Joan De Boeck

Arm training in Multiple Sclerosis using Phantom: Clinical relevance of robotic outcome measures

Upper limb weakness due to Multiple Sclerosis has a major negative effect on the functional activities of the patient. Promising developments in the field of rehabilitation robotics may enable additional exercise. This study aims to investigate which types of robotic outcome measures are clinically relevant, in preparation of the evaluation for intervention studies.Within this context, appropriate movement tasks and tests for the haptic PHANTOM end-effector robot were designed in a virtual environment. These tasks focused on spatial accuracy, object manipulation and speed. Outcome measures were: 1) virtual movement tests, recorded by the robot to quantify motor control; 2) clinical outcome measures such as the Motricity Index, Jamar and MicroFET hand-held dynamometer to evaluate muscle strength; and the Nine Hole Peg Test, Purdue Pegboard, ARAt and TEMPA to asses upper limb function and manual dexterity.10 healthy controls performed the virtual movement tasks using the Phantom as interface. 21 MS subjects with upper limb dysfunction caused by muscle weakness were included in an interventional training study. Pearson correlations were calculated at baseline between the performance on the three virtual movement tasks and the clinical tests on impairment and activity level. The virtual movement tests discriminated between healthy controls and MS patients with hand dysfunction. In the MS patient group, no significant correlations were found between muscle strength tests and virtual movement tasks, while mainly significant correlations were found between specific functional measures (specifically ARAt and Purdue pegboard test) and virtual movement tasks.

An interactive coal mine museum visit: Prototyping the user experience

Interactive software applications are increasingly finding their way to cultural and tourist sites. During the development of a coal mine museum on the former mine site of Beringen (Province of Limburg, Belgium), we explored the possibilities of such interactive systems, suitable for the specific site and the intended target group. In particular, we concentrated on a mobile location-based educational game allowing young visitors to gain insight in the life of the miner, and on an interactive virtual environment (VE) giving the visitor an overview of the vast site, highlighting interesting locations. In this paper we share our experiences with several prototyping techniques in the context of user-centred design (UCD). The different prototyping techniques are chosen depending on the goal and the kind of prototype. Furthermore we describe the interplay between the created prototypes and the applied prototyping techniques.

Designing context-aware multimodal virtual environments

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.

Exploiting proprioception to improve haptic interaction in a virtual environment

3D environments are designed to be intuitive and easy to use. However, when defining interaction in 3D virtual environments, suitable paradigms for accessing objects and user interface elements are often difficult to determine. Several solutions currently exist, all with their strengths and weaknesses, but due to the complexity of the human senses and technical and financial restrictions, none of them is ideal. In this paper, we describe a first step in our research investigating how 3D interaction can be improved by introducing a technique that uses proprioception together with realistic force feedback in order to more easily access objects and widgets in 3D space. In a user experiment, we also validate our newly proposed solution, and compare it to our earlier work.

Computers Helping People with Special Needs

In this paper we propose a visual-based speech learning framework to assist deaf persons by comparing the lip movements between a student and an E-tutor in an intelligent tutoring system. The framework utilizes lip reading technologies to determine if a student learns the correct pronunciation. Different from conventional speech recognition systems, which usually recognize a speaker’s utterance, our speech learning framework focuses on recognizing whether a student pronounces are correct according to an instructor’s utterance by using visual information. We propose a method by extracting dynamic shape difference features (DSDF) based on lip shapes to recognize the pronunciation difference. The preliminary experimental results demonstrate the robustness and effectiveness of our approach on a database we collected, which contains multiple persons speaking a small number of selected words.

Target Acquisition with Force Feedback: The Effect of Different Forces on the User's Performance

Besides realistic haptic rendering of objects, haptic feedback can also be used to provide an abstract feedback channel. This can either be realised by a tactile or a force feedback stimulus. When using forces, care has to be taken that the users performance is not influenced in a negative way. However, as it is not obvious to determine a suitable force, and currently not many guidelines exist. Therefore, in this paper we investigate the influence on some important parameters that define a force (shape, duration and amplitude). In order to compare different forces, we propose to use the definite integral (Force Integral, FI ) which combines the considered parameters. From the conducted experiment we learn that the FI can be used (within bounds) to make an estimation of the result of the force. Besides this, we also found that above a given FI value, the users performance degrades significantly.

EasyICT: a framework for measuring ICT-skills of people with cognitive disabilities

Over the last decade, the basic skills to operate a computer (ICT skills) are an essential requirement to participate in the current digital era. People not possessing these skills are likely to miss access to education, entertainment, business and social life. In particular for people with cognitive limitations, this is a real threat. In the EasyICT project, we aimed at the development of a training and assessment framework, supported by an on-line tool. Using this tool youngsters with mental disabilities can be systematically tested for their ICT skills. As a result, they receive a report and additional training material in order to improve their skills.

Force Feedback Magnitude Effects on User's Performance during Target Acquisition: A Pilot Study

Only a few guidelines exist for defining the force properties in a haptic interface; as a consequence, they are mostly determined in an ad-hoc manner. We investigate how the users performance changes during target acquisition when increasing force amplitudes are applied. Using a simple multidirectional point-select task, forces with variable amplitudes are applied to the user while traversing from one target to the other. We find that the users performance suddenly degrades significantly, rather than decreasing progressively. This finding may be important for defining guidelines which forces may and may not be applied to a user in order to allow the haptic feedback to improve, rather than deteriorate the users performance.

Haptic linear paths for arm rehabilitation in MS patients

Force feedback in the context of a rehabilitation program may have its benefits. The generated forces can be used to assist, support or oppose the patients according to their personal needs and abilities. Using the Phantom haptic device, we conducted a pilot study focussing on the rehabilitation of the upper limbs in MS patients. Apart from the promising clinical results, we found that only a few haptic effects are commonly necessary. Among them is a ‘linear path’, a haptic effect that generates the necessary forces to follow a path defined by two or more points in space. In this paper we motivate why the current implementations in existing haptic APIs (such as H3D) are not completely suitable. We propose two possible alternative implementations based on our requirements: one using rounded polygons, another using cardinal splines. It will turn out that both solutions are equivalent, but depending on the application one of both will be more suitable.

Future challenges of model-based design

When we consider models in model-based design (MBD) approaches in the HCI field, we can say that the first generation of tool for user interface construction was based on database models. The second generation of MBD approaches includes models such as the user model, task model, cognitive model, system model etc. However, the third generation of models is the one facing current and future challenges. In this summary report, we present our discussion on the future challenges of MBD.