Challenges and promises of mixed-reality interventions in acquired brain injury rehabilitation: A scoping review

Background: Acquired brain injury (ABI) can lead to significant impairments and difficulties in everyday life, necessitating the need for rehabilitation. Mixed-reality (MR) technologies have revolutionized the delivery of neurorehabilitation therapies. However, inconsistencies in research methodology, diverse study populations and designs, and exaggerated claims in the research, media, and private consumer sectors have impacted the knowledge base of the field, including within the context of ABI rehabilitation. Objective: This scoping review aims to explore MR-systems in ABI rehabilitation, while assessing the evidence base and technology readiness levels of these systems. Methods: Seven databases were searched for studies, which were screened and analyzed by two independent raters. The types of MR systems, levels of evidence, and technology readiness levels were extracted and analyzed using descriptive analyses. Results: Twenty-six studies were included in the review, all of which focused on ABI etiologies stemming from strokes. Across studies, upper-limb motor rehabilitation was the most common rehabilitation target of MR interventions, followed by gait, cognition, and lower-extremity functioning. At present, overall results indicate low evidence for MR-applications in ABI rehabilitation, with a median technology readiness level of 6, corresponding to system prototypes being tested in relevant environments. Conclusion: Although challenges regarding system usability and design were reported, results appear promising with ongoing research. With variability across studies, technologies, and populations, determining the effectiveness of MR interventions in ABI remains a challenge, necessitating the need for ongoing innovation, research, and development of these systems.