Workload Ratings Research Articles

BlockLoader: A Comprehensive Evaluation Framework for Blockchain Performance Under Various Workload Patterns

Hyperledger Fabric is one of the most popular permissioned blockchain platforms widely adopted in enterprise blockchain solutions. To optimize and fully utilize the platform, it is desired to conduct a thorough performance analysis of Hyperledger Fabric. Although numerous studies have analyzed the performance of Hyperledger Fabric, three significant limitations still exist. First, existing blockchain performance evaluation frameworks rely on fixed workload rates, which fail to accurately reflect the performance of blockchain systems in real-world application scenarios. Second, the impact of extending the breadth and depth of endorsement policies on the performance of blockchain systems has yet to be adequately studied. Finally, the impact of node crashes and recoveries on blockchain system performance has yet to be comprehensively investigated. To address these limitations, we propose a framework called BlockLoader, which offers seven different distributions of load rates, including linear, single-peak, and multi-peak patterns. Next, we employ the BlockLoader framework to analyze the impact of endorsement policy breadth and depth on blockchain performance, both qualitatively and quantitatively. Additionally, we investigate the impact of dynamic node changes on performance. The experimental results demonstrate that different endorsement policies exert distinct effects on performance regarding breadth and depth scalability. In the horizontal expansion of endorsement policies, the OR endorsement policy demonstrates stable performance, fluctuating around 88 TPS, indicating that adding organizations and nodes has minimal impact. In contrast, the AND endorsement policy exhibits a declining trend in performance as the number of organizations and nodes increases, with an average decrease of 10 TPS for each additional organization. Moreover, the dynamic behaviour of nodes exerts varying impacts across these endorsement policies. Specifically, under the AND endorsement policy, dynamic changes in nodes significantly affect system performance. The TPS of the AND endorsement policy shows a notable decline, dropping from 79.6 at 100 s to 41.96 at 500 s, reflecting a reduction of approximately 47% over time. Under the OR endorsement policy, the system performance remains almost unaffected.

The Use of Heart Rate Measures to Evaluate Stress Levels among Air Traffic Controllers

This paper looks at the possibility of using a heart rate monitor to evaluate stress levels among Air Traffic Controllers (ATCOs). Air Traffic Control (ATC) service requires constant good planning, situation awareness, and always making sound decisions. A study was conducted on two ATCOs for three complete work cycles: the morning shift from 8 a.m. to 4 p.m., the afternoon shift from 4 p.m. to 12 a.m., and the night shift from 12 a.m. to 8 a.m. Both participants have different roles, with Subject A being a planner controller while Subject B is a radar controller. The study used the NASA Task Load Index (NASA-TLX) survey to collect the subjective workload rating and a heart rate monitor armband to measure the heart rate reading of an ATCO and then compare it with the number of aircraft within the controlled area. Two hypotheses were investigated: the first one is the relationship between the number of traffic and heart rate readings, and the second hypothesis is the relationship between the elapsed working time and heart rate reading. The Spearman correlation test has been used to determine these relationships. Based on the results, a p-value of less than 0.05 and a positive correlation indicates a significant relationship between the number of aircraft and heart rate readings for both subjects. Elapsed time and heart rate measurement, on the other hand, do not significantly correlate with a p-value greater than 0.05 and a negative correlation was produced for both subjects. The unweighted NASA-TLX workload measure confirmed the findings for Subject A but not for Subject B. This might be due to the different roles carried out by both subjects during the experiment. This shows that different work tasks resulted in different workload-induced factors. The results show a promising outcome of using a heart rate monitor to evaluate stress levels among ATCOs. However, more subjects were needed to enable the use of this concept for future purposes of measuring ATCO stress levels to manage workload.

Evaluating the effect of frigate hangar shape modifications on helicopter recovery using piloted flight simulation

Turbulent ship airwakes can present a major challenge for a pilot landing a helicopter to the ship. A recent study has proposed modifications to the hangar of a simple ship, the SFS2, to improve the air flow over the deck. To assess the effect of the proposed hangar modification on the helicopter and pilot, the unsteady air flow over the modified ship has been computed using time-accurate CFD, and then integrated with a full-motion flight simulator for a pilot to conduct deck landings to the original and modified ship geometries in wind speeds from 30 kt to 50 kt. The effectiveness of the proposed modification was assessed through pilot workload ratings for the landing task, and by recording pilot control inputs and helicopter states. The study has shown that there are some benefits from the hangar modifications. In the headwind the helicopter was deemed to be at the safe limit at 50 kt when operating to the original SFS2, while the limit was not reached in the 50 kt wind for the modified ship. In an oblique wind, the safe wind speed limit was found to be 40 kt for the original ship and 50 kt for the modified version. Although the improvements are not substantial, they do represent a positive outcome.

Holographic visual cues for mission task elements

AbstractMission task elements (MTEs) are commonly used to evaluate the handling qualities (HQs) of rotorcraft. However, the traditional approach of physical ground courses faces challenges due to evolving rotorcraft designs and flight profiles. Infrastructure limitations and lack of flexibility for research pose significant obstacles, particularly for high-speed tasks. The emergence of new air vehicles, such as eVTOLs in the civil sector and future vertical lift configurations in the military domain, requires an adapted visual cueing process for previously unaddressed mission profiles. This paper proposes an innovative solution: an augmented reality (AR) system utilizing a head-mounted display to create virtual MTE courses called holographic visual cues (HVCs). A piloted simulation campaign performed at DLR’s AVES simulator compares the effectiveness of HVCs with dome projection-based visual cues, evaluating the performance of the AR system. The study investigated the impact of holographic visual cues on pilot handling qualities, workload ratings, and task performance, finding that although these cues typically do not significantly alter pilot ratings, individual responses varied, highlighting both the technology’s potential and the need for further refinement.

External workload and cognitive performance of a tactical military scenario-based field exercise

IntroductionMilitary personnel must manage a multitude of competing physiological and cognitive stressors while maintaining high levels of performance. Quantifying the external workload and cognitive demands of tactical military field exercises...

Measuring aviator workload using EEG: an individualized approach to workload manipulation.

Measuring an operator's physiological state and using that data to predict future performance decrements has been an ongoing goal in many areas of transportation. Regarding Army aviation, the realization of such an endeavor could lead to the development of an adaptive automation system which adapts to the needs of the operator. However, reaching this end state requires the use of experimental scenarios similar to real-life settings in order to induce the state of interest that are able to account for individual differences in experience, exposure, and perception to workload manipulations. In the present study, we used an individualized approach to manipulating workload in order to account for individual differences in response to workload manipulations, while still providing an operationally relevant flight experience. Eight Army aviators participated in the study, where they completed two visits to the laboratory. The first visit served the purpose of identifying individual workload thresholds, with the second visit resulting in flights with individualized workload manipulations. EEG data was collected throughout both flights, along with subjective ratings of workload and flight performance. Both EEG data and workload ratings suggested a high workload. Subjective ratings were higher during the high workload flight compared to the low workload flight (p < 0.001). Regarding EEG, frontal alpha (p = 0.04) and theta (p = 0.01) values were lower and a ratio of beta/(alpha+theta) (p = 0.02) were higher in the baseline flight scenario compared to the high workload scenario. Furthermore, the data were compared to that collected in previous studies which used a group-based approach to manipulating workload. The individualized method demonstrated higher effect sizes in both EEG and subjective ratings, suggesting the use of this method may provide a more reliable way of producing high workload in aviators.

Assessment of Drivers' Mental Workload by Multimodal Measures during Auditory-Based Dual-Task Driving Scenarios.

Assessing drivers' mental workload is crucial for reducing road accidents. This study examined drivers' mental workload in a simulated auditory-based dual-task driving scenario, with driving tasks as the main task, and auditory-based N-back tasks as the secondary task. A total of three levels of mental workload (i.e., low, medium, high) were manipulated by varying the difficulty levels of the secondary task (i.e., no presence of secondary task, 1-back, 2-back). Multimodal measures, including a set of subjective measures, physiological measures, and behavioral performance measures, were collected during the experiment. The results showed that an increase in task difficulty led to increased subjective ratings of mental workload and a decrease in task performance for the secondary N-back tasks. Significant differences were observed across the different levels of mental workload in multimodal physiological measures, such as delta waves in EEG signals, fixation distance in eye movement signals, time- and frequency-domain measures in ECG signals, and skin conductance in EDA signals. In addition, four driving performance measures related to vehicle velocity and the deviation of pedal input and vehicle position also showed sensitivity to the changes in drivers' mental workload. The findings from this study can contribute to a comprehensive understanding of effective measures for mental workload assessment in driving scenarios and to the development of smart driving systems for the accurate recognition of drivers' mental states.

Reasons behind Sleep Deprivation among Adolescents: Evidence from Beijing

Although current studies have examined the association between multiple variables and sleep deprivation among adolescents, such as the use of electronic devices and stress, few studies managed to disassociate the variables and examine the impact of each one on sleep individually. The objective of this study is to examine which factor between the use of electronic devices, workload, stress and basic psychological needs of an individual has the most impact on sleep duration and quality of adolescents. 16 participants volunteered for this research measuring their sleep and deep sleep through commercially available smart band provided. They self-reported the sleep data recorded along with the amount of time spent on electronic devices and schoolwork, and a rating of workload and stress on a scale of 1-10 through a period of 38 days. Participants then completed a Pittsburgh Sleep Quality Index questionnaire and a Self-Determination Theory questionnaire. Results show that stress has the most impact on both sleep duration and quality. The fulfillment of an individual’s psychological needs highly correlates with sleep: the unmet psychological needs directly influence other variables such as stress level which will affect sleep. This research shows inconsistency during data analysis when different method is applied potentially due to time constrain of this research, future research is needed to prove the validity of the finding.

11 The Moderating Effect of Depression on Workload Perception in Traumatic Brain Injury

Objective:Individuals who have experienced traumatic brain injury (TBI) are at an elevated risk for worsened physical and psychological outcomes. Increased rates of anxiety and depression, along with cognitive issues, are common post-TBI. While there is some evidence that anxiety and depression may affect objective cognitive performance, less is known about their effect on other factors that are associated with the individual’s capacity to complete the task, such as perceived workload of the cognitive task. Workload represents an individual’s perception of task difficulty and serves as a proxy for the magnitude of mental demands a given task places on an individual. Preliminary findings in the literature suggest that individuals with TBI commonly report greater workload when completing cognitive tasks compared to neurotypical peers, but the influence of anxiety and depression on survivors’ workload remains unclear. Considering the elevated rates of psychological and cognitive problems in individuals with TBI, the present study examined the moderating role of anxiety and depression on TBI survivor workload perception of a stress-inducing working memory task.Participants and Methods:Ten participants with moderate to severe TBI and eight neurologically healthy controls performed the Paced Auditory Serial Addition Task (PASAT). After completing the PASAT, participants reported their subjective workload using the NASA task load index (NASA-TLX). Participants also completed measures of psychological functioning, including the Chicago Multiscale Depression Inventory (CMDI) and the State-Trait Anxiety Inventory (STAI). Relationships between workload and depression and trait anxiety were examined using linear regression.Results:Linear regression was employed for both the TBI and the healthy control groups to assess the influence of trait anxiety and depression on perceived workload. There was no significant difference between the TBI and HC NASA perceived workload scores. Within the TBI group, there was a significant anxiety by depression interaction (b = -.015, p &lt; .001). Simple slopes analyses revealed that for TBI participants reporting low depression, perceived workload increased with increased anxiety (b = .093, p &lt; .001). For TBI participants reporting high depression, perceived workload decreased as anxiety increased (b = -.38, p = .03). While there was also significant anxiety by depression interaction in the healthy control group (b = .033, p = .04), simple slopes analyses revealed that there were no significant associations for healthy controls.Conclusions:These results demonstrate that in TBI, level of depression moderates the relationship between anxiety and workload perception. The pattern observed in the TBI group was unique from controls. The present findings suggest that post-TBI, higher depression may temper the influence of anxiety on stressful cognitive task performance and workload rating. The tempering effect of high depression in TBI may represent a biased reporting style or impaired assessment of task difficulty, which may ultimately affect the individual’s capacity to accomplish a task well.

56 Dunning-Kruger Effect and Anxiety in a Mexican population

Objective:The Dunning-Krueger effect is a cognitive bias where individuals tend to overestimate their abilities in areas where they are less competent. The Cordoba Naming Test (CNT) is a 30-item confrontation naming task. Hardy and Wright (2018) conditionally validated a measure of perceived mental workload called the NASA Task Load Index (NASA-TLX). Researchers reported that workload ratings on the NASA-TLX increased with increased task demands on a cognitive task. Anxiety is known as an emotion that can make an individual more susceptible to develop a mental health condition. We examine if the Dunning-Krueger effect occurs in a Mexican population with and without current symptoms of anxiety and possible factors driving individuals to overestimate their abilities on the CNT. We predicted the abnormal symptoms of anxiety (ASA) group would report better CNT performance, report higher perceived workloads on the CNT, and underperform on the CNT compared to the normal symptoms of anxiety (NSA) group. We also predicted the low-performance group would report better CNT performance, report higher perceived workloads on the CNT, and underperform on the CNT compared to the high-performance group.Participants and Methods:The sample consisted of 192 Mexican participants with NSA (79 low-performance &amp; 113 high-performance) and 74 Mexican participants with ASA (44 low-performance &amp; 30 high-performance). Participants completed the CNT, NASA-TLX, and the Hospital Anxiety and Depression Scale (HADS) in Spanish. The NASA-TLX was used to evaluate perceived workloads after the completion of the CNT. Meanwhile, the HADS was used to create our anxiety groups. Finally, CNT raw scores were converted into T-scores, which then were averaged to create the following two groups: low-performance (CNT T-Score &lt;50) and high-performance (CNT T-Score 50+). A series of 2x2 ANCOVAs, controlling for gender were used to evaluate CNT performance and perceived workloads.Results:We found a significant interaction where the low-performance ASA and the high-performance NSA groups demonstrated better CNT performance and reported higher perceived workloads (i.e., performance, temporal demand) on the CNT compared to their respective counterparts (i.e., low-performance NSA &amp; high-performance ASA groups), p's&lt;.05, ηp's2=.02. We found a main effect where the high-performance group outperformed the low-performance group on the CNT and reported lower perceived workloads on the CNT, p's&lt;.05, ηp's2 =.04-.46.Conclusions:The Dunning-Krueger effect did not occur in our sample. Participants that demonstrated better CNT performance also reported higher perceived workloads regardless of their current symptoms of anxiety. A possible explanation can be our sample's cultural norms of what would be considered as abnormal symptoms of anxiety, is a normal part of life, decreasing the possibilities to experience self-efficacy distoritions. Future studies should investigate whether the Dunning-Kruger effect may be influencing other aspects of cognitive functioning subjectively in Mexicans residing in Mexico and the United States with and without current symptoms of anxiety.

39 Perceived Workload and Language Order Effects on the Cordoba Naming Test in Spanish-English Bilinguals

Objective:The Cordoba Naming Test (CNT) is a 30-item confrontation naming task. The administration of the CNT can be administered in multiple languages. Hardy and Wright (2018) conditionally validated a measure of perceived mental workload called the National Aeronautic Space Administration Task Load Index (NASA-TLX). They found that workload ratings on the NASA-TLX increased with increased demands on a cognitive task. Researchers found interactions in a study examining language proficiency and language (i.e., in which the test was administered) on several tasks of the Golden Stroop Test. Their results revealed that unbalanced bilinguals’ best-spoken language showed significantly better results compared to balanced bilinguals’ where language use did not matter. To our knowledge, no study has examined the order effects of Spanish-English bilingual speakers’ CNT performance and perceived workloads when completed in Spanish first compared to English second and vice-versa. We predicted that persons that completed the CNT in English first would demonstrate better performances and report lower perceived workloads on the CNT compared to completing the CNT in Spanish second. In addition, we predicted that persons that completed the CNT in Spanish first would demonstrate worse performance and higher perceived workloads on the CNT compared to completing the CNT in English second.Participants and Methods:The sample consisted of 62 Spanish-English healthy and neurologically bilingual speakers with a mean age of 19.94 (SD= 3.36). Thirty-seven participants completed the CNT in English first and then in Spanish (English-to-Spanish) and 25 participants completed the CNT in Spanish first and then in English (Spanish-to-English). The NASA-TLX was used to evaluate CNT perceived workloads. All the participants completed the NASA-TLX in English and Spanish after completing the CNT in the language given, respectfully. A series of paired-samples T-Tests were completed to evaluate groups CNT performance and perceived workload.Results:We found that the English-to-Spanish group performed better on the CNT in English first than completing it in Spanish second, p = .000. We also found that the English-to-Spanish group reported better performance and less mentally demanding on the CNT when it was completed in English first compared to completing it in Spanish second, p’s &lt; .05. Regarding the Spanish-to-English group, we found participants performed worse when they completed the CNT in Spanish first compared to completing the CNT in English second, p = .000. Finally, the Spanish-to-English group reported worse performance completing the CNT in Spanish first, more temporal demanding, and more frustrating compared to completing the CNT in English second, p’s &lt; .05.Conclusions:As expected, when participants completed the CNT in English, regardless of the order, they performed better and reported lower perceived workloads compared to completing the CNT in Spanish. Our data suggests that language order effect influenced participants CNT performance possibly due to not knowing specific items in Spanish compared to in English. Future studies using larger sample sizes should evaluate language order effects on the CNT in Spanish-English balanced bilingual speakers compared to unbalanced bilingual speakers.

Anticipatory information makes the difference: Behavioral effects and user assessments of a cyclist warning system to enhance cyclists’ situation awareness

Problem: Increasing numbers of crashes involving pedelecs, and particularly older pedelec users, induce a need to enhance cycling safety. We evaluated a prototype cyclist warning system (CWS) that aims to increase situation awareness (SA) by alerting to safety critical events (SCE) with trimodal (auditory, visual, tactile). Method: To investigate the effects of CWS usage, we conducted a 2x2 mixed design bicycle simulator study with factors (1) CWS usage (within: rides WITH vs. WITHOUT CWS) and (2) age group (between: younger vs. older cyclists) on braking reaction time, gaze behavior, mental workload, and perceived safety. In sum, N = 64 participants (n = 32 younger, 18–40 years; n = 32 older, ≥ 55 years) took part in the study and experienced two balanced blocks of short rides including SCE of particular relevance for cycling safety. Results: CWS usage resulted in earlier braking reactions to all investigated SCE and partly earlier fixation on the critical interaction partners (CIP) indicating increased cyclists’ SA. Consistently to behavioral measures, participants’ assessments regarding perceived safety further supported the safety improvements derived from CWS independently of age group. Moreover, CWS usage did not add to mental workload ratings. Age effects were selectively found for gaze data showing that across all SCE, older adults fixated longer and more frequently on street alignment, and less frequently on other road users. Discussion: Taken together, the CWS evaluation showed promising results indicating the potential of the tested CWS to increase SA and enhance cyclists’ safety both on a behavioral level and regarding subjective assessments. Further research should address the systems’ safety potential under real-world conditions and for situations of higher complexity. Practical Applications: Understanding the potential impact of road safety measures such as CWS is important to contribute effectively to reducing SCE.

Measuring Emergency Department Workload Perception Using Electronic Medical Record Measures of Patient Volume and Acuity

BackgroundWorkload in the emergency department (ED) fluctuates and there is no established model for measurement of clinician-level ED workload. ObjectiveThe aim of this study was to measure perceived ED workload and assess the relationship between perceived workload and objective measures of workload from the electronic medical record (EMR). MethodsThis study was conducted at a tertiary care, academic ED from July 1, 2020 through April 13, 2021. Attending workload perceptions were collected using a 5-point scale in three care areas with variable acuity. We collected eight EMR measures thought to correlate with perceived workload. EMR values were compared across areas of the department using ANOVA and correlated with attending workload ratings using linear regression. ResultsWe collected 315 unique workload ratings, which were normally distributed. For the entire department, there was a weak positive correlation between reported workload perception and mean percentage of inpatient admissions (r = 0.23; p < 0.001), intensive care unit admissions (r = 0.2; p < 0.001), patient arrivals per shift (r = 0.14; p = 0.017), critical care billed visits (r = 0.22; p < 0.001), cardiopulmonary resuscitation code activations (r = 0.2; p < 0.001), and level 5 visits (r = 0.13; p = 0.02). There was weak negative correlation for ED discharges (r = –0.23; p < 0.001). Several correlations were stronger in individual care areas, including percent admissions in the lowest-acuity area (r = 0.43; p = 0.033) and patient arrivals in the highest-acuity area (r = 0.44; p < .01). No significant correlation was found in any area for observation admissions or trauma activations. ConclusionsIn this study, EMR measures of workload were not closely correlated with ED attending physician workload perception. Future study should examine additional factors contributing to physician workload outside of the EMR.

Mental health and current issues of migrant workers in Japan: A cross-sectional study of Vietnamese workers.

Over the past 5 years, the number of Vietnamese migrant workers in Japan has grown rapidly to become the largest group of migrant workers in the country. They hold various statuses of residence and are subjected to multifactorial stressors. The current study's aim is to investigate the association between psychological distress experienced by Vietnamese workers and their work environment. Another aim is to discuss issues involving migrant workers by comparing the characteristics of workers in the major statuses of residence. The study applied a cross-sectional design, and included a nationwide self-administered online questionnaire that was conducted in Vietnamese in 2022. The questionnaire included the Kessler Psychological Distress Scale (K10), workplace interpersonal factors as well as factors related to work and health. A multiple logistic regression analysis was conducted to investigate factors associated with psychological distress. Of 933 Vietnamese workers, 37% were grouped as distressed under the K10 cutoff. Fewer opportunities to speak with Japanese co-workers, lower welfare and workload ratings, and the visa statuses including 'Technical Intern Training' were significantly associated with psychological distress. Unexpectedly, those in 'Engineer/Specialist in Humanities/International Services (ESI)' category who are deemed to hold better conditions demonstrated the highest amounts of distress. Outside of unsatisfactory working environments, differing situations depending on status of residence could produce various sources of distress. The difficult aspects of Japan's distinct culture seem to contribute to their distress, especially for those who have more interactions with Japanese co-workers. A push for a multicultural society, where migrant workers can pursue proactive life designs of their own choosing, is warranted.

Lower Executive Function Ability May Lead to Higher Perceived Mental Workload in Driving Scenarios

Driver mental workload may represent a mismatch between task demands and available mental resources. If driving mental workload arises from a mismatch involving executive functions, then drivers with more executive function ability should perceive less mental workload in driving situations. To test this hypothesis, 33 participants rated the mental workload associated with 16 driving scenarios and also carried out three cognitive assessment games designed to measure executive functions (response inhibition, working memory updating, switching/shifting). We found a significant relationship between two of the executive function abilities (response inhibition, and switching/shifting, but not working memory updating) and mental workload ratings. With an increase in the age of participants, we observed lower response inhibition and higher perceived mental workload after viewing representations of driving scenarios. These results demonstrate that previous results showing higher perceived mental workload for older drivers may be, at least partly, due to decreases in executive function ability as people age.

Impact of Navigation Aid and Spatial Ability Skills on Wayfinding Performance and Workload in Indoor-Outdoor Campus Navigation: Challenges and Design

Wayfinding is important for everyone on a university campus to understand where they are and get to where they want to go to attend a meeting or a class. This study explores the dynamics of mobile navigation apps and the spatial ability skills of individuals on a wayfinding performance and perceived workload on a university campus wayfinding, including indoor-outdoor navigation, by focusing on three research objectives. (1) Compare the effectiveness of Google Maps (outdoor navigation app) and MazeMap (indoor-outdoor navigation app) on wayfinding performance and perceived workload in university campus wayfinding. (2) Investigate the impact of participants’ spatial ability skills on their wayfinding performance and perceived workload regardless of the used navigation app. (3) Highlight the challenges in indoor-outdoor university campus wayfinding using mobile navigation apps. To achieve this, a controlled experiment was conducted with 22 participants divided into a control (using Google Maps) and an experiment group (using MazeMap). Participants were required to complete a time-bound wayfinding task of navigating to meeting rooms in different buildings within the Gløshaugen campus of the Norwegian University of Science and Technology in Trondheim, Norway. Participants were assessed on spatial ability tests, mental workload, and wayfinding performance using a questionnaire, observation notes and a short follow-up interview about the challenges they faced in the task. The findings reveal a negative correlation between overall spatial ability score (spatial reasoning, spatial orientation, and sense of direction) and perceived workload (NASA TLX score and Subjective Workload Rating) and a negative correlation between sense of direction score and total hesitation during wayfinding task. However, no significant difference was found between the Google Maps and the MazeMap group for wayfinding performance and perceived workload. The qualitative analysis resulted in five key challenge categories in university campus wayfinding, providing implications for designing navigation systems that better facilitate indoor-outdoor campus navigation.

Robotic arm training in neurorehabilitation enhanced by augmented reality – a usability and feasibility study

BackgroundRobotic therapy and serious gaming support motor learning in neurorehabilitation. Traditional monitor-based gaming outputs cannot adequately represent the third dimension, whereas virtual reality headsets lack the connection to the real world. The use of Augmented Reality (AR) techniques could potentially overcome these issues. The objective of this study was thus to evaluate the usability, feasibility and functionality of a novel arm rehabilitation device for neurorehabilitation (RobExReha system) based on a robotic arm (LBR iiwa, KUKA AG) and serious gaming using the AR headset HoloLens (Microsoft Inc.).MethodsThe RobExReha system was tested with eleven adult inpatients (mean age: 64.4 ± 11.2 years; diagnoses: 8 stroke, 2 spinal cord injury, 1 Guillain-Barré-Syndrome) who had paretic impairments in their upper limb. Five therapists administered and evaluated the system. Data was compared with a Reference Group (eleven inpatients; mean age: 64.3 ± 9.1 years; diagnoses: 10 stroke, 1 spinal cord injury) who trained with commercially available robotic therapy devices (ArmeoPower or ArmeoSpring, Hocoma AG). Patients used standardized questionnaires for evaluating usability and comfort (Quebec User Evaluation of Satisfaction with assistive technology [QUEST]), workload (Raw Task Load Index [RTLX]) and a questionnaire for rating visual perception of the gaming scenario. Therapists used the QUEST, the System Usability Scale and the short version of the User Experience Questionnaire.ResultsTherapy with the RobExReha system was safe and feasible for patients and therapists, with no serious adverse events being reported. Patients and therapists were generally satisfied with usability. The patients’ usability ratings were significantly higher in the Reference Group for two items of the QUEST: reliability and ease of use. Workload (RTLX) ratings did not differ significantly between the groups. Nearly all patients using the RobExReha system perceived the gaming scenario in AR as functioning adequately despite eight patients having impairments in stereoscopic vision. The therapists valued the system’s approach as interesting and inventive.ConclusionsWe demonstrated the clinical feasibility of combining a novel robotic upper limb robot with an AR-serious game in a neurorehabilitation setting. To ensure high usability in future applications, a reliable and easy-to-use system that can be used for task-oriented training should be implemented.Trial registrationEthical approval was obtained and the trial was registered at the German Clinical Trials Register (DRKS00022136).

Air traffic controller workload level prediction using conformalized dynamical graph learning

Air traffic control (ATC) is a safety-critical service system that demands constant attention from ground air traffic controllers (ATCos) to maintain daily aviation operations. The workload of the ATCos can have negative effects on operational safety and airspace usage. To avoid overloading and ensure an acceptable workload level for the ATCos, it is important to predict the ATCos’ workload accurately for mitigation actions. In this paper, we first perform a review of research on ATCo workload, mostly from the air traffic perspective. Then, we briefly introduce the setup of the human-in-the-loop (HITL) simulations with retired ATCos, where the air traffic data and workload labels are obtained. The simulations are conducted under three Phoenix approach scenarios while the human ATCos are requested to self-evaluate their workload ratings (i.e., low-1 to high-7). Preliminary data analysis is conducted. Next, we propose a graph-based deep-learning framework with conformal prediction to identify the ATCo workload levels. The number of aircraft under the controller’s control varies both spatially and temporally, resulting in dynamically evolving graphs. The experiment results suggest that (a) besides the traffic density feature, the traffic conflict feature contributes to the workload prediction capabilities (i.e., minimum horizontal/vertical separation distance); (b) directly learning from the spatiotemporal graph layout of airspace with graph neural network can achieve higher prediction accuracy, compare to hand-crafted traffic complexity features; (c) conformal prediction is a valuable tool to further boost model prediction accuracy, resulting a range of predicted workload labels. The code used is available at Link.

Dual-tasking while using two languages: Examining the cognitive resource demands of cued and voluntary language production in bilinguals.

The way bilinguals switch languages can differ depending on the context. In cued dual-language environments, bilinguals select a language in response to environmental cues (e.g., a monolingual conversation partner). In voluntary dual-language environments, bilinguals communicating with people who speak the same languages can use their languages more freely. The control demands of these types of language-production contexts, and the costs of language switches, have been argued to differ (Adaptive Control Hypothesis). Here, we used a dual-task paradigm to examine how cued and voluntary bilingual production differ in cognitive resources used. Forty Mandarin-English bilinguals completed two language-switching paradigms as the primary task; one in response to cues and one while using two languages freely. At the same time, they also had to respond to the pitch of tones (secondary task). Response times (RTs) on the secondary task, as well as naming times on the primary task, were shorter under the voluntary- than cued-naming condition. Task workload ratings were also higher under the cued- than voluntary-naming condition. This suggests more attentional resources are needed in a cued-naming context to monitor cues and select languages accordingly. However, the costs associated with switching from one language to the other were similar in both voluntary- and cued-naming contexts. Thus, while cued-naming might be more effortful overall, cued and voluntary switching recruited similar levels of cognitive resources.

A robotic system for solo surgery in flexible ureteroscopy: development and evaluation with clinical users

PurposeThe robotic system CoFlex for kidney stone removal via flexible ureteroscopy (fURS) by a single surgeon (solo surgery, abbreviated SSU) is introduced. It combines a versatile robotic arm and a commercially available ureteroscope to enable gravity compensation and safety functions like virtual walls. The haptic feedback from the operation site is comparable to manual fURS, as the surgeon actuates all ureteroscope DoF manually.MethodsThe system hardware and software as well as the design of an exploratory user study on the simulator model with non-medical participants and urology surgeons are described. For each user study task both objective measurements (e.g., completion time) and subjective user ratings of workload (using the NASA-TLX) and usability (using the System Usability Scale SUS) were obtained.ResultsCoFlex enabled SSU in fURS. The implemented setup procedure resulted in an average added setup time of 341.7 ± 71.6 s, a NASA-TLX value of 25.2 ± 13.3 and a SUS value of 82.9 ± 14.4. The ratio of inspected kidney calyces remained similar for robotic (93.68 %) and manual endoscope guidance (94.74 %), but the NASA-TLX values were higher (58.1 ± 16.0 vs. 48.9 ± 20.1) and the SUS values lower (51.5 ± 19.9 vs. 63.6 ± 15.3) in the robotic scenario. SSU in the fURS procedure increased the overall operation time from 1173.5 ± 355.7 s to 2131.0 ± 338.0 s, but reduced the number of required surgeons from two to one.ConclusionsThe evaluation of CoFlex in a user study covering a complete fURS intervention confirmed the technical feasibility of the concept and its potential to reduce surgeon working time. Future development steps will enhance the system ergonomics, minimize the users’ physical load while interacting with the robot and exploit the logged data from the user study to optimize the current fURS workflow.