59 research outputs found

    Designing virtual environments for brain injury rehabilitation

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    Virtual Reality (VR) has shown great potential in various training applications. In the field of cognitive rehabilitation it has been shown that VR technology can become a useful complement to conventional rehabilitation techniques (e.g. Rizzo et al. (2002), Brown et al. (2002) and Kizony et al. (2002)). An important part of a brain injury patient’s rehabilitation process is practicing instrumental activities of daily living (IADL), such as preparing meals, cleaning, shopping and using a telephone. A pilot study by LindĂ©n et al. (2000) came to the conclusion that activities like these can be practiced using desktop VR. The question addressed in this thesis is how a Virtual Environment (VE) should be designed to be a usable tool in brain injury rehabilitation. The thesis consists of three papers that describe three different studies that have been performed in order to further explore this area of research. Paper I describes the design of a practical VE application in the shape of a cash dispenser. A paper prototype was constructed which was first used to generate ideas from three occupational therapists. The prototype was then tested on six people with little or moderate computer knowledge and no experience of 3D computer simulations. The results from the evaluation were then used to implement a computer prototype with the VR development tool World Up. The computer prototype had automatic navigation, which meant that the position and orientation of the viewpoint, the user’s view into the VE, was controlled by the computer. The point-and-click method, which allows the user to move and manipulate objects with single mouse clicks, was used for interaction with objects. The computer prototype was then tested on five brain injury patients. The results of this evaluation are not included in paper I but are described in the thesis summary. Overall, all five subjects learned to handle the computer prototype sufficiently well. However, the interaction with objects posed some problems for them. For example, they initially tried to move the bankcard with drag-and-drop instead of point-and-click. Three subjects also pointed out that some parts of the VE, for example the display and the keypad, were unclear. All five subjects showed a positive attitude to the virtual cash dispenser The aim of paper II was to find a usable navigation input device for people with no experience of 3D computer graphics. After an initial discussion about various input devices it was decided that a Microsoft Sidewinder joystick and an IntelliKeys keyboard, both programmed with two and three degrees of freedom (DOF), should be compared in an experiment. Sixty able-bodied people with no experience of 3D computer graphics were divided into four groups. Each group was to perform a navigation task in a VE consisting of a kitchen and a corridor using one of the four input devices. The navigation task was designed to evaluate both fine adjustments of the viewpoint (maneuvering task) and transportation of the viewpoint from one location to another (search task). Each subject performed the task five times in a row and then answered a questionnaire consisting of five questions. Data logging and video recording were used to collect data. The study showed that both keyboard and joystick have their advantages and disadvantages. The keyboard seemed to be easier to control than the joystick for the maneuvering task. The keyboard was slightly easier to control also for the search task but was much slower than the joystick, which might make it an inconvenient input device for VEs that only involve search navigation. No significant difference could be found between two and three DOFs for the maneuvering task, but the 3rd DOF (sideways movement) seemed to facilitate the subjects’ navigation in some situations. Two DOFs was found to be slightly easier to control than three DOFs for the search task. The study described in paper III aimed at 1) evaluating a method for interaction with objects in VEs on people with no 3D computer graphics experience, and 2) finding a sufficiently usable input device for this purpose. After an initial discussion of possible methods for interaction with objects and various input devices, an experiment was conducted with 20 able-bodied people with no experience of 3D computer graphics. Our experiences of point-and-click from paper I and the pilot study (LindĂ©n et al., 2000) made us think that maybe people have a more inherent understanding for drag-and-drop. Also, we had discussed using a virtual hand for carrying objects to simplify object movement. We therefore wanted to evaluate the following method for interaction with objects: 1) A virtual hand was used for carrying objects, 2) drag-and-drop was used for moving objects, 3) a single click was used for activating objects, and 4) objects were given a proper orientation automatically. Ten subjects used a regular desktop mouse and the other ten a touch screen to perform four interaction tasks in a kitchen VE five times in a row. Video recording was used to document the trial and the interview that was conducted afterwards. Broadly, the method for interaction with objects worked well. The majority of the subjects used the virtual hand for carrying objects. However, the fact that some subjects needed information before they started to use it indicates that its visibility and affordance needs to be improved. Opening and closing cupboard doors caused some problems, especially for the subjects in the touch screen group who tried to open them with drag-and-drop in a manner that resembled reality. No large difference in performance, except from the problem with the cupboard doors, could be seen between the mouse group and the touch screen group. The three studies described in this thesis is a step closer towards understanding how a VE should be designed in order to be a usable tool for people with brain injury. In particular, knowledge on how to make it as easy as possible for the user to navigate the viewpoint and interact with objects has been achieved. The work has also provided a deeper understanding on what effects the choice of input device has on the usability of a VE

    Feasibility Study of Ubiquitous Interaction Concepts

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    AbstractThere are all sorts of consumer electronics in a home environment. Using “apps” to interact with each device is neither feasible nor practical in an ubicomp future. Prototyping and evaluating interaction concepts for this future is a challenge. This paper proposes four concepts for device discovery and device interaction implemented in a virtual environment. The interaction concepts were compared in a controlled experiment for evaluation and comparison.Some statistically significant differences and subjective preferences could be observed in the quantitative and qualitative data respectively.Overall, the results indicate that the proposed interaction concepts were found natural and easy to use

    Exhaustion-related changes in cardiovascular and cortisol reactivity to acute psychosocial stress.

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    Prior findings indicate that individuals scoring high on vital exhaustion show a dysfunctional stress response (DSR), that is, reduced cortisol reactivity and habituation to psychosocial stressors. The main aim of the present study was to examine whether a DSR may be a vulnerability factor in exhaustion disorder (ED). We examined whether a DSR is present during the early stages of ED, and still is present after recovery. Three groups were studied: 1. Former ED patients (n = 14); 2. persons who during the past 6 month had experienced stress at work and had a Shirom-Melamed Burnout Questionnaire (SMBQ) score over 3.75, considered to indicate a pre-stage of ED (n = 17); 3. persons who had not experienced stress at work during the past 6 months and had a SMBQ score below 2.75 (n = 20). The participants were exposed twice to a virtual version of the Trier Social Stress Test (V-TSST), during which salivary cortisol samples were collected. In addition, high frequency heart rate variability (HF-HRV), heart rate (HR), t-wave amplitude (TWA), and alpha-amylase were assessed to examine stress reactivity and habituation in the autonomic nervous system (ANS). The initial analyses showed dear hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS) activations in both V-TSST sessions, together with habituation of cortisol and heart rate in the second session, but without any significant group differences. However, the former ED patients showed considerable variation in self-reported signs of exhaustion (SMBQ). This led us to assign former ED patients with lower ratings into the low SMBQ group (LOWS) and those with higher ratings to the high SMBQ group (HIGHS). When repeating the analyses a different picture emerged; the HIGHS showed a lower cortisol response to the V-TSST than did the LOWS. Both groups' cortisol response habituated to the second V-TSST session. The ANS responses did not differ between the two groups. Thus, persons in a pre-stage of ED and unrecovered former ED patients showed signs of DSR, in contrast to healthy controls and recovered former ED patients. The results may be interpreted as indicating that DSR in the HPA axis is present early on in the stress process, but subsides after successful recovery. (C) 2015 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

    Analysis of Visualisation and Interaction Tools Authors

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    This document provides an in-depth analysis of visualization and interaction tools employed in the context of Virtual Museum. This analysis is required to identify and design the tools and the different components that will be part of the Common Implementation Framework (CIF). The CIF will be the base of the web-based services and tools to support the development of Virtual Museums with particular attention to online Virtual Museum.The main goal is to provide to the stakeholders and developers an useful platform to support and help them in the development of their projects, despite the nature of the project itself. The design of the Common Implementation Framework (CIF) is based on an analysis of the typical workflow ofthe V-MUST partners and their perceived limitations of current technologies. This document is based also on the results of the V-MUST technical questionnaire (presented in the Deliverable 4.1). Based on these two source of information, we have selected some important tools (mainly visualization tools) and services and we elaborate some first guidelines and ideas for the design and development of the CIF, that shall provide a technological foundation for the V-MUST Platform, together with the V-MUST repository/repositories and the additional services defined in the WP4. Two state of the art reports, one about user interface design and another one about visualization technologies have been also provided in this document

    Virtual environments as a tool for people with acquired brain injury

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    People with acquired brain injury (ABI) often have problems leading an independent life due to impaired cognitive abilities. One way to address this is to let the patients practise activities of daily living as part of their rehabilitation process. However, some everyday activities can be difficult, inconvenient or risky to practise. The demands of the environment can also have an impact on the independence of an individual with ABI. Today, the involvement of people with ABI in the design of public space in minimal. Scarcely any regard is taken to this population when planning a new public transport system, for example. Accordingly, there is a need for development of methodology that can facilitate life for people with ABI. Virtual reality (VR) technology has shown great potential for various applications such as training, learning, visualisation and design. The objectives of the research presented in this doctoral thesis were to: 1) investigate how VR training can be used as a rehabilitation tool by people with ABI, and 2) explore if and how VR can be used to elicit knowledge about public transport accessibility for people with ABI. The first research objective was investigated in four studies in which 60 able-bodied people with little or no experience of 3D computer graphics and 12 people with traumatic brain injury (TBI) participated. Case study methodology was applied, using observations, interviews and think-aloud protocols to collect data. One of the studies also used quantitative data and statistics. So called desktop VR (i.e. a standard monitor and regular input devices) was used. Three virtual environments were used: a kitchen, a cash dispenser and a hospital environment. In general, the results of the four studies suggest that VR has great potential as a training tool for people with ABI. However, the results also highlighted the importance of an optimised interface between the user and the VR system; seemingly small usability problems can create significant difficulties for a person with ABI. In the first study, a comparison was carried out between a joystick and a special keyboard for navigation in virtual training environments. There were two versions of each input device: one with two degrees of freedom and one with three. The keyboard was found to be more suitable for navigation tasks in which the user wants to give the viewpoint a more advantageous position and orientation for carrying out a specific task. No statistically significant differences between two and three degrees of freedom could be found. Nevertheless, the third degree of freedom, which made it possible to also move sideways, seemed to facilitate the navigation in some situations. The aim of the second study was to evaluate a method for interaction with virtual objects and to compare mouse and touch screen as input device for this purpose. The data showed no difference in performance between the mouse and touch screen subjects. Several touch screen subjects tended to imitate the way things are done in real life, however. This suggests that the touch screen is a more suitable input device in this context since the virtual activity resembles the real world activity. The third study investigated if and how five subjects with ABI could transfer route knowledge from a virtual hospital environment to the real world. They managed to walk a route they had only practised in a virtual environment, which suggests that VR-based route training can be a feasible complement to conventional route training. The aim of the fourth study was to develop and evaluate a virtual cash dispenser that can be used as a training tool by people with ABI. Seven people with ABI practised withdrawing money from the virtual cash dispenser. In general, they learned how to use the virtual cash dispenser. However, some usability problems, mainly related to interaction with virtual objects were noted. Another result, which could also be observed in the second study, was that unclear or non-existing feedback from the VR application was the cause of several of these problems. The second research objective was addressed in two studies in which eleven people with ABI and four occupational therapists participated. Once again, case study methodology was used. Data was collected through observations, think-aloud protocols and interviews. Both studies used a virtual environment in which a complete bus trip could be performed. The first study evaluated a suggested VR methodology for enabling people with cognitive disabilities to communicate their knowledge and experiences of public transport systems. The users interacted with the VR system by verbally describing their actions to the person controlling the VR system and/or pointing with a laser pointer while seated in front of three screens on which the virtual environment was projected. Seven people with stroke were filmed as they made a virtual bus trip and were then asked to think aloud about their experience while watching the video material. Despite some initial difficulties, the subjects managed to communicate their intentions, some by combining verbalisations and pointing with the laser pointer in a very efficient manner. They were engaged in the virtual bus trip and made comments on the experience, including comments on emotional aspects. Interestingly, the subjects’ verbal descriptions of what they wanted to do revealed in part aspects of how they reasoned when taking the bus trip. The results suggested that the VR methodology can be a feasible tool for people with cognitive disabilities but also revealed several issues in need of improvement. The second study investigated if and how the VR methodology can be used to elicit knowledge from occupational therapists and people with ABI about public transport accessibility for the latter population. Four people with ABI made a virtual bus trip and afterwards were asked to think aloud about their experience while watching the video material from the bus trip. Four occupational therapists with experience of working with people with ABI performed the virtual bus trip while at the same time thinking aloud about public transport accessibility for people with ABI. Afterwards they watched the video material from the virtual bus trip of one of the subjects with ABI while once again thinking aloud about public transport accessibility. In general, both subject groups handled the VR methodology. The most relevant knowledge from the subjects with ABI was related to concrete accessibility problems, emotional aspects and strategies. The direct observations of the ABI subjects making the virtual bus trip led to the identification of some problems but revealed very little about what caused them. Instead, the cause of the problems came to light through the ABI subjects’ verbalisations, which demonstrates the importance of not only making observations but also paying attention to the participant’s subjective experience. The most relevant knowledge from the occupational therapists concerned the concrete accessibility problems and suggested solutions. Both think aloud sessions elicited unique knowledge from the occupational therapists and should therefore be part of the VR methodology in order to cover as many aspects as possible of public transport accessibility for people with ABI. Overall, the results suggested that the concept of first carrying out actions in a virtual environment and then reflecting over these actions seems to be a very good way of eliciting knowledge about public transport accessibility for people with ABI. The elicited knowledge from people with ABI and occupational therapists seems to illuminate, in part, different aspects of public transport accessibility and hence is complementary
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