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This paper describes evaluation experiments for visual and auditory feedback in a virtual obstacle walking scenario. Two studies with healthy subjects were carried out using the actuated gait orthosis LOKOMAT. Controlled factors for the visual feedback experiment were three different perspectives and 2D/3D vision. In the auditory feedback experiment, controlled factors were rhythmic distance feedback and gradual foot clearance feedback. For the visual and auditory feedback experiments, outcome was assessed with task-specific performance parameters and questionnaires. Results for visual feedback indicate that the chosen side perspective is superior to behind and ego perspectives. It is also shown that 3D vision does not reduce the number of obstacle hits compared to 2D vision. Furthermore, it is demonstrated that adding continuous auditory feedback made subjects walk faster compared to the exclusive use of visual feedback. Subjects rated auditory distance feedback as more helpful than auditory foot clearance feedback. Therefore, we suggest using side perspective and auditory feedback on obstacle distance.

Efficient rowing requires both physical and technical abilities of the human. Teaching and learning of the technical abilities is thereby mainly restricted to on-water training. The aim of this project was to develop a rowing simulator. This simulator should serve as a high-level indoor training tool that can be used by rowing novices and professionals. The users should perceive acoustic, visual, and haptic cues about their current performance and their environment in real time.The newly-developed rowing simulator consists of a rowing boat hull equipped with multiple position sensors attached to the oar and seat. The boat hull was mounted on a podium placed inside a Cave setup. The Cave comprises projection screens, a loudspeaker system, and actuated winches for visual, acoustic, and haptic feedback, respectively. A mathematical real-time rowing model was developed, which computes the boat velocity and the oar force as a function of the movement of the oar and the user. All relevant boat, oar, and user parameters can be arbitrarily set, thus allowing the simulation of different boat types.The rowing model was validated by comparing results of the simulation with data from on-water measurements. Both the boat velocity and the oar force predicted by the model correlated highly with the experimentally-obtained data. Furthermore, the rowing simulator was successfully tested with professional rowers who rated the level of realism and the applicability of the simulator for indoor training as high. Based on the feedback of the rowers, various hardware and software extensions are planned for the simulator, including an increase of the number of actuated degrees of freedom of the boat and the oar, in order to improve the haptic feedback. r

Highly immersive environments for sports simulation can help elucidate if and how athletes perform under high pressure situations. We used a rowing simulator with a CAVE setup to test the influence of virtual competitors on 10 experienced rowers. All participants were using the simulator for the first time. The objective was to assess the degree of presence by quantifying how the actions of the virtual competitors triggered behavioral changes in the experienced rowers. The participants completed a virtual 2000 m race with two competing boats, one being behind and one ahead of the participant. For two trials, each boat would come closer to the participant without overtaking, resulting in four experimental conditions. The behavior of the participants was assessed with biomechanical variables, questionnaires, and an interview after the race. Behavioral changes were detected with statistically significant differences in the extracted variables of oar angles, timing variables, velocities, and work. The results for biomechanical variables indicate individual response patterns depending on perception of competitors and self-confidence. Self-reporting indicated a high degree of presence for most participants. Overall, the experimental paradigm worked but was compromised by perceptive and subjective factors. In future, the setup will be used to investigate rowing performance further with a focus on motor learning and training of pressure situations.

Virtual environments increase participation of children with cerebral palsy in robot-aided treadmill training Virtual environments increase participation of children with cerebral palsy in robot-aided treadmill training Abstract Virtual environments can make repetitive motor rehabilitation exercises more motivating and thereby more effective. We hypothesize that participation-dependent multimodal stimuli increase the patientpsilas activity as expressed through force exertion during robot-aided treadmill training. In a single case study with one patient (12 years old), we were able to show that active participation increased in the presence of visual stimuli and decreased in their absence. For a feasibility study, we included four children with cerebral palsy in order to assess the user acceptance of four different virtual environment scenarios including a soccer scenario, a traffic situation, obstacle crossing and wading through deep snow. Using questionnaires, we found that only the soccer scenario provided sufficient interactive elements to engage the patients.Abstract-Virtual environments can make repetitive motor rehabilitation exercises more motivating and thereby more effective. We hypothesize that participation-dependent multimodal stimuli increase the patient's activity as expressed through force exertion during robot-aided treadmill training. In a single case study with one patient (12 years old), we were able to show that active participation increased in the presence of visual stimuli and decreased in their absence. For a feasibility study, we included four children with cerebral palsy in order to assess the user acceptance of four different virtual environment scenarios including a soccer scenario, a traffic situation, obstacle crossing and wading through deep snow. Using questionnaires, we found that only the soccer scenario provided sufficient interactive elements to engage the patients.