Virtual Reality最新文献

Aimed at limitations in the description and expression of three-dimensional (3D) physical information in two-dimentsional (2D) medical images, feature extraction and matching method based on the biomedical characteristics of skeletons is employed in this paper to map the 2D images of skeletons into a 3D digital model. Augmented reality technique is used to realize the interactive presentation of skeleton models. Main contents of this paper include: Firstly, a three-step reconstruction method is used to process the bone CT image data to obtain its three-dimensional surface model, and the corresponding 2D–3D bone library is established based on the identification index of the 2D image and the 3D model; then, a fast and accurate feature extraction and matching algorithm is developed to realize the recognition, extraction, and matching of 2D skeletal features, and determine the corresponding 3D skeleton model according to the matching result. Finally, based on the augmented reality technique, an interactive immersive presentation system is designed to achieve visual effects of the virtual human bone model superimposed and rendered in the world scenes, which improves the effectiveness of information expression and transmission, as well as the user's immersion and embodied experience.

This study explores the effect of the experimenter’s gender/sex and its interaction with the participant’s gender/sex as potential contributors to the replicability crisis, particularly in the man-gendered domain of VR. 75 young men and women from Western France were randomly evaluated by either a man or a woman during a 13-min immersion in a first-person shooter game. Self-administered questionnaires were used to measure variables commonly assessed during VR experiments (sense of presence, cybersickness, video game experience, flow). MANOVAs, ANOVAs and post-hoc comparisons were used. Results indicate that men and women differ in their reports of cybersickness and video game experience when rated by men, whereas they report similar measures when rated by women. These findings are interpreted as consequences of the psychosocial stress triggered by the interaction between the two genders/sexes, as well as the gender conformity effect induced, particularly in women, by the presence of a man in a masculine domain. Corroborating this interpretation, the subjective measure of flow, which is not linked to video games and/or computers, does not seem to be affected by this experimental effect. Methodological precautions are highlighted, notably the brief systematic description of the experimenter, and future exploratory and confirmatory studies are outlined.

Graphical abstract

Mixed reality technologies, such as virtual (VR) and augmented (AR) reality, present promising opportunities to advance education and professional training due to their adaptability to diverse contexts. Distortions in the perceived distance in such mediated conditions, however, are well documented and have imposed nontrivial challenges that complicate and limit transferring task performance in a virtual setting to the unmediated reality (UR). One potential source of the distance distortion is the vergence-accommodation conflict—the discrepancy between the depth specified by the eyes’ accommodative state and the angle at which the eyes converge to fixate on a target. The present study involved the use of a manual pointing task in UR, VR, and AR to quantify the magnitude of the potential depth distortion in each modality. Conceptualizing the effect of vergence-accommodation offset as a constant offset to the vergence angle, a model was developed based on the stereoscopic viewing geometry. Different versions of the model were used to fit and predict the behavioral data for all modalities. Results confirmed the validity of the conceptualization of vergence-accommodation as a device-specific vergence offset, which predicted up to 66% of the variance in the data. The fitted parameters indicate that, due to the vergence-accommodation conflict, participants’ vergence angle was driven outwards by approximately 0.2°, which disrupted the stereoscopic viewing geometry and produced distance distortion in VR and AR. The implications of this finding are discussed in the context of developing virtual environments that minimize the effect of depth distortion.

Balance problems are widely reported in Pediatric Brain Tumor Survivors (PBTS) due to tumor localization and the side effects of medical treatment. This study investigates the effects of conventional versus video-based games exercise training (exergaming) on balance in PBTS. The present study was a randomized controlled trial. The study included 23 PBTS who were randomized to a Video-Based balance exergaming Group (VBG) or Conventional balance exercise training Group (CG). In both groups, the interventions were targeted to the balance function and balance exercise training was administered twice a week for 8 weeks. VBG exercised using selected Nintendo Wii Fit Plus® balance games while CG received a specially designed balance training using conventional physiotherapy methods. The primary outcome was the balance tests (Timed Up and Go and Nintendo® Wii™ Center of Gravity: COG), and the secondary outcomes were the functional tests (10-m walking, 2-min walking, 5-step climb/descent/times), and disease effect test (PedsQL Brain Tumor Module). The outcomes were assessed before and after the intervention. At baseline, no significant clinical and outcome assessment differences existed between both groups except for COG (p = 0.0495). After training, overall scores for balance, functional, disease effect tests significantly improved in VBG (p < 0.05) while progress observed in CG was not significant (p > 0.05). Video-based balance exergaming was found effective and more so than conventional balance exercise training in PBTS. Greater effectiveness of exergaming is thought to be due to increased motivation and effort of the children who are more attracted to gaming than conventional exercising. Exergaming could be beneficial both in clinical and home settings with physiotherapist supervision and may reduce the costs of treatment while improving their health-related quality of life.

This study aims to identify effective ways to design virtual rehabilitation to obtain physical improvement (e.g. balance and gait) and support engagement (i.e. motivation) for people with osteoporosis or other musculoskeletal disorders. Osteoporosis is a systemic skeletal disorder and is among the most prevalent diseases globally, affecting 0.5 billion adults. Despite the fact that the number of people with osteoporosis is similar to, or greater than those diagnosed with cardiovascular disease and dementia, osteoporosis does not receive the same recognition. Worldwide, osteoporosis causes 8.9 million fractures annually; it is associated with substantial pain, suffering, disability and increased mortality. The importance of physical therapy as a rehabilitation strategy to avoid osteoporosis fracture cannot be over-emphasised. However, the main rehabilitation challenges relate to engagement and participation. The use of virtual rehabilitation to address such challenges in the delivery of physical improvement is gaining in popularity. As there currently is a paucity of literature applying virtual rehabilitation to patients with osteoporosis, the authors broadened the search parameters to include articles relating to the virtual rehabilitation of other skeletal disorders (e.g. Ankylosing spondylitis, spinal cord injury, motor rehabilitation, etc.). This systematic review initially identified 130 titles, from which 23 articles (involving 539 participants) met all eligibility and selection criteria. Four groups of devices supporting virtual rehabilitation were identified: a head-mounted display, a balance board, a camera and more specific devices. Each device supported physical improvement (i.e. balance, muscle strength and gait) post-training. This review has shown that: (a) each device allowed improvement with different degrees of immersion, (b) the technology choice is dependent on the care need and (c) virtual rehabilitation can be equivalent to and enhance conventional therapy and potentially increase the patient’s engagement with physical therapy.

In recent decades, the senior adults population worldwide has increased, as well as the medical conditions related to aging, such as cognitive decline. Virtual reality (VR) games are a valuable addition to conventional cognitive rehabilitation as they increase engagement to the therapy through customization, socialization, immersion, and feedback. This review, performed according to PRISMA protocol, addresses the following questions: How VR games have been used for cognitive rehabilitation?, What cognitive domains have been addressed by VR games and in which populations have these games been used?, Which features have been considered to improve engagement in VR games for cognitive rehabilitation?, How is the difficulty adjustment of exercises carried out in VR games for cognitive rehabilitation?. We found 25 scientific works related to these questions, 92% of them treating one cognitive domain at a time, despite the fact that the related literature recognizes the value of training multiple domains simultaneously. Our review indicates that, despite the existence of serious VR games for working memory training, such as those described in Flak et al. (Front Psychol 10:807, 2019. https://doi.org/10.3389/fpsyg.2019.00807), to our knowledge, there are no applications that simultaneously address multiple cognitive domains and incorporate dynamic difficulty adjustment, which are important to ensure ecological validity of therapy and therapy adherence, respectively. In addition, we found that games themselves could be used to monitor the user’s progression. It is also important to determine the impact of multiplayer interactions in the game, test difficulty adjustment approaches that use physiological variables, and define difficulty-skill relationships aligned with the user’s preferences. This paper concludes that the main barriers to implement dynamic difficulty adjustment in VR games for cognitive rehabilitation are: (i) the absence of metrics to estimate when the game offers to the players a challenge adapted their skills, and (ii) the lack of a conceptual framework that integrates relevant theories such as state of flow, cognitive load, cognitive rehabilitation, and feedback systems.

Abstract

The execution of object-directed motor actions is known to be influenced by the intention to interact with others. In this study, we tested whether the effects of social intention on the kinematics of object-directed actions depended on whether the task was performed in the presence of a human or a virtual confederate. In two experiments, participants had to grasp a glass and place it to a new position, with either a personal intention (to fill the glass themselves using a bottle) or a social one (to have the glass filled by the human confederate or the virtual agent using the bottle). Experiment 1 showed that the kinematics of the object-directed actions was modulated by the social intention but only when interacting with a human confederate. Experiment 2 showed that the effects of social intention on object-directed actions performance can be improved using feedback-based learning. Specifically, participants proved able to progressively adapt their motor performances as if they were expressing social intention to a virtual confederate as well. These findings emphasize the importance of the modulatory role of social intention on non-verbal motor behaviour, and enrich the understanding of the interaction with virtual agents.

Abstract

Experts have called for virtual reality (VR) training and learning applications that can facilitate the changes needed in training programmes for years to come. To help expedite the adoption process, this study used a mixed-methods approach to identify the key factors that promote intentions to use VR technology in medical training. The qualitative research was based on interviews with five doctors and medical students, which focused on identifying the most significant determinants. Next, a survey was conducted to collect data from 154 medical interns and students in Spanish universities and hospitals, whose responses were processed using partial least squares-structural equation analysis. The limited sample size means this study is exploratory. The results indicate that perceived entertainment significantly strengthens behavioural intention to use VR technology in medical courses. The findings also underline the potential uses of VR learning tools in healthcare contexts and the need to incorporate this technology into medical training.

This study explores technology acceptance, perception and user assessment of an immersive virtual reality environment with computational fluid dynamics simulations in engineering education. 57 participants from three different institutions tested the virtual reality application. Partial least squares structural equation modeling and interferential statistics were performed to predict and assess interrelations among constructs. Results show that the learning value, content value, intrinsic motivation and personal innovativeness are underlying factors behind students’ intention to use virtual reality. Pair-wise analysis indicates that users’ perceptions matter and positively affect their attitudes. In addition, the virtual reality application helps students perform significantly better in the post-knowledge test. Findings also highlight that prior experience and interest can affect students’ attitudes and behavioral intentions to accept the virtual reality application in education. Our study can guide lecturers and developers to achieve on-target immersive virtual reality learning environments in higher education.

Identifying users’ experience when using products is one of the major challenges for design. Analyzing users’ psychophysiological reactions to an experience using biofeedback can produce more reliable results than using subjective evaluations, such as structured interviews and questionnaires. Two case studies were conducted to identify emotions users actually felt and to check whether there is some correspondence with what they reported after using two computational systems. The first system investigated users’ emotions during training on a vehicle driving simulator, and the second analyzed the emotions experienced during a car racing game, both in a virtual reality environment. User’s opinions about their emotional state were obtained using self-report techniques (using the Geneva Emotions Wheel—GEW and Positive and Negative Affective Schedule—PANAS questionnaires) and applying EEG (brain activity with Frontal Alpha Asymmetry Index—FAAI) and infrared thermography (facial thermograms). The training experiment presented the greater concordance between the psychophysiological and the self-report responses. Results evidenced the importance of undertaking multimodal studies in design research to determine users’ emotional experiences in a virtual reality context.