virtual reality, distributed, massed

BACKGROUND: Patients with single ventricle heart defects receive 3 stages of operations culminating in the Fontan procedure. During the Fontan procedure, a vascular graft is sutured between the inferior vena cava and pulmonary artery to divert deoxygenated blood flow to the lungs via passive flow. Customizing the graft configuration can maximize the long-term benefits. However, planning patient-specific procedures has several challenges, including the ability for physicians to customize grafts and evaluate their hemodynamic performance...

Postural instability marks one of the most disabling features of Parkinson's disease (PD), but only reveals itself after affected brain areas have already been significantly damaged. Thus, there is a need to detect deviations in balance and postural control before visible symptoms occur. In this study, we visually perturbed balance in the anterior-posterior direction using sinusoidal oscillations of a moving room in virtual reality at different frequencies. We tested three groups: individuals with PD under dopaminergic medication, an age-matched control group, and a group of young healthy adults...

PURPOSE: Reliable assessment of surgical skills is vital for competency-based medical training. Several factors influence not only the reliability of judgments but also the number of observations needed for making judgments of competency that are both consistent and reproducible. The aim of this study was to explore the role of various conditions-through the analysis of data from large-scale, simulation-based assessments of surgical technical skills-by examining the effects of those conditions on reliability using generalizability theory...

In this paper, we present a fully-customized AR display design that considers the user's prescription, interpupillary distance, and taste of fashion. A free-form image combiner embedded inside the prescription lens provides augmented images onto the vision-corrected real world. The optics was optimized for each prescription level, which can reduce the mass production cost while satisfying the user's taste. The foveated optimization method was applied which distributes the pixels in accordance with human visual acuity...

We propose and evaluate novel pseudo-haptic techniques to display mass and mass distribution for proxy-based object manipulation in virtual reality. These techniques are specifically designed to generate haptic effects during the object's rotation. They rely on manipulating the mapping between visual cues of motion and kinesthetic cues of force to generate a sense of heaviness, which alters the perception of the object's mass-related properties without changing the physical proxy. First we present a technique to display an object's mass by scaling its rotational motion relative to its mass...

Virtual reality (VR) simulation-based training is increasingly used in surgical technical skills training including in temporal bone surgery. The potential of VR simulation in enabling high-quality surgical training is great and VR simulation allows high-stakes and complex procedures such as mastoidectomy to be trained repeatedly, independent of patients and surgical tutors, outside traditional learning environments such as the OR or the temporal bone lab, and with fewer of the constraints of traditional training...

IMPORTANCE: The ultimate goal of surgical training is consolidated skills with a consistently high performance. However, surgical skills are heterogeneously retained and depend on a variety of factors, including the task, cognitive demands, and organization of practice. Virtual reality (VR) simulation is increasingly being used in surgical skills training, including temporal bone surgery, but there is a gap in knowledge on the retention of mastoidectomy skills after VR simulation training...

IMPORTANCE: Repeated and deliberate practice is crucial in surgical skills training, and virtual reality (VR) simulation can provide self-directed training of basic surgical skills to meet the individual needs of the trainee. Assessment of the learning curves of surgical procedures is pivotal in understanding skills acquisition and best-practice implementation and organization of training. OBJECTIVE: To explore the learning curves of VR simulation training of mastoidectomy and the effects of different practice sequences with the aim of proposing the optimal organization of training...

OBJECTIVES/HYPOTHESIS: Cognitive load theory states that working memory is limited. This has implications for learning and suggests that reducing cognitive load (CL) could promote learning and skills acquisition. This study aims to explore the effect of repeated practice and simulator-integrated tutoring on CL in virtual reality (VR) mastoidectomy simulation. STUDY DESIGN: Prospective trial. METHODS: Forty novice medical students performed 12 repeated virtual mastoidectomy procedures in the Visible Ear Simulator: 21 completed distributed practice with practice blocks spaced in time and 19 participants completed massed practice (all practices performed in 1 day)...

Virtual and augmented reality surgery calls for reliable and efficient tracking of the surgical instruments in the virtual or real operating theatre. The most diffused approach uses three or more not aligned markers, attached to each instrument and surveyed by a set of cameras. However, the structure required to carry the markers does modify the instrument's mass distribution and can interfere with surgeon movements. To overcome these problems, we propose here a new methodology, based on structured markers, to compute the six degrees of freedom of a surgical instrument...

BACKGROUND: The unique psychomotor skills required in laparoscopy result in reduced patient safety during the early part of the learning curve. Evidence suggests that these may be safely acquired in the virtual reality (VR) environment. Several VR simulators are available, each preloaded with several psychomotor skills tasks that provide users with computer-generated performance metrics. This review aimed to evaluate the usefulness of specific psychomotor skills tasks and metrics, and how trainers might build an effective training curriculum...

BACKGROUND: Laparoscopic skills are difficult to learn. We, therefore, assessed the factors involved in skill acquisition, maintenance, and loss in 2 prospective, randomized studies. METHODS: In study 1, 24 laparoscopic novices were randomly assigned to a control condition who performed the laparoscopic assessment task; Massed condition who trained on virtual reality (VR) simulation during 1 day or Interval condition who had the same amount of VR training distributed over 3 consecutive days...

The development of the Internet and its gradual mass distribution in the last 20 years have marked the beginning of a global revolution in the way of communicating and thinking. In this context, emerged disorders related to a pathological use of the network, up to forms of real addiction (Internet Addiction Disorder), similar to the use of psychotropic substances. The abuse of the Internet can seriously aggravate pre-existing psychopathological traits, which are the basis of addiction, resulting in a continuous process of disconnection from reality...

The aim of this work is to develop a realistic virtual model of the human brain that could be used in a neurosurgical simulation for both educational and preoperative planning purposes. The goal of such a system would be to enhance the practice of surgery students, avoiding the use of animals, cadavers and plastic phantoms. A surgeon, before carrying out the real procedure, will, with this system, be able to rehearse by using a surgical simulator based on detailed virtual reality models of the human brain, reconstructed with real patient's medical images...

OBJECTIVE: To create and evaluate a pilot bioterrorism defense training environment using virtual reality technology. METHODS: The present pilot project used Second Life, an internet-based virtual world system, to construct a virtual reality environment to mimic an actual setting that might be used as a Strategic National Stockpile (SNS) distribution site for northern California in the event of a bioterrorist attack. Scripted characters were integrated into the system as mock patients to analyze various clinic workflow scenarios...

BACKGROUND: Psychomotor skills for endoscopic surgery can be trained with virtual reality simulators. Distributed training is more effective than massed training, but it is unclear whether distributed training over several days is more effective than distributed training within 1 day. This study aimed to determine which of these two options is the most effective for training endoscopic psychomotor skills. METHODS: Students with no endoscopic experience were randomly assigned either to distributed training on 3 consecutive days (group A, n = 10) or distributed training within 1 day (group B, n = 10)...

Modelling of soft tissue deformation is of great importance to virtual reality based surgery simulation. This paper presents a new methodology for simulation of soft tissue deformation by drawing an analogy between autowaves and soft tissue deformation. The potential energy stored in a soft tissue as a result of a deformation caused by an external force is propagated among mass points of the soft tissue by non-linear autowaves. The novelty of the methodology is that (i) autowave techniques are established to describe the potential energy distribution of a deformation for extrapolating internal forces, and (ii) non-linear materials are modelled with non-linear autowaves other than geometric non-linearity...