# Serious Games and Mixed Reality Applications for Healthcare
###### Abstract  
The goal of the research is to investigate the level of interactivity of the application and the motivation of the user, allowing adaptation to the user's level of competence, flexibility over time, repeatability, and continuous feedback. In recent years, there has been a growing interest in applying virtual reality (VR) techniques to the development of serious games for creating immersive experiences. VR and augmented reality (AR) have a long history in the healthcare sector, offering the opportunity to develop a wide range of tools and applications aiming at improving the quality of care and efficiency of services for professionals and patients alike. The best-known examples of VR/AR applications in the healthcare domain include surgical planning and medical training by means of simulation technologies. The techniques used in surgical simulation have also been applied to cognitive and motor rehabilitation, pain management, and patient and professional education. Recently, healthcare has also become one of the biggest adopters of mixed reality (MR), which merges real and VR content to generate new environments where physical and digital objects not only co-exist but are also capable of interacting with each other in real time. MR encompasses both VR and AR applications. These novel applications are attracting growing attention from users and researchers, but many cognitive and perceptual issues still need to be completely understood and resolved to fully take advantage of the disruptive potential of these emerging technologies in healthcare, and to minimize side effects of VR/AR technologies such as \"cybersickness\". Moreover, efforts should be made to strengthen the experience of \"presence\", the level of acceptance, and the compatibility of MR technology with the general population (including the elderly and sick people). In light of the above, this Special Issue was introduced to gather and publish original scientific contributions that explore opportunities and address the challenges of serious games, VR/AR, and MR applications in healthcare. There were 11 papers submitted to this Special Issue, and 8 papers were accepted. 20221236442022236420223642022364202236420236  
The collected papers cover some of the key points in the development of serious games, namely: development of interactive and engaging tasks to increase user motivation, acquisition and analysis of quantitative data, and adaptation to the user's conditions. In [PERSON] et al. [4], VR is proposed as a new assisting tool for patients suffering from macular degeneration. More specifically, a VR game that involves tracking and detecting changes in a moving object is proposed to re-define traditional tasks used for preferred retinal locus development studies and therapy, which can be repetitive, exhaustive, and tedious, ending in a decrease in the subject's motivation. Gamification, in this context, was intended to develop more entertaining tasks, resulting in greater participant engagement and rapid adaptation. One of the possibilities offered by serious games for rehabilitation/training is the collection and analysis of quantitative data for different purposes, such as: to assess the initial disease state and/or exercise performance, and to monitor the patient's progress during therapy, just to name a few. Three papers of this collection [1, 3, 5] focus on collecting and analyzing quantitative data, and two of them [1, 3] employ artificial intelligence (AI) techniques. AI is becoming an important major asset for serious games to provide more facilities for the learner, but also more knowledge for the supervisor (educator, medical specialist, etc.) [7]. [PERSON] et al. [3] describe the integration of biofeedback into a serious game to monitor frailty in an elderly population. The system is suitable for everyday use at home, but also for more in-depth observation of various biological parameters, such as the heart rate and temperature.