Comparison of two pupillometric measures as indicators of cognitive strain and under the influence of screen luminance.

The pupil diameter has been shown to provide insight to a person's experienced cognitive strain. Pupillary light responses, however, make this measure unreliable in uncontrolled settings. Two derived indicators-Index of Cognitive Activity (ICA) and Index of Pupillary Activity (IPA)-aim to 'eliminate' lighting influences, changing based only on the perceived cognitive strain. The IPA potentially offers a valuable alternative to the ICA through its fully transparent calculation, which lifts the restrictions to proprietary software and supported eye trackers. The measures are examined and compared based on two experimental studies; (i) as indicators of cognitive strain during mental arithmetic tasks and (ii) under different conditions of computer screen luminance. Results indicate that neither indicator differentiates between the increasing levels of cognitive strain. Differences in screen luminance are reflected in both indicators, although differently between the conditions. Both results contradict the claims of the indicators and further investigations are thus required.

Work interruptions of office workers: The influence of the complexity of primary work tasks on the perception of interruptions.

BACKGROUND: Research demonstrates that work interruptions are considered one of the most common work stressors. Understanding the mechanisms of work interruptions is therefore vital to reducing worker stress and maintaining performance. OBJECTIVE: The aim of this research is to investigate the influence of the frequency of work interruptions on subjective workload in the context of office work. Specifically, the mediating influence of interruption perception as well as the moderating influence of the complexity of the primary task are examined. METHOD: The work interruptions of 492 office workers in Germany were collected by means of a one-day diary study. A mediation model and a conditional indirect effect model were calculated to examine the influence of interruption frequency on subjective workload, mediated by the individual perception of these interruptions as well as moderated by the complexity of the primary work tasks. RESULTS: The analyses indicated a significant mediation and moderation. This implies that, on the one hand, the perception of work interruptions significantly mediates the relationship between the frequency of work interruptions and subjective workload. On the other hand, more complex primary work tasks seem to strengthen the positive relationship between interruption frequency and perceived interruption overload. CONCLUSION: The study underlines that work interruptions need to be considered in a much more differentiated way than is currently the case. Both in research and in terms of intervention measures in the work context, the various influencing factors need to be identified for an assessment of the effects on the working person to be possible.

Physiological measures of operators' mental state in supervisory process control tasks: a scoping review.

Physiological measures are often used to assess the mental state of human operators in supervisory process control tasks. However, the diversity of research approaches creates a heterogeneous landscape of empirical evidence. To map existing evidence and provide guidance to researchers and practitioners, this paper systematically reviews 109 empirical studies that report relationships between peripheral nervous system measures and mental state dimensions (e.g. mental workload, mental fatigue, stress, and vigilance) of interest. Ocular and electrocardiac measures were the most prominent measures across application fields. Most studies sought to validate such measures for reliable assessments of cognitive task demands and time on task, with measures of pupil size receiving the most empirical support. In comparison, less research examined the utility of physiological measures in predicting human task performance. This approach is discussed as an opportunity to focus on operators' individual response to cognitive task demands and to advance the state of research.

Physiological measures can provide the basis for dynamic operator assistance in supervisory process control tasks. This review synthesises the existing evidence, highlighting both the aggregated empirical support and the heterogeneity of the results. To advance the status quo, a larger emphasis on physiological measures as predictors of operator performance is needed.Abbreviations: HF/E: Human factors and ergonomics; CNS: Central nervous system; PNS: Peripheral nervous system; HR: Heart rate; HRV: Heart rate variability; IBI: Interbeat interval; AVNN: Average of RR intervals; SDRR: Standard deviation of RR intervals; CVRR: Coefficient of variation in RR intervals; RMSSD: Root mean square of successive; pNNX: Percentage of successive RR intervals; MAD: Median absolute deviation; LF: Power of the low-frequency; MF: Power of the mid-frequency; HF: Power of the high-frequency; TP: Total power.

Do multimodal search cues help or hinder teleoperated search and rescue missions?

In search and rescue missions, teleoperated rovers equipped with sensor technology are deployed into harsh environments to search for targets. To support the search task, unimodal/multimodal cues can be presented via visual, acoustic and/or haptic channels. However, human operators often perform the search task in parallel with the driving task, which can cause interference of attentional resources based on multiple resource theory. Navigating corners can be a particularly challenging aspect of remote driving, as described with the Cornering Law. Therefore, search cues should not interfere with cornering. The present research explores how unimodal/multimodal search cues affect cornering performance, with typical communication delays of 50 ms and 500 ms. One-hundred thirty-one participants, distributed into two delay groups, performed a target search task with unimodal/multimodal search cues. Search cues did not interfere with cornering performance with 50 ms delays. For 500 ms delays, search cues presented via the haptic channel significantly interfered with the driving task. Practitioner summary: Teleoperated rovers can support search and rescue missions. Search cues may assist the human operator, but they may also interfere with the task of driving. The study examined interference of unimodal and multimodal search cues. Haptic cues should not be implemented for systems with a delay of 500 ms or more.

Digital platforms: Perceived criteria of success, importance of work design, occupational safety and health for present and prospective digital platforms.

BACKGROUND: Digital platforms have found their way into all our lives: they are discussed in political, economic, scientific and public fields worldwide. Platform-based work is also on the rise in the German labour market, not only in institutionalised work, but also in start-ups and spin-offs. OBJECTIVES: The article describes the results of an analysis aimed at identifying perceptions of new and already known major success factors on market entry and market penetration regarding occupational safety and health (OSH) and work design. METHODS: A total of 31 semi-standardised interviews were conducted with 39 people. First, perceived success factors in general were examined with the comparative analysis. Surprisingly, OSH/work design factors did not emerge as perceived success factors. For this reason, a in-depth analysis was performed in a secondary analysis with the structured content analysis. RESULTS: Identified perceived success factors were user orientation, scalability, network effects, niche occupation. The in-depth secondary analysis with focus on OSH/work design showed that the interviewees are aware of the topic of OSH/work design, but did not consider it to be important to economic success. CONCLUSIONS: The identified success factors may not seem surprising. What is surprising, however, is the role played by OSH/work design. Solutions must be developed that sensitize working persons in the platform sector to the topic of OSH/work design. A two-step process may be useful: First, uniform regulations and laws must be anchored in the platform architecture. Second, various measures and training courses can be designed to inform and raise awareness.

Crisis Ahead? Why Human-Robot Interaction User Studies May Have Replicability Problems and Directions for Improvement.

There is a confidence crisis in many scientific disciplines, in particular disciplines researching human behavior, as many effects of original experiments have not been replicated successfully in large-scale replication studies. While human-robot interaction (HRI) is an interdisciplinary research field, the study of human behavior, cognition and emotion in HRI plays also a vital part. Are HRI user studies facing the same problems as other fields and if so, what can be done to overcome them? In this article, we first give a short overview of the replicability crisis in behavioral sciences and its causes. In a second step, we estimate the replicability of HRI user studies mainly 1) by structural comparison of HRI research processes and practices with those of other disciplines with replicability issues, 2) by systematically reviewing meta-analyses of HRI user studies to identify parameters that are known to affect replicability, and 3) by summarizing first replication studies in HRI as direct evidence. Our findings suggest that HRI user studies often exhibit the same problems that caused the replicability crisis in many behavioral sciences, such as small sample sizes, lack of theory, or missing information in reported data. In order to improve the stability of future HRI research, we propose some statistical, methodological and social reforms. This article aims to provide a basis for further discussion and a potential outline for improvements in the field.

Using IoT devices for sensor-based monitoring of employees' mental workload: Investigating managers' expectations and concerns.

Although the objective assessment of mental workload has been a focus of human factors research, few studies have investigated stakeholders' attitudes towards its implementation in real workplaces. The present study addresses this research gap by surveying N = 702 managers in three European countries (Germany, United Kingdom, Spain) about their expectations and concerns regarding sensor-based monitoring of employee mental workload. The data confirm the relevance of expectations regarding improvements of workplace design and employee well-being, as well as concerns about restrictions of employees' privacy and sovereignty, for the implementation of workload monitoring. Furthermore, Bayesian regression models show that the examined expectations have a substantial positive association with managers' willingness to support workload monitoring in their company. Privacy concerns are identified as a significant barrier to the acceptance of workload monitoring, both in terms of their prevalence among managers and their strong negative relationship with monitoring support.

Why cumulative loading calculated using non-weighted integration may not be suitable for assessing physical stress of the lower back: an empirical investigation of strain during lifting and lowering tasks.

When work-related physical stress is assessed using non-weighted integration, it is assumed that different loading conditions have a sufficiently comparable effect on the human body as long as the area under the loading curve is the same. Growing evidence cast doubt on whether this simple calculation can adequately estimate physical work-related strain. This study investigates in vivo, focussing on the lower back, whether the non-weighted method adequately reflects work-related physical strain of the lower back. Strain data resulting from lifting/lowering tasks performed in a laboratory study with an identical area under the loading curve but different load intensities were compared. Results showed that the non-weighted method does not sufficiently reflect the resulting muscular, cardiovascular and perceived strain but underestimates the influence of higher load intensity even in the range of medium physical exposure. Further research is needed regarding the determination of weighting factors and limit values. Practitioner Summary Given the dynamic nature of most physical work activities, the assessment of time-varying loading of the lower back is of particular interest in practice. Results show that the widely used non-weighted calculation method does not accurately reflect the resulting physical strain but underestimates the influence of higher load intensity.Abbreviations: MSD: musculoskeletal disorders; WMSD: work-related musculoskeletal disorders; KIM-LHC: Key Indicator Method Lifting, Holding, Carrying; RES: right erector spinae longissimus; LES: left erector spinae longissimus; HR: heart rate; RPE: rating of perceived exertion; EMG: surface electromyography; ECG: electrocardiography; SENIAM: Surface ElectroMyoGraphy for the Non-Invasive Assessment of Muscles; MVC: maximum voluntary contraction; ANOVA: analysis of variance; Std. error: standard error HIGHLIGHTSResults of this empirical investigation suggest that the widely used non-weighted calculation method is not fully suitable for calculating cumulative loading of the lower back.Even in the range of medium physical exposure the non-weighted calculation method does not accurately reflect the resulting strain on the human body but tends to underestimate the influence of higher load intensity due to higher external weight.Despite the same cumulative loading value obtained when using the non-weighted method, the resulting physical strain values are generally about 20-25% higher.The results may be used to further develop ergonomic assessment methods in order to avoid a misclassification of loading conditions and to prevent the risk of overexertion.

Accuracy of a markerless motion capture system for postural ergonomic risk assessment in occupational practice.

Established methods for postural ergonomic risk assessment in occupational practice are mostly time-consuming and need to be conducted by experts. Use of technology could improve postural ergonomic risk assessments with regard to time efficiency and accuracy. A study was conducted to assess the accuracy of a markerless motion capture system (Microsoft Kinect V2) compared to a marker-based motion capture system (Vicon Bonita). Angles of different body segments were analysed. The results show major inaccuracies of the markerless motion capture system for capturing axial trunk rotation (mean angular deviation of 14.04°) indicating that potential health risks could be underestimated. Combined working postures of axial trunk rotation and arm anteversion show issues with self-occlusion. Based on the findings, it is discussed whether the detected inaccuracies for axial trunk rotation are likely to lead to overestimation or underestimation of potential health risks when conducting an ergonomic risk assessment.

[Work design measures and solutions for dealing with the COVID-19 pandemic: A systematic analysis of work in the primary, secondary, and tertiary sectors in Germany]. / Maßnahmen und Lösungen zur Arbeitsgestaltung für den Umgang mit der COVID-19 Pandemie: Eine systematische Analyse der Arbeit im Primär­, Sekundär- und Tertiärsektor in Deutschland.

The demand to adapt the work processes to hygiene- and contact reduction requirements in order to curtail the spread of the COVID-19 pandemic in Germany has led to short-term and sometimes radical changes in companies and organizations. Based on 52 expert interviews with company and organization representatives, this research project analyzed which pandemic-related changes in the context of work occur on a supraregional and cross-sectoral level, how they are to be evaluated, and which new ways of working might also prove beneficial to companies after the pandemic. In line with existing studies, an increasing flexibilization of work location and working hours, an acceleration of the digitalization of work processes, and effects on leadership culture were identified. Other key experiences relate to the adaptation of internal and external communication processes and the operational handling of crisis-related challenges. Based on the results, good practices were derived in form of normative-narrative use-case based scenarios.Practical Relevance: Dealing with the COVID-19 pandemic has been the central challenge for many companies over the past year and a half. The presented results show measures that have been successfully implemented in practice to overcome the challenges posed by the crisis, as well as approaches for the future development of forms of work. The measures are contextualized by outlining necessary framework conditions and success factors, thus promoting transfer to other companies and sectors of the economy.

A meta-analytic review of the reliability of the Index of Cognitive Activity concerning task-evoked cognitive workload and light influences.

The Index of Cognitive Activity (ICA) was introduced as a promising pupillary workload measure for field investigations since, unlike pupil dilation, it is not affected by illumination. Recent studies have investigated the ICA for task-evoked cognitive workload with contradictory findings. However, few studies investigated the influence of illumination on the ICA. Therefore, to examine inconsistencies regarding the reliability for workload measurement and the effects of light, a meta-analysis was conducted based on a structured literature review. The meta-analysis considered k = 14 studies with a total sample size of N = 751 participants. Results showed significant effects for workload (r = 0.61) and light (r = 0.45) on the ICA. Since moderating effects were found for several between-study differences, it seems likely that different cognitive processes and settings affect the indicator and should be considered in empirical investigations. According to the findings, the ICA is a reliable indicator for task-evoked workload. However, light influences were found which indicates that evidence-based conclusions regarding the ICA's practical applicability require further research.

The Relationship Between Individual Coping and the Need to Have and Seek Health Information Among Older Adults: Exploratory Mixed Methods Study.

BACKGROUND: The need to have and seek information shapes the context of computing systems. When it comes to health, individual coping influences human behavior. Therefore, the relationship between individual coping and the need to have and seek health information plays a crucial role in the development of digital health systems. OBJECTIVE: This study aims to examine the relationship between individual coping and the need to have and seek health information among older adults. METHODS: Questionnaires and semistructured interviews investigated the health information need (HIN) and health information-seeking behavior (HISB) in relation to the individual coping strategies of 26 older Germans. RESULTS: The mean age of the interviewed group was 71 years (SD 7). Quantitatively, a trend was found for a negative correlation between the avoidance-oriented coping and HIN (rs=-0.37895; bias-corrected and accelerated bootstrap 95% BCa CI -0.730 to 0.092; P=.05). The qualitative results supported this finding. For some participants, information and exchange was part of dealing with their health situation, whereas others wanted to learn as little as possible to avoid a decline in their health status. The older adults acquired, collected, and exchanged paper-based health data to augment clinical information sources and support information exchange with professionals. CONCLUSIONS: Individual coping strategies are relevant for the design of digital health systems. They can support older adults in coping with their health situation, although it remains unclear how systems must be designed for people with an avoidance coping strategy to achieve the same acceptance.

The Index of Cognitive Activity - Eligibility for task-evoked informational strain and robustness towards visual influences.

Various researchers have proposed pupillometric indicators to assess a person's cognitive strain. However, to distinguish the variation of pupil light response from psychosensory pupil response in experimental field conditions is a challenge. The Index of Cognitive Activity (ICA) addresses this problem by wavelet separation. This research investigates the ICA's sensitivity for multiple level task-evoked cognitive activity and visual influences concerning informational work tasks. Objective and subjective measures assessed cognitive strain of participants (N = 22) during various tasks. In a first experiment, mental arithmetic tasks were used to induce different levels of cognitive activity. In a second experiment, influences of screen polarity and presentation of information were investigated (N = 18). The results indicate that eye metrics are rarely sensitive to slight variations in task difficulty. Moreover, the ICA is likely to be sensitive towards constant screen illumination and shows tendencies regarding changes in displayed information. Possible ramifications for the objective assessment of cognitive strain are discussed.

Prediction model of the effect of postural interactions on muscular activity and perceived exertion.

Musculoskeletal disorders are a prevalent disease in many Western countries. While a large number of ergonomic analyses and assessment methods are nowadays available, most current methods that assess exposure calculate overall risk scores of individual body segments without considering interaction effects of exposure variables. Therefore, a study was conducted that aimed at investigating and quantifying interaction effects of trunk inclination and arm lifting on ratings of perceived exertion (RPE) and muscle activity. A multiple regression model to predict musculoskeletal load under consideration of interaction effects was derived. The study revealed that there is a significant interaction effect of trunk inclination and arm lifting. Furthermore, final regression models explained variance in exposure variables in a range of R2 = 0.68 to R2 = 0.147 with a subset of two to three inputs. The predicative equations support the computer-based post-processing of sensor data. Practitioner summary: This article elaborates on the importance of interaction effects of working postures on assessment results of load. In practise, easy to-use-methods for an assessment of working postures are needed. Therefore, a regression model is derived, which facilitates the quantification of work load under consideration of interaction effects. The use of this regression model for the assessment of posture data gathered by range sensors is recommended. Abbreviations: RPE: rating of perceived exertion; MSD: musculoskeletal disorder; OWAS: ovako working posture analysing system; RULA: rapid upper limb assessment; LUBA: postural loading on the upper body assessment; REBA: rapid entire body assessment; OCRA: occupational repetitive action;S D: standard deviation; EMG: surface electromyography; LUT: left upper trapezius pars descendens; RUT: right upper trapezius pars descendens; LLT: left trapezius pars ascendens; RLT: right trapezius pars ascendens; LAD: left anterior deltoideus; RAD: right anterior deltoideus; LES: left erector spinae longissimus; RES: right erector spinae longissimus; SENIAM: surface electroMyoGraphy for the non-invasive assessment of muscles; MVC: maximum voluntary contraction; MANOVA: multivariate analysis of variance; ANOVA: analysis of variance; OLS: ordinary least squares; MANCOVA: multivariate analysis of covariance.

AMICAI: A Method Based on Risk Analysis to Integrate Responsible Research and Innovation into the Work of Research and Innovation Practitioners.

The integration of ethics into the day-to-day work of research and innovation (R&I) is an important but difficult challenge. However, with the Aachen method for identification, classification and risk analysis of innovation-based problems (AMICAI) an approach from an engineering perspective is presented that enables the integration of ethical, legal and social implications into the day-to-day work of R&I practitioners. AMICAI appears in particular capable of providing a procedural guidance for R&I practitioners based on a method established in engineering science, breaking down the object of consideration into partial aspects and prioritizing the innovation-based problems in dependence of potential risk. This enables the user to apply AMICAI continuously during all stages of the research and development (R&D) process and to analyze and choose between certain sociotechnical alternatives. In this way, problems that affect ethical, legal, and social aspects can be understood, reflected and considered in the mostly technically focused R&D process. The paper gives a general guidance about AMICAI by describing principles and assumptions, providing the steps of analysis and application aids, giving an example application, explaining the necessary adjustments of AMICAI compared to the methodical basis of failure mode, effects, and criticality analysis and discussing the advantages and limits. AMICAI's simple applications can stimulate interdisciplinary cooperation in the R&D process and be a starting point for the development of an "open RRI risk analysis platform" allowing society to evaluate innovation-based problems.

Survey-based personas for a target-group-specific consideration of elderly end users of information and communication systems in the German health-care sector.

BACKGROUND: In many countries, including Germany, older people are increasing in numbers, while fewer caregivers are available. A way to address the problem is to develop new medical assistance and monitoring systems that are operated by the elderly on their own, e.g. in-home aftercare systems. OBJECTIVE: The development of a set of eight data-based personas in terms of a best practice approach is presented. METHOD: "Personas" are an integral method of the user-centered design approach. They address the problem of incomplete knowledge of individual user behaviour by introducing archetypal user groups. Thus, personas can be used at an early stage of development to raise the awareness of developers to the needs, skills, and abilities of the elderly. Personas are also a cost-effective method and quickly and easily accessible. In order to guarantee representativeness the development of personas needs to occur based on a robust data set of a certain user group. RESULTS: This article presents the data-driven development of eight personas. The applied data set results from a nationwide questionnaire study on the elderly's use of information and communication technology, out of elderly people in Germany. The results will be presented in terms of best practice. CONCLUSION: To conclude, survey-based personas of older end users can play an important role in the research and development of innovative devices. APPLICATION: The personas presented in this paper can be used in research and development to raise awareness of the needs and demands of end users.

The Aachen Falls Prevention Scale: Multi-Study Evaluation and Comparison.

BACKGROUND: Fall risk assessment is a time-consuming and resource-intensive activity. Patient-driven self-assessment as a preventive measure might be a solution to reduce the number of patients undergoing a full clinical fall risk assessment. OBJECTIVE: The aim of this study was (1) to analyze test accuracy of the Aachen Falls Prevention Scale (AFPS) and (2) to compare these results with established fall risk assessment measures identified by a review of systematic reviews. METHODS: Sensitivity, specificity, and receiver operating curves (ROC) of the AFPS were calculated based on data retrieved from 2 independent studies using the AFPS. Comparison with established fall risk assessment measures was made by conducting a review of systematic reviews and corresponding meta-analysis. Electronic databases PubMed, Web of Science, and EMBASE were searched for systematic reviews and meta-analyses that reviewed fall risk assessment measures between the years 2000 and 2018. The review of systematic reviews was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement. The Revised Assessment of Multiple SysTemAtic Reviews (R-AMSTAR) was used to assess the methodological quality of reviews. Sensitivity, specificity, and ROC were extracted from each review and compared with the calculated values of the AFPS. RESULTS: Sensitivity, specificity, and ROC of the AFPS were evaluated based on 2 studies including a total of 259 older adults. Regarding the primary outcome of the AFPS subjective risk of falling, pooled sensitivity is 57.0% (95% CI 0.467-0.669) and specificity is 76.7% (95% CI 0.694-0.831). If 1 out of the 3 subscales of the AFPS is used to predict a fall risk, pooled sensitivity could be increased up to 90.0% (95% CI 0.824-0.951), whereas mean specificity thereby decreases to 50.0% (95% CI 0.42-0.58). A systematic review for fall risk assessment measures produced 1478 articles during the study period, with 771 coming from PubMed, 530 from Web of Science, and 177 from EMBASE. After eliminating doublets and assessing full text, 8 reviews met the inclusion criteria. All were of sufficient methodological quality (R-AMSTAR score ≥22). A total number of 9 functional or multifactorial fall risk assessment measures were extracted from identified reviews, including Timed Up and Go test, Berg Balance Scale, Performance-Oriented Mobility Assessment, St Thomas's Risk Assessment Tool in Falling Elderly, and Hendrich II Fall Risk Model. Comparison of these measures with pooled sensitivity and specificity of the AFPS revealed a sufficient quality of the AFPS in terms of a patient-driven self-assessment tool. CONCLUSIONS: It could be shown that the AFPS reaches a test accuracy comparable with that of the established methods in this initial investigation. However, it offers the advantage that the users can perform the self-assessment independently at home without involving trained health care professionals.

Investigation of observational methods assessing workload of static working postures based on surface electromyography.

BACKGROUND: A large number of different methods are available to identify and assess working postures. Although observation-based methods are most commonly used in practise, investigations showed different results regarding validity of such methods. OBJECTIVE: To investigate validity of one of the most commonly used observation-based assessment method in ergonomics, the Ovako Working Posture Analysing System (OWAS) and the European standard EN 1005-4 for evaluation of working postures, an experimental laboratory study was conducted. METHODS: Muscle activity was measured under combinations of static working postures of trunk inclination and shoulder flexion to compare these measurements and observation-based assessments according to OWAS and EN 1005-4. In order to investigate the magnitude of correspondence between muscle activity and observation-based assessments, Spearman rank correlation coefficients (rs) were calculated. RESULTS: Significant correlations were found between OWAS and muscle activity (range from rs2 = 0.17 rs2 = 0.55). Significant correlations were found between EN 1005-4 and muscle activity (range from rs2 = 0.34 to rs2 = 0.74). CONCLUSIONS: Results emphasise a need for further developments of observation-based methods, since the two investigated methods showed a variance of validity ranging from small to large. Such improvements may also form a better basis for the ergonomic improvement of working conditions in practise, which is highly necessary due to a constantly high prevalence of MSDs in the last decades.