Johanna Renny Octavia

Adaptation in virtual environments: conceptual framework and user models

When interacting in a virtual environment, users are confronted with a number of interaction techniques. These interaction techniques may complement each other, but in some circumstances can be used interchangeably. Because of this situation, it is difficult for the user to determine which interaction technique to use. Furthermore, the use of multimodal feedback, such as haptics and sound, has proven beneficial for some, but not all, users. This complicates the development of such a virtual environment, as designers are not sure about the implications of the addition of interaction techniques and multimodal feedback. A promising approach for solving this problem lies in the use of adaptation and personalization. By incorporating knowledge of a user’s preferences and habits, the user interface should adapt to the current context of use. This could mean that only a subset of all possible interaction techniques is presented to the user. Alternatively, the interaction techniques themselves could be adapted, e.g. by changing the sensitivity or the nature of the feedback. In this paper, we propose a conceptual framework for realizing adaptive personalized interaction in virtual environments. We also discuss how to establish, verify and apply a user model, which forms the first and important step in implementing the proposed conceptual framework. This study results in general and individual user models, which are then verified to benefit users interacting in virtual environments. Furthermore, we conduct an investigation to examine how users react to a specific type of adaptation in virtual environments (i.e. switching between interaction techniques). When an adaptation is integrated in a virtual environment, users positively respond to this adaptation as their performance significantly improve and their level of frustration decrease.

Adaptive Personalized Training Games for Individual and Collaborative Rehabilitation of People with Multiple Sclerosis

Any rehabilitation involves people who are unique individuals with their own characteristics and rehabilitation needs, including patients suffering from Multiple Sclerosis (MS). The prominent variation of MS symptoms and the disease severity elevate a need to accommodate the patient diversity and support adaptive personalized training to meet every patients rehabilitation needs. In this paper, we focus on integrating adaptivity and personalization in rehabilitation training for MS patients. We introduced the automatic adjustment of difficulty levels as an adaptation that can be provided in individual and collaborative rehabilitation training exercises for MS patients. Two user studies have been carried out with nine MS patients to investigate the outcome of this adaptation. The findings showed that adaptive personalized training trajectories have been successfully provided to MS patients according to their individual training progress, which was appreciated by the patients and the therapist. They considered the automatic adjustment of difficulty levels to provide more variety in the training and to minimize the therapists involvement in setting up the training. With regard to social interaction in the collaborative training exercise, we have observed some social behaviors between the patients and their training partner which indicated the development of social interaction during the training.

As I am not you : accommodating user diversity through adaptive rehabilitation training for multiple sclerosis patients

People who suffer from Multiple Sclerosis (MS) are unique individuals with their own characteristics and rehabilitation training needs. The great variation of MS symptoms and severity of the disease elevates a need to accommodate the diversity among its patients and support adaptive personalized training to meet every patients rehabilitation needs. Our research has focused on integrating adaptivity in rehabilitation training for MS patients. We introduced the automatic adjustment of difficulty levels as a type of adaptation that can be provided in MS rehabilitation training exercises. A user study has been carried out to investigate the outcome of this adaptation. An adaptive personalized training has been provided to MS patients according to their own individual training progress, which was appreciated by the patients and the therapist. The automatic adjustment of difficulty levels is considered to provide more variety in the training and minimize the therapists involvement in setting up the training.

Investigation of Fatigability during Repetitive Robot-Mediated Arm Training in People with Multiple Sclerosis.

Background People with multiple sclerosis (MS) are encouraged to engage in exercise programs but an increased experience of fatigue may impede sustained participation in training sessions. A high number of movements is, however, needed for obtaining optimal improvements after rehabilitation. Methods This cross-sectional study investigated whether people with MS show abnormal fatigability during a robot-mediated upper limb movement trial. Sixteen people with MS and sixteen healthy controls performed five times three minutes of repetitive shoulder anteflexion movements. Movement performance, maximal strength, subjective upper limb fatigue and surface electromyography (median frequency and root mean square of the amplitude of the electromyography (EMG) signal of the anterior deltoid) were recorded during or in-between these exercises. After fifteen minutes of rest, one extra movement bout was performed to investigate how rest influences performance. Results A fifteen minutes upper limb movement protocol increased the perceived upper limb fatigue and induced muscle fatigue, given a decline in maximal anteflexion strength and changes of both the amplitude and the median frequency of EMG the anterior deltoid. In contrast, performance during the 3 minutes of anteflexion movements did not decline. There was no relation between changes in subjective fatigue and the changes in the amplitude and the median frequency of the anterior deltoid muscle, however, there was a correlation between the changes in subjective fatigue and changes in strength in people with MS. People with MS with upper limb weakness report more fatigue due to the repetitive movements, than people with MS with normal upper limb strength, who are comparable to healthy controls. The weak group could, however, keep up performance during the 15 minutes of repetitive movements. Discussion and Conclusion Albeit a protocol of repetitive shoulder anteflexion movements did not elicit a performance decline, fatigue feelings clearly increased in both healthy controls and people with MS, with the largest increase in people with MS with upper limb weakness. Objective fatigability was present in both groups with a decline in the muscle strength and increase of muscle fatigue, shown by changes in the EMG parameters. However, although weak people with multiple sclerosis experienced more fatigue, the objective signs of fatigability were less obvious in weak people with MS, perhaps because this subgroup has central limiting factors, which influence performance from the start of the movements.

Investigating the Possibility of Adaptation and Personalization in Virtual Environments

The complex nature of virtual environments customarily hinders users to interact in a natural, intuitive and optimal way. Different user characteristics are hardly taken into account when designing 3D user interfaces for virtual environments. We envision that user interaction in virtual environments can be enhanced by integrating adaptation and personalization into 3D user interfaces. Through our research, we aim to provide adaptive and personalized 3D user interfaces for enhancing user interaction in virtual environments. The establishment of a user model becomes an important first step to facilitate adaptation and personalization to the user. In order to partly construct the user model, we carried out an experiment on 3D target acquisition task with four user groups (differing in experience level and gender). In this paper, we present a general user model that will enable first-time users to benefit instantly from adaptation and personalization in virtual environments.

3DUI 2010 Contest Grand Prize Winners

The 2010 IEEE Symposium on 3D User Interfaces ran the symposiums first 3DUI Grand Prize, a contest for innovative, practical solutions to classic 3DUI problems. The authors describe the rationale for the first contest and give an analysis of all submissions. Each categorys winners also discuss their solutions.

Development of Activity-Related Muscle Fatigue during Robot-Mediated Upper Limb Rehabilitation Training in Persons with Multiple Sclerosis: A Pilot Trial.

Robot-assisted rehabilitation facilitates high-intensity training of the impaired upper limb in neurological rehabilitation. It has been clinically observed that persons with Multiple Sclerosis (MS) have difficulties in sustaining the training intensity during a session due to the development of activity-related muscle fatigue. An experimental observational pilot study was conducted to examine whether or not the muscle fatigue develops in MS patients during one session of robot-assisted training within a virtual learning environment. Six MS patients with upper limb impairment (motricity index ranging from 50 to 91/100) and six healthy persons completed five training bouts of three minutes each performing lifting tasks, while EMG signals of anterior deltoid and lower trapezius muscles were measured and their subjective perceptions on muscle fatigue were registered. Decreased performance and higher subjective fatigue perception were present in the MS group. Increased mean EMG amplitudes and subjective perception levels on muscle fatigue were observed in both groups. Muscle fatigue development during 15′ training has been demonstrated in the arm of MS patients, which influences the sustainability of training intensity in MS patients. To optimize the training performance, adaptivity based on the detection of MS patients muscle fatigue could be provided by means of training program adjustment.

Enhancing user interaction in virtual environments through adaptive personalized 3d interaction techniques

Leveraging interactive systems by integrating adaptivity is considered as an important key to accommodate user diversity and enhance user interaction A virtual environment is a highly interactive system which involves users performing complex tasks using diverse 3D interaction techniques Adaptivity has not been investigated thoroughly in the context of virtual environments This PhD research is concerned with embedding intelligence to enhance user interaction in virtual environments (i.e providing adaptive personalized 3D interaction techniques).

A Conceptual Framework for Adaptation and Personalization in Virtual Environments

When interacting in a virtual environment, users are confronted with a number of interaction techniques. These interaction techniques may complement each other, but in some circumstances can be used interchangeably. Because of this, it is difficult for the user to determine which interaction technique to use. Furthermore, the use of multimodal feedback, such as haptics and sound, has proven beneficial for some, but not all, users. This complicates the development of such a virtual environment, as the designers are not sure of the implications of the addition of interaction techniques and multimodal feedback.A promising approach for solving these problems lies in the use of adaptation and personalization. By incorporating knowledge of a user’s preferences and habits, the user interface should adapt to the current context of use. This could mean that only a subset of all possible interaction techniques is presented to the user. Alternatively, the interaction techniques themselves could be adapted, e.g. by changing the sensitivity or the nature of the feedback. In this paper, we propose a conceptual framework for realizing adaptive personalized interaction in virtual environments. Furthermore, we discuss how a user model can be built, as this model forms the important first step in implementing the conceptual framework.

Squeeze me and i'll change: An exploration of frustration-triggered adaptation for multimodal interaction

Complex 3D interaction in virtual environments may inhibit user interaction and cause frustration. Supporting adaptivity based on the detected user frustration can be considered as one promising solution to enhance user interaction. Our work proposes to provide adaptive assistance to users who are frustrated during their interaction with 3D user interfaces in virtual environments. The obtrusiveness of physiological measurements to detect frustration inspired us to investigate the pressure patterns exerted on a 3D input device for this purpose. The experiment presented in this paper has shown a great potential on utilizing the finger pressure measures as an alternative to physiological measures to indicate user frustration during interaction. Furthermore, the findings in this particular context showed that adaptation of haptic interaction was effective in increasing the users performance and making users feel less frustrated in performing their tasks in the 3D environment.