New Method to Measure End-to-End Delay of Virtual Reality

This paper describes a study aimed at developing and applying a method for comparing the user experience (UX) of virtual reality (VR) systems, in order to identify aspects that differentiate VR systems from a user perspective as well as aspects that users consider important when selecting a VR system. A within-subjects study was conducted, in which twelve participants played a VR game using four different VR systems (i.e., VR headsets and hand controllers). The UX was evaluated through semi-structured interviews and questionnaires. Headset comfort, fit, and perceived image quality as well as unrestricted mobility (i.e., untethered headsets) were identified as important aspects for the UX. Hand controllers that allowed more natural interaction were generally preferred. Image sharpness and headset comfort were considered the most important aspects for selecting a VR system. The study demonstrated that the method can be applied and generate insights into the UX of VR systems.

A wide variety of techniques for manipulating 3D objects in VR (Virtual Reality) systems have been implemented recently. But the shortcomings of the present interaction devices limit the types of manipulation that the user can perform in the virtual world. In this paper an interaction device that enables the user to interact with the virtual environment with different gestures is presented. By measuring the joint angles of the individual fingers with fiber optic sensors and tracking the relative position and orientation of the palm with AC (Alternating Current) pulsed magnetic tracker, the proposed interaction device can track an enormous variety of gestures and give the VR system remarkably rich expressive power. The relationship between the output of the fiber optic sensor and the actual flexure angle is studied. A digital phase sensitive detector is constructed and an iteration algorithm is used to extract the amplitudes of the received signals of the magnetoresistive sensors. The algorithm to calculate the spherical coordinates from the output of the accelerometers and magnetoresistive sensors is deducted. The design of the proposed interaction device and the experiment result are also presented.

In recent years virtual environments (VEs) have become more and more popular and widespread due to the requirements of numerous application areas in particular in the 3D city visualization domain. Virtual reality (VR) systems, which make use of tracking technologies and stereoscopic projections of three-dimensional synthetic worlds, support better exploration of complex datasets. However, due to the limited interaction space usually provided by the range of the tracking sensors, users can explore only a portion of the virtual environment (VE). Redirected walking allows users to walk through large-scale immersive virtual environments (IVEs) such as virtual city models, while physically remaining in a reasonably small workspace by intentionally injecting scene motion into the IVE. With redirected walking users are guided on physical paths that may differ from the paths they perceive in the virtual world. The authors have conducted experiments in order to quantify how much humans can unknowingly be redirected. In this chapter they present the results of this study and the implications for virtual locomotion user interfaces that allow users to view arbitrary real world locations, before the users actually travel there in a natural environment.

Digital restoration of fragmentary human skeletal remains: Testing the feasibility of virtual reality

Background and Purpose: Repetitive practice improves function and facilitates cortical plasticity after stroke. Virtual reality (VR) systems have the potential to provide motivating and safe repetitive practice with minimal supervision. The purpose of this case study is to look at the effect of a VR system, activated by surface electromyography of dorsiflexors and plantarflexors, on gait velocity, function, and kinematics. Method: The first person randomized to the treatment group of a larger study was chosen for this case. She was 51 years old and 9 months poststroke. She received treatment 3 times per week for 8 weeks. Each 60-minute session consisted of both structured lower extremity exercise and VR ankle activities. Results: After intervention, the subject demonstrated increased gait speed and decreased time to perform the modified Emory Functional Ambulation Profile. Gait kinematics demonstrated improved ankle motion and plantarflexion moments at push off. Discussion: The improved gait speed, possibly due to increased ankle plantarflexion motion and moments, resulted in a more normalized trailing limb posture. This case study suggests that ankle to computer VR systems may help stroke patients improve gait function. This VR system has potential as an adjunctive therapy or home program requiring minimal supervision.

With the rapid development of science and technology, virtual reality (VR) systems have developed rapidly. VR systems can be applied in many fields such as education, medical, military, and probing. According to the survey, the VR system will have a delay in the process of acquisition, transmission and processing, and more than 40% of the human body will have motion sickness after experiencing VR. The cause of motion sickness is delay. Accurate measurement of delays therefore helps to resolve motion sickness in the virtual world and provides guidance for the upgrade of these systems. In response to the existing problems, our research team designed a low-cost, high-performance experimental equipment that uses a single-chip microcomputer and a PIN photodiode as the hardware core of the delay detection device. The light intensity changes are used to determine the start and end of the detection. The algorithm calculates the delay time of the VR device.

Purpose Immersive Virtual Reality (VR) systems allow for highly repetitive tasks to be performed within a virtual environment that increases practice in home environments. VR can increase access to rehabilitation by reducing access barriers. However, rehabilitation outcomes between immersive VR systems and conventional physical rehabilitation are not well understood. The purpose of this case study was to assess the use of a custom clinically based VR simulation for testing gross hand dexterity with an individual with chronic stroke. Materials and methods The participant performed the box and blocks test (BBT) in an immersive VR environment and a physical environment. Three trials of the BBT were performed with their less-affected and affected hands each in both environments while measuring cortical activity using fNIRS. Rests were given between trials and environment conditions. Results Our results show that there was no statistical difference in the number of blocks moved between the physical and VR BBT for both the affected and less-affected hands. Furthermore, our results also indicate no statistically significant difference between the physical BBT and VR BBT conditions on contralateral motor cortex activation, suggesting that cortical involvement is comparable between physical and VR conditions. Conclusions These results suggest that an immersive VR system may be able to elicit functional and motor cortex activations that are comparable to the conventional physical BBT. Importantly, these findings highlights the potential benefits of VR therapy as a remote therapy intervention and/or to increase the effectiveness and practicality of current in-person rehabilitation programs. Implications for rehabilitation These findings highlight the potential benefits of immersive virtual reality as a remote therapy intervention. Immersive virtual reality use has potential benefits to increase the effectiveness and practicality of current in-person rehabilitation programs.

In order to improve the efficiency of information acquisition and task selection in Virtual Reality (VR) systems, enhance the interactive experience, and reduce cognitive load for users, it is crucial to effectively organize and leverage user cognitive psychology and design elements during the VR scene design phase. This paper focuses on analyzing the low cognitive load requirements of users and the need for a satisfactory user perceptual experience based on the cognitive resource theory. We propose a method for optimizing the design of VR system scenario tasks under low cognitive load requirements. By utilizing human-computer hybrid intelligent assistance for predicting user cognitive load and incorporating intelligent optimization genetic algorithms into the optimization of VR system design elements, we aim to minimize cognitive load as the objective function based on the principle of low cognitive load. Important knowledge granularity nodes are used as fitness functions in the optimization process of VR system design resource elements. An application study is conducted, combining the multi-channel cognition in a smart city VR system task information interface, to optimize the system resource features. The study validates and compares the solutions obtained through traditional design processes and the solutions optimized by the method proposed in this paper, using virtual reality eye-tracking experiments for the same design task requirements in VR systems. The results demonstrate that users experience lower cognitive load and better task operation experience when interacting with the optimized solutions proposed in this paper. Therefore, the optimization method studied in this paper can serve as a reference for the construction of virtual reality systems.

The computers nowadays are powerful enough to make the virtual reality technology more practical. Virtual reality is expected to have a bright future due to the rise of several virtual reality head mounted device such as low cost Google Cardboard, Samsung Gear VR, Oculus, HTC Vive and many others. Since virtual reality had been growing fast in this few years thus it is necessary to explore new approaches for user to interact with the virtual reality more naturally. It is an important research in HCI to make the interactions with computers to be as natural as the interaction between humans. One of the approaches is to allow user to interact with the virtual reality through gesture and speech input. This paper presents a virtual reality environment with multimodal interaction technique. It allows user to interact with the virtual reality system with the static and stroke hand gesture along with speech. This multimodal interaction technique is able to perform few functions such as select, move, scale, rotate, copy, mirror, delete, check the shape, check and change the colour of an object.

The Reality of Virtual Reality in Echocardiography Education?

Virtual reality (VR) entails the use of advanced technologies, including computers and various multimedia peripherals, to produce a simulated (that is, virtual) environment that users perceive as comparable to real world objects and events. In recent years, virtual reality technologies have begun to be used as an assessment and treatment tool in occupational therapy, in part because of the ability to create environments that provide patients with opportunities to engage in meaningful, purposeful tasks that are related to real-life interests and activities. The objective of this study was to determine the suitability and feasibility of using a PC-based, non-immersive, VR system (that is, a system in which the user has a reduced sense of actual presence in and control over the simulated environment) for training individuals with unilateral spatial neglect to cross streets in a safe and vigilant manner. A virtual environment, consisting of a typical city street, was programmed using Superscape's 3D-Webmaster, a 3D web-authoring tool. Twelve subjects, aged 55 to 75 years, participated in the initial feasibility study and, to date, a further eight subjects have participated in the intervention study. Six of the initial subjects and all eight of the intervention subjects had sustained a right hemispheric stroke at least 6 weeks prior to the study. The remaining subjects were healthy age-matched adults who were independently mobile and had no difficulty in crossing streets. The results show that this virtual environment was suitable in both its cognitive and motor demands for the targeted population and indicate that the virtual reality training is likely to prove beneficial to people who have difficulty with crossing streets. The generalizability of these results, and recommendations regarding the use of virtual reality as an occupational therapy intervention, must be substantiated by further studies using a range of VR platforms with people with different cognitive and motor disabilities.

Generally, a virtual reality (VR) system cannot provide the realistic sound formed by the multi-channel audio signals to a user with the stereo headphone environment. In addition, the VR system has a gap between the visual scene and the sound because it supplies the audio signal having only a constant sound scene without respect to the change of the user's position. To solve these problems, we introduce the sound scene control of binaural sound. Binaural sound is a stereo realistic sound that can be generated by convolving a 10.1 channel audio signal with a head related transfer function (HRTF) coefficients which features all the paths from the multi-channel speaker layout to the ears in free space. However, since a binaural sound is generated using a fixed multi-channel layout and HRTF coefficients, the binaural sound has a constant sound scene and cannot reflect the user's movements. So, we apply the sound scene control scheme that modifies the binaural sound to allow the user's movement in the VR system. Initially, a multichannel layout is re-created according to the user's azimuth change and the original multi-channel signal is mapped to a new ultra multi-channel layout using a constant power panning law. Secondly, the sound level of the new multichannel audio signal is controlled by the user's distance change, using the characteristics of the sound level inversely proportional to distance. Finally, the final multi-channel audio signal is convolved with the HRTF coefficients to produce a binaural sound with the controlled sound scene. As a result, the proposed realistic audio sound generation method allows the current VR system to provide true VR service without distinction between the visual scenes and sounds.

The evolution of Virtual Reality (VR) technology has contributed in all fields, including psychology. This evolution involves improvements in hardware and software allowing more immersive experiences. In a VR environment users can perceive the sensation of presence and feel immersed. These sensations are possible using VR devices as HMDs. Nowadays, the development of the HMDs has focused on improving their technical features to offer full immersion. In psychology, VR environments are research tools because they allow the use of new paradigms that are not possible to employ in a real environment. There are some applications for assessing spatial memory that use basic methods of HCI. However, VR systems that incorporate stereoscopy and physical movement have not yet been exploited in psychology. In this thesis, a novel VR system combining immersive, interactive and motion features was developed. This system was used for the assessment of the spatial memory and the evaluation of depth perception. For this system, a virtual maze task was designed and implemented. In this system, two different types of interaction were integrated: a locomotion-based interaction pedaling a fixed bicycle (condition1), and a stationary interaction using a gamepad (condition2). This system integrated two types of display systems: 1) The Oculus Rift; 2) A large stereo screen. Two studies were designed to determine the efficacy of the VR system using physical movement and immersion. The first study (N=89) assessed the spatial short term memory using the Oculus Rift and the two types of interaction The results showed that there were statistically significant differences between both conditions. The participants who performed the condition2 got better performance than participants who performed the condition1. However, there were no statistically significant differences in satisfaction and interaction scores between both conditions. The performance on the task correlated with the performance on other classical neuropsychological tests, revealing a verisimilitude between them. The second study (N=59) involved participants who had and who had not stereopsis. This study assessed the depth perception by comparing the two display systems. The participants performed the task using the condition2. The results showed that the different features of the display system did not influence the performance on the task between the participants with and without stereopsis. Statistically significant differences were found in favor of the HMD between the two conditions and between the two groups of participants regard to depth perception. The participants who did not have stereopsis and could not perceive the depth when they used other display systems (e.g. CAVE); however, they had the illusion of depth perception when they used the Oculus Rift. The study suggests that for the people who did not have stereopsis, the head tracking largely influences the 3D experience. The statistical results of both studies have proven that the VR system developed for this research is an appropriate tool to assess the spatial short-term memory and the depth perception. Therefore, the VR systems that combine full immersion, interaction and movement can be a helpful tool for the assessment of human cognitive processes as the memory. General conclusions from these studies are: 1) The VR technology and immersion provided by current HMDs are appropriate tools for psychological applications, in particular, the assessment of spatial short-term memory; 2) A VR system like the one presented in this thesis could be used as a tool to assess or train adults in skills related to spatial short-term memory; 3) The two types of interaction (condition1 and condition2) used for navigation within the virtual maze could be helpful to use with different collectives; 4) The Oculus Rift allows that the users without stereopsis can perceive the depth perception of 3D objects and have rich 3D experiences.

Advances in Virtual Reality (VR) systems, Intelligent Tutoring Systems and Agent Technology make it possible to design and develop Virtual Training Environments (VTEs), where the trainees can immerse themselves and interact directly with the learning domain. This paper presents the Interaction Specification Workspace (ISW) architecture for the specification and design of virtual environments for training purposes. ISW architecture provides the interaction designer with the capability to specify the training interaction with the virtual environment using the Virtual Reality Multi Flow Graph (VR-MFG) as the underlying interaction specification model. ISW implements a design space, where the processes of interaction specification and design of VTEs take place inside a three-dimensional virtual environment, the objects of which are tools by themselves. Inside this workspace, the designer can associate the abstract objects (the components of the VR-MFG) with “actual” objects of the target virtual environment (kept in a “world” database) and apply a number of agent templates with training capabilities.

The safety features of a virtual reality (VR) system were studied from the physiological and psychological viewpoint within an ergonomic framework. The VR was developed for constructing a novel online hospital system using a virtual environment called “Hyper Hospital,” a medical care system constructed in a distributed manner using VR as a human interface to the electronic information network. Ten healthy young male subjects were exposed to the VR system with different intensities of physiological and psychological stimuli. As a psychological stimuli, they underwent an interview with a virtual (electronic) “nurse.” The interview session was divided into two parts, namely one of low stress and one of high stress. Following each interview session, subjects were exposed to a moving scene (similar to a roller coaster ride) of varying intensities. The responses were compared with those obtained in the control experiments in which an environmental video (just a seaside scene) was presented. None of the physiological or psychological parameters (such as urinary catecholamine release, heart rate, blood pressure, etc.) indicated that significant fatigue occurred. This implies that fatigue was not induced by the usage of our VR system when compared with the results of the control experiments.