针对可穿戴设备的虚拟鼠标

人类对外界的感知和联系一直是人类活动研究的重点。许多产品和技术都可以结合,如最近非常流行的虚拟现实,就是将虚拟现实和残疾人的健康保障组合在一起。早期的虚拟显示设备都带有传感器,但用这些传感器进行交互对于残疾人来说十分困难。主要原因是当用户使用输入设备（键盘、鼠标、遥控器）控制虚拟现实设备的时候,操作十分复杂,没有外在的帮助,有运动障碍的人无法正常使用。为了解决以上问题,提出了用虚拟鼠标取代传统鼠标,将键盘、鼠标、遥控器的功能三合一,以可穿戴眼镜作为显示的媒介设备,简化交互过程。设计原则是通过使用一个按键,用户就可以与安装在虚拟眼镜上的系统进行交互,同时不需要很大的手指力量和手指活动幅度。我们控制变量的方式设计对比实验来评估该系统。该系统的后期测验证明了提出的系统的有效性和可靠性,而且系统整体设计十分完备。     

A study of cybersickness and sensory conflict theory using a motion-coupled virtual reality system

Sensory conflict theory explains that motion sickness in virtual reality (VR) systems can be caused due to the mismatch between visual and vestibular senses. This study examines whether coupling physical motions to visual stimuli in VR could reduce this discomfort. A motion-coupled VR system developed on a motion platform, providing vestibular cues to supplement visual roll from a head-mounted display (HMD), was used. Three conditions were tested: visual rotation only (stationary), visual-physical motion synchronised (synchronous), and vestibular motion with a self-referenced visual environment. Results show that when users are placed under a visual-vestibular synchronised condition, their subjective miserable score of cybersickness decreased while their comfort level of the overall experience increased. This indicates that a motion-coupled system, if integrated seamlessly in VR, could mitigate cybersickness symptoms.     

A qualitative study of smartwatch usage and its usability

This study aims to explore usability issues of watch‐type wearable devices and to suggest guidelines for improved operation of smartwatches. To do so, we conducted a series of surveys, interviews, and task performance experiments. Thirty smartwatch users from ages 20 to 43 years were recruited. Users’ experiences of smartwatches were collected via a weeklong, online‐based diary study, which consisted of various tasks to be completed while smartwatches were in use. Our study assessed usability problems associated with those tasks, concurrent tasks conducted while interacting with smartwatches, pain points/discomfort that users had while interacting with their devices, and requirements/requests of the smartwatch users. During the week of tracking, participants were asked to complete the usability evaluation three times a day using usability principles we designed for the study: information display, control, learnability, interoperability, and preference. In addition, task performance tests were conducted for the tasks most frequently conducted on touch‐based displays: number entry, swiping, and scrolling. Specific usability issues of smartwatches were identified and summarized for each usability principle by triangulating survey, interview, and task performance evaluation results. Based on the insights from the results of the study, we conclude by suggesting guidelines for further enhancing users’ experience of future smartwatches.     

Multi-class classification of construction hazards via cognitive states assessment using wearable EEG

Improving workers’ safety and health is one of the most critical issues in the construction industry. Research attempts have been made to better identify construction hazards on a jobsite by analyzing workers’ physical responses (e.g., stride and balance) or physiological responses (e.g., brain waves and heart rate) collected from the wearable devices. Among them, electroencephalogram (EEG) holds unique potential since it reveals abnormal patterns immediately when a hazard is perceived and recognized. Unfortunately, the unproven capacity of EEG signals for multi-hazard classification is a primary barrier towards ubiquitous hazard identification in real-time on jobsites. This study correlates EEG signal patterns with construction hazard types and develops an EEG classifier based on the experiments conducted in an immersive virtual reality (VR) environment. Hazards of different types (e.g., fall and slip/trip) were simulated in a VR environment. EEG signals were collected from subjects who wore both wearable EEG and VR devices during the experimentation. Two types of EEG features (time-domain/frequency-domain features and cognitive features) were extracted for training and testing. A total of eighteen advanced machine learning algorithms were used to develop the EEG classifier. The initial results showed that the LightGBM classifier achieved 70.1% accuracy based on the cognitive feature set for the 7-class classification. To improve the performance, the input data was relabeled, and three strategies were designed and tested. As a result, the combined approach (two-step ensemble classification) achieved 82.3% accuracy. As such, this study not only demonstrates the feasibility of coupling wearable EEG, VR, and machine learning to differentiate jobsite hazards but also provides strategies to improve multi-class classification performance. The research results support ubiquitous hazard identification and thereby contribute to the safety of the construction workplace.     

Effects of Displays on Visually Controlled Task Performance in Three‐Dimensional Virtual Reality Environment

This study aims to evaluate three commercial virtual reality (VR) display devices on the market via a 3D Fitts's task. In addition, a symptom questionnaire was used to assess the severity of cybersickness symptoms induced by these displays. Ten participants performed repetitive pointing tasks over different conditions of varying display devices, movement directions, and indices of difficulty. On the basis of the results, the projection display obtained the best task performance with the lowest movement time and the highest throughput. It had the least symptoms among the three display devices. The HMD gave the worst results in all criteria. The 3D TV could be considered as good as the projection display in task performance but induced slight level of discomfort, fatigue, and eyestrain. These findings not only provided an initial understanding of differences between the 3D TV and the other two familiar display devices in human performance when interacting within a 3D VE but also pointed a direction to effectively improve future VR display technique.     

A virtual reality keyboard with realistic haptic feedback in a fully immersive virtual environment

This study presents a 3D virtual reality (VR) keyboard system with realistic haptic feedback. The system uses two five-fingered data gloves to track finger positions and postures, uses micro-speakers to create simulated vibrations, and uses a head-mounted display (HMD) for 3D display. When users press a virtual key in the VR environment, the system can provide realistic simulated key click haptic feedback to users. The results of this study show that the advantages of the haptic VR keyboard are that users can use it when wearing HMDs (users do not need to remove HMDs to use the VR keyboard), the haptic VR keyboard can pop-up display at any location in the VR environments (users do not need to go to a specific location to use an actual physical keyboard), and the haptic VR keyboard can be used to provide realistic key click haptic feedback (which other studies have shown enhances user performance). The results also show that the haptic VR keyboard system can be used to create complex vibrations that simulate measured vibrations from a real keyboard and enhance keyboard interaction in a fully immersive VR environment.     

What input errors do you experience? Typing and pointing errors of mobile Web users

Small devices such as personal digital assistants (PDAs) are widely used to access the World Wide Web (Web). However, accessing the Web from small devices is affected by poor interface bandwidth, such as small keyboards and limited pointing devices. There is little empirical work investigating the input difficulties caused by such insufficient facilities, however, anecdotal evidence suggests that there is a link between able-bodied users of the mobile Web and motor impaired users of the Web on desktop computers. This being the case we could transfer the solutions which already exists for motor impaired users into the mobile Web and vice versa. This paper presents a user study that investigates the input errors of mobile Web users in both typing and pointing. The study identifies six types of typing errors and three types of pointing errors shared between our two user domains. We find that mobile Web users often confuse the different characters located on the same key, press keys that are adjacent to the target key, and miss certain key presses. When using a stylus, they also click in the wrong places, slide the stylus during multiple clicks, and make errors when dragging. Our results confirm that despite using different input devices, mobile Web users share common problems with motor impaired desktop users; and we therefore surmise that it will be beneficial to transfer available solutions between these user domains in order to address their common problems.     

用于虚拟现实系统的眼动交互技术综述

眼动人机交互利用眼动特点可以增强用户的沉浸感和提高舒适度,在虚拟现实（VR）系统中融入眼动交互技术对VR系统的普及起到至关重要的作用,已成为近年来的研究热点。对VR眼动交互技术的原理和类别进行阐述,分析了将VR系统与眼动交互技术结合的优势,归纳了目前市面上主流VR头显设备及典型的应用场景。在对有关VR眼动追踪相关实验分析的基础上,总结了VR眼动的研究热点问题,包括微型化设备、屈光度矫正、优质内容的匮乏、晕屏与眼球图像失真、定位精度、近眼显示系统,并针对相关的热点问题展望相应的解决方案。     

Comparison of Gaze Cursor Input Methods for Virtual Reality Devices

Virtual reality (VR) devices have recently become popular; however, research on input methods for VR devices is lacking. The main input methods of current commercial devices can be classified into two categories: manual selection using a controller and gaze selection. This study aims to derive the optimal input method and timing for VR devices by analyzing the performance of these input methods. A study is conducted in which participants wear a VR headset and select an activated input button from a 3 × 3 array on a VR device with two button sizes and two input methods. The manual selection method exhibits a shorter task completion time but a greater error number compared to the gaze selection method. For the gaze selection method, the task completion time and target search time were shortest when the gaze timing was 1 s. Further, the button size was determined to be statistically significant only when the manual selection method was used. The results of this study can be used as a reference in future VR user experience and product design.     

Extending the desktop workplace by a portable virtual reality system

Users are increasingly recognizing the potential of virtual reality (VR) technology for applications such as data analysis, design review, product development, production planning, marketing, training, etc. The currently established workflow is to design and construct at a desktop system with CAD or modeling software, and visualize and evaluate the results at one or more VR centers equipped with CAVEs or Powerwalls.Discussions with users of VR installations have shown that there is a demand for smaller and more cost efficient VR installations. We have proposed the concept of a small VR system, PI-casso, based on user requirements, guidelines for office workplaces and some end-user tests which showed important limitations and the ergonomics problems of current VR installations. PI-casso is a compact, fully immersive VR system which complements the classic desktop workplace.In this paper we describe a set of user requirements and the results of the design in forming end-user tests, in addition to the concept and the technical specifications of the newly developed system. The first prototype of PI-casso was demonstrated at HCII 2003, where specialists from the human factors/ergonomics and the VR communities used our system and provided suggestions for improvement. This expert feedback was used to develop the improved versions described in this paper.     

Self-reported discomfort when using commercially targeted virtual reality equipment in discomfort distraction

Commercially targeted virtual reality (VR) equipment is gaining popularity and might be a viable tool for pain distraction. This experimental research aimed to discover whether active distraction techniques (such as commercially targeted VR and video games) result in reduced subjective discomfort relative to passive distraction techniques. The study examined a healthy adult population who experienced an experimentally induced discomfort task. Participants were 27 adults, 14 females and 13 males. Participants completed four tasks, a baseline measure of physical discomfort, video clip distraction (passive distraction), video game distraction (active distraction) and exploring a VR world using an Oculus Rift head-mounted display (active distraction). In all four test conditions, participants were asked to sit on a chair holding their non-dominant leg at a height of approximately 30 cm from the floor, up to a maximum of 5 min. Counterbalancing of task order was conducted to reduce effects of participant fatigue. The participants indicated significantly reduced self-reported discomfort in the active distraction tasks when compared to the passive distraction tasks. While the findings demonstrate the effectiveness of a commercially targeted VR technology in increasing pain tolerance, the relative benefits of this technology over non-immersive video games are not apparent.     

To twist,roll, stroke or poke? A study of input devices for menu navigation in the cockpit

Modern interfaces within the aircraft cockpit integrate many flight management system (FMS) functions into a single system. The success of a user's interaction with an interface depends upon the optimisation between the input device, tasks and environment within which the system is used. In this study, four input devices were evaluated using a range of Human Factors methods, in order to assess aspects of usability including task interaction times, error rates, workload, subjective usability and physical discomfort. The performance of the four input devices was compared using a holistic approach and the findings showed that no single input device produced consistently high performance scores across all of the variables evaluated. The touch screen produced the highest number of ‘best’ scores; however, discomfort ratings for this device were high, suggesting that it is not an ideal solution as both physical and cognitive aspects of performance must be accounted for in design.

Practitioner summary: This study evaluated four input devices for control of a screen-based flight management system. A holistic approach was used to evaluate both cognitive and physical performance. Performance varied across the dependent variables and between the devices; however, the touch screen produced the largest number of ‘best’ scores.     

A discomfort survey in a poultry-processing plant

The relationship of musculoskeletal pain and discomfort due to awkward work postures, forces, static loading and over-use is widely accepted as an indicator of poor job design. A discomfort survey was conducted in a poultry-processing plant to help to prioritize areas for ergonomics intervention and to determine whether regions of discomfort relate to types of task performed. The survey form was basic, to accommodate illiteracy, and was administered to 699 employees. Demographic data and job information were recorded. The employee rated job satisfaction and overall discomfort, shaded areas of discomfort on a body diagram and rated the intensity of the discomfort for each area. The jobs were coded into four mutually exclusive categories: hand tool, hand manipulation, material handling and mixed task. A discomfort index (DI) combined the number of shaded areas with intensity. Of the 65% who reported discomfort, the back had the highest mean maximum intensity followed by the arm, contrary to prevalence ranking of body regions. In the light of the findings, the benefit of rotation in a plant requiring major redesign is questioned. Results unexpectedly highlighted women who reported arm discomfort with more than one job, and who performed manual material-handling tasks, to have a significant discomfort problem, which indicates the breadth of ergonomics intervention required in the poultry environment. Surprisingly, no other effects of task were found. The survey provided useful indications of ergonomics issues in areas not identified by medical records.     

Ergonomics considerations in the design and use of single disc floor cleaning machines.

This study investigated ergonomics issues connected with the use of single-disc floor cleaning machines (buffers/polishers). Methods included interview/questionnaire surveys of users and other groups (maintenance personnel, purchasing managers, manufacturer representatives), along with video analysis. A notable proportion of users (56%) reported discomfort from machine use, mostly musculoskeletal in origin. Main locations were hand (39%), shoulder (19%), wrist (7%), lower back (7%) and arm (6%). Deficiencies were identified with the design and configuration of the handle/operating-switch. Problems were also found arising from the trailing power cable, along with manual handling implications due to machine size and weight. It is concluded there is scope to improve on current designs.     

Forget about ergonomics in chair design? Focus on aesthetics and comfort!

Chair users have difficulties distinguishing between chairs of different ergonomics quality. Many ergonomics features that are supposed to relieve discomfort in sitting are indistinguishable because they cannot be perceived. This is due to poor proprioceptive feedback from ligaments, joints and the spine. The joints are relatively insensitive to small changes in angle, and the spine cannot sense differences in pressure due to different body postures. Aesthetics features on the other hand, and features related to comfort and relaxation, are easier to perceive and differentiate. A study of ergonomics chairs verified that users could distinguish between parameters that relate to aesthetics and comfort, but had difficulty in distinguishing between ergonomics features. In the end aesthetics may be more important than ergonomics—at least to the customer who will be guided more by aesthetics than longer-term ergonomic factors.     

Multiple decoupled interaction: An interaction design approach for groupware interaction in co-located virtual environments

Interactive visualizations such as virtual environments and their associated input and interface techniques have traditionally focused on localized single-user interactions and have lacked co-present active collaboration mechanisms where two or more co-located users can share and actively cooperate and interact with the visual simulation. VR facilities such as CAVEs or PowerWalls, among many others, seem to promise such collaboration but due to the special requirements in terms of 3D input and output devices and the physical configuration and layout, they are generally designed to support an active controlling participant—the immersed user—and a passive viewing only audience. In this paper we explore the integration of different technologies, such as small handheld devices and wireless networks with VR/VEs in order to develop a technical and conceptual interaction approach that allows creation of a more ad hoc, interaction rich, multimodal and multi-device environment, where multiple users can access certain interactive capabilities of VE and support co-located collaboration.     

Human centred design of 3-D interaction devices to control virtual environments

It is commonly acknowledged that user needs should drive design, but often technical influences prevail. Currently, there are no standard interaction devices or interfaces used in 3-D environments, and there is a lack of specific best practice guidelines to develop these. This paper discusses the process of collecting feedback on prototype designs for VR/VE interaction devices from both expert users and non-expert users, and demonstrates how the information gained from human centred evaluation can be used to further the design process. Experiment 1 examined the usability of two magnetically tracked interaction devices with three different types of menus (Sphere, Linear and Fan). Quantitative and qualitative analysis was carried out on the results, and usability problems with the menus and devices are discussed. The findings from this experiment were translated into general design guidance, in addition to specific recommendations. A new device was designed on the basis of some of these recommendations and its usability was evaluated in Experiment 2. Feedback from participants in Experiment 2 demonstrated that the design recommendations emerging from Experiment 1 were successfully applied to develop a more usable and acceptable device.     

Forget about ergonomics in chair design? Focus on aesthetics and comfort!

Chair users have difficulties distinguishing between chairs of different ergonomics quality. Many ergonomics features that are supposed to relieve discomfort in sitting are indistinguishable because they cannot be perceived. This is due to poor proprioceptive feedback from ligaments, joints and the spine. The joints are relatively insensitive to small changes in angle, and the spine cannot sense differences in pressure due to different body postures. Aesthetics features on the other hand, and features related to comfort and relaxation, are easier to perceive and differentiate. A study of ergonomics chairs verified that users could distinguish between parameters that relate to aesthetics and comfort, but had difficulty in distinguishing between ergonomics features. In the end aesthetics may be more important than ergonomics--at least to the customer who will be guided more by aesthetics than longer-term ergonomic factors.     

Experimental research into human cognitive processing in an augmented reality environment for embedded training systems

Research into human factors issues associated with the use of augmented reality (AR) technology is very limited. Consequently, there is a need for formal human factors design guidelines to underpin the integration of AR into systems. The Defence Evaluation and Research Agency (DERA) Centre for Human Sciences (CHS) is evaluating the potential of AR for providing real-time training feedback in future advanced embedded training systems for the military. In order to understand the important human factors issues of augmented reality, DERA funded the Advanced VR Research Centre (AVRRC) at Loughborough University to investigate the cognitive ergonomics of this technology. An important aspect of this research is concerned with identifying any human information processing issues that may arise when information is presented via AR and overlaid upon one or more primary display surfaces such as a visual display unit (VDU). Two main issues are addressed in this research. First, the impact of AR on human information processing and second, subjective workload experienced when displaying information via the AR medium. The experiments reported in this paper assess issues of reaccommodation and reaction times to alarms on different display formats. They demonstrate also that AR performs as well as standard display formats.     

Using non-keyboard input devices: interviews with users in the workplace

A study of 45 non-keyboard input device (NKID) users was undertaken at nine organisations to investigate the extent, pattern and method of NKID usage, workstation configurations, postures adopted and musculoskeletal symptoms. A number of methods were used: work activity diaries, interviews, observations and postural assessments. A range of NKID were seen including the mouse, touchscreen, joystick, trackball, and tablet and pen; however, the mouse was the most commonly used device. Use of an input device varied from 2% to 100% of the working day. Workers undertook common tasks using a variety of methods (e.g. pull down menus, icons, device buttons). Users reported problems associated with the use of some devices, e.g. poor maintenance, lack of device responsiveness. Musculoskeletal pain and discomfort (e.g. stiffness and discomfort in the hands and wrist) was reported by 45% (n=19) of mouse users and 16% (n=5) of other NKID users. Workstation configurations varied and in some cases constrained the position of the input device, resulting in users having to work with the device at some distance away from the body. Despite the existence of regulations and guidance, this paper indicates that there are still many problems related to NKID use at computer workstations.

Relevance to industry

The reliance of many software applications on NKID (e.g. mouse, trackball, touchpad, joystick, touchscreen) necessitates the investigation of their use in the workplace. Whilst the performance aspects of NKID (e.g. speed) have been well researched, the possible implications for user health have received little attention in the UK.