Text Input in Virtual Reality: A Preliminary Evaluation of the Drum-Like VR Keyboard

An affordable and immersive virtual reality-based exercise therapy in forward head posture

Forward Head Posture (FHP) is one of the most commonly occurring musculoskeletal abnormalities. Despite exercise therapy being an effective approach for FHP treatment, it can be long, monotonous, and tedious. Virtual reality (VR) can be used as an innovative solution to address these challenges. We designed an affordable and immersive VR-based exercise therapy (VRET) system for FHP correction. The VRET contents (i.e., exercises and VR scenarios) were determined by physiotherapists and game designers at the focus group meetings. Hardware requirements include a VR box, smartphone, and sensors (i.e., a smartphone accelerometer and an affordable Inertial Measurement Unit (IMU)) to measure head motions and transfer them via Wi-Fi to the VRET system. The IMU was designed using the MPU6050, Arduino Nano, and ESP8266-01S. Gwet's AC1, Game Experience Questionnaires (GEQ), and System Usability Scale (SUS) were used to measure intra-rater reliability, user experience, and system usability, respectively. The determined exercises, including Capital Flexion-Extension and Chin Tuck, were designed in the form of a shooting game. A physiotherapist and twenty-one FHP individuals took part in evaluating the system. High precision was obtained for the designed IMU (i.e., pitch and roll < 0.1° and yaw < 1.3 °). Gwet's AC1 and SUS results showed very good intra-rater reliability (coefficient = 0.892) and excellent usability (score = 87.14), respectively. According to the mean scores of the GEQ, participants were confident about competence, immersion, flow, and positive affect components. The development of low-cost VRET systems for FHP correction is a step towards facilitating rehabilitation challenges by providing positive experiences for users as well as helping them perform therapeutic exercises correctly.

A Comparative Study of the Typing Performance of Two Mid-Air Text Input Methods in Virtual Environments

Inputting text is a prevalent requirement among various virtual reality (VR) applications, including VR-based remote collaboration. In order to eliminate the need for complex rules and handheld devices for typing within virtual environments, researchers have proposed two mid-air input methods-the trace and tap methods. However, the specific impact of these input methods on performance in VR remains unknown. In this study, typing tasks were used to compare the performance, subjective report, and cognitive load of two mid-air input methods in VR. While the trace input method was more efficient and novel, it also entailed greater frustration and cognitive workload. Fortunately, the levels of frustration and cognitive load associated with the trace input method could be reduced to the same level as those of the tap input method via familiarity with VR. These findings could aid the design of virtual input methods, particularly for VR applications with varying text input demands.

CrowbarLimbs: A Fatigue-Reducing Virtual Reality Text Entry Metaphor

Text entry remains challenging in virtual environments, where users may quickly experience physical fatigue in some body parts using existing methods. In this paper, we propose "CrowbarLimbs," a novel virtual reality (VR) text entry metaphor with two deformable extended virtual limbs. By using a crowbar-like metaphor and placing the virtual keyboard at a user-preferred location based on the user's physical stature, our method can assist the user in placing their hands and arms in a comfortable posture, thus effectively reducing the physical fatigue in various body parts, such as hands, wrists, and elbows. In an initial user study, we found that CrowbarLimbs achieved text entry speed, accuracy, and system usability comparable to those of previous VR typing methods. To investigate the proposed metaphor in more depth, we further conducted two additional user studies to explore the ergonomically user-friendly shapes of CrowbarLimbs and virtual keyboard locations. The experimental results indicate that the shapes of CrowbarLimbs have significant effects on the fatigue ratings in various body parts and text entry speed. Furthermore, placing the virtual keyboard near the user and at half their height can lead to a satisfactory text entry rate of 28.37 words per minute.

Efficient Flower Text Entry in Virtual Reality

Text entry is a frequently used task in virtual reality (VR) applications, and controller is the most common interactive device in current VR systems. However, in terms of typing speed, there is still a gap between the existing controller-based text entry techniques and using a physical keyboard in reality, so it is important to improve the efficiency of the controller-based text entry. In this paper, we introduce Flower Text Entry, a single-controller text entry method based on a newly designed flower-shaped keyboard using hand 3D translation interaction for letters selection. We conduct user studies to optimize the keyboard design and the mapping between the interaction and selection, so as to evaluate our method. The results show that our method has high typing speed, lower error rate, and is very friendly to novices compared with the state-of-the-art controller-based text entry methods. After a short training, the novice group can type at 17.65 words per minute (WPM), and the potential expert group can type at 22.97 WPM. The highest typing speed is up to 30.80 WPM achieved by a potential expert participant.

The study of virtual reality influence on the process of professional training of miners

Virtual reality technologies are actively applied for the organization of professional training in various industries, as well as in distance learning. However, numerous studies show the presence of a large number of negative factors that limit the effectiveness of using these technologies (united by the concept of "cybersickness"). The study, identification and reduction in the influence of these negative factors will increase the immersiveness and quality of the professional training process. Within the framework of this study, several hypotheses have been put forward regarding the negative and positive impact of VR technologies on the process of professional training, the coal and mining industry has been chosen as the subject area. Thus, the problem of effective training of miners for activities in regular and emergency situations is considered, in the latter case, VR technologies would allow forming the necessary set of skills and knowledge about actions in emergency situations. To confirm the declared hypotheses, an experimental group of 30 people was formed, corresponding to the trained miners by age characteristics. Based on the analysis, a list of quantitative and qualitative metrics for evaluating interaction with virtual reality was formed, the software of virtual scenes for two tasks (moving simple objects and a set of exercises in a virtual mine) was developed. The experimental group repeatedly performed these exercises, which allowed us to analyze the dynamics of changes in the average values of quantitative and qualitative metrics. The data obtained were processed by statistical tests (Shapiro-Wilk, Kruskal-Wallis, Mann-Whitney), which allowed us to assess the impact of the selected configurations (with and without VR) and the number of attempts on the selected metrics. The obtained results partially or completely confirmed the declared hypotheses and allowed us to form a list of recommendations for the organization of high-quality professional training using virtual reality technologies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10055-022-00687-7.

Investigating the Performance of Gesture-Based Input for Mid-Air Text Entry in a Virtual Environment: A Comparison of Hand-Up versus Hand-Down Postures

Although the interaction technology for virtual reality (VR) systems has evolved significantly over the past years, the text input efficiency in the virtual environment is still an ongoing problem. We deployed a word-gesture text entry technology based on gesture recognition in the virtual environment. This study aimed to investigate the performance of the word-gesture text entry technology with different input postures and VR experiences in the virtual environment. The study revealed that the VR experience (how long or how often using VR) had little effect on input performance. The hand-up posture has a better input performance when using word-gesture text entry technology in a virtual environment. In addition, the study found that the perceived exertion to complete the text input with word-gesture text entry technology was relatively high. Furthermore, the typing accuracy and perceived usability for using the hand-up posture were obviously higher than that for the hand-down posture. The hand-up posture also had less task workload than the hand-down posture. This paper supports that the word-gesture text entry technology with hand-up posture has greater application potential than hand-down posture.