Freehand-Steering Locomotion Techniques for Immersive Virtual Environments: A Comparative Evaluation

Virtual reality has achieved significant popularity in recent years, and allowing users to move freely within an immersive virtual world has become an important factor critical to realize. The user’s interactions are generally designed to increase the perceived realism, but the locomotion techniques and how these affect the user’s task performance still represent an open issue, much discussed in the literature. In this article, we evaluate the efficiency and effectiveness of, and user preferences relating to, freehand locomotion techniques designed for an immersive virtual environment performed through hand gestures tracked by a sensor placed in the egocentric position and experienced through a head-mounted display. Three freehand locomotion techniques have been implemented and compared with each other, and with a baseline technique based on a controller, through qualitative and quantitative measures. An extensive user study conducted with 60 subjects shows that the proposed methods have a performance comparable to the use of the controller, further revealing the users’ preference for decoupling the locomotion in sub-tasks, even if this means renouncing precision and adapting the interaction to the possibilities of the tracker sensor

Real-time Adaptive GPU multi-agent path planning

This chapter presents a GPU path planning algorithm that is derived from the sequential A* algorithm to allow massively parallel, real-time execution. The new algorithm employs a limited lookahead strategy similar to the wave fronts of a breath-first search algorithm. Using a heuristic to estimate the most profitable direction for moving along a particular direction at each step, the algorithm strikes a balance between work set size and optimality. The implementation of the algorithm further employs a windowed strategy to reduce the amount of information that needs to be maintained for fast access. We show that the resulting algorithm indeed achieves high efficiency while yielding good quality movement path

la pressione venosa centrale nella fase acuta dell'infarto del miocardio. Considerazioni su 363 casi.

The behavior of central venous pressure (CVP) has been examined in 363 cases of acute myocardial infarction. It was found that in uncomplicated hemodynamic states of the patients the average CVP was less than 6 cm H2O. In patients with cardiac failure the CVP ranged from 6 to 15 cm H2O; in patients with cardiogenic shock it exceeded 15 cm H2O. Few exceptions have been observed. Some patients without cardiac failure had high CVP while some others with cardiogenic shock provided low CVP values. In patients with myocardial infarction the CVP may be considered a good diagnostic and prognostic sign for hemodynamic complications

Towards a virtual reality cognitive training system for mild cognitive impairment and Alzheimer's disease patients

The rapid growth of the aged population has stimulated research directed at designing interventions to support the associated social, economic and health challenges in an elderly population. Environmental interventions, like cognitive rehabilitation, stimulation and training can significantly improve cognitive functioning, so mitigating the cognitive decline. In this area, the adoption of state-of-the-art virtual reality technologies can provide a cost-effective, flexible and comprehensive solution for realizing complex cognitive training environments. With the aim of preserving mnestic and logical-praxic functions of patients with MCI or Alzheimer's disease at the early stages, in this paper we describe our ongoing work in designing a novel, fullyequipped virtual reality cognitive training system. The system is characterized by a high degree of realism and interactivity, to provide the patient with an adequate sense of presence within the virtual environment. Moreover, it is able to monitor the patient's biomedical signals and collect quantitative data on the training sessions, so allowing the therapist to analyze and tailor the training strategies to the patient

Virtual Reality Rehabilitation Systems for Cancer Survivors: A Narrative Review of the Literature

: Rehabilitation plays a crucial role in cancer care, as the functioning of cancer survivors is frequently compromised by impairments that can result from the disease itself but also from the long-term sequelae of the treatment. Nevertheless, the current literature shows that only a minority of patients receive physical and/or cognitive rehabilitation. This lack of rehabilitative care is a consequence of many factors, one of which includes the transportation issues linked to disability that limit the patient's access to rehabilitation facilities. The recent COVID-19 pandemic has further shown the benefits of improving telemedicine and home-based rehabilitative interventions to facilitate the delivery of rehabilitation programs when attendance at healthcare facilities is an obstacle. In recent years, researchers have been investigating the benefits of the application of virtual reality to rehabilitation. Virtual reality is shown to improve adherence and training intensity through gamification, allow the replication of real-life scenarios, and stimulate patients in a multimodal manner. In our present work, we offer an overview of the present literature on virtual reality-implemented cancer rehabilitation. The existence of wide margins for technological development allows us to expect further improvements, but more randomized controlled trials are needed to confirm the hypothesis that VRR may improve adherence rates and facilitate telerehabilitation

Facial Electromyography-based Adaptive Virtual Reality Gaming for Cognitive Training.

Cognitive training has shown promising results for delivering improvements in human cognition related to attention, problem solving, reading comprehension and information retrieval. However, two frequently cited problems in cognitive training literature are a lack of user engagement with the training programme, and a failure of developed skills to generalise to daily life. This paper introduces a new cognitive training (CT) paradigm designed to address these two limitations by combining the benefits of gamification, virtual reality (VR), and affective adaptation in the development of an engaging, ecologically valid, CT task. Additionally, it incorporates facial electromyography (EMG) as a means of determining user affect while engaged in the CT task. This information is then utilised to dynamically adjust the game’s difficulty in real-time as users play, with the aim of leading them into a state of flow. Affect recognition rates of 64.1% and 76.2%, for valence and arousal respectively, were achieved by classifying a DWT-Haar approximation of the input signal using kNN. The affect-aware VR cognitive training intervention was then evaluated with a control group of older adults. The results obtained substantiate the notion that adaptation techniques can lead to greater feelings of competence and a more appropriate challenge of the user’s skills

Serious Games in the new era of digital-health interventions: A narrative review of their therapeutic applications to manage neurobehavior in neurodevelopmental disorders

Children and adolescents with neurodevelopmental disorders generally show adaptive, cognitive and motor skills impairments associated with behavioral problems, i.e., alterations in attention, anxiety and stress regulation, emotional and social relationships, which strongly limit their quality of life. This narrative review aims at providing a critical overview of the current knowledge in the field of serious games (SGs), known as digital instructional interactive videogames, applied to neurodevelopmental disorders. Indeed, a growing number of studies is drawing attention to SGs as innovative and promising interventions in managing neurobehavioral and cognitive disturbs in children with neurodevelopmental disorders. Accordingly, we provide a literature overview of the current evidence regarding the actions and the effects of SGs. In addition, we describe neurobehavioral alterations occurring in some specific neurodevelopmental disorders for which a possible therapeutic use of SGs has been suggested. Finally, we discuss findings obtained in clinical trials using SGs as digital therapeutics in neurodevelopment disorders and suggest new directions and hypotheses for future studies to bridge the gaps between clinical research and clinical practice