of 30 seconds vibration at 5 mm (peak to peak) and 30 Hz by using vibratory platform. No vibration stimulus was used in the control group. Surface EMG was recorded from Upper Trapezius (UT), Serratus Anterior (SA), Biceps Brachii (BB) and Triceps Brachii (TB) muscles before, during and after the vibration protocol while the subjects maintained the static modified push up position. EMG signals were expressed as root mean square (EMGrms) and normalized by maximum voluntary exertion (MVE). EMGrms activity of the studied muscles increased significantly during the vibration protocol in the WBV group comparing to the control group (P ≤ 0.05). The results indicated that vibration stimulus transmitting via hands increased muscle activity of UT, SA, BB and TB muscles by an average of 206%, 60%, 106% and 120%, respectively, comparing to pre vibration values. These findings suggest that short exposure to the WBV could increase the EMGrms activity of the upper extremity muscles in the static modified push-up position. However, more sessions of WBV application require for a proper judgment.

  16. Vibrational spectroscopy

    Treesearch

    Umesh P. Agarwal; Rajai Atalla

    2010-01-01

    Vibrational spectroscopy is an important tool in modern chemistry. In the past two decades, thanks to significant improvements in instrumentation and the development of new interpretive tools, it has become increasingly important for studies of lignin. This chapter presents the three important instrumental methods-Raman spectroscopy, infrared (IR) spectroscopy, and...

  17. Force-limited vibration tests aplied to the FORTE` satellite

    SciTech Connect

    Stevens, R.R.; Butler, T.A.

    1996-02-01

    A force limited random vibration test was conducted on a small satellite called FORTE{prime}. This type of vibration test reduces the over testing that can occur in a conventional vibration test. Two vibration specifications were used in the test: The conventional base acceleration specification, and an interface force specification. The vibration level of the shaker was controlled such that neither the table acceleration nor the force transmitted to the test item exceeded its specification. The effect of limiting the shake table vibration to the force specification was to reduce (or ``notch``) the shaker acceleration near some of the satellite`s resonance frequencies. This paper describes the force limited test conducted for the FORTE{prime} satellite. The satellite and its dynamic properties are discussed, and the concepts of force limiting theory are summarized. The hardware and setup of the test are then described, and the results of the force limited vibration test are discussed.

  18. Two-Stage Passive Vibration Isolator

    NASA Technical Reports Server (NTRS)

    Goullioud, Renaud; Gursel, Yekta; Neville, Timothy; Bronowicki, Allen J.; Platus, David; MacDonald, Rhonda

    2008-01-01

    The design and testing of a structural system were implemented to hold the optics of the planned Space Interferometry Mission (SIM) at positions and orientations characterized by vibrational translation and rotation errors of no more than a few nanometers or a few milliarcseconds, respectively. Much of the effort was devoted to a test bed for verifying the predicted behavior of a vibration- isolation structural subsystem working together with an active control system for positioning and orienting the SIM optics. There was considerable emphasis on the vibration-isolation subsystem, which was passive and comprised two stages. The main sources of vibration were six reaction wheels in an assembly denoted the "backpack." The first vibration-isolation stage consisted of hexapod isolator mounts - one for each reaction wheel - characterized by a natural vibration frequency of 10 Hz. The second stage was a set of three beams, disposed between the backpack and the structure that held the SIM optics, that were flexured such that they transmitted only bending loads, with a natural vibrational frequency and damping of about 5 Hz and 4 percent, respectively. Preliminary test results were presented and characterized as demonstrating the effectiveness of the two-stage vibration-isolation design.

  19. Using Piezoelectric Devices to Transmit Power through Walls

    NASA Technical Reports Server (NTRS)

    Sherrit, Stewart; Bar-Cohen, Yoseph; Bao, Xiaoqi

    2008-01-01

    A method denoted wireless acoustic-electric feed-through (WAEF) has been conceived for transmitting power and/or data signals through walls or other solid objects made of a variety of elastic materials that could be electrically conductive or nonconductive. WAEF would make it unnecessary to use wires, optical fibers, tubes, or other discrete wall-penetrating signal-transmitting components, thereby eliminating the potential for structural weakening or leakage at such penetrations. Avoidance of such penetrations could be essential in some applications in which maintenance of pressure, vacuum, or chemical or biological isolation is required. In a basic WAEF setup, a transmitting piezoelectric transducer on one side of a wall would be driven at resonance to excite ultrasonic vibrations in the wall. A receiving piezoelectric transducer on the opposite side of the wall would convert the vibrations back to an ultrasonic AC electric signal, which would then be detected and otherwise processed in a manner that would depend on the modulation (if any) applied to the signal and whether the signal was used to transmit power, data, or both. An electromechanical-network model has been derived as a computationally efficient means of analyzing and designing a WAEF system. This model is a variant of a prior model, known in the piezoelectric-transducer art as Mason's equivalent-circuit model, in which the electrical and mechanical dynamics, including electromechanical couplings, are expressed as electrical circuit elements that can include inductors, capacitors, and lumped-parameter complex impedances. The real parts of the complex impedances are used to account for dielectric, mechanical, and coupling losses in all components (including all piezoelectric-transducer, wall, and intermediate material layers). In an application to a three-layer piezoelectric structure, this model was shown to yield the same results as do solutions of the wave equations of piezoelectricity and acoustic

  20. Calibration of sound and vibration sensors and vibration testing systems

    NASA Astrophysics Data System (ADS)

    Nicklich, Holger

    2004-08-01

    SPEKTRA is a manufacturer of high quality calibration systems for sound and vibration. Under license No DKD-K-27801, a calibration lab was established at SPEKTRA to provide a calibration service. The paper gives a summary of 4 years experience in the calibration of vibration Sensors, measuring systems and vibration test equipment in the industrial field. In practice calibration is often treated as an unpleasant job that is solved by handing out a “Calibration certificate of every part of the system” to the Quality Manager. The paper comes to the conclusion that calibration can help to minimize costs and risks if the customer has basic knowledge in international standards, the used test equipment and the special requirements for testing with this configuration. It is not enough to calibrate one sensor of a system in a standard range. The requirements for calibration should be defined individually for every testing system and application.

  1. Calibration of Sound and Vibration Sensors and Vibration Testing Systems

    NASA Astrophysics Data System (ADS)

    Nicklich, H.

    2004-08-01

    SPEKTRA is a manufacturer of high quality calibration systems for sound and vibration. Under license No DKD-K-27801, a calibration lab was established at SPEKTRA to provide a calibration service. The paper gives a summary of 4 years experience in the calibration of vibration Sensors, measuring systems and vibration test equipment in the industrial field. In practice calibration is often treated as an unpleasant job that is solved by handing out a "Calibration certificate of every part of the system" to the Quality Manager. The paper comes to the conclusion that calibration can help to minimize costs and risks if the customer has basic knowledge in international standards, the used test equipment and the special requirements for testing with this configuration. It is not enough to calibrate one sen- sor of a system in a standard range. The requirements for calibration should be defined individually for every testing system and application.

  2. Good Vibrations

    NASA Technical Reports Server (NTRS)

    2001-01-01

    A Small Business Innovation Research (SBIR) sponsorship from NASA's Dryden Flight Research Center, assisted MetroLaser, of Irvine, California, in the development of a self-aligned laser vibrometer system. VibroMet, capable of measuring surface vibrations in a variety of industries, provides information on the structural integrity and acoustical characteristics of manufactured products. This low-cost, easy-to-use sensor performs vibration measurement from distances of up to three meters without the need for adjustment. The laser beam is simply pointed at the target and the system then uses a compact laser diode to illuminate the surface and to subsequently analyze the reflected light. The motion of the surface results in a Doppler shift that is measured with very high precision. VibroMet is considered one of the many behind-the-scenes tools that can be relied on to assure the quality, reliability and safety of everything from airplane panels to disk brakes

  3. Sexually transmitted diseases and infertility.

    PubMed

    Tsevat, Danielle G; Wiesenfeld, Harold C; Parks, Caitlin; Peipert, Jeffrey F

    2017-01-01

    Female infertility, including tubal factor infertility, is a major public health concern worldwide. Most cases of tubal factor infertility are attributable to untreated sexually transmitted diseases that ascend along the reproductive tract and are capable of causing tubal inflammation, damage, and scarring. Evidence has consistently demonstrated the effects of Chlamydia trachomatis and Neisseria gonorrhoeae as pathogenic bacteria involved in reproductive tract morbidities including tubal factor infertility and pelvic inflammatory disease. There is limited evidence in the medical literature that other sexually transmitted organisms, including Mycoplasma genitalium, Trichomonas vaginalis, and other microorganisms within the vaginal microbiome, may be important factors involved in the pathology of infertility. Further investigation into the vaginal microbiome and other potential pathogens is necessary to identify preventable causes of tubal factor infertility. Improved clinical screening and prevention of ascending infection may provide a solution to the persistent burden of infertility. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Contraception and sexually transmitted diseases.

    PubMed

    Creatsas, G

    1997-12-01

    The needs for contraception are increasing world-wide as more women desire protection from unwanted pregnancies. Since the incidence of sexually transmitted diseases (STDs) has increased in many countries, consultation for contraception should be provided together with that on STDs. Each woman may choose the contraceptive method according to her needs but she should also be informed about the beneficial and negative effects of the method in preventing STDs.

  5. Confocal microscopy in transmitted light

    NASA Astrophysics Data System (ADS)

    Dodt, Hans-Ulrich; Becker, Klaus

    2003-10-01

    We developed a confocal microscope for transmitted light to visualize fine details in phase objects like unstained biological specimens. The main difficulty of confocal microscopy in transmission is the alignment of illumination and detector pinholes. This alignment was achieved by using "electronic pinholes" on the detector side. As a first step, we were able to image cells in onion skin at greater depths and with higher resolution than by using conventional microscopy.

  6. The new MTLRS transmitting system

    NASA Technical Reports Server (NTRS)

    Sperber, Peter; Hessels, U.; Motz, R.; Beek, Wiard; Offierski, Jacek W.; Vanes, C.

    1993-01-01

    This paper presents a detailed description about the new transmitting system of the Modular Transportable Laser Ranging Systems MTLRS-1/2. A simplified theory of the Self Filtering Unstable Resonator (SFUR) is explained. Laser design details are discussed concerning the extreme environmental conditions in which these mobile systems are operating. Details are given concerning the new avalanche START detector. The new SFUR laser and START detector are necessary parts in order to bring both mobile systems towards 1 cm ranging accuracy.

  7. Reductions in finger blood flow induced by 125-Hz vibration: effect of location of contact with vibration.

    PubMed

    Ye, Ying; Griffin, Michael J

    2016-04-01

    This study investigated whether the reductions in finger blood flow induced by 125-Hz vibration applied to different locations on the hand depend on thresholds for perceiving vibration at these locations. Subjects attended three sessions during which vibration was applied to the right index finger, the right thenar eminence, or the left thenar eminence. Absolute thresholds for perceiving vibration at these locations were determined. Finger blood flow in the middle finger of both hands was then measured at 30-s intervals during five successive 5-min periods: (i) pre-exposure, (ii) pre-exposure with 2-N force, (iii) 2-N force with vibration, (iv) post-exposure with 2-N force, (v) recovery. During period (iii), vibration was applied at 15 dB above the absolute threshold for perceiving vibration at the right thenar eminence. Vibration at all three locations reduced finger blood flow on the exposed and unexposed hand, with greater reductions when vibrating the finger. Vibration-induced vasoconstriction was greatest for individuals with low thresholds and locations of excitation with low thresholds. Differences in vasoconstriction between subjects and between locations are consistent with the Pacinian channel mediating both absolute thresholds and vibration-induced vasoconstriction.

  8. Effects Of Vibrations On Grasp Control

    NASA Technical Reports Server (NTRS)

    Hannaford, Blake; Rosar, William H.

    1989-01-01

    Vibration powerful and specific stimulus to low-level reflex behavior. Report describes experiments on interactions between human operators and hand control device for control of extent of opening and gripping force of remote gripper. Major purpose of study to determine effects of vibrations in device upon ability of operators to control gripping force. Used beneficially in design of controls to provide warning signals preventing operators from commanding excessive, or perhaps insufficient forces.

  9. Circuit For Control Of Electromechanical Prosthetic Hand

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr.

    1995-01-01

    Proposed circuit for control of electromechanical prosthetic hand derives electrical control signals from shoulder movements. Updated, electronic version of prosthesis, that includes two hooklike fingers actuated via cables from shoulder harness. Circuit built around favored shoulder harness, provides more dexterous movement, without incurring complexity of computer-controlled "bionic" or hydraulically actuated devices. Additional harness and potentiometer connected to similar control circuit mounted on other shoulder. Used to control stepping motor rotating hand about prosthetic wrist to one of number of angles consistent with number of digital outputs. Finger-control signals developed by circuit connected to first shoulder harness transmitted to prosthetic hand via sliprings at prosthetic wrist joint.

  10. Circuit For Control Of Electromechanical Prosthetic Hand

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr.

    1995-01-01

    Proposed circuit for control of electromechanical prosthetic hand derives electrical control signals from shoulder movements. Updated, electronic version of prosthesis, that includes two hooklike fingers actuated via cables from shoulder harness. Circuit built around favored shoulder harness, provides more dexterous movement, without incurring complexity of computer-controlled "bionic" or hydraulically actuated devices. Additional harness and potentiometer connected to similar control circuit mounted on other shoulder. Used to control stepping motor rotating hand about prosthetic wrist to one of number of angles consistent with number of digital outputs. Finger-control signals developed by circuit connected to first shoulder harness transmitted to prosthetic hand via sliprings at prosthetic wrist joint.

  11. Adolescents and sexually transmitted diseases.

    PubMed

    Yarber, W L; Parrillo, A V

    1992-09-01

    Sexually transmitted diseases (STDs) are a serious health problem for adolescents, occurring in an estimated one-quarter of sexually active teen-agers. Many of the health problems--including STDs--result from specific risk-taking behaviors. Determinants of STD risks among adolescents include behavioral, psychological, social, biological, institutional factors. Education is an important component in STD control in adolescents. The goal of education is to increase adolescent self-efficiency in practicing STD prevention and risk-reduction. A comprehensive approach including quality, theory-based education, accessible and effective health clinics, and improved social and economic conditions has the most promise of controlling STDs in adolescents.

  12. [Tularemia transmitted by arthropod bites].

    PubMed

    Misić-Majerus, L; Bujić, N; Madarić, V

    1996-01-01

    The authors present four patients affected with tularaemia in Koprivnica-Krizevci region. The disease occurred in the period from April to September 1994, in 3 males and 1 female patient, aged 9-49 years. In all affected persons the infections were transmitted after bites of arthropods, ticks or other insects. The disease was clinically manifested as ulceroglandular form, without complications and relapses. The diagnosis was established by anamnestic and epidemiological data, clinical picture, the course of the disease, laboratory findings, tularin test and specific agglutination test (two samples). All patients were successfully treated with doxycyclin.

  13. Zika Mosquito Can Transmit Other Viruses, Too

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_165752.html Zika Mosquito Can Transmit Other Viruses, Too 3-in- ... mosquito species that's the main carrier of the Zika virus might also transmit two other viruses -- chikungunya ...

  14. Sexually transmitted diseases in pregnancy.

    PubMed

    Ross, S M

    1982-12-01

    Numerous sexually transmitted diseases--syphilis, gonococcal infections, group B beta-hemolytic streptococcal infection, chlamydial infections, mycoplasmas, herpes simplex virus, cytomegalovirus infections, hepatitis B viral infections, fungal infection, trichomonas vaginalis, condylomata acuminata, and scabies--are of concern when they occur during pregnancy, either because of their potential adverse effects on the fetus or the chance of a modified reaction in the pregnant woman. This article discusses each of these venereal diseases in turn, providing information on diagnosis, prevention, and treatment. Pregnancy appears to have a benign effect on syphilis in the mother, but the fetus is likely to suffer from abortion, intrauterine death, intrauterine growth retardation, and congenital syphilis, underscoring the need for serologic testing of symptomatic pregnant women and treatment with penicillin. Neisseria gonorrhoea, still a prevalent sexually transmitted disease among women of childbearing age, is of considerable seriousness during pregnancy due to the risk of contamination of the newborn during passage through the birth canal. Infants delivered of women infected with chlamydia may develop a neonatal inclusion conjunctivitis, nasopharygitis, otitis media, or an afebrile pneumonia syndrome.

  15. [Sexually transmitted diseases and travel].

    PubMed

    Halioua, B; Prazuck, T; Malkin, J E

    1997-01-01

    Travelers are highly exposed to acquiring sexually transmitted diseases especially since the most popular destinations are high risk areas. While this risk applies to all travelers, it is highest for the "sex" tourist who is typically a male with a mean age of 38 years. Awareness of risks is still incomplete, especially with regard to HIV. Several studies have shown that only 20% to 70% of travelers use condoms. This finding accounts for the high incidence of sexually transmitted diseases in returning travelers: 2% to 10%. The risk of HIV infection is particularly high for persons living abroad. Based on available data, we can define the typical profile of the high risk traveler who should be targeted for prevention. Prevention depends on providing adequate information before departure, especially concerning HIV infection. Use of a condom throughout sexual contact is a basic safety rule. However condom quality is poor in many developing countries. Returning travelers should seek medical advice if manifestations involving the anogenital regions should appear.

  16. Identification of vibration sources in pulse tube cryogenic refrigerator

    NASA Astrophysics Data System (ADS)

    Riabzev, S. V.; Veprik, A. M.; Vilenchik, H. S.; Pundak, N.

    2007-04-01

    As is known, a cold finger of a pulse tube cryogenic refrigerator does not contain moving mechanical components and, therefore, is traditionally thought of as producing low vibration and having extended lifespan. Because of these outstanding features, such cryogenic engines are especially attractive for use in a variety of vibration-sensitive instrumentation, such as infra-red imagers, scanning electron microscopes (SEM), superconductive quantum interference devices (SQUID), etc. However, even relatively low-level vibration produced by a cold tip of a pulse tube, resulting from oscillation of a gas pressure along with a vibration transmitted from a compressor through a metallic gas transfer tube, may sometimes appear to be excessive for the above vibration-sensitive applications. By making an extensive use of the finite element analysis supported by the full-scale experimentation, the authors are attempting to identify the sources of vibration occurring in a cold tip of a pulse tube.

  17. Violin bow vibrations.

    PubMed

    Gough, Colin E

    2012-05-01

    The modal frequencies and bending mode shapes of a freely supported tapered violin bow are investigated by finite element analysis and direct measurement, with and without tensioned bow hair. Such computations are used with analytic models to model the admittance presented to the stretched bow hairs at the ends of the bow and to the string at the point of contact with the bow. Finite element computations are also used to demonstrate the influence of the lowest stick mode vibrations on the low frequency bouncing modes, when the hand-held bow is pressed against the string. The possible influence of the dynamic stick modes on the sound of the bowed instrument is briefly discussed.

  18. Sexually transmitted diseases in children in India.

    PubMed

    Dhawan, Jyoti; Gupta, Somesh; Kumar, Bhushan

    2010-01-01

    Sexually transmitted diseases (STDs) in children are not uncommon in India, though systematic epidemiological studies to determine the exact prevalence are not available. STDs in children can be acquired via sexual route or, uncommonly, via non-sexual route such as accidental inoculation by a diseased individual. Neonatal infections are almost always acquired intrauterine or during delivery. Voluntary indulgence in sexual activity is also an important factor in acquisition of STDs in childhood. Sexual abuse and sex trafficking remain the important problems in India. Surveys indicate that nearly half of the children are sexually abused. Most at risk children are street-based, homeless or those living in or near brothels. Last two decades have shown an increase in the prevalence of STDs in children, though most of the data is from northern part of the country and from major hospitals. However, due to better availability of antenatal care to majority of women, cases of congenital syphilis have declined consistently over the past two-three decades. Other bacterial STDs are also on decline. On the other hand, viral STDs such as genital herpes and anogenital warts are increasing. This reflects trends of STDs in the adult population. Concomitant HIV infection is uncommon in children. Comprehensive sex education, stringent laws to prevent sex trafficking and child sexual abuse, and antenatal screening of all the women can reduce the prevalence of STDs in children.

  19. Investigation of the effect of vibration amplitude on vibration measurements of polarimetric fiber sensors embedded in composite beams

    NASA Astrophysics Data System (ADS)

    Ramakrishnan, Manjusha; Rajan, Ginu; Semenova, Yuliya; Callaghan, Dean; Farrell, Gerald

    2014-04-01

    Glass fiber reinforced composite material beams embedded with two types of polarimetric sensors are fabricated by the hand layup method and characterized. Two types of polarimetric sensors, a high strain sensitive Panda type fiber and a low strain sensitive polarization maintaining photonic crystal fiber (PM-PCF), are compared for low frequency vibration measurements from 0 to 100 Hz. Different lengths of glass fiber reinforced composite samples with embedded polarimetric sensors are fabricated and compared for different vibration amplitudes and vibration frequencies. The influence of the vibration amplitude of the composite beams on the accuracy of vibration measurements using the two types of polarimetric sensors is investigated. At high amplitude vibrations the low strain sensitive PM-PCF polarimetric sensors offer a wider linear range and thus reproduce the vibration frequency and vibration amplitude accurately. However for high amplitude vibrations the high sensitivity and low dynamic strain range of Panda type fibers result in a multiple-peak intensity pattern within one vibration cycle which leads to inaccurate vibration frequency and vibration amplitude measurements. The experimental results show that the strain sensitivity of polarimetric sensors limits the vibration measurements to a certain range of vibration amplitudes. The vibration amplitude range over which the polarimetric sensors provide accurate information about the vibration frequency is experimentally investigated and the results are presented. Also, for a composite beam undergoing deflections in the ‘simply-simply supported’ configuration, a theoretical method to predict the allowable maximum measurable vibration amplitude for any type of polarimetric sensor, is derived in this paper. It is envisaged that the results from the studies will provide significant information, which can be used in composite material applications such as marine and aerospace for selecting an appropriate type and

  20. [Sexually transmitted diseases (STD) in adolescent girls].

    PubMed

    Henry-suchet, J

    1987-04-01

    Contraception has been a factor in lowering the age at 1st sexual intercourse, which is now about 15 years in France. At that age, changes of partners are frequent, placing sexually active adolescents at high risk of sexually transmitted diseases. 2 risks predominate, those of condyloma following infection with the papilloma virus which exposes patients to risk of dysplasia and cervical cancer, and that of salpingitis with its risk of sterility. Condyloma has become more frequent in adolescents in France in the past 5 years. A comparative study showed that the average age at diagnosis of intraepithelial epithelioma related to condyloma declined by 5 years between 1960-80. The average age of condyloma diagnosis is about 18 years. Condyloma in adolescents should be treated prudently. If resected too soon after the primary infection before formation of antibodies, there is a risk of propagating the virus. Adolescent condyloma represents the major indication for laser treatment after colposcopy and microhysteroscopy have been used to determine the exact limits of the lesion. Patients should be warned of the possibility of return and the need for regular monitoring. Partners should also be treated. Apart from barrier methods, no contraceptive methods are known to affect development of condyloma. Chronic and acute salpingitis are 2 different entities, but both can cause sterility. Of the 100,000 French women diagnosed with salpingitis each year, 1/2 are under 25 and 1/5 are under 20. Salpingitis multiplies the risk of extrauterine pregnancy by 6 and carries a 15% risk of sterility, which doubles with each new episode. 75% of cases of salpingitis are caused by sexually transmitted diseases, with chlamydia trachomatis responsible for about 1/2. The risk of salpingitis in oral contraceptive (OC) users is .2-.9 in relation to women not using contraception. The seriousness of salpingitis is significantly less for OC than for IUD users. On the other hand , various studies have

  1. Surface-Enhanced Impulsive Coherent Vibrational Spectroscopy

    PubMed Central

    Du, Juan; Harra, Juha; Virkki, Matti; Mäkelä, Jyrki M.; Leng, Yuxin; Kauranen, Martti; Kobayashi, Takayoshi

    2016-01-01

    Surface-enhanced Raman spectroscopy (SERS) has attracted a lot of attention in molecular sensing because of the remarkable ability of plasmonic metal nanostructures to enhance the weak Raman scattering process. On the other hand, coherent vibrational spectroscopy triggered by impulsive excitation using ultrafast laser pulses provides complete information about the temporal evolution of molecular vibrations, allowing dynamical processes in molecular systems to be followed in “real time”. Here, we combine these two concepts and demonstrate surface-enhanced impulsive vibrational spectroscopy. The vibrational modes of the ground and excited states of poly[2-methoxy-5-(2-ethylhexyloxy)−1,4-phenylenevinylene] (MEH-PPV), spin-coated on a substrate covered with monodisperse silver nanoparticles, are impulsively excited with a sub-10 fs pump pulse and characterized with a delayed broad-band probe pulse. The maximum enhancement in the spectrally and temporally resolved vibrational signatures averaged over the whole sample is about 4.6, while the real-time information about the instantaneous vibrational amplitude together with the initial vibrational phase is preserved. The phase is essential to determine the vibrational contributions from the ground and excited states. PMID:27812020

  2. Surface-Enhanced Impulsive Coherent Vibrational Spectroscopy

    NASA Astrophysics Data System (ADS)

    Du, Juan; Harra, Juha; Virkki, Matti; Mäkelä, Jyrki M.; Leng, Yuxin; Kauranen, Martti; Kobayashi, Takayoshi

    2016-11-01

    Surface-enhanced Raman spectroscopy (SERS) has attracted a lot of attention in molecular sensing because of the remarkable ability of plasmonic metal nanostructures to enhance the weak Raman scattering process. On the other hand, coherent vibrational spectroscopy triggered by impulsive excitation using ultrafast laser pulses provides complete information about the temporal evolution of molecular vibrations, allowing dynamical processes in molecular systems to be followed in “real time”. Here, we combine these two concepts and demonstrate surface-enhanced impulsive vibrational spectroscopy. The vibrational modes of the ground and excited states of poly[2-methoxy-5-(2-ethylhexyloxy)‑1,4-phenylenevinylene] (MEH-PPV), spin-coated on a substrate covered with monodisperse silver nanoparticles, are impulsively excited with a sub-10 fs pump pulse and characterized with a delayed broad-band probe pulse. The maximum enhancement in the spectrally and temporally resolved vibrational signatures averaged over the whole sample is about 4.6, while the real-time information about the instantaneous vibrational amplitude together with the initial vibrational phase is preserved. The phase is essential to determine the vibrational contributions from the ground and excited states.

  3. Turbojet blade vibration data acquisition design and feasibility testing

    NASA Technical Reports Server (NTRS)

    Frarey, J. L.; Petersen, N. J.; Hess, D. A.

    1978-01-01

    A turbojet blade vibration data acquisition system was designed to allow the measurement of blade vibration. The data acquisition system utilizing 96 microprocessors to gather data from optical probes, store, sort and transmit to the central computer is described. Areas of high technical risk were identified and a two-microprocessor system was breadboarded and tested to investigate these areas. Results show that the system was feasible and that low technical risk would be involved in proceeding with the complete system fabrication.

  4. Notification of transfusion transmitted infection.

    PubMed

    Choudhury, Lincoln P; Tetali, Shailaja

    2008-01-01

    The National Blood Policy of India, 2002, advocates the disclosure of results of transfusion transmitted infections (TTI) to blood donors. However, in the absence of well-defined notification processes, and in order to avoid serious consequences resulting from unguided disclosure, blood bank personnel discard blood that is TTI-positive. We report on a survey of 105 voluntary blood donors in Kerala. Only two out of three participants had filled the donor form in the last year. Only half were aware that the blood bank was supposed to inform them if they tested positive for TTI. Fifty-seven per cent of donors wanted to be informed every time they donated blood, irrespective of a positive or negative result.

  5. Transmitting plant viruses using whiteflies.

    PubMed

    Polston, Jane E; Capobianco, H

    2013-11-08

    Whiteflies, Hemiptera: Aleyrodidae, Bemisia tabaci, a complex of morphologically indistinquishable species(5), are vectors of many plant viruses. Several genera of these whitefly-transmitted plant viruses (Begomovirus, Carlavirus, Crinivirus, Ipomovirus, Torradovirus) include several hundred species of emerging and economically significant pathogens of important food and fiber crops (reviewed by(9,10,16)). These viruses do not replicate in their vector but nevertheless are moved readily from plant to plant by the adult whitefly by various means (reviewed by(2,6,7,9,10,11,17)). For most of these viruses whitefly feeding is required for acquisition and inoculation, while for others only probing is required. Many of these viruses are unable or cannot be easily transmitted by other means. Therefore maintenance of virus cultures, biological and molecular characterization (identification of host range and symptoms)(3,13), ecology(2,12), require that the viruses be transmitted to experimental hosts using the whitefly vector. In addition the development of new approaches to management, such as evaluation of new chemicals(14) or compounds(15), new cultural approaches(1,4,19), or the selection and development of resistant cultivars(7,8,18), requires the use of whiteflies for virus transmission. The use of whitefly transmission of plant viruses for the selection and development of resistant cultivars in breeding programs is particularly challenging(7). Effective selection and screening for resistance employs large numbers of plants and there is a need for 100% of the plants to be inoculated in order to find the few genotypes which possess resistance genes. These studies use very large numbers of viruliferous whiteflies, often several times per year. Whitefly maintenance described here can generate hundreds or thousands of adult whiteflies on plants each week, year round, without the contamination of other plant viruses. Plants free of both whiteflies and virus must be

  6. Transfusion-transmitted parasitic infections

    PubMed Central

    Singh, Gagandeep; Sehgal, Rakesh

    2010-01-01

    The transmission of parasitic organisms through transfusion is relatively rare. Of the major transfusion-transmitted diseases, malaria is a major cause of TTIP in tropical countries whereas babesiosis and Chagas’ disease pose the greatest threat to donors in the USA In both cases, this is due to the increased number of potentially infected donors. There are no reliable serologic tests available to screen donors for any of these organisms and the focus for prevention remains on adherence to donor screening guidelines that address travel history and previous infection with the etiologic agent. One goal is the development of tests that are able to screen for and identify donors potentially infectious for parasitic infections without causing the deferral of a large number of non-infectious donors or significantly increasing costs. Ideally, methods to inactivate the infectious organism will provide an element of added safety to the blood supply. PMID:20859503

  7. Transfusion-transmitted parasitic infections.

    PubMed

    Singh, Gagandeep; Sehgal, Rakesh

    2010-07-01

    The transmission of parasitic organisms through transfusion is relatively rare. Of the major transfusion-transmitted diseases, malaria is a major cause of TTIP in tropical countries whereas babesiosis and Chagas' disease pose the greatest threat to donors in the USA In both cases, this is due to the increased number of potentially infected donors. There are no reliable serologic tests available to screen donors for any of these organisms and the focus for prevention remains on adherence to donor screening guidelines that address travel history and previous infection with the etiologic agent. One goal is the development of tests that are able to screen for and identify donors potentially infectious for parasitic infections without causing the deferral of a large number of non-infectious donors or significantly increasing costs. Ideally, methods to inactivate the infectious organism will provide an element of added safety to the blood supply.

  8. Sexually transmitted infections in women.

    PubMed

    Van Der Pol, Barbara

    2014-01-01

    Sexually transmitted infections (STIs) are highly prevalent and cause a wide spectrum of disease. However, the majority of these infections may be unrecognized due to lack of overt signs or symptoms of infection. Asymptomatic infections remain significant as a result of the potential for long-term sequelae, predominately in women, and the risks of complications during pregnancy as well as mother-to-child transmission. Laboratory diagnostics play an important role in identifying infection and in public health efforts to reduce the prevalence of these diseases. Serologic diagnosis is appropriate for syphilis and, in some settings, for herpes infections. However, the organisms that cause discharge such as Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis and Mycoplasma genitalium are best diagnosed using molecular assays. Currently available molecular assays are suitable for use with non-invasively collected sample types, most notably vaginal swabs for women thus expanding the potential reach of STI control programs to include non-clinic based screening.

  9. Management of sexually transmitted diseases.

    PubMed

    1988-01-01

    Patients with sexually transmitted diseases (STDs) in developing countries are often untreated for long periods of time or receive ineffective treatment, producing complications that can lead to infertility, blindness, and even death. In addition, there is growing research evidence that people with bacterial or viral STDs are more likely to acquire--and perhaps transmit--the human immunodeficiency virus (HIV). STD control programs in developing countries must be reorganized to include: 1) good management of patients with STDs and their contacts, 2) case finding for syphilis in the antenatal population, 3) screenings and case findings for gonorrhea in high-risk groups, and 4) systematic prophylaxis for ophthalmia neonatorum in newborns. Since diagnosis before treatment is problematic in rural areas, the World Health Organization recommends simple treatment protocols based on the most common STD symptoms--urethral discharge; gynecological complaints such as vaginal discharge, low abdominal pain, or dysuria; genital ulceration; and inguinal bubo, a swelling of the lymph nodes in the groin. Other components of this approach include standardized treatment, contact tracing and treatment, health education targeted at high-risk groups, follow-up and case referral where necessary, and the collection of simple statistics on treatment efficacy and STD epidemiology. The incidence of STDs in developing countries is steadily increasing as a result of urbanization, increased numbers of young people, and delayed age at marriage. However, this situation can be combatted through application of treatment protocols, technological advances, improvements in the health care delivery system, and awareness on the part of policy makers of the seriousness of the STD problem.

  10. Wireless vibration sensor using frequency modulation technique

    NASA Astrophysics Data System (ADS)

    Kim, Minhyuck; Yoon, Hwan-Sik; Kim, Sehun; Kim, Joo-Hyung

    2012-04-01

    In recent years, wireless strain sensors have received attention as an efficient method to measure response of a structure in a remote location. Wireless sensors developed for remote measurement include RF wireless sensor modules and microstrip antenna-based sensors. In this paper, a simple wireless vibration sensor based on a piezoelectric sensor and the Frequency Modulation (FM) technique is developed for remote measurement of vibrating structures. The piezoelectric sensor can generate a voltage signal proportional to dynamic strain of the host structure. The voltage signal is then frequency modulated and transmitted wirelessly to a remote station by a simple FM transmitter circuit. Finally, the received signal is demodulated by a conventional FM radio circuit, and the vibration measurement data can be recovered. Since this type of wireless sensor employs a simple FM circuit, they do not require any wireless data transmission protocols allowing a low-cost wireless sensor in compact format. The proposed concept of the wireless vibration measurement is experimentally verified by measuring vibration of an aluminum cantilever beam. The proposed sensor could potentially be an efficient and cost effective method for measuring vibration of remote structures for dynamic testing or structural health monitoring.

  11. Noncontact Electromagnetic Vibration Source

    NASA Technical Reports Server (NTRS)

    Namkung, Min; Fulton, James P.; Wincheski, Buzz A.

    1994-01-01

    Metal aircraft skins scanned rapidly in vibration tests. Relatively simple combination of permanent magnets and electromagnet serves as noncontact vibration source for nondestructive testing of metal aircraft skins. In test, source excites vibrations, and vibration waveforms measured, then analyzed for changes in resonances signifying cracks and other flaws.

  12. Update on hand hygiene.

    PubMed

    Boyce, John M

    2013-05-01

    Recent developments related to hand hygiene include new test methods for evaluating hand hygiene products, improvements in alcohol-based hand rubs, novel methods of hand antisepsis, and new strategies and technologies for monitoring hand hygiene practices among health care personnel.

  13. Hand Dominance and Common Hand Conditions.

    PubMed

    Lutsky, Kevin; Kim, Nayoung; Medina, Juana; Maltenfort, Mitchell; Beredjiklian, Pedro K

    2016-05-01

    The goals of this study were to (1) assess how frequently patients present for evaluation of common hand disorders in relation to hand dominance and (2) evaluate the effect of hand dominance on function in patients with these conditions. The authors hypothesized that (1) the majority of patients who seek evaluation would have a condition that affects the dominant hand, and (2) disability scores would be worse if the dominant hand is involved. They retrospectively reviewed the records of consecutive patients who presented for treatment to their institution with unilateral symptoms of 5 common disorders of the hand: carpal tunnel syndrome (CTS), de Quervain's tenosynovitis (DEQ), lateral epicondylitis (LE), hand osteoarthritis (OA), and trigger finger (TF). The authors assessed the effect of diagnosis and hand dominance on Disabilities of the Arm, Shoulder and Hand (DASH) scores. The study group comprised 1029 patients (379 men and 650 women) with a mean age of 59.5 years. Ninety percent were right-hand dominant. The dominant and nondominant hands were affected with relatively equal frequency for CTS, DEQ, OA, and TF (range, 45%-53%). Patients with LE had a significantly higher incidence of dominant hand involvement. Men had lower DASH scores than women by an average of 7.9 points, and DASH scores were significantly but slightly higher for the overall group (3.2 points) when the dominant side was affected. Men with LE and women with TF and OA had significantly higher DASH scores when their dominant extremity was affected. Common hand disorders such as CTS, DEQ, OA, and TF affect the dominant and nondominant hands in roughly equivalent proportions, whereas LE is more common on the dominant side. Dominant hand involvement results in significantly worse DASH scores, although the magnitude of this is relatively small. Women have significantly higher DASH scores than men for the conditions evaluated. [Orthopedics. 2016; 39(3):e444-e448.].

  14. Flow-induced vibration

    SciTech Connect

    Blevins, R.D.

    1990-01-01

    This book reports on dimensional analysis; ideal fluid models; vortex-induced vibration; galloping and flutter; instability of tube and cylinder arrays; vibrations induced by oscillating flow; vibration induced by turbulence and sound; damping of structures; sound induced by vortex shedding; vibrations of a pipe containing a fluid flow; indices. It covers the analysis of the vibrations of structures exposed to fluid flows; explores applications for offshore platforms and piping; wind-induced vibration of buildings, bridges, and towers; and acoustic and mechanical vibration of heat exchangers, power lines, and process ducting.

  15. Vibration control in forge hammers. [by shock wave damping in foundation platform

    NASA Technical Reports Server (NTRS)

    Moise, F.; Lazarescu, C.

    1974-01-01

    Special measures are discussed for calculating, designing and executing a forge hammer foundation, so that the vibrations that occur during its working will not be transmitted to neighboring machinery, workrooms and offices. These vibrations are harmful to the workers near the forge hammer.

  16. Guideline Implementation: Hand Hygiene.

    PubMed

    Goldberg, Judith L

    2017-02-01

    Performing proper hand hygiene and surgical hand antisepsis is essential to reducing the rates of health care-associated infections, including surgical site infections. The updated AORN "Guideline for hand hygiene" provides guidance on hand hygiene and surgical hand antisepsis, the wearing of fingernail polish and artificial nails, proper skin care to prevent dermatitis, the wearing of jewelry, hand hygiene product selection, and quality assurance and performance improvement considerations. This article focuses on key points of the guideline to help perioperative personnel make informed decisions about hand hygiene and surgical hand antisepsis. The key points address the necessity of keeping fingernails and skin healthy, not wearing jewelry on the hands or wrists in the perioperative area, properly performing hand hygiene and surgical hand antisepsis, and involving patients and visitors in hand hygiene initiatives. Perioperative RNs should review the complete guideline for additional information and for guidance when writing and updating policies and procedures.

  17. Chapped hands (image)

    MedlinePlus

    Chapped hands can be sore and painful. Chapped hands may be soothed by the use of moisturizing lotions and the avoidance of excess exposure to water. If hands become badly chapped, hydrocortisone creams (available over the ...

  18. Hand splint - slideshow

    MedlinePlus

    ... this page: //medlineplus.gov/ency/presentations/100142.htm Hand splint - series—Indications To use the sharing features ... out of 4 Overview To begin making a hand dressing, place the injured hand around a cloth ...

  19. Sensitivity of Crustaceans to Substrate-Borne Vibration.

    PubMed

    Roberts, Louise; Breithaupt, Thomas

    2016-01-01

    There is increasing interest in the responsiveness of crustaceans to vibrations, especially in the context of marine developments where techniques such as pile driving create strong vibrations that are readily transmitted through the seabed. Experiments were undertaken under controlled conditions to investigate the sensitivity of unconditioned crustaceans to substrate-borne vibration. The subjects were exposed to a range of frequencies and amplitudes using the staircase method of presentation to determine the thresholds of response. Behavior varied according to the strength of the stimuli and included bursts of movement and rapid bouts of movement.

  20. USACE AIS Transmit Technical Support Summary Report

    DTIC Science & Technology

    2014-09-01

    USACE AIS Transmit Technical Support Summary Report Distribution Statement A: Approved for public release; distribution is unlimited...September 2014 Report No. CD-D-09-15 USACE AIS Transmit Technical Support Summary Report ii UNCLAS//Public | CG-926 RDC | I. Gonin et al. Public...States Coast Guard Research & Development Center 1 Chelsea Street New London, CT 06320 USACE AIS Transmit Technical Support Summary Report

  1. Vaginal microbiota and viral sexually transmitted diseases.

    PubMed

    Nardis, C; Mosca, L; Mastromarino, P

    2013-01-01

    Healthy vaginal microbiota is an important biological barrier to pathogenic microorganisms. When this predominantly Lactobacillus community is disrupted, decreased in abundance and replaced by different anaerobes, bacterial vaginosis (BV) may occur. BV is associated with prevalence and incidence of several sexually transmitted infections. This review provides background on BV, discusses the epidemiologic data to support a role of altered vaginal microbiota for acquisition of sexually transmitted diseases and analyzes mechanisms by which lactobacilli could counteract sexually transmitted viral infections.

  2. Vibrations in Glasses and Random Matrix Theory

    NASA Astrophysics Data System (ADS)

    Fabian, Jaroslav; Feldman, Joseph L.

    1998-03-01

    Vibrations in amorphous silicon are analyzed from the perspective of random matrix theory. We use the combination of the Wooten-Winer-Weaire random network and Stillinger-Weber interatomic potential to model the vibrational dynamics of amorphous silicon. By calculating the level-spacing distributions and spectral correlation functions for the vibrations of this model we find that the majority of the vibrations (diffusons--extended non-propagating modes) can be described in terms of random matrices (the corresponding level-spacing distribution corresponds to the Wigner surmise). On the other hand, localized modes, which in our model exist only at the highest frequencies, show no sign of spectral correlation and their level-spacing distribution is a Poisson one.

  3. [Contemporary hygienic regulation of industrial vibration: harmonizing national and foreign approaches].

    PubMed

    Prokopenko, L V; Kravchenko, O K; Kur'erov, N N

    2009-01-01

    The authors compared approaches to vibration safety regulations, presented by new Russian Federal governmental standards, international standards and rules from one hand, and by Russian Federal Sanitary Regulation documents from the other hand. Main directions to improve hygienic regulation of occupational vibration in new technical regulation system are determined.

  4. Methods to evaluate the microbicidal activities of hand-rub and hand-wash agents.

    PubMed

    Rotter, M; Sattar, S; Dharan, S; Allegranzi, B; Mathai, E; Pittet, D

    2009-11-01

    In vitro carrier tests, suspension tests, time-kill curves, and determinations of minimum inhibitory concentrations to evaluate the microbicidal activities of hand antiseptics provide only a preliminary indication of the antimicrobial spectrum and speed of action of a given formulation. Ex vivo testing with human or animal skin at human skin temperature and at contact times reflecting field conditions may give a better indication of a formulation's ability to tackle hand-transmitted pathogens. Field testing of hands for levels of skin microbiota before and after antisepsis may be easier to perform, but it is subject to many uncontrollable factors. Whereas randomised clinical trials may be the ultimate approach to assess the effectiveness of hand hygiene protocols and products in preventing microbial cross-transmission and, ultimately, infections, they can be prohibitively expensive, time-consuming, difficult to design, and therefore impractical. Hence, the primary emphasis should be on in vivo testing on human hands, using a well-designed protocol that closely simulates the recommended field use of the formulation, and possibly followed by clinical studies. The use of these method is the most likely to yield useful data on the potential of a formulation to interrupt the spread of pathogens transmitted by hands in healthcare settings. This review provides a critical assessment of the methods currently used to meet regulatory requirements for hand antiseptics in Europe and North America.

  5. Force reflecting hand controller for manipulator teleoperation

    NASA Technical Reports Server (NTRS)

    Bryfogle, Mark D.

    1991-01-01

    A force reflecting hand controller based upon a six degree of freedom fully parallel mechanism, often termed a Stewart Platform, has been designed, constructed, and tested as an integrated system with a slave robot manipulator test bed. A force reflecting hand controller comprises a kinesthetic device capable of transmitting position and orientation commands to a slave robot manipulator while simultaneously representing the environmental interaction forces of the slave manipulator back to the operator through actuators driving the hand controller mechanism. The Stewart Platform was chosen as a novel approach to improve force reflecting teleoperation because of its inherently high ratio of load generation capability to system mass content and the correspondingly high dynamic bandwidth. An additional novelty of the program was to implement closed loop force and torque control about the hand controller mechanism by equipping the handgrip with a six degree of freedom force and torque measuring cell. The mechanical, electrical, computer, and control systems are discussed and system tests are presented.

  6. Static hand gesture recognition from a video

    NASA Astrophysics Data System (ADS)

    Rokade, Rajeshree S.; Doye, Dharmpal

    2011-10-01

    A sign language (also signed language) is a language which, instead of acoustically conveyed sound patterns, uses visually transmitted sign patterns to convey meaning- "simultaneously combining hand shapes, orientation and movement of the hands". Sign languages commonly develop in deaf communities, which can include interpreters, friends and families of deaf people as well as people who are deaf or hard of hearing themselves. In this paper, we proposed a novel system for recognition of static hand gestures from a video, based on Kohonen neural network. We proposed algorithm to separate out key frames, which include correct gestures from a video sequence. We segment, hand images from complex and non uniform background. Features are extracted by applying Kohonen on key frames and recognition is done.

  7. Shaft instantaneous angular speed for blade vibration in rotating machine

    NASA Astrophysics Data System (ADS)

    Gubran, Ahmed A.; Sinha, Jyoti K.

    2014-02-01

    Reliable blade health monitoring (BHM) in rotating machines like steam turbines and gas turbines, is a topic of research since decades to reduce machine down time, maintenance costs and to maintain the overall safety. Transverse blade vibration is often transmitted to the shaft as torsional vibration. The shaft instantaneous angular speed (IAS) is nothing but the representing the shaft torsional vibration. Hence the shaft IAS has been extracted from the measured encoder data during machine run-up to understand the blade vibration and to explore the possibility of reliable assessment of blade health. A number of experiments on an experimental rig with a bladed disk were conducted with healthy but mistuned blades and with different faults simulation in the blades. The measured shaft torsional vibration shows a distinct difference between the healthy and the faulty blade conditions. Hence, the observations are useful for the BHM in future. The paper presents the experimental setup, simulation of blade faults, experiments conducted, observations and results.

  8. Metamaterial split ring resonator as a sensitive mechanical vibration sensor

    NASA Astrophysics Data System (ADS)

    Sikha Simon, K.; Chakyar, Sreedevi P.; Andrews, Jolly; Joseph V., P.

    2017-06-01

    This paper introduces a sensitive vibration sensor based on microwave metamaterial Split Ring Resonator (SRR) capable of detecting any ground vibration. The experimental setup consists of single Broad-side Coupled SRR (BCSRR) unit fixed on a cantilever capable of sensitive vibrations. It is arranged between transmitting and receiving probes of a microwave measurement system. The absorption level variations at the resonant frequency due to the displacement from the reference plane of SRR, which is a function of the strength of external mechanical vibration, is analyzed. This portable and cost effective sensor working on a single frequency is observed to be capable of detecting even very weak vibrations. This may find potential applications in the field of tamper-proofing, mining, quarrying and earthquake sensing.

  9. Sexually transmitted infections: challenges ahead.

    PubMed

    Unemo, Magnus; Bradshaw, Catriona S; Hocking, Jane S; de Vries, Henry J C; Francis, Suzanna C; Mabey, David; Marrazzo, Jeanne M; Sonder, Gerard J B; Schwebke, Jane R; Hoornenborg, Elske; Peeling, Rosanna W; Philip, Susan S; Low, Nicola; Fairley, Christopher K

    2017-08-01

    WHO estimated that nearly 1 million people become infected every day with any of four curable sexually transmitted infections (STIs): chlamydia, gonorrhoea, syphilis, and trichomoniasis. Despite their high global incidence, STIs remain a neglected area of research. In this Commission, we have prioritised five areas that represent particular challenges in STI treatment and control. Chlamydia remains the most commonly diagnosed bacterial STI in high-income countries despite widespread testing recommendations, sensitive and specific non-invasive testing techniques, and cheap effective therapy. We discuss the challenges for chlamydia control and evidence to support a shift from the current focus on infection-based screening to improved management of diagnosed cases and of chlamydial morbidity, such as pelvic inflammatory disease. The emergence and spread of antimicrobial resistance in Neisseria gonorrhoeae is globally recognised. We review current and potential future control and treatment strategies, with a focus on novel antimicrobials. Bacterial vaginosis is the most common vaginal disorder in women, but current treatments are associated with frequent recurrence. Recurrence after treatment might relate to evidence that suggests sexual transmission is integral to the pathogenesis of bacterial vaginosis, which has substantial implications for the development of effective management approaches. STIs disproportionately affect low-income and middle-income countries. We review strategies for case management, focusing on point-of-care tests that hold considerable potential for improving STI control. Lastly, STIs in men who have sex with men have increased since the late 1990s. We discuss the contribution of new biomedical HIV prevention strategies and risk compensation. Overall, this Commission aims to enhance the understanding of some of the key challenges facing the field of STIs, and outlines new approaches to improve the clinical management of STIs and public health

  10. Hand washing and surgical hand antisepsis.

    PubMed

    Pirie, Susan

    2010-05-01

    Hand hygiene has always been an important element of perioperative practice and is a topic that has gained even more importance in recent years for healthcare workers. In the mid 19th century Semmelweis first noted the link between hospital acquired diseases and hand hygiene (Semmelweis 1847, NATN 2000). More recently, it has been established that continuous effective hand hygiene can significantly decrease the transmission of microorganisms, thus reducing cross infection rates of many hospital acquired infections (Pratt et al 2007).

  11. On the control of vibrations using synchrophasing

    NASA Astrophysics Data System (ADS)

    Dench, M. R.; Brennan, M. J.; Ferguson, N. S.

    2013-09-01

    This paper describes the application of a technique, known as synchrophasing, to the control of machinery vibration. It is applicable to machinery installations, in which several synchronous machines, such as those driven by electrical motors, are fitted to an isolated common structure known as a machinery raft. To reduce the vibration transmitted to the host structure to which the machinery raft is attached, the phase of the electrical supply to the motors is adjusted so that the net transmitted force to the host structure is minimised. It is shown that while this is relatively simple for an installation consisting of two machines, it is more complicated for installations in which there are more than two machines, because of the interaction between the forces generated by each machine. The development of a synchrophasing scheme, which has been applied to propeller aircraft, and is known as Propeller Signature Theory (PST) is discussed. It is shown both theoretically and experimentally, that this is an efficient way of controlling the phase of multiple machines. It is also shown that synchrophasing is a worthwhile vibration control technique, which has the potential to suppress vibration transmitted to the host structure by up to 20 dB at certain frequencies. Although the principle of synchronisation has been demonstrated on a one-dimensional structure, it is believed that this captures the key features of the approach. However, it should be realised that the mode-shapes of a machinery raft may be more complex than that of a one-dimensional structure and this may need to be taken into account in a real application.

  12. Portable vibration exciter

    NASA Technical Reports Server (NTRS)

    Beecher, L. C.; Williams, F. T.

    1970-01-01

    Gas-driven vibration exciter produces a sinusoidal excitation function controllable in frequency and in amplitude. It allows direct vibration testing of components under normal loads, removing the possibility of component damage due to high static pressure.

  13. Control System Damps Vibrations

    NASA Technical Reports Server (NTRS)

    Kopf, E. H., Jr.; Brown, T. K.; Marsh, E. L.

    1983-01-01

    New control system damps vibrations in rotating equipment with help of phase-locked-loop techniques. Vibrational modes are controlled by applying suitable currents to drive motor. Control signals are derived from sensors mounted on equipment.

  14. Comparative studies of perceived vibration strength for commercial mobile phones.

    PubMed

    Lee, Heow Pueh; Lim, Siak Piang

    2014-05-01

    A mobile phone, also known as cell phone or hand phone, is among the most popular electrical devices used by people all over the world. The present study examines the vibration perception of mobile phones by co-relating the relevant design parameters such as excitation frequency, and size and mass of mobile phones to the vibration perception survey by volunteers. Five popular commercially available mobile phone models were tested. The main findings for the perception surveys were that higher vibration frequency and amplitude of the peak acceleration would result in stronger vibration perception of the mobile phones. A larger contact surface area with the palms and figures, higher peak acceleration and the associated larger peak inertia force may be the main factors for the relatively higher vibration perception. The future design for the vibration alert of the mobile phones is likely to follow this trend.

  15. Effects of Muscle Vibration on Multi-finger Interaction and Coordination

    PubMed Central

    Arpinar-Avsar, Pinar; Park, Jaebum; Zatsiorsky, Vladimir M.; Latash, Mark L.

    2013-01-01

    The purpose of this study was to investigate the effects of changes in the proprioceptive signals induced by muscle vibration on multi-finger interaction and coordination. We hypothesized that unintended force production by non-instructed fingers (enslaving) would increase with muscle vibration while synergy indices during steady-state force production would drop. The framework of the uncontrolled manifold hypothesis was used to quantify indices of multi-finger synergies stabilizing total force during steady-state force production and anticipatory changes in these indices (anticipatory synergy adjustments, ASAs) in preparation to a quick force pulse production with and without hand muscle vibration at 80 Hz. The dominant hands of twelve healthy right-handed subjects were tested under three conditions: no vibration, vibration of the palmar surface of the hand, and vibration of the forearm applied over the flexor muscles. There were no significant effects of vibration on maximal voluntary force. The magnitude of enslaving was larger during vibration of the hand compared to the other two conditions. During steady-state force production, strong synergies stabilizing total force were seen in all three conditions; however, indices of force-stabilizing synergies were lower during vibration of the hand. Prior to the force pulse initiation, the synergy index started to drop earlier and over a larger magnitude without vibration compared to either vibration condition. Effects of vibration on enslaving and synergy index may be due to diffuse reflex effects of the induced afferent activity on alpha-motoneuronal pools innervating the extrinsic flexor compartments. We conclude that multi-finger synergies are not based on signals from muscle receptors. The smaller synergy indices and ASAs may reflect supraspinal effects of the vibration-induced afferent activity, in particular its interactions with trans-thalamic loops. PMID:23736524

  16. Vibrational energy transport in the presence of intrasite vibrational energy redistribution.

    PubMed

    Schade, Marco; Hamm, Peter

    2009-07-28

    The mechanism of vibrational energy flow is studied in a regime where a diffusion equation is likely to break down, i.e., on length scales of a few chemical bonds and time scales of a few picoseconds. This situation occurs, for example, during photochemical reactions in protein environment. To that end, a toy model is introduced that on the one hand mimics the vibrational normal mode distribution of proteins, and on the other hand is small enough to numerically time propagate the system fully quantum mechanically. Comparing classical and quantum-mechanical results, the question is addressed to what extent the classical nature of the molecular dynamics simulations (which would be the only choice for the modeling of a real molecular system) affects the vibrational energy flow mechanism. Small differences are found which are due to the different ways classical and quantum mechanics distribute thermal energy over vibrational modes. In either case, a ballistic and a diffusive phase can be identified. For these small length and time scales, the latter is governed by intrasite vibrational energy redistribution, since vibrational energy does not necessarily thermalize completely within individual peptide units. Overall, the model suggests a picture that unifies many of the observations made recently in experiments.

  17. Studies of the Characteristics of a Densely-Coupled Array of Underwater Acoustic Transmitting Transducers

    NASA Astrophysics Data System (ADS)

    He, Zhengyao; Ma, Yuanliang

    2010-09-01

    The characteristics of a densely-coupled array of underwater acoustic transmitting transducers are studied. At first, the electro-acoustic characteristics such as the admittance, the resonant frequency and the transmitting voltage response, of a low frequency barrel-stave flextensional transducer and a densely-coupled compact array composed of three identical transducers uniformly distributed on a circle with spacing much less than half wavelength, are measured by experiments. Then, the radiation impedances of a single transducer and of transducers in the compact array are calculated by the boundary element model together with the finite element model. Based on the above results, the transducer's equivalent circuit model parameters are calculated in different cases, which include a single transducer in air and in water, and a densely-coupled array of three transducers parallel connected in water. The characteristics of the transducers and array are analyzed by the equivalent circuit model that was obtained. The research results show that when the transducers make up a densely-coupled compact array, the resonant frequency decreases and the transmitting bandwidth broadens. It is also shown that the mutual interactions among elements are significant for the compact array. The mutual radiation resistance between two transducers is close to the self-radiation resistance of the transducers. The vibration velocities of the transducers in the compact array are nearly 1/3 as those of a single transducer, and the radiation acoustic power and transmitting voltage response of the array are nearly the same as those of a single transducer, when the driving voltages of the array and single transducer are unchanged. Furthermore, the transmitting source level of the 3-element compact array is 8.9dB higher than that of the single transducer if the vibration velocities of the transducers in the array are the same as those of the single transducer. The proposed technique can be used

  18. Fingertip contact suppresses the destabilizing influence of leg muscle vibration

    NASA Technical Reports Server (NTRS)

    Lackner, J. R.; Rabin, E.; DiZio, P.

    2000-01-01

    Touch of the hand with a stationary surface at nonmechanically supportive force levels (<1 N) greatly attenuates postural sway during quiet stance. We predicted such haptic contact would also suppress the postural destabilization caused by vibrating the right peroneus brevis and longus muscles of subjects standing heel-to-toe with eyes closed. In experiment 1, ten subjects were tested under four conditions: no-vibration, no-touch; no-vibration, touch; vibration, no-touch; and vibration, touch. A hand-held physiotherapy vibrator (120 Hz) was applied approximately 5 cm above the malleolous to stimulate the peroneus longus and brevis tendons. Touch conditions involved contact of the right index finger with a laterally positioned surface (<1 N of force) at waist height. Vibration in the absence of finger contact greatly increased the mean sway amplitude of the center of pressure and of the head relative to the no-vibration, no-touch control condition (P < 0.001). The touch, no-vibration and touch-vibration conditions were not significantly different (P > 0.05) from each other and both had significantly less mean sway amplitude of head and of center of pressure than the other conditions (P < 0.01). In experiment 2, eight subjects stood heel-to-toe under touch and no-touch conditions involving 40-s duration trials of peroneus tendon vibration at different duty cycles: 1-, 2-, 3-, and 4-s ON and OFF periods. The vibrator was attached to the subject's leg and remotely activated. In the no-touch conditions, subjects showed periodic postural disruptions contingent on the duty cycle and mirror image rebounds with the offset of vibration. In the touch conditions, subjects were much less disrupted and showed compensations occurring within 500 ms of vibration onset and mirror image rebounds with vibration offset. Subjects were able to suppress almost completely the destabilizing influence of the vibration in the 3- and 4-s duty cycle trials. These experiments show that haptic

  19. Fingertip contact suppresses the destabilizing influence of leg muscle vibration

    NASA Technical Reports Server (NTRS)

    Lackner, J. R.; Rabin, E.; DiZio, P.

    2000-01-01

    Touch of the hand with a stationary surface at nonmechanically supportive force levels (<1 N) greatly attenuates postural sway during quiet stance. We predicted such haptic contact would also suppress the postural destabilization caused by vibrating the right peroneus brevis and longus muscles of subjects standing heel-to-toe with eyes closed. In experiment 1, ten subjects were tested under four conditions: no-vibration, no-touch; no-vibration, touch; vibration, no-touch; and vibration, touch. A hand-held physiotherapy vibrator (120 Hz) was applied approximately 5 cm above the malleolous to stimulate the peroneus longus and brevis tendons. Touch conditions involved contact of the right index finger with a laterally positioned surface (<1 N of force) at waist height. Vibration in the absence of finger contact greatly increased the mean sway amplitude of the center of pressure and of the head relative to the no-vibration, no-touch control condition (P < 0.001). The touch, no-vibration and touch-vibration conditions were not significantly different (P > 0.05) from each other and both had significantly less mean sway amplitude of head and of center of pressure than the other conditions (P < 0.01). In experiment 2, eight subjects stood heel-to-toe under touch and no-touch conditions involving 40-s duration trials of peroneus tendon vibration at different duty cycles: 1-, 2-, 3-, and 4-s ON and OFF periods. The vibrator was attached to the subject's leg and remotely activated. In the no-touch conditions, subjects showed periodic postural disruptions contingent on the duty cycle and mirror image rebounds with the offset of vibration. In the touch conditions, subjects were much less disrupted and showed compensations occurring within 500 ms of vibration onset and mirror image rebounds with vibration offset. Subjects were able to suppress almost completely the destabilizing influence of the vibration in the 3- and 4-s duty cycle trials. These experiments show that haptic

  20. Hand held phase-shifting diffraction moire interferometer

    DOEpatents

    Deason, Vance A.; Ward, Michael B.

    1994-01-01

    An interferometer in which a coherent beam of light is generated within a remote case and transmitted to a hand held unit tethered to said remote case, said hand held unit having optical elements for directing a pair of mutually coherent collimated laser beams at a diffraction grating. Data from the secondary or diffracted beams are then transmitted to a separate video and data acquisition system for recording and analysis for load induced deformation or for identification purposes. Means are also provided for shifting the phase of one incident beam relative to the other incident beam and being controlled from within said remote case.

  1. Hand held phase-shifting diffraction Moire interferometer

    DOEpatents

    Deason, V.A.; Ward, M.B.

    1994-09-20

    An interferometer is described in which a coherent beam of light is generated within a remote case and transmitted to a hand held unit tethered to said remote case, said hand held unit having optical elements for directing a pair of mutually coherent collimated laser beams at a diffraction grating. Data from the secondary or diffracted beams are then transmitted to a separate video and data acquisition system for recording and analysis for load induced deformation or for identification purposes. Means are also provided for shifting the phase of one incident beam relative to the other incident beam and being controlled from within said remote case. 4 figs.

  2. Hermetically sealed vibration damper

    NASA Technical Reports Server (NTRS)

    Wheatley, D. G.

    1969-01-01

    Simple fluidic vibration damper for installation at each pivotal mounting between gimbals isolates inertial measuring units from external vibration and other disruptive forces. Installation between each of the three gimbal axes can dampen vibration and shock in any direction while permitting free rotation of the gimbals.

  3. Tunable Passive Vibration Suppressor

    NASA Technical Reports Server (NTRS)

    Boechler, Nicholas (Inventor); Dillon, Robert Peter (Inventor); Daraio, Chiara (Inventor); Davis, Gregory L. (Inventor); Shapiro, Andrew A. (Inventor); Borgonia, John Paul C. (Inventor); Kahn, Daniel Louis (Inventor)

    2016-01-01

    An apparatus and method for vibration suppression using a granular particle chain. The granular particle chain is statically compressed and the end particles of the chain are attached to a payload and vibration source. The properties of the granular particles along with the amount of static compression are chosen to provide desired filtering of vibrations.

  4. Vibration-type particle separation device with piezoceramic vibrator

    NASA Astrophysics Data System (ADS)

    Ooe, Katsutoshi; Doi, Akihiro

    2008-12-01

    During hemanalysis, it is necessary to separate blood cells from whole blood. Many blood separation methods, for example, centrifugation and filtering, are in practical use. However, the use of these methods involves problems from the perspectives of processing speed and processing volume. We develop new types of blood separation devices that use piezo-ceramic vibrators. The first device uses a capillary. One end of the capillary is fixed to the device frame, and the other is fixed to a piezo-ceramic vibrator. The vibrator transmits bending waves to the capillary. This device can process only a small amount of solution; therefore, it is not suitable for hemanalysis. In order to solve this problem, we developed a second device; this device has a pair of thin glass plates with a small gap as a substitute for the capillary used in the first device. These devices are based on the fact that particles heavier than water move toward transverse velocity antinodes while those lighter than water move toward velocity nodes. In this report, we demonstrate the highspeed separation of silica microbeads and 50-vol% glycerol water by using these devices. The first device can separate the abovementioned solution within 3 min while the second can separate it within 1 min. Both devices are driven by a rectangular wave of 15 to 20 Vpp. Furthermore, it has been confirmed that red blood cells are separated from diluted whole blood using the first device within approximately 1 min. These devices have transparency, so they can compose as the analysis system with the chemical analyzer easily.

  5. C-130J Human Vibration

    DTIC Science & Technology

    2005-08-01

    Organisation DSTO-TR-1756 ABSTRACT Human exposure to whole - body vibration (WBV) has been associated with a variety of changes in health...1.2.1 Whole - body Vibration (WBV) ................................................................... 3 1.2.2 Local vibration ...amplitude transmissibility VDV vibration dose value VWF vibration -induced white finger WBV whole body vibration DSTO-TR-1756 1 1. Introduction

  6. Method and apparatus for transmitting data

    NASA Technical Reports Server (NTRS)

    Schroeder, George L. (Inventor); Couch, Francis O. (Inventor); Saenguraiporn, Chamna (Inventor)

    1990-01-01

    A method and apparatus for transmitting a byte-organized serial data stream from a transmitting station to a receiving station that may employ byte boundaries different than the transmitting station. The technique includes sending N different data streams from the remote terminal, where N is the number of different framing alignments that may be imposed on the unframed data stream by the network. The different data streams are chosen so that one will be framed by the network as the intended data stream regardless of which framing alignment is actually imposed.

  7. Parasitic diseases in humans transmitted by vectors.

    PubMed

    Cholewiński, Marcin; Derda, Monika; Hadaś, Edward

    2015-01-01

    Despite the considerable progress of medicine, parasitic diseases still pose a great threat to human health and life. Among parasitic diseases, those transmitted by vectors, mainly arthropods, play a particular role. These diseases occur most frequently in the poorest countries and affect a vast part of the human population. They include malaria, babesiosis, trypanosomiasis, leishmaniasis and filariasis. This study presents those vector-transmitted diseases that are responsible for the greatest incidence and mortality of people on a global scale. Attention is focused primarily on diseases transmitted by mosquitoes, flies, Hemiptera and ticks.

  8. No Telescoping Effect with Dual Tendon Vibration

    PubMed Central

    Bellan, Valeria; Wallwork, Sarah B.; Stanton, Tasha R.; Reverberi, Carlo; Gallace, Alberto; Moseley, G. Lorimer

    2016-01-01

    The tendon vibration illusion has been extensively used to manipulate the perceived position of one’s own body part. However, findings from previous research do not seem conclusive sregarding the perceptual effect of the concurrent stimulation of both agonist and antagonist tendons over one joint. On the basis of recent data, it has been suggested that this paired stimulation generates an inconsistent signal about the limb position, which leads to a perceived shrinkage of the limb. However, this interesting effect has never been replicated. The aim of the present study was to clarify the effect of a simultaneous and equal vibration of the biceps and triceps tendons on the perceived location of the hand. Experiment 1 replicated and extended the previous findings. We compared a dual tendon stimulation condition with single tendon stimulation conditions and with a control condition (no vibration) on both ‘upward-downward’ and ‘towards-away from the elbow’ planes. Our results show a mislocalisation towards the elbow of the position of the vibrated arm during dual vibration, in line with previous results; however, this did not clarify whether the effect was due to arm representation contraction (i.e., a ‘telescoping’ effect). Therefore, in Experiment 2 we investigated explicitly and implicitly the perceived arm length during the same conditions. Our results clearly suggest that in all the vibration conditions there was a mislocalisation of the entire arm (including the elbow), but no evidence of a contraction of the perceived arm length. PMID:27305112

  9. No Telescoping Effect with Dual Tendon Vibration.

    PubMed

    Bellan, Valeria; Wallwork, Sarah B; Stanton, Tasha R; Reverberi, Carlo; Gallace, Alberto; Moseley, G Lorimer

    2016-01-01

    The tendon vibration illusion has been extensively used to manipulate the perceived position of one's own body part. However, findings from previous research do not seem conclusive sregarding the perceptual effect of the concurrent stimulation of both agonist and antagonist tendons over one joint. On the basis of recent data, it has been suggested that this paired stimulation generates an inconsistent signal about the limb position, which leads to a perceived shrinkage of the limb. However, this interesting effect has never been replicated. The aim of the present study was to clarify the effect of a simultaneous and equal vibration of the biceps and triceps tendons on the perceived location of the hand. Experiment 1 replicated and extended the previous findings. We compared a dual tendon stimulation condition with single tendon stimulation conditions and with a control condition (no vibration) on both 'upward-downward' and 'towards-away from the elbow' planes. Our results show a mislocalisation towards the elbow of the position of the vibrated arm during dual vibration, in line with previous results; however, this did not clarify whether the effect was due to arm representation contraction (i.e., a 'telescoping' effect). Therefore, in Experiment 2 we investigated explicitly and implicitly the perceived arm length during the same conditions. Our results clearly suggest that in all the vibration conditions there was a mislocalisation of the entire arm (including the elbow), but no evidence of a contraction of the perceived arm length.

  10. Hand washing practices in a college town environment.

    PubMed

    Borchgrevink, Carl P; Cha, JaeMin; Kim, SeungHyun

    2013-04-01

    Many people do not wash their hands when the behavior in which they engage would warrant it. Most research of hand washing practices to date has taken place in high-traffic environments such as airports and public attraction venues. These studies have established a persistent shortcoming and a gender difference in hand washing compliance. Using field observations of 3,749 people in a college town environment, the research described in this article replicates and extends earlier work while identifying potential environmental and demographic predictors of hand washing compliance. Additionally, the authors' research suggests that proper hand washing practices, as recommended by the Centers for Disease Control and Prevention, are not being practiced. Finally, the authors' research raises a question as to the accuracy of earlier measurements of "proper" hand washing practices, suggesting that compliance rates are inflated. The results can help increase hand washing rates for the general public and thus decrease the risk of transmitting disease.

  11. Effects of vibration measurement error on remote sensing image restoration

    NASA Astrophysics Data System (ADS)

    Sun, Xuan; Wei, Zhang; Zhi, Xiyang

    2016-10-01

    Satellite vibrations would lead to image motion blur. Since the vibration isolators cannot fully suppress the influence of vibrations, image restoration methods are usually adopted, and the vibration characteristics of imaging system are usually required as algorithm inputs for better restoration results, making the vibration measurement error strongly connected to the final outcome. If the measurement error surpass a certain range, the restoration may not be implemented successfully. Therefore it is important to test the applicable scope of restoration algorithms and control the vibrations within the range, on the other hand, if the algorithm is robust, then the requirements for both vibration isolator and vibration detector can be lowered and thus less financial cost is needed. In this paper, vibration-induced degradation is first analyzed, based on which the effects of measurement error on image restoration are further analyzed. The vibration-induced degradation is simulated using high resolution satellite images and then the applicable working condition of typical restoration algorithms are tested with simulation experiments accordingly. The research carried out in this paper provides a valuable reference for future satellite design which plan to implement restoration algorithms.

  12. Nonlinear Vibrational Spectroscopy: a Method to Study Vibrational Self-Trapping

    NASA Astrophysics Data System (ADS)

    Hamm, Peter; Edler, Julian

    We review the capability of nonlinear vibrational spectroscopy to study vibrational self-trapping in hydrogen-bonded molecular crystals. For that purpose, the two relevant coupling mechanisms, excitonic coupling and nonlinear exciton-phonon coupling, are first introduced separately using appropriately chosen molecular systems as examples. Both coupling mechanisms are subsequently combined, yielding vibrational selftrapping. The experiments unambiguously prove that both the N-H and the C=O band of crystalline acetanilide (ACN), a model system for proteins, show vibrational self-trapping. The C=O band is self-trapped only at low enough temperature, while thermally induced disorder destroys the mechanism at room temperature. The binding energy of the N-H band, on the other hand, is considerably larger and self-trapping survives thermal fluctuations even at room temperature.

  13. Hand fracture - aftercare

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000552.htm Hand fracture - aftercare To use the sharing features on ... need to be repaired with surgery. Types of Hand Fractures Your fracture may be in one of ...

  14. Sexually Transmitted Diseases: Teens at Risk.

    ERIC Educational Resources Information Center

    Mascola, Laurene

    1987-01-01

    Parents of preteens need to be aware of the rapidly increasing incidence of sexually transmitted diseases among teenagers and to begin talking to their preteens to help prevent or modify risky sexual experimentation during middle adolescence. (MT)

  15. Diagnostic Testing for Sexually Transmitted Infections

    MedlinePlus

    ... Head Neck & Nervous System Heart Infections Learning Disabilities Obesity Orthopedic Prevention Sexually Transmitted Skin Tobacco Treatments Injuries & ... Severely ill patients may be hospitalized and given antibiotics intravenously. Genital Warts/Human Papillomavirus (HPV) Physical examination, ...

  16. Sexually transmitted infections, pregnancy, and breastfeeding

    MedlinePlus

    ... Genital herpes fact sheet Genital warts fact sheet Gonorrhea fact sheet HIV/AIDS Human papillomavirus (HPV) Pap ... sexually transmitted diseases, or STDs. STIs include chlamydia, gonorrhea, trichomoniasis, genital herpes, genital warts, HIV, and syphilis. ...

  17. Clinical update in sexually transmitted diseases-2014.

    PubMed

    Fanfair, Robyn Neblett; Workowski, Kimberly A

    2014-02-01

    Sexually transmitted diseases (STDs) and their associated syndromes are extremely common in clinical practice. Early diagnosis, appropriate treatment, and partner management are important to ensure sexual, physical, and reproductive health in our patients.

  18. Sexually Transmitted Diseases: Teens at Risk.

    ERIC Educational Resources Information Center

    Mascola, Laurene

    1987-01-01

    Parents of preteens need to be aware of the rapidly increasing incidence of sexually transmitted diseases among teenagers and to begin talking to their preteens to help prevent or modify risky sexual experimentation during middle adolescence. (MT)

  19. Center of percussion of hand-held implements

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2004-05-01

    The center of percussion is commonly regarded as a sweet spot when referring to a baseball bat or a tennis racquet because it is assumed that there will be no sudden motion of the handle with respect to the hand if the corresponding axis of rotation passes through the hand. A problem with this interpretation is that the hand extends over a finite length of the handle and exerts an opposing reaction force on the handle. The hand also changes the total mass and moment of inertia of the system, while the arm restricts free motion of the hand. Experimental results are presented showing that the axis of rotation passes through the hand or the wrist for all the usual impact points on a hand-held implement. As a result, the impact point that feels best is usually the node of the fundamental vibration mode, not the center of percussion.

  20. Vibration Penalty Estimates for Indoor Annoyance Caused by Sonic Boom

    NASA Technical Reports Server (NTRS)

    Rathsam, Jonathan; Klos, Jacob

    2016-01-01

    Commercial supersonic flight is currently forbidden over land because sonic booms have historically caused unacceptable annoyance levels in overflown communities. NASA is providing data and expertise to noise regulators as they consider relaxing the ban for future quiet supersonic aircraft. One key objective is a predictive model for indoor annoyance based on factors such as noise and indoor vibration levels. The current study quantified the increment in indoor sonic boom annoyance when sonic booms can be felt directly through structural vibrations in addition to being heard. A shaker mounted below each chair in the sonic boom simulator emulated vibrations transmitting through the structure to that chair. The vibration amplitudes were determined from numeric models of a large range of residential structures excited by the same sonic boom waveforms used in the experiment. The analysis yielded vibration penalties, which are the increments in sound level needed to increase annoyance as much as the vibration does. For sonic booms at acoustic levels from 75 to 84 dB Perceived Level, vibration signals with lower amplitudes (+1 sigma) yielded penalties from 0 to 5 dB, and vibration signals with higher amplitudes (+3 sigma) yielded penalties from 6 to 10 dB.

  1. Infection after hand surgery.

    PubMed

    Eberlin, Kyle R; Ring, David

    2015-05-01

    Postoperative infections are uncommon after hand surgery. Infection can delay recovery and contribute to scarring and stiffness. Measures intended to reduce the risk of infection after hand surgery include hand washing, skin preparation, sterile technique, and prophylactic antibiotics. The role of prophylactic antibiotics for small, clean, elective hand surgery procedures lasting less than 2 hours is debated. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Structural hysteresis model of transmitting mechanical systems

    NASA Astrophysics Data System (ADS)

    Ruderman, M.; Bertram, T.

    2015-02-01

    We present a structural hysteresis model which describes the dynamic behavior of transmitting mechanical systems with a hysteretic spring and damped bedstop element, both connected in series. From the application point view this approach can be used for predicting the transmitted mechanical force based only on the known kinematic excitation. Using the case study of an elastic gear transmission we show and identify a hysteresis response which multivariate behavior depends on an internal state of the bedstop motion.

  3. Compact Telerobot Hand

    NASA Technical Reports Server (NTRS)

    Rosheim, Mark; Trechsel, Hans

    1993-01-01

    Anthropomorphic telerobotic hand contains actuators, joints, sensors, and complex wiring harnesses. Glove protects interior components of hand from dirt and damage. Imitates motions of human fingers and wrist in lifelike and dexterous way. Incorporates pitch/yaw joints in wrist and head knuckles. Hand modular; so fingers removable, interchangeable units. Feature simplifies servicing and maintenance, which must be done frequently in such complex mechanism.

  4. Robotic hand and fingers

    DOEpatents

    Salisbury, Curt Michael; Dullea, Kevin J.

    2017-06-06

    Technologies pertaining to a robotic hand are described herein. The robotic hand includes one or more fingers releasably attached to a robotic hand frame. The fingers can abduct and adduct as well as flex and tense. The fingers are releasably attached to the frame by magnets that allow for the fingers to detach from the frame when excess force is applied to the fingers.

  5. Hand x-ray

    MedlinePlus

    X-ray - hand ... A hand x-ray is taken in a hospital radiology department or your health care provider's office by an ... technician. You will be asked to place your hand on the x-ray table, and keep it ...

  6. Eggshell Cutter Using Ultrasonic Vibration

    NASA Astrophysics Data System (ADS)

    Miura, Hikaru

    2003-05-01

    An eggshell cutting apparatus which utilizes ultrasonic vibration was developed, replacing the conventional apparatus which uses an air cutter, to cut eggshells at the blunt end of eggs. Two ultrasonic vibration sources were used: one with longitudinal vibration only and the other with torsional vibration plus longitudinal vibration. Eggshell cutting experiments using these vibration sources were conducted. The eggshell cutting time sharply decreased with increasing longitudinal vibration amplitude as well as increasing input power. When the source with torsional vibration plus longitudinal vibration was used and the amplitude of longitudinal vibration was 12 μm or less, the torsional vibration was effective for cutting eggshells. Furthermore, at the same input power, the eggshell cutting time by the source with longitudinal vibration only was shorter than that by the source with torsional vibration plus longitudinal vibration. When an egg was cut using the apparatus, there was essentially no cutting noise and the cut surface was smooth.

  7. Removable hand hold

    NASA Technical Reports Server (NTRS)

    Corrigan, Robert D. (Inventor); Hauer, Robert L. (Inventor)

    1992-01-01

    A hand hold utilizes joining mechanisms which comprises two different mounting brackets that are permanently fastened to a supporting structure. A slide plate is disposed at one end of the hand rail or hand hold which mates with one of the mounting brackets. A securing member is disposed at the opposite end of the hand rail/hand hold which connects with the other mounting bracket by means of a locking device. The slide plate has a central tapered tongue with two matching slots disposed on each side thereof.

  8. Vibration Transmission through Bearings with Application to Gearboxes

    NASA Technical Reports Server (NTRS)

    Fleming, David P.

    2007-01-01

    Cabin noise has become a major concern to manufacturers and users of helicopters. Gear noise is the largest part of this unwanted sound. The crucial noise path is generally considered to be from the gears through the gear-supporting shafts and bearings into the gearbox case, and from there either through the gearbox mounts or the surrounding air to the helicopter cabin. If the noise, that is, the gear and shaft vibration, can be prevented from traveling through the gearbox bearings, then the noise cannot make its way into the helicopter cabin. Thus the vibration-transmitting properties of bearings are of paramount importance. This paper surveys the literature concerning evaluation of properties for the types of bearings used in helicopter gearboxes. A simple model is proposed to evaluate vibration transmission, using measured or calculated bearing stiffness and damping. Less-commonly used types of gearbox bearings (e.g., fluid film) are evaluated for their potential in reducing vibration transmission.

  9. Design of a candidate vibrational signal for mating disruption against the glassy-winged sharpshooter, Homalodisca Vitripennis

    USDA-ARS?s Scientific Manuscript database

    The glassy-winged sharpshooter (GWSS), Homalodisca vitripennis, is an important pest of grapevines due to its ability to transmit Xylella fastidiosa, the causal agent of Pierce’s disease. GWSS mating communication is based on vibrational signals; therefore, vibrational mating disruption could be an ...

  10. Vibration welding system with thin film sensor

    DOEpatents

    Cai, Wayne W; Abell, Jeffrey A; Li, Xiaochun; Choi, Hongseok; Zhao, Jingzhou

    2014-03-18

    A vibration welding system includes an anvil, a welding horn, a thin film sensor, and a process controller. The anvil and horn include working surfaces that contact a work piece during the welding process. The sensor measures a control value at the working surface. The measured control value is transmitted to the controller, which controls the system in part using the measured control value. The thin film sensor may include a plurality of thermopiles and thermocouples which collectively measure temperature and heat flux at the working surface. A method includes providing a welder device with a slot adjacent to a working surface of the welder device, inserting the thin film sensor into the slot, and using the sensor to measure a control value at the working surface. A process controller then controls the vibration welding system in part using the measured control value.

  11. Thermal Vibrational Convection

    NASA Astrophysics Data System (ADS)

    Gershuni, G. Z.; Lyubimov, D. V.

    1998-08-01

    Recent increasing awareness of the ways in which vibrational effects can affect low-gravity experiments have renewed interest in the study of thermal vibrational convection across a wide range of fields. For example, in applications where vibrational effects are used to provide active control of heat and mass transfer, such as in heat exchangers, stirrers, mineral separators and crystal growth, a sound understanding of the fundamental theory is required. In Thermal Vibrational Convection, the authors present the theory of vibrational effects caused by a static gravity field, and of fluid flows which appear under vibration in fluid-filled cavities. The first part of the book discusses fluid-filled cavities where the fluid motion only appears in the presence of temperature non-uniformities, while the second considers those situations where the vibrational effects are caused by a non-uniform field. Throughout, the authors concentrate on consideration of high frequency vibrations, where averaging methods can be successfully applied in the study of the phenomena. Written by two of the pioneers in this field, Thermal Vibrational Convection will be of great interest to scientists and engineers working in the many areas that are concerned with vibration, and its effect on heat and mass transfer. These include hydrodynamics, hydro-mechanics, low gravity physics and mechanics, and geophysics. The rigorous approach adopted in presenting the theory of this fascinating and highly topical area will facilitate a greater understanding of the phenomena involved, and will lead to the development of more and better-designed experiments.

  12. Adaptive control for payload launch vibration isolation

    NASA Astrophysics Data System (ADS)

    Jarosh, Julian R.; Agnes, Gregory S.; Karahalis, Gregory G.

    2001-07-01

    The Department of Defense has identified launch vibration isolation as a major research interest. Reducing the loads a satellite experiences during launch will greatly enhance the reliability and lifetime and decrease the payload structural mass. DoD space programs stand to benefit significantly from advances in vibration isolation technology. This study explores potential hybrid vibration isolation using adaptive control with a passive isolator. Lyapunov analysis is used to develop the structural adaptive control scheme. Simulink and Matlab simulations investigate these control methodologies on a lumped mass dynamic model of a satellite and its representative launch vehicle. The results are compared to Proportional-Integral-Derivative (PID) control and skyhook damper active control methods. The results of the modeling indicate adaptive control achieves up to a 90 percent reduction in loads on the payload when compared to the conventional active control methods. The adaptive controller compensated for the loads being transmitted to the payload from the rest of the launch vehicle. The current adaptive controller was not able to effectively control the motion of a vibrating subcomponent within the payload or the subcomponent's effect on the overall payload itself.

  13. Emitted vibration measurement device and method

    NASA Technical Reports Server (NTRS)

    Gisler, G. L. (Inventor)

    1986-01-01

    This invention is directed to a method and apparatus for measuring emitted vibrational forces produced by a reaction wheel assembly due to imbalances, misalignment, bearing defects and the like. The apparatus includes a low mass carriage supported on a large mass base. The carriage is in the form of an octagonal frame having an opening which is adapted for receiving the reaction wheel assembly supported thereon by means of a mounting ring. The carriage is supported on the base by means of air bearings which support the carriage in a generally frictionless manner when supplied with compressed air from a source. A plurality of carriage brackets and a plurality of base blocks provided for physical coupling of the base and carriage. The sensing axes of the load cells are arranged generally parallel to the base and connected between the base and carriage such that all of the vibrational forces emitted by the reaction wheel assembly are effectively transmitted through the sensing axes of the load cells. In this manner, a highly reliable and accurate measurment of the vibrational forces of the reaction wheel assembly can be had. The output signals from the load cells are subjected to a dynamical analyzer which analyzes and identifies the rotor and spin bearing components which are causing the vibrational forces.

  14. Transmission of vibration through gloves: effects of contact area.

    PubMed

    Md Rezali, Khairil Anas; Griffin, Michael J

    2017-01-01

    For three samples of material (12.5, 25.0 and 37.5 mm diameter) from each of three gloves, the dynamic stiffnesses and the vibration transmissibilities of the materials (to both the palm of the hand and the thenar eminence) were measured at frequencies from 10 to 300 Hz. Additional measurements showed the apparent masses of the hand at the palm and the thenar eminence were independent of contact area at frequencies less than about 40 Hz, but increased with increasing area at higher frequencies. The stiffness and damping of the glove materials increased with increasing area. These changes caused material transmissibilities to the hand to increase with increasing area. It is concluded that the size of the area of contact has a large influence on the transmission of vibration through a glove to the hand. The area of contact should be well-defined and controlled when evaluating the transmission of vibration through gloves. Practitioner Summary: The transmission of vibration through gloves depends on both the dynamic stiffness of glove material and the dynamic response of the hand. Both of these depend on the size of the contact area between a glove material and the hand, which should be taken into account when assessing glove transmissibility.

  15. [Raynaud's phenomenon in occupational vibration exposure].

    PubMed

    Letzel, S; Muttray, A

    2013-03-01

    A 34-year-old female stonemason was referred for expert opinion. The question at issue was, whether she suffered from vibration-induced white finger disease. She was exposed to high-frequency hand-arm vibrations for many years. She reported white finger attacks at the long fingers, which were associated with cold weather. Until this point, physical findings were normal. The cold water provocation test showed a slight delay of the rewarming for the long fingers of the right hand. The nailfold capillary microscopy was normal. The slight Raynaud's phenomenon was recognized as an occupational disease with a diagnosis of vibration-induced white finger disease. About three years later, the symptoms of the Raynaud's phenomenon had deteriorated, although the patient had finished working with vibrating tools. The cold water provocation test confirmed the deterioration. At this time, the patient had inflamed swellings of some joints caused by rheumatoid arthritis. The differential diagnosis of a Raynaud's phenomenon should include occupational causes. Occupational history is diagnostically indicative. If an occupational disease is assumed, a report must be filed. With respect to German social law, the deterioration of the Raynaud's phenomenon was caused by the rheumatoid arthritis, which is regarded as independent from the job. © Georg Thieme Verlag KG Stuttgart · New York.

  16. Avoiding the Health Hazard of People from Construction Vehicles: A Strategy for Controlling the Vibration of a Wheel Loader

    PubMed Central

    Chi, Feng; Zhou, Jun; Zhang, Qi; Wang, Yong; Huang, Panling

    2017-01-01

    The vibration control of a construction vehicle must be carried out in order to meet the aims of sustainable environmental development and to avoid the potential human health hazards. In this paper, based on market feedback, the driver seat vibration of a type of wheel loader in the left and right direction, is found to be significant over a certain speed range. In order to find abnormal vibration components, the order tracking technique (OTT) and transmission path analysis (TPA) were used to analyze the vibration sources of the wheel loader. Through this analysis, it can be seen that the abnormal vibration comes from the interaction between the tire tread and the road, and this is because the vibration was amplified by the cab mount, which was eventually transmitted to the cab seat. Finally, the seat vibration amplitudes were decreased by up to 50.8%, after implementing the vibration reduction strategy. PMID:28282849

  17. Avoiding the Health Hazard of People from Construction Vehicles: A Strategy for Controlling the Vibration of a Wheel Loader.

    PubMed

    Chi, Feng; Zhou, Jun; Zhang, Qi; Wang, Yong; Huang, Panling

    2017-03-08

    The vibration control of a construction vehicle must be carried out in order to meet the aims of sustainable environmental development and to avoid the potential human health hazards. In this paper, based on market feedback, the driver seat vibration of a type of wheel loader in the left and right direction, is found to be significant over a certain speed range. In order to find abnormal vibration components, the order tracking technique (OTT) and transmission path analysis (TPA) were used to analyze the vibration sources of the wheel loader. Through this analysis, it can be seen that the abnormal vibration comes from the interaction between the tire tread and the road, and this is because the vibration was amplified by the cab mount, which was eventually transmitted to the cab seat. Finally, the seat vibration amplitudes were decreased by up to 50.8%, after implementing the vibration reduction strategy.

  18. Assessing the Likelihood of Hand-to-Hand Cross-Transmission of Bacteria: An Experimental Study.

    PubMed

    Bellissimo-Rodrigues, Fernando; Pires, Daniela; Soule, Hervé; Gayet-Ageron, Angèle; Pittet, Didier

    2017-02-22

    BACKGROUND Although the hands of healthcare workers (HCWs) are implicated in most episodes of healthcare-associated infections, the correlation between hand contamination and the likelihood of cross-transmission remains unknown. METHODS We conducted a laboratory-based study involving pairs of HCWs. The hands of a HCW (transmitter) were contaminated with Escherichia coli ATCC 10536 before holding hands with another HCW (host) for 1 minute. Meanwhile, the unheld hand of the transmitter was sampled. Afterward, the host's held hand was also sampled. Each experiment consisted of 4 trials with increasing concentrations of E. coli (103-106 colony-forming units [cfu]/mL). The primary outcome was the likelihood of transmission of at least 1 cfu from transmitter to host. We used a mixed logistic regression model with a random effect on the subject to assess the association between transmission and bacterial count on the transmitter's hands. RESULTS In total, 6 HCWs performed 30 experiments and 120 trials. The bacterial counts recovered from host hands were directly associated with the bacterial counts on transmitter hands (P1 and ≤3 log10 cfu compared to ≤1 log10. When transmitter contamination was <1 log10 cfu, no cross-transmission was detected. CONCLUSION There is a direct relationship between the bacterial burden on HCWs hands and the likelihood of cross-transmission. Under the described conditions, at least 1 log10 cfu must be present on HCW hands to be potentially transmitted. Further studies are needed at the low contamination range. Infect Control Hosp Epidemiol 2017;1-6.

  19. Vibration study of the APS magnet support assemblies

    SciTech Connect

    Wambsganss, M.W.; Jendrzejczyk, J.A.; Chen, S.S.

    1990-11-01

    Stability of the positron closed orbit is a requirement for successful operation of the Advanced Photon Source. The fact that vibration of the storage ring quadrupole magnets can lead to distortion of the positron closed orbit and to potentially unacceptable beam emittance growth provides the motivation for the subject studies. Low frequency vibrations can be controlled with steering magnets using feedback systems, provided the vibration amplitudes are within the dynamic range of the controllers. High frequency vibration amplitudes, on the other hand, are out of the range of the controller and, therefore must be limited to ensure the emittance growth will not exceed a prescribed value. Vibration criteria were developed based on the requirement that emittance growth be limited to 10 percent. Recognizing that the quadrupole magnets have the most significant effect, three different scenarios were considered: vibration of a single quadrupole within the storage ring, random vibration of all the quadrupoles in the ring, and the hypothetical case of a plane wave sweeping across the site and the quadrupoles following the motion of the plane wave. The maximum allowable peak vibration amplitudes corresponding to these three vibration scenarios are given. The criteria associated with the passage of a plane wave is dependent on wavelength, or, alternatively, on frequency given the wave speed. The wave speed used is that measured as a part of the geotechnical investigation at the APS site.

  20. Circular Polarization of Transmitted Light by Sapphirinidae Copepods

    PubMed Central

    Baar, Yuval; Rosen, Joseph; Shashar, Nadav

    2014-01-01

    Circularly polarized light, rare in the animal kingdom, has thus far been documented in only a handful of animals. Using a rotating circular polarization (CP) analyzer we detected CP in linearly polarized light transmitted through epipelagic free living Sapphirina metallina copepods. Both left and right handedness of CP was detected, generated from specific organs of the animal's body, especially on the dorsal cephalosome and prosome. Such CP transmittance may be generated by phase retardance either in the muscle fibers or in the multilayer membrane structure found underneath the cuticle. Although the role, if any, played by circularly polarized light in Sapphirinidae has yet to be clarified, in other animals it was suggested to take part in mate choice, species recognition, and other forms of communication. Highlights Planktonic Sapphirinidae copepods were found to circularly polarize the light passing through them. Circular polarization may be created by unique, multilayered features of the membrane structure found under their cuticle or by organized muscle fibers. PMID:24465916

  1. Non-contacting Hand Image Certification System Using Morphological Analysis

    NASA Astrophysics Data System (ADS)

    Moritani, Motoki; Saitoh, Fumihiko

    This paper proposes a non-contacting certification system by using morphological analysis of hand images to access security control. The non-contacting hand image certification system is more effective than contacting system where psychological resistance and conformability are required. The morphology is applied to get useful individual characteristic even if the pose of a hand is changed. First, a hand image is captured using the transmitted lighting. Next, the wrist area is removed from the hand area. The pattern spectrum that represents the form of the hand area is measured by the morphological analysis, and the spectrum is normalized to the invariant pattern to the scale change. Finally, the certification of an individual is performed by the neural network. The experimental results show that the sufficient accuracy to certificate individuals was obtained by the proposed system.

  2. Substrate-borne vibrations induce behavioral responses in the leaf-dwelling cerambycid, Paraglenea fortunei.

    PubMed

    Tsubaki, Remi; Hosoda, Naoe; Kitajima, Hiroshi; Takanashi, Takuma

    2014-12-01

    Many insects utilize substrate-borne vibrations as a source of information for recognizing mates or predators. Among various substrates, plant leaves are commonly used for transmitting and receiving vibrational information. However, little is known about the utilization of vibrations by leaf-dwelling insects, especially coleopteran beetles. We conducted two experiments to examine the response of the leaf-dwelling cerambycid beetle, Paraglenea fortunei, to substrate-borne vibrations. We recorded and analyzed vibrations of host plant leaves from four different sources: wind (0.5 m/s), a beetle during landing, a walking beetle, and a beetle walking in the wind (0.5 m/s). We then measured the behavioral thresholds, the lowest amplitudes that induce behavioral responses, from beetles walking and resting on horizontal and vertical substrates with pulsed vibrations ranging from 20 Hz to 1 kHz. The vibrational characteristics of biotic and abiotic stimuli clearly differed. Beetle-generated vibrations (landing, walking, and walking in the wind) were broadly high in the low-frequency components above ∼30 Hz, while wind-generated vibrations showed a dominant peak at ∼30 Hz and a steep decrease thereafter. Among four situations, beetles walking on horizontal substrates showed lowest thresholds to vibrations of 75-500 Hz, which are characteristic of beetle-generated vibrations. Given that P. fortunei beetles are found on horizontal leaf surfaces of the host plant, vibrations transmitted though horizontal substrates may induce a strong freeze response in walking beetles to detect conspecifics or heterospecifics. Our findings provide evidence that leaf-dwelling beetles can discriminate among biotic and abiotic factors via differences in vibrational characteristics.

  3. Topographic analysis of the skull vibration-induced nystagmus test with piezoelectric accelerometers and force sensors.

    PubMed

    Dumas, Georges; Lion, Alexis; Perrin, Philippe; Ouedraogo, Evariste; Schmerber, Sébastien

    2016-03-23

    Vibration-induced nystagmus is elicited by skull or posterior cervical muscle stimulations in patients with vestibular diseases. Skull vibrations delivered by the skull vibration-induced nystagmus test are known to stimulate the inner ear structures directly. This study aimed to measure the vibration transfer at different cranium locations and posterior cervical regions to contribute toward stimulus topographic optimization (experiment 1) and to determine the force applied on the skull with a hand-held vibrator to study the test reproducibility and provide recommendations for good clinical practices (experiment 2). In experiment 1, a 100 Hz hand-held vibrator was applied on the skull (vertex, mastoids) and posterior cervical muscles in 11 healthy participants. Vibration transfer was measured by piezoelectric sensors. In experiment 2, the vibrator was applied 30 times by two experimenters with dominant and nondominant hands on a mannequin equipped to measure the force. Experiment 1 showed that after unilateral mastoid vibratory stimulation, the signal transfer was higher when recorded on the contralateral mastoid than on the vertex or posterior cervical muscles (P<0.001). No difference was observed between the different vibratory locations when vibration transfer was measured on vertex and posterior cervical muscles. Experiment 2 showed that the force applied to the mannequin varied according to the experimenters and the handedness, higher forces being observed with the most experienced experimenter and with the dominant hand (10.3 ± 1.0 and 7.8 ± 2.9 N, respectively). The variation ranged from 9.8 to 29.4% within the same experimenter. Bone transcranial vibration transfer is more efficient from one mastoid to the other mastoid than other anatomical sites. The mastoid is therefore the optimal site for skull vibration-induced nystagmus test in patients with unilateral vestibular lesions and enables a stronger stimulation of the healthy side. In clinical practice

  4. a Comparison of Biodynamic Models of the Human HAND-ARM System for Applications to Hand-Held Power Tools

    NASA Astrophysics Data System (ADS)

    RAKHEJA, S.; WU, J. Z.; DONG, R. G.; SCHOPPER, A. W.; BOILEAU, P.-É.

    2002-01-01

    The biodynamic response characteristics of various mechanical models of the human hand and arm system, reported in the literature, are evaluated in terms of their driving-point mechanical impedance modulus and phase responses. The suitability of the reported models for applications in realizing a mechanical simulator and assessment of vibration behavior of hand-held power tools is examined using three different criteria. These include the ability of the model to characterize the driving-point mechanical impedance of the human hand-arm system within the range of idealized values presented in ISO-10068 (1998); the magnitude of model deflection under a static feed force; and the vibration properties of the human hand and arm evaluated in terms of natural frequencies and damping ratios. From the relative evaluations of 12 different models, it is concluded that a vast majority of these models cannot be applied for the development of a mechanical hand-arm simulator or the assessment of dynamic behavior of the coupled hand-tool system. The higher order models, with three and four degrees of freedom, in general, yield impedance characteristics within the range of idealized values, but exhibit excessive static deflections. Moreover, these models involve very light masses (in the 1·2-4·8 g range), and exhibit either one or two vibration modes at frequencies below 10 Hz. The majority of the lower order models yield reasonable magnitudes of static deflections but relatively poor agreement with idealized values of driving-point mechanical impedance.

  5. Adaptive vibration energy harvesting

    NASA Astrophysics Data System (ADS)

    Behrens, Sam; Ward, John; Davidson, Josh

    2007-04-01

    By scavenging energy from their local environment, portable electronic devices such as mobile phones, radios and wireless sensors can achieve greater run-times with potentially lower weight. Vibration energy harvesting is one such approach where energy from parasitic vibrations can be converted into electrical energy, through the use of piezoelectric and electromagnetic transducers. Parasitic vibrations come from a range of sources such as wind, seismic forces and traffic. Existing approaches to vibration energy harvesting typically utilise a rectifier circuit, which is tuned to the resonant frequency of the harvesting structure and the dominant frequency of vibration. We have developed a novel approach to vibration energy harvesting, including adaption to non-periodic vibrations so as to extract the maximum amount of vibration energy available. Experimental results of an experimental apparatus using off-the-shelf transducer (i.e. speaker coil) show mechanical vibration to electrical energy conversion efficiencies of 27 - 34%. However, simulations of a more electro-mechanical efficient and lightly damped transducer show conversion efficiencies in excess of 80%.

  6. [Sexually transmitted diseases--an update].

    PubMed

    Davidovitch, Nadav; Shohat, Tami; Dan, Michael

    2005-04-01

    Sexually transmitted infections represent an worldwide challenge for the public health. According to WHO estimates, approximately 330 million people are infected annually by curable sexually transmitted infections (AIDS excluded). and their incidence has been increasing, particularly in high-risk populations. Like in other developed countries, the occurrence of venereal diseases in Israel has been increasing recently. In addition, a sharp rise has been observed in the resistance rate of gonococci to fluoroquinolones. The purpose of the present review is to update the information on the epidemiology, diagnosis, therapy and prevention of sexually transmitted diseases (STDs) in Israel. In response to the reemergence of these diseases in Israel, it was decided in the Ministry of Health to open for the first time ever STD clinics in the two cities with the highest disease burden, namely Tel Aviv and Haifa. These clinics are staffed with a multidisciplinary group of specialists, including gynecologists, dermatologists, epidemiologists, nurses and social workers.

  7. Acoustic and Vibration Environment for Crew Launch Vehicle Mobile Launcher

    NASA Technical Reports Server (NTRS)

    Vu, Bruce T.

    2007-01-01

    A launch-induced acoustic environment represents a dynamic load on the exposed facilities and ground support equipment (GSE) in the form of random pressures fluctuating around the ambient atmospheric pressure. In response to these fluctuating pressures, structural vibrations are generated and transmitted throughout the structure and to the equipment items supported by the structure. Certain equipment items are also excited by the direct acoustic input as well as by the vibration transmitted through the supporting structure. This paper presents the predicted acoustic and vibration environments induced by the launch of the Crew Launch Vehicle (CLV) from Launch Complex (LC) 39. The predicted acoustic environment depicted in this paper was calculated by scaling the statistically processed measured data available from Saturn V launches to the anticipated environment of the CLV launch. The scaling was accomplished by using the 5-segment Solid Rocket Booster (SRB) engine parameters. Derivation of vibration environment for various Mobile Launcher (ML) structures throughout the base and tower was accomplished by scaling the Saturn V vibration environment.

  8. The alien hand syndrome

    PubMed Central

    Panikkath, Deepa; Mojumder, Deb; Nugent, Kenneth

    2014-01-01

    A 77-year-old woman presented with the complaint of observing her left hand moving without her knowledge while watching television. Her left hand stroked her face and hair as if somebody was controlling it. These movements lasted only half an hour but on recovery, she had left hemiparesis. Alien hand syndrome as the presentation of cardioembolic stroke is extremely rare but can be terrifying to patients. PMID:24982566

  9. Hand and Power Tools

    DTIC Science & Technology

    1998-01-01

    Hand and Power Tools U.S. Department of Labor Occupational Safety and Health Administration OSHA 3080 1998 (Revised) Report Documentation Page Report...Date 00001998 Report Type N/A Dates Covered (from... to) - Title and Subtitle Hand and Power Tools Contract Number Grant Number Program...basic safety procedures and safeguards associated with hand and portable power tools . Material in this booklet is based on the standards of the

  10. Improved "Smart" Robot Hand

    NASA Technical Reports Server (NTRS)

    Szakaly, Zoltan F.; Vigh, Zoltan; Bejczy, Antal; Ohm, Timothy

    1990-01-01

    Improved version of developmental "smart" robot hand equipped with bidirectional, wide-band optical-fiber link for transmission of digitized strain-gauge force- and torque-sensor signals from hand and for transmission of command signals to motor drive unit on hand. Collection of sensor data speeded hundredfold. Higher data-collection speed makes possible to perform advanced processing of sensor data in host processor.

  11. Dextrous robot hands

    NASA Technical Reports Server (NTRS)

    Venkataraman, Subramanian T. (Editor); Iberall, Thea (Editor)

    1990-01-01

    Recent studies of human hand function and their implications for the design of robot hands are discussed in reviews and reports. Topics addressed include human grasp choice and robotic grasp analysis, opposition space and human prehension, coordination in normal and prosthetic reaching, and intelligent exploration by the human hand. Consideration is given to a task-oriented dextrous manipulation architecture, the control architecture for the Belgrade/USC hand, the analysis of multifingered grasping and manipulation, and tactile sensing for shape interpretation. Diagrams, graphs, and photographs are provided.

  12. [Optimizing surgical hand disinfection].

    PubMed

    Kampf, G; Kramer, A; Rotter, M; Widmer, A

    2006-08-01

    For more than 110 years hands of surgeons have been treated before a surgical procedure in order to reduce the bacterial density. The kind and duration of treatment, however, has changed significantly over time. Recent scientific evidence suggests a few changes with the aim to optimize both the efficacy and the dermal tolerance. Aim of this article is the presentation and discussion of new insights in surgical hand disinfection. A hand wash should be performed before the first disinfection of a day, ideally at least 10 min before the beginning of the disinfection as it has been shown that a 1 min hand wash significantly increases skin hydration for up to 10 min. The application time may be as short as 1.5 min depending on the type of hand rub. Hands and forearms should be kept wet with the hand rub for the recommended application time in any case. A specific rub-in procedure according to EN 12791 has been found to be suitable in order to avoid untreated skin areas. The alcohol-based hand rub should have a proven excellent dermal tolerance in order to ensure appropriate compliance. Considering these elements in clinical practice can have a significant impact to optimize the high quality of surgical hand disinfection for prevention of surgical site infections.

  13. Coordination of Hand Shape

    PubMed Central

    Pesyna, Colin; Pundi, Krishna; Flanders, Martha

    2011-01-01

    The neural control of hand movement involves coordination of the sensory, motor and memory systems. Recent studies have documented the motor coordinates for hand shape, but less is known about the corresponding patterns of somatosensory activity. To initiate this line of investigation, the present study characterized the sense of hand shape by evaluating the influence of differences in the amount of grasping or twisting force, and differences in forearm orientation. Human subjects were asked to use the left hand to report the perceived shape of the right hand. In Experiment 1, six commonly grasped items were arranged on the table in front of the subject: bottle, doorknob, egg, notebook, carton, pan. With eyes closed, subjects used the right hand to lightly touch, forcefully support or imagine holding each object, while 15 joint angles were measured in each hand with a pair of wired gloves. The forces introduced by supporting or twisting did not influence the perceptual report of hand shape, but for most objects, the report was distorted in a consistent manner by differences in forearm orientation. Subjects appeared to adjust the intrinsic joint angles of the left hand, as well as the left wrist posture, so as to maintain the imagined object in its proper spatial orientation. In a second experiment, this result was largely replicated with unfamiliar objects. Thus somatosensory and motor information appear to be coordinated in an object-based, spatial coordinate system, sensitive to orientation relative to gravitational forces, but invariant to grasp forcefulness. PMID:21389230

  14. Hand Hygiene: An Update.

    PubMed

    Bolon, Maureen K

    2016-09-01

    The medical field has long recognized the importance of hand hygiene in preventing health care-associated infections, yet studies indicate that this important task is performed only 40% of the time. Health care workers cite several barriers to optimal performance of hand hygiene, but the time required to perform this task is foremost among them. Introduction of alcohol-based hand rubs, bundled interventions, and incorporation of technologies designed to monitor and promote hand hygiene all represent promising advances in this field. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Dextrous robot hands

    NASA Technical Reports Server (NTRS)

    Venkataraman, Subramanian T. (Editor); Iberall, Thea (Editor)

    1990-01-01

    Recent studies of human hand function and their implications for the design of robot hands are discussed in reviews and reports. Topics addressed include human grasp choice and robotic grasp analysis, opposition space and human prehension, coordination in normal and prosthetic reaching, and intelligent exploration by the human hand. Consideration is given to a task-oriented dextrous manipulation architecture, the control architecture for the Belgrade/USC hand, the analysis of multifingered grasping and manipulation, and tactile sensing for shape interpretation. Diagrams, graphs, and photographs are provided.

  16. Osteomyelitis of the hand.

    PubMed

    Pinder, R; Barlow, G

    2016-05-01

    Osteomyelitis of the hand is uncommon, but if not adequately and promptly treated the detrimental effects on hand function can be devastating. The majority of literature on osteomyelitis relates to the lower limb, but the principles of management are applicable to the hand, with good surgical debridement and culture-guided antimicrobial therapy. For osteomyelitis in general, antibiotic therapy of 4-6 weeks' duration (intravenous and/or oral) is typically recommended. In the hand, length and mode of antibiotic administration are still under study. V. © The Author(s) 2015.

  17. Chlamydial Infection: A Common Sexually Transmitted Disease

    PubMed Central

    Sorbie, Janet

    1982-01-01

    Chlamydia trachomatis infection is more prevalent than gonorrhea and causes a similar clinical picture. It is the prime cause of non-gonococcal urethritis in men and pelvic inflammatory disease in women. Its sequelae in women are ectopic pregnancy and infertility. It can be transmitted from an infected mother to her newborn child, leading to inclusion conjunctivitis and pneumonia. Tetracycline and erythromycin are effective in eradicating chlamydial infections, but the penicillins are not. Screening of high risk groups and special diagnostic facilities would help control this common sexually transmitted disease. PMID:20469385

  18. Sexually transmitted diseases in Sabah and Sarawak.

    PubMed Central

    Catterall, R D

    1981-01-01

    Despite being part of one of the few remaining primitive areas of the world, both Sabah and Sarawak are provided with adequate, though simple, urban and rural general medical services. At present no reliable data on the incidence of sexually transmitted diseases in these areas have been collected and no organised treatment services are available. Gonorrhoea appears to be the commonest notifiable infectious disease in Sarawak, and beta-lactamase-producing strains have been isolated. Because of the rapidly expanding economy and the encouragement of the tourist trade, sexually transmitted disease is likely to prove an increasing problem, for which a specialised service for diagnosis and treatment is badly needed. PMID:6895709

  19. Sexually transmitted diseases and the mobility explosion

    PubMed Central

    Catterall, R. D.

    1975-01-01

    The very great increase in the tourist industry during the past 20 years is described. This has occurred at a time when there has been an unprecedented rise in the incidence of sexually transmitted diseases. Evidence is presented that there is a relationship between the number of tourists and other travellers and the prevalence of sexually transmitted diseases. Case histories from three different categories of tourist are described and the impact of tourism on the spread of disease is stressed. It is suggested that health authorities throughout the world should give further consideration to plans to meet the challenge of the mobility explosion. PMID:1243165

  20. Updating the management of sexually transmitted infections.

    PubMed

    Ooi, Catriona; Lewis, David

    2015-12-01

    The control of sexually transmitted infections relies on case-finding and treatment of sexual contacts to prevent further transmission. Screening for infections should be tailored to the demographic and sexual risk of the individual. For most sexually transmitted infections, screening is performed on self-collected, non-invasive samples using highly sensitive molecular assays. These are quick and inexpensive. Shorter courses of antivirals for genital herpes are now recommended. New chemoprophylactic strategies for preventing HIV transmission have emerged, including treatment to prevent transmission and the use of antiretrovirals for pre-exposure prophylaxis.

  1. Sexually transmitted infections in polygamous mating systems

    PubMed Central

    Ashby, Ben; Gupta, Sunetra

    2013-01-01

    Sexually transmitted infections (STIs) are often associated with chronic diseases and can have severe impacts on host reproductive success. For airborne or socially transmitted pathogens, patterns of contact by which the infection spreads tend to be dispersed and each contact may be of very short duration. By contrast, the transmission pathways for STIs are usually characterized by repeated contacts with a small subset of the population. Here we review how heterogeneity in sexual contact patterns can influence epidemiological dynamics, and present a simple model of polygyny/polyandry to illustrate the impact of biased mating systems on disease incidence and pathogen virulence. PMID:23339239

  2. Helicobacter pylori: a sexually transmitted bacterium?

    PubMed Central

    2014-01-01

    Introduction Oral sex (fellatio) is a very common sexual activity. H. pylori is mainly a gastric organism, but studies have reported that infected individuals may permanently or transiently carry H. pylori in their mouth and saliva. Material and methods A Pubmed search was conducted using the words infection, oral sex and urethritis. Results The existing studies support the hypothesis that H. pylori could be a causative agent of non–gonococcal urethritis. Conclusions It is possible that H. pylori may be transmitted via the act of fellatio in the urethra. Further research is required to explore the role of H. pylori in sexually transmitted urethritis. PMID:25667764

  3. Photoelectronic vibrometer with polarized light. [for torsional vibration measurements

    NASA Technical Reports Server (NTRS)

    Kremmer, I.

    1974-01-01

    A seismic torsiometer is described which is based on the reception by a photosensitive transducer of a light flux modulated by a relative rotation of the optical axes of two polaroids. The torsional vibrations of the polaroid fixed to the shaft are transmitted to the other polaroid (which at the same time is the seismic mass of the apparatus) by means of elastic lamellas. The device can work as accelerometer, vibrometer or frequency meter, depending on the value of the ratio between the proper oscillation frequency of the seismic system and the measured vibration frequency.

  4. Piezoelectric nonlinear vibration focusing on the second-harmonic vibration mode.

    PubMed

    Ozaki, Ryohei; Liu, Yaoyang; Hosaka, Hiroshi; Morita, Takeshi

    2017-04-22

    Resonant piezoelectric devices are driven under high power condition. In such condition, a nonlinear piezoelectric vibration becomes apparent and this nonlinearity should be taken into account in the design procedure using the finite elemental method (FEM). The purpose of this study is to introduce the nonlinear parameter to the FEM and to establish the method for measuring the nonlinear parameter through evaluating a nonlinear model for a piezoelectric vibration. In a previous study about the nonlinear piezoelectric vibration, the third term was mainly focused on because the third mode vibration affects the fundamental vibration in the case of a simple bar-type transducer. On the other hand, we considered the second nonlinear parameter of the compliance to the piezoelectric constitutive equation. We observed that this parameter affects the vibration amplitude with each position and the velocity at the tip of the transducer with a double frequency at resonant. It was confirmed that two measured nonlinear parameters based on these two relationships were almost same. From these values, we concluded that the proposed model is reasonable. Copyright © 2017. Published by Elsevier B.V.

  5. String vibration dampers do not reduce racket frame vibration transfer to the forearm.

    PubMed

    Li, F X; Fewtrell, D; Jenkins, M

    2004-01-01

    In this study, we examined the effect of string vibration damping devices on reducing racket frame vibration transfer to the forearm. Twenty participants volunteered to hold a tennis racket stationary in a forehand and backhand stroking position while tennis balls were fired at 20 m x s(-1) towards two impact locations, the node of vibration and the dead spot. A three-way analysis of variance with repeated measures on damping condition, impact location and stroke condition was performed on the data. The resonant frequency of the hand-held racket was found to be approximately 120 Hz. No significant differences in amplitude of vibration at the resonant frequency were found for the wrist or the elbow when damped and non-damped impacts were compared. Impacts at the dead spot produced greater amplitudes of vibration (P < 0.01) but no interaction between impact location and string dampers was evident. The string dampers had no effect on the grip force used or the muscle electrical activity in the forearm after impact. In conclusion, we found that string dampers do not reduce the amount of racket frame vibration received at the forearm. We suggest that string dampers remain a popular accessory among tennis players because of their acoustic effects and psychological support rather than any mechanical advantage.

  6. [Hand surgery training].

    PubMed

    Moutet, F; Haloua, J P

    2003-10-01

    Training of the hand surgeon HAND SURGEON A CONCEPT: The hand surgeon is supposed to be in charge of all the hand lesions regarding, skeleton, muscles, tendons, nerves and vessels. He has to be able to insure reparation and coverage of all of them. So he is involved in all the structures, which insure integrity and function of the hand. PURPOSE AND WAYS OF TRAINING: To obtain the asked ability, the hand surgeon training has to be global and sustained by two underlying surgical specialities: orthopedic surgery and plastic and reconstructive surgery. From 2000 after many years of dealings, a Right to the Title in Hand Surgery was born. This Right to the Title wants to be the formal recognition of the specific training of the hand surgeon. For the well-recognized ancient hand surgeons they need to be confirmed by one's peers. Now a day the hand surgeon has to satisfy to this specific training: Passed the complete training and exam of the Orthopedic or Plastic surgery board. Spent at least 6 months as resident in the other underlying specialty. Passed a microsurgery examination. Passed one of the four national Hand Surgery diplomas (DIU/Inter-Universitary Diploma). The examinations have been harmonized. A common formation is delivered regarding hand surgery, the way of examination is the same and the formation is 2 years long. The final exam is presented in front of board of examiners where a teacher of one of the other three national diplomas is present. Spent at least 2 years in a formative hand surgery unit, listed by the French College of Hand Surgeons, as senior surgeon. Those requirements are heavy to assume and need a heavy personal involvement. That seems to be necessary to have an ability level as high as possible. Emergency surgery practice is absolutely necessary in this training. All the 17 university formative hand surgery units listed by the French College of Hand Surgeons are members of the FESUM (European Federation of the Emergency Hand Units

  7. Characteristics of spaceborne cooler passive vibration isolator by using a compressed shape memory alloy mesh washer

    NASA Astrophysics Data System (ADS)

    Oh, Hyun-Ung; Kwon, Seong-Cheol; Youn, Se-Hyun

    2015-01-01

    Cryogenic coolers produce undesirable micro-vibrations during on-orbit operation, which may seriously affect the image quality of high-resolution observation satellites. Micro-vibrations can be easily isolated by mounting the cooler on a vibration isolator with low stiffness to attenuate the vibration transmitted to the satellite structure. However, the structural safety of a cooler supported by an isolator with low stiffness cannot be guaranteed under the much more severe vibration condition of a launch environment. In this study, to guarantee vibration isolation performance in a launch environment while effectively isolating the micro-vibrations from the cooler on-orbit, a new type of passive vibration isolation system by using a compressed shape memory alloy mesh washer was proposed and investigated. The basic characteristics of the isolator were measured in static and free vibration tests of the isolator, and a simple equivalent model of the isolator was proposed. The effectiveness of the isolator design in a launch environment was demonstrated through sine vibration, random vibration, and shock tests.

  8. Treating the Rheumatoid Hand

    PubMed Central

    Hastings, D. E.; Welsh, R. P.

    1978-01-01

    Deformities in the rheumatoid hand will vary according to whether the joints or the tendons are involved. Frequently both will be involved and several different deformities will be present in the same hand. However, a logical approach to examination and treatment, as outlined in this article, will simplify decision making and ensure prompt, appropriate treatment. PMID:21304805

  9. [Passover hand injuries].

    PubMed

    Ashur, H; Mushayov, R

    1994-04-01

    Almost every year just before Passover there is increased exposure to hand trauma in matzah bakeries. In the past 5 years we treated 11 cases of hand trauma incurred during matzah baking. The typical injuries were amputations at different levels, crush injuries and burns. We present a case seen last Passover and suggest preventive methods to eliminate these accidents in the future.

  10. A Helping Hand.

    ERIC Educational Resources Information Center

    Renner, Jason M.

    2000-01-01

    Discusses how designing a hand washing-friendly environment can help to reduce the spread of germs in school restrooms. Use of electronic faucets, surface risk management, traffic flow, and user- friendly hand washing systems that are convenient and maximally hygienic are examined. (GR)

  11. A Helping Hand.

    ERIC Educational Resources Information Center

    Renner, Jason M.

    2000-01-01

    Discusses how designing a hand washing-friendly environment can help to reduce the spread of germs in school restrooms. Use of electronic faucets, surface risk management, traffic flow, and user- friendly hand washing systems that are convenient and maximally hygienic are examined. (GR)

  12. Vibrational Schroedinger Cats

    NASA Technical Reports Server (NTRS)

    Kis, Z.; Janszky, J.; Vinogradov, An. V.; Kobayashi, T.

    1996-01-01

    The optical Schroedinger cat states are simple realizations of quantum states having nonclassical features. It is shown that vibrational analogues of such states can be realized in an experiment of double pulse excitation of vibrionic transitions. To track the evolution of the vibrational wave packet we derive a non-unitary time evolution operator so that calculations are made in a quasi Heisenberg picture.

  13. [Vibration on agricultural tractors].

    PubMed

    Peretti, Alessandro; Delvecchio, Simone; Bonomini, Francesco; di Bisceglie, Anita Pasqua; Colosio, Claudio

    2013-01-01

    In the article, details related to the diffusion of agricultural tractors in Italy are given and considerations about the effects of vibration on operators, the sources of vibration and suggestions to reduce them are presented. The acceleration values observed in Italy amongst 244 tractors and levels of worker exposure are shown by means of histograms. The relevant data variability is discussed.

  14. Force limited vibration testing

    NASA Technical Reports Server (NTRS)

    Scharton, Terry D.

    1991-01-01

    A new method of conducting lab vibration tests of spacecraft equipment was developed to more closely simulate the vibration environment experienced when the spacecraft is launched on a rocket. The improved tests are tailored to identify equipment design and workmanship problems without inducing artificial failures that would not have occurred at launch. These new, less destructive types of vibration tests are essential to JPL's protoflight test approach in which lab testing is conducted using the flight equipment, often one of a kind, to save time and money. In conventional vibration tests, only the input vibratory motion is specified; the feedback, or reaction force, between the test item and the vibration machine is ignored. Most test failures occur when the test item goes into resonance, and the reaction force becomes very large. It has long been recognized that the large reaction force is a test artifact which does not occur with the lightweight, flexible mounting structures characteristic of spacecraft and space vehicles. In new vibration tests, both the motion and the force provided to the test item by the vibration machine are controlled, so that the vibration ride experienced by the test item is as in flight.

  15. Role of Kv4.3 in Vibration-Induced Muscle Pain in the Rat.

    PubMed

    Conner, Lindsay B; Alvarez, Pedro; Bogen, Oliver; Levine, Jon D

    2016-04-01

    We hypothesized that changes in the expression of voltage-gated potassium channel (Kv) 4.3 contribute to the mechanical hyperalgesia induced by vibration injury, in a rodent model for hand-arm vibration syndrome in humans. Here we show that the exposure of the gastrocnemius muscle to vibration injury induces muscle hyperalgesia that is accompanied by a significant downregulation of Kv4.3 in affected sensory nerve fibers in dorsal root ganglia. We additionally show that the intrathecal administration of antisense oligonucleotides for Kv4.3 messenger RNA itself induces muscle hyperalgesia in the rat. Our results suggest that attenuation in the expression of Kv4.3 may contribute to neuropathic pain in people affected by hand-arm vibration syndrome. Our findings establish Kv4.3 as a potential molecular target for the treatment of hand-arm vibration syndrome. Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

  16. Frequency-dependent Effects of Vibration on Physiological Systems: Experiments with Animals and other Human Surrogates

    PubMed Central

    KRAJNAK, Kristine; RILEY, Danny A.; WU, John; MCDOWELL, Thomas; WELCOME, Daniel E.; XU, Xueyan S.; DONG, Ren G.

    2015-01-01

    Occupational exposure to vibration through the use of power- and pneumatic hand-tools results in cold-induced vasospasms, finger blanching, and alterations in sensorineural function. Collectively, these symptoms are referred to as hand-arm vibration syndrome (HAVS). Currently the International Standards Organization (ISO) standard ISO 5349-1 contains a frequency-weighting curve to help workers and employers predict the risk of developing HAVS with exposure to vibration of different frequencies. However, recent epidemiological and experimental evidence suggests that this curve under-represents the risk of injuries to the hands and fingers induced by exposure to vibration at higher frequencies (>100 Hz). To improve the curve, better exposure-response data need to be collected. The goal of this review is to summarize the results of animal and computational modeling studies that have examined the frequency-dependent effects of vibration, and discuss where additional research would be beneficial to fill these research gaps. PMID:23060248

  17. 1993 Sexually Transmitted Diseases Treatment Guidelines.

    ERIC Educational Resources Information Center

    Journal of School Health, 1994

    1994-01-01

    Prevention and control of sexually transmitted diseases is based on education of at-risk persons, detection, effective diagnosis and treatment, and evaluation, treatment, and counseling of sex partners. The article presents guidelines for secondary prevention, discussing prevention methods, prevention messages, HIV prevention counseling, partner…

  18. 1993 Sexually Transmitted Diseases Treatment Guidelines.

    ERIC Educational Resources Information Center

    Journal of School Health, 1994

    1994-01-01

    Prevention and control of sexually transmitted diseases is based on education of at-risk persons, detection, effective diagnosis and treatment, and evaluation, treatment, and counseling of sex partners. The article presents guidelines for secondary prevention, discussing prevention methods, prevention messages, HIV prevention counseling, partner…

  19. Fluid power-transmitting gas bearing

    NASA Technical Reports Server (NTRS)

    Collins, D.; De Furia, R.; Ezekiel, F.; Yang, P.

    1968-01-01

    Fluid power-transmitting gas bearing was designed that is essentially frictionless, stable, and highly efficient. The two basic components of this design are the base assembly and the upper plate. System could be a fluidic control system, a momentum exchange or reaction jet device.

  20. Mycoplasma genitalium: An emergent sexually transmitted disease?

    PubMed

    Manhart, Lisa E

    2013-12-01

    This article summarizes the epidemiologic evidence linking Mycoplasma genitalium to sexually transmitted disease syndromes, including male urethritis, and female cervicitis, pelvic inflammatory disease, infertility, and adverse birth outcomes. It discusses the relationship of this bacterium to human immunodeficiency virus infection and reviews the available literature on the efficacy of standard antimicrobial therapies against M genitalium.

  1. Survey of Research on Sexually Transmitted Diseases.

    ERIC Educational Resources Information Center

    Centers for Disease Control (DHHS/PHS), Atlanta, GA.

    This survey covers periodical literature published in the field of research on sexually transmitted diseases during 1985. The articles cover the following diseases: (1) genital chlamydial infection; (2) gonorrhea; (3) genital herpes infection; (4) human papillomavirus infection; (5) acquired immunodeficiency syndrome (AIDS); (6) genital…

  2. Digital media and sexually transmitted infections.

    PubMed

    Gilliam, Melissa; Chor, Julie; Hill, Brandon

    2014-10-01

    Digital media, including the Internet, social networking sites, text messaging, and mobile applications, are ubiquitous among adolescents and young adults. These platforms enable users to obtain important information on a multitude of health topics, they may facilitate risk-taking behaviors, and they can be key components of health interventions. The purpose of this article is to review the recent literature on digital media and sexually transmitted infections, discussing their role in potentiating and reducing risk. This review demonstrates adolescents' use of digital media to gather information on health topics and discusses significant privacy concerns regarding using media to explore sexual health information. Although several studies demonstrate an association between social media and increased sexual risk-taking behaviors, this relationship is not fully understood. Digital media-based interventions are increasingly being developed to either reduce risk or improve management of sexually transmitted infections. As greater numbers of adolescents use digital media, the potential for these platforms to influence sexual risk-taking behaviors is significant. Additional research is needed to better understand the impact of digital media on sexually transmitted infection risk and to develop social media-based interventions to improve sexually transmitted infection outcomes.

  3. Inductive Reasoning about Causally Transmitted Properties

    ERIC Educational Resources Information Center

    Shafto, Patrick; Kemp, Charles; Bonawitz, Elizabeth Baraff; Coley, John D.; Tenenbaum, Joshua B.

    2008-01-01

    Different intuitive theories constrain and guide inferences in different contexts. Formalizing simple intuitive theories as probabilistic processes operating over structured representations, we present a new computational model of category-based induction about causally transmitted properties. A first experiment demonstrates undergraduates'…

  4. Sexually Transmitted Diseases: A Selective, Annotated Bibliography.

    ERIC Educational Resources Information Center

    Planned Parenthood Federation of America, Inc., New York, NY. Education Dept.

    This document contains a reference sheet and an annotated bibliography concerned with sexually transmitted diseases (STD). The reference sheet provides a brief, accurate overview of STDs which includes both statistical and background information. The bibliography contains 83 entries, listed alphabetically, that deal with STDs. Books and articles…

  5. Survey of Research on Sexually Transmitted Diseases.

    ERIC Educational Resources Information Center

    Centers for Disease Control (DHHS/PHS), Atlanta, GA.

    This survey covers periodical literature published in the field of research on sexually transmitted diseases during 1985. The articles cover the following diseases: (1) genital chlamydial infection; (2) gonorrhea; (3) genital herpes infection; (4) human papillomavirus infection; (5) acquired immunodeficiency syndrome (AIDS); (6) genital…

  6. Sexually Transmitted Diseases: A Selective, Annotated Bibliography.

    ERIC Educational Resources Information Center

    Planned Parenthood Federation of America, Inc., New York, NY. Education Dept.

    This document contains a reference sheet and an annotated bibliography concerned with sexually transmitted diseases (STD). The reference sheet provides a brief, accurate overview of STDs which includes both statistical and background information. The bibliography contains 83 entries, listed alphabetically, that deal with STDs. Books and articles…

  7. Inductive Reasoning about Causally Transmitted Properties

    ERIC Educational Resources Information Center

    Shafto, Patrick; Kemp, Charles; Bonawitz, Elizabeth Baraff; Coley, John D.; Tenenbaum, Joshua B.

    2008-01-01

    Different intuitive theories constrain and guide inferences in different contexts. Formalizing simple intuitive theories as probabilistic processes operating over structured representations, we present a new computational model of category-based induction about causally transmitted properties. A first experiment demonstrates undergraduates'…

  8. A viral infection of the hand commonly seen after the feast of sacrifice: human orf (orf of the hand).

    PubMed

    Uzel, M; Sasmaz, S; Bakaris, S; Cetinus, E; Bilgic, E; Karaoguz, A; Ozkul, A; Arican, O

    2005-08-01

    Orf of the hand is an uncommon zoonotic infection caused by a dermotropic DNA virus that belongs to the Parapoxvirus genus of the family Poxviridae. It is transmitted to humans through contact with infected sheep and goats and is reported as an occupational disease. We report nine cases of human orf seen in the hands of individuals, who were not occupationally exposed, after the feast of sacrifice in Turkey. Three cases were teachers and six out of the nine were housewives. We observed musculoskeletal complications and misdiagnoses. It is important to consider human orf in the differential diagnosis of hand lesions to prevent overtreatment and complications.

  9. Vibration control in accelerators

    SciTech Connect

    Montag, C.

    2011-01-01

    In the vast majority of accelerator applications, ground vibration amplitudes are well below tolerable magnet jitter amplitudes. In these cases, it is necessary and sufficient to design a rigid magnet support structure that does not amplify ground vibration. Since accelerator beam lines are typically installed at an elevation of 1-2m above ground level, special care has to be taken in order to avoid designing a support structure that acts like an inverted pendulum with a low resonance frequency, resulting in untolerable lateral vibration amplitudes of the accelerator components when excited by either ambient ground motion or vibration sources within the accelerator itself, such as cooling water pumps or helium flow in superconducting magnets. In cases where ground motion amplitudes already exceed the required jiter tolerances, for instance in future linear colliders, passive vibration damping or active stabilization may be considered.

  10. Vibration in textile mills.

    PubMed

    Sorainen, E

    1988-12-01

    The vibration in nine halls of the six weaving mills was measured in 1978-80. The measurements were taken at regular intervals in the working area of the weavers, which was the wooden support attached to the machine or the floor of the textile mill. The accelerometer was mounted with screws onto the working area, and all vibration samples were analyzed immediately, in situ. The vibration of the floor was tangent to or exceeded slightly the "reduced comfort boundary" specified in International Standard ISO 2631/1 (1985) only in the areas where the floor was not against the ground. The greatest amount of vibration occurred on the supports which had been attached to the machines. On these supports the vibration in places exceeded the "fatigue-decreased proficiency boundary."

  11. Photovoltaic device having light transmitting electrically conductive stacked films

    DOEpatents

    Weber, Michael F.; Tran, Nang T.; Jeffrey, Frank R.; Gilbert, James R.; Aspen, Frank E.

    1990-07-10

    A light transmitting electrically conductive stacked film, useful as a light transmitting electrode, including a first light transmitting electrically conductive layer, having a first optical thickness, a second light transmitting layer, having a second optical thickness different from the optical thickness of the first layer, and an electrically conductive metallic layer interposed between and in initimate contact with the first and second layers.

  12. Effect of Vibrations on Transportation System

    NASA Astrophysics Data System (ADS)

    Birlik, Gülin; Sezgin, Önder Cem

    In overly populated cities people living in suburban areas have to endure long journeys in order to reach their job sites. Whether they go by train, bus or by car they are inevitably exposed to vibrations, of considerable magnitude, in vertical (z) and lateral (x, y) directions. The immediate effect of vibration exposure is the fatigue of ones' muscles. This is verified by the blood and saliva analysis of the volunteers travelling in a train. Their lactic acid levels were increased by 34% at the end of a 5 hr journey. The most affected people by vibration were, without doubt, the train operators and bus drivers. 42% of the suburban train operators had pain complaints at their waists. az(floor) in the machinist cabin of a suburban train was measured to be, on the average, 0.23 m/s2. Max peak was 1.34 m/s2. The bus and car drivers were exposed to lower vibrations but they were exposed to multiple shocks originating from the non-standardized humps placed on the roads. Peak az(seat) = 0.054 m/s2 (f = 5.25 Hz) (vcar = 30 km/hr) on an asphalt road increased considerably while crossing over a hump. This value was 1.27 m/s2 (f = 4.5 Hz) in case of bus drivers (vbus = 20 km/hr). Studies have been done to provide practical measures for the reduction of the vibrations transmitted to the drivers. The waist belts filled with fluids of different viscosities prepared for this purpose seemed to be promising. The cushions filled with glycerin and gel were observed to be the best alternatives.

  13. Design, fabrication and testing of two electrohydraulic vibration isolation systems for helicopter environments

    NASA Technical Reports Server (NTRS)

    Allen, R. E.; Calcaterra, P. C.

    1972-01-01

    Two electrohydraulic vibration isolation systems were designed and fabricated to reduce the vertical vibrations transmitted to the XH-51N research helicopter cabin at the blade passage frequency (18 Hz) and its first harmonic (36 Hz). Hydraulic power and electrical control are provided to two separate servoactuators from a common power supply and control electronics package located behind the pilot's seat. One servoactuator is installed between the cabin and fuselage and replaces an existing passive spring. A second servoactuator is mounted between the existing seat and cabin floor. Both servoactuators incorporate a mechanical failsafe design. The control electronics circuitry provides automatic tracking of the blade passage frequency. Results of laboratory, environmental and ground vibration tests employing an XH-51A stripped down helicopter fuselage show that the active cabin isolator reduces the vertical vibrations transmitted from the fuselage attachment point to the cabin attachment point at 18 and 36 Hz (or as an alternative, 6 Hz) by better than 90 percent.

  14. Vibration isolation of automotive vehicle engine using periodic mounting systems

    NASA Astrophysics Data System (ADS)

    Asiri, S.

    2005-05-01

    Customer awareness and sensitivity to noise and vibration levels have been raised through increasing television advertisement, in which the vehicle noise and vibration performance is used as the main market differentiation. This awareness has caused the transportation industry to regard noise and vibration as important criteria for improving market shares. One industry that tends to be in the forefront of the technology to reduce the levels of noise and vibration is the automobile industry. Hence, it is of practical interest to reduce the vibrations induced structural responses. The automotive vehicle engine is the main source of mechanical vibrations of automobiles. The engine is vulnerable to the dynamic action caused by engine disturbance force in various speed ranges. The vibrations of the automotive vehicle engines may cause structural failure, malfunction of other parts, or discomfort to passengers because of high level noise and vibrations. The mounts of the engines act as the transmission paths of the vibrations transmitted from the excitation sources to the body of the vehicle and passengers. Therefore, proper design and control of these mounts are essential to the attenuation of the vibration of platform structures. To improve vibration resistant capacities of engine mounting systems, vibration control techniques may be used. For instance, some passive and semi-active dissipation devices may be installed at mounts to enhance vibration energy absorbing capacity. In the proposed study, a radically different concept is presented whereby periodic mounts are considered because these mounts exhibit unique dynamic characteristics that make them act as mechanical filters for wave propagation. As a result, waves can propagate along the periodic mounts only within specific frequency bands called the "Pass Bands" and wave propagation is completely blocked within other frequency bands called the "Stop Bands". The experimental arrangements, including the design of

  15. Simulation of Satellite Vibration Test

    NASA Astrophysics Data System (ADS)

    Bettacchioli, Alain

    2014-06-01

    During every mechanical qualification test of satellites on vibrator, we systematically notice beating phenomena that appear every time we cross a mode's frequency. There could lead to an over-qualification of the tested specimen when the beating reaches a maximum and a under-qualification when the beating passes by a minimum. On a satellite, three lateral modes raise such a problem in a recurring way: the first structure mode (between 10 and 15 hertz) and the two tanks modes (between 35 and 50 hertz).To step forward in the resolution of this problem, we are developing a simulator which is based on the identification of the responses of the accelerometers that are fixed on the satellite and on the shaker slip table. The estimated transfer functions then allow to reconstruct at once the sensors response and the drive which generated them.For the simulation, we do not select all the sensors but only those on the slip table and those used to limit the input level (notching). We may also add those which were close to generate a notching.To perform its calculations, the simulator reproduces on one hand the unity amplitude signal (cola) which serves as frequency reference for the sweep achievement (generally 3 octaves per minute from 5 to 100 and even 150 Hertz), and on the other hand, the vibrator control loop. The drive amplitude is calculated at each cola's period by taking into account a compression factor. The control applied through the amplifier to the shaker coil is the product of this amplitude by the cola. The simulated measurements are updated at each sampling period thanks to the propagation of the identified model. The superposition of these curves on those supplied by real sensors during the tests allows to validate the simulation.Thereby, it seems possible to actively control the beatings thanks to a real-time corrector which uses these identifications.

  16. Quantitative thermal perception thresholds relative to exposure to vibration

    PubMed Central

    Nilsson, T; Lundstrom, R

    2001-01-01

    OBJECTIVES—To assess the risk of disturbed thermal perception relative to exposure to vibration, to investigate a possible exposure-response relation and to analyse a possible relation between thermal perception and sensory symptoms.
METHODS—The study was based on a cross section of 123 male workers exposed to vibration and 62 male workers who were not exposed. Thermal perception of cold, warmth, and heat pain was bilaterally determined from the thenar eminence by the method of limits. Perception of cold and warmth were also tested in the second digit. Personal energy equivalent exposure to vibration was measured for all subjects. Vibration was measured in accordance with International Standards Organisation (ISO) 5349 and assessed separately for the left and right hand.
RESULTS—Combining exposure times and intensities gave the left hand an 0.80 exposure to vibration compared with the right. The risk of having contracted reduced thermal perception was increased at all test sites. The risk was higher for the thenar measurements than the finger measurements. A yearly extra contribution of 4000 mh/s2 in cumulative exposure increases the risk of contracting a wider neutral zone by 18% (95% confidence interval (95% CI) 1.06 to 1.32) for the right and 18% (1.05 to 1.32) for the left hand side. Subjects with symptoms of nocturnal paraesthesia had a rate ratio (95% CI) of 2.80 (1.17 to 6.67) for the right hand and 2.72 (1.12 to 6.63) for the left hand for increased neutral zones at the thenar eminence.
CONCLUSIONS—The results indicate thermal sensory impairment related to cumulative exposure to vibration. The effect appeared at vibration levels below the current guiding standard. Quantitative sensory testing of thermal perception offers the chance to assess this specific hazard to the peripheral sensorineural system associated with hand intensive work entailing vibration.


Keywords: quantitative thermal perception; heat pain; vibration

  17. The Shock and Vibration Bulletin. Part 4. Underwater Problems, Environments and Measurements

    DTIC Science & Technology

    1974-08-01

    Bradshaw, Jr., U.S. Army Engineer Division, Huntsville, Alabama and H.H. Yen, Sperry -Rand Corporation, Huntsville, Alabama POPPING MOTOR DOME SHOCK...ANALYSIS OF TRANSPORT AIRCRAFT VIBRATION DATA Roger E. Thaller and Jerome Pearson Air Force Flight Dynamics Laboratory Wright-Patterson AFB, Ohio The...Recommendid Vibration Test Envelope REFERENCES 1. Magrath, H.A., Rogers , O.R., and Crimes, T.K.: Sho<:k and Vibration Hand- book, (Harris, CM. a»id

  18. The Low-Temperature Vibrational Behavior of Pentaerythritol Tetranitrate

    DTIC Science & Technology

    2008-06-01

    reversibility of the symmetry change. 15. SUBJECT TERMS vibrational spectroscopy, high pressure , pentaerythritol tetranitrate, diamond anvil cell...available diamond anvil cells, there has been a rising interest in the past 5 years in the high - pressure behavior of energetic materials. (a) (b) (c...Stress within the diamond anvil cell can be controlled through the use of different pressure -transmitting media, which decreases or increases the strain

  19. Transmission of vertical whole body vibration to the human body.

    PubMed

    Kiiski, Juha; Heinonen, Ari; Järvinen, Teppo L; Kannus, Pekka; Sievänen, Harri

    2008-08-01

    According to experimental studies, low-amplitude high-frequency vibration is anabolic to bone tissue, whereas in clinical trials, the bone effects have varied. Given the potential of whole body vibration in bone training, this study aimed at exploring the transmission of vertical sinusoidal vibration to the human body over a wide range of applicable amplitudes (from 0.05 to 3 mm) and frequencies (from 10 to 90 Hz). Vibration-induced accelerations were assessed with skin-mounted triaxial accelerometers at the ankle, knee, hip, and lumbar spine in four males standing on a high-performance vibration platform. Peak vertical accelerations of the platform covered a range from 0.04 to 19 in units of G (Earth's gravitational constant). Substantial amplification of peak acceleration could occur between 10 and 40 Hz for the ankle, 10 and 25 Hz for the knee, 10 and 20 Hz for the hip, and at 10 Hz for the spine. Beyond these frequencies, the transmitted vibration power declined to 1/10th-1/1000 th of the power delivered by the platform. Transmission of vibration to the body is a complicated phenomenon because of nonlinearities in the human musculoskeletal system. These results may assist in estimating how the transmission of vibration-induced accelerations to body segments is modified by amplitude and frequency and how well the sinusoidal waveform is maintained. Although the attenuation of vertical vibration at higher frequencies is fortunate from the aspect of safety, amplitudes >0.5 mm may result in greater peak accelerations than imposed at the platform and thus pose a potential hazard for the fragile musculoskeletal system.

  20. Green stink bug Nezara viridula detects differences in amplitude between courtship song vibrations at stem and petiolus.

    PubMed

    Stritih, Nataša; Virant-Doberlet, Meta; Čokl, Adrej

    2000-01-01

    Green stink bug Nezara viridula courtship songs are transmitted through plants as substrate vibrations. The amplitude of the vibrations is different at different distances from the source of vibration and at different locations on the plant. Amplitudes of the local vibration were measured on stem and petioli of the bean plant (Phaseolus vulgaris) with a Laser-Doppler vibrometer. Differences of the amplitudes of vibration between adjacent points around the nodes were large enough to release differential nerve activities of vibration receptor cells of different legs. There was no correlation between the signal amplitude and the distance from the singing bug, however; the differences in amplitudes of vibrations between the stem and the adjacent petioli of leaves potentially permitted direction finding in the green stink bug males.

  1. Green stink bug Nezara viridula detects differences in amplitude between courtship song vibrations at stem and petiolus.

    PubMed

    Stritih, Nataša; Virant-Doberlet, Meta; Čokl, Adrej

    2000-07-01

    Green stink bug Nezara viridula courtship songs are transmitted through plants as substrate vibrations. The amplitude of the vibrations is different at different distances from the source of vibration and at different locations on the plant. Amplitudes of the local vibration were measured on stem and petioli of the bean plant (Phaseolus vulgaris) with a Laser-Doppler vibrometer. Differences of the amplitudes of vibration between adjacent points around the nodes were large enough to release differential nerve activities of vibration receptor cells of different legs. There was no correlation between the signal amplitude and the distance from the singing bug, however; the differences in amplitudes of vibrations between the stem and the adjacent petioli of leaves potentially permitted direction finding in the green stink bug males.

  2. Design and experiment of human hand motion driven electromagnetic energy harvester using dual Halbach magnet array

    NASA Astrophysics Data System (ADS)

    Salauddin, M.; Park, Jae Y.

    2017-03-01

    We present a dual Halbach array electromagnetic energy harvester that generates significant power from hand shaking vibration. The magnetic-spring configuration is employed for generating sufficient power from the hand motion of irregular and low-frequency vibrations. However, significant power generation at low-frequency vibrations is challenging because the power flow decreases as the frequency decreases; moreover, designing a spring-mass system that is suitable for low-frequency-vibration energy harvesting is difficult. In this work, our proposed device overcomes both of these challenges by using a dual Halbach array and magnetic springs. During the experiment, vibration was applied in a horizontal direction to reduce the gravity effect on the Halbach-array structure. To achieve an increased power generation at low-amplitude and low-frequency vibrations, the magnetic structure of the dual Halbach array and the magnetic springs were optimized in terms of the operating frequency and the power density. A prototype was fabricated and tested both using a vibration exciter and by manual hand-shaking. The fabricated device showed resonant behavior during the vibration exciter test. For the vibration exciter test, the prototype device offers a maximum average power of 2.92 mW to a 62 Ω optimum load, at a 6 Hz resonance frequency and under a 0.5 g acceleration. The prototype device is capable of delivering a maximum average power of 2.27 mW from hand shaking. The fabricated device exhibited a normalized power density 0.46 mW cm-2g-2 which is very high compared to the current state-of-the-art devices, representing its ability in powering portable and wearable smart devices from extremely low frequency vibration.

  3. Hand transplant surgery

    PubMed Central

    Nassimizadeh, AK; Power, D

    2014-01-01

    In September 1998 the world’s first hand transplant was performed in Lyon, France. A new era in reconstructive surgery had begun. This case highlighted the potential for composite tissue allotransplantation (CTA). While CTA is not a new technique, it unifies the principles of reconstructive microsurgery and transplant surgery, achieving the goals of absolute correction of a defect with anatomically and physiologically identical tissue with none of the issues of donor site morbidity associated with autologous tissue transfer. The adoption of this technique for non-life threatening conditions to improve quality of life has generated a number of new ethical considerations. Additionally, the prominence of transplanted hands has led to much discussion around the issue of body identity and psychological assessment of potential recipients. This is fundamental to any hand transplantation programme. With the advent of hand transplantation dawning in the UK, we review the many ethical considerations that contribute to this new frontier. PMID:25350176

  4. A Myoelectric Hand Splint

    ERIC Educational Resources Information Center

    Silverstein, Frances; And Others

    1974-01-01

    Development of a myoelectrically controlled hand splint permitting ambulating mobility of the user is discussed. The role of occupational therapy in the research and design of the device and the training of the patient are emphasized. (Authors)

  5. A Myoelectric Hand Splint

    ERIC Educational Resources Information Center

    Silverstein, Frances; And Others

    1974-01-01

    Development of a myoelectrically controlled hand splint permitting ambulating mobility of the user is discussed. The role of occupational therapy in the research and design of the device and the training of the patient are emphasized. (Authors)

  6. Hand transplant surgery.

    PubMed

    Nassimizadeh, M; Nassimizadeh, A K; Power, D

    2014-11-01

    In September 1998 the world's first hand transplant was performed in Lyon, France. A new era in reconstructive surgery had begun. This case highlighted the potential for composite tissue allotransplantation (CTA). While CTA is not a new technique, it unifies the principles of reconstructive microsurgery and transplant surgery, achieving the goals of absolute correction of a defect with anatomically and physiologically identical tissue with none of the issues of donor site morbidity associated with autologous tissue transfer. The adoption of this technique for non-life threatening conditions to improve quality of life has generated a number of new ethical considerations. Additionally, the prominence of transplanted hands has led to much discussion around the issue of body identity and psychological assessment of potential recipients. This is fundamental to any hand transplantation programme. With the advent of hand transplantation dawning in the UK, we review the many ethical considerations that contribute to this new frontier.

  7. Sexually transmitted diseases: magnitude, determinants and consequences.

    PubMed

    Aral, S O

    2001-04-01

    Sexually transmitted diseases (STDs) including human immuno-deficiency virus (HIV) infections constitute a major reproductive health burden for sexually-active individuals. The short-term and long-term consequences of STD have been well documented and include genital and other cancers, pelvic inflammatory disease, ectopic pregnancy, infertility, and adverse outcomes of pregnancy including pre-term delivery and low birth weight. The burden of sexually transmitted infections falls disproportionately on the young, the poor, minorities and women. At the societal level, there is a continuing need to educate people, particularly adolescents, about their risk for STDs and their sequelae and to increase the use of barrier methods including condoms. Policy decisions that facilitate more open discussion of sexuality and STDs, and that expand the accessibility and acceptability of sexual risk assessment, STD screening and treatment services would help decrease STD rates in the United States to levels similar to those observed in other industrialized countries.

  8. Advances in understanding paternally transmitted Chromosomal Abnormalities

    SciTech Connect

    Marchetti, F; Sloter, E; Wyrobek, A J

    2001-03-01

    Multicolor FISH has been adapted for detecting the major types of chromosomal abnormalities in human sperm including aneuploidies for clinically-relevant chromosomes, chromosomal aberrations including breaks and rearrangements, and other numerical abnormalities. The various sperm FISH assays have been used to evaluate healthy men, men of advanced age, and men who have received mutagenic cancer therapy. The mouse has also been used as a model to investigate the mechanism of paternally transmitted genetic damage. Sperm FISH for the mouse has been used to detect chromosomally abnormal mouse sperm, while the PAINT/DAPI analysis of mouse zygotes has been used to evaluate the types of chromosomal defects that can be paternally transmitted to the embryo and their effects on embryonic development.

  9. Intracellular recording from a spider vibration receptor.

    PubMed

    Gingl, Ewald; Burger, Anna-M; Barth, Friedrich G

    2006-05-01

    The present study introduces a new preparation of a spider vibration receptor that allows intracellular recording of responses to natural mechanical or electrical stimulation of the associated mechanoreceptor cells. The spider vibration receptor is a lyriform slit sense organ made up of 21 cuticular slits located on the distal end of the metatarsus of each walking leg. The organ is stimulated when the tarsus receives substrate vibrations, which it transmits to the organ's cuticular structures, reducing the displacement to about one tenth due to geometrical reasons. Current clamp recording was used to record action potentials generated by electrical or mechanical stimuli. Square pulse stimulation identified two groups of sensory cells, the first being single-spike cells which generated only one or two action potentials and the second being multi-spike cells which produced bursts of action potentials. When the more natural mechanical sinusoidal stimulation was applied, differences in adaptation rate between the two cell types remained. In agreement with prior extracellular recordings, both cell types showed a decrease in the threshold tarsus deflection with increasing stimulus frequency. Off-responses to mechanical stimuli have also been seen in the metatarsal organ for the first time.

  10. Quantitative neurosensory findings, symptoms and signs in young vibration exposed workers

    PubMed Central

    2013-01-01

    Background Long-term exposure to hand-held vibrating tools may cause the hand arm vibration syndrome (HAVS) including vibration induced white fingers and sensorineural symptoms. The aim was to study early neurosensory effects by quantitative vibrotactile and monofilament tests in young workers with hand-held vibration exposure. Methods This cross-sectional study consisted of 142 young, male machine shop and construction workers with hand-held exposure to vibrating tools. They were compared with 41 non-vibration exposed subjects of the same age-group. All participants passed a structured interview, answered several questionnaires and had a physical examination including the determination of vibrotactile perception thresholds (VPTs) at two frequencies (31.5 and 125 Hz) and Semmes Weinstein’s Monofilament test. Results In the vibration exposed group 8% of the workers reported episodes of tingling sensations and 10% numbness in their fingers. Approximately 5–10% of the exposed population displayed abnormal results on monofilament tests. The vibrotactile testing showed significantly increased VPTs for 125 Hz in dig II bilaterally (right hand, p = 0.01; left hand, p = 0.024) in the vibration exposed group. A multiple regression analysis (VPT - dependent variable; age, height, examiner and five different vibration dose calculations – predictor variables) in dig II bilaterally showed rather low R2-values. None of the explanatory variables including five separately calculated vibration doses were included in the models, neither for the total vibration exposed group, nor for the highest exposed quartile. A logistic multiple regression analysis (result of monofilament testing - dependent variable; age, height, examiner and five vibration dose calculations – predictor variables) of the results of monofilament testing in dig II bilaterally gave a similar outcome. None of the independent variables including five calculated vibration doses were included in the

  11. The Office Management of Sexually Transmitted Diseases

    PubMed Central

    Crombie, Fionnella S.S.

    1987-01-01

    The family physician plays an important role in controlling the spread of sexually transmitted diseases. Accurate identification, diagnosis and treatment are essential in exercising this control. In addition, attention must be paid to educating patients and to treating their sexual contacts. This paper will review the management of some of the more common diseases including urethritis, vaginitis, cervicitis, herpes, genital warts and molluscum contagiosum. PMID:21263806

  12. Social Implications of Sexually Transmitted Diseases

    PubMed Central

    Delva, Dianne

    1983-01-01

    Changes in attitudes toward sexuality have contributed to the rise in incidence of sexually transmitted diseases. The persistence of social stigma towards STD acts as a barrier to treatment-seeking. The exaggerated threat of genital herpes has led to unnecessary suffering, anxiety and increased social stigma, but is unlikely to alter sexual behavior. A change in attitudes will be necessary if attempts to control the spread of STD are to be successful. PMID:21283431

  13. Inter-Plant Vibrational Communication in a Leafhopper Insect

    PubMed Central

    Eriksson, Anna; Anfora, Gianfranco; Lucchi, Andrea; Virant-Doberlet, Meta; Mazzoni, Valerio

    2011-01-01

    Vibrational communication is one of the least understood channels of communication. Most studies have focused on the role of substrate-borne signals in insect mating behavior, where a male and a female establish a stereotyped duet that enables partner recognition and localization. While the effective communication range of substrate-borne signals may be up to several meters, it is generally accepted that insect vibrational communication is limited to a continuous substrate. Until now, interplant communication in absence of physical contact between plants has never been demonstrated in a vibrational communicating insect. With a laser vibrometer we investigated transmission of natural and played back vibrational signals of a grapevine leafhopper, Scaphoideus titanus, when being transmitted between leaves of different cuttings without physical contact. Partners established a vibrational duet up to 6 cm gap width between leaves. Ablation of the antennae showed that antennal mechanoreceptors are not essential in detection of mating signals. Our results demonstrate for the first time that substrate discontinuity does not impose a limitation on communication range of vibrational signals. We also suggest that the behavioral response may depend on the signal intensity. PMID:21573131

  14. Whole-body vibration exercise in postmenopausal osteoporosis

    PubMed Central

    Mieszkowski, Jan; Niespodziński, Bartłomiej; Ciechanowska, Katarzyna

    2015-01-01

    The report of the World Health Organization (WHO) of 2008 defines osteoporosis as a disease characterized by low bone mass and an increased risk of fracture. Postmenopausal osteoporosis is connected to the decrease in estrogens concentration as a result of malfunction of endocrine ovarian function. Low estrogens concentration causes increase in bone demineralization and results in osteoporosis. Physical activity, as a component of therapy of patients with osteoporosis, has been used for a long time now. One of the forms of safe physical activity is the vibration training. Training is to maintain a static position or execution of specific exercises involving the appropriate muscles on a vibrating platform, the mechanical vibrations are transmitted to the body of the patient. According to the piezoelectric theory, pressure induces bone formation in the electrical potential difference, which acts as a stimulant of the process of bone formation. Whole body vibration increases the level of growth hormone and testosterone in serum, preventing sarcopenia and osteoporosis. The aim of this study was to review the literature on vibration exercise in patients with postmenopausal osteoporosis based on the PubMed and Medline database. While searching the database, the following key words were used ‘postmenopausal osteoporosis’ and ‘whole-body vibration exercise’. PMID:26327887

  15. Whole-body vibration exercise in postmenopausal osteoporosis.

    PubMed

    Weber-Rajek, Magdalena; Mieszkowski, Jan; Niespodziński, Bartłomiej; Ciechanowska, Katarzyna

    2015-03-01

    The report of the World Health Organization (WHO) of 2008 defines osteoporosis as a disease characterized by low bone mass and an increased risk of fracture. Postmenopausal osteoporosis is connected to the decrease in estrogens concentration as a result of malfunction of endocrine ovarian function. Low estrogens concentration causes increase in bone demineralization and results in osteoporosis. Physical activity, as a component of therapy of patients with osteoporosis, has been used for a long time now. One of the forms of safe physical activity is the vibration training. Training is to maintain a static position or execution of specific exercises involving the appropriate muscles on a vibrating platform, the mechanical vibrations are transmitted to the body of the patient. According to the piezoelectric theory, pressure induces bone formation in the electrical potential difference, which acts as a stimulant of the process of bone formation. Whole body vibration increases the level of growth hormone and testosterone in serum, preventing sarcopenia and osteoporosis. The aim of this study was to review the literature on vibration exercise in patients with postmenopausal osteoporosis based on the PubMed and Medline database. While searching the database, the following key words were used 'postmenopausal osteoporosis' and 'whole-body vibration exercise'.

  16. Vibration Response of Multi Storey Building Using Finite Element Modelling

    NASA Astrophysics Data System (ADS)

    Chik, T. N. T.; Zakaria, M. F.; Remali, M. A.; Yusoff, N. A.

    2016-07-01

    Interaction between building, type of foundation and the geotechnical parameter of ground may trigger a significant effect on the building. In general, stiffer foundations resulted in higher natural frequencies of the building-soil system and higher input frequencies are often associated with other ground. Usually, vibrations transmitted to the buildings by ground borne are often noticeable and can be felt. It might affect the building and become worse if the vibration level is not controlled. UTHM building is prone to the ground borne vibration due to closed distance from the main road, and the construction activities adjacent to the buildings. This paper investigates the natural frequency and vibration mode of multi storey office building with the presence of foundation system and comparison between both systems. Finite element modelling (FEM) package software of LUSAS is used to perform the vibration analysis of the building. The building is modelled based on the original plan with the foundation system on the structure model. The FEM results indicated that the structure which modelled with rigid base have high natural frequency compare to the structure with foundation system. These maybe due to soil structure interaction and also the damping of the system which related to the amount of energy dissipated through the foundation soil. Thus, this paper suggested that modelling with soil is necessary to demonstrate the soil influence towards vibration response to the structure.

  17. Directional vibration sensing in the termite Macrotermes natalensis.

    PubMed

    Hager, Felix A; Kirchner, Wolfgang H

    2014-07-15

    Although several behavioural studies demonstrate the ability of insects to localise the source of vibrations, it is still unclear how insects are able to perceive directional information from vibratory signals on solid substrates, because time-of-arrival and amplitude difference between receptory structures are thought to be too small to be processed by insect nervous systems. The termite Macrotermes natalensis communicates using vibrational drumming signals transmitted along subterranean galleries. When soldiers are attacked by predators, they tend to drum with their heads against the substrate and create a pulsed vibration. Workers respond by a fast retreat into the nest. Soldiers in the vicinity start to drum themselves, leading to an amplification and propagation of the signal. Here we show that M. natalensis makes use of a directional vibration sensing in the context of colony defence. In the field, soldiers are recruited towards the source of the signal. In arena experiments on natural nest material, soldiers are able to localise the source of vibration. Using two movable platforms allowing us to vibrate the legs of the left and right sides of the body with a time delay, we show that the difference in time-of-arrival is the directional cue used for orientation. Delays as short as 0.2 ms are sufficient to be detected. Soldiers show a significant positive tropotaxis to the platform stimulated earlier, demonstrating for the first time perception of time-of-arrival delays and vibrotropotaxis on solid substrates in insects.

  18. Inter-plant vibrational communication in a leafhopper insect.

    PubMed

    Eriksson, Anna; Anfora, Gianfranco; Lucchi, Andrea; Virant-Doberlet, Meta; Mazzoni, Valerio

    2011-05-05

    Vibrational communication is one of the least understood channels of communication. Most studies have focused on the role of substrate-borne signals in insect mating behavior, where a male and a female establish a stereotyped duet that enables partner recognition and localization. While the effective communication range of substrate-borne signals may be up to several meters, it is generally accepted that insect vibrational communication is limited to a continuous substrate. Until now, interplant communication in absence of physical contact between plants has never been demonstrated in a vibrational communicating insect. With a laser vibrometer we investigated transmission of natural and played back vibrational signals of a grapevine leafhopper, Scaphoideus titanus, when being transmitted between leaves of different cuttings without physical contact. Partners established a vibrational duet up to 6 cm gap width between leaves. Ablation of the antennae showed that antennal mechanoreceptors are not essential in detection of mating signals. Our results demonstrate for the first time that substrate discontinuity does not impose a limitation on communication range of vibrational signals. We also suggest that the behavioral response may depend on the signal intensity.

  19. Vibration analysis and testing for the LLST optical module

    NASA Astrophysics Data System (ADS)

    Weatherwax, Michele S.; Doyle, Keith B.

    2014-09-01

    A lunar orbiting space terminal was recently developed as part of NASA's Lunar Laser Communications Demonstration program. The space terminal uses a 10 centimeter, inertially-stabilized telescope and a 0.5 watt beam to transmit data at up to 622Mbps between the Moon and one of several ground terminals on Earth. Tight coupling between analysis and testing was used to ensure both performance and survival requirements were met in the operational and non-operational vibration environments. Performance requirements were driven by the need to meet a 4.2 μrad pointing stability requirement in the operational vibration environment. A highly-correlated FEA model was developed using vibration testing to extrapolate the behavior of the system beyond the practical limits of the vibration test bed. The launch load non-operational vibration environment was simulated through both analysis and testing using force-limiting to avoid over designing and over testing the sensitive optics. The iterative and associated challenges of the vibration analysis and testing effort are discussed to show how those efforts helped enable the successful launch, deployment, and ultimately demonstration of NASA's first space laser communications program.

  20. Neuropathy in female dental personnel exposed to high frequency vibrations.

    PubMed Central

    Akesson, I; Lundborg, G; Horstmann, V; Skerfving, S

    1995-01-01

    OBJECTIVE--To evaluate early neuropathy in dental personnel exposed to high frequency vibrations. METHODS--30 dentists and 30 dental hygienists who used low and high speed hand pieces and ultrasonic scalers were studied, and 30 dental assistants and 30 medical nurses not exposed to vibration (all women). Vibrotactile sensibility, strength, motor performance, sensorineural symptoms and signs, and vascular symptoms in the hands, as well as mercury concentrations in biological samples and cervicobrachial symptoms, were studied. RESULTS--The two groups exposed to vibration had significant impairments of vibrotactile sensibility, strength, and motor performance, as well as more frequent sensorineural symptoms. In the dentists there were significant associations between the vibrotactile sensibility and strength, motor performance, superficial sensibility, and sensorineural symptoms. There were no associations between these findings and cervicobrachial symptoms, mercury concentrations, or smoking. There was no increase of vascular symptoms of the hands in the groups exposed to vibration. CONCLUSION--Dental hygienists and dentists had a slight neuropathy, which may be associated with their exposure to high frequency vibrations, and which may be detrimental to their work performance. Thus, development of safer equipment is urgent. PMID:7757164

  1. Connectionist networks learn to transmit chaos.

    PubMed

    Mpitsos, G J; Burton, R M; Creech, H C

    1988-09-01

    Evidence presented in the preceding paper indicates that the activity of some neurons during the generation of coordinated motor patterns may be attributable to chaos. Because even "simple" biological systems are difficult to control, we have used connectionist networks in order to inquire into the question of whether a chaotic signal originating in one part of the nervous system can be learned and transmitted by another. We have examined a number of different architectures, and report here the findings for a simple network consisting of one input unit, four hidden units, and one output unit. During training sessions, the input of the circuit was given analog values of either the 3.60 or 3.95 logistic equation, or of one variable of the three-variable Rössler attractor. The backpropagated error in the learning algorithm was a function of the difference between the input value and the output at each iteration. Iterations involving small changes in analog value resulted in good similarity between the input and output signals, but little learning occurred because of the small error propagated back to the synapses. With larger differences in the analog values (and larger feedback error) at each iteration, we found that networks learned to transmit different chaotic attractors. Once the network learned one input, it could transmit another without changing the synapses. Increasing the number of hidden units increased the rate of learning.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Imaging Arrays With Improved Transmit Power Capability

    PubMed Central

    Zipparo, Michael J.; Bing, Kristin F.; Nightingale, Kathy R.

    2010-01-01

    Bonded multilayer ceramics and composites incorporating low-loss piezoceramics have been applied to arrays for ultrasound imaging to improve acoustic transmit power levels and to reduce internal heating. Commercially available hard PZT from multiple vendors has been characterized for microstructure, ability to be processed, and electroacoustic properties. Multilayers using the best materials demonstrate the tradeoffs compared with the softer PZT5-H typically used for imaging arrays. Three-layer PZT4 composites exhibit an effective dielectric constant that is three times that of single layer PZT5H, a 50% higher mechanical Q, a 30% lower acoustic impedance, and only a 10% lower coupling coefficient. Application of low-loss multilayers to linear phased and large curved arrays results in equivalent or better element performance. A 3-layer PZT4 composite array achieved the same transmit intensity at 40% lower transmit voltage and with a 35% lower face temperature increase than the PZT-5 control. Although B-mode images show similar quality, acoustic radiation force impulse (ARFI) images show increased displacement for a given drive voltage. An increased failure rate for the multilayers following extended operation indicates that further development of the bond process will be necessary. In conclusion, bonded multilayer ceramics and composites allow additional design freedom to optimize arrays and improve the overall performance for increased acoustic output while maintaining image quality. PMID:20875996

  3. Vibration exposure and prevention in Finland.

    PubMed

    Starck, J; Pyykkö, I; Koskimies, K; Pekkarinen, J

    1994-05-01

    The number of annually compensated occupational diseases due to exposure to hand-arm vibration (HAV) has decreased during the last 15 years. The number of exposed workers has been declining in Finland, especially in forestry work, as harvesters have increasingly replaced manual chain saw operations. During the entire 1970s, forest work caused more cases of vibration-induced occupational diseases than all industrial branches together. The decrease is mainly due to the technical development of chain saws, but also to the effective health care services in Finland. Other factors such as warm transport, warm rest cabins in which to take pauses at work, warm meals, adequate protective clothing, and vocationally adjusted early medical rehabilitation have helped to cut down health hazards, especially in forest work. The number of new cases has been decreasing in Finland not only in forestry but also in other industries. In Finland a considerable amount of research has been conducted to hand-arm vibration, resulting in the increased awareness of the health risks related to certain occupations. This has helped to carry out the Primary Health Care Act (1972) followed by the Occupational Health Care Act (1979) which obligates employers to arrange occupational health care for their employees. We believe that the research activity has contributed significantly to achieving the present health in Finnish work places. The purpose of the present paper is to describe the cases of occupational exposure to HAV, and the effectiveness of different preventive measures in Finland.

  4. PREFACE: Vibrations at surfaces Vibrations at surfaces

    NASA Astrophysics Data System (ADS)

    Rahman, Talat S.

    2011-12-01

    This special issue is dedicated to the phenomenon of vibrations at surfaces—a topic that was indispensible a couple of decades ago, since it was one of the few phenomena capable of revealing the nature of binding at solid surfaces. For clean surfaces, the frequencies of modes with characteristic displacement patterns revealed how surface geometry, as well as the nature of binding between atoms in the surface layers, could be different from that in the bulk solid. Dispersion of the surface phonons provided further measures of interatomic interactions. For chemisorbed molecules on surfaces, frequencies and dispersion of the vibrational modes were also critical for determining adsorption sites. In other words, vibrations at surfaces served as a reliable means of extracting information about surface structure, chemisorption and overlayer formation. Experimental techniques, such as electron energy loss spectroscopy and helium-atom-surface scattering, coupled with infra-red spectroscopy, were continually refined and their resolutions enhanced to capture subtleties in the dynamics of atoms and molecules at surfaces. Theoretical methods, whether based on empirical and semi-empirical interatomic potential or on ab initio electronic structure calculations, helped decipher experimental observations and provide deeper insights into the nature of the bond between atoms and molecules in regions of reduced symmetry, as encountered on solid surfaces. Vibrations at surfaces were thus an integral part of the set of phenomena that characterized surface science. Dedicated workshops and conferences were held to explore the variety of interesting and puzzling features revealed in experimental and theoretical investigations of surface vibrational modes and their dispersion. One such conference, Vibrations at Surfaces, first organized by Harald Ibach in Juelich in 1980, continues to this day. The 13th International Conference on Vibrations at Surfaces was held at the University of

  5. Train-induced field vibration measurements of ground and over-track buildings.

    PubMed

    Zou, Chao; Wang, Yimin; Moore, James A; Sanayei, Masoud

    2017-01-01

    Transit-oriented development, such as metro depot and over-track building complexes, has expanded rapidly over the last 5years in China. Over-track building construction has the advantage of comprehensive utilization of land resources, ease of commuting to work, and provide funds for subway construction. But the high frequency of subway operations into and out of the depots can generate excessive vibrations that transmit into the over track buildings, radiate noise within the buildings, hamper the operation of vibration sensitive equipment, and adversely affect the living quality of the building occupants. Field measurements of vibration during subway operations were conducted at Shenzhen, China, a city of 10.62 million people in southern China. Considering the metro depot train testing line and throat area train lines were the main vibration sources, vibration data were captured in five measurement setups. The train-induced vibrations were obtained and compared with limitation of FTA criteria. The structure-radiated noise was calculated using measured vibration levels. The vertical vibration energy directly passed through the columns on both sides of track into the platform, amplifying vibration on the platform by up to 6dB greater than ground levels at testing line area. Vibration amplification around the natural frequency in the vertical direction of over-track building made the peak values of indoor floor vibration about 16dB greater than outdoor platform vibration. We recommend to carefully examining design of new over-track buildings within 40m on the platform over the throat area to avoid excessive vertical vibrations and noise. For both buildings, the measured vertical vibrations were less than the FTA limit. However, it is demonstrated that the traffic-induced high-frequency noise has the potential to annoy occupants on the upper floors.

  6. Novel active noise-reducing headset using earshell vibration control.

    PubMed

    Rafaely, Boaz; Carrilho, Joao; Gardonio, Paolo

    2002-10-01

    Active noise-reducing (ANR) headsets are available commercially in applications varying from aviation communication to consumer audio. Current ANR systems use passive attenuation at high frequencies and loudspeaker-based active noise control at low frequencies to achieve broadband noise reduction. This paper presents a novel ANR headset in which the external noise transmitted to the user's ear via earshell vibration is reduced by controlling the vibration of the earshell using force actuators acting against an inertial mass or the earshell headband. Model-based theoretical analysis using velocity feedback control showed that current piezoelectric actuators provide sufficient force but require lower stiffness for improved low-frequency performance. Control simulations based on experimental data from a laboratory headset showed that good performance can potentially be achieved in practice by a robust feedback controller, while a single-frequency real-time control experiment verified that noise reduction can be achieved using earshell vibration control.

  7. Hydrofoil vibration and noise reduction with leading edge isolation

    NASA Astrophysics Data System (ADS)

    Brungart, Timothy A.; Myer, Eric C.; Capone, Dean E.; Campbell, Robert L.

    2005-09-01

    A technique for reducing the vibration and noise from hydrofoils subject to unsteady hydrodynamic loads was demonstrated experimentally. Unsteady loads are generated when hydrofoils interact with approach-flow disturbances such as hull boundary layer turbulence or wakes from upstream rotors. Since the unsteady loads are known to be concentrated in the vicinity of the leading edge, a single stage vibration isolation mount was incorporated into a hydrofoil at its 20% chord location to inhibit the leading edge-generated unsteady loads from being transmitted to the remainder of the foil and any structures coupled to it. The hydrofoil was tested in a water tunnel facility with a wake generator placed upstream to produce the approach-flow disturbances. The reduction in the loading on the portion of the hydrofoil isolated from the leading edge was inferred from vibration measurements. Reductions of 5 to 10 dB were demonstrated.

  8. Identification of nonlinear anti-vibration isolator properties

    NASA Astrophysics Data System (ADS)

    Mezghani, Fares; Del Rincón, Alfonso Fernández; Souf, Mohamed Amine Ben; Fernandez, Pablo García; Chaari, Fakher; Viadero Rueda, Fernando; Haddar, Mohamed

    2017-06-01

    Vibrations are classified among the major problems for engineering structures. Anti-vibration isolators are used to absorb vibration energy and minimise transmitted force which can cause damage. The isolator is modelled as a parallel combination of stiffness and damping elements. The main purpose of the model is to enable designers to predict the dynamic response of systems under different structural excitations and boundary conditions. A nonlinear identification method, discussed in this paper, aims to provide a tool for engineers to extract information about the nonlinear dynamic behaviour using measured data from experiments. The proposed method is demonstrated and validated with numerical simulations. Thus, this technique is applied to determine the nonlinear parameters of a commercial metal mesh isolator. Nonlinear stiffness and nonlinear damping can decrease with the increase in the amplitude of the base excitation. The softening behaviour of the mesh isolator is clearly visible.

  9. A Study on Vibration Isolator for Reaction Wheel Assembly

    NASA Astrophysics Data System (ADS)

    Hatsutori, Yoichi; Nakasuka, Shinichi

    Reaction wheel assembly used as main actuator of an attitude control system can be a major source of disturbances. Although vibration isolator for a reaction wheel assembly is required to attenuate a disturbance, a control torque has to be transmitted for an attitude control of a satellite. This paper introduces a new design method of vibration isolator for reaction wheel assembly. Proposed method is based on H-infinity formulation and optimizes not only parameters of vibration isolator, but also parameters of satellite's controller simultaneously. At first, numerical model of a parallel link isolator is formulated. Next, the formulations of new design method and constraint conditions are described. After that, results of numerical analysis and availability of proposed method are shown.

  10. NIF Ambient Vibration Measurements

    SciTech Connect

    Noble, C.R.; Hoehler, M.S., S.C. Sommer

    1999-11-29

    LLNL has an ongoing research and development project that includes developing data acquisition systems with remote wireless communication for monitoring the vibrations of large civil engineering structures. In order to establish the capability of performing remote sensing over an extended period of time, the researchers needed to apply this technology to a real structure. The construction of the National Ignition Facility provided an opportunity to test the data acquisition system on a large structure to monitor whether the facility is remaining within the strict ambient vibration guidelines. This document will briefly discuss the NIF ambient vibration requirements and summarize the vibration measurements performed during the Spring and Summer of 1999. In addition, a brief description of the sensors and the data acquisition systems will be provided in Appendix B.

  11. Calculating impedance vibrator antennas

    NASA Astrophysics Data System (ADS)

    Eminov, S. I.

    2017-07-01

    The technique of analytical reversal of a hypersingular equation is used to solve the equation of an impedance vibrator antenna. A numerical method for solving the equation is developed, and its efficiency is demonstrated.

  12. Deviations of frequency and the mode of vibration of commercially available whole-body vibration training devices.

    PubMed

    Kaeding, T S

    2015-06-01

    Research in the field of whole body vibration (WBV) training and the use of it in practice might be hindered by the fact that WBV training devices generate and transmit frequencies and/or modes of vibration which are different to preset adjustments. This research project shall clarify how exact WBV devices apply the by manufacturer information promised preset frequency and mode of vibration. Nine professional devices for WBV training were tested by means of a tri-axial accelerometer. The accelerations of each device were recorded under different settings with a tri-axial accelerometer. Beneath the measurement of different combinations of preset frequency and amplitude the repeatability across 3 successive measurements with the same preset conditions and one measurement under loaded condition were carried out. With 3 exceptions (both Board 3000 & srt medical PRO) we did not find noteworthy divergences between preset and actual applied frequencies. In these 3 devices we found divergences near -25%. Loading the devices did not affect the applied frequency or mode of vibration. There were no important divergences measurable for the applied frequency and mode of vibration regarding repeatability. The results of our measurements cannot be generalized as we only measured one respectively at most two devices of one model in terms of a random sample. Based on these results we strongly recommend that user in practice and research should analyse their WBV training devices regarding applied frequency and mode of vibration.

  13. 2008 Vibrational Spectroscopy

    SciTech Connect

    Philip J. Reid

    2009-09-21

    The conference focuses on using vibrational spectroscopy to probe structure and dynamics of molecules in gases, liquids, and interfaces. The goal is to bring together a collection of researchers who share common interests and who will gain from discussing work at the forefront of several connected areas. The intent is to emphasize the insights and understanding that studies of vibrations provide about a variety of systems.

  14. Hands of early primates.

    PubMed

    Boyer, Doug M; Yapuncich, Gabriel S; Chester, Stephen G B; Bloch, Jonathan I; Godinot, Marc

    2013-12-01

    Questions surrounding the origin and early evolution of primates continue to be the subject of debate. Though anatomy of the skull and inferred dietary shifts are often the focus, detailed studies of postcrania and inferred locomotor capabilities can also provide crucial data that advance understanding of transitions in early primate evolution. In particular, the hand skeleton includes characteristics thought to reflect foraging, locomotion, and posture. Here we review what is known about the early evolution of primate hands from a comparative perspective that incorporates data from the fossil record. Additionally, we provide new comparative data and documentation of skeletal morphology for Paleogene plesiadapiforms, notharctines, cercamoniines, adapines, and omomyiforms. Finally, we discuss implications of these data for understanding locomotor transitions during the origin and early evolutionary history of primates. Known plesiadapiform species cannot be differentiated from extant primates based on either intrinsic hand proportions or hand-to-body size proportions. Nonetheless, the presence of claws and a different metacarpophalangeal [corrected] joint form in plesiadapiforms indicate different grasping mechanics. Notharctines and cercamoniines have intrinsic hand proportions with extremely elongated proximal phalanges and digit rays relative to metacarpals, resembling tarsiers and galagos. But their hand-to-body size proportions are typical of many extant primates (unlike those of tarsiers, and possibly Teilhardina, which have extremely large hands). Non-adapine adapiforms and omomyids exhibit additional carpal features suggesting more limited dorsiflexion, greater ulnar deviation, and a more habitually divergent pollex than observed plesiadapiforms. Together, features differentiating adapiforms and omomyiforms from plesiadapiforms indicate increased reliance on vertical prehensile-clinging and grasp-leaping, possibly in combination with predatory behaviors in

  15. Effect of Remote Sensory Noise on Hand Function Post Stroke

    PubMed Central

    Seo, Na Jin; Kosmopoulos, Marcella Lyn; Enders, Leah R.; Hur, Pilwon

    2014-01-01

    Hand motor impairment persists after stroke. Sensory inputs may facilitate recovery of motor function. This pilot study tested the effectiveness of tactile sensory noise in improving hand motor function in chronic stroke survivors with tactile sensory deficits, using a repeated measures design. Sensory noise in the form of subthreshold, white noise, mechanical vibration was applied to the wrist skin during motor tasks. Hand dexterity assessed by the Nine Hole Peg Test and the Box and Block Test and pinch strength significantly improved when the sensory noise was turned on compared with when it was turned off in chronic stroke survivors. The subthreshold sensory noise to the wrist appears to induce improvements in hand motor function possibly via neuronal connections in the sensoriomotor cortex. The approach of applying concomitant, unperceivable mechanical vibration to the wrist during hand motor tasks is easily adoptable for clinic use as well as unsupervised home use. This pilot study suggests a potential for a wristband-type assistive device to complement hand rehabilitation for stroke survivors with sensorimotor deficit. PMID:25477806

  16. A 6-DOF vibration isolation system for hydraulic hybrid vehicles

    NASA Astrophysics Data System (ADS)

    Nguyen, The; Elahinia, Mohammad; Olson, Walter W.; Fontaine, Paul

    2006-03-01

    This paper presents the results of vibration isolation analysis for the pump/motor component of hydraulic hybrid vehicles (HHVs). The HHVs are designed to combine gasoline/diesel engine and hydraulic power in order to improve the fuel efficiency and reduce the pollution. Electric hybrid technology is being applied to passenger cars with small and medium engines to improve the fuel economy. However, for heavy duty vehicles such as large SUVs, trucks, and buses, which require more power, the hydraulic hybridization is a more efficient choice. In function, the hydraulic hybrid subsystem improves the fuel efficiency of the vehicle by recovering some of the energy that is otherwise wasted in friction brakes. Since the operation of the main component of HHVs involves with rotating parts and moving fluid, noise and vibration are an issue that affects both passengers (ride comfort) as well as surrounding people (drive-by noise). This study looks into the possibility of reducing the transmitted noise and vibration from the hydraulic subsystem to the vehicle's chassis by using magnetorheological (MR) fluid mounts. To this end, the hydraulic subsystem is modeled as a six degree of freedom (6-DOF) rigid body. A 6-DOF isolation system, consisting of five mounts connected to the pump/motor at five different locations, is modeled and simulated. The mounts are designed by combining regular elastomer components with MR fluids. In the simulation, the real loading and working conditions of the hydraulic subsystem are considered and the effects of both shock and vibration are analyzed. The transmissibility of the isolation system is monitored in a wide range of frequencies. The geometry of the isolation system is considered in order to sustain the weight of the hydraulic system without affecting the design of the chassis and the effectiveness of the vibration isolating ability. The simulation results shows reduction in the transmitted vibration force for different working cycles of

  17. Transmission of Enterobius vermicularis eggs through hands of school children in rural South Africa.

    PubMed

    Cranston, Imogen; Potgieter, Natasha; Mathebula, Sammy; Ensink, Jeroen H J

    2015-10-01

    Enterobius vermicularis is a helminth that is difficult to control, is found globally, especially in crowded conditions, and can be transmitted from person to person by contaminated hands. A newly developed method for the quantification of helminth eggs on hands was tested among schoolchildren in a rural South African region to look at the role hands play in helminth infection, and to determine the risk factors for hand contamination. The study found 16.6% of participants' hands positive for helminth eggs, with E. vermicularis most commonly identified. Egg concentrations on hands ranged from 0 to 57 eggs/2 hands. Gender, toilet type used at home, and not reporting to wash hands with soap before eating were all associated with the presence of eggs on hands. The study highlights the need to improve sanitation facilities, and promote handwashing with soap in schools to prevent transmission of E. vermicularis. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

  18. Physical examination of the hand.

    PubMed

    Kenney, Raymond J; Hammert, Warren C

    2014-11-01

    Examination of the hand is an essential piece of a hand surgeon's skill set. This current concepts review presents a systematic process of performing a comprehensive physical examination of the hand including vascular, sensory, and motor assessments. Evaluations focused on specific hand diseases and injuries are also discussed. This information can be useful for any health care provider treating patients with hand conditions.

  19. Vibration studies of a lightweight three-sided membrane suitable for space application

    NASA Technical Reports Server (NTRS)

    Sewell, J. L.; Miserentino, R.; Pappa, R. S.

    1983-01-01

    Vibration studies carried out in a vacuum chamber are reported for a three-sided membrane with inwardly curved edges. Uniform tension was transmitted by thin steel cables encased in the edges. Variation of ambient air pressure from atmospheric to near vacuum resulted in increased response frequencies and amplitudes. The first few vibration modes measured in a near vacuum are shown to be predictable by a finite element structural analysis over a range of applied tension loads. The complicated vibration mode behavior observed during tests at various air pressures is studied analytically with a nonstructural effective air-mass approximation. The membrane structure is a candidate for reflective surfaces in space antennas.

  20. Mechanical hands illustrated

    SciTech Connect

    Kato, I.; Sadamoto, K.

    1987-01-01

    In the field of robotics, considerable effort is devoted to the development of effective multiple prehension manipulator systems. Most of these efforts have been directed toward attempts to duplicate certain functions of the human hand for industrial and medical applications. The human hand is an intricate and complex system capable of a multitude of sensory and actuation functions. It has approximately 20 degrees of freedom controlled by a large number of muscles compared to only 7 degrees of freedom for the arm and wrist. Since the primary function of a mechanical hand is to grasp or pinch different objects, not all the degrees of freedom are necessary for every robot or prosthetic device. Most practical tasks for manipulators have their special requirements and constraints which influence the design of their end effector. Consequently various hand configurations have to be designed to effectively provide the required functions for a particular application without additional complexity. The control of these functions is accomplished by suitable actuators. Miniature touch and pressure sensors which can be as small as 3 mm in size are used to control the grip. This book discusses the knowledge base in the field of robotics. It provides an excellent compilation of photographs, scaled drawings, and source material for a wide variety of mechanical hands for the user to choose from.

  1. Energy evaluation of protection effectiveness of anti-vibration gloves.

    PubMed

    Hermann, Tomasz; Dobry, Marian Witalis

    2017-09-01

    This article describes an energy method of assessing protection effectiveness of anti-vibration gloves on the human dynamic structure. The study uses dynamic models of the human and the glove specified in Standard No. ISO 10068:2012. The physical models of human-tool systems were developed by combining human physical models with a power tool model. The combined human-tool models were then transformed into mathematical models from which energy models were finally derived. Comparative energy analysis was conducted in the domain of rms powers. The energy models of the human-tool systems were solved using numerical simulation implemented in the MATLAB/Simulink environment. The simulation procedure demonstrated the effectiveness of the anti-vibration glove as a method of protecting human operators of hand-held power tools against vibration. The desirable effect is achieved by lowering the flow of energy in the human-tool system when the anti-vibration glove is employed.

  2. Spectroscopy and reactions of vibrationally excited transient molecules

    SciTech Connect

    Dai, H.L.

    1993-12-01

    Spectroscopy, energy transfer and reactions of vibrationally excited transient molecules are studied through a combination of laser-based excitation techniques and efficient detection of emission from the energized molecules with frequency and time resolution. Specifically, a Time-resolved Fourier Transform Emission Spectroscopy technique has been developed for detecting dispersed laser-induced fluorescence in the IR, visible and UV regions. The structure and spectroscopy of the excited vibrational levels in the electronic ground state, as well as energy relaxation and reactions induced by specific vibronic excitations of a transient molecule can be characterized from time-resolved dispersed fluorescence in the visible and UV region. IR emissions from highly vibrational excited levels, on the other hand, reveal the pathways and rates of collision induced vibrational energy transfer.

  3. Applications of hand-arm models in the investigation of the interaction between man and machine.

    PubMed

    Jahn, R; Hesse, M

    1986-08-01

    The mode of vibration of hand-held tools cannot be considered without knowledge of the influence of the operator's hand-arm system. Therefore some technical applications of hand-arm models were realized for drill hammers by the University of Dortmund. These applications are a software program to simulate the motion of machine components, a horizontal drilling jig, and a chucking device in a drilling rig.

  4. Sexually transmitted diseases in children in developing countries.

    PubMed

    Richens, J

    1994-08-01

    The populations of developing countries have younger age structures than the populations of more developed, Western countries. That is, children, adolescents, and youth constitute a far greater proportion of the populations of developing countries than in developed countries. These young people experiment with sex and sexual intercourse or have coitus on a regular basis depending upon their individual personalities and circumstances. The prevalence of sexually transmitted diseases (STD) among younger age groups in developing countries is not well documented. It may, however, be inferred on the basis of reported experience of STD in surveys of adolescents and young adults that many children are infected with STDs. Some young people have sex consensually, some are coaxed into it, and others are coerced. On the one hand, young children have been thought to contract STD by sitting on the laps of infected, scantily-clad adults where such limited attire is the norm. Close contact between youngsters such as communal sleeping, for example, could then facilitate the spread of the STD among children. Sex, consensual or otherwise, is not involved in such infection and transmission beyond the index adult. On the other hand, however, many children and adolescents are forced to have sexual relations and/or intercourse either directly against their will or as a result of the primal need to ensure their individual survival. For example, there are an estimated 100-200 million street children worldwide; many have little alternative but to sell sex to survive. When having sex, they may not use condoms because they are unaware of the STD risk they face, they have no access to free condoms, clients/employers/peers prevent them from using condoms, or due to a myriad of other reasons. Struggling to survive, many such kids place condom use very low on their list of priorities. Children and adolescents can also become infected and transmit STDs to others by engaging in sexual intercourse

  5. Force Limited Vibration Testing

    NASA Technical Reports Server (NTRS)

    Scharton, Terry; Chang, Kurng Y.

    2005-01-01

    This slide presentation reviews the concept and applications of Force Limited Vibration Testing. The goal of vibration testing of aerospace hardware is to identify problems that would result in flight failures. The commonly used aerospace vibration tests uses artificially high shaker forces and responses at the resonance frequencies of the test item. It has become common to limit the acceleration responses in the test to those predicted for the flight. This requires an analysis of the acceleration response, and requires placing accelerometers on the test item. With the advent of piezoelectric gages it has become possible to improve vibration testing. The basic equations have are reviewed. Force limits are analogous and complementary to the acceleration specifications used in conventional vibration testing. Just as the acceleration specification is the frequency spectrum envelope of the in-flight acceleration at the interface between the test item and flight mounting structure, the force limit is the envelope of the in-flight force at the interface . In force limited vibration tests, both the acceleration and force specifications are needed, and the force specification is generally based on and proportional to the acceleration specification. Therefore, force limiting does not compensate for errors in the development of the acceleration specification, e.g., too much conservatism or the lack thereof. These errors will carry over into the force specification. Since in-flight vibratory force data are scarce, force limits are often derived from coupled system analyses and impedance information obtained from measurements or finite element models (FEM). Fortunately, data on the interface forces between systems and components are now available from system acoustic and vibration tests of development test models and from a few flight experiments. Semi-empirical methods of predicting force limits are currently being developed on the basis of the limited flight and system test

  6. AUTOMATIC HAND COUNTER

    DOEpatents

    Mann J.R.; Wainwright, A.E.

    1963-06-11

    An automatic, personnel-operated, alpha-particle hand monitor is described which functions as a qualitative instrument to indicate to the person using it whether his hands are cold'' or hot.'' The monitor is activated by a push button and includes several capacitor-triggered thyratron tubes. Upon release of the push button, the monitor starts the counting of the radiation present on the hands of the person. If the count of the radiation exceeds a predetermined level within a predetermined time, then a capacitor will trigger a first thyratron tube to light a hot'' lamp. If, however, the count is below such level during this time period, another capacitor will fire a second thyratron to light a safe'' lamp. (AEC)

  7. Complex noninvasive spectrophotometry in examination of patients with vibration disease

    NASA Astrophysics Data System (ADS)

    Tchernyi, V. V.; Rogatkin, D. A.; Gorenkov, R. V.; Karpov, V. N.; Shumskiy, V. I.; Lubchenko, P. N.

    2006-02-01

    A lot of industry workers all over the world have dealings with a strong mechanical vibration as with daily technology processes. Very often such long-time professional vibration causes the so-called professional "vibration disease", in English literature "white fingers syndrome", caused by a local vibration of hands. Among different clinical features of the vibration disease a leader's part of them consists of different cardiovascular and trophic disorders of tissues. The objects of the present study were the peripheral blood microcirculation, peripheral blood oxygenation and tissues hypoxia state in a finger skin under vibration disease. For this purpose we have used a combined noninvasive spectrophotometry diagnostic technique consisting of Laser-Doppler Flowmetry (LDF), Laser Fluorescent Diagnostics (LFD) and Tissues Reflectance Oximetry (TRO). The results show good possibilities of all mentioned above diagnostic methods in estimation of different vascular disorders. A good correlation between persistent microcirculation disorders and trophic disturbances revealed in tissues of distal ends of upper extremities of the patients with vibration disease was estimated. Additionally, in present study with the use of real and long-time TRO and LDF methods a good correlation between LDF and TRO data including correlation in detected rhythms of blood microcirculation was estimated as well.

  8. Hands-on Universe

    NASA Astrophysics Data System (ADS)

    Oduori, Susan

    Science education in the 21st Century necessitates an introduction to the current and emerging tools and techniques of modern scientific research. We have recently launched a pilot, researchbased astronomy and astrophysics curriculum into Kenya High in Nairobi, Kenya as a vehicle to introducing the methodologies of scientific research into secondary education. Our program leverages global, web-accessible science education resources and connects to the online, international, science education community via the Global Hands-On Universe network. I describe the status and future plans of Hands-On Universe Africa.'

  9. American Association for Hand Surgery

    MedlinePlus

    ... Vargas Award Volunteer Scholarships Publications HAND Journal Hand Association News Research Annual Research Grant AAHS/PSF Combined ... Annual Meeting The annual meetings of the American Association for Hand Surgery, American Society for Peripheral Nerve, ...

  10. Three-Fingered Robot Hand

    NASA Technical Reports Server (NTRS)

    Ruoff, C. F.; Salisbury, J. K.

    1984-01-01

    Mechanical joints and tendons resemble human hand. Robot hand has three "human-like" fingers. "Thumb" at top. Rounded tips of fingers covered with resilient material provides high friction for griping. Hand potential as prosthesis for humans.

  11. Hand Washing: Do's and Dont's

    MedlinePlus

    ... to consumers. These products include liquid, foam and gel hand soaps, bar soaps and body washes. Alcohol- ... NN, et al. Revisiting the hand wipe versus gel rub debate: Is a higher-ethanol content hand ...

  12. Three-Fingered Robot Hand

    NASA Technical Reports Server (NTRS)

    Ruoff, C. F.; Salisbury, J. K.

    1984-01-01

    Mechanical joints and tendons resemble human hand. Robot hand has three "human-like" fingers. "Thumb" at top. Rounded tips of fingers covered with resilient material provides high friction for griping. Hand potential as prosthesis for humans.

  13. Are migratory behaviours of bats socially transmitted?

    PubMed Central

    Baerwald, E. F.; Barclay, R. M. R.

    2016-01-01

    To migrate, animals rely on endogenous, genetically inherited programmes, or socially transmitted information about routes and behaviours, or a combination of the two. In long-lived animals with extended parental care, as in bats, migration tends to be socially transmitted rather than endogenous. For a young bat to learn migration via social transmission, they would need to follow an experienced individual, most likely one roosting nearby. Therefore, we predicted that bats travelling together originate from the same place. It is also likely that young bats would follow their mothers or other kin, so we predicted that bats travelling together are more closely related to each other than bats not travelling together. To test our predictions, we used microsatellite genotypes and stable isotope values of δ13C, δ15N and δ2H to analyse the relatedness and geographical origins of migrating hoary bats (Lasiurus cinereus/Aeorestes cinereus (Baird et al. 2015 J. Mammal. 96, 1255–1274 (doi:10.1093/jmammal/gyv135)); n = 133) and silver-haired bats (Lasionycteris noctivagans; n = 87) killed at wind turbines over two consecutive autumn migrations. Contrary to our predictions, there was no evidence that related dyads of hoary bats or silver-haired bats were killed on the same night more frequently than expected by chance, or that the number of days between the fatalities of dyad members was influenced by relatedness or latitude of origin. Our data suggest that these bats do not socially transmit migration routes and behaviours among close kin. PMID:27152208

  14. Stochastic dynamics for reinfection by transmitted diseases

    NASA Astrophysics Data System (ADS)

    Barros, Alessandro S.; Pinho, Suani T. R.

    2017-06-01

    The use of stochastic models to study the dynamics of infectious diseases is an important tool to understand the epidemiological process. For several directly transmitted diseases, reinfection is a relevant process, which can be expressed by endogenous reactivation of the pathogen or by exogenous reinfection due to direct contact with an infected individual (with smaller reinfection rate σ β than infection rate β ). In this paper, we examine the stochastic susceptible, infected, recovered, infected (SIRI) model simulating the endogenous reactivation by a spontaneous reaction, while exogenous reinfection by a catalytic reaction. Analyzing the mean-field approximations of a site and pairs of sites, and Monte Carlo (MC) simulations for the particular case of exogenous reinfection, we obtained continuous phase transitions involving endemic, epidemic, and no transmission phases for the simple approach; the approach of pairs is better to describe the phase transition from endemic phase (susceptible, infected, susceptible (SIS)-like model) to epidemic phase (susceptible, infected, and removed or recovered (SIR)-like model) considering the comparison with MC results; the reinfection increases the peaks of outbreaks until the system reaches endemic phase. For the particular case of endogenous reactivation, the approach of pairs leads to a continuous phase transition from endemic phase (SIS-like model) to no transmission phase. Finally, there is no phase transition when both effects are taken into account. We hope the results of this study can be generalized for the susceptible, exposed, infected, and removed or recovered (SEIRIE) model, for which the state exposed (infected but not infectious), describing more realistically transmitted diseases such as tuberculosis. In future work, we also intend to investigate the effect of network topology on phase transitions when the SIRI model describes both transmitted diseases (σ <1 ) and social contagions (σ >1 ).

  15. Sexually transmitted diseases in Poland in 2011.

    PubMed

    Majewski, Sławomir; Rudnicka, Iwona

    2013-01-01

    Was to assess epidemiological situation of sexually transmitted diseases in Poland in 2011. Analysis of the data on prevalence of syphilis, gonorrhoea, non-gonococcal urethritis, genital herpes and genital warts was gathered from yearly reports MZ-14 from several didtricts. In 2011 there were 841 reported cases of all types of syphilis, which was higher by 24 than in 2010. Within the reported cases, 554 cases were of early syphilis, 274 cases of late syphilis, and 11 cases of congenital syphilis. Syphilis during pregnancy and childbirth was reported in 13 women. The highest incidence of syphilis in 2011, similarly to previous years was in Mazowieckie district (4.7/100,000) and the lowest in Swietokrzyskie district (0.2/100,000), the average in a whole country accounted to 2.2/100,000. In 2011 there were 351 cases of gonorrhoea reported, which was higher by 77 cases than reported in the previous year. The highest incidence was reported in Mazowieckie voivodeship. Non-gonococcal urethritis -NGU was identified in 484 persons; this was less by 294 cases than reported in the previous year. The highest incidence rate was reported in Dolnoślaskie voivodeship 9.6/100,000. There were 428 cases of genital warts reported which was less by 174 cases than reported in 2010. The highest incidence rate was reported in Mazowieckie voivodeship, Warminsko- Mazurskie voivodeship and Kujawsko-Pomorskie voivodeship. As in previous years the most unfavourable epidemiological situation in terms of all registered sexually transmitted diseases was in Mazowieckie voivodeship. In 2011 among sexually transmitted diseases NGU and genital warts were reported in lower numbers then in previous year. In the same time numbers of reported cases of gonorrhoea and syphilis increased. There is a continued decrease in the number of serological tests done for syphilis. Epidemiological indicators of treatment for gonorrhoea and syphilis are very low for number of years. The epidemiological data is

  16. Quantification of mouse in vivo whole-body vibration amplitude from motion-blur using x-ray imaging

    NASA Astrophysics Data System (ADS)

    Hu, Zhengyi; Welch, Ian; Yuan, Xunhua; Pollmann, Steven I.; Nikolov, Hristo N.; Holdsworth, David W.

    2015-08-01

    Musculoskeletal effects of whole-body vibration on animals and humans have become an intensely studied topic recently, due to the potential of applying this method as a non-pharmacological therapy for strengthening bones. It is relatively easy to quantify the transmission of whole-body mechanical vibration through the human skeletal system using accelerometers. However, this is not the case for small-animal pre-clinical studies because currently available accelerometers have a large mass, relative to the mass of the animals, which causes the accelerometers themselves to affect the way vibration is transmitted. Additionally, live animals do not typically remain motionless for long periods, unless they are anesthetized, and they are required to maintain a static standing posture during these studies. These challenges provide the motivation for the development of a method to quantify vibrational transmission in small animals. We present a novel imaging technique to quantify whole-body vibration transmission in small animals using 280 μm diameter tungsten carbide beads implanted into the hind limbs of mice. Employing time-exposure digital x-ray imaging, vibrational amplitude is quantified based on the blurring of the implanted beads caused by the vibrational motion. Our in vivo results have shown this technique is capable of measuring vibration amplitudes as small as 0.1 mm, with precision as small as  ±10 μm, allowing us to distinguish differences in the transmitted vibration at different locations on the hindlimbs of mice.

  17. Comparison of surgical hand scrub and alcohol surgical hand rub on reducing hand microbial burden.

    PubMed

    Ghorbani, Azam; Shahrokhi, Akram; Soltani, Zahra; Molapour, Azam; Shafikhani, Mahin

    2012-02-01

    This study was performed to compare the effects of two hand decontamination methods on the microbial burden of operating room staff hands. The surgical hand washing methods compared were a traditional surgical hand scrub using a povidone iodine solution, and a social wash using a liquid non-antibacterial soap followed by the application of an alcoholic hand rub.

  18. Self-screening for sexually transmitted infections.

    PubMed

    Potter, Yvonne

    2014-06-17

    There is an increasing trend towards self-collection of samples for sexually transmitted infection screening in lieu of genital examination and clinician-obtained urethral and cervical swabs. This article examines the advantages and disadvantages of this trend, and the effect on nursing practice particularly within integrated sexual health (ISH) services, which provide genito-urinary medicine (GUM) and contraceptive services. This article might also be of interest to nurses working within separate GUM and contraceptive services, especially those that are preparing to become ISH services.

  19. Preventing sexually transmitted infections: back to basics.

    PubMed

    Rompalo, Anne

    2011-12-01

    Sexually transmitted infections (STIs) have plagued humans for millennia and can result in chronic disease, pregnancy complications, infertility, and even death. Recent technological advances have led to a better understanding of the causative agents for these infections as well as aspects of their pathogenesis that might represent novel therapeutic targets. The articles in this Review Series provide excellent updates on the recent advances in understanding of the pathogenesis of some very important and persistent STIs and discuss the importance of considering each pathogen in the broader context of the environment of the individual who it infects.

  20. Optical smart packaging to reduce transmitted information.

    PubMed

    Cabezas, Luisa; Tebaldi, Myrian; Barrera, John Fredy; Bolognini, Néstor; Torroba, Roberto

    2012-01-02

    We demonstrate a smart image-packaging optical technique that uses what we believe is a new concept to save byte space when transmitting data. The technique supports a large set of images mapped into modulated speckle patterns. Then, they are multiplexed into a single package. This operation results in a substantial decreasing of the final amount of bytes of the package with respect to the amount resulting from the addition of the images without using the method. Besides, there are no requirements on the type of images to be processed. We present results that proof the potentiality of the technique.

  1. Rapid diagnosis of sexually transmitted infections.

    PubMed

    Otero-Guerra, Luis; Fernández-Blázquez, Ana; Vazquez, Fernando

    2017-02-23

    Sexually transmitted infections (STIs) are responsible for an enormous burden of morbidity and mortality. Worldwide, millions of cases of STIs, such as syphilis, chlamydia, or gonorrhoea occur every year, and there is now an increase in antimicrobial resistance in pathogens, such as gonococcus. Delay in diagnosis is one of the factors that justifies the difficulty in controlling these infections. Rapid diagnostic tests allow the introduction of aetiological treatment at the first visit, and also leads to treating symptomatic and asymptomatic patients more effectively, as well as to interrupt the epidemiological transmission chain without delay. The World Health Organisation includes these tests in its global strategy against STIs.

  2. Common sexually transmitted infections in adolescents.

    PubMed

    Gibson, Erica J; Bell, David L; Powerful, Sherine A

    2014-09-01

    Adolescents are often at higher risk for acquiring sexually transmitted infections (STIs). Medical providers should be alert for both asymptomatic and symptomatic STIs, and follow appropriate screening guidelines. Moreover, providers need to know how to best administer adolescent-friendly confidential care, treatment, and health education in the primary care setting. This article addresses the most common adolescent STIs and pertinent recommendations for screening, diagnosis, and management of infections, in addition to a brief focused discussion on human immunodeficiency virus and adolescents. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Hydrostatic limits of 11 pressure transmitting media

    NASA Astrophysics Data System (ADS)

    Klotz, S.; Chervin, J.-C.; Munsch, P.; LeMarchand, G.

    2009-04-01

    We present a systematic and comparative study of the pressure-induced solidification of 11 frequently used pressure transmitting fluids using the ruby fluorescence technique in a diamond anvil cell. These fluids are 1 : 1 and 5 : 1 iso-n pentane, 4 : 1 deuterated methanol-ethanol, 16 : 3 : 1 deuterated methanol-ethanol-water, 1 : 1 FC84-FC87 Fluorinert, Daphne 7474, silicone oil, as well as nitrogen, neon, argon and helium. The data provide practical guidelines for the use of these fluids in high pressure experiments up to 50 GPa.

  4. Drilling with fiber-transmitted, visible lasers

    SciTech Connect

    Kautz, D.D.; Berzins, L.V.; Dragon, E.P.; Werve, M.E.; Warner, B.E.

    1994-02-17

    High power and radiance copper-vapor laser technology developed at Lawrence Livermore National Laboratory shows great promise for many materials processing tasks. The authors recently transmitted the visible light produced by these lasers through fiber optics to perform hole drilling experiments. They found the tolerances on the hole circulatory and cylindricity to be excellent when compared to that produced by conventional optics. This technique lends itself to many applications that are difficult to perform when using conventional optics, including robotic manipulation and hole drilling in non-symmetric parts.

  5. Transmitting (and listening) may be good (or bad)

    NASA Astrophysics Data System (ADS)

    Penny, Alan

    2012-09-01

    Both listening and transmitting may, on an existential level, be either dangerous or beneficial. So we should ignore our irrational fears and listen in the hope of detecting ETI and transmit on the basis of promoting SETI activity.

  6. Design of power-transmitting shifts

    NASA Technical Reports Server (NTRS)

    Loewenthal, S. H.

    1984-01-01

    Power transmission shafting which is a vital element of all rotating machinery is discussed. Design methods, based on strength considerations for sizing shafts and axles to withstand both steady and fluctuating loads are summarized. The effects of combined bending, torsional, and axial loads are considered along with many application factors that are known to influence the fatigue strength of shafting materials. Methods are presented to account for variable amplitude loading histories and their influence on limited life designs. The influences of shaft rigidity, materials, and vibration on the design are discussed.

  7. Risks of acquiring and transmitting sexually transmitted diseases in sexual partner networks.

    PubMed

    Ghani, A C; Garnett, G P

    2000-11-01

    A person's risk for acquiring infection and their role in continued transmission has traditionally been assessed on the basis of individual characteristics. Recently, network studies have attempted to relate individual risks to position in the wider network. To assess the importance of local and global network structures in assessing the risk of acquiring and transmitting infection. An individual-based simulation model was used to construct a variety of potential network structures and track the transmission of infection over time. Logistic and Poisson regression were used to identify which measures of network position influence a person's risk for acquiring and transmitting infection. Measures of local centrality were more important to risk of acquisition, whereas global centrality mattered more to transmission. Continuous snowball sampling, rather than a fixed number of waves, better estimates a person's risks. There is an asymmetry regarding the risk of acquiring and transmitting infection.

  8. Force reflecting hand controller

    NASA Technical Reports Server (NTRS)

    Mcaffee, Douglas A. (Inventor); Snow, Edward R. (Inventor); Townsend, William T. (Inventor)

    1993-01-01

    A universal input device for interfacing a human operator with a slave machine such as a robot or the like includes a plurality of serially connected mechanical links extending from a base. A handgrip is connected to the mechanical links distal from the base such that a human operator may grasp the handgrip and control the position thereof relative to the base through the mechanical links. A plurality of rotary joints is arranged to connect the mechanical links together to provide at least three translational degrees of freedom and at least three rotational degrees of freedom of motion of the handgrip relative to the base. A cable and pulley assembly for each joint is connected to a corresponding motor for transmitting forces from the slave machine to the handgrip to provide kinesthetic feedback to the operator and for producing control signals that may be transmitted from the handgrip to the slave machine. The device gives excellent kinesthetic feedback, high-fidelity force/torque feedback, a kinematically simple structure, mechanically decoupled motion in all six degrees of freedom, and zero backlash. The device also has a much larger work envelope, greater stiffness and responsiveness, smaller stowage volume, and better overlap of the human operator's range of motion than previous designs.

  9. Current trends in hand surgery.

    PubMed

    Kalliainen, Loree K

    2012-06-01

    Hand surgery became an established subspecialty between World Wars I and II. Prior to this time, hand injuries were cared for by various specialists-neurosurgeons, plastic surgeons, orthopedic surgeons, and general surgeons-each of whom would focus on their particular tissue within the hand. With the nearly 90,000 hand injuries sustained during World War II, military hospitals were created to deal solely with hand injuries, and hand specialists began to treat the hand as a single functional organ. This article briefly reviews the origin of the field and discusses current trends in hand surgery.

  10. PC-based trending and analysis of floor vibration in sensitive fabrication areas

    NASA Astrophysics Data System (ADS)

    Palm, Jon E.; Middleton, Ben

    1992-02-01

    This paper describes a floor monitoring system utilizing a PC that continuously monitors very low levels of vibration and warns the user of possible " vibration contamination" that might result. The floor monitoring system designed by DataSignal Systems Inc. in Friendswood Texas is a complete package including special purpose microvelocity sensors signal conditioning and band specific velocity detection electronics analog-todigital sampling vibration spectrum analysis parameter trending alarming and archiving measurements. An IBM or compatible computer runs the systems software and displays the measured results. The computer can be installed in a convenient location for ease of use and maintenance. In order to maximize its effectiveness for alarms and ease of data display interpretation a VGA color monitor is a must. Since the system monitors facility vibration continuously the computer must be dedicated and not time shared. 2 . MEASURE MICRO-VIBRATION In many of todays high technology manufacturing facilities vibration can have a costly impact on the process and quality of an operation. This system can be set to alarm at vibration levels determined to be critical allowing an operator to take appropriate steps including date and time coding the process or even stopping the process. The system can also be used to establish limits for manufacturing operations in an adjoining facility that causes structure borne vibration to be transmitted to the vibration sensitive manufacturing area. Up to eight micro velocity sensor can be monitored simultaneously with results being displayed in a bar chart format on the computer screen. For detailed analysis purposes to help identify the source of vibration a narrowband FFT processor is used to display a vibration spectrum from a selected sensors output signal. The vibration spectrum analysis capability can be manually activated or be automatically acquired upon an alarm condition. 0819407577/92J$4. OO SPIE Vol. 1619 Vibration

  11. The influence of biodynamic factors on the mechanical impedance of the hand and arm.

    PubMed

    Burström, L

    1997-01-01

    The purpose of this study was to investigate the mechanical impedance of the human hand-arm system during exposure to random vibration under various experimental conditions and to evaluate statistically whether these experimental conditions have any influence on magnitude and phase of the mechanical impedance. A further aim was to compare the obtained results with other investigations where sinusoidal excitation has been used. The mechanical impedance was estimated in ten healthy subjects during exposure to random vibration, with a constant velocity spectrum within the frequency range 4-2000 Hz, by use of a specially designed laboratory handle. In the study, the influence of various conditions, such as vibration direction (Xh, Yh, Zh), grip force (25-75 N), feed force (20-60 N), frequency-weighted acceleration level (3, 6, 9, 12 m/s2) and hand and arm posture (five flexions, two abductions) were studied. The outcome showed that the vibration direction and the frequency of the vibration stimuli have a strong significant influence on the impedance of the hand. An increased vibration level resulted in a significantly lower impedance for frequencies over 100 Hz. Increase grip and feed forced led on the other hand to an increased impedance for all frequencies. With regard to hand and arm posture, the results show that the flexion and abduction had a significant contribution for frequencies below 30 Hz. Furthermore, the influence of some of the studied variables had a non-linear effect on the impedance but also differed between different exposure directions. It was concluded, moreover, that the vibration response characteristics of the hand and arm differ, depending whether the signal is a discrete frequency signal or a signal consisting of several frequencies.

  12. Hands-on Herps.

    ERIC Educational Resources Information Center

    Science Activities, 1987

    1987-01-01

    Presents a hands-on activity to help primary, intermediate, and advanced students learn about and compare the general characteristics of reptiles and amphibians. Suggests "herp stations" to provide experiences. Details materials, background and procedures necessary for using this activity. (CW)

  13. Arthritis of the Hand

    MedlinePlus

    ... If arthritis is due to damaged ligaments, the support structures of the joint may be unstable or “loose.” ... dominant hand is affected • Your personal goals, home support structure, and ability to understand the treatment and comply ...

  14. Why Firms Change Hands.

    ERIC Educational Resources Information Center

    Felder, Joseph

    1985-01-01

    Described is the subjective process by which the minimum asking price and the maximum offer prices are determined for a firm changing hands. Insight is gained into the meaning of fixed cost, opportunity cost, profit, present value, capital gain, and comparative advantages. (Author/RM)

  15. Learning "Hands On."

    ERIC Educational Resources Information Center

    Ritter, Janice T.

    2001-01-01

    Discusses a computer teacher's incorporation of hand-held computer technology into her third- and fifth-grade students' study of acid rain. The project successfully brought two grade levels together for cross-grade research, provided an opportunity for classroom teachers and technology specialists to work collaboratively, and enhanced students'…

  16. Hands-on Herps.

    ERIC Educational Resources Information Center

    Science Activities, 1987

    1987-01-01

    Presents a hands-on activity to help primary, intermediate, and advanced students learn about and compare the general characteristics of reptiles and amphibians. Suggests "herp stations" to provide experiences. Details materials, background and procedures necessary for using this activity. (CW)

  17. Rotationally Actuated Prosthetic Hand

    NASA Technical Reports Server (NTRS)

    Norton, William E.; Belcher, Jewell G., Jr.; Carden, James R.; Vest, Thomas W.

    1991-01-01

    Prosthetic hand attached to end of remaining part of forearm and to upper arm just above elbow. Pincerlike fingers pushed apart to degree depending on rotation of forearm. Simpler in design, simpler to operate, weighs less, and takes up less space.

  18. Hand-Eye Coordinations.

    ERIC Educational Resources Information Center

    Getman, G. N.

    1985-01-01

    The article describes ways in which visual-tactual integration develops in young children and explains reasons for some children's failure. Procedures for teaching basic writing skills such as hand position, grouping of letters, and finally the writing of words are discussed. (CL)

  19. Hands across the Border.

    ERIC Educational Resources Information Center

    Langston, Diane

    1990-01-01

    Describes the Hands across the Border Cultural Exchange Program between the communities of Palominas, Arizona, and Arizpe, Sonora, Mexico. An Arizona fifth/sixth grader studies Mexico prior to hosting a visitor from Mexico and enjoying a reciprocal visit to the Arizpe student's home. Highlights the program's unique features and benefits. (DMM)

  20. Hands-Only CPR

    MedlinePlus

    ... specific, especially if you’re calling from a mobile phone as that is not associated with a fixed address. Answering the dispatcher’s questions will not delay the arrival of ... save lives with Hands-Only CPR. Check out the Mobile Tour page to see if we're coming ...