User experience with ultrawide curved displays: A mixed methods analysis

Due to the trend of replacing dual displays with ultrawide (UW) curved displays, we used a mixed methods analysis to investigate the user experience with UW curved displays. We conducted an experimental laboratory study that quantified user self-selected positions for three displays - 24 in. flat panel, and 34 in. and 40 in. UW curved displays. Participants were first provided with a familiarization protocol, and they then positioned the display. The self-selected UW display viewing distances were within current recommendations; however, viewing distance increased with display size, potentially challenging small work surface depths and may have been in response to feeling "overwhelmed" by larger displays. Head twist range of motion increased with display width. While all displays were within recommendations, participants commented that less head twisting was a factor in choosing the 34 in. over the 40 in. display. Practitioners should assess potential workstation limitations and the potential impact on neck twist angles when installing ultrawide displays.

Preventive use of eye drops to stabilize the tear film in video display terminal workers: preliminary notes

Abstract

In this work, he presents the results of preliminary work concerning the protective use of eye drops stabilizing all three layers that make up the tear film. Infact, video display terminals (VDT) are today an essential element in almost all work environments, from offices where they represent the fundamental work tool to production environments where they are indispensable for carrying out control functions (control stations, management of quantities and flows, etc.) or design. The risk due to VDTs is one of the factors considered by Legislative Decree 81/08, therefore its assessment falls within the employer's obligations and at the same time requires health surveillance by the occupational doctor.

Tear film changes in symptomatic versus asymptomatic video display terminal users following computer challenge test

PURPOSE

To assess the real-time changes in the tear film and ocular surface of symptomatic video display terminal (VDT) versus asymptomatic users.

METHODS

A total of 35 symptomatic (29 ± 5.6 years; Group 1, mild dry eye disease) and 35 asymptomatic (24.1 ± 4.6 years; Group 2) VDT users with a mean OSDI of 28 ± 11 and 0.86 ± 2.1, respectively, had tear film examination (Oculus Keratograph 5 M and Tearlab Osmolarity System) at baseline and after 1 h of watching a movie on the laptop inside a controlled environment chamber along with blink rate calculation.

RESULTS

The mean VDT use was 11.4 ± 3.2 h/day in Group 1 and 2.3 ± 2.3 h/day in Group 2. In Group 1, the mean pre- and post-VDT task values for NIBUT and bulbar congestion were 10.7 ± 3.7s and 6.7 ± 3.1s (P = 0.007), and 0.8 ± 0.4 and 1.1 ± 0.5 (P = 0.01), respectively. There were no significant changes in tear meniscus height (P = 0.77), Schirmer I (P =0.14), corneal staining score (P = 1.0), and tear osmolarity (P > 0.05). Group 2 showed insignificant change in all parameters. Only 16.2% individuals in Group 1 met modified TFOS-DEWS II diagnostic criteria at baseline that increased to 67.6% following VDT task. The blink rate reduced significantly during the last 15 min (6.8 ± 3.4 vs. 9.3 ± 4.5; P = 0.006) compared to the first 15 min of the task in Group 1, whereas no significant change occurred in Group 2.

CONCLUSION

Tear film instability and increased bulbar congestion are observed in symptomatic VDT users after computer work despite baseline stable tear film. The changes are significantly altered in symptomatic VDT users compared to asymptomatic users.

Video display terminal use and limitations according to italian legislative decree: occupational and forensic perspective

Abstract

In this paper, the authors conduct a review inherent in the use of video display units considering the laws currently in force in Italy, with emphasis on critical legislative and operational issues. Video Display Terminal (VDTs) are today an essential element in almost all work environments, from offices where they represent the fundamental work tool to production environments where they are indispensable for carrying out control functions (command stations, quantity management and flows, etc.) or for design work. The risk due to VDTs is one of the factors considered by the Italian Legislative Decree 81/08, so its assessment is part of the employer's obligations and at the same time requires health surveillance by the occupational physician. The new workstations have certainly not reduced visual postural demands, but they have changed them, opening the door to new disor-ders and imposing greater flexibility on the activity of the occupational physician, who often cannot limit himself to an annual inspection of the workplace. The aim of this work is to examine the current critical issues and future prospects of ergophthalmology.

A survey on the degree of eye discomfort caused by video terminal use among college students in different altitudes

OBJECTIVE

To analyze the risk factors associated with different levels of eye discomfort due to video terminal use among college students at different altitudes.

METHODS

This cross-sectional study was conducted to assess the prevalence and extent of eye discomfort by distributing an questionnaire to university students via the Internet. To analyze the causes and risk factors of eye discomfort among college students at different altitudes after using video terminals.

RESULTS

A total of 647 participants who met the criteria were included in this survey, of whom 292 (45.1%) were males and 355 (54.9%) were females. The results of the survey showed 194 (30.0%) participants without eye discomfort and 453 (70.0%) participants with eye discomfort. The results of the univariate comparison of the degree of eye discomfort in the study subjects with different characteristics showed that the differences in the degree of eye discomfort were statistically significant (P < 0.05) for the 7 groups of indicators: gender, region, wearing corneal contact lenses for more than 2 h per day, frequent use of eye drops, sleep time, total time of VDT use per day, and total time per VDT use, while the remaining indicators, including age, profession, and whether refractive surgery or other eye surgery was performed, whether frame glasses were worn for a long time, and duration of daily mask wear were not statistically significant. The results of multi-factor logistic analysis of the degree of eye discomfort in the study subjects with different characteristics showed that gender, region, frequent use of eye drops, sleep time, and total time of VDT use per day were the risk factors affecting the degree of eye discomfort.

CONCLUSIONS

Female, high altitude, frequent use of eye drops, shorter daily sleep duration and longer daily VDT use were associated risk factors for the development of severe eye discomfort, where the severity of eye discomfort was significantly negatively correlated with increased sleep duration and significantly positively correlated with increased total time of VDT use.

Eliciting blinks by transcutaneous electric nerve stimulation improves tear fluid in healthy video display terminal users: A self-controlled study

We aimed to elicit strong blinks among healthy video display terminal (VDT) users by periorbital transcutaneous electric nerve stimulation (TENS) and evaluate its impact on the tear fluid and visual task. Appropriate TENS conditions were evaluated to evoke strong blinks under minimum discomfort. Seventeen healthy VDT users with noninvasive Keratograph first breakup time (NIKf-BUT) 5-15 s and Ocular Surface Disease Index (OSDI) scores < 15 were recruited in this study. Before the trial, noninvasive Keratograph average breakup time (NIKa-BUT), tear meniscus height (TMH) and OSDI scores were evaluated. Before each TENS session, the volunteers played Tetris while the corresponding blink rate and Tetris scores were recorded. Then, the participants underwent 30 minutes of TENS, which evoked blinking of their right eye 20 times per minute. Tetris scores were evaluated again during TENS. The Tetris scores and corresponding blink rate were assessed after each TENS session while NIKa-BUT, TMH and OSDI scores were recorded after the third and sixth TENS sessions. We found that OSDI scores declined significantly after the sixth TENS (P = .003). The NIKa-BUT of the right eye was promoted after the sixth TENS (P = .02), and the TMH was higher after the third and sixth TENS in both eyes (P = .03, P = .03 for right eyes respectively, P = .01, P = .01 for left eyes respectively). There was no significant difference between the adjusted Tetris scores before and during TENS (P = .12). The blink rate before and after TENS were unaffected after 6 sessions (P = .61). The results indicated that periorbital TENS effectively ameliorated ocular irritation and improved tear secretion and tear film stability by eliciting strong blinks in healthy VDT users without disturbing the visual task.

Effects of a Traction Device for Head Weight Reduction and Neutral Alignment during Sedentary Visual Display Terminal (VDT) Work on Postural Alignment, Muscle Properties, Hemodynamics, Preference, and Working Memory Performance

The forward head posture of visual display terminal (VDT) users induces various physical and cognitive clinical symptoms. However, few studies have been conducted to identify and solve problems associated with VDT posture. This study aimed to examine the adverse effects of VDT posture and the positive effects of traction-combined workstations by measuring postural alignment, muscle properties, blood velocity, preference, and working memory. Thirty-four healthy VDT users (18 males and 16 females aged 20-30 years) participated in the experiment at three workstations, including conventional (VDT_C), head support (VDT_S), and upright (VDT_U) workstations. They conducted 2-back working memory task. The craniovertebral angle (CVA), muscle tone and stiffness, blood velocity and visual analogue discomfort scale (VADS) were measured to examine the influence of workstations. VDT_C showed increased muscle tone or stiffness in the levator scapulae (LS), suboccipital muscle (SM), and sternocleidomastoid muscle (SCM) and an increased reaction time (RT) in working memory. However, VDT_S showed decreased stiffness and tone of SM and improved comfort. In addition, VDT_U showed decreased stiffness or tone of the LS and SCM and improved blood velocity and RT. In conclusion, maintaining neutral alignment significantly improved working memory performance, muscle properties, and blood velocity.

Computer vision syndrome, musculoskeletal, and stress-related problems among visual display terminal users in Nepal

Background

The use of computers and other Visual Display Terminal (VDT) screens is increasing in Nepal. However, there is a paucity of evidence on the prevalence of Computer Vision Syndrome (CVS) and other occupational health concerns among employees working in front of VDT screens in the Nepalese population.

Objectives

This study aims to estimate the prevalence of CVS, musculoskeletal and work-related stress among VDT screen users in the office, as well as their understanding and usage of preventive measures.

Methods

The study was a cross-sectional descriptive study among 319 VDT users in office settings in Kathmandu Metropolitan City, Nepal, using a semi-structured self-administered questionnaire. Multivariate logistic regression analysis was conducted to identify the associated factors at 95% CI. P-value <0.05 was considered as statistically significant.

Results

The prevalence of CVS was 89.4%. More than eight out of ten study participants reported at least one visual and musculoskeletal symptom. Work-related stress, which was moderate-difficult to handle, was present in 36.7% of the study population. The mean±SD computer usage per day was 7.9±1.9 hours. Tired eye (63.3%), feeling of dry eye (57.8%), headache (56.9%) were the common visual symptoms of CVS reported. Total computer use/day > = 8 hours OR 2.6, improper viewing distance OR 3.2, Not using an anti-glare screen OR 2.6, not using eye-drops, and not wearing protective goggles OR 3.1 were significantly associated with the presence of CVS. There was no statistically significant association between visual symptoms of CVS, musculoskeletal symptoms, and stress with gender.

Conclusion

CVS was substantially related to not employing preventive measures, working longer hours, and having an incorrect viewing distance. With more hours per day spent in front of a VDT screen, work-related stress and musculoskeletal complaints were also found to be important correlates. Similarly, work-related stress was found more among those who had less than five years of job.

Investigation and Analysis of Eye Discomfort Caused by Video Display Terminal Use Among Medical Students Studying at High-Altitude Regions

Objective

To investigate the use of video display terminal (VDT) in high-altitude regions by medical students and the resulted risk factors of eye discomfort.

Methods

A cross-sectional study was conducted in 686 medical students randomly selected from high-altitude regions, Kunming, Yunnan Province. The prevalence of video display terminal syndrome (VDTs) and related risk factors in medical students were analyzed by instructing students to fill in the eye discomfort symptom questionnaire [Ocular Surface Disease Index (OSDI) scale].

Results

There were 686 participants in this study, including 213 males (31.0%) and 473 females (69.0%). The results of questionnaire survey showed that 184 patients (26.8%) didn't have eye discomfort symptoms and 502 patients (73.2%) had eye discomfort symptoms. The comparison of demographic and ocular characteristics of eye discomfort symptoms group and no eye discomfort symptoms group showed that medical students in the group with ocular discomfort symptoms had longer total duration of video terminal use, longer duration of each VDT use, higher total scores of ocular discomfort symptom scores, and a higher percentage of the ocular discomfort severity group, all with statistically significant differences. There was no significant difference in the remaining parameters between the two groups of participants. The results of multivariate logistic regression model analysis showed that the relationship between total sleep time, total duration of VDT use and eye discomfort symptom score was statistically significant (P < 0.05). Besides, ordinal logistic regression was applied further to investigate related factors of the severity of eye discomfort. The model demonstrated that total sleep duration and total VDT using duration were significantly associated with the severity of eye discomfort symptom (P < 0.05).The severity of eye discomfort symptom was significantly negatively related to the increased total sleep duration and it was significantly positively related to the increased VDT use duration.

Conclusion

The prevalence of VDTs is high in medical students at high-altitude regions. The longer total duration of daily use of VDT and shorter sleep duration are risk factors associated with VDTs. The severity of eye discomfort symptom was significantly negatively related to the increased total sleep duration and it was significantly positively related to the increased total VDT using duration.

Influence of Prolonged Visual Display Terminal Use on Physical and Mental Conditions among Health Care Workers at Tertiary Hospitals, Taiwan

This study aimed to examine the effects of prolonged VDT working time on physical and mental health disadvantages among health care workers (HCWs) in tertiary hospitals based on their work characteristics, age, and sex. Included in the study were 945 and 1868 participants in the non-doctor/nurse and doctor/nurse groups, respectively. The questionnaire included VDT usage-related information, the Nordic Musculoskeletal Questionnaire (NMQ), computer vision syndrome (CVS), perceived occupational stress, burnout, the Brief Symptom Rating Scale-5 (BSRS-5), and self-rated health (SRH). After adjustment, multiple logistical regression analysis revealed that the two groups showed that the longer the VDT working time, the higher the risk of muscle pain, severe headaches, severe job stress, and self-assessed bad sleep quality. This showed that the condition of the doctor/nurse group was more severe than that of the non-doctor/nurse group. According to the stratified analysis by sex and age, in the group of women under the age of 30, the adjusted odds ratio value of physical and mental conditions increased with longer VDT working time and was statistically significant. The result show that it is important to reduce daily VDT exposure for doctor, nurses, and women under 30.

Association of visual display terminal time with prevalence of temporomandibular disorder among Japanese workers

OBJECTIVES

Visual display terminal (VDT) time has been reported to affect the development of temporomandibular disorders (TMDs). However, no study has investigated the association between VDT time at and outside of work with TMDs Adjusting for known TMJ risk factors. This study aimed to investigate whether TMDs were associated with VDT time at and outside of work after adjusting for various working conditions in Japanese workers.

METHODS

This cross-sectional study was based on an internet survey of 3930 workers (2057 men and 1873 women), The TMD Screening Questionnaire (SQ-TMD), occupational factors, VDT time at and outside of work, psychosocial factors, and habits were assessed. We applied logistic regression to estimate the odds ratio (OR) of VDT time on SQ-TMD with adjustment for confounders.

RESULTS

The mean age of the respondents was 43.3 ± 11.7 years, and 778 (19.8%) and 3152 (80.2%) subjects were at high and low TMD-related symptoms (TRS). Logistic regression analysis adjusting for all covariates (Model 2), the prevalence of high TRS was significantly higher among those with VDT time at work of 60-179 min (OR = 1.52, 95% CI 1.18-1.94), 180-359 min (OR = 1.27, 95% CI 1.00-1.62), and more than 360 min (OR = 1.44, 95% CI 1.10-1.88) compared to those with 0-59 min. However, there was no significant difference in the prevalence of high TRS for VDT time outside of work.

CONCLUSION

VDT time at work, but not VDT time outside of work, influences the prevalence of TRS. Since the association between VDT time at work and the prevalence of TRS was found even after adjusting for sociopsychological factors and habits generally associated with TMD, further investigation of other factors is needed.

Influence of Reading on Smartphone Screens on Visual Optical Quality Metrics and Tear Film Stability

PURPOSE

To evaluate the impact of a prolonged reading session on a smartphone screen on optical quality metrics and tear film stability.

METHODS

This prospective study was conducted in 41 healthy volunteers who were asked to read an article on a smartphone screen for 20 minutes. The following tests were performed before the reading task in this consecutive order and repeated after the reading task in the same order: automated noninvasive tear break-up time, optical quality assessment including Objective Scatter Index (OSI), modulation transfer function, Strehl ratio, and tear film dynamic analysis as follows: vision break-up time (VBUT) as a function of OSI changes within 20 seconds, using a double-pass aberrometer imaging system, and fluorescein tear break-up time (FBUT) measured using the slit lamp.

RESULTS

All break-up time-related parameters (noninvasive tear break-up time, FBUT and VBUT) were significantly reduced after the reading task (P < 0.01). The OSI was significantly worsened after the reading task (P = 0.01), whereas all the other optical quality metrics (modulation transfer function and Strehl ratio) slightly deteriorated, were not statistically significant. A significant correlation was found between the shortening of the FBUT, VBUT, and the worsening of the OSI (r = -0.33, P < 0.05).

CONCLUSIONS

A reading session on a smartphone screen in healthy subjects was found to significantly affect the tear film stability and objectively worsen the retinal image quality.

Association of Visual Display Terminal Usage with Self-Rated Health and Psychological Distress among Japanese Office Workers during the COVID-19 Pandemic

The aim of this study was to examine the association of the duration of visual display terminal (VDT) usage for work and non-work activities with self-rated health (SRH) and psychological distress among office workers during the COVID-19 pandemic in Japan. A cross-sectional data of 7088 office workers from a web-based, self-administered survey conducted from 25 August 2020, to 30 September 2020, was used. Multiple logistic regression analysis was applied. Compared to those who used a VDT for 4–9 h for work, office workers who used a VDT for ≥10 h for work had poor SRH (odds ratio (OR): 1.65; 95% confidence interval (CI): 1.13, 2.41) and severe psychological distress (OR: 2.23; 95% CI: 1.52, 3.28). VDT usage for less than 1 h (OR: 1.37, 95% CI: 1.12, 1.67) and 1–3 h (OR: 1.42, 95% CI: 1.12, 1.80) for work were also associated with severe psychological distress. Stratification analysis by age showed a significant association of VDT usage for work with poor SRH among 30–64-year-olds, while a U-shape association was found between VDT usage for work and psychological distress with the younger age group (15–29 years old). During the COVID-19 pandemic in Japan, the prolonged usage of VDT for work can deteriorate both general and psychological health, while moderate usage of VDT for work can reduce psychological distress.

Effects of Mobile Computer Terminal Configuration and Level of Driving Control on Police Officers' Performance and Workload

OBJECTIVE

The objective of this study was to assess police officers' performance and workload in using two mobile computer terminal (MCT) configurations under operational and tactical driving conditions.

BACKGROUND

Crash reports have identified in-vehicle distraction to be a major cause of law enforcement vehicle crashes. The MCT has been found to be the most frequently used in-vehicle technology and the main source of police in-vehicle distraction.

METHOD

Twenty police officers participated in a driving simulator-based assessment of driving behavior, task completion time, and perceived workload with two MCT configurations under operational and tactical levels of driving.

RESULTS

The findings revealed that using the MCT configuration with speech-based data entry and head-up display location while driving improved driving performance, decreased task completion time, and reduced police officers' workload as compared to the current MCT configuration used by police departments. Officers had better driving but worse secondary task performance under the operational driving as compared to the tactical driving condition.

CONCLUSION

This study provided an empirical support for use of an enhanced MCT configuration in police vehicles to improve police officers' safety and performance. In addition, the findings emphasize the need for more training to improve officers' tactical driving skills and multitasking behavior.

APPLICATION

The findings provide guidelines for vehicle manufacturers, MCT developers, and police agencies to improve the design and implementation of MCTs in police vehicles considering input modality and display eccentricity, which are expected to increase officer and civilian safety.

Computer vision syndrome prevalence according to individual and video display terminal exposure characteristics in Spanish university students

AIM

To estimate the prevalence of computer vision syndrome (CVS) in university students and its relationship with sociodemographic and optical correction factors and exposure to video display terminal (VDT).

METHODS

This cross-sectional study included 244 Spanish university students who responded to an anamnesis, a VDT exposure questionnaire and the Computer Vision Syndrome Questionnaire (CVS-Q^© ). A descriptive analysis was performed and the prevalence of CVS was calculated. Logistic regression models were used to measure the association between CVS and the variables studied.

RESULTS

The mean age was 20.7 years (SD = 2.1), 57% were women, 78.3% used VDTs ≥ 2 hours/day to study. The prevalence of CVS was 76.6%, and the most frequent symptoms were headache and itching. In the crude analysis, being a woman, using glasses daily and to study, and a longer VDT use to study and in total were associated with a higher prevalence of CVS; while in the older group, the prevalence was lower. In the multivariate model, VDT use to study was associated with a greater probability of CVS (aOR: 3.43; 95%CI: 1.03-11.42), and being between 22 and 29 years was associated with a lower probability of it (aOR: 0.36; 95%CI: 0.15-0.89).

CONCLUSION

CVS has a high prevalence amongst Spanish university students. The most affected are the younger ones and those who use VDTs for longer hours to study. It is essential to continue investigating the influence of the type of tasks conducted with VDTs on CVS and thus to establish the preventive measures to reduce this syndrome.

Large-area display textiles integrated with functional systems

Displays are basic building blocks of modern electronics1,2. Integrating displays into textiles offers exciting opportunities for smart electronic textiles-the ultimate goal of wearable technology, poised to change the way in which we interact with electronic devices3-6. Display textiles serve to bridge human-machine interactions7-9, offering, for instance, a real-time communication tool for individuals with voice or speech difficulties. Electronic textiles capable of communicating10, sensing11,12 and supplying electricity13,14 have been reported previously. However, textiles with functional, large-area displays have not yet been achieved, because it is challenging to obtain small illuminating units that are both durable and easy to assemble over a wide area. Here we report a 6-metre-long, 25-centimetre-wide display textile containing 5 × 105 electroluminescent units spaced approximately 800 micrometres apart. Weaving conductive weft and luminescent warp fibres forms micrometre-scale electroluminescent units at the weft-warp contact points. The brightness between electroluminescent units deviates by less than 8 per cent and remains stable even when the textile is bent, stretched or pressed. Our display textile is flexible and breathable and withstands repeated machine-washing, making it suitable for practical applications. We show that an integrated textile system consisting of display, keyboard and power supply can serve as a communication tool, demonstrating the system's potential within the 'internet of things' in various areas, including healthcare. Our approach unifies the fabrication and function of electronic devices with textiles, and we expect that woven-fibre materials will shape the next generation of electronics.

Digital Screen Use and Dry Eye: A Review

Prolonged and continuous daily use of digital screens, or visual display terminals (VDTs), has become the norm in occupational, educational, and recreational settings. An increased global dependence on VDTs has led to a rise in associated visual complaints, including eye strain, ocular dryness, burning, blurred vision, and irritation, to name a few. The principal causes for VDT-associated visual discomfort are abnormalities with oculomotor/vergence systems and dry eye (DE). This review focuses on the latter, as advances in research have identified symptomology and ocular surface parameters that are shared between prolonged VDT users and DE, particularly the evaporative subtype. Several mechanisms have been implicated in VDT-associated DE, including blink anomalies, damaging light emission from modern devices, and inflammatory changes. The presence of preexisting DE has also been explored as an inciting and exacerbating factor. We review the associations between digital screens and DE, mechanisms of damage, and therapeutic options, hoping to raise awareness of this entity with the goal of reducing the global morbidity and economic impact of screen-associated visual disability.

Vaginal surgery: don't get bent out of shape

Vaginal hysterectomy rates in the United States are decreasing, despite it being the recommended hysterectomy route for benign hysterectomy by multiple societies. Visualization issues are a known barrier to a medical student learning in the operating room, and it is likely that this also extends to resident training. In addition, vaginal surgery can be taxing on both the surgeons and assistants, with high rates of musculoskeletal work disorders reported in vaginal surgeons. The use of a camera is integral to endoscopic surgery, and table-mounted retractor systems have been used for decades in open surgery. We bring these 2 features into vaginal surgery, that is, using a table-mounted camera system and a table-mounted vaginal retractor. When used together as demonstrated in this video, these tools can improve visualization and may improve ergonomics for the entire surgical team, including learners, during vaginal surgery.

Human factors in police mobile computer terminals: A systematic review and survey of recent literature, guideline formulation, and future research directions

The objectives of this research were to: (1) identify Mobile Computer Terminal (MCT) human factors issues, (2) formulate guidelines and an enhanced MCT for improving interface design and implementation in police patrols, and (3) identify areas of future research to fill gaps in the literature. A systematic literature search was conducted leading to results categorized in four groups including: productivity, physical discomfort, interface usability, and driving distraction. Although MCT use has increased officer productivity, several usability issues need to be resolved. The MCT has also increased officer physical discomfort and distraction. MCT design and implementation guidelines that resolve human factors issues in police patrols were identified along with an enhanced design concept. Guidelines for MCT design were validated with an online survey completed by 81 police officers. Future research directions were proposed to recognize police officer needs and work context.

Avatar-based versus conventional vital sign display in a central monitor for monitoring multiple patients: a multicenter computer-based laboratory study

BACKGROUND

Maintaining adequate situation awareness is crucial for patient safety. Previous studies found that the use of avatar-based monitoring (Visual Patient Technology) improved the perception of vital signs compared to conventional monitoring showing numerical and waveform data; and was further associated with a reduction of perceived workload. In this study, we aimed to evaluate the effectiveness of Visual Patient Technology on perceptive performance and perceived workload when monitoring multiple patients at the same time, such as in central station monitors in intensive care units or operating rooms.

METHODS

A prospective, within-subject, computer-based laboratory study was performed in two tertiary care hospitals in Switzerland in 2018. Thirty-eight physician and nurse anesthetists volunteered for the study. The participants were shown four different central monitor scenarios in sequence, where each scenario displayed two critical and four healthy patients simultaneously for 10 or 30 s. After each scenario, participants had to recall the vital signs of the critical patients. Perceived workload was assessed with the National Aeronautics and Space Administration Task-Load-Index (NASA TLX) questionnaire.

RESULTS

In the 10-s scenarios, the median number of remembered vital signs significantly improved from 7 to 11 using avatar-based versus conventional monitoring with a mean of differences of 4 vital signs, 95% confidence interval (CI) 2 to 6, p < 0.001. At the same time, the median NASA TLX scores were significantly lower for avatar-based monitoring (67 vs. 77) with a mean of differences of 6 points, 95% CI 0.5 to 11, p = 0.034. In the 30-s scenarios, vital sign perception and workload did not differ significantly.

CONCLUSIONS

In central monitor multiple patient monitoring, we found a significant improvement of vital sign perception and reduction of perceived workload using Visual Patient Technology, compared to conventional monitoring. The technology enabled improved assessment of patient status and may, thereby, help to increase situation awareness and enhance patient safety.

The need to accommodate monitor height changes between sitting and standing

Recently, the rate at which sit-to-stand workstations are being introduced into the workplace has seen a dramatic increase. Aside from adjusting the height of the desk when transitioning from sitting to standing, there is a lack of literature regarding the necessary adjustments to other equipment associated with the workstation. To better understand some of these limitations, 16 participants stood and sat at a sit-to-stand workstation while adhering to current Canadian Standards Association (CSA) Guidelines for Office Ergonomics. Transitioning between sitting and standing while adhering to CSA guidelines resulted in a 3.9 cm difference in monitor height relative to work surface between sitting and standing. Results from this investigation support the notion that monitor height adjustments relative to the work surface are necessary when utilising sit-to-stand workstations - with the implementation to practice message being that both sitting and standing configurations need to be assessed and accommodated in the workstation configuration. Practitioner summary: Limited guidelines exist in the necessary adjustments to equipment associated with sit-to-stand workstations. Transitioning between sitting and standing resulted in a 3.9 cm difference in monitor height relative to work surface between sitting and standing. This supports that monitor height adjustments relative to the workstation are necessary when using sit-to-stand workstations.

A novel approach to bi-objective optimization of touch-screen installation position for minimizing physical workload and increasing screen visibility

The aim of this study was to propose a new method for optimizing the touch-screen installation position in order to minimize the physical workload and increase screen visibility. Ten students participated in this study. The participants utilized a touch screen at different installation heights (50, 65, and 80% of stature), tilt angles (0°, 45°, and 90° from the horizontal plane), and having different button sizes (a square with a side of 10, 20, and 30 mm). The joint angles, when using a touch screen, were measured to calculate the joint torque ratios (JTRs). Subjective screen visibility were also determined. The optimal installation position was determined by solving a bi-objective optimization problem consisting of two objective functions. The Pareto optimal solutions for the two objectives showed a range of 1124-1251 mm and 44.4-67.9°. The proposed method determined the optimal installation position of the touch screens.

Determining the validity of the visual field principle for designing control/display arrangements

The Visual Field (VF) principle has been found to apply in many situations, but has not been tested under many possible conditions of operator posture with different display and control locations. In this research we used four display locations, four control locations relative to a seated operator and tested the strength of population stereotype for six different types of controls with linear displays moving either horizontally or vertically and circular displays with a neutral indicator at the 12, 3, 6 and 9 o'clock positions. Apart from several minor differences in operator responses, the VF principle held up well under all these different display/control relationships. By designing the display/control arrangement to have high stereotype strength, the direction of control movement for a given direction of indicator movement can be selected to comply with the VF principle for producing fewest errors in movement direction.

Trapezius muscle activity variation during computer work performed by individuals with and without neck-shoulder pain

This study aimed at determining the extent to which individuals with neck-shoulder pain and non-symptomatic individuals differ in muscle activation patterns, when performing computer work, as quantified by exposure variation analysis (EVA). As a secondary aim, we also aimed to quantify the day-to-day reliability of EVA variables describing trapezius muscle activation in a non-symptomatic control group. Thirteen touch-typing computer users (pain: n = 5, non-symptomatic: n = 8) completed three pre-selected computer tasks in the laboratory. Upper trapezius muscle activity was recorded using electromyography and analyzed using EVA with five amplitude and five duration categories. Individuals with neck-shoulder pain spent less time at low amplitudes and exhibited longer uninterrupted periods of muscle activation compared to their non-symptomatic counterparts. Thus, non-symptomatic workers tended to switch between exposure levels more often than individuals with pain. For a majority of EVA variables, ICCs ranged from 0.6 to 0.9, and between-days coefficients of variation were between 0.4 and 2.2.

Feel the noise: Mid-air ultrasound haptics as a novel human-vehicle interaction paradigm

Focussed ultrasound can be used to create the sensation of touch in mid-air. Combined with gestures, this can provide haptic feedback to guide users, thereby overcoming the lack of agency associated with pure gestural interfaces, and reducing the need for vision - it is therefore particularly apropos of the driving domain. In a counter-balanced 2 × 2 driving simulator study, a traditional in-vehicle touchscreen was compared with a virtual mid-air gestural interface, both with and without ultrasound haptics. Forty-eight experienced drivers (28 male, 20 female) undertook representative in-vehicle tasks - discrete target selections and continuous slider-bar manipulations - whilst driving. Results show that haptifying gestures with ultrasound was particularly effective in reducing visual demand (number of long glances and mean off-road glance time), and increasing performance (shortest interaction times, highest number of correct responses and least 'overshoots') associated with continuous tasks. In contrast, for discrete, target-selections, the touchscreen enabled the highest accuracy and quickest responses, particularly when combined with haptic feedback to guide interactions, although this also increased visual demand. Subjectively, the gesture interfaces invited higher ratings of arousal compared to the more familiar touch-surface technology, and participants indicated the lowest levels of workload (highest performance, lowest frustration) associated with the gesture-haptics interface. In addition, gestures were preferred by participants for continuous tasks. The study shows practical utility and clear potential for the use of haptified gestures in the automotive domain.

Determining fidelity of mixed prototypes: Effect of media and physical interaction

Mixed prototyping, combining virtual and physical prototypes, is an emerging method used to aid in usability testing. This study aims to determine when to use a mixed prototype and how to choose its fidelity to validate the usability testing results and reduce the prototyping cost. A 2×2 between-subject experiment was designed to investigate the effects of the media (head-mounted display versus computer monitor) and physical interaction (using a tangible mock-up or not) on the usability evaluation results and other subjective measures. The experiment results showed that, when aesthetic and functional features are controlled, the non-functional mock-up facilitates users in finding problems regarding physical interaction and ergonomics. Media with high immersion positively influenced the users' subjective ratings. Based on the findings of this study, guidelines on how to choose the fidelity of the prototype during different stages of a usability test are suggested to help product developers find a cost-efficient way to conduct usability tests.

Computer vision symptoms in people with and without neck pain

BACKGROUND

Sixty-four to 90% of computer users experience symptoms of computer vision syndrome (CVS). People with CVS symptoms experience neck pain (NP), and people with NP can have visual symptoms.

OBJECTIVES

(1) To examine differences in CVS symptoms in computer users with and without persistent NP. (2) To determine relationships between visual ergonomics, demographics, and CVS in those with and without persistent NP DESIGN: Comparative cross-sectional observational study METHOD: An online survey consisting of multiple questionnaires including the Computer Vision Syndrome Questionnaire (CVS-Q), Visual Symptoms Survey (VSS), and Convergence Insufficiency Symptoms Survey (CISS) was completed by 167 participants.

RESULTS

The persistent NP group had significantly higher CVS-Q, VSS, and CISS scores (p <0.01) compared to controls. No relationships were found between visual ergonomics, demographics, and visual symptoms in both groups.

CONCLUSIONS

People with persitent NP are more likely to present with CVS than controls. Clinicians should consider assessing visual symptoms in people presenting with persisting NP.

Detecting automation failures in a simulated supervisory control environment

The goal of this research was to determine how individuals perform and allocate their visual attention when monitoring multiple automated displays that differ in automation reliability. Ninety-six participants completed a simulated supervisory control task where each automated display had a different level of reliability (namely 70%, 85% and 95%). In addition, participants completed a high and low workload condition. The performance data revealed that (1) participants' failed to detect automation misses approximately 2.5 times more than automation false alarms, (2) participants' had worse automation failure detection in the high workload condition and (3) participant automation failure detection remained mostly static across reliability. The eye tracking data revealed that participants spread their attention relatively equally across all three of the automated displays for the duration of the experiment. Together, these data support a system-wide trust approach as the default position of an individual monitoring multiple automated displays. Practitioner Summary: Given the rapid growth of automation throughout the workforce, there is an immediate need to better understand how humans monitor multiple automated displays concurrently. The data in this experiment support a system-wide trust approach as the default position of an individual monitoring multiple automated displays. Abbreviations: DoD: Department of Defense; UA: unmanned aircraft; SCOUT: Supervisory Control Operations User Testbed; UAV: unmanned aerial vehicle; AOI: areas of interest.

Hydrogen-producing milk to prevent reduction in tear stability in persons using visual display terminals

PURPOSE

To examine the effect of hydrogen (H₂)-producing milk, which induces H₂ production by intestinal microbiota, on the prevention of dry eye disease.

METHODS

A randomized, double-blind, placebo-controlled, parallel-group comparative study was conducted in humans. Of 118 candidates aged 20-60 years who were using visual display terminals daily, 54 subjects (mean age, 42.4 years) with mild-to-moderate dry eye symptoms, who were not dry eye patients based on the 2006 Japanese Diagnostic Criteria for Dry Eye, were included in the study. Subjects were assigned to the H₂-producing milk group or the placebo group. They were instructed to ingest the assigned test beverage once per day for three consecutive weeks. Breath H₂ concentration, fluorescein tear film breakup time (fTBUT), Schirmer's test, 8-OHdG concentration in tears, reported ocular symptoms using the dry eye-related QOL score questionnaire, and the visual analogue scale were assessed at weeks 0 and 3.

RESULTS

Change in fTBUT in the H₂-producing milk group was significantly greater than that in the placebo group. A significant decline in fTBUT was observed in the placebo group (p = 0.04), but not the H₂-producing group (p = 0.26). This phenomenon was strongly observed in females. We found a positive correlation between the change in fTBUT and net H₂ production, and a negative correlation between the change in 8-OHdG concentration and net H₂ production in young females.

CONCLUSIONS

H₂-producing milk appeared to retard the decline in tear stability and may prevent short fTBUT-type dry eye by decreasing oxidative stress in the lacrimal functional unit.

User performance effects with graphical icons and training for elderly novice users: A case study on automatic teller machines

This study investigated the effects with training and graphical icons on task performance for elderly novice users on automatic teller machines (ATMs). 124 elderly novice users who had no prior ATM experience participated in the training and test of ATM usage. Participants in the control group (n = 62) were training to use the traditional text-based ATM interface meanwhile those in the experimental group (n = 62) were training to use the alternative ATM interface with graphical icons. They were asked to learn how to perform three major tasks of ATMs. A test immediately following the training and a test one month after training was carried out. Task completion score was used for measuring user performance. The results showed although training could help elderly novice users succeed in learning to use ATMs, they still had a significant decline in user performance in the test one month later compared with the immediate test. Participants of the experimental group outperformed those of the control group in both the immediate test and one month test after training, especially in the latter. The finding suggested graphical icons could help to improve the learning and retention of ATM usage for elderly novice users, especially the latter, which would compensate for the drawback of training and reduce forgetting rate to some extent. Well-designed graphical icons could benefit elderly novice users much from learning phase to retention phase. The findings of this study can be applied to guide the design and development of ATMs or other public technology devices considering elderly novice users.

Effects of display curvature and task duration on proofreading performance, visual discomfort, visual fatigue, mental workload, and user satisfaction

This study examined the effects of display curvature and task duration on proofreading performance, visual discomfort, visual fatigue, mental workload, and user satisfaction. Five 27″ rear-screen mock-ups with distinct curvature radii (600R, 1140R, 2000R, 4000R, and flat) were used. Ten individuals per display curvature completed a series of four 15 min comparison-proofreading trials at a 600 mm viewing distance. Only proofreading speed benefited from display curvature, with 600R providing the highest mean proofreading speed. Proofreading speed increased and accuracy decreased for all display curvatures over the 1 h proofreading period. Visual discomfort, visual fatigue, and mental workload increased during the first 15 min of proofreading. A decrease in critical fusion frequency during that period indicated increases in visual fatigue and mental workload. A short break between 15 min proofreading tasks could be considered to prevent further degradation of task performance and ocular health.

Accommodative asthenopia among Romanian computer-using medical students-A neglected occupational disease

Computers have become to play an important role in people's lives throughout the world thus increasing the number of patients with ocular complaints. Also known as computer vision syndrome, accommodative asthenopia might be considered as a neglected occupational condition, but there is no consensus regarding diagnostic criteria, which leads to under-recognition and under-reporting. The aim of the study was to investigate the prevalence, early symptoms and specific preventive measures of accommodative asthenopia among computer-using medical students (n = 420), in a cross-sectional study. The most common early symptoms were: tired eyes/eye strain (86.1%), burning eyes (46.8%), migraines/headaches (46.8%), red-swollen eyes (43%), photophobia (41.8%), temporary blurred vision (35.4%), and eyelid spasms (32.9%). Our study identifies the most frequent early symptoms of accommodative asthenopia as a possible occupational disease, which might serve as a fundament for a future consensus strategy.

Eye-tracking for assessing medical image interpretation: A pilot feasibility study comparing novice vs expert cardiologists

INTRODUCTION

As specialized medical professionals such as radiologists, pathologists, and cardiologists gain education and experience, their diagnostic efficiency and accuracy change, and they show altered eye movement patterns during medical image interpretation. Existing research in this area is limited to interpretation of static medical images, such as digitized whole slide biopsies, making it difficult to understand how expertise development might manifest during dynamic image interpretation, such as with angiograms or volumetric scans.

METHODS

A two-group (novice, expert) comparative pilot study examined the feasibility and utility of tracking and interpreting eye movement patterns while cardiologists viewed video-based coronary angiograms. A non-invasive eye tracking system recorded cardiologists' (n = 8) visual behaviour while they viewed and diagnosed a series of eight angiogram videos. Analyses assessed frame-by-frame video navigation behaviour, eye fixation behaviour, and resulting diagnostic decision making.

RESULTS

Relative to novices, expert cardiologists demonstrated shorter and less variable video review times, fewer eye fixations and saccadic eye movements, and less time spent paused on individual video frames. Novices showed repeated eye fixations on critical image frames and regions, though these were not predictive of accurate diagnostic decisions.

DISCUSSION

These preliminary results demonstrate interpretive decision errors among novices, suggesting they identify and process critical diagnostic features, but sometimes fail to accurately interpret those features. Results also showcase the feasibility of tracking and understanding eye movements during video-based coronary angiogram interpretation and suggest that eye tracking may be valuable for informing assessments of competency progression during medical education and training.

Are touch screen technologies more effective than traditional educational methods in children with autism spectrum disorders? A pilot study

Applied Computer technologies can address the needs of individuals with autism spectrum disorders (ASD). Data on the efficacy of assistive technology in ASD is limited, and its effectiveness in supporting and facilitating skill acquisition in this specific population must be still demonstrated. 63 Italian ASD subjects underwent learning activities administered by cardboards or a touch screen support. The support preference was evaluated in a choice trial, and quantitative analysis was performed on items regarding communication and challenging behaviours. Touch devices are attractive especially for males without intellectual disability and a lower communication and cooperation behaviours with the use of touch screen compared with paper support was shown depending on activities. Overall, our data do not confirm the hypothesis that touch screen presentation improves activity completion and behavioural performance for each individual with ASD. Data discourage an indiscriminate use of these devices and suggest analysing with more attention the core ingredients that should shape digital devices when used for people on ASD.

Effects of Display Curvature, Presbyopia, and Task Duration on Visual Fatigue, Task Performance, and User Satisfaction

OBJECTIVE

This study examined the effects of display curvature, presbyopia, and task duration on visual fatigue, task performance, and user satisfaction.

BACKGROUND

Although curved displays have been applied to diverse display products, and some studies reported their benefits, it is still unknown whether the effects of display curvature are presbyopia-specific.

METHOD

Each of 64 individuals (eight nonpresbyopes and eight presbyopes per display curvature) performed four 15-min proofreading tasks at one display curvature radius setting (600R, 1140R, 4000R, and flat; mm). Diverse measurements were obtained to assess visual fatigue, task performance, and user satisfaction.

RESULTS

The mean pupil diameter was the largest with 1140R, indicating this curvature radius was associated with the least development of visual fatigue; 600R was comparable with 1140R in terms of pupil diameter. The presbyopic group showed a 28.5% slower proofreading speed compared with the nonpresbyopic group, whereas their proofreading accuracy was comparable. For both groups, the mean visual fatigue increased significantly during the first 15 min of proofreading, as indicated by a decrease of 0.11 mm in the mean pupil diameter, an increase of 3.8 in the mean bulbar conjunctival redness, and an increase of 9.13 in the mean eye complaint questionnaire score.

CONCLUSION

The effect of display curvature was not presbyopia-specific. Low visual fatigue was observed with 1140R and 600R.

APPLICATION

Display curvature radii near or in the range of 600R and 1140R and frequent breaks are recommended for both presbyopic and nonpresbyopic groups to reduce their visual fatigue due to visual display terminal tasks.

Future technology on the flight deck: assessing the use of touchscreens in vibration environments

Use of touchscreens in the flight deck has been steadily increasing, however, their usability may be severely impacted when turbulent conditions arise. Most previous research focusses on using touchscreens in static conditions; therefore, this study assessed touchscreen use whilst undergoing turbulent representative motion, generated using a 6-axis motion simulator. Touchscreens were tested in centre, side and overhead positions, to investigate how turbulence affected: (1) error rate, movement times and accuracy, (2) arm fatigue and discomfort. Two touchscreen technologies were compared: a 15" infra-red and a 17.3" projected capacitive touchscreen with force sensing capability. The potential of the force sensing capability to minimise unintentional interactions was also investigated. Twenty-six participants undertook multi-direction tapping (ISO 9241; ISO 2010 ) and gesture tasks, under four vibration conditions (control, light chop, light turbulence and moderate turbulence). Error rate, movement time and workload increased and usability decreased significantly, with screen position and increasing turbulence level. Practitioner Summary: This study evaluated the use of infra-red and projected capacitive touchscreen technologies using multi-directional tapping and gesture tasks, whilst being subjected to different levels of turbulence representative motion. Performance degraded significantly with increasing turbulence level and touchscreen location. This has implications for future flight deck design.

Mammography cancer detection: comparison of single 8MP and pair of 5MP reporting monitors

OBJECTIVE:

To compare breast cancer detection using a single 8MP display with using a standard pair of 5MP monitors.

METHODS:

An observer study was carried out in which mammograms were read using full field views only, and again with the additional use of magnified quadrant views. Seven observers read 300 cases, one view per breast, using each display type. Cases comprised 100 normal cases and 200 cases with cancers of subtle or very subtle appearance: 100 with malignant calcification clusters and 100 with non-calcified lesions. JAFROC software was used to analyse the results.

RESULTS:

When mammograms were viewed full field only, observers performed better (p = 0.050) in detecting malignant calcification clusters when using the pair of 5MP monitors compared with a single 8MP monitor. This result became non-significant when results were generalised to a population of readers. Performance in detecting calcification clusters was improved by using quadrant view in addition to full field view when using either the pair of 5MP monitors or the 8MP monitor. There was no significant difference in detection of all types of cancer between the pair of 5MP monitors and the 8MP monitor when quadrant zoom was used.

CONCLUSION:

Providing quadrant view is used in addition to full field view, there is no significant difference in cancer detection between the 8MP monitor and the pair of 5MP monitors.

ADVANCES IN KNOWLEDGE:

Effect of magnification on the detectability of subtle malignant calcification clusters in breast screening.

Effects of unexpected visual motion on postural sway and motion sickness

Motion sickness is thought to occur when the brain's assumptions about incoming sensory information do not match the actual signals received. These signals must involve the vestibular system for motion sickness to occur. In this paper, we describe an experiment in which subjects experienced unexpected visual motions, or perturbations, as they navigated a virtual environment (VE) while standing and wearing a head mounted display (HMD) or while viewing a monitor. We found that postural instability, as measured by a balance board, increased with time only when perturbations were present. HMD users exhibited greater sway when exposed to visual perturbations than did monitor users. Yet motion sickness increased only when an HMD was used and occurred with or without participants undergoing perturbations. These results suggest that the postural instability which is generated by unexpected visual perturbation does not necessarily increase the likelihood of motion sickness in a virtual environment.

Effect of Heat-Killed Lactobacillus paracasei KW3110 Ingestion on Ocular Disorders Caused by Visual Display Terminal (VDT) Loads: A Randomized, Double-Blind, Placebo-Controlled Parallel-Group Study

BACKGROUND

Visual display terminals (VDTs) emitting blue light can cause ocular disorders including eye fatigue. Some dietary constituents have been reported to be effective in improving ocular disorders while few clinical studies have been performed. We evaluated the effects of heat-killed Lactobacillus paracasei KW 3110 on improving ocular disorders and symptoms of eye fatigue among healthy human subjects with VDT loads.

METHODS

In vitro, the effect of L. paracasei KW3110 on blue light-induced human retinal pigment epithelial (ARPE-19) cell damage. For clinical studies, 62 healthy Japanese volunteers of 35 to 45 years of age who had experienced eye fatigue were randomized into two groups and given a placebo or L. paracasei KW3110-containing supplements for eight weeks. The primary endpoint was changes in VDT load-induced eye fatigue as determined by critical flicker frequency four and eight weeks after the start of supplementation.

RESULTS

In vitro, blue light-induced human retinal cell death was suppressed with the culture supernatants of cells treated with L. paracasei KW3110. In clinical study, the VDT load-induced reduction of critical flicker frequency tended to be milder in the L. paracasei KW3110 group when compared with the placebo group during the fourth week. Subgroup analysis classified by the degree of eye fatigue showed that the VDT load-induced reduction of critical flicker frequency was significantly better in the high-level eye fatigue subjects from the L. paracasei KW3110 group when compared with the placebo group during the fourth week (p = 0.020).

CONCLUSIONS

L. paracasei KW3110 suppressed blue light-induced retinal pigment epithelial cell death. In the clinical study, ingestion of L. paracasei KW3110 had a potential to improve eye fatigue induced by VDT loads especially high levels of eye fatigue. However, further studies should be required to show more dependable clinical efficacy of L. paracasei KW3110.

Simulation-based evaluation of an in-vehicle smart situation awareness enhancement system

Situation awareness (SA) constitutes a critical factor in road safety, strongly related to accidents. This paper describes the evaluation of a proposed SA enhancement system (SAES) that exploits augmented reality through a head-up display (HUD). Two SAES designs were evaluation (information rich vs. minimal information) using a custom-made simulator and the Situation Awareness Global Assessment Technique with performance and EEG measures. The paper describes the process of assessing the SA of drivers using the SAES, through a series of experiments with participants in a Cave Automatic Virtual Environment. The effectiveness of the SAES was tested in a within-group research design. The results showed that the information rich (radar-style display) was superior to the minimal (arrow hazard indicator) design and that both SAES improved drivers' SA and performance compared to the control (no HUD) design. Practitioner Summary: Even though driver situation awareness is considered as one of the leading causes of road accidents, little has been done to enhance it. The current study demonstrates the positive effect of a proposed situation awareness enhancement system on driver situation awareness, through an experiment using virtual prototyping in a simulator.

Individual and work-related risk factors for musculoskeletal pain among computer workers in Nigeria

We investigated the prevalence of musculoskeletal pain (MSP) and the association of 1-month prevalence with individual and work-related factors among commercial typists in Enugu. Participants responded to a questionnaire about occurrences of MSP and a 75.6% (242/320) response rate was achieved. Prevalence was summarized in frequencies and percentages while associations between MSPs and risk factors were explored using chi-square. MSP was most common in the low back (58.3%), and low back pain limited 51.7% from activities between 1 and 30 days. Advancing age was significantly associated with MSP in the low back (x² = 19.885; p = .001), neck (x² = 28.309; p < .001), shoulder (x² = 13.122; p = .011), but not wrist/hand (p = .075). Working 1-5 years in this job was associated with increasing prevalence of MSP in all body regions studied. Lesser job control was associated with increased prevalence of wrist/hand pain. Prevalence of MSDs among computer operators in Enugu, Nigeria, is high and highlights the importance of workplace intervention.

The effect of parallax on eye fixation parameter in projection-based stereoscopic displays

The promising technology of stereoscopic displays is interesting to explore because 3D virtual applications are widely known. Thus, this study investigated the effect of parallax on eye fixation in stereoscopic displays. The experiment was conducted in three different levels of parallax, in which virtual balls were projected at the screen, at 20 cm and 50 cm in front the screen. The two important findings of this study are that parallax has significant effects on fixation duration, time to first fixation, number of fixations, and accuracy. The participant had more accurate fixations, fewer fixations, shorter fixation durations, and shorter times to first fixation when the virtual ball was projected at the screen than when it was projected at the other two levels of parallax.

Is the Type of Vdt Work Important in Asthenopia?

The Authors studied the relationship between visual fatigue (or asthenopia) and different types of work with display units on about 30,000 videoterminal (VDT) operators of the Italian telecommunication company. Visual fatigue was reported with data entry, data checking, word processing, dialogue enquiry, and various services. The Chi-square test showed that asthenopia was not related to any particular type of VDT work, comparing subjects working at the VDT for similar times each week. These findings provide further confirmation that the main factor determining visual fatigue in VDT operators is the amount of time spent at the display units.

Optical correction of refractive error for preventing and treating eye symptoms in computer users

BACKGROUND

Computer users frequently complain about problems with seeing and functioning of the eyes. Asthenopia is a term generally used to describe symptoms related to (prolonged) use of the eyes like ocular fatigue, headache, pain or aching around the eyes, and burning and itchiness of the eyelids. The prevalence of asthenopia during or after work on a computer ranges from 46.3% to 68.5%. Uncorrected or under-corrected refractive error can contribute to the development of asthenopia. A refractive error is an error in the focusing of light by the eye and can lead to reduced visual acuity. There are various possibilities for optical correction of refractive errors including eyeglasses, contact lenses and refractive surgery.

OBJECTIVES

To examine the evidence on the effectiveness, safety and applicability of optical correction of refractive error for reducing and preventing eye symptoms in computer users.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; Embase; Web of Science; and OSH update, all to 20 December 2017. Additionally, we searched trial registries and checked references of included studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-randomised trials of interventions evaluating optical correction for computer workers with refractive error for preventing or treating asthenopia and their effect on health related quality of life.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility and risk of bias, and extracted data. Where appropriate, we combined studies in a meta-analysis.

MAIN RESULTS

We included eight studies with 381 participants. Three were parallel group RCTs, three were cross-over RCTs and two were quasi-randomised cross-over trials. All studies evaluated eyeglasses, there were no studies that evaluated contact lenses or surgery. Seven studies evaluated computer glasses with at least one focal area for the distance of the computer screen with or without additional focal areas in presbyopic persons. Six studies compared computer glasses to other types of glasses; and one study compared them to an ergonomic workplace assessment. The eighth study compared optimal correction of refractive error with the actual spectacle correction in use. Two studies evaluated computer glasses in persons with asthenopia but for the others the glasses were offered to all workers regardless of symptoms. The risk of bias was unclear in five, high in two and low in one study. Asthenopia was measured as eyestrain or a summary score of symptoms but there were no studies on health-related quality of life. Adverse events were measured as headache, nausea or dizziness. Median asthenopia scores at baseline were about 30% of the maximum possible score.Progressive computer glasses versus monofocal glassesOne study found no considerable difference in asthenopia between various progressive computer glasses and monofocal computer glasses after one-year follow-up (mean difference (MD) change scores 0.23, 95% confidence interval (CI) -5.0 to 5.4 on a 100 mm VAS scale, low quality evidence). For headache the results were in favour of progressive glasses.Progressive computer glasses with an intermediate focus in the upper part of the glasses versus other glassesIn two studies progressive computer glasses with intermediate focus led to a small decrease in asthenopia symptoms (SMD -0.49, 95% CI -0.75 to -0.23, low-quality evidence) but not in headache score in the short-term compared to general purpose progressive glasses. There were similar small decreases in dizziness. At medium term follow-up, in one study the effect size was not statistically significant (SMD -0.64, 95% CI -1.40 to 0.12). The study did not assess adverse events.Another study found no considerable difference in asthenopia between progressive computer glasses and monofocal computer glasses after one-year follow-up (MD change scores 1.44, 95% CI -6.95 to 9.83 on a 100 mm VAS scale, very low quality evidence). For headache the results were inconsistent.Progressive computer glasses with far-distance focus in the upper part of the glasses versus other glassesOne study found no considerable difference in number of persons with asthenopia between progressive computer glasses with far-distance focus and bifocal computer glasses after four weeks' follow-up (OR 1.00, 95% CI 0.40 to 2.50, very low quality evidence). The number of persons with headache, nausea and dizziness was also not different between groups.Another study found no considerable difference in asthenopia between progressive computer glasses with far-distance focus and monofocal computer glasses after one-year follow-up (MD change scores -1.79, 95% CI -11.60 to 8.02 on a 100 mm VAS scale, very low quality evidence). The effects on headaches were inconsistent.One study found no difference between progressive far-distance focus computer glasses and trifocal glasses in effect on eyestrain severity (MD -0.50, 95% CI -1.07 to 0.07, very low quality evidence) or on eyestrain frequency (MD -0.75, 95% CI -1.61 to 0.11, very low quality evidence).Progressive computer glasses versus ergonomic assessment with habitual (computer) glassesOne study found that computer glasses optimised for individual needs reduced asthenopia sum score more than an ergonomic assessment and habitual (computer) glasses (MD -8.9, 95% CI -16.47 to -1.33, scale 0 to 140, very low quality evidence) but there was no effect on the frequency of eyestrain (OR 1.08, 95% CI 0.38 to 3.11, very low quality evidence).We rated the quality of the evidence as low or very low due to risk of bias in the included studies, inconsistency in the results and imprecision.

AUTHORS' CONCLUSIONS

There is low to very low quality evidence that providing computer users with progressive computer glasses does not lead to a considerable decrease in problems with the eyes or headaches compared to other computer glasses. Progressive computer glasses might be slightly better than progressive glasses for daily use in the short term but not in the intermediate term and there is no data on long-term follow-up. The quality of the evidence is low or very low and therefore we are uncertain about this conclusion. Larger studies with several hundreds of participants are needed with proper randomisation, validated outcome measurement methods, and longer follow-up of at least one year to improve the quality of the evidence.

Looking forward: In-vehicle auxiliary display positioning affects carsickness

Carsickness is associated with a mismatch between actual and anticipated sensory signals. Occupants of automated vehicles, especially when using a display, are at higher risk of becoming carsick than drivers of conventional vehicles. This study aimed to evaluate the impact of positioning of in-vehicle displays, and subsequent available peripheral vision, on carsickness of passengers. We hypothesized that increased peripheral vision during display use would reduce carsickness. Seated in the front passenger seat 18 participants were driven a 15-min long slalom on two occasions while performing a continuous visual search-task. The display was positioned either at 1) eye-height in front of the windscreen, allowing peripheral view on the outside world, and 2) the height of the glove compartment, allowing only limited view on the outside world. Motion sickness was reported at 1-min intervals. Using a display at windscreen height resulted in less carsickness compared to a display at glove compartment height.

Long-Term Refractive and Phoric Changes in Visual Display Unit (VDU) Operators

Purpose

This study assessed the phoric and refractive changes possibly caused by visual display unit (VDU) activity.

Methods

In a longitudinal trial nearly 6000 VDU operators received two ophthalmological examinations at intervals ranging from 34 to 43 months. The findings from the two examinations were correlated to VDU work (hours daily and years of VDU work), age and sex.

Results

Changes in the refractive state seemed to be mainly age-related. There was a slight tendency toward hyperopia (imbalance of latent hyperopia).

Conclusions

In the analysis of ocular motility, the results show no worsening capable of causing a definitive change from heterophoria to heterotropia. Heterophoric subjects, however, tend to improve both with regular office work and with additional VDU activity.

An investigation into four different sit-stand workstation use schedules

Twelve office workers participated in a study investigating effects of four sit/stand schedules (90-min sit/30-min stand, 80/40, 105/15, and 60/60) via several objective and subjective measures (muscle fatigue, foot swelling, spinal shrinkage, and self-reported discomfort). Results showed that there were no significant differences in shoulder and low back static muscle activities between sitting and standing. Muscle fatigue was developed during workday under all schedules. The longest standing schedule seemed to have a tendency of reducing muscle fatigue. None of the schedules helped or worsened foot swelling and spinal shrinkage. More active break-time activities seemed reducing muscle fatigue and foot swelling. While the self-reported bodily discomfort levels were generally low, the preferred schedules among the participants were varied, although the least standing schedule was the least preferred. We may conclude that effects of using sit-stand workstation to improve musculoskeletal health may be limited but promoting more active break-time activities can help. Practitioner Summary: Sit-stand workstations are used to reduce work-related musculoskeletal disorders. This study shows that office workers prefer sit/stand durations in the range between 1:1 and 3:1. Longer standing may have the potential to reduce muscle fatigue. However, active break-time activities may be more effective in reducing muscle fatigue and foot swelling.

Effect of police mobile computer terminal interface design on officer driving distraction

Several crash reports have identified in-vehicle distraction to be a primary cause of emergency vehicle crashes especially in law enforcement. Furthermore, studies have found that mobile computer terminals (MCTs) are the most frequently used in-vehicle technology for police officers. Twenty police officers participated in a driving simulator-based assessment of visual behavior, performance, workload and situation awareness with current and enhanced MCT interface designs. In general, results revealed MCT use while driving to decrease officer visual attention to the roadway, but usability improvements can reduce the level of visual distraction and secondary-task completion time. Results also suggest that use of MCTs while driving significantly reduces perceived level of driving environment awareness for police officers and increases cognitive workload. These findings may be useful for MCT manufacturers in improving interface designs to increase police officer and civilian safety.

Identification of task demands and usability issues in police use of mobile computing terminals

Crash reports from various states in the U.S. have shown high numbers of emergency vehicle crashes, especially in law enforcement situations. This study identified the perceived importance and frequency of police mobile computing terminal (MCT) tasks, quantified the demands of different tasks using a cognitive performance modeling methodology, identified usability violations of current MCT interface designs, and formulated design recommendations for an enhanced interface. Results revealed that "access call notes", "plate number check" and "find location on map" are the most important and frequently performed tasks for officers. "Reading plate information" was also found to be the most visually and cognitively demanding task-method. Usability principles of "using simple and natural dialog" and "minimizing user memory load" were violated by the current MCT interface design. The enhanced design showed potential for reducing cognitive demands and task completion time. Findings should be further validated using a driving simulation study.