Visual Display Terminal Operators Research Articles

An Investigation of the Effects of Brain Fatigue on the Sustained Attention of Intelligent Coal Mine VDT Operators.

Intelligent mines require much more mental effort from visual display terminal (VDT) operators. Long periods of mental effort can easily result in operator fatigue, which further increases the possibility of operation error. Therefore, research into how brain fatigue affects the sustained attention of VDT operators in intelligent mines is important. The research methods were as follows: (1) Recruit 17 intelligent mine VDT operators as subjects. Select objective physiological indicators, such as reaction time, error rate, task duration, flicker fusion frequency, heart rate, electrodermal activity, and blink frequency, and combine these with the subjective Karolinska Sleepiness Scale to build a comprehensive brain fatigue evaluation system. (2) According to the fatigue-inducing experiment requirements, subjects are required to carry out mathematical operations in accordance with the rules during the presentation time, determine whether the results of the operations fall within the [7, 13] interval, and continue for 120 min to induce brain fatigue. (3) Perform the standard stimulus button response experiment of the sustained attention to response task, before and after brain fatigue, and compare each result. The results show that: (1) When the standard stimulus appeared in the EEG experiment, the amplitude of the early N100 component before and after brain fatigue was significantly different. When the bias stimulus appeared, the average amplitudes of the P200 component and the late positive component, before and after brain fatigue, were significantly different, suggesting that the brain fatigue of VDT workers in coal mines would reduce sustained attention; (2) After the 120 min of the continuous operation task, the subjects showed obvious brain fatigue. The objective brain fatigue was followed by an increase in reaction time, an increase in error rate, a decrease in flicker fusion frequency, an increase in heart rate, an increase in electrodermal current, an increase in the number of blinks, and a larger pupil diameter, and both the subjective and objective data indicated more significant changes in the subjects’ brain fatigue at the 45th and 90th min. The results of the study could provide insight into the reduction in operational efficiency and safety of VDT operators in intelligent mines due to brain fatigue and further enrich the research in the area of brain fatigue in VDT operations.

Analysis on the quality of life and its influencing factors of visual display terminal operators in Internet enterprises

Objective: To investigate the quality of life of the visual display terminal (VDT) operators in Hangzhou Internet enterprises and to analyze its influencing factors. Methods: Through cluster sampling,, 944 employees were investigated by demographic and general health questions and the MOS 36-Item Short Form Health Survey Questionnaire from October to November in 2016 and carried out statistical analysis. Results: VDT operators' physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional, mental health, physical component summary and mental component summary scores were (86.3±17.0) , (82.5±30.3) , (80.6±16.1) , (56.8±18.6) , (53.7±15.6) , (78.5±17.8) , (81.2±31.9) , (48.8±19.3) , (51.1±8.9) , (43.8±9.1) . Except physical functioning, role-physical and physical component summary scores, the scores of other scales and mental component summary were lower than the norm (P<0.05) . Multivariable logistic regression showed that vegetable intake, sleeping and physical exercise had an impact on the physical component summary score. The influential factors of mental component summary score included marital status, education, neck pain and health concerns. Conclusion: We should pay attention to the quality of life of VDT operators in Internet enterprises, especially their mental health.

Efficacy of Pressure Biofeedback Guided Deep Cervical Flexor Training on Forward Head Posture in Visual Display Terminal Operators

Efficacy of Pressure Biofeedback Guided Deep Cervical Flexor Training on Forward Head Posture in Visual Display Terminal Operators

Effects of Polyphenol on Visual Fatigue Caused by VDT Work

Visual fatigue of VDT (visual display terminal) operators poses a serious problem for corporations where VDT work is a major part of operations. In this study, an investigation in a corporation was carried out to examine the effect of polyphenol on recovery from visual fatigue of the visual function caused by working at a VDT. Three kinds of parameters were used for evaluating the effect of polyphenol. As a subjective evaluation, the first was a questionnaire to ascertain subjective feelings of fatigue. As aspects of a physiological evaluation, the second and third parameters were the accommodative function and the flicker value.

Can clinical measures of upper quarter postural muscle performance predict neck pain in visual display terminal operators?

Can clinical measures of upper quarter postural muscle performance predict neck pain in visual display terminal operators?

A Cross-Country Comparison of Short-and Long-Term Effects of an Ergonomic Intervention on Musculoskeletal Discomfort, Eyestrain and Psychosocial Stress in VDT Operators: Selected Aspects of the International Project

Three groups of data entry female visual display terminal (VDT) workers from Norway (n = 30), Poland (n = 33) and the USA (n = 29) were compared. Before intervention, the Norwegian group reported more neck pain compared with the Polish group. The Polish group reported less shoulder pain than both the U.S. and the Norwegian groups. The clinical examination documented fewer symptoms and signs of musculoskeletal illness among the Polish participants compared with the Norwegian and the U.S. groups. After intervention, the Norwegian group reported a reduction in neck pain while the U.S. group reported a reduction in shoulder pain. The Polish group reported an increase in neck, shoulder and forearm pain at follow-up compared to after intervention. The Polish group recorded higher flexion of the upper arm at follow-up parallel with an increase of pain in the upper part of the body. Visual discomfort showed variable results in the 3 countries.

The effects of ergonomic training and preventive physiotherapy in musculo-skeletal pain

AbstractThe aim of this study was to investigate the effects of ergonomic training and preventive physiotherapy program in visual display terminal (VDT) operators with musculoskeletal pain.The study was carried out at Software Corporation in Turkey and a total 40 volunteer VDT operators consisting of 15 female and 25 male were included the study. The mean age of subjects was 27.30 ± 4.70 years. The subjects were firstly evaluated by the National Institute of Occupational Safety and Health checklist to investigate the exposure of workers to risk factors associated with work-related upper limb problems using VAS (Visual Analog Scale) and RULA (Rapid Upper Limb Assessment). One week after this initial evaluation, the subjects were trained with an ergonomic and preventive physiotherapy program. Two sessions lasting 6 hours in total were given to two groups with 20 subjects in each. After the training all subjects were re-evaluated. There was a significant difference between the results of pretraining and post...

Subclinical impairment in the median nerve across the carpal tunnel among female VDT operators

Sensory nerve conduction velocities in the palm-to-finger (SCV-pf), wrist-to-finger (SCV-wf), wrist-to-palm (SCV-wp), and wrist-to-elbow (SCV-we) segments and the distribution of nerve conduction velocities in the right median nerve were determined among 27 female operators aged 19-37 and 19 healthy women (controls) aged 19-31 to estimate the prevalence of subclinical carpal tunnel syndrome (CTS). Also, the WF/PF ratio, dividing the SCV-wf by the SCV-pf, was calculated to assess abnormalities of nerve conduction within the carpal tunnel. The operators were engaged in data entry in front of a visual display terminal (VDT) for about 6 h/day, and their working duration was between 1 and 17 (mean 6) years. The SCV-wf, SCV-wp, and WF/PF ratio in the operators were significantly lower than those in the controls. The rate of persons with the WF/PF ratio of less than 90%, i.e., below normal limits in the 19 controls, was significantly higher in the operator group (37%) than in the control group (0%). The operators complained of more symptoms related to CTS than did the controls, but any symptoms were not associated with slowing of nerve conduction velocities in the operators. In the controls, the WF/PF ratio was not closely correlated with skin temperature or age despite the presence of significant relations between skin temperature and the SCV-wf, SCV-pf, and SCV-wp; the interpersonal variability of the WF/PF ratio was much smaller than that of all SCVs. In the light of the present and previous studies, the rate of VDT operators with subclinical CTS seems to be high, independent of its symptoms. Also, the WF/PF ratio will be a useful and reliable screening method for the early detection of CTS due to repetitive wrist and finger movements involved in work.

Foot Swelling in VDT Operators with Sitting and Sit-Stand Workstations

In a controlled field study, effect of sit-stand workstations on foot swelling during the course of a workday was monitored in visual display terminal (VDT) operators. Six VDT operators first worked in offices furnished with nonadjustable sitting workstations. Then they worked in offices furnished with sit-stand adjustable furniture for six weeks. In the later setting, they stood for 15 minutes every hour. In both settings, the foot swelling was measured at 8 a.m., 12 p.m., 1 p.m. and 5 p.m. using a foot volumeter. Between 12 p.m. and 1 p.m., subjects walked for 20 minutes and sat for 40 minutes. The results showed that the average right foot swelling in offices with sit-stand adjustable furniture was significantly less than that in offices with nonadjustable furniture, 12.3 ml (1.1 percent) compared to 21 ml (1.8 percent). These results suggest that activity promoted using sit-stand workstations benefits sedentary office workers.

Relationships Between Health Status and Working Conditions and Personalities Among VDT Workers

A total of 486 visual display terminal (VDT) workers were surveyed on their health status, working conditions, type A state, and depression state through questionnaires. They were also divided into three groups by self-assessment: technocentered (TC), technoanxious (TA), and neither (N). The weekly working hours and daily VDT operating hours of the type A group were longer than those of non-type A group. Type A subjects had more symptoms than non-type A subjects. The mean weekly working hours of depressive group was 61.3 hr, much longer than that of the others. The TC subjects worked daily with the VDT for longer hours than the other subjects. The TA subjects felt most dissatisfied with their computer training (TC, 47.4%; N, 64.5%; TA, 91.7%). Awkward VDT operators were more often in the TA group (36.1%) than in the others (TC, 3.8%; N, 10.5%). The TA subjects had a higher previous history of duodenal ulcer than the others (TA, 13.9%; N, 4.6%; TC, 3.8%).

Study of the relationship between lacrimation and blink in VDT work

VDT (Visual Display Terminal) work generates various symptoms in operators' eyes such as strain, a sensation of dryness, the presence of a foreign body, and so on. Research suggests that lacrimal abnormality may be related causally to such symptoms. In this paper, the relationship between lacrimation (the secretion of tears) and the frequency of blink due to VDT work in health subjects and VDT workers with such symptoms, and consequent therapeutic methods, were studied. When lacrimation, BUT (Break-UP Time), and the frequency of blink before and after VDT work compared in the control subjects and VDT-operators, an essential difference was noted in experiment 1 the frequency of blink decreased only during VDT operation, and a decreasing tendency of lacrimation was also noted while lacrimation before operation was already less in the VDT group; no large variation was noted before or after VDT operation. The frequency of blink was relatively high during operation, and a decreasing tendency of BUT was noted, compared with that for control subjects. In experiment 2, lacrimation increased remarkably in four eyes (of two operators), and relief from the subjective symptoms was noted. However, BUT intactly reduced similarly before the use of a gelatin rod during the whole process. The insertion of a gelatin rod was consecutively carried out every two weeks for approximately eight months; the development of complications such as dacryosolenitis, etc., was not noted. From these results, it is considered that the insertion of a gelatin rod is clinically useful for VDT operators with decreasing lacrimation.

Does visual display terminal work provoke rosacea?

According to some reports, mainly from Norway, visual display terminal (VDT) work has been thought to cause rashes. In conjunction with an epidemiological study of office employees and VDT work, a dermatological examination was made. No case demonstrated the clinical picture described from Norway among VDT operators, but subjects with rosacea, seborrhoeic dermatitis and acne were over-represented in the VDT-exposed group. The object of the present study was to see whether patients with rosacea experienced aggravation of their symptoms as a result of VDT work and whether they showed a particular clinical picture. All subjects fit for work among the patients diagnosed as rosacea or perioral dermatitis during 1982 were selected for the study. The methods included a questionnaire on VDT work and suspected impairment of the skin disease, clinical examination and telephone interviews. 179 subjects were selected; 42 of them worked daily with VDT and 8 of them suspected impairment due to VDT work. The results imply that a relationship may exist between rosacea and VDT work. To what factor in the work this may be ascribed is still unclear. Those subjects whose symptoms were aggravated did not show any particular clinical picture.

Display station anthropometrics: preferred height and angle settings of CRT and keyboard.

This study investigates display station physical adjustments preferred by a sample of visual display terminal operators. Participants in the study were selected to assure representation of extremely short and extremely tall persons, as well as persons of midrange physical stature. Individual operators were led through a step-by-step sequence to determine their preferred initial settings of seat height, keyboard height and slope angle, and CRT height and tilt angle. Each operator then performed a brief text input task, after which final preferred adjustments were measured. Intermeasure correlation strongly suggest that “flat” (low slope angle) keyboards are inappropriate for short operators who select low seat heights. In addition, the keyboard angle adjustments preferred by most operators substantially exceed a current German ergonomic display station requirement.

Occupational stress factors in visual display terminal (VDT) operation: a review of empirical research†

Abstract A review of the literature involving empirical research (experimental and field investigations) on stressful aspects of visual display terminal (VDT) operation is presented. Studies reviewed included assessment of visual fatigue and/or performance, musculoskeletal symptoms and operator attitudes towards job demands and quality of working life. In addition, some investigation included discussions and evaluations of the physical attributes of VDT workplaces; including ergonomic factors (task lighting, glare conditions, anthropometric configuration of VDT and accompanying furniture), environmental factors (temperature, humidity, radiation) and psychosocial factors (job demand, work content, work-rest schedules). The literature reveals that levels of visual and musculoskeletal complaints among VDT operators are high. Moreover, ergonomic field assessment of VDT workplaces indicate that the majority of those examined were suboptimal with respect to existing recommendations regarding lighting, glare control and anthropometric dimensions of screen, keyboard, desk and chair. Nevertheless, evidence of causal linkages between specific ergonomic attributes of the workplace and specific patterns of symptomatology are lacking. Finally, work demand and task structure attributes to the VDT operation were demonstrated to have strong effects on incidences of reports of visual and postural symptoms as well as on psychosocial attitudinal indicators. Hence, it is argued that approaches toward stress reduction must include job content as well as ergonomic factors.