Usability Evaluation of an Augmented Reality Sensorimotor Assessment Tool for Astronauts

Abstract

As next-generation space exploration missions require increased autonomy from astronaut crews, real-time diagnostics of astronaut health and performance are essential for mission operations, especially for determining Extravehicular Activity (EVA) readiness. Due to the disruption of the sensorimotor and neurovestibular systems in microgravity, astronauts exhibit significant impairments in their functional abilities that require distinct adaptation timelines. Physiological decrements can significantly affect operations during and shortly after gravity transitions, when performance risks are greatest. An Augmented Reality (AR) system may be a viable solution to the resource, volumetric, and time constraints of space operations by allowing holographic visual cueing to replace physical objects used in traditional Earth-based assessments. This paper presents the development and preliminary usability testing of a non-intrusive system that employs Augmented Reality and inertial measurement units (IMU) to evaluate sensorimotor and neurovestibular performance throughout mission timelines. The Augmented Reality Operations Readiness Assessment (AURORA) includes distinct assessments for static, dynamic, and operational balance and hand-eye coordination. During the AR development process of AURORA, human-in-the-loop usability experiments were conducted with first-time users (n=15) to gather feedback regarding the user interactions within the application. Usability questions were modeled after established usability surveys (e.g., SUS, NASA TLX) to probe for perceived ease of use, system capabilities, user interface readability, comfort, future use intention, and overall reactions to the system affordances. Thirteen participants reported that the system effectively described assessment requirements via animations and task instructions so they could self-administer assessments. Twelve participants reported their overall experience using the system as positive and rated the process of learning the hand gestures and operating the application as moderately and extremely easy. Questionnaire results indicate that the system has very strong potential for supporting self-administered physiological assessments while maintaining relatively low levels of mental and physical effort. Throughout the study several usability issues were discovered. Four participants struggled to properly execute the trained hand gestures and had issues with depth perception thereby limiting their ability to effectively interact with the system. Explorations into AR design and button interactions will be considered to support users who struggled with system interactions. Further training and instructional protocols will also be implemented to support users. Findings from the usability testing support recommendations for future designers of AR systems and the creation of a full beta version to support validation testing of the derived performance metrics. The research also lays the foundation for countermeasures development and AR training to mitigate impairments to astronauts' functional abilities that may impact operations.