Efficient evaluation of misalignment between real and virtual objects for HMD-Based AR assembly assistance system

Extended-Reality Technologies: An Overview of Emerging Applications in Medical Education and Clinical Care.

Recupera algunos de los elementos menos estudiados y reconocidos en el ensayo latinoamericano: su profunda vocación de reflexión, diálogo y mediación intelectual; su plasticidad y apertura a la búsqueda del sentido; su vínculo con la sociabilidad, la conversación y la generación de un espacio simbólico de encuentro; su capa cidad de establecer una nueva retroalimentación entre lectura y escritura.

Inherent to the field of computer-aided surgery (CAS) is the necessity to handle sophisticated equipment in the operating room; an undesired side-effect of this development is the fact that the surgeon’s attention is drawn from the operating field since surgical progress is partially monitored on the computer’s screen. The overlay of computer-generated graphics over a real-world scene, also referred to as augmented reality (AR), provides a possibility to solve this problem. The considerable technical problems associated with this approach such as viewing of the scenery within a common focal range on the head-mounted display (HMD) or latency in display on the HMD have, however, kept AR from widespread usage in CAS. In this paper, the concept of the Varioscope AR, a lightweight head-mounted operating microscope used as a HMD, is introduced. The registration of the patient to the preoperative image data as well as preoperative planning take place on VISIT, a surgical navigation system developed at our hospital. Tracking of the HMD and stereoscopic visualisation take place on a separate POSIX.4 compliant realtime operating system running on PC hardware. While being in a very early stage of laboratory testing, we were able to overcome the technical problems described above; our work resulted in an AR visualisation system with an update rate of 6 Hz and a latency below 130 ms. First tests with 2D/3D registration have shown a match between 3D world coordinates and 2D HMD display coordinates in the range of 1.7 pixels. It integrates seamlessly into a surgical navigation system and provides a common focus for both virtual and real world objects. On the basis of our current results, we conclude that the Varioscope AR with the realtime visualisation unit is a major step towards the introduction of AR into clinical routine.

Hand-tracking technologies allow us to use our own hands to interact with real and virtual objects in Augmented Reality (AR) environments. This enables us to explore the interplay between hand-visualizations and hand-object interactions. We present a user study that examines the effect of different hand visualizations (invisible, transparent, opaque) on manipulation performance when interacting with real and virtual objects. For this, we implemented video-see-through (VST) AR-based virtual building blocks and hot wire tasks with real one-to-one counterparts that require participants to use gross and fine motor hand movements. To evaluate manipulation performance, we considered three measures: task completion time, number of collisions (hot wire task), and percentage of object displacement (building block task). Additionally, we explored the sense of agency and subjective impressions (preference, ease of interaction, successful and awkwardness) evoked by the different hand-visualizations. The results show that (1) manipulation performance is significantly higher when interacting with real objects compared to virtual ones, (2) invisible hands lead to fewer errors, higher agency, higher perceived success and ease of interaction during fine manipulation tasks with real objects, and (3) having some visualization of the virtual hands (transparent or opaque) overlayed on the real hands is preferred when manipulating virtual objects even when there are no significant performance improvements. Our empirical findings about the differences when interacting with real and virtual objects can aid hand visualization choices for manipulation tasks in AR.

Purpose Evacuation drills should be more realistic and interactive. Focusing on situational and audio-visual realities and scenario-based interactivity, the authors have developed a game-based evacuation drill (GBED) system that presents augmented reality (AR) materials on tablet computers. The paper's current research purpose is to improve visual reality (AR materials) in our GBED system. Design/methodology/approach The author's approach is to develop a new GBED system that superimposes digital objects [e.g. three-dimensional computer graphics (3DCG) elements] onto real-time vision using a marker-based AR library, a binocular opaque head-mounted display (HMD) and other current easily available technologies. Findings The findings from a trial experiment are that the new GBED system can improve visual reality and is appropriate for disaster education. However, a few problems remain for practical use. Research limitations/implications When using the GBED system, participants (i.e. HMD wearers) can suffer from 3D sickness and have difficulty in moving. These are important safety problems in HMD-based systems. Social implications The combination of AR and HMDs for GBEDs (i.e. integrating virtual and real worlds) will raise questions about its merits (pros and cons). Originality/value The originality of the research is the combination of AR and an HMD to a GBED, which has previously been realized primarily as simulation games in virtual worlds. The authors believe that our research has the potential to expand disaster education.

In this article, we present a client/server augmented reality (AR) system for viewing complex assembly models on mobile phones. Complex model information is located on a PC which takes care of all of the heavy AR tracking and rendering computation. A camera phone is used as a client to show this information, augmented on still images as animated view. The mobile phone interface also supports correct masking of the assembly pieces as they come together, as well as a graphics only viewing mode intended for better understanding of the assembly process. In addition to describing the mobile augmented assembly system we present results from two pilot user studies evaluating elements of the user interface. INTRODUCTION In order to remain competitive, today’s industry is employing a growing number of product variations with shorter and shorter life cycles, requiring efficient ways to handle the production planning and processing. Assembly line workers face more and more complex tasks and an increasing memory load is posed by the new production needs. Experienced workers may be able to handle several product variants at the same time, but new workers require training and guidance to handle the work tasks. Related activities such as maintenance and repair also require a lot of know-how of complex products. Guidance in assembly tasks is commonly provided by using printed blueprints or other documents. However, these are mainly two dimensional images or text while the real assembly task is three dimensional, making the relationship between parts hard to understand. Computer based technologies have been developed such as electronic guides, multimedia training material and interactive documents. However, these typically require the user to turn away from the assembly task to study a computer screen separate from the workspace. In our research we explore how augmented reality (AR) technology can be used to provide more intuitive guides to assist with assembly, repair and training tasks. With AR technology, synthetic objects can be merged with the user’s view of the real world so that the user can perform the assembly task without needing to look at a separate screen. The virtual objects appear in the correct position so that AR enables the creation of realistic looking 3D animated assembly “manuals”. Other researchers have developed prototype AR systems for supporting assembly tasks. These are typically based on head mounted displays (HMDs) connected to desktop or wearable computers. However, wearable computers are relatively expensive, they have a short battery life, and taking them into a harsh industrial environment is not always possible. Head mounted displays can also be bulky, they involve safety issues, and many workers are reluctant to wear them. To overcome these disadvantages, we are interested in developing a reliable mobile phone based AR assembly system. Today’s mobile phones have fast processors, significant memory, 3D graphics support, and high resolution displays. They contain various accessories that can be used for developing mobile AR applications such as good quality cameras, connectivity by Bluetooth, WLAN and GPRS, and various SAM.700.003.1155

One of the main problems of monoscopic video see-through augmented reality (AR) is the lack of reliable depth information. This makes it difficult to correctly represent complex spatial interactions between real and virtual objects, e.g., when rendering shadows. The most obvious graphical artifact is the incorrect display of the occlusion of virtual models by real objects. Since the graphical models are rendered opaquely over the camera image, they always appear to occlude all objects in the real environment, regardless of the actual spatial relationship. In this paper, we propose to utilize a new type of hardware in order to solve some of the basic challenges of AR rendering. We introduce a depth-of-flight range sensor into AR, which produces a 2D map of the distances to real objects in the environment. The distance map is registered with high resolution color images delivered by a digital video camera. When displaying the virtual models in AR, the distance map is used in order to decide whether the camera image or the virtual object is visible at any position. This way, the occlusion of virtual models by real objects can be correctly represented. Preliminary results obtained with our approach show that a useful occlusion handling based on time-of-flight range data is possible.

Augmented reality (AR) is anticipated for use in medical practice. However, virtual objects cannot be overlaid exactly on real objects using theoretical data. Therefore, this study is intended to determine the correction method to overlay a virtual object with real object accurately. Experimental results confirmed that differences of perceived depth position between real and virtual objects can be made negligible (within 1 mm on average) by correcting sizes of virtual objects such that they can be seen identically to the real object.

Augmented Reality and Mixed Reality technologies make us feel the real world and the virtual world are mixed with each other through visual matching. However, existing mixed reality contents using these technologies have a limitation that interact only with virtual objects and cannot interact with real objects. If a dynamic real object need to be influenced by a virtual object, or vice versa, illusion of Mixed Reality can be broken by the incongruity of the interaction. If these limitations are improved, real objects, which were always static, can operate dynamically and interact with virtual objects, so becomes difficult to distinguish between real objects and virtual objects. In this paper, we propose extended interactions in a mixed reality environment that can give illusion which is difficult to distinguish between real objects and virtual objects. And to confirm this, we implement authoring environment based Hololens.

The perceptual behavior of consumers on a product displayed in the market has a vital role in analyzing the importance given to that product. Therefore, various strategies have been developed to understand this consumer behavior in the selection of products. Immersive technologies like virtual, augmented, and mixed reality are among them. With the foremost feature of immersion in the virtual world and interaction of users with virtual objects, virtual reality, and augmented reality have unlocked their potential in research and a user-friendly tool for analyzing consumer behavior. In addition to these technologies, mixed reality also has a significant role in investigating consumer behavior. Studies on immersive technologies in food applications are vast, hence this review focuses on the applications of virtual, augmented, and mixed reality in the food selection behavior of consumers. The behavioral studies are elicited to develop new products based on consumer needs, to understand the shopping behavior in supermarkets for real-time usage, and to know the influence of emotions in a selection of products. The findings suggest that virtual, augmented, and mixed reality induce immersion of the users in food selection behavioral studies. Information on the technological advancements in the tools used for bringing immersion and interaction are discussed for its futuristic applications in food. Though immersive technology gives users a realistic virtual environment experience, its application in food systems is in the budding stage. More research on human response studies would contribute to its innovative and inevitable application in the future.

Endoscopic surgery causes less tissue injury compared to open surgical techniques, thus promoting more rapid recuperation and reduced post-operative pain. Endoscopy, however, allows the surgeon to visualise only the anatomical surface of the surgical site, with a relatively narrow field of view. Moreover, the 2D video captured by the conventional endoscope does not provide depth perception of the surgical scene. In this study, these limitations have been addressed with the development of an augmented reality (AR) system with stereoscopic visualisation. A phantom and its 3D CT model were used, respectively, to form the real and virtual parts of the AR. The virtual environment camera pose was tracked using algorithms for image feature detection, feature matching and Perspective-n-Point applied on the endoscopic image and the 3D virtual model-rendered image. The endoscope video frame- and the virtual model-rendered images were superimposed to form the AR composite view. The depth buffer (z-buffer) of the rendering window was further used to make a stereo pair of the AR image. The AR system produced a stereo composite view having well-aligned real and virtual components. The RMS error of the real and virtual image contours registration was 9.6 ± 6.7 mm. Correlation coefficients between the depth map from z-buffer and a depth camera was between 0.60 and 0.96 (p < 0.05). The AR system requires further improvement to be applicable at a higher frame rate of endoscope image acquisition. It also needs to include motion and deformation models when applied to animals or patients.

The Covid-19 pandemic has hit Indonesia since the beginning of 2020 and is still continuing. The education sector has experienced a considerable impact, face-to-face learning must be replaced with all-online activities. Many problems arise from online learning, such as inadequate infrastructure, an ineffective learning system and difficulties in understanding the material. Medical education has an impact on the current situation because most of the learning uses infrastructure and direct practice, it is necessary to have alternative learning methods that can improve the quality of learning. Currently, video conference media technology can assist learning activities so that instructors can still explain material to students through virtual media. For medical students who need practice and infrastructure facilities, this technology is still not enough to support their learning media. The idea came up “Application of Learning Module in Health Field based on Extended Reality (sub chapter: Augmented Reality)” This application combines Virtual Reality, Augmented Reality, and Mixed Reality. Augmented reality is a technology that is suitable to be implemented in medical learning because students do not need to prepare anything to perform simulations, just devices and internet networks. For feeding and drinking to the elderly, some items are needed to start the practicum, with this augmented reality there is no need to prepare all of these items, and also reduce contact with other people during a pandemic like this. Users can connect to each other in different devices and environments according to their respective devices. In this application, Augmented Reality acts as a technology that combines the real and virtual worlds by adding virtual objects into the real world. Users can use devices that have cameras such as cellphones or laptops so they can see virtual objects. This virtual object can be seen by all users and each user is able to interact with it in real time. As for the temporary test results, it was found that Augmented Reality has been tested and integrated with other immersive technologies with Web-XR. Interaction in Augmented Reality on Web-XR using a touch screen as well as several nursing SOP have been created and simulated using Augmented Reality technology. As for the final test in this final project, Augmented Reality technology based on WebXR has been running smoothly according to the specifications of the device used to open WebXR. If the device used to access WebXR has a high specification, then WebXR will run optimally, otherwise when the device specification is low, WebXR will not run optimally. The interaction used in WebXR-based Augmented Reality is touchscreen. The author tested this system to the user, the user here is a medical student. testing proves that this system is very helpful in terms of efficiency, users don't need to prepare tools repeatedly when they want to do simulations, just open WebXR and users can do the simulations provided. In testing the system, the author uses the PIECES framework (Performance, Information, Economics, Control and Security, Efficiency, Service) and produces an average score of 4.1. Then the user is categorized as satisfied with the system that was built.

Two main concepts of Head Mounted Displays (HMD) for augmented reality (AR) visualization exist, the optical and video-see through type. Several research groups have pursued both approaches for utilizing HMDs for computer aided surgery. While the hardware requirements for a video see through HMD to achieve acceptable time delay and frame rate seem to be enormous the clinical acceptance of such a device is doubtful from a practical point of view. Starting from previous work in displaying additional computer-generated graphics in operating microscopes, we have adapted a miniature head mounted operating microscope for AR by integrating two very small computer displays. To calibrate the projection parameters of this so called Varioscope AR we have used Tsai's Algorithm for camera calibration. Connection to a surgical navigation system was performed by defining an open interface to the control unit of the Varioscope AR. The control unit consists of a standard PC with a dual head graphics adapter to render and display the desired augmentation of the scene. We connected this control unit to a computer aided surgery (CAS) system by the TCP/IP interface. In this paper we present the control unit for the HMD and its software design. We tested two different optical tracking systems, the Flashpoint (Image Guided Technologies, Boulder, CO), which provided about 10 frames per second, and the Polaris (Northern Digital, Ontario, Canada) which provided at least 30 frames per second, both with a time delay of one frame.

Lately, mobile augmented reality (AR) has become very popular and is used for many commercial and product promotional activities. However, in almost all mobile AR applications, the user only views annotated information or the preset motion of the virtual object in an AR environment and is unable to interact with the virtual objects as if he/she were interacting with real objects in the real environment. In this paper, in an attempt to realize enhanced intuitive and realistic object manipulation in the mobile AR environment, we propose an integrated view-input AR interaction method, which integrates user device manipulation and virtual object manipulation. The method enables the user to hold a 3D virtual object by touching the displayed object on the 2D touch screen of a mobile device, and to move and rotate the object by moving and rotating the mobile device while viewing the held object by way of the 2D screen of the mobile device. Based on this concept, we implemented three types of integrated methods, namely the Rod, Center, and Touch methods, and conducted a user study to investigate the baseline performance metrics of the proposed method on an AR object manipulation task. The Rod method achieved the highest success rate (91%). Participants' feedback indicated that this is because the Rod method is the most natural, and evoked a fixed mental model that is conceivable in the real environment. These results indicated that visualizing the manipulation point on the screen and restricting the user's interactivity with virtual objects from the user's position of view based on a conceivable mental model would be able to aid the user to achieve precise manipulation.

Reality Skins enables mobile and large-scale virtual reality experiences, dynamically generated based on the user's environment. A head-mounted display (HMD) coupled with a depth camera is used to scan the user's surroundings: reconstruct geometry, infer floor plans, and detect objects and obstacles. From these elements we generate a Reality Skin, a 3D environment which replaces office or apartment walls with the corridors of a spaceship or underground tunnels, replacing chairs and desks, sofas and beds with crates and computer consoles, fungi and crumbling ancient statues. The placement of walls, furniture and objects in the Reality Skin attempts to approximate reality, such that the user can move around, and touch virtual objects with tactile feedback from real objects. Each possible reality skins world consists of objects, materials and custom scripts. Taking cues from the user's surroundings, we create a unique environment combining these building blocks, attempting to preserve the geometry and semantics of the real world.We tackle 3D environment generation as a constraint satisfaction problem, and break it into two parts: First, we use a Markov Chain Monte-Carlo optimization, over a simple 2D polygonal model, to infer the layout of the environment (the structure of the virtual world). Then, we populate the world with various objects and characters, attempting to satisfy geometric (virtual objects should align with objects in the environment), semantic (a virtual chair aligns with a real one), physical (avoid collisions, maintain stability) and other constraints. We find a discrete set of transformations for each object satisfying unary constraints, incorporate pairwise and higher-order constraints, and optimize globally using a very recent technique based on semidefinite relaxation.