Comparing Non-Visual and Visual Guidance Methods for Narrow Field of View Augmented Reality Displays

Three-Dimensional Position Presentation via Head and Waist Vibrotactile Arrays

This article introduces a novel system designed to convey the three-dimensional positions surrounding the user. The system incorporates circumferential vibrotactile arrays strategically positioned on both the user's head and waist. Through the synergy of this two-dimensional arrangement and modulations in vibration amplitude, the system adeptly presents comprehensive three-dimensional positional information. Two prototypes, namely a spherical model and a cylindrical model, were employed as mappings between three-dimensional positions and vibration amplitudes. In Experiment 1, we evaluated the system's performance in indicating positions in depth, orientation, and height. Notably, discrimination rates for depth (Task 1) and orientation (Task 2) were 60% and 54%, respectively. Regarding height discrimination in the head-to-waist condition (Tasks 3 and 4), the cylindrical model outperformed the spherical model (54% and 52% vs. 32% and 36%). Conversely, in the head-above and waist-below condition (Task 5), the cylindrical model achieved a discrimination rate of 45%, while the spherical model did not. In Experiment 2, we explored the use of the cylindrical model to convey a moving three-dimensional position. The results showed an impressive 81% correct response rate, affirming the system's effectiveness in presenting three-dimensional motion stimuli.

Exploring Bimanual Haptic Feedback for Spatial Search in Virtual Reality

Spatial search tasks are common and crucial in many Virtual Reality (VR) applications. Traditional methods to enhance the performance of spatial search often employ sensory cues such as visual, auditory, or haptic feedback. However, the design and use of bimanual haptic feedback with two VR controllers for spatial search in VR remains largely unexplored. In this work, we explored bimanual haptic feedback with various combinations of haptic properties, where four types of bimanual haptic feedback were designed, for spatial search tasks in VR. Two experiments were designed to evaluate the effectiveness of bimanual haptic feedback on spatial direction guidance and search in VR. The results from the first experiment reveal that our proposed bimanual haptic schemes significantly enhanced the recognition of spatial directions in terms of accuracy and speed compared to spatial audio feedback. The second experiment's findings suggest that the performance of bimanual haptic feedback was comparable to or even better than the visual arrow, especially in reducing the angle of head movement and enhancing searching targets behind the participants, which was supported by subjective feedback as well. Based on these findings, we have derived a set of design recommendations for spatial search using bimanual haptic feedback in VR.

Evaluating Augmented Reality Landmark Cues and Frame of Reference Displays with Virtual Reality

Daily travel usually demands navigation on foot across a variety of different application domains, including tasks like search and rescue or commuting. Head-mounted augmented reality (AR) displays provide a preview of future navigation systems on foot, but designing them is still an open problem. In this paper, we look at two choices that such AR systems can make for navigation: 1) whether to denote landmarks with AR cues and 2) how to convey navigation instructions. Specifically, instructions can be given via a head-referenced display (screen-fixed frame of reference) or by giving directions fixed to global positions in the world (world-fixed frame of reference). Given limitations with the tracking stability, field of view, and brightness of most currently available head-mounted AR displays for lengthy routes outdoors, we decided to simulate these conditions in virtual reality. In the current study, participants navigated an urban virtual environment and their spatial knowledge acquisition was assessed. We experimented with whether or not landmarks in the environment were cued, as well as how navigation instructions were displayed (i.e., via screen-fixed or world-fixed directions). We found that the world-fixed frame of reference resulted in better spatial learning when there were no landmarks cued; adding AR landmark cues marginally improved spatial learning in the screen-fixed condition. These benefits in learning were also correlated with participants' reported sense of direction. Our findings have implications for the design of future cognition-driven navigation systems.

Labeling Out-of-View Objects in Immersive Analytics to Support Situated Visual Searching

Augmented Reality (AR) embeds digital information into objects of the physical world. Data can be shown in-situ, thereby enabling real-time visual comparisons and object search in real-life user tasks, such as comparing products and looking up scores in a sports game. While there have been studies on designing AR interfaces for situated information retrieval, there has only been limited research on AR object labeling for visual search tasks in the spatial environment. In this article, we identify and categorize different design aspects in AR label design and report on a formal user study on labels for out-of-view objects to support visual search tasks in AR. We design three visualization techniques for out-of-view object labeling in AR, which respectively encode the relative physical position (height-encoded), the rotational direction (angle-encoded), and the label values (value-encoded) of the objects. We further implement two traditional in-view object labeling techniques, where labels are placed either next to the respective objects (situated) or at the edge of the AR FoV (boundary). We evaluate these five different label conditions in three visual search tasks for static objects. Our study shows that out-of-view object labels are beneficial when searching for objects outside the FoV, spatial orientation, and when comparing multiple spatially sparse objects. Angle-encoded labels with directional cues of the surrounding objects have the overall best performance with the highest user satisfaction. We discuss the implications of our findings for future immersive AR interface design.

User's image perception improved strategy and application of augmented reality systems in smart medical care: A review

BACKGROUND

Augmented reality (AR) is a new human-computer interaction technology that combines virtual reality, computer vision, and computer networks. With the rapid advancement of the medical field towards intelligence and data visualisation, AR systems are becoming increasingly popular in the medical field because they can provide doctors with clear enough medical images and accurate image navigation in practical applications. However, it has been discovered that different display types of AR systems have different effects on doctors' perception of the image after virtual-real fusion during the actual medical application. If doctors cannot correctly perceive the image, they may be unable to correctly match the virtual information with the real world, which will have a significant impact on their ability to recognise complex structures.

METHODS

This paper uses Citespace, a literature analysis tool, to visualise and analyse the research hotspots when AR systems are used in the medical field.

RESULTS

A visual analysis of the 1163 articles retrieved from the Web of Science Core Collection database reveals that display technology and visualisation technology are the key research directions of AR systems at the moment.

CONCLUSION

This paper categorises AR systems based on their display principles, reviews current image perception optimisation schemes for various types of systems, and analyses and compares different display types of AR systems based on their practical applications in the field of smart medical care so that doctors can select the appropriate display types based on different application scenarios. Finally, the future development direction of AR display technology is anticipated in order for AR technology to be more effectively applied in the field of smart medical care. The advancement of display technology for AR systems is critical for their use in the medical field, and the advantages and disadvantages of various display types should be considered in different application scenarios to select the best AR system.

Multisensory Proximity and Transition Cues for Improving Target Awareness in Narrow Field of View Augmented Reality Displays

Augmented reality applications allow users to enrich their real surroundings with additional digital content. However, due to the limited field of view of augmented reality devices, it can sometimes be difficult to become aware of newly emerging information inside or outside the field of view. Typical visual conflicts like clutter and occlusion of augmentations occur and can be further aggravated especially in the context of dense information spaces. In this article, we evaluate how multisensory cue combinations can improve the awareness for moving out-of-view objects in narrow field of view augmented reality displays. We distinguish between proximity and transition cues in either visual, auditory or tactile manner. Proximity cues are intended to enhance spatial awareness of approaching out-of-view objects while transition cues inform the user that the object just entered the field of view. In study 1, user preference was determined for 6 different cue combinations via forced-choice decisions. In study 2, the 3 most preferred modes were then evaluated with respect to performance and awareness measures in a divided attention reaction task. Both studies were conducted under varying noise levels. We show that on average the Visual-Tactile combination leads to 63% and Audio-Tactile to 65% faster reactions to incoming out-of-view augmentations than their Visual-Audio counterpart, indicating a high usefulness of tactile transition cues. We further show a detrimental effect of visual and audio noise on performance when feedback included visual proximity cues. Based on these results, we make recommendations to determine which cue combination is appropriate for which application.

User Behavior Adaptive AR Guidance for Wayfinding and Tasks Completion

Augmented reality (AR) is widely used to guide users when performing complex tasks, for example, in education or industry. Sometimes, these tasks are a succession of subtasks, possibly distant from each other. This can happen, for instance, in inspection operations, where AR devices can give instructions about subtasks to perform in several rooms. In this case, AR guidance is both needed to indicate where to head to perform the subtasks and to instruct the user about how to perform these subtasks. In this paper, we propose an approach based on user activity detection. An AR device displays the guidance for wayfinding when current user activity suggests it is needed. We designed the first prototype on a head-mounted display using a neural network for user activity detection and compared it with two other guidance temporality strategies, in terms of efficiency and user preferences. Our results show that the most efficient guidance temporality depends on user familiarity with the AR display. While our proposed guidance has not proven to be more efficient than the other two, our experiment hints toward several improvements of our prototype, which is a first step in the direction of efficient guidance for both wayfinding and complex task completion.