The effect of increasing the illumination on operators' visual performance in the control-room of a combined cycle power plant

Ambient light intensity affecting ultrasound operator detection of liver lesions in cine-clips

INTRODUCTION

Ambient light (AL) is an important factor to improve ultrasound pathology detection. However, there are no established room AL levels recommended during an ultrasound examination. We aim to examine the diagnostic accuracy using different intensity of AL for the detection of liver lesions in anonymised pre-recorded cine-clips.

METHODS

Eight ultrasound operators with 5-14 years' professional experiences were prospectively recruited to evaluate 51 randomised cine-clips directly from one ultrasound machine. These 15-s clips of the right lobe of the liver in longitudinal and transverse planes were meant to simulate the ultrasound examination. Operators reviewed all cine-clips and responded to two questions per cine-clip regarding their detection performance under 3 AL settings; 3, 15 and 25 lux, at one lighting per visit. A repeat visit under each AL was performed to assess for intra-operator variability. Each operator completed six visits in total, with at least a 2-day washout period. The operators' performance was compared against imaging reference standards from contrast CT/MRI for cine-clips with lesion and serial US for those without.

RESULTS

AL with highest degree of diagnostic accuracy was found to be at 25 lux. Results from 8 operators revealed sensitivity ranged from 79% to 100%, specificity ranged from 94% to 100%. Positive and negative predictive values were up to 100% with AL at 25 lux. Both intra-and interrater reliability were excellent at 0.85-1.0 (0.79-0.98) and 0.98 (0.97, 0.99) respectively, with AL at 25 lux.

CONCLUSION

This study proved that ambient light intensity affects the ultrasound operator detection of liver lesions on cine-clips.

IMPLICATIONS FOR PRACTICE

Identifying suitable AL levels will influence future ultrasound room construct.

Randomized trial comparing the effects of a 3D head-up system and microscope eyepiece-assisted simulated vitrectomy with intraocular illumination on the ocular surface of an operator

BACKGROUND

To compare the effects of a 3D head-up system and microscope eyepiece-assisted simulated vitrectomy intraocular illumination on the ocular surface of an operator.

METHODS

This was a prospective randomized controlled study. According to the application system, thirty ophthalmic operators (60 eyes) were randomly divided into 3D and eyepiece groups. Under different intensities of intraocular illumination, operators in both groups viewed the fundus model through a 3D display screen or microscopic eyepiece for 2 h. Objective examinations and a subjective symptom questionnaire were used immediately after the test to evaluate the ocular surface of the operators. Objective examinations included nonintrusion tear meniscus height (NIKTMH), nonintrusion break-up time (NIKBUT), and bulbar redness and strip meniscometry tube (SMTube) measurements. Statistical analyses were performed by using SPSS 26.0 software.

RESULTS

After the test, the NIKTMH, NIKBUT and SMTube measurements decreased; however, the degree of change varied among the groups of different systems. The differences between the 3D group and the eyepiece group in NIKTMH measurements, SMTube measurements, subjective symptom scores (eye dryness, difficulty focusing, and cervical pain), and light intensity reaching the ocular surface of the operators were statistically significant (P < 0.05). All of the objective and subjective tests showed that the 3D group had fewer effects on the NIKTMH and SMTube measurements, and the subjective comfort of the 3D group was greater.

CONCLUSION

For both 3D screens and eyepieces, simulated vitrectomy with intraocular illumination for two hours can lead to discomfort and abnormalities in the operator's ocular surface; however, these abnormalities are less severe in the 3D group.

TRIAL REGISTRATION

This trial was registered on December 22, 2022, at the Chinese Clinical Trials Registry with NO. ChiCTR2200066989.

Association Between Lighting Level to Subjective Complaints of Visual Fatigue on Operators in the Auto Welder Section

Introduction: Good intensity of light dramatically affects the eyes. If there is less intensity of light. the eye muscles contract as much as possible to see objects or vice versa. If this happens continuously, it will cause damage to the eyes. Based on the preliminary study, it was found that as the auto welder operators have the task to observe the results of the auto welder engine to determine the quality of the welder, this type of work needs accuracy so that the right lighting intensity is required. This study aimed to determine the association between the lighting level and subjective visual fatigue complaints on operators in the auto welder section. Methods: The research method used was quantitative, with a cross- sectional approach and observational method. The samples in this study were 18 respondents from the total sampling technique. The instrument used was the Visual Fatigue Index (VTI) questionnaire. Moreover, the analysis of the study results used the one sample T-test statistical test to determine the association between the dependent and independent variables. Results: The one sample T-test results showed p-value = 0.012 < α = 0.05. This result showed an association between the lighting leveland subjective visual fatigue complaints on operators in the auto welder section. Conclusion: In this research, it was found that the majority of lighting levels that did not meet the standards had an association with subjective complaints of visual fatigue on the operators in the auto welder section.Keywords: auto welder, lighting, visual fatigue

An empirical regression model toward optimized ergonomic conditions for monitoring room operators using RSM

Purpose

This study aims to provide an ergonomic design of the monitoring room that has resulted in safe, functional and comfortable environment for the operators, which may lead to improve the efficiency. Currently, uses of closed‐circuit televisions to monitor the critical environments are widely applicable. The information is continuously transferred and analyzed through a center called monitoring room.

Design/methodology/approach

Here, through creating a systematic analysis, a series of experiments was performed initially to evaluate and then optimize the parameters such as illumination, visual angle, operator-screen distance, number of scenes display in a single screen, workstation height, screen dimension and monitoring time that may affect the visual skill of the operators. Taguchi orthogonal array was used to analyze the significance of parameters on operator’s response time to a threat. The five parameters were distinguished as significant. Later response surface methodology was utilized to optimize the parameters.

Findings

Quadratic empirical model developed for the response time exposes the optimum response time was achievable at illumination of 500 lux, visual angle of 13°, operator-screen distance of 60 cm, three scenes, workstation height of 120 cm, screen dimension of 34” and monitoring time of 15 min. This shortened the response time by 28 per cent. The adequacy of the fitted model was successfully verified using the confirmation test with α = 95 per cent.

Originality/value

The novelty of this work lies in the application of a systematic statistical analysis, which enables considering the interaction among the noise parameters and controllable one simultaneously. Furthermore, the obtained regression model can widely be used for adjusting the parameters accordingly based on various anthropometric data.