Evaluation of Augmented Reality and Wearable Sensors to Assess Neurovestibular and Sensorimotor Performance in Astronauts for Extravehicular Activity Readiness

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. Exposure to microgravity leads to changes in astronaut physiology such as loss of bone density and muscle mass, cardiovascular deconditioning, and the reorganization of sensorimotor integration that require distinct adaptation timelines. As astronauts transition from microgravity to gravity-rich environments (e.g., the Moon or Mars), sensorimotor impairment may affect their ability to perform mission-critical tasks such as landing procedures, capsule egress, and early EVA. To ensure mission success and astronaut safety, it is essential to identify sensorimotor impairment during missions. At present, no flight-ready tools are available for astronauts to assess their sensorimotor impairment throughout a mission, especially tools for which expert assistance is not needed. Current Earth-based assessments require extensive resources to administer and skilled clinicians to score and interpret the data. The development of lightweight, space-conscious assessments for astronauts transitioning between gravity environments is crucial to the success of future exploration missions. An Augmented Reality (AR) standalone system may be a viable solution by allowing holographic visual cueing to replace physical objects used in traditional assessments. AR headsets are easily deployable, enable the user to see their physical environment for safety in confined spaces, provide flexibility for new software integration, and are multifunctional for other mission tasks such as procedural guidance. The research focused on the development, usability testing, and evaluation of the Augmented Reality Operations Readiness Assessment (AURORA) to assess neurovestibular and sensorimotor performance with holographic visual cueing and integrated inertial measurement units.

The human-in-the-loop usability testing demonstrated positive perceptions of usability across two diverse age groups spanning current and future astronaut age demographics. Although usability concerns were identified with a subset of users, future design recommendations, such as proximity lighting for improved depth perception, are provided to promote self-administration for all users. While performance for the sensorimotor and vestibular assessments differed when compared to Earth-based standards and physical assessments, the research demonstrated the potential of AR as an assessment tool with the benefit of embedded sensors and onboard computing capabilities. The AR tool effectively quantified changes in hand-eye coordination performance as measured by accuracy, precision, error rate, throughput, and movement time with varying task difficulty. Users were able to successfully complete the tasks, yielding meaningful performance measures. When compared to the physical environment, AR led to altered user strategies, predominantly marked by increased task time, reduced head and torso movements, and increased head pitch amplitude aimed at enhancing hologram visibility due to the restricted field of view of the headset. User performance could have also been attributed to the novel environment for most users. AR-induced strategies resembled compensatory responses observed in astronauts after spaceflight and in vestibular patients, suggesting that AR would not exacerbate symptoms of motion sickness. These findings address gaps outlined in NASA’s Human Research Roadmaps and offer guidance for AR design within NASA’s Human Integration Design Handbook. The research advances AR's potential as a standalone assessment tool in evaluating astronaut performance throughout missions while considering spaceflight constraints. The implication of this research extends into applications for both the aerospace industry and the medical field as it relates to aging populations and individuals with balance and sensorimotor disorders.