  The emergence of virtual companions is transforming the evolution of
intelligent systems that effortlessly cater to the unique requirements of
users. These advanced systems not only take into account the user present
capabilities, preferences, and needs but also possess the capability to adapt
dynamically to changes in the environment, as well as fluctuations in the users
emotional state or behavior. A virtual companion is an intelligent software or
application that offers support, assistance, and companionship across various
aspects of users lives. Various enabling technologies are involved in building
virtual companion, among these, Augmented Reality (AR), and Virtual Reality
(VR) are emerging as transformative tools. While their potential for use in
virtual companions or digital assistants is promising, their applications in
these domains remain relatively unexplored. To address this gap, a systematic
review was conducted to investigate the applications of VR, AR, and MR
immersive technologies in the development of virtual companions. A
comprehensive search across PubMed, Scopus, and Google Scholar yielded 28
relevant articles out of a pool of 644. The review revealed that immersive
technologies, particularly VR and AR, play a significant role in creating
digital assistants, offering a wide range of applications that brings various
facilities in the individuals life in areas such as addressing social
isolation, enhancing cognitive abilities and dementia care, facilitating
education, and more. Additionally, AR and MR hold potential for enhancing
Quality of life (QoL) within the context of virtual companion technology. The
findings of this review provide a valuable foundation for further research in
this evolving field.
