Advanced visualization for finite elements analysis in virtual reality environments

A new visualization method for an illustrative visualization of physical parameters in immersive workspaces is presented. Through the newly developed visualization pipeline, FEM results such as stress, temperature and resulting deformation, as well as the underlying constraints can be visualized in virtual and augmented reality applications. Special features are the use of 3D glyphs for mapping stress direction and gradient as well as data preparation and the resulting data format, which was especially developed for use with VR systems. This article demonstrates the current state of VR developments, which were done at the Virtual Reality Center Production Engineering of the Institute for Machine Tools and Production Processes, for improving the analysis of complex FE datasets, and gives an outlook to future research activities.     

Significant applications of virtual reality for COVID-19 pandemic

Background and aimsDuring COVID-19 pandemic, researchers are using innovative technologies for fast-tracking the development to end this menace. Virtual Reality (VR) also offers an imperative role for fighting this pandemic, through audiovisual-based virtual communication.MethodsA brief study on Virtual Reality and its applications for the COVID-19 pandemic is carried out by employing keywords as Virtual reality or VR and COVID-19 from the databases of SCOPUS, Google Scholar, PubMed, Web of science Academia and ResearchGate.ResultsVR is beneficial for remote sites for exploring telemedicine, planning, treatment, and controlling of the infections by providing proper awareness to the people regarding this disease.ConclusionsVR technology develops a platform to reduce the face to face interaction of doctors with the infected COVID-19 patients. Through live video streaming, it helps to improve surveillance systems on the ongoing situation.     

Touch-sensitive augmented reality system for development of handheld information appliances

Handheld information devices such as digital cameras and smart-phones are products that unify hardware and software. The body of such products is compact, but it has various functions. Usability is one of the most important factors affecting their commercial competitiveness. However, it is difficult to estimate usability precisely in the design process. Because of usability is strongly affected by the shape of the body, the types and arrangement of the switches etc. In order to accurately evaluate the usability of these products, users must operate them directly. However it is difficult to manufacture prototypes that are operable. Therefore, we have adopted an augmented reality technique to solve the problem. This paper introduces, a touch-sensitive augmented reality system, and describes the construction of a touch sensor made of pressure sensitive conductive rubber, a fingertip tracing method using an LED marker, and an augmented reality system. Finally, we have conducted basic system evaluations.     

360° video recording inside a GI endoscopy room: Technical feasibility and its potential use for the acquisition of gastrointestinal endoscopy skills. Pilot experience

New advances in video processing, 3-dimensional designs, and augmented/virtual reality are exciting and evolving fields. These new tools can facilitate the learning phase of basic or advanced endoscopic procedures. Herein, we explain our initial experience, creating an immersive virtual reality (IVR) by using 360-degree recording videos from an interventional endoscopy room.Some common terms used around this technology, such as Augmented reality (AR), Virtual Reality (VR), Three hundred sixty videos, and Mixed Reality (MR), are discussed below.Three examples of VR 360 endoscopic room videos are included in this article.     

Virtual reality approaches for immersive design

The current application of virtual reality (VR) systems in the design process is limited mostly to design review. The reason for this limitation is the different data formats used for CAD and VR visualization. To use the benefits of VR during the design process, solutions for immersive design, the model manipulation inside the VE based on CAD data, are required. There are different approaches allowing VR systems to work as an active development platform. Three examples introduce the realization of the integration of CAD and VR software at different levels by the online coupling of complete applications or by integration of CAD core functionalities in VR systems.     

Low spatial coherence electrically pumped semiconductor laser for speckle-free full-field imaging

The spatial coherence of laser sources has limited their application to parallel imaging and projection due to coherent artifacts, such as speckle. In contrast, traditional incoherent light sources, such as thermal sources or light emitting diodes (LEDs), provide relatively low power per independent spatial mode. Here, we present a chip-scale, electrically pumped semiconductor laser based on a novel design, demonstrating high power per mode with much lower spatial coherence than conventional laser sources. The laser resonator was fabricated with a chaotic, D-shaped cavity optimized to achieve highly multimode lasing. Lasing occurs simultaneously and independently in ∼1,000 modes, and hence the total emission exhibits very low spatial coherence. Speckle-free full-field imaging is demonstrated using the chaotic cavity laser as the illumination source. The power per mode of the sample illumination is several orders of magnitude higher than that of a LED or thermal light source. Such a compact, low-cost source, which combines the low spatial coherence of a LED with the high spectral radiance of a laser, could enable a wide range of high-speed, full-field imaging and projection applications.Spatial coherence is a defining characteristic of laser emission. High spatial coherence allows focusing electromagnetic energy to a small spot or collimation of an optical beam over a long distance. However, spatial coherence can also introduce coherent artifacts such as speckle, because any uncontrolled scattering in the imaging system can cause multipath interference. These artifacts have limited the use of lasers in full-field imaging applications ranging from traditional wide-field microscopes to laser projectors, holography, and photolithography systems. Instead, traditional low spatial coherence sources such as thermal light sources and light-emitting diodes (LEDs) are still used for illumination in most full-field imaging applications, despite having lower power per mode, poor collection efficiency, and less spectral control than lasers. These limitations are particularly pronounced in applications requiring high-speed imaging or imaging in absorbing or scattering media, prompting the use of raster-scanning–based laser imaging systems. For parallel imaging and projection applications, the ideal illumination source would combine the high power per mode of a laser with the low spatial coherence of an LED. The common approach to achieve this combination is by reducing the effective spatial coherence of a traditional laser using, e.g., a spinning diffuser (1), a colloidal solution (2), or a microelectromechanical mirror (3). However, these techniques require averaging over many speckle patterns in time, mitigating the advantage of using bright sources such as lasers or superluminescent diodes for high-speed imaging applications. Another approach to suppress speckle is by taking advantage of the low temporal coherence of broadband sources like superluminescent diodes (SLDs) and supercontinuum sources (4). However, these sources maintain high spatial coherence and still produce speckle with notable contrast in most imaging contexts (5). Moreover, this approach cannot be adopted for applications that rely on narrowband illumination such as deep UV photolithography with excimer lasers.An alternative and more effective approach is to design a laser that generates light in an intermediate number of spatial modes, producing sufficiently low spatial coherence to suppress speckle, while maintaining higher power per mode than an LED or a thermal light source. To this end, we recently demonstrated that a random laser (5, 6) and a degenerate laser (7) can be engineered to efficiently control the spatial coherence of emission. However, the required optical pumping, together with the large size and cost of these systems, may limit their use outside of a research setting. Similar functionality has also been realized by combining many independent lasers to synthesize a low spatial coherence laser source. For example, a recently developed vertical cavity surface-emitting laser (VCSEL) array combines ∼1,000 mutually incoherent lasers on a single chip (8). However, this approach requires a relatively large chip because the lasers must be sufficiently separated to remain uncoupled. In addition, the individual VCSELs typically lase in a single longitudinal mode due to the short cavity length, limiting the ability to generate broadband emission required for imaging modalities such as optical coherence tomography (OCT) and laser ranging.In this work, we demonstrate a chip-scale electrically pumped semiconductor laser that produces intense emission with low spatial coherence. Specifically, we designed a chaotic microcavity to support highly multimode lasing and experimentally realized lasing in ∼1,000 mutually incoherent modes in a single cavity. The lasing emission was used as an illumination source for speckle-free full-field imaging. The chaotic cavity laser was compared with a standard Fabry–Perot (FP) cavity laser that produced emission with high spatial coherence. The chaotic microcavity laser was fabricated by photolithography and wet etching and hence was relatively simple and compatible with mass production. The lasing performance was robust against cavity shape deformation and boundary roughness. Such a compact, low-cost laser with low spatial coherence and high radiance could enable a wide range of high-speed, full-field imaging and projection applications.     

Augmented reality (AR) and virtual reality (VR) applied in dentistry

The OSCE is a reliable evaluation method to estimate the preclinical examination of dental students. The most ideal assessment for OSCE is used the augmented reality simulator to evaluate. This literature review investigated a recently developed in virtual reality (VR) and augmented reality (AR) starting of the dental history to the progress of the dental skill. As result of the lacking of technology, it needs to depend on other device increasing the success rate and decreasing the risk of the surgery. The development of tracking unit changed the surgical and educational way. Clinical surgery is based on mature education. VR and AR simultaneously affected the skill of the training lesson and navigation system. Widely, the VR and AR not only applied in the dental training lesson and surgery, but also improved all field in our life.     

Improved virtual reality perception with calibrated stereo and variable focus for industrial use

3D image rendering for virtual reality HMDs is typically generated based on a set of parameters taken from the manufacturer-supplied specifications and an idealised perspective model. But actual displays may vary in build features that alter spatial perception. Moreover, the eye focusing effort is often ignored. The resulting visual discomfort and incorrect geometry perception has discouraged use of immersive virtual reality in industrial applications. This work addresses these issues and describes a system with per-device calibration and control of stereo perspective projections and focus. The ideas presented may improve the usefulness of VR in industrial training and visualization.     

Augmented reality 3D navigation system for percutaneous CT-guided pulmonary ground-glass opacity biopsies: a comparison with the standard CT-guided technique

BackgroundAugmented reality navigation system for percutaneous computed tomography (CT)-guided pulmonary biopsies has recently been introduced. There are no studies in literature about its use for ground glass lesions biopsies. The aim of this study is to evaluate the effectiveness of an augmented reality infrared navigation system performance on CT-guided percutaneous lung ground glass opacity (GGO) biopsy compared to a standard CT-guided technique.MethodsA total of 80 patients with lung GGO who underwent to a percutaneous CT-guided lung biopsy with an augmented reality infrared navigation system were retrospectively enrolled in the study. Comparison was performed with a group of 80 patients who underwent to lung biopsy with the standard CT-guided technique. Evaluation of maximum lesion diameter (MLD), distance between lesion and pleural surface (DPS), distance travelled by the needle (DTP), procedural time, validity of histological sample, procedural complications and the radiation dose to the patient’s chest were recorded for each patient of both groups. In addition, each group was divided into two subgroups based on lesion size, according to a cut-off of 1.5 cm (<1.5 cm; ≥1.5 cm).ResultsAugmented reality navigation system showed a significant reduction in procedural time, radiation dose administrated to patients and complications rate compared to a standard CT-guided technique. Technical success was achieved in the 100% of cases in both groups, but the diagnostical success was higher in the group where patients underwent to lung biopsies with the use of navigation system. We also found that using an augmented reality navigation system increases the diagnostical success rate for lesion <1.5 cm. MLD, DPS and DTP did not differ significantly between the two groups of patients.ConclusionsThe use of an augmented reality navigation system for percutaneous CT-guided pulmonary GGO biopsies has demonstrated a lower incidence of post-procedural complications, a significantly reduction of the radiation dose administered to patients and a higher diagnostical success rate.     

Natural interface for interactive virtual assembly in augmented reality using Leap Motion Controller

In this paper, an augmented reality methodology based on the use of a low-invasiveness hand tracking device is presented. The developed methodology, allows the user to be visually immersed into an augmented scene by means of a head-mounted display. He can interact with the virtual objects without any wearable sensor using the Leap Motion Controller that is able to acquire the pose of each finger of both hands by optical triangulation without markers. In this way, the interaction between the user and the scene can be considered “natural”. The interaction between hands and objects and the assembling among objects is achieved by the modification of the Object Active Feature–Grasping Active Feature methodology, based on the use of algebraic kinematic constraint equations. The approach has been adapted to take into account the specific information coming from the tracking device. An example of implementation is reported and an experimental usability study discussed.     

Interactive virtual assembling in augmented reality

In this paper, a computer-aided methodology based on augmented reality to manipulate and interactively assemble virtual objects is presented. The developed system, based on both hardware and software implementation, allows the user to be immersed in an augmented scene (real world and virtual objects) by means of an head-mounted display and interact with the virtual components using a glove with sensors. The author presents the implementation of the system facing the problems concerning the interpretation of user’s intent to grasp and move the objects and the computer-aided assembly based on a novel approach concerning active features dynamic recognition. An example of implementation is herein reported and discussed.     

GARDE: a gesture-based augmented reality design evaluation system

Design evaluation and modification plays a critical role in the design process to develop products that meet the user requirements. Physical prototypes are commonly used to evaluate a design and justify design changes. However, physical prototypes are costly and cannot be modified. Virtual prototypes have been used but it is difficult to simulate virtual prototypes accurately and contextualize them. In this paper, a gesture-based augmented reality design evaluation system (GARDE) is presented. Using AR, GARDE is able to enjoy the benefits of both physical and virtual prototyping in design evaluation. In addition, the use of hand gestures as the main interaction input allows for interactive and intuitive design evaluation. Through the use of an off-the-shelf CAD software API, modifications of the 3D models in an AR environment can be achieved. As design evaluation is conducted in a real environment, in-situ design can also be performed using GARDE. Two case studies have been carried to demonstrate the GARDE system and are described in this paper.     

IMPROVE: An innovative application for collaborative mobile mixed reality design review

In this paper we introduce an innovative application aiming at combining large, tablet-based and headmounted displays for collaborative mobile mixed reality design reviews. Our research and development is motivated by two use scenarios: automotive and architectural design review involving real users from Page/Park architects and Elasis FIAT. Our activities are supported by the EU IST project IMPROVE. It covers activities in the areas of: HMD development using unique OLED technology, markerless tracking, augmented reality rendering, image calibration for large tiled displays, collaborative tablet-based and projection wall oriented interaction and stereoscopic video streaming for mobile users. The paper gives an overview of the hardware and software developments within IMPROVE and concludes with results from first user test.     

Mobile devices within manufacturing environments: a BMW applicability study

With the growing need of mobile devices within manufacturing industries, new domains for their use in automotive OEMs have emerged. Advent technology has enabled the development of devices such as ultra-mobile personal computers that provide the function of a computer in a compact, mobile configuration and augmented reality (wearable mobile devices) in a production environment where hands free operation is essential. The use of mobile devices allows for more effective communication and data sharing/recording. This paper details BMW’s preliminary investigation and applicability study of implementing mobile devices within their manufacturing environment to view potential benefits that could be achieved. Manufacturing industries are characterized by many diverse and critical processes, and an effective communication mechanism must be available between such critical processes. It is recognized that the potential for mobile devices in manufacturing process, while realized through current use of mobile phones and PDAs, has not been fully exploited with newer technology. With use of mobile broadband communication, mobile devices can be used for audio and visual communication and provide the ability to transfer large data volumes without location constraints. BMW explores the use of mobile devices use within two manufacturing processes: assembly training and pruefcubing. Through an internal study performed, it is realized that the use of mobile devices demonstrates improvements within the manufacturing process in terms of time efficiency, quality, and communication capabilities. However, the risks and limitations of implementing such systems have prevented their entrance into assembly training and pruefcubing. The deterrent limitations are discussed and future work is proposed for reevaluation.     

Brain correlates of subjective reality of physically and psychologically induced pain

Meaningful behavior requires successful differentiation of events surfacing from one's mind from those arising from the external world. Such judgements may be especially demanding during pain because of the strong contribution from psychological factors to this experience. It is unknown how the subjective reality of pain (SRP) is constructed in the human brain, and neuronal mechanisms of the subjective reality are poorly understood in general. To address these questions, 14 suggestion-prone healthy subjects rated reality of pain that was induced either by laser pulses to the skin or by hypnotic suggestion during functional MRI. Both pain states were associated with activation of the brain's pain circuitry. During laser stimulation, the sensory parts of this circuitry were activated more strongly, and their activation strengths correlated positively with the SRP. During suggestion-induced pain, the reality estimates were lower and correlated positively with activation strengths in the rostral and perigenual anterior cingulate cortex and in the pericingulate regions of the medial prefrontal cortex; a similar trend was evident during laser-induced pain. These findings support the view that information about sensory-discriminative characteristics of pain contributes to the SRP. Differences in such information between physically and psychologically induced pain, however, could be quantitative rather than qualitative and therefore insufficient for judging the reality of pain without knowledge about the source of this information. The medial prefrontal cortex is a likely area to contribute to such source monitoring.     

An Automatic on Top Analysis of Single Scan Tracks to Evaluate the Laser Powder Bed Fusion Building Parameters

The production of dense samples produced by laser powder bed fusion (LPBF) is mainly determined by the choice of the best combination of construction parameters. Parameter optimization is the first step in the definition of an LPBF process for new alloys or systems. With this goal, much research uses the single scan track (SST) approach for a preliminary parameter screening. This study investigates the definition of a computer-aided method by using an automatic on top analysis for the characterization of SSTs, with the aim of finding ranges of laser power and scan speed values for massive production. An innovative algorithm was implemented to discard non-continuous scans and to measure the SSTs quality using three regularity indexes. Only open source software were used to fine tune this approach. The obtained results on Al4Cu and AlSi10Mg realized with two different commercial systems suggest that it is possible to use this method to easily narrow the process parameter window that allows the production of dense samples.     

Role of virtual reality simulation in endoscopy training

Recent advancements in virtual reality graphics and models have allowed virtual reality simulators to be incorporated into a variety of endoscopic training programmes. Use of virtual reality simulators in training programmes is thought to improve skill acquisition amongst trainees which is reflected in improved patient comfort and safety. Several studies have already been carried out to ascertain the impact that usage of virtual reality simulators may have upon trainee learning curves and how this may translate to patient comfort. This article reviews the available literature in this area of medical education which is particularly relevant to all parties involved in endoscopy training and curriculum development. Assessment of the available evidence for an optimal exposure time with virtual reality simula-tors and the long-term benefits of their use are also discussed.     

Virtual reality aided design of parts and assemblies

Current virtual reality (VR) systems provide an enormous potential for enhancing the visualization of 3D-design drafts. Based on new navigation techniques the designer is able to interact, model in a more intuitive and efficient way. In our contribution we present a novel interaction metaphor that facilitates the synthesis of efficient virtual reality interaction and visualization techniques with modern feature based CAD systems. We present “NAVIMODE”, an alternative approach for navigation, manipulation and selection, to combine the advantages of VR and CAD systems. The design engineer has the chance to design in his/her habitual environment using the advantage of virtual reality concurrently.     

Virtual concepts and experiments to improve quality of train interiors

The paper aims at providing a methodological contribution to the concept design of train interior in order to improve the quality perceived by users in compliance with railway standards. Indeed, the combined use of advanced CAD tools, experimental statistical methods and Virtual Reality tools allows developing, selecting and experimentally evaluating new concepts. The design cycle starts both from designers’ proposal and the identification of user’s needs; then, it makes use of datum-based CAD models in order to generate virtual concepts that satisfy railway standards; the cycle proceeds with the immersive evaluation of virtual prototypes, performed by potential and expert users in Virtual Reality. The identification of the optimal concept closes the design process. This procedure can be iterated in order to improve the quality of train interiors, evaluated thanks to the user’s involvement in the design cycle. In this work a case study on seat design of a regional train is presented, developed at the Virtual Reality laboratory, named VRTest, of the Regional Centre for the qualification of transportation systems set up by Campania Regional Authority.     

Turning virtual reality into reality: a checklist to ensure virtual reality studies of eating behavior and physical activity parallel the real world

Virtual reality (VR) provides a potentially powerful tool for researchers seeking to investigate eating and physical activity. Some unique conditions are necessary to ensure that the psychological processes that influence real eating behavior also influence behavior in VR environments. Accounting for these conditions is critical if VR-assisted research is to accurately reflect real-world situations. The current work discusses key considerations VR researchers must take into account to ensure similar psychological functioning in virtual and actual reality and does so by focusing on the process of spontaneous mental simulation. Spontaneous mental simulation is prevalent under real-world conditions but may be absent under VR conditions, potentially leading to differences in judgment and behavior between virtual and actual reality. For simulation to occur, the virtual environment must be perceived as being available for action. A useful chart is supplied as a reference to help researchers to investigate eating and physical activity more effectively.