Evaluation Techniques Used to Evaluate Extended Reality (XR) Head Mounted Displays (HMDs) Used In Healthcare: A Literature Review (Preprint)

<sec> <title>BACKGROUND</title> Extended Reality (XR) Head Mounted Displays (HMDs) and their applications within healthcare are undergoing rapid innovation. XR HMDs such as Meta (previously Oculus) Quest, HTC Vive and Microsoft HoloLens are used across different clinical pathways for the education and training of staff and students, and to improve healthcare experiences and empower patients. The primary aim of healthcare providers is to deliver safe and high-quality patient experiences. XR environments can provide spaces for relaxation, engaging experiences that can distract patients from pain and anxiety, and educational interventions that can inform patients on prevention and self-management of symptoms. In the domain of staff and students, XR provides an opportunity to practice skills and improve competencies, without the consequences of errors. Skills can be practiced, and performance can be accessed numerous times within immersive environments that replicate real-world scenarios, thereby improving knowledge retention. Significant literature exists on the applications and affordances of XR HMDs. However, there is potential to develop literature on the evaluation tools and metrics used to evaluate XR HMDs and experiences </sec> <sec> <title>OBJECTIVE</title> Literature reviewing the current evaluation practices used to evaluate XR HMDs in healthcare is lacking. XR incorporates multiple technologies such as Virtual Reality (VR) and Augmented Reality (AR), with devices that offer varied levels of experiences due to the hardware and software configurations. Furthermore, within healthcare XR HMDs are used to pursue a variety of different outcomes. These factors make it challenging to develop a best practice for evaluation guide, however, documenting the different evaluation practices may be beneficial for clinicians and educators who aim to use, evaluate, and potentially scale up XR. Addressing the current gaps and providing suggestions for improvement of evaluation practices are essential at this stage in XR development. </sec> <sec> <title>METHODS</title> This paper presents findings from 104 healthcare papers that have used XR HMDs in the domain of patients or healthcare staff/students. The search was conducted through the PubMed database. Findings from the search are grouped into two domains- healthcare staff and students, and patients. Evaluations are classified into three categories of- technology, process and outcomes. </sec> <sec> <title>RESULTS</title> Findings show wide use of custom metrics, generally with a qualitative focus in technology evaluations, specifically in healthcare workers/students domain. Validated quantitative scales are often used in outcome evaluations within both domains. However, antecedents to outcomes, such as presence and immersion and their implications on processes that nudge users toward the outcomes are not studied well. </sec> <sec> <title>CONCLUSIONS</title> There is space for development of evidence-based XR usability scales specifically relevant for different technologies- AR, VR and MR. Evaluations in selected literature do not compare multiple HMDs or experiences, provide longitudinal data, or perform economic investigations. Documented findings, along with limitations and suggestions for future can help healthcare management in investment decisions and help clinicians and researchers in the selection of evaluation tools and metrics. As evidence based XR literature grows, evaluation of underlying processes that lead to outcomes can be improved. </sec>