| 1. |
- Barbieri, Dechristian Franca, et al.
(författare)
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Comparison of sedentary behaviors in office workers using sit-stand tables with and without semi-automated position changes
- 2017
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Ingår i: Human Factors. - : SAGE Publications. - 0018-7208 .- 1547-8181. ; 59:5, s. 782-795
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Tidskriftsartikel (refereegranskat)abstract
- Objective: This study compared usage patterns of two different electronically controlled sit-stand tables during a 2-month intervention period among office workers.Background: Office workers spend most of their working time sitting, which is likely detrimental to health. Although the introduction of sit-stand tables has been suggested as an effective intervention to decrease sitting time, limited evidence is available on usage patterns of sit-stand tables, and whether patterns are influenced by table configuration.Methods: Twelve workers were provided with standard sit-stand tables (non-automated table group) and 12 with semi-automated sit-stand tables programmed to change table position according to a pre-set pattern, if the user agreed to the system-generated prompt (semi-automated table group). Table position was monitored continuously for two months after introducing the tables, as a proxy for sit-stand behavior.Results: On average, the table was in a “sit” position for 85% of the work-day in both groups; this did not change significantly during the 2-month period. Switches in table position from sit to stand were, however, more frequent in the semi-automated table group than in the non-automated table group (0.65 vs. 0.29 hr-1; p=0.001).Conclusion: Introducing a semi-automated sit-stand table appeared to be an attractive alternative to a standard sit-stand table, since it led to more posture variation.Application: A semi-automated sit-stand table may effectively contribute to making postures more variable among office workers, and thus aid in alleviating negative health effects of extensive sitting.
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| 2. |
- Bianchi Piccinini, Giulio, 1982, et al.
(författare)
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How Do Drivers Respond to Silent Automation Failures? Driving Simulator Study and Comparison of Computational Driver Braking Models
- 2020
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Ingår i: Human Factors. - Chalmers University of Technology, Gothenburg, Sweden.; Volvo Group Trucks Technology, Gothenburg, Sweden.; Virginia Tech Transportation Institute, Blacksburg, USA.; University of Leeds, UK.; VTI, Gothenburg, Sweden. : SAGE Publications. - 1547-8181 .- 0018-7208. ; 62:7, s. 1212-1229
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Tidskriftsartikel (refereegranskat)abstract
- Objective: This paper aims to describe and test novel computational driver models, predicting drivers’ brake reaction times (BRTs) to different levels of lead vehicle braking, during driving with cruise control (CC) and during silent failures of adaptive cruise control (ACC). Background: Validated computational models predicting BRTs to silent failures of automation are lacking but are important for assessing the safety benefits of automated driving. Method: Two alternative models of driver response to silent ACC failures are proposed: a looming prediction model, assuming that drivers embody a generative model of ACC, and a lower gain model, assuming that drivers’ arousal decreases due to monitoring of the automated system. Predictions of BRTs issued by the models were tested using a driving simulator study. Results: The driving simulator study confirmed the predictions of the models: (a) BRTs were significantly shorter with an increase in kinematic criticality, both during driving with CC and during driving with ACC; (b) BRTs were significantly delayed when driving with ACC compared with driving with CC. However, the predicted BRTs were longer than the ones observed, entailing a fitting of the models to the data from the study. Conclusion: Both the looming prediction model and the lower gain model predict well the BRTs for the ACC driving condition. However, the looming prediction model has the advantage of being able to predict average BRTs using the exact same parameters as the model fitted to the CC driving data. Application: Knowledge resulting from this research can be helpful for assessing the safety benefits of automated driving.
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| 3. |
- Ciccarelli, Marina, et al.
(författare)
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Variation in Muscle Activity Among Office Workers When Using Different Information Technologies at Work and Away From Work
- 2013
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Ingår i: Human Factors. - : SAGE Publications. - 0018-7208 .- 1547-8181. ; 55:5, s. 911-923
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To determine differences in muscle activity amplitudes and variation of amplitudes, when using different Information and Communication Technologies (ICT).Background: Office workers use different ICT to perform tasks. Upper body musculoskeletal complaints are frequently reported by this occupational group. Increased muscle activity and insufficient muscle activity variation are potential risk factors for musculoskeletal complaints.Method: Muscle activity of right and left upper trapezius and right wrist extensor muscle bundle (extensor carpi radialis longus and brevis) of 24 office workers (performing their usual tasks requiring different ICT at work and away-from-work) were measured continuously over 10-12 hours. Muscle activity variation was quantified using two indices, APDF(90-10) and EVAsd.Results: There was a trend for electronics-based New ICT tasks to involve less electromyography (EMG) variation than paper-based Old ICT tasks. Performing Combined ICT tasks (i.e. using paper- and electronics-based ICT simultaneously) resulted in the highest muscle activity levels and least variation; however, these Combined ICT tasks were rarely performed. Tasks involving no ICT (Non-ICT) had the greatest muscle activity variation.Conclusion: Office workers in this study used various ICT during tasks at work and away-from-work. The high EMG amplitudes and low variation observed when using Combined ICT may present the greatest risk for musculoskeletal complaints, and use of Combined ICT by workers should be kept low in office work. Breaking up Combined, New and Old ICT tasks; for example, by interspersing highly variable Non-ICT tasks into office workers’ daily tasks, could increase overall muscle activity variation and reduce risk for musculoskeletal complaints.
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| 4. |
- Dahlman, Joakim, 1974-, et al.
(författare)
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Performance and Autonomic Responses during Motion Sickness
- 2009
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Ingår i: Human Factors. - : SAGE Publications. - 0018-7208 .- 1547-8181. ; 51:1, s. 56-66
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of the study was to investigate how motion sickness, triggered by an optokinetic drum, affects short term memory performance and to explore autonomic responses to perceived motion sickness. Background: Previous research has found motion sickness to decrease performance, but it is not known how short term memory in particular is affected. Method: Thirty-eight healthy participants performed a listening span test while seated in a rotating optokinetic drum. Measurements of motion sickness, performance, heart rate, skin conductance, blood volume pulse, and pupil size were performed simultaneously throughout the experiment. Results: A total of 16 participants terminated the trial due to severe nausea, while the other 22 endured the full 25 minutes. Perceived motion sickness increased over time in both groups, but less among those who endured the trial. Short term memory performance decreased towards the end for those who terminated, while it increased for the other group. Results from the measured autonomic responses were ambiguous. Conclusion: The present study concludes that performance, measured as short term memory, declines as perceived motion sickness progresses. Application: This research has potential implications for command and control personnel in risk of developing motion sickness.
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| 5. |
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| 6. |
- Duncan, Carolyn A., et al.
(författare)
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The Effect of Wave Motion Intensities on Performance in a Simulated Search and Rescue Task and the Concurrent Demands of Maintaining Balance
- 2022
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Ingår i: Human Factors. - : SAGE Publications. - 1547-8181 .- 0018-7208. ; 64:3, s. 579-588
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Tidskriftsartikel (refereegranskat)abstract
- Objective The purpose of this study was to examine how intensity of wave motions affects the performance of a simulated maritime search and rescue (SAR) task. Background Maritime SAR is a critical maritime occupation; however, the effect of wave motion intensity on worker performance is unknown. Methods Twenty-four participants (12 male, 12 female) performed a simulated search and rescue task on a six-degree-of-freedom motion platform in two conditions that differed in motion intensity (low and high). Task performance, electromyography (EMG), and number of compensatory steps taken by the individual were examined. Results As magnitude of simulated motion increased, performance in the SAR task decreased, and was accompanied by increases in lower limb muscle activation and number of steps taken. Conclusions Performance of an SAR task and balance control may be impeded by high-magnitude vessel motions. Application This research has the potential to be used by maritime engineers, occupational health and safety professionals, and ergonomists to improve worker safety and performance for SAR operators.
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| 7. |
- Engström, Johan A Skifs, 1973, et al.
(författare)
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Effects of working memory load and repeated scenario exposure on emergency braking performance
- 2010
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Ingår i: Human Factors. - : SAGE Publications. - 1547-8181 .- 0018-7208. ; 52:5, s. 551-559
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The objective of the present study was to examine the effect of working memory load on drivers' responses to a suddenly braking lead vehicle and whether this effect (if any) is moderated by repeated scenario exposure. Background: Several experimental studies have found delayed braking responses to lead vehicle braking events during concurrent performance of nonvisual, working memory-loading tasks, such as hands-free phone conversation. However, the common use of repeated, and hence somewhat expected, braking events may undermine the generalizability of these results to naturalistic, unexpected, emergency braking scenarios. Method: A critical lead vehicle braking scenario was implemented in a fixed-based simulator. The effects of working memory load and repeated scenario exposure on braking performance were examined. Results: Brake response time was decomposed into accelerator pedal release time and accelerator-to-brake pedal movement time. Accelerator pedal release times were strongly reduced with repeated scenario exposure and were delayed by working memory load with a small but significant amount (178 ms). The two factors did not interact. There were no effects on accelerator-to-brake pedal movement time. Conclusion:The results suggest that effects of working memory load on response performance obtained from repeated critical lead vehicle braking scenarios may be validly generalized to real world unexpected events. Application: The results have important implications for the interpretation of braking performance in experimental settings, in particular in the context of safety-related evaluation of in-vehicle information and communication technologies. © 2010, Human Factors and Ergonomics Society.
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| 8. |
- Eriksson, Lars, 1963-, et al.
(författare)
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Effects of visual flow display of flight maneuvers on perceived spatial orientation
- 2005
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Ingår i: Human Factors. - 0018-7208 .- 1547-8181. ; 47:2, s. 378-393
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Tidskriftsartikel (refereegranskat)abstract
- Postural responses were utilized as measures of the effectiveness of a wide-angle visual flow display in determining perceived spatial orientation (SO). The general experimental setup included a 150 degrees x 34 degrees wide-field display showing flight over computer-generated ground with horizon. Simulated roll maneuvers on this display induced postural sway in the observer that was registered by a head-tracker system. Two experiments with 16 participants in each investigated the effects of visual flow, display exclusions in the central visual field, and display extensions into the visual periphery. Clear vestibular and proprioceptive suppression effects were demonstrated on postural sway with the inclusion of visual flow of forward ego motion in roll maneuvers. Compared with the full view, up to 20 degrees x 20 degrees central field omission either did not reduce the effect or reduced the effect but, frequently, only moderately. Limiting the display area to 45 degrees in the horizontal dimension reduced display effectiveness significantly, whereas a 105 degrees area did not, compared with the full view. Utilizing postural responses as indications of visual display resonance with our SO mechanism, actual or potential applications of this research include the design of an interface integrating flight-adapted visual flow to counteract or reduce pilot spatial disorientation.
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| 9. |
- Friberg, Marc, et al.
(författare)
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The Effects of Stress on Tourniquet Application and CPR Performance in Layperson and Professional Civilian Populations
- 2023
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Ingår i: Human Factors. - : SAGE PUBLICATIONS INC. - 0018-7208 .- 1547-8181. ; 65:3, s. 496-507
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Tidskriftsartikel (refereegranskat)abstract
- Objective The purpose of this study was to compare laypeoples and professional first responders ability to perform tourniquet application and cardiopulmonary resuscitation (CPR) during calm and stressful circumstances. Background Life-threatening bleeding is a major cause of death that could be prevented by fast and appropriate first aid interventions. Therefore, laypeople are now being trained in bleeding control skills, transforming them from bystanders to immediate responders. However, critics have questioned whether laypeople are able to perform during more stressful conditions. Method Twenty-four laypersons and 31 professional first responders were tested in two conditions: a calm classroom scenario and a stressful scenario consisting of paintball fire and physical exertion. Stress and workload were assessed along with task performance. Results The experimental manipulation was successful in terms of eliciting stress reactions. Tourniquet application performance did not decline in the stressful condition, but some aspects of CPR performance did for both groups. First responders experienced higher task engagement and lower distress, worry and workload than the laypeople in both the calm and stressful conditions. Conclusion Stress did not affect first responders and laypeople differently in terms of performance effects. Stress should therefore not be considered a major obstacle for teaching bleeding control skills to laypeople. Application Tourniquet application can be taught to laypeople in a short amount of time, and they can perform this skill during stress in controlled settings. Concerns about laypeoples ability to perform under stress should not exclude bleeding control skills from first aid courses for civilian laypeople.
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| 10. |
- Gillespie, B. M., et al.
(författare)
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The Impact of Robotic-Assisted Surgery on Team Performance: A Systematic Mixed Studies Review
- 2021
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Ingår i: Human Factors. - : SAGE Publications. - 0018-7208. ; 63:8, s. 1352-1379
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Tidskriftsartikel (refereegranskat)abstract
- Objective The aim of this study is to describe the impact of robotic-assisted surgery on team performance in the operating room. Background The introduction of surgical robots has improved the technical performance of surgical procedures but has also contributed to unexpected interactions in surgical teams, leading to new types of errors. Method A systematic literature search of Cumulative Index to Nursing and Allied Health Literature, PubMed, ProQuest, Cochrane, Web of Science, PsycINFO, and Scopus databases using key words and MeSH terms was conducted. Screening identified studies employing qualitative and quantitative methods published between January 2000 and September 2019. Two reviewers independently appraised the methodological quality of the articles using theMixed Methods Appraisal Tool(2018). Discussions were held among authors to examine quality scores of the studies and emergent themes, and agreement was reached through consensus. Themes were derived using inductive content analysis. Results Combined searches identified 1,065 citations. Of these, 19 articles, 16 quantitative and 3 qualitative, were included. Robotic-assisted surgeries included urology, gynecology, cardiac, and general procedures involving surgeons, anesthetists, nurses, and technicians. Three themes emerged: Negotiating the altered physical environs and adapting team communications to manage task and technology; managing the robotic system to optimize workflow efficiency; andtechnical proficiency depends on experience, team familiarity, and case complexity. Conclusion Inclusion of a robot as a team member adds further complexity to the work of surgery. Application These review findings will inform training programs specifically designed to optimize teamwork, workflow efficiency, and learning needs.
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