Chronic low back pain (CLBP) is a disabling condition that significantly limits overall functioning and quality of life. Although exercise therapy (ET) is a widely recommended treatment, patient adherence and motivation remain low, especially in home-based rehabilitation. This study presents the design, development, and initial evaluation of a gamified cycling exercise with high intensity interval training (HIIT) tailored for persons with CLBP. The game integrates cardiorespiratory interval training into a gamified environment to create a motivating and personalised exercise experience. Based on a formative expert evaluation, we conclude that the game concept provides a natural and motivating setting for a high-intensity cycling exercise. Some recommended design improvements to enhance the natural alignment of the game and the HIIT training have been identified. Further exploration of the game concept with patients is needed to determine its feasibility and effectiveness. The results of the current study will shape the design and development of digital health interventions that support motivating and enjoyable rehabilitation in and outside clinical settings.

After a cardiac event, secondary prevention is recommended to foster recovery and reduce the risk of recurrent events. European guidelines and EAPC position statements on prevention of cardiovascular diseases recommend a holistic approach that actively engages patients by using shared decision making (SDM). It has been demonstrated that telerehabilitation can be a feasible and effective add-on or alternative compared to conventional in-hospital secondary prevention. However, till date, there is no eHealth solution that offers a holistic approach for secondary prevention that includes SDM. In this paper, we present the CoroPrevention-SDM approach, a technology-supported shared decision making approach for a comprehensive secondary prevention program for cardiac patients. The CoroPrevention Tool Suite consists of three applications that support patients and caregivers in following this approach: 1) a caregiver dashboard that includes decision support systems and supports SDM, 2) a patient mobile application that supports patients in making behaviour changes in their daily life, and 3) an extended ePRO application that collects patient reported outcomes and patient preferences. In a formative usability study, we assessed patients' and caregivers' opinion about our approach. The study indicated that both are willing to use our proposed approach to collaboratively set behavioural goals during SDM encounters.

People with Multiple Sclerosis (pwMS) suffer from a diverse set of symptoms such as fatigue, pain, depression, and decline in motor and cognitive function. It has been proven that physical activity has a positive effect on most of these symptoms. However, many pwMS lead sedentary lives, and do not meet the guidelines for physical activity. We propose WalkWithMe, a mobile application that supports pwMS in walking. WalkWithMe coaches pwMS in achieving a personal goal over a period of 10 weeks. We conducted a workshop with pwMS and brainstorm sessions with experts in rehabilitation to define the design choices of WalkWithMe. We examined the impact of WalkWithMe in a 10-week field study with 13 pwMS. The study revealed insights in walking habits, and positive trends in walking capacity. In this paper, we present the design aspects of WalkWithMe, findings of our 10-week evaluation, and resulting insights on goal setting for pwMS.

Abstract Physical exercise training and medication compliance are primary components of cardiac rehabilitation. When rehabilitating independently at home, patients often fail to comply with their prescribed medication and find it challenging to interpret exercise targets or be aware of the expected efforts. Our work aims to assist cardiac patients in understanding their condition better, promoting medication adherence and motivating them to achieve their exercise targets in a tele-rehabilitation setting. We introduce a patient-centric intelligible visualization approach to present prescribed medication and exercise targets to patients. We assessed efficacy of intelligible visualizations on patients’ comprehension in two lab studies. We evaluated the impact on patient motivation and health outcomes in field studies. Patients were able to adhere to medication prescriptions, manage their physical exercises, monitor their progress and gained better self-awareness on how they achieved their rehabilitation targets. Patients confirmed that the intelligible visualizations motivated them to achieve their targets better. We observed an improvement in overall physical activity levels and health outcomes of patients. Research Highlights Presents challenges currently faced in cardiac tele-rehabilitation. Demonstrates how intelligibility was applied to two core aspects of cardiac rehabilitation- promoting medication adherence and physical exercise training. Lab., field and clinical studies to demonstrate efficacy of intelligible visualization, impact on patient motivation and resultant health outcomes. Reflection on how similar HCI approaches could be leveraged for technology-supported management of critical health conditions such as cardiac diseases.

Translation environments offer various translation aids to support professional translators. However, translation aids typically provide only limited justification for the translation suggestions they propose. In this paper we present Intellingo, a translation environment that explores intelligibility for translation aids, to enable more sensible usage of translation suggestions. We performed a comparative study between an intelligible version and a non-intelligible version of Intellingo. The results show that although adding intelligibility does not necessarily result in significant changes to the user experience, translators can better assess translation suggestions without a negative impact on their performance. Intelligibility is preferred by translators when the additional information it conveys benefits the translation process and when this information is not part of the translator's readily available knowledge.

We present the highlights of the now finished 4-year SCATE project. It was completed in February 2018 and funded by the Flemish Government IWT-SBO, project No. 130041.1

Keeping track of design processes is a cumbersome task due to the apparently unconstrained and unstructured nature of creative work. Traceability is fundamental to revisit and reflect on the design narratives that describe artefact evolution. In this paper, we aim to identify what characteristics are necessary to facilitate traceability of creative design processes. For this end, we use a functional prototype to connect artefacts, design rationale, and decisions in a shared workspace. We evaluated this prototype for 15 weeks with six pairs of students engaged in a user-centered design project. Our findings show that having a lean repository of artefacts annotated with design rationale can facilitate tracking progress in different phases of the process. We found that creating a record of the participants' design work is useful to reflect on and for team agreement, ensure consistency of evolving artefacts, and help in planning future steps in the design project.

We present Handly, an integrated upper-limb rehabilitation system for persons with a neurological disorder. Handly consists of tangibles for training four hand tasks with specific functional handgrips and a motivational game. These persons need intensive personalized therapy in order to sustain or enhance their abilities and aptitude in daily activities. Conventional approaches require intense support by a therapist or usage of expensive robots, both of which are not a sustainable model of training. Handly combines tangibles specifically designed for repetitive task-oriented motor skill training of typical daily activities with serious gaming, thus offering a comprehensive approach. A feedback mechanism guides the user and an accessible game environment stimulates individual training. We performed an initial evaluation of Handly with eight persons with Multiple Sclerosis. We show that a tangible-virtual environment for intensive upper-limb rehabilitation is feasible and that this approach is highly appreciated by the patients.

Persons that suffered from a cardiac disease are often recommended to integrate a sufficient level of physical exercise in their daily life. Initially, cardiac rehabilitation takes place in a closely monitored setting in a hospital or a rehabilitation center. Sustaining the effort once the patient has left the ambulatory, supervised environment is a challenge, and drop-out rates are high. Emerging approaches such as telemonitoring and telerehabilitation have been proven to show the potential to support the cardiac patient in adhering to the advised physical exercise. However, most telerehabilitation solutions only support a limited range of physical exercise, such as step-counting during walking. We propose BoB (Back on Bike), a mobile application that guides cardiac patients while cycling. Design choices are explained according to three pillars: ease of use, reduce fear, and direct and indirect motivation. In this paper, we report the results from a field study with cardiac patients.

Human-Robot Collaboration is increasingly considered in manufacturing to better combine the strengths of humans and robots. Establishing this human-robot collaboration may require multi-modal interaction; input to and output from the robot can both use multiple channels in sequence or in parallel. Designing effective interaction requires the expertise from different domains, possibly originating from people with different backgrounds. In our work we explore how composite events — hierarchical composition of events — can be used in a way that eases the communication within a multi-disciplinary team. In this paper, we present how the concept of composite events can be used to create different layers of abstraction that can be used to ease prototyping and discussion of human-robot collaboration with stakeholders through a supporting tool called Hasselt UIMS. At the lower level(s) of abstraction, the composite events can be mapped to the message-based communication as implemented in the Robotic Operating System (ROS), which is used to program collaborative robots, such as the Baxter robot from Rethink Robotics.

The creation of prototypes and their iterative adaptation are important stages in the time-consuming development process of a multimodal system. This reality has brought about the appearance of many specialized toolkits intended for facilitating the prototyping of multimodal systems. Using these toolkits, some functionalities of the intended prototype can be specified by means of a visual language instead of programming code. This article reports on a comparative study of a representative set of graphical toolkits for rapid prototyping of multimodal systems. It presents a set of criteria to identify the scope of a toolkit. According to their scopes, toolkits can be clustered into three classes called flow-based, state-based and token-based. Toolkits within each class do not only offer similar benefits to their users, but also exhibit resemblance in their underlying visual languages.

The misalignment between the timeframe of systems and that of their users can cause problems, especially when the system relies on implicit interaction. It makes it hard for users to understand what is happening and leaves them little chance to intervene. This paper introduces the design concept of slow-motion feedback, which can help to address this issue. A definition is provided, together with an overview of existing applications of this technique.

During remote video-mediated assistance, instructors often guide workers through problems and instruct them to perform unfamiliar or complex operations. However, the workers' performance might deteriorate due to stress. We argue that informing biofeedback to the instructor, can improve communication and lead to lower stress. This paper presents a thorough investigation on mental workload and stress perceived by twenty participants, paired up in an instructor-worker scenario, performing remote video-mediated tasks. The interface conditions differ in task, facial and biofeedback communication. Two self-report measures are used to assess mental workload and stress. Results show that pairs reported lower mental workload and stress when instructors are using the biofeedback as compared to using interfaces with facial view. Significant correlations were found on task performance with reducing stress (i.e. increased task engagement and decreased worry) for instructors and declining mental workload (i.e. increased performance) for workers. Our findings provide insights to advance video-mediated interfaces for remote collaborative work.

We present ReHoblet; a physical rehabilitation game on tablets, designed to be used in a residential setting. ReHoblet trains two gross motor movements of the upper limbs by lifting (up-down) and transporting (left-right) the tablet to control a simple platform game. By using its accelerometers and gyroscope, the tablet is capable of detecting movements made by the user and steer the interaction based on this data. A formative evaluation with five Multiple Sclerosis (MS) patients and their therapists showed high appreciation for ReHoblet. Patients stated they liked ReHoblet not only to improve their physical abilities, but to train on performing technology-related tasks. Based on the results, we reflect on tablet-based games in home-based rehabilitation.

Persons with a neurological disorder are confronted with significantly reduced physical abilities during their daily activities. Physiotherapy, for these patients mainly provided in rehabilitation centres, utilizes tangible, real-world objects in training for the upper limbs. Only by intensely and frequently exercising, patients have a chance to sustain or enhance their functional performance. Our research explores pervasive technologies and tangible objects to provide motivating, technology-supported training systems in a residential environment for independent use by these patients. In this paper, we describe our pervasive training system 'PhysiCube', consisting of prototypes 'LiftACube' and 'ReachACube'. PhysiCube takes advantage of tangible interactions and games to provide motivating physical training for the upper limbs. An evaluation with therapists showed great appreciation for our prototypes. Reflections on the technical setup and use of tangible interaction for these pervasive rehabilitation systems in a residential setting are elaborated upon.

Modern knowledge work consists of both individual and highly collaborative activities that are typically composed of a number of configuration, coordination and articulation processes. The desktop interface today, however, provides very little support for these processes and rather forces knowledge workers to adapt to the technology. We introduce co-Activity Manager, an activity-centric desktop system that (i) provides tools for ad hoc dynamic configuration of a desktop working context, (ii) supports both explicit and implicit articulation of ongoing work through a built-in collaboration manager and (iii) provides the means to coordinate and share working context with other users and devices. In this paper, we discuss the activity theory informed design of co-Activity Manager and report on a 14 day field deployment in a multi-disciplinary software development team. The study showed that the activity-centric workspace supports different individual and collaborative work configuration practices and that activity-centric collaboration is a two-phase process consisting of an activity sharing and per-activity coordination phase.

Feedback and affordances are two of the most well-known principles in interaction design. Unfortunately, the related and equally important notion of feedforward has not been given as much consideration. Nevertheless, feedforward is a powerful design principle for bridging Norman's Gulf of Execution. We reframe feedforward by disambiguating it from related design principles such as feedback and perceived affordances, and identify new classes of feedforward. In addition, we present a reference framework that provides a means for designers to explore and recognize different opportunities for feedforward.

Intelligent User Interfaces can benefit from having knowledge on the user's emotion. However, current implementations to detect affective states, are often constraining the user's freedom of movement by instrumenting her with sensors. This prevents affective computing from being deployed in naturalistic and ubiquitous computing contexts. In this paper, we present a novel system called mASqUE, which uses a set of association rules to infer someone's affective state from their body postures. This is done without any user instrumentation and using off-the-shelf and non-expensive commodity hardware: a depth camera tracks the body posture of the users and their postures are also used as an indicator of their openness. By combining the posture information with physiological sensors measurements we were able to mine a set of association rules relating postures to affective states. We demonstrate the possibility of inferring affective states from body postures in ubiquitous computing environments and our study also provides insights how this opens up new possibilities for IUI to access the affective states of users from body postures in a nonintrusive way.

Activity-Based Computing (ABC) has been proposed as an organisational structure for local desktop management and knowledge work. Knowledge work, however, typically occurs in partially overlapping subgroups and involves the use of multiple devices. We introduce co-Activity Manager, an ABC approach that (i) supports activity sharing for multiple collaborative contexts, (ii) includes collaborative tools into the activity abstraction and (iii) supports multiple devices by seamlessly integrated cloud support for documents and activity storage. Our 14 day field deployment in a multidisciplinary software development team showed that activity sharing is used as a starting point for long-term collaboration while integrated communication tools and cloud support are used extensively during the collaborative activities. The study also showed that activities are used in different ways ranging from project descriptions to to-do lists, thereby confirming that a document-driven activity roaming model seems to be a good match for collaborative knowledge work

Interactive surfaces have great potential for co-located collaboration because of their ability to track multiple inputs simultaneously. However, the multi-user experience on these devices could be enriched significantly if touch points could be associated with a particular user. Existing approaches to user identification are intrusive, require users to stay in a fixed position, or suffer from poor accuracy. We present a non-intrusive, high-accuracy technique for mapping touches to their corresponding user in a collaborative environment. By mounting a high-resolution camera above the interactive surface, we are able to identify touches reliably without any extra instrumentation, and users are able to move around the surface at will. Our technique, which leverages the back of users' hands as identifiers, supports walk-up-and-use situations in which multiple people interact on a shared surface.

Informing caregivers by providing them with contextual medical information can significantly improve the quality of patient care activities. However, information flow in hospitals is still tied to traditional manual or digitised lengthy patient record files that are often not accessible while caregivers are attending to patients. Leveraging the proliferation of pervasive awareness technologies (sensors, actuators and mobile displays), recent studies have explored this information presentation aspect borrowing theories from context-aware computing, i.e., presenting subtle information contextually to support the activity at hand. However, the understanding of the information space (i.e., what information should be presented) is still fairly abstruse, which inhibits the deployment of such real-time activity support systems. To this end, this paper first presents situated glyphs, a graphical entity to encode situation specific information, and then presents our findings from an in-situ qualitative study addressing the information space tailored to such glyphs. Applying technology probes using situated glyphs and different glyph display form factors, the study aimed at uncovering the information space pertained to both primary and secondary medical care. Our analysis has resulted in a large set of information types as well as given us deeper insight on the principles for designing future situated glyphs. We report our findings in this paper that we expect would provide a solid foundation for designing future assistive systems to support patient care activities.

When creating applications that should be available on multiple computing platforms, designers have to cope with different design tools and user interface toolkits. Incompatibilities between these design tools and toolkits make it hard to keep multi-device user interfaces consistent. This paper presents Jelly, a flexible design environment that can target a broad set of computing devices and toolkits. Jelly enables designers to copy parts of a user interface from one device to another and to maintain the different user interfaces in concert using linked editing. Our approach lowers the burden of designing multi-device user interfaces by eliminating the need to switch between different design tools and by providing tool support for keeping the user interfaces consistent across different platforms and toolkits.

Bringing together heterogeneous computing devices and appliances gives rise to a spontaneous environment where resources exchange messages, such as a mobile phone telling the car's stereo to mute. We also witness computer-augmented resources become physically simpler to use (e. g. less buttons) but become more complex to handle in their digital dimension (e. g. overloaded user interfaces). As a consequence, the behavior of the pervasive applications leveraging these resources gets even more complex to understand and configure. This demands for tools that help developers and end-users inspect and manipulate the current state of the pervasive computing environment during execution time. We present models and tools that support the development and deployment of applications that can be observed at runtime, by means of the messages they exchange, the properties they manipulate and the rules they define.

Pervasive applications are typically realized through ad-hoc service and user interface compositions. While many tools focus on the development of pervasive services by masking the complex technical side of a pervasive computing environment, the deployment of an application as a whole -- i.e. a set of services and user interfaces -- is often forgotten. We present an alternative design strategy and tool for pervasive applications in which pervasiveness is not considered a handicap, but rather as a situation that draws extra attention to the deployment of applications. By crafting pervasive applications and their services as independent context consumers and producers, we illustrate how the behaviour of a pervasive application deployed using our approach can be observed while it executes.

Users often become frustrated when they are unable to understand and control a pervasive computing environment. Previous studies have shown that allowing users to pose why and why not questions about context-aware applications resulted in better understanding and stronger feelings of trust. Although why and why not questions have been used before to aid in debugging and to clarify graphical user interfaces, it is currently not clear how they can be integrated into pervasive computing systems. We explain in detail how we have extended an existing pervasive computing framework with support for why and why not questions. This resulted in PervasiveCrystal, a system for asking and answering why and why not questions in pervasive computing environments.

Efficient discovery of nearby devices and services is one of the preconditions to obtain a usable pervasive environment. Typical user interfaces in these environments hide the heterogeneity of the environment for end-users which often makes it hard to perceive the provided functionality. We present Pervasive Maps, an approach and tool that allows to create an intuitive user interface for exploring and controlling the environment. Pervasive Maps offers user-oriented views on the user's environment based on pictures of this environment. We show how users can model, explore and finally interact with complex pervasive environments using Pervasive Maps.

Multi-device user interface design mostly implies creating suitable interface for each targeted device, using a diverse set of design tools and toolkits. This is a time consuming activity, concerning a lot of repetitive design actions without support for reusing this effort in later designs. In this paper, we propose D-Macs: a design tool that allows designers to record their design actions across devices, to share these actions with other designers and to replay their own design actions and those of others. D-Macs lowers the burden in multi-device user interface design and can reduce the necessity for manually repeating design actions.

In current mobile user interface design tools, it is time consuming to export a design to the target device. This makes it hard for designers to iterate over the user interfaces they are creating. We propose Gummy-live, a GUI builder for mobile devices allowing designers to test and observe immediately on the target device each step they take in the GUI builder. This way, designers are stimulated to iteratively test and refine user interface prototypes in order to take the target device characteristics into account.

Designers still often create a specific user interface for every target platform they wish to support, which is time-consuming and error-prone. The need for a multi-platform user interface design approach that designers feel comfortable with increases as people expect their applications and data to go where they go. We present Gummy, a multi-platform graphical user interface builder that can generate an initial design for a new platform by adapting and combining features of existing user interfaces created for the same application. Our approach makes it easy to target new platforms and keep all user interfaces consistent without requiring designers to considerably change their work practice.

Despite of decades of research, creating intuitive and easy to learn interfaces for 3D virtual environments (VE) is still not obvious, requiring VE specialists to define, implement and evaluate solutions in an iterative way, often using low-level programming code. Moreover, quite frequently the interaction with the virtual environment may also vary dependent on the context in which it is applied, such as the available hardware setup, user experience, or the pose of the user (e.g. sitting or standing). Lacking other tools, the context-awareness of an application is usually implemented in an ad-hoc manner, using low-level programming, as well. This may result in code that is difficult and expensive to maintain. One possible approach to facilitate the process of creating these highly interactive user interfaces is by adopting a model-based user interface design. This lifts the creation of a user interface to a higher level allowing the designer to reason more in terms of high-level concepts, rather than writing programming code. In this paper, we adopt a model-based user interface design (MBUID) process for the creation of VEs, and explain how a context system using an Event-Condition-Action paradigm is added. We illustrate our approach by means of a case study.

This paper presents how ad-hoc co-located collaborations can be supported with an arbitrary number of users that only have acces to small-size mobile displays. Our approach is based on tracking of these personal displays that share the same information space. All displays involved in the collaboration act as autonomous windows on a set of data items (the information space) positioned on a shared virtual canvas. Data items are identified by their three-dimensional location in physical space and can be manipulated through the displays that serve as windows on the shared canvas. Each display is tracked in physical space and is aware of its own location. Since different mobile displays can access and manipulate the same information space, a distributed locking mechanism makes sure the data stays consistent during simultaneous access of data in this information space.

This paper presents a modular runtime architecture supporting our model-based user interface design approach for designing context-aware, distributable user interfaces for ambient intelligent environments.

In this paper we show how an interactive system can be distributed among several peer devices. By taking advantage of the current trend towards ambient intelligent environments, we can make use of a combination of computing resources in the surrounding of the user to function as one logical interactive system; an interaction space. Our approach relies on the fact that nowadays most computing resources are network enabled and publish their device profile using some special purpose protocol. For this reason, federations of devices that support the tasks of the user can be composed automatically according to the requirements of these tasks. This distribution of the user interface over a federation of devices can be local or nonlocal. It raises the opportunity for supporting collaborative tasks with the same user interface with little or no extra effort from the user interface designer. Future tools supporting the design, creation and deployment of distributed interactive systems using device federations should maintain usability and usefulness of a dynamic distributed system. We use two different metrics to cope with these problems: interface completeness and interface continuity.

The usage of computing systems has evolved dramatically over the last years. Starting from a low level procedural usage, in which a process for executing one or several tasks is carried out, computers now tend to be used in a problem oriented way. Future computer usage will be more centered around particular services, and will not be focused on platforms or applications. These services should be independent of the technology used to interact with them. In this paper an approach will be presented which provides a uniform interface to such services, without any dependence on modality, platform or programming language. Through the usage of general user interface descriptions, presented in XML, and converted using XSLT, a uniform framework is presented for runtime migration of user interfaces. As a consequence, future services will become easily extensible for all kinds of devices and modalities. Special attention goes out to a component-based software development approach. Services represented by and grouped in components can offer a special interface for modal- and device-independent rendering. Components become responsible for describing their own possibilities and constraints for interacting. An implementation serving as a proof of concept, a runtime conversion of a joystick in a 3D virtual environment into a 2D dialog-based user interface, is developed.

Virtual environments and other applications of computer-generated scenes are emerging. This increases the demand for tools for efficient creation of the virtual worlds and interaction with the components in the virtual world. Introduction of immersiveness in the modeling process seems promising, but a number of issues related to immersive modeling still have to be investigated. The authors present a framework for an immersive modeling system with a hybrid 2D/3D user interface. The designer is immersed in the design space, which improves his awareness of the design objects under consideration. 2D and 3D human-computer interaction techniques are combined in the user interface to improve the efficiency of the modeler. While 3D interaction is natural for a number of design tasks, 2D interaction is particularly helpful for interaction with menus and dialog boxes, for precise manipulations and for editing operations that are subject to constraints.

The European project ELECTRA is concerned with the introduction of multimedia / telematics support to enhance the accessibility (local, regional and international) of learning material and to promote collaborative work. For the purpose of this paper we concentrate on two workpackages in the Limburg University Centre. The Interactive Multimedia Server workpackage focuses on the design of a generic platform for the integration of different types of information related to the learning process. Special attention is given to management, integration and accessibility of study material in an electronic environment. The other workpackage investigates the use of the interactive multimedia server in Medicine education.

Abstract In the visual programming community, many interesting graphical metaphors have been reported upon for representing computer programs graphically. Most of them have a 2D or 2.5D appearance on the screen in order to reflect the inherent multi‐dimensionality of the programming constructs being represented. By going into a three‐dimensional representation, this reflection can go a stepfurther. With ever increasing3D graphics rendering capabilities on todays computers, it moreover becomes feasible to extend the dimensionality of the program (and data structure) depiction. We follow this approach by realizing 3D graphical programming techniques within CAEL, our interactive Computer Animation Environment Language. The paper elucidates how several concepts, traditionally found within the Virtual Environments area, can be utilized in the realization of three‐dimensional Programming Environments.