| 1. |
- Hemphälä, Hillevi, et al.
(författare)
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A method for risk assessment within Visual Ergonomics
- 2015
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Ingår i: Proceedings of the 19th Triennial Congress of the International Ergonomics Association. ; , s. nr 1203-
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Konferensbidrag (refereegranskat)abstract
- IntroductionInsufficient visual ability can lead to increased work load and contribute to eyestrain and musculoskeletal discomfort, since “the eye leads the body” (Anshel, 2005). It has been shown that visually demanding work, such as computer work, is associated with eye discomfort, headaches and muscle pains in mainly the neck and shoulders (Rosenfield, 2011).Although the relation between eyestrain and musculoskeletal discomfort is not fully understood, studies have shown that straining the eyes increases the musculoskeletal activity in neck and shoulders (trapezius), and an association between visually demanding work, eye problems, headache and/or muscle problems have been found (Aarås et al., 2001; IESNA, 2011, Richter et al., 2008; Zetterberg et al., 2013). Problems due to insufficient visual ergonomics not only exist in computer intensive jobs, but in other professions as well. For example, surgeons and other surgical personnel that report eyestrain also report twice as much musculoskeletal discomfort from the upper part of the body (Hemphälä et al., 2011). In an intervention study among postmen, both eyestrain and musculoskeletal discomfort decreased after a visual ergonomic intervention. The intervention included providing customized eyeglasses and optimal lighting conditions (Hemphälä et al., 2012). Apart from health and well-being being affected by a poor visual ergonomic work environment, quality and productivity may also be reduced (Eklund, 2009).The aim of this paper is to present the first version of a practical, easy-to-use, and time-efficient risk assessment method for visual ergonomics. The development of the method including the evaluation will also be described. With such a method, risk factors within the visual environment can hopefully be detected, and interventions implemented in order to reduce the prevalence of symptoms related to poor visual ergonomics among workers.MethodsA first version of the method has been developed, mainly based on existing checklists and instruments (Colon et al. 1999; Børsting et al., 2008, Knave et al., 1985, Sheedy and Shaw-McMinn, 2002; Wilson & Corlett, 2005). During spring 2015, 30 ergonomists will be updated about visual ergonomics and introduced to the risk assessment method. Each ergonomist will thereafter use the method in 10 workplaces, yielding data and practical experiences from 300 risk assessments. These data will then be used to test the validity and reliability of the method, and if necessary to further develop it.ResultsThe first version of the risk assessment method for Visual Ergonomics will be presented at IEA 2015, together with results from the approximately 300 risk assessments made by the ergonomists. So far, the factors included in the method are objective measurements such as illuminance, luminance contrast, uniformity values, expert assessment of the risk for glare, and subjective ratings of the visual ability, eyestrain and musculoskeletal discomfort.DiscussionThe presented method will be compared to other similar methods. The used method for development will be discussed in relation to validity and reliability. Finally the presented risk assessment method will be discussed in relation to usefulness in prevention of discomfort and work related disorders at work places.
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| 2. |
- Malinovschi, Andrei, 1978-, et al.
(författare)
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Consequences of Using Post- or Prebronchodilator Reference Values in Interpreting Spirometry
- 2023
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Ingår i: American Journal of Respiratory and Critical Care Medicine. - : American Thoracic Society. - 1073-449X .- 1535-4970. ; 208:4, s. 461-471
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Tidskriftsartikel (refereegranskat)abstract
- RATIONALE: Post-bronchodilator (BD) spirometry is used for diagnosis of chronic obstructive pulmonary disease (COPD). However, pre-BD reference values are used for spirometry interpretation.OBJECTIVES: To compare the resulting prevalence rates of abnormal spirometry and study the consequences of using pre- or post-BD reference values generated within the Swedish CArdioPulmonary bioImage Study (SCAPIS) when interpreting post-BD spirometry in a general population.METHODS: SCAPIS reference values for post-BD and pre-BD spirometry were based on 10,156 and 1,498 never-smoking, healthy participants, respectively. We studied the associations of abnormal spirometry, defined by using pre- or post-BD reference values, with respiratory burden in the SCAPIS general population (28,851 individuals).MEASUREMENTS AND MAIN RESULTS: Bronchodilation resulted in higher predicted median and lower limit of normal (LLN) for FEV1/FVC ratio. The prevalence of post-BD FEV1/FVC < pre-bronchodilator LLN was 4.8% and that of post-BD FEV1/FVC < post-bronchodilator LLN was 9.9% for the general population. An additional 5.1% was identified as having an abnormal post-BD FEV1/FVC ratio and this group had more respiratory symptoms, emphysema (13.5% vs. 4.1%, p<0.001) and self-reported physician-diagnosed COPD (2.8% vs. 0.5%, p<0.001) than subjects with post-BD FEV1/FVC ratio > LLN for both pre- and post-bronchodilation).CONCLUSIONS: Pre- and post-bronchodilator spirometry reference values differ with regard to FEV1/FVC ratio. Use of post-bronchodilator reference values doubled the population prevalence of airflow obstruction; this was related to a higher respiratory burden. Using post-bronchodilator reference values when interpreting post-bronchodilator spirometry might enable identification of individuals with mild disease and be clinically relevant.
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| 3. |
- Parding, Karolina, et al.
(författare)
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Projekt: Nationell temagrupp A&O (arbetsplatslärande och omställning i arbetslivet)
- 2010
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Annan publikation (populärvet., debatt m.m.)abstract
- Europeiska Socialfondens temagrupp för arbetsplatslärande och omställning i arbetslivet som sammanställer, analyserar och sprider kunskaper och erfarenheter av hur långsiktig kompetensutveckling kan säkerställas på arbetsplatser i samarbete mellan arbetsgivare, fack, anställda, intermediärer, myndigheter och forskare.
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| 4. |
- Andersson, Per-Åke, 1945-
(författare)
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Multi-year maintenance optimisation for paved public roads - segment based modelling and price-directive decomposition
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- I avhandlingen studeras hur kostnadseffektiva underhålls- (uh-)planer för belagd väg kan genereras, på basis av information om aktuellt vägytetillstånd och funktionella modeller för kostnads- och tillståndsförändringar, delvis utvecklade i samarbete med svenska Vägverket (VV). Tilltänkt användning är på strategisk och programnivå, innan mer detaljerad objektinformation finns att tillgå. Till skillnad från hittills använda modeller, så genereras individuella uh-planer för varje vägsegment (en homogen vägsträcka vad gäller aktuellt beläggningstillstånd och beläggningshistorik), i kontinuerliga tillstånds- och åtgärdsrum. Genom användning av Lagrangerelaxerande optimeringsteknik, så kan de speciella nytto/kostnads-kvot-villkor som VV ålägger varje uh-objekt naturligen hanteras med dualpriser för budgetvillkoren. Antalet vägsegment som konkurrerar om budgetmedlen är vanligtvis stort. Data från VV:s Vägdatabank för Värmland har använts, omfattande ca 9000 vägsegment. Genom den stora datamängden har datorprogrammen implementerats för parallellbearbetning. Under avhandlingsarbetet har projektet beviljats tillgång till Monolith PCklustret vid NSC. För att kunna reducera optimeringskörtiderna har modell- och metodutveckling varit nödvändig. Genom att aggregera vägsegmenten till vägklasser har goda startvärden på dualpriserna erhållits. Genom utvecklingen av en speciell restvärdesrutin har den explicit behandlade tidsperioden kunnat reduceras. Vid lösandet av det duala subproblemet har speciell uppmärksamhet ägnats åt de diskretiseringseffekter som uppstår i metoden dynamisk programmering. En typ av tillämpning avser ett delvägnät, exempelvis en väg. Valideringsstudier har genomförts på väg 63 i Värmland – med lovande men inte tillfredsställande resultat (se nedan). En speciell modell för samordnat uh beaktar stordriftsfördelarna vid samtidig åtgärd på en hel vägsträcka. Den andra huvudtypen av studier gäller ett helt nätverk. Flera metodtyper har tillämpats, både för att lösa de relaxerade optimeringsproblemen och för att generera uhplaner som uppfyller budgetvillkoren. För en anständig diskretisering är körtiderna för hela Värmland mindre än 80 CPU-timmar. Genom en a posteriori primal heuristik reduceras kraven på parallellbearbetning till ett litet PC-kluster. Avhandlingen studerar vidare effekterna av omfördelade budgetmedel samt en övergång till en transparent, stokastisk modell – vilka båda visar små avvikelser från basmodellen.Optimeringsresultaten för Värmland indikerar att budgetnivåer på ca 40% av Värmlands verkliga uh-budget är tillräckliga. Dock saknas viktiga kostnadsdrivande faktorer i denna första modellomgång, exempelvis vissa funktionella prestanda (säkerhet), all miljöpåverkande prestanda (buller etc.) och strukturell prestanda (ex.vis bärighet, som enbart modelleras via ett åldersmått). För ökad tilltro till PMS i allmänhet och optimering i synnerhet, bör avvikelserna analyseras ytterligare och leda till förbättringar vad gäller tillståndsmätning, tillståndseffekt- & kostnadsmodellering samt matematisk modellering & implementering.
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| 5. |
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| 6. |
- Diaz Tartera, Hetzel O., et al.
(författare)
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Validation of SmartPill® wireless motility capsule for gastrointestinaltransit time : Intra-subject variability, software accuracy and comparison with video capsule endoscopy
- 2017
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Ingår i: Neurogastroenterology and Motility. - : Wiley. - 1350-1925 .- 1365-2982. ; 29:10
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: There is interest in ultimately combining endoscopy and motility assessments. Gastric emptying (GET), small bowel (SBTT), colon (CTT) and whole gut transit (WGTT) times are conveniently obtained by SmartPill® wireless motility capsule (WMC) that records luminal pH, temperature and pressure. Reproducibility within same subjects and accuracy of software derived times (MotiliGI® ) were investigated for diagnostic application. GET and SBTT were separately measured using video capsule endoscopy (VCE). The aim of this investigation was to assess same subject reproducibility of WMC, accuracy of software derived transit times and relate to Pillcam® SB (small bowel) VCE motility data.METHODS: Seventy three healthy adults ingested a 260 kcal mixed meal followed by WMC tests. Food intake was permitted after 6 hours. Regional transit data was obtained for GET, SBTT and CTT, the sum yielding WGTT. Nineteen subjects repeated WMC tests 2 or 4 weeks later; a separate 70 underwent VCE while fasted.KEY RESULTS: Visually derived data from WMC yielded GET 3.46±0.27, SBTT 5.15±0.21, CTT 20.76±1.19 and WGTT 29.53±1.28 hours (mean±SEM). Pearson's correlation coefficients (r) against software derived results were: GET 0.78 (P<.0001), SBTT 0.28 (P<.05), CTT 0.96 (P<.0001), WGTT 0.99 (P<.0001). VCE yielded lower GET (0.71±0.08 hours) and SBTT (4.15±0.13 hours).CONCLUSIONS AND INFERENCES: GET, SBTT, CTT and WGTT obtained by WMC are commensurate with literature values, including by other methods. Visually and software derived transit times have strongest correlations for CTT and WGTT. WMC yields longer GET and SBTT than VCE, perhaps due to meal related effects on motility.
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| 7. |
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| 8. |
- Glimne, Susanne, et al.
(författare)
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Headaches in combination with visual ability, eye- and musculoskeletal strain in connection with visually demanding work tasks
- 2022
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Konferensbidrag (refereegranskat)abstract
- Suboptimal visual ergonomics (i.e., the interaction between our vision, the light, the visual object, and the influence of other factors which impairs visibility) in work environment such as glare can cause headache in combination with eyestrain, visual ability, and musculoskeletal strain. Symptoms constituted to the syndrome of eyestrain has been well described among computer workers (see for example Han et al., 2013; Portello et al., 2012; Bhanderi et al., 2008; Mocci et al., 2001; Sanchez-Roman et al., 1996). However, research has not focused on investigating the presence of headaches associated with eye-related and musculoskeletal disorders among employees and visual related environmental factors.The purpose of presented research was to study the presence of headaches in combination with visual ability, eye- and musculoskeletal strain, and work ability in connection with visually demanding work. Trained assessors recruited study participants primarily from their regular clients in the OHS field. Evaluators were instructed to recruit participants with a variety of characteristics to ensure highly variable data, such as different work tasks, age, and gender. The participants mean age was 48.3 years (±10.3); 66% were women.A visual ergonomics risk assessment method (VERAM, Heiden et al. 2019; Zetterberg et al. 2017) was used to compile the participated workers subjective grading of headache, eye- and musculoskeletal strain using a questionnaire (n=430). At the same time, an evaluation of the visual environment was carried out, which established if there was a risk of glare associated with the implementation of work task (e.g., computer work and other related work such as industry, healthcare, and shipping industry). The frequency of headaches was divided into three categories; (1) no headache, (2) headache occasionally, and (3) headache a few times per week/almost every day. The measurements regarding evaluation of the visual environment used a photometer, an instrument which was available and that the assessors could use, usually a Hagner ScreenMaster or Hagner S1 / S2 / S3.About 65% of the workers reported headaches occasionally, a few times/week or almost every day. Among the workers with headaches reported about 29% of them that they experienced the headaches a few times/week or almost every day.Out of the workers with headaches reported 37% a severity of the headaches of more than 3 (on a scale of 1-10) and 5 % reported a severity of more than 6. About 40% of the workers also stated that the headaches affected their working ability. The headaches were mainly located around the eyes, forehead, or temples (70%) and came in the afternoon (69%). About 75% of the workers also reported that the headache disappeared or were reduced when they were off work for one night or over the weekend. The data collection showed that visual- related symptoms increased the higher the estimated headaches was.The musculoskeletal strain increased when the headache increased. When workers reported a high frequency of headaches 95% of them reported neck strain, 86% shoulder strain, 73% upper back strain, and 61% were reported arm strain.Moreover, only 8.2% of the workers rated their visual ability as bad or very bad, but at the same time, about 60% reported dim vision, 14% diplopia, and 59% problems changing focus at some time.Dividing the data into workers with experienced or unexperienced headaches this study has shown that there was a significant presence of headaches in combination with visual related symptoms regarding experienced photophobia (p=0.011), eye pain (p=0.015), diplopia (p=0.029), and arm strain (p=0.006). Further, the statistical analysis showed that there was a tendency of combination regarding headaches and visual ability (p=0.070).Dividing the data into workers with experienced or unexperienced headaches, our study showed that the frequency of headache increased due to high luminance levels within the visual field (p=0.044).This study concludes presence of headaches in combination with eye- and musculoskeletal strain performing work task such as computer work. Further, the presence of headaches is due to visual ability induced by high luminance levels within the visual field.
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| 9. |
- Heiden, Marina, 1974-, et al.
(författare)
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Validity of a computer-based risk assessment method for visual ergonomics
- 2019
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141 .- 1872-8219. ; 72, s. 180-187
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveTo describe the development of a computer-based risk assessment method for visual ergonomics, and assess its face validity, content validity, and internal consistency.MethodsThe risk assessment method contained a questionnaire for the worker, an evaluation form for the evaluator, a section of follow-up questions based on the worker's responses, and a section for recommended changes, including an overall risk assessment with respect to daylight, lighting, illuminance, glare, flicker, work space, work object and work postures, respectively. Forty-eight trained evaluators used the method to perform 224 workplace evaluations. Content validity of the method was assessed by the completeness and distribution of responses, and internal consistency was assessed by Cronbach's alpha, Spearman's rank correlation between items and indices, and exploratory factor analysis.ResultsThe proportion of missing values in items was generally low (questionnaire: 0–2.3%; evaluation form: 1.4–4.1%). In the questionnaire, items about double vision, migraine and corrective lenses had limited information content. Cronbach's alpha and item-index correlations for the indices frequency of eyestrain, intensity of eyestrain, visual symptoms, lighting conditions, frequency of musculoskeletal discomfort and intensity of musculoskeletal discomfort were satisfactory. Based on the factor analysis, suggestions for improving some of the indices were made.ConclusionOur findings suggest that this computer-based method is a valid instrument for assessing risks in the visual work environment. By incorporating subjective ratings by the worker as well as objective measurements of the work environment, it provides a good basis for recommendations with respect to daylight, lighting, work surfaces/material, and work object.Relevance to industryVisual environment factors, such as glare, can cause eyestrain, headache and musculoskeletal discomfort. This method satisfies the need of a valid tool for determining risks associated with the visual work environment. It contains both worker's ratings and objective measurements, and is designed to be used in different types of work.
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| 10. |
- Hemphälä, Hillevi, et al.
(författare)
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A method for assessing risks in visual ergonomics
- 2015
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Ingår i: Creating Sustainable Work-environments. - : NEHF. - 9788299574754 ; , s. B1-1-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- IntroductionA method for risk assessment in the field of visual ergonomics is under development. Insufficient visual ability can lead to increased workload and contribute to eyestrain and musculoskeletal discomfort. Although the relation between eyestrain and musculoskeletal discomfort is not fully understood, studies have shown that straining the eyes increases the musculoskeletal activity in the neck and shoulders (trapezius); associations between visually demanding work, eye problems, headaches and/or muscle problems have also been found (Aarås et al., 2001; IESNA, 2011; Zetterlund et al., 2009; Zetterberg et al., 2013; Toomingas et al., 2013; Richter et al., 2011; Richter et al., 2015). Problems due to insufficient visual ergonomics not only exist in computer intensive work, but in other professions as well, such as surgeons and postal workers (Hemphälä et al., 2011; Hemphälä et al.,2012).The aim of this project is to develop a practical, easy-to-use, and time efficient risk assessment method for visual ergonomics. With this method, risk factors in the visual environment can be detected, and interventions implemented to reduce the prevalence of symptoms related to poor visual ergonomics among workers.MethodsA first version of the risk assessment method has already been developed. In the spring of 2015, 27 ergonomists were taught visual ergonomics and introduced to the method. After the course, each ergonomist used the method to assess 8-10 workplaces, providing data and practical experiences from approximately 250 risk assessments. These data will be used to further develop and improve the method. During the fall of 2015 and spring of 2016, two other groups, each consisting of 30 ergonomists, will be trained in using the revised version of the risk assessment method in approximately 10 workplaces each. Data from these assessments will be used to test the validity and reliability of the method.ResultsThe first version of the risk assessment method for visual ergonomics will be presented at NES 2015 together with the results from the approximately 250 risk assessments made by the first group of ergonomists. So far, the factors included in the method are objective measurements of illuminance, luminance contrast, illuminance uniformity values, size of work object, visual angle; expert assessment of the risk for glare; and subjective ratings of visual ability, eyestrain and musculoskeletal discomfort. Some tendencies have been found of correlations between an objectively-rated high risk for glare and eyestrain/headache, as well as between a high contrast glare/luminance ratio and eyestrain.ConclusionSeveral factors in the visual environment contribute to wellbeing and the level of performance. In this risk assessment method for visual ergonomics, ergonomists have been trained to evaluate, for example, the risk for glare, as one of the major risks. The risk assessment method presented will be discussed in relation to its usefulness in the prevention of discomfort and work-related disorders at workplaces.
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