Sports Visualization in the Wild: The Impact of Technical Factors on User Experience in Augmented Reality Sports Spectating.

The maturity of augmented reality (AR) technology allows for expansion into real-world applications, including visualizations for on-site sports spectating. However, it is crucial to understand the factors influencing user experience in AR applications. To optimize user experience, we conducted a user study where participants adjusted parameters to determine noticeable and disruptive values of latency, registration accuracy, and jitter using a mobile indirect AR prototype that simulates a rugby stadium experience. Our findings indicate that latency has the highest disruptive impact on users' experience, with registration accuracy following closely. Furthermore, when noticeable latency, registration accuracy, and jitter were combined, the user experience was negatively affected in a nonlinear, combinatorial manner. This suggests that addressing factors individually is necessary but not enough for successful user experiences. By understanding these factors, developers can optimize AR experiences when creating immersive AR sports experiences and other large-scale AR applications to ensure maximum enjoyment for users.

Feasibility and psychophysical effects of immersive virtual reality-based mirror therapy.

BACKGROUND: Virtual reality (VR) has been used as a technological medium to deliver mirror therapy interventions with people after stroke in numerous applications with promising results. The recent emergence of affordable, off-the-shelf head-mounted displays (like the Oculus Rift or HTC Vive) has opened the possibility for novel and cost-effective approaches for immersive mirror therapy interventions. We have developed one such system, ART-VR, which allows people after stroke to carry out a clinically-validated mirror therapy protocol in an immersive virtual environment and within a clinical setting. METHODS: A case cohort of 11 people with upper limb paresis following first time stroke at an in-patient rehabilitation facility received three interventions over a one week period. Participants carried out the BeST mirror therapy protocol using our immersive VR system as an adjunct therapy to their standard rehabilitation program. Our clinical feasibility study investigated intervention outcomes, virtual reality acceptance and user experience. RESULTS: The results show that the combination of an immersive VR system and mirror therapy protocol is feasible for clinical use. 9 out of 11 participants showed some improvement of their affected hand after the intervention. The vast majority of the participants (9/11) reported experiencing some psycho-physical effects, such as tingling or paraesthesia, in the affected limb during the intervention. CONCLUSIONS: Our findings show that immersive VR-based mirror therapy is feasible and shows effects comparable to those of conventional mirror therapy. Trial Registration Trial was registered with the ISRCTN Registry (ISRCTN34011164) on December 3, 2021, retrospectively.

Visualization Techniques in Augmented Reality: A Taxonomy, Methods and Patterns.

In recent years, the development of Augmented Reality (AR) frameworks made AR application development widely accessible to developers without AR expert background. With this development, new application fields for AR are on the rise. This comes with an increased need for visualization techniques that are suitable for a wide range of application areas. It becomes more important for a wider audience to gain a better understanding of existing AR visualization techniques. In this article we provide a taxonomy of existing works on visualization techniques in AR. The taxonomy aims to give researchers and developers without an in-depth background in Augmented Reality the information to successively apply visualization techniques in Augmented Reality environments. We also describe required components and methods and analyze common patterns.

How to Observe Users' Movements in Virtual Environments: Viewpoint Control in a Power Wheelchair Simulator.

OBJECTIVE: We describe a networked, two-user virtual reality (VR) power wheelchair (PWC) simulator system in which an actor (client) and an observer (clinician) meet. We then present a study with 15 observers (expert clinicians) evaluating the effect of three principal forms of viewpoint control (egocentric-egomotion, egocentric-tethered, and client-centric) on the observer's assessment of driving tasks in a virtual environment (VE). BACKGROUND: VR allows for the simulation and assessment of real-world tasks in a controlled, safe, and repeatable environment. Observing users' movement behavior in such a VE requires appropriate viewpoint control for the observer. The VR viewpoint user interface should allow an observer to make judgments equivalent or even superior to real-world situations. METHOD: A purpose-built VR PWC simulator was developed. In a series of PWC driving tasks, we measured the perceived ease of use and sense of presence of the observers and compared the virtual assessment with real-world "gold standard" scores, including confidence levels in judgments. RESULTS: Findings suggest that with more immersive techniques, such as egomotion and tethered egocentric viewpoints, judgments are both more accurate and more confident. The ability to walk and/or orbit around the view significantly affected the observers' sense of presence. CONCLUSION: Incorporating the observer into the VE, through egomotion, is an effective method for assessing users' behavior in VR with implications for the transferability of virtual experiences to the real world. APPLICATION: Our application domain serves as a representative example for tasks where the movement of users through a VE needs to be evaluated.

A Noninferiority Randomized Clinical Trial of the Use of the Smartphone-Based Health Applications IBDsmart and IBDoc in the Care of Inflammatory Bowel Disease Patients.

BACKGROUND: Providing timely follow-up care for patients with inflammatory bowel disease in remission is important but often difficult because of resource limitations. Using smartphones to communicate symptoms and biomarkers is a potential alternative. We aimed to compare outpatient management using 2 smartphone apps (IBDsmart for symptoms and IBDoc for fecal calprotectin monitoring) vs standard face-to-face care. We hypothesized noninferiority of quality of life and symptoms at 12 months plus a reduction in face-to-face appointments in the smartphone app group. METHODS: Inflammatory bowel disease outpatients (previously seen more often than annually) were randomized to smartphone app or standard face-to-face care over 12 months. Quality of life and symptoms were measured quarterly for 12 months. Acceptability was measured for gastroenterologists and patients at 12 months. RESULTS: One hundred people (73 Crohn's disease, 49 male, average age 35 years) consented and completed baseline questionnaires (50 in each group). Intention-to-treat and per-protocol analyses revealed noninferiority of quality of life and symptom scores at 12 months. Outpatient appointment numbers were reduced in smartphone app care (P < 0.001). There was no difference in number of surgical outpatient appointments or number of disease-related hospitalizations between groups. Adherence to IBDsmart (50% perfect adherence) was slightly better than adherence to IBDoc (30% perfect adherence). Good acceptability was reported among most gastroenterologists and patients. CONCLUSIONS: Remote symptom and fecal calprotectin monitoring is effective and acceptable. It also reduces the need for face-to-face outpatient appointments. Patients with mild-to-moderate disease who are not new diagnoses are ideal for this system. CLINICAL TRIAL REGISTRATION NUMBER: ACTRN12615000342516.

Immersive Telepresence and Remote Collaboration using Mobile and Wearable Devices.

The mobility and ubiquity of mobile head-mounted displays make them a promising platform for telepresence research as they allow for spontaneous and remote use cases not possible with stationary hardware. In this work we present a system that provides immersive telepresence and remote collaboration on mobile and wearable devices by building a live spherical panoramic representation of a user's environment that can be viewed in real time by a remote user who can independently choose the viewing direction. The remote user can then interact with this environment as if they were actually there through intuitive gesture-based interaction. Each user can obtain independent views within this environment by rotating their device, and their current field of view is shared to allow for simple coordination of viewpoints. We present several different approaches to create this shared live environment and discuss their implementation details, individual challenges, and performance on modern mobile hardware; by doing so we provide key insights into the design and implementation of next generation mobile telepresence systems, guiding future research in this domain. The results of a preliminary user study confirm the ability of our system to induce the desired sense of presence in its users.

Computerised mirror therapy with Augmented Reflection Technology for early stroke rehabilitation: clinical feasibility and integration as an adjunct therapy.

PURPOSE: New rehabilitation strategies for post-stroke upper limb rehabilitation employing visual stimulation show promising results, however, cost-efficient and clinically feasible ways to provide these interventions are still lacking. An integral step is to translate recent technological advances, such as in virtual and augmented reality, into therapeutic practice to improve outcomes for patients. This requires research on the adaptation of the technology for clinical use as well as on the appropriate guidelines and protocols for sustainable integration into therapeutic routines. Here, we present and evaluate a novel and affordable augmented reality system (Augmented Reflection Technology, ART) in combination with a validated mirror therapy protocol for upper limb rehabilitation after stroke. METHOD: We evaluated components of the therapeutic intervention, from the patients' and the therapists' points of view in a clinical feasibility study at a rehabilitation centre. We also assessed the integration of ART as an adjunct therapy for the clinical rehabilitation of subacute patients at two different hospitals. RESULTS: The results showed that the combination and application of the Berlin Protocol for Mirror Therapy together with ART was feasible for clinical use. This combination was integrated into the therapeutic plan of subacute stroke patients at the two clinical locations where the second part of this research was conducted. CONCLUSIONS: Our findings pave the way for using technology to provide mirror therapy in clinical settings and show potential for the more effective use of inpatient time and enhanced recoveries for patients. Implications for Rehabilitation Computerised Mirror Therapy is feasible for clinical use Augmented Reflection Technology can be integrated as an adjunctive therapeutic intervention for subacute stroke patients in an inpatient setting Virtual Rehabilitation devices such as Augmented Reflection Technology have considerable potential to enhance stroke rehabilitation.

Towards Pervasive Augmented Reality: Context-Awareness in Augmented Reality.

Augmented Reality is a technique that enables users to interact with their physical environment through the overlay of digital information. While being researched for decades, more recently, Augmented Reality moved out of the research labs and into the field. While most of the applications are used sporadically and for one particular task only, current and future scenarios will provide a continuous and multi-purpose user experience. Therefore, in this paper, we present the concept of Pervasive Augmented Reality, aiming to provide such an experience by sensing the user's current context and adapting the AR system based on the changing requirements and constraints. We present a taxonomy for Pervasive Augmented Reality and context-aware Augmented Reality, which classifies context sources and context targets relevant for implementing such a context-aware, continuous Augmented Reality experience. We further summarize existing approaches that contribute towards Pervasive Augmented Reality. Based our taxonomy and survey, we identify challenges for future research directions in Pervasive Augmented Reality.

Immersion factors affecting perception and behaviour in a virtual reality power wheelchair simulator.

Virtual Reality based driving simulators are increasingly used to train and assess users' abilities to operate vehicles in a controlled and safe way. For the development of those simulators it is important to identify and evaluate design factors affecting perception, behaviour, and driving performance. In an exemplary power wheelchair simulator setting we identified the three immersion factors display type (head-mounted display v monitor), ability to freely change the field of view (FOV), and the visualisation of the user's avatar as potentially affecting perception and behaviour. In a study with 72 participants we found all three factors affected the participants' sense of presence in the virtual environment. In particular the display type significantly affected both perceptual and behavioural measures whereas FOV only affected behavioural measures. Our findings could guide future Virtual Reality simulator designers to evoke targeted user behaviours and perceptions.

Real-Time Radiometric Compensation for Optical See-Through Head-Mounted Displays.

Optical see-through head-mounted displays are currently seeing a transition out of research labs towards the consumer-oriented market. However, whilst availability has improved and prices have decreased, the technology has not matured much. Most commercially available optical see-through head mounted displays follow a similar principle and use an optical combiner blending the physical environment with digital information. This approach yields problems as the colors for the overlaid digital information can not be correctly reproduced. The perceived pixel colors are always a result of the displayed pixel color and the color of the current physical environment seen through the head-mounted display. In this paper we present an initial approach for mitigating the effect of color-blending in optical see-through head-mounted displays by introducing a real-time radiometric compensation. Our approach is based on a novel prototype for an optical see-through head-mounted display that allows the capture of the current environment as seen by the user's eye. We present three different algorithms using this prototype to compensate color blending in real-time and with pixel-accuracy. We demonstrate the benefits and performance as well as the results of a user study. We see application for all common Augmented Reality scenarios but also for other areas such as Diminished Reality or supporting color-blind people.

Family history assessment for colorectal cancer (CRC) risk analysis - comparison of diagram- and questionnaire-based web interfaces.

BACKGROUND: Colorectal cancer (CRC) has a high incidence, especially in New Zealand. The reasons for this are unknown. While most cancers develop sporadically, a positive family history, determined by the number and age at diagnosis of affected first and second degree relatives with CRC is one of the major factors, which may increase an individual's lifetime risk. Before a patient can be enrolled in a surveillance program a detailed assessment and documentation of the family history is important but time consuming and often inaccurate. The documentation is usually paper-based. Our aim was therefore to develop and validate the usability and efficacy of a web-based family history assessment tool for CRC suitable for the general population. The tool was also to calculate the risk and make a recommendation for surveillance. METHODS: Two versions of an electronic assessment tool, diagram-based and questionnaire-based, were developed with the risk analysis and recommendations for surveillance based on the New Zealand Guidelines Group recommendations. Accuracy of our tool was tested prior to the study by comparing risk calculations based on family history by experienced gastroenterologists with the electronic assessment. The general public, visiting a local science fair were asked to use and comment on the usability of the two interfaces. RESULTS: Ninety people assessed and commented on the two interfaces. Both interfaces were effective in assessing the risk to develop CRC through their familial history for CRC. However, the questionnaire-based interface performed with significantly better satisfaction (p = 0.001) than the diagram-based interface. There was no difference in efficacy though. CONCLUSION: We conclude that a web-based questionnaire tool can assist in the accurate documentation and analysis of the family history relevant to determine the individual risk of CRC based on local guidelines. The calculator is now implemented and assessable through the web-page of a local charity for colorectal cancer awareness and integral part of the local general practitioners' e-referral system for colonic imaging.

Referred sensations elicited by video-mediated mirroring of hands.

Humans readily perceive ownership of a limb even when it is artificially induced as in the case of using a mirror reflection. However, mirror reflections are very constrained perceptions which do not allow transformations and varied contexts as often occurs in real life. The extent to which perceived limb ownership occurs with video-mediated manipulations is not known, particularly given the perception would no longer be a precise copy (reflection) of a person's own limb. The present study directly compared referred sensations of the limbs with the use of a mirror reflection to those obtained with a new video-mediated setup to assess perceived ownership. Manipulations that could not be performed with a standard mirror reflection, such as reversal of the spatial positions of the limbs, were also investigated to examine how far the perceived ownership effects could be pushed. Across a series of experiments, data on the quality, intensity and location of referred sensations were collected and analyzed together with measures of hand ownership and participants' experience of the two setups. Results reveal that participants felt referred sensations in both the optical and the video-mediated setup, and that video-mediated manipulations of hand-position reversals produced equal to stronger effects of ownership compared with the mirror reflection. These findings open up new possibilities for scientific experimentation and therapy that are discussed in the paper.