Space Administration Task Load Index Research Articles

Evaluation of drivers' mental workload based on multi-modal physiological signals

Accurately assessing the driver's mental workload is of great significance to reduce the traffic accidents caused by the driver's mental overload. This study aims to evaluate drivers' mental workload in simulated typical driving scenarios, with <italic>N</italic>-back cognitive tasks used to manipulate varied levels of task difficulty. We collect data on multi-modal physiological signals including electroencephalogram (EEG), electrocardiogram (ECG), and electrodermal activity (EDA) signals, and subjective mental load of the National Aeronautics and Space Administration task load index (NASA_TLX) during the task completion process of the driver in the experiment, and propose a series of mental workload classification models based on feature analysis and pattern recognition of the multi-modal physiological signals. These classification models are verified by machine learning algorithms of random forest, decision tree and <italic>k</italic>-nearest neighbor models. The results show that the accuracy of classification models varies with different modalities of physiological signals. EEG-based classification models yield the highest accuracy among single-modal classification models, followed by EDA-based and ECG-based models. Multi-modal-based classification models generally perform better than single-modal classification models. The random forest classification algorithm based on three-modal physiological signals of EEG, ECG and EDA has the highest classification accuracy.

Exploring Workload Associated With Learning Foot Core Exercises

Patients and clinicians have expressed frustration when learning or teaching intrinsic foot muscle exercises. However, there is limited information on how patients perceive the workload of an exercise. This study evaluates participants’ perceptions of workload while learning intrinsic foot muscle exercises with or without neuromuscular electrical stimulation. Twenty-six individuals completed a 4-week supervised intrinsic foot muscle training program. Thirteen participants utilized neuromuscular electrical stimulation during the initial 2 weeks of training. Participant perceptions of workload, measured by the National Aeronautics and Space Administration Task Load Index, revealed decreasing load over 2 weeks and minimal load at 4 weeks. Inclusion of neuromuscular electrical stimulation did not affect perception of load of skill acquisition.

Nurse workload, missed nursing care, and the contributing factors in the Neonatal Intensive Care Unit in a limited resource setting: A case from Indonesia

Background: Nurses who are in charge of the Neonatal Intensive Care Units (NICUs) have a different workload and work assignments compared to other units. Evidence suggests that higher nurse workloads will increase the risk of missed nursing care. Missed nursing care in the NICU will eventually worsen the neonatal prognosis. This is a major problem in developing countries, which currently still have a high neonatal mortality rate. Methods: This was a cross sectional study using questionnaires to collect data from 48 nurses who work in Dr. Soetomo Hospital NICU from April 15th 2021 to July 25th 2021. The collected data was then processed with descriptive statistics, meanwhile the correlation between workload with missed nursing care was analyzed with Pearson and Spearman correlation. Results: The total mean of NICU nurse workload score according to the NASA-TLX (National Aeronautics and Space Administration Task Load Index) was 68.36, indicating a moderate overall workload, with effort as the highest component. Overall, 91.67% of the nurses had missed at least 1 out of 21 basic neonatal nursing care components. Labor resource factor was the most frequent missed nursing care factor, in which urgent patient situations were the most frequent problem. There was no significant correlation between the total nurse workload and the frequency of any missed nursing care (P=0.536). Conclusions: Effort was the biggest component of the NICU nurse total workload. The most frequently missed nursing care was giving emotional support for the patient’s parents and/or family. Labor resource factor was the most frequent problem which caused missed nursing care. However, there is no statistically significant correlation between the total workload with the frequency of missed nursing care.

Mental Workload, Occupational Fatigue and Musculoskeletal Disorders of Forestry Professionals

Musculoskeletal disorders (MSD) comprise one of the most important occupational health issues in forestry professions. The purpose of the study was to examine the association among musculoskeletal disorders, antrhopometric and personal data, mental workload and occupational fatigue in forest professionals in northern Iran by means of the Nordic Musculoskeletal Questionnaire (NMQ), the National Aeronautics and Space Administration Task Load Index (NASA-TLX), and the Swedish Occupational Fatigue Inventory (SOFI). More than eight out of every ten subjects reported at least one MSD symptom during the past 12 months, with lower back (72.5%), feet and ankles (49%) and neck (41.2%) being the more frequently affected body regions. Similar MSD prevalences were reported for the period of seven days prior to data collection. Both the mental workload (grand mean 73.18±7.54) and occupational fatigue (grand mean 106.20±24.53) achieved high scores. MSD prevalence was found to be correlated with the SOFI score and the NASA-TLX score during the last year and seven days prior to data collection, respectively.Overall, the study results confirm the very demanding nature of the forest professions, which are characterized by high MSD prevalence, increased occupational fatigue and high mental workload. Given the small-scale forestry characteristics in the study area, taking measures such as introducing vocational training and promoting the use of personal protective equipment are some first necessary steps for the local forestry workforce.

Intraoperative navigation system with a multi-modality fusion of 3D virtual model and laparoscopic real-time images in laparoscopic pancreatic surgery: a preclinical study

BackgroundLaparoscopy is widely used in pancreatic surgeries nowadays. The efficient and correct judgment of the location of the anatomical structures is crucial for a safe laparoscopic pancreatic surgery. The technologies of 3-dimensional(3D) virtual model and image fusion are widely used for preoperative planning and intraoperative navigation in the medical field, but not in laparoscopic pancreatic surgery up to now. We aimed to develop an intraoperative navigation system with an accurate multi-modality fusion of 3D virtual model and laparoscopic real-time images for laparoscopic pancreatic surgery.MethodsThe software for the navigation system was developed ad hoc. The preclinical study included tests with the laparoscopic simulator and pilot cases. The 3D virtual models were built using preoperative Computed Tomography (CT) Digital Imaging and Communications in Medicine (DICOM) data. Manual and automatic real-time image fusions were tested. The practicality of the navigation system was evaluated by the operators using the National Aeronautics and Space Administration-Task Load Index (NASA-TLX) method.ResultsThe 3D virtual models were successfully built using the navigation system. The 3D model was correctly fused with the real-time laparoscopic images both manually and automatically optical orientation in the preclinical tests. The statistical comparative tests showed no statistically significant differences between the scores of the rigid model and those of the phantom model(P > 0.05). There was statistically significant difference between the total scores of automatic fusion function and those of manual fusion function (P = 0.026). In pilot cases, the 3D model was correctly fused with the real-time laparoscopic images manually. The Intraoperative navigation system was easy to use. The automatic fusion function brought more convenience to the user.ConclusionsThe intraoperative navigation system applied in laparoscopic pancreatic surgery clearly and correctly showed the covered anatomical structures. It has the potentiality of helping achieve a more safe and efficient laparoscopic pancreatic surgery.

Evaluating mental workload during multitasking in simulated flight.

BackgroundPilots must process multiple streams of information simultaneously. Mental workload is one of the main issues in man–machine interactive mode when dealing with multiple tasks. This study aimed to combine functional near‐infrared spectroscopy (fNIRS) and electrocardiogram (ECG) to detect changes in mental workload during multitasking in a simulated flight.MethodsTwenty‐six participants performed three multitasking tasks at different mental workload levels. These mental workload levels were set by varying the number of subtasks. fNIRS and ECG signals were recorded during tasks. Participants filled in the national aeronautics and space administration task load index (NASA‐TLX) scale after each task. The effects of mental workload on scores of NASA‐TLX, performance of tasks, heart rate (HR), heart rate variability (HRV), and the prefrontal cortex (PFC) activation were analyzed.ResultsCompared to multitasking in lower mental workload conditions, participants exhibited higher scores of NASA‐TLX, HR, and PFC activation when multitasking in high mental workload conditions. Their performance was worse during the high mental workload multitasking condition, as evidenced by the higher average tracking distance, smaller number of response times, and longer response time of the meter. The standard deviation of the RR intervals (SDNN) was negatively correlated with subjective mental workload in the low task load condition and PFC activation was positively correlated with HR and subjective mental workload in the medium task load condition.ConclusionHR and PFC activation can be used to detect changes in mental workload during simulated flight multitasking tasks.

Nasal Glucagon Is Easier to Use and More Preferred and Needs Less Effort to Administer Than Injectable Glucagon: User Perceptions of Glucagon Administration During Severe Hypoglycemia Simulation

ObjectiveTo evaluate ease of use, user preference, and effort required to use nasal glucagon (NG) versus injectable glucagon needing reconstitution (IG) in simulations of severe hypoglycemia (SH)—a challenge for caregivers of a person with diabetes (PWD) in real-life. MethodsIn this randomized, crossover study, high-fidelity manikins placed in mock representative high-stress environments were used to simulate an SH rescue. Thirty-two trained (by PWDs) and 33 untrained participants attempted NG and IG administrations and then completed questionnaires regarding ease of use, preference, and workload for each device. ResultsMore trained users agreed that NG was easy to use (87.1% vs 54.8%) and prepare (80.6% vs 51.6%) and had confidence to use NG correctly (93.5% vs 54.8%) than those who agreed the same for IG (P < .05). Untrained users reported similar differences, favoring NG in all parameters. In direct device comparison across all simulations, 80.6% of trained users and 93.5% of untrained users preferred NG over IG—a preference largely sustained regardless of the success or failure of administration. Among PWDs, 90.3% considered NG device as safer than IG during an SH event. In the assessment of workload required to administer glucagon, the weighted mean National Aeronautics and Space Administration Task Load Index scores were 37.8 for NG and 48.4 for IG (P = .0020). ConclusionParticipants in this study considered NG easier, more preferred, required less effort for administration, and more intuitive to use than reconstitutable IG, irrespective of whether there was prior training. NG improves the potential for successful administration of glucagon, better preparedness, and increased adoption of glucagon for SH rescue.

PENGUKURAN BEBAN KERJA OPERATOR CRANE DENGAN METODE NASA-TLX DI PELABUHAN KHUSUS CNOOC SES

Abstract The problem raised in this study is how the mental load experienced by the crane pedestal operator can be measured using the National Aeronautics and Space Administration Task Load Index (NASA-TLX) method. To then take control measures to reduce or eliminate the mental burden when operating a pedestal crane so that the factor of work accidents when operating a pedestal crane can be eliminated or reduced. The results showed one worker with a very high workload and three workers with a high workload. The element that has the level of influence on the workload is the element of effort with an average value of 23.3. By looking at the results of data processing and the high level of workload on all workers which can affect the work system to be less good, it is necessary to take countermeasures and improvements so that the possibility of work accidents can be eliminated or reduced Keywords: Mental load, NASA-TLX, Pedestal crane

Developing a measurement tool for assessing situation awareness of operator in the MCR of SMR

Automated action is one of the main features in the modern main control room (MCR) of nuclear power plants including small and modular reactors (SMR). The automated systems can increase the safe operation of the plants and can make it easier for operators to monitor and control the plant. However, it can reduce the awareness of operators about the current status of the plant. This paper discusses a tool to measure the situation awareness of operators of MCR of Nuscale, one of SMR type reactor. The tool is developed based on the National Aeronautics and Space Administration Task Load Index (NASA-TLX) that measures operator workload that affects the situation awareness based on the 6 subscales: mental demand, physical demand, temporal demand, frustration, effort, and performance. The types of workloads of the operator are investigated and some questioners related to the 6 subscales are made. The result shows that the tool is suitable for assessing the situation awareness of the operator of MCR of Nuscale.

Comparison of safety and usability between peristaltic and pneumatic large-volume intravenous smart pumps during actual clinical use

ObjectiveTo describe and compare safety and usability between a peristaltic large-volume intravenous smart pump (IVSP) and a novel pneumatic large-volume IVSP during clinical use.MethodsA prospective, comparative study was conducted in...

Developing a User-Centered Digital Clinical Decision Support App for Evidence-Based Medication Recommendations for Type 2 Diabetes Mellitus: Prototype User Testing and Validation Study.

BackgroundClosing the gap between care recommended by evidence-based guidelines and care delivered in practice is an ongoing challenge across systems and delivery models. Clinical decision support systems (CDSSs) are widely deployed to augment clinicians in their complex decision-making processes. Despite published success stories, the poor usability of many CDSSs has contributed to fragmented workflows and alert fatigue.ObjectiveThis study aimed to validate the application of a user-centered design (UCD) process in the development of a standards-based medication recommender for type 2 diabetes mellitus in a simulated setting. The prototype app was evaluated for effectiveness, efficiency, and user satisfaction.MethodsWe conducted interviews with 8 clinical leaders with 8 rounds of iterative user testing with 2-8 prescribers in each round to inform app development. With the resulting prototype app, we conducted a validation study with 43 participants. The participants were assigned to one of two groups and completed a 2-hour remote user testing session. Both groups reviewed mock patient facts and ordered diabetes medications for the patients. The Traditional group used a mock electronic health record (EHR) for the review in Period 1 and used the prototype app in Period 2, while the Tool group used the prototype app during both time periods. The perceived cognitive load associated with task performance during each period was assessed with the National Aeronautics and Space Administration Task Load Index. Participants also completed the System Usability Scale (SUS) questionnaire and Kano Survey.ResultsAverage SUS scores from the questionnaire, taken at the end of 5 of the 8 user testing sessions, ranged from 68-86. The results of the validation study are as follows: percent adherence to evidence-based guidelines was greater with the use of the prototype app than with the EHR across time periods with the Traditional group (prototype app mean 96.2 vs EHR mean 72.0, P<.001) and between groups during Period 1 (Tool group mean 92.6 vs Traditional group mean 72.0, P<.001). Task completion times did not differ between groups (P=.23), but the Tool group completed medication ordering more quickly in Period 2 (Period 1 mean 130.7 seconds vs Period 2 mean 107.7 seconds, P<.001). Based on an adjusted α level owing to violation of the assumption of homogeneity of variance (Ps>.03), there was no effect on screens viewed and on perceived cognitive load (all Ps>.14).ConclusionsThrough deployment of the UCD process, a point-of-care medication recommender app holds promise of improving adherence to evidence-based guidelines; in this case, those from the American Diabetes Association. Task-time performance suggests that with practice the T2DM app may support a more efficient ordering process for providers, and SUS scores indicate provider satisfaction with the app.

ANALISIS BEBAN KERJA MENTAL PADA KARYAWAN OFFICE MENGGUNAKAN METODE NASA-TLX DI PT. TOTAL AUTO MANDIRI

Field Work Practice (FWP) is a form of systematic and synchronous implementation of educational programs at schools/campuses with programs for mastering skills obtained through direct work activities in the world of work to achieve a certain level of expertise. This study aims to determine the mental workload of office employees using the NASA-TLX method at PT. Total auto self. The results of the study using the National Aeronautics And Space Administration Task Load Index (NASA-TLX) method from the 2 employees/office pt. Total Auto Mandiri. All of them have a high category of mental workload. For the first worker on behalf of Icha Septiawati, female gender, office position, accounting department has wwl with a rate of 98.6%. And for the second worker on behalf of Abdulrahman, male gender, office position, accounting section has wwl with a rate of 86%. Keywords: Mental workload, NASA TLX, Office employee

Workload of Swedish Special Forces Operators Experienced During Stressful Simulation Training: A Pilot Study.

Stress week was included during training of Special Forces (SF) Operators in Sweden to test their ability and limits for handling stress in different unknown situations and environments at a military training facility in Sweden. The aim of the study was to examine the effects of stress and workload experienced in various tasks during firefighting and military medicine simulation training. This pilot study was performed during the second day of stress week. The National Aeronautics and Space Administration Task Load Index (NASA-TLX) is a validated, subjective, and multidimensional assessment tool for rating perceived workload with six subscales: mental demand, physical demand, temporal demand, performance, effort, and frustration. These subscales were used as an indicator of stress experienced. The different tasks were assessed by the SF Operators by rating the NASA-TLX subscales for each task, which were then analyzed and compared using ANOVA. There was a significant difference between the two simulation exercises assessed by the participants and instructors, and both groups considered firefighting to be more demanding than medical. The participants perceived the mental and physical demands as more demanding in the firefighting exercises, as well as for the level of frustration and effort. However, no differences regarding performance or temporal demands between the simulation exercises were found. The principle "train as you fight" implies difficult and demanding situations. When exposing Swedish SF Operators to challenging situations, assessment of perceived stress and performance are possible.

Clinical Validation of BCI-Controlled Wheelchairs in Subjects With Severe Spinal Cord Injury.

Brain-controlled wheelchairs are one of the most promising applications that can help people gain mobility after their normal interaction pathways have been compromised by neuromuscular diseases. The feasibility of using brain signals to control wheelchairs has been well demonstrated by healthy people in previous studies. However, most potential users of brain-controlled wheelchairs are people suffering from severe physical disabilities or who are in a "locked-in" state. To further validate the clinical practicability of our previously proposed P300-based brain-controlled wheelchair, in this study, 10 subjects with severe spinal cord injuries participated in three experiments and completed ten predefined tasks in each experiment. The average accuracy and information transfer rate (ITR) were 94.8% and 4.2 bits/min, respectively. Moreover, we evaluated the physiological and cognitive burdens experienced by these individuals before and after the experiments. There were no significant changes in vital signs during the experiment, indicating minimal physiological and cognitive burden. The patients' average systolic blood pressure before and after the experiment was 113±13.7 mmHg and 114±11.9 mmHg, respectively (P = 0.122). The patients' average heart rates before and after the experiment were 79±8.4/min and 79±8.2/min, respectively (P = 0.147). The average task load, measured by the National Aeronautics and Space Administration task load index, ranged from 10.0 to 25.5. The results suggest that the proposed P300-based brain-controlled wheelchair is safe and reliable; additionally, it does not significantly increase the patient's physical and mental task burden, demonstrating its potential value in clinical applications. Our study promotes the development of a more practical brain-controlled wheelchair system.

Mental Workload Analysis Using NASA-TLX Method at Bank XYZ - Medan Balaikota Consumer Loan Unit

All human activities, whether light, medium, or heavy, must have or contain a workload. Basically, every human being has a varied workload capacity, thus it's not inconceivable that the workload experienced by one worker differs from that of another, because there are a variety of elements that influence the difference in workload capacity. Sales and processing teams are under a lot of pressure to meet credit disbursement targets, which puts them under a lot of mental strain. A worker will experience work stress if he is given an excessive workload. When it comes to work, the influence of stress will result in a decline in performance, efficiency, and productivity of the work in question. To address this issue, a study based on the National Aeronautics and Space Administration Task Load Index (NASA-TLX) approach will be conducted to measure the mental strain of personnel in the Medan Balaikota consumer loan unit. NASA-TLX is a way for analyzing the mental workload of workers who must do a variety of tasks at work. Mental demand, physical demand, temporal demand, performance, effort, and frustration dimensions are among the six variables to be measured. Thirty workers of PT Bank XYZ Consumer Loan Unit Medan Balaikota Branch were surveyed. The NASA-TLX survey method is a quantitative descriptive methodology that was utilized to test in this study. According to the findings of the study, the NASA-TLX average score of PT Bank XYZ Consumer Loan Unit Medan Balaikota Branch employees obtained through research had a modest value. The result is a score of 77. Keywords: Mental Workload, NASA-TLX.

Using a 360° Virtual Reality or 2D Video to Learn History Taking and Physical Examination Skills for Undergraduate Medical Students: Pilot Randomized Controlled Trial

BackgroundLearning through a 360° virtual reality (VR) or 2D video represents an alternative way to learn a complex medical education task. However, there is currently no consensus on how best to assess the effects of different learning materials on cognitive load estimates, heart rate variability (HRV), outcomes, and experience in learning history taking and physical examination (H&P) skills.ObjectiveThe aim of this study was to investigate how learning materials (ie, VR or 2D video) impact learning outcomes and experience through changes in cognitive load estimates and HRV for learning H&P skills.MethodsThis pilot system–design study included 32 undergraduate medical students at an academic teaching hospital. The students were randomly assigned, with a 1:1 allocation, to a 360° VR video group or a 2D video group, matched by age, sex, and cognitive style. The contents of both videos were different with regard to visual angle and self-determination. Learning outcomes were evaluated using the Milestone reporting form. Subjective and objective cognitive loads were estimated using the Paas Cognitive Load Scale, the National Aeronautics and Space Administration Task Load Index, and secondary-task reaction time. Cardiac autonomic function was assessed using HRV measurements. Learning experience was assessed using the AttrakDiff2 questionnaire and qualitative feedback. Statistical significance was accepted at a two-sided P value of <.01.ResultsAll 32 participants received the intended intervention. The sample consisted of 20 (63%) males and 12 (38%) females, with a median age of 24 (IQR 23-25) years. The 360° VR video group seemed to have a higher Milestone level than the 2D video group (P=.04). The reaction time at the 10th minute in the 360° VR video group was significantly higher than that in the 2D video group (P<.001). Multiple logistic regression models of the overall cohort showed that the 360° VR video module was independently and positively associated with a reaction time at the 10th minute of ≥3.6 seconds (exp B=18.8, 95% CI 3.2-110.8; P=.001) and a Milestone level of ≥3 (exp B=15.0, 95% CI 2.3-99.6; P=.005). However, a reaction time at the 10th minute of ≥3.6 seconds was not related to a Milestone level of ≥3. A low-frequency to high-frequency ratio between the 5th and 10th minute of ≥1.43 seemed to be inversely associated with a hedonic stimulation score of ≥2.0 (exp B=0.14, 95% CI 0.03-0.68; P=.015) after adjusting for video module. The main qualitative feedback indicated that the 360° VR video module was fun but caused mild dizziness, whereas the 2D video module was easy to follow but tedious.ConclusionsOur preliminary results showed that 360° VR video learning may be associated with a better Milestone level than 2D video learning, and that this did not seem to be related to cognitive load estimates or HRV indexes in the novice learners. Of note, an increase in sympathovagal balance may have been associated with a lower hedonic stimulation score, which may have met the learners’ needs and prompted learning through the different video modules.Trial RegistrationClinicalTrials.gov NCT03501641; https://clinicaltrials.gov/ct2/show/NCT03501641

Validation of the National Aeronautics and Space Administration Task Load Index (NASA-TLX) adapted for the whole day repeated measures context

Our objective was to investigate the validity of four-item and six-item versions of the National Aeronautics and Space Administration Task Load Index (NASA-TLX, or TLX for short) for measuring workload over a whole day in the repeated measures context. We analysed data on 51 people with type 1 diabetes from whom we collected ecological momentary assessment and daily diary data over 14 days. The TLX was administered at the last survey of every day. Confirmatory factor analysis fit statistics indicated that neither the TLX-6 nor TLX-4 were a unidimensional representation of whole day workload. In exploratory analyses, another set of TLX items we refer to as TLX-4v2 was sufficiently unidimensional. Raw sum scores from the TLX-6 and TLX-4v2 had plausible relationships with other measures, as evidenced by intra-person correlations and mixed-effects models. TLX-6 appears to capture multiple factors contributing to workload, while TLX-4v2 assesses the single factor of ‘mental strain’. Practitioner Summary: Using within-person longitudinal data, we found evidence supporting the validity of a measure evaluating whole-day workload (i.e. workload derived from all sources, not only paid employment) derived from the NASA-TLX. This measure may be useful to assess how day-to-day variations in workload impact quality of life among adults. Abbreviations: NASA-TLX or TLX: National Aeronautics and Space Administration Task Load Index; TLX-6: six item version of the NASA-TLX; TLX-4: four item version of the NASA-TLX, TLX-4v2: four item NASA-TLX version two; NIOSH: National Institute for Occupational Safety and Health; CFA: confirmatory factor analysis; T1D: type 1 diabetes; EMA: ecological momentary assessment; BG: blood glucose; SD: standard deviation; CV: coefficient of variation; RMSEA: root mean square error of approximation; CFI: comparative fit index; TLI: Tucker-Lewis Index; SRMR: standardized root mean square residual; AIC: Akaike information criterion; BIC: Bayesian information criterion; χ2: Chi-square statistic

The effects of emotional trait factors on simulated flight performance under an acute psychological stress situation

Objective. Pilots are commonly exposed to some sources of emotional and cognitive stressors, especially for flight cadets, which have an important influence on flight safety. The present study aimed to study the relationship between emotional trait factors, emotional state, mental workload and simulated flight performance (SFP) under an acute psychological stress situation. Methods. Fifty-five undergraduates were included in the study. The Wong and Law emotional intelligence scale (WLEIS), state-trait anxiety inventory (STAI), stress rating questionnaire (SRQ) and National Aeronautics and Space Administration task load index (NASA-TLX) were used as data collection tools. Nine hours of simulated flight training were conducted in a simulator of the Type-6 Primary Trainer (Aviation University Air Force, China). The simulated flight assessment was taken as the acute psychological stressor. Results. SFP was negatively correlated with tensity and state anxiety. Emotional intelligence (EI) indirectly affected the SFP mediated by emotional state and workload, and emotional state had a mediating effect on the relationship between trait anxiety and SFP. Conclusions. The findings indicated that emotional trait factors (EI and trait anxiety) may indirectly affect SFP under an acute psychological stress situation, and emotional state (tensity and state anxiety) and mental workload played an important mediating role.

Weight watchers: NASA-TLX weights revisited

National Aeronautics and Space Administration Task Load Index (NASA-TLX) is a popular method to evaluate mental workload. NASA-TLX assesses mental workload across six load dimensions. When the dimensions are not assumed to be approximately equally important, they are weighted by conducting a pairwise comparison for every dimension pair, followed by the normalisation of weights reflecting the importance of the dimensions. This original NASA-TLX weighting method creates some challenges that are difficult to identify when the weights are being assigned. First, the original NASA-TLX weighting does not allow directly expressing two or more dimensions as equally important. Second, if pairwise comparisons are conducted consistently, there exists only one possible importance order for the dimensions. Third, with consistently conducted pairwise comparisons, a weight of 0.33 is artificially forced on the most important dimension. Swing and Analytic Hierarchy Process weighting methods for eliciting the weights of the dimensions are proposed as a solution to these challenges. The advantages of applying these methods in NASA-TLX are introduced theoretically and demonstrated empirically using data from virtual air combat simulations. The objective of this paper is to help scholars and practitioners to use NASA-TLX in mental workload assessments such that the discussed weighting issues are avoided.

Residents’ subjective mental workload during computerized prescription entry

ABSTRACT To examine residents’ subjective mental workload when they enter prescriptions in a computerized physician order entry (CPOE) system. Twenty-two residents completed six prescribing tasks in which two factors were manipulated: numerical input method and level of urgency. Data on demographic characteristics, familiarity with CPOE, and pretest performance were collected. The subjective mental workload was measured by the National Aeronautics and Space Administration-Task Load Index (NASA-TLX). Temporal demand (Mean = 34.48) contributed most to residents’ workload on the CPOE task, followed by Performance (Mean = 29.23). No significant associations were found between workload and demographic characteristics, CPOE familiarity, or pretest CPOE performance (p’s > .05). A 3 × 2 repeated-measures ANOVA yielded main effects of numerical input method [F (2, 19) = 88.358, p < .001, η2 = .900] and level of urgency [F (1, 21) = 169.654, p < .001, η2 = .890], and interaction of input method and urgency [F (2, 20) = 87.427, p < .001, η2 = .900]. Residents’ major sources of workload during the CPOE prescription were temporal demand and performance. Prescriptions entered by the row of numbers exhibited the highest workload. Workload increased with higher level of urgency. It is necessary to emphasize the negative impact of subjective workload, especially in prescription task under urgent situation. Further researches focus on medical staff’s workload are encouraged to ensure patient safety.