Evaluating Variable Autonomy for a Teleoperated Navigation Task in a Habituated Environment

In this article we review and assess human-centered level of automation (LOA), an alternate approach to traditional, technology-centered design of automation in dynamic-control systems. The objective of human-controlled LOA is to improve human-machine performance by taking into account both operator and technological capabilities. Automation literature has shown that traditional automation can lead to problems in operator situation awareness (SA) due to the out-of-the (control) loop performance problem, which may lead to a negative impact on overall systems performance. Herein we address a standing paucity of research into LOA to deal with these problems. Various schemes of generic control system function allocations were developed to establish a LOA taxonomy. The functions allocated to a human operator, a computer, or both, included monitoring system variables, generating process plans, selecting an “optimal” plan and implementing the plan. Five different function allocation schemes, or LOAs, were empirically investigated as to their usefulness for enhancing telerobot system performance and operator SA, as well as reducing workload. Human participants participated in experimental trials involving a high fidelity, interactive simulation of a telerobot performing nuclear materials handling at the various LOAs. Automation failures were attributed to various simulated system deficiencies necessitating operator detection and correction to return to functioning at an automated mode. Operator performance at each LOA, and during the failure periods, was evaluated. Operator SA was measured using the Situation Awareness Global Assessment Technique, and perceived workload was measured using the NASA-Task Load Index. Results demonstrated improvements in human-machine system performance at higher LOAs (levels involving greater computer control of system functions) along with lower operator subjective workload. However, under the same conditions, operator SA was reduced for certain types of system problems and reaction time to, and performance during, automation failures was substantially lower. Performance during automation failure was best when participants had been functioning at lower, intermediate LOAs (levels involving greater human control of system functions). © 2000 John Wiley & Sons, Inc.

In the near future, vehicles will gradually gain more autonomous functionalities. Drivers’ activity will be less about driving than about monitoring intelligent systems to which driving action will be delegated. Road safety, therefore, remains dependent on the human factor and we should identify the limits beyond which driver’s functional state (DFS) may no longer be able to ensure safety. Depending on the level of automation, estimating the DFS may have different targets, e.g., assessing driver’s situation awareness in lower levels of automation and his ability to respond to emerging hazard or assessing driver’s ability to monitor the vehicle performing operational tasks in higher levels of automation. Unfitted DFS (e.g., drowsiness) may impact the driver ability respond to taking over abilities. This paper reviews the most appropriate psychophysiological indices in naturalistic driving while considering the DFS through exogenous sensors, providing the more efficient trade-off between reliability and intrusiveness. The DFS also originates from kinematic data of the vehicle, thus providing information that indirectly relates to drivers behavior. The whole data should be synchronously processed, providing a diagnosis on the DFS, and bringing it to the attention of the decision maker in real time. Next, making the information available can be permanent or intermittent (or even undelivered), and may also depend on the automation level. Such interface can include recommendations for decision support or simply give neutral instruction. Mapping of relevant psychophysiological and behavioral indicators for DFS will enable practitioners and researchers provide reliable estimates, fitted to the level of automation.

Objectives: This study aimed at measuring the mental and physical workload and its association with the prevalence of wrist disorders. Methods: This cross-sectional study was conducted on 120 female workers working in the assembly line of a porcelain company. The mental and physical workloads and also the prevalence of wrist disorders were measured using the National Aeronautics and Space Administration-Task Load Index (NASA-TLX) questionnaire, the OCRA method, and the Nordic musculoskeletal questionnaire for wrists and hands, respectively. Results: The results showed that 63.3% of the participants had discomfort in their wrist and hands. The Mann-Whitney test results showed that OCRA risk levels were significantly higher in those with wrist pain than those without. The NASA-TLX results revealed that the physical demands and effort (78.79 ± 19.562 and 78.37 ± 20.002, respectively) had the higher scores among the 6 subscales of NASA-TLX, which were significantly higher in those with wrist pain. Conclusions: The findings suggested a high rate of physical and mental workloads and also the wrist disorders in the assembly line workers of the porcelain company. It seems that mental workload is one of the risk factors associated with the incidence of MSDs. Therefore, the high amount of mental workload should be considered as a risk factor.

Objective To compare the subjects' scores of National Aeronautics and Space Administration-task load index (NASA-TLX), the indexes of ECG and performance between the reverse target tracking task and the ordinary target tracking task which simply simulatereverse operationof carrier aircraft landing, and to preliminarily investigate the effect ofreverse operationon pilot's mental workload and its influence factors. Methods Twenty-five young male subjects accomplished the reverse and the ordinary target tracking tasks with two degrees of difficulty. ECG signals were recorded during the resting period before the task, periods of each task and the resting period after the task. Each subjects filled in NASA-TLX scale after the completion of each task and had a score feedback for each task. The scores of NASA-TLX and the indexes of performance were analyzed by analysis of variance (ANOVA) in 2×2 factorial design. The indexes of ECG were analyzed by Friedman M test and the multiple comparisons were carried out by LSD-t test. Results The scores of NASA-TLX and the average tracking distance of the reverse target tracking task were higher than those of the ordinary target tracking task (F=21.70, 16.14, P<0.05) and the highest appeared in the reverse dual task (F=6.67, P<0.05). HR also had the corresponding change (χ2=34.87, P<0.05), but the indexes of HRV had no significant differences. Conclusions Mental workload of the reverse operation task is higher than that of the ordinary operation task if the other conditions are the same. The reverse operation impacts mental workload severer when more information processing is required. Mental demand, physical demand and frustration level are the major influence factors of causing high mental workload in reverse operations. Key words: Workload; Cognition; Habituation, psychophysiologic; Work capacity evaluation; Electrocardiography

PT. SPU Palembang is an industrial company that produces Hospital Furniture and Rehabilitation products with the trademark SHIMA. This study aims to reduce the physical and mental workload received by workers in the Machine Shop Department. This research is focused on the production process .Measurement of physical workload uses the calculation of the worker's heart rate by calculating the percentage of Cardiovascular Load (CVL). Measurement of mental workload using the National Aeronautics and Space Administration Task Load Index (NASA-TLX) score calculation method. The results obtained based on the aspect of NASA-TLX before the proposal almost all workers receive a mental workload with a value of &gt; 80 that is included in the category of heavy mental workloads except Milling-Drilling Workers (4) have a score &lt; 80 in the category of moderate mental workload. After the proposal all workers have a score &lt; 80 so that the mental workload received falls into the medium category. Based on the proposals applied to the Lathe Worker (1) and the Milling-Drilling Worker (4) namely the improvement of work methods in the process of turning, punching, and the proposed holding of a reminder as a tool to remember, the results obtained %CVL from both workers &lt; 30%. Three other workers, although experiencing a decline, remained at &gt; 30%. The category of mental workload received by workers from previously included in the category of heavy mental workload dropped to moderate

BackgroundDifficult surgical procedures may result in a higher mental workload, leading to increased fatigue and subsequent errors. This study was aimed to investigate the effect of repeated simulation training in ureterorenoscopy in a high-fidelity setting on the performance and mental workload of novice operators.MethodsMedical students voluntarily participated in the present simulation study. After a didactic and video-based lecture, they underwent simulation training involving a renal stone case, including a rigid cystoscope component (task 1, performing a WHO checklist, assembling a scope, and insertion of a guide-wire and an access sheath after examining the bladder) and a flexible ureterorenoscope component (task 2, retrieving a stone located in the upper calyx using a basket after inspecting the upper, middle, and lower calyx). Training was performed in a mock operating theater. Technical skills were assessed by one author (an experienced urologist) onsite using an Objective Structured Assessment of Technical Skills (OSATS) score at each training session. The mental workload was subjectively evaluated by the National Aeronautics and Space Administration Task Load Index (NASA-TLX) questionnaire after each training session.ResultsSeventeen students completed a minimum of 6 training sessions (male: female = 10: 7, median age of 22) over a median of 21 days (range, 10–32). In both tasks 1 and 2, the OSATS score improved over the 6 sessions with evidence of plateauing (MANOVA model, task 1: p < 0.0001, task 2: p < 0.0001). In contrast, the NASA-TLX score persistently decreased without plateauing (task 1: p = 0.0005, task 2: p = 0.0028).ConclusionsUnder repeated simulation training in ureterorenoscopy in a high-fidelity setting, participants showed a continual decrease of the mental workload, while the improvement of technical skills reached a plateau over the 6 sessions. Our study showed the important benefit of simulation training to reduce the mental workload by repeated scenario training before actual clinical practice.

Background: Academic staff have different roles which may impose a high mental workolad on them and affect their cognitive function. This study was designed to assess different subscales of mental worklaod and cognitive function in university academic staff. Methods: This was a cross-sectional study on 86 faculty members of Shahid Sadoughi University of Medical Sciences. Stratified sampling was used to select participants from different schools. The participants were divided into basic sciences and clinical faculty members. Mental workload was assessed by National Aeronautics and Space Administration-Task Load Index (NASA-TLX). Cognitive function was assessed by Stroop test. Data were analyzed by SPSS 26 using Shapiro-Wilks test, Student’s T-test, Mann Whitney U test, univariate ANOVA, and Kruskal-Wallis test. The level of significance was 0.05. Results: Mean age and work history of the participants was 43.6±8.6 yr. and 11.7±9.1 yr., respectively. Mental workload, especially two aspects of mental demand and performance, was high and it was significantly higher in the participants from school of medicine and among those with executive/administrative responsibilities. From subscales of mental workload, physical demand was significantly higher among clinical than basic sciences faculty members (p&lt;0.05). Among different aspects of cognitive function, only numbers of congruent errors were significantly higher among clinical faculties. Mental workload and cognitive function were not significantly correlated. Conclusion: This study showed a high level of mental workload in university academic staff, especially in clinical faculty members, but this high mental workload did not affect their cognitive function.

BACKGROUND:Public health and improving the working conditions of people working in hospitals is very important because the health of nurses will have a significant impact on community health. Mental workload is a fundamental concept in the job. Therefore, it is very important to know the relation between mental workload and human performance, especially in nurses. The aim of this study was to determine the relationship between workload with cognitive failures and needle sticks in nurses of Alzahra Hospital in Isfahan.MATERIALS AND METHODS:This descriptive cross-sectional study was conducted on 245 nurses who worked in Al-Zahra Hospital in Isfahan. For collecting data, National Aeronautics and Space Administration Task Load Index (NASA-TLX), the Cognitive Failure questionnaire (CFQ), and accidental needle stick injuries questionnaire were used. Data were collected and analyzed by using SPSS.RESULTS:The mean ± SD of the age of the participants was 35.85 ± 7.15 years. There is a significant relationship between the demographic variables and the frequency of needle stick (P.value < 0.05). The mean of workload among the nurses was 81.75 ± 9.8. In addition, the mean of cognitive failure was 63.46 ± 7.92. The correlation between workload and cognitive failure was not significant (R = -0.017, P.value > 0.05). There is a significant difference between the workload mean (P.value < 0.05) and no significant difference between the cognitive failure mean (P.value > 0.05) in the two groups with needle stick experience and without needle stick experience.CONCLUSION:Needlestick is one of the most common accidents that usually occurs among health workers. Many factors affect the occurrence of these injuries. High mental workload can cause accidents and injuries by affecting the cognitive abilities of nurses. Therefore, it is important to manage the work schedule, training, supervision, as well as complying with safety and health procedures and standards in this occupational group.

BackgroundDespite the challenge of nursing shortage in the world and its subsequent impact on care quality as well as aggravation of the situation by intention to leave service, this issue has not been properly addressed, especially among neonatal and pediatric nurses. The present study aims to identify the relationship between mental workload and musculoskeletal disorders with intention to leave the service among nurses working at neonatal and pediatric departments.MethodsThis descriptive-analytical study was conducted on 145 nurses working at neonatal and pediatric departments in six hospitals in Bushehr Province using full-census method. The data were collected using national aeronautics and space administration-task load index (NASA-TLX), Cornell musculoskeletal discomfort questionnaire(CMDQ) and Mobley and Horner’s voluntary turnover questionnaire. The data were analyzed using descriptive statistics, independent t-test, Mann-Whitney U test, one-way analysis of variance (ANOVA), Kruskal-Wallis test, Pearson’s and Spearman correlation tests and hierarchical linear regression in simultaneous model in SPSS 19.0.ResultsThe mean score of intention to leave the service was 9.57 ± 3.20 (higher than the moderate level) and the mean mental workload was 71.65 ± 15.14 (high level). Pain in at least one of the legs (100%), back (77.3%) and knees (76.6%) was highly prevalent. However, no statistically significant correlation was found between musculoskeletal disorder categories and intention to leave the service (p > 0.05). The regression analysis results revealed among mental workload domains, only effort-induced workload was negatively and significantly correlated with intention to leave the service (p = 0.003; β=-0.078). However, the number of night shifts per month was positively and significantly correlated with intention to leave the service (p = 0.001; β = 0.176).ConclusionsPlanning for appropriate allocation of night shifts, investigating the etiology of musculoskeletal disorders and providing solutions for reducing mental workload should be prioritized by policymakers, while maintaining pediatric nurses’ motivation for making efforts.

Assessment of Radiation Therapy Technologists’ Workload and Situation Awareness: Monitoring 2 Versus 3 Collocated Display Monitors

Aims & Objectives: Rapid Cycle Deliberate Practice (RCDP) is a simulation debriefing methodology that has been compared to post simulation debriefing (PsD) in simulation based medical education (SBME) studies, mostly focused on resuscitations and procedure skills. The aim of this study is to compare the RCDP versus PsD training as methods for experiential learning in the pediatric intensive care unit (PICU) interprofessional SBME sessions. We also measure PICU team workload perception during the simulation scenario using the National Aeronautics and Space Administration Task Load Index (NASA TLX) questionnaire. We hypothesize the RCDP will be more effective than PsD in improving team performance and minimizing cognitive load of learners and facilitators. Methods: Pediatric Critical Care attending physicians, Nurses, Pharmacists and Respiratory Therapists will participate in a 3-hour simulation workshop. Workshops are being conducted from October 2019 - March 2020, and include 5 workshops covering two medical sepsis scenarios. Each session will schedule 1 physician, 2-3 nurses, 1 pharmacist and 1 RT. The first part of the SBME workshop will be PsD and the second half will be RCDP with hard stops and soft stops. The learners complete pre and post-test crew resource knowledge assessments and cognitive load assessments (NASA Task Load Index). Facilitators complete the validated teamwork assessment tool (TEAM Assessment) andNASA Task Index. Results: Raw scores of crew resource knowledge test, TEAM Assessment and NASA Task Load Index between the two studies will be examined. Conclusions: RCDP during interporfessional SBME is feasible and needs to be designed differently in a trainee versus non trainee environment.

Batang Haribarisan is a company engaged in the processing of raw rubber into semi-finished goods (work in process). The type of product produced is crumb rubber. PT. Batanghari Barisan still has a lot of work that is done manually which can cause workload both physically and mentally, therefore it is necessary to measure the physical and mental workload for workers to find out whether the work carried out is included in the workload category that is safe to do in long period of time. The methods that can be used are the Cardio Vascular Load (CVL) and National Aeronautics and Space Administration Task Load Index (NASA-TLX) methods. It is known that the measurement of physical workload using the CVL method, there is workload in the category that needs to be repaired, namely breaker and hammermill operators, with a percentage of 32.05% and 32.65%. Both types of work require high physical labor because most of the work is done standing, monotonous and repetitive. and secondly, the operator's age is considered old, namely 56 years and 47 years, so that it affects the perceived workload. Based on the results of mental workload calculations using the NASA-TLX method that has been carried out. Whereas the mental workload with indicators is Mental Needs (MD) of 170, Physical Needs (PD) of 540, Time Requirements (TD) of 280, Work Performance (OP) of 390, Level of Effort (EF) of 510, and Frustration Level (FR) of 180.

Physiologic monitor alarms occur at high rates in children's hospitals; ≤1% are actionable. The burden of alarms has implications for patient safety and is challenging to measure directly. Nurse workload, measured by using a version of the National Aeronautics and Space Administration Task Load Index (NASA-TLX) validated among nurses, is a useful indicator of work burden that has been associated with patient outcomes. A recent study revealed that 5-point increases in the NASA-TLX score were associated with a 22% increased risk in missed nursing care. Our objective was to measure the relationship between alarm count and nurse workload by using the NASA-TLX. We conducted a repeated cross-sectional study of pediatric nurses in a tertiary care children's hospital to measure the association between NASA-TLX workload evaluations (using the nurse-validated scale) and alarm count in the 2 hours preceding NASA-TLX administration. Using a multivariable mixed-effects regression accounting for nurse-level clustering, we modeled the adjusted association of alarm count with workload. The NASA-TLX score was assessed in 26 nurses during 394 nursing shifts over a 2-month period. In adjusted regression models, experiencing >40 alarms in the preceding 2 hours was associated with a 5.5 point increase (95% confidence interval 5.2 to 5.7; P < .001) in subjective workload. Alarm count in the preceding 2 hours is associated with a significant increase in subjective nurse workload that exceeds the threshold associated with increased risk of missed nursing care and potential patient harm.

BackgroundMusculoskeletal disorders (MSDs) are a leading cause of occupational morbidity. This study investigates the prevalence and associated factors of MSDs across nine body regions among automotive parts assembly workers, considering demographic characteristics, mental workload, and Structured Multidisciplinary work Evaluation Tool (SMET) questionnaire components.MethodsThe cross-sectional study included 211 workers (41.2% female; mean age 33.9 ± 6.9 years). Demographic data, mental workload National Aeronautics and Space Administration-Task Load Index (NASA-TLX), and SMET questionnaire components (physical, environmental, and psychosocial demands) were collected. The Extended Nordic Musculoskeletal Questionnaire was used to assess MSD prevalence. Univariate and multivariate logistic regression analyses identified significant predictors.ResultsThe lifetime prevalence of MSDs was highest in the neck (44.5%) and lower back (44.1%), with the lowest rates in the elbow (6.8%) and hip/thigh (14.2%). Multivariate analyses revealed significant predictors of MSD prevalence. For neck disorders, male sex (OR = 0.361), smoking status (OR = 3.437), surgical history (OR = 2.800), total mental workload (OR = 1.032), and physical demand (OR = 1.396) were key contributors. Shoulder disorders were associated with smoking (OR = 2.542) and illness history (OR = 2.380), whereas upper back disorders were linked to illness history (OR = 3.287) and physical demand (OR = 1.663). Gender-specific vulnerabilities were evident in the hip/thigh and knee regions, with male gender being a significant predictor (hip/thigh: OR = 4.833; knee: OR = 2.711). Surgical history and psychosocial demands are critical factors for ankle/foot disorders.ConclusionsMSDs in assembly line workers result from the interaction of demographic, physical, and psychological factors.

Infrastructure-based sensors provide a potentially promising solution to support the wide adoption of connected and automated vehicles (CAVs) technologies at an early stage. For connected vehicles with lower level of automation that do not have perception sensors, infrastructure sensors will significantly boost its capability to understand the driving context. Even if a full suite of sensors is available on a vehicle with higher level of automation, infrastructure sensors can support overcome the issues of occlusion and limited sensor range. To this end, a cooperative perception modeling framework is proposed in this manuscript. In particular, the modeling focus is placed on a key technical challenge, time delay in the cooperative perception process, which is of vital importance to the synchronization, perception, and localization modules. A constant turn-rate velocity (CTRV) model is firstly developed to estimate the future motion states of a vehicle. A delay compensation and fusion module is presented next, to compensate for the time delay due to the computing time and communication latency. Last but not the least, as the behavior of moving objects (i.e., vehicles, cyclists, and pedestrians) is nonlinear in both position and speed aspects, an unscented Kalman filter (UKF) algorithm is developed to improve object tracking accuracy considering communication time delay between the ego vehicle and infrastructure-based LiDAR sensors. Simulation experiments are performed to test the feasibility and evaluate the performance of the proposed algorithm, which shows satisfactory results.