Sensemaking, adaptation and agency in human-exoskeleton synchrony.

Introduction: Wearable I robots such as exoskeletons combine the strength and precision of intelligent machines with the adaptability and creativity of human beings. Exoskeletons are unique in that humans interact with the technologies on both a physical and cognitive level, and as such, involve a complex, interdependent relationship between humans and robots. The aim of this paper was to explore the concepts of agency and adaptation as they relate to human-machine synchrony, as human users learned to operate a complex whole-body powered exoskeleton. Methods: Qualitative interviews were conducted with participants over multiple sessions in which they performed a range of basic functional tasks and simulated industrial tasks using a powered exoskeleton prototype, to understand their expectations of the human-technology partnership, any challenges that arose in their interaction with the device, and what strategies they used to resolve such challenges. Results: Analysis of the data revealed two overarching themes: 1) Participants faced physical, cognitive, and affective challenges to synchronizing with the exoskeleton; and 2) they engaged in sensemaking strategies such as drawing analogies with known prior experiences and anthropomorphized the exoskeleton as a partner entity in order to adapt and address challenges. Discussion: This research is an important first step to understanding how humans make sense of and adapt to a powerful and complex wearable robot with which they must synchronize in order to perform tasks. Implications for our understanding of human and machine agency as well as bidirectional coadaptation principles are discussed.

Eye-Tracking in Physical Human-Robot Interaction: Mental Workload and Performance Prediction.

BACKGROUND: In Physical Human-Robot Interaction (pHRI), the need to learn the robot's motor-control dynamics is associated with increased cognitive load. Eye-tracking metrics can help understand the dynamics of fluctuating mental workload over the course of learning. OBJECTIVE: The aim of this study was to test eye-tracking measures' sensitivity and reliability to variations in task difficulty, as well as their performance-prediction capability, in physical human-robot collaboration tasks involving an industrial robot for object comanipulation. METHODS: Participants (9M, 9F) learned to coperform a virtual pick-and-place task with a bimanual robot over multiple trials. Joint stiffness of the robot was manipulated to increase motor-coordination demands. The psychometric properties of eye-tracking measures and their ability to predict performance was investigated. RESULTS: Stationary Gaze Entropy and pupil diameter were the most reliable and sensitive measures of workload associated with changes in task difficulty and learning. Increased task difficulty was more likely to result in a robot-monitoring strategy. Eye-tracking measures were able to predict the occurrence of success or failure in each trial with 70% sensitivity and 71% accuracy. CONCLUSION: The sensitivity and reliability of eye-tracking measures was acceptable, although values were lower than those observed in cognitive domains. Measures of gaze behaviors indicative of visual monitoring strategies were most sensitive to task difficulty manipulations, and should be explored further for the pHRI domain where motor-control and internal-model formation will likely be strong contributors to workload. APPLICATION: Future collaborative robots can adapt to human cognitive state and skill-level measured using eye-tracking measures of workload and visual attention.

Manufacturing Industry Stakeholder Perspectives on Occupational Exoskeletons: Changes after a Brief Exposure to Exoskeletons.

OCCUPATIONAL APPLICATIONSMultiple occupational exoskeletons have been developed recently with potential to reduce physical demands, muscle fatigue, and risk of over-exertion injuries in manufacturing, yet there are currently challenges in practical, large-scale deployment. We explored how stakeholder perceptions of exoskeletons were affected by exposure to passive arm- and back-support exoskeletons. Our outcomes indicate that even brief exposure to exoskeletons can positively influence worker and stakeholder perceptions on the usefulness and safety of exoskeletons. However, worker concerns about device usability and acceptability in the field were not mitigated by such brief exposure. This work may help manufacturing industry stakeholders understand what technology-adoption factors need further consideration when planning for exoskeleton deployment.

Background: Despite evidence from several laboratory studies on the effectiveness of passive exoskeletons to support specific industrial jobs, barriers to adoption still exist. Contextual factors underlying exoskeleton adoption need further understanding. Purpose: We aimed to document how stakeholder perceptions of exoskeleton technologies could be affected by physical exposure to a wide variety of exoskeletons, by providing an opportunity to wear them and perform standardized tasks. Methods: We recorded the opinions of 22 participants from different manufacturing industries, both before and after trying seven different passive arm-support and back-support occupational EXOs. EXO expectations, adoption factors/barriers in their work settings, and perceived next steps for implementing such technologies were captured. Participants also completed usability questionnaires after each EXO trial. Results: Even brief exposure to EXOs positively influenced both worker and stakeholder perceptions on exoskeleton usefulness and safety; in contrast, worker concerns about usability and acceptability remained unchanged. Participants indicated stronger preferences for some specific EXO technologies, in terms of ease of use, performance improvements, and applicability. Conclusions: Actual exposure to occupational exoskeletons, even if brief, was found to alter worker and stakeholder perceptions of exoskeleton usefulness and safety. Future work on technology perceptions and intention to use exoskeletons may need to consider physical exposure to devices before soliciting perceptions, especially for novel technologies like exoskeletons.