Constraint-based technique for haptic volume exploration

Journal ArticleWe present a haptic rendering technique that uses directional constraints to facilitate enhanced exploration modes for volumetric datasets. The algorithm restricts user motion in certain directions by incrementally moving a proxy point along the axes of a local reference frame. Reaction forces are generated by a spring coupler between the proxy and the data probe, which can be tuned to the capabilities of the haptic interface. Secondary haptic effects including field forces, friction, and texture can be easily incorporated to convey information about additional characteristics of the data. We illustrate the technique with two examples: displaying fiber orientation in heart muscle layers and exploring diffusion tensor fiber tracts in brain white matter tissue. Initial evaluation of the approach indicates that haptic constraints provide an intuitive means for displaying directional information in volume data

An augmented haptic interface as applied to flow visualization

A novel 3D computer interface is proposed in which a physical handle containing force sensors and capable of simulating virtual touch through force feedback is coupled to a variety of virtual tools in a 3D virtual environment. The visual appearance of each tool reflects its capabilities. At one moment a user might feel they are holding a virtual grabber, activated by squeezing, and at another moment they are holding a virtual turntable activated by physical motion of a virtual wheel. In this way it is intended that form and function can be combined so that users rapidly learn the functional capabilities of the tools and retain this learning. It is also intended that the tools be easy to use because of intuitive mappings of forces to actions. A virtual environment is constructed to test this concept, and an evaluation of the interface conducted

Multimodal feedback cues on manual lifting in virtual environments

Improper manipulation of real-world objects increases the risk of developing work- related back injuries. In an effort to reduce such a risk and encourage appropriate lifting and moving methods, a Virtual Environment (VE) was employed. Virtual simulations can be used for ergonomic analysis. In this work, the VEs made use of multiple feedback techniques to allow a person to estimate the forces acting on their lower back. A person's head and hand movements were tracked in real-time whilst manipulating an object. A NIOSH lifting equation was used to calculate and determine the Lifting Index whereby the results were conveyed in real time. Visual display feedback techniques were designed and the effect of cues to enhance user performance was experimentally evaluated. The feedback cues provide the user with information about the forces acting on their lower back as they perform manual lifting tasks in VEs. Four different methods were compared and contrasted: No Feedback, Text, Colour and Combined Colour and Text. This work also investigated various types of auditory feedback technique to support object manipulation in VEs. Auditory feedback has been demonstrated to convey information in computer applications effectively, but little work has been reported on the efficacy of such techniques, particularly for ergonomic design. Four different methods were compared and contrasted: No Feedback, White-noise, Pitch and Tempo. A combined Audio-Visual (AV) technique was also examined by mixing both senses. The effect of Tactile Augmentation was also examined. Three different weights (real) were used and the results obtained by experiment were compared with the experiment using virtual weights in order to evaluate whether or not the presence of a real weighted object enhanced people's sense of realism. The goals of this study were to explore various senses of feedback technique (visual, auditory and tactile), compare the performance characteristics of each technique and understand their relative advantages and drawbacks.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Multimodal feedback cues on manual lifting in virtual environments

Improper manipulation of real-world objects increases the risk of developing work- related back injuries. In an effort to reduce such a risk and encourage appropriate lifting and moving methods, a Virtual Environment (VE) was employed. Virtual simulations can be used for ergonomic analysis. In this work, the VEs made use of multiple feedback techniques to allow a person to estimate the forces acting on their lower back. A person's head and hand movements were tracked in real-time whilst manipulating an object. A NIOSH lifting equation was used to calculate and determine the Lifting Index whereby the results were conveyed in real time. Visual display feedback techniques were designed and the effect of cues to enhance user performance was experimentally evaluated. The feedback cues provide the user with information about the forces acting on their lower back as they perform manual lifting tasks in VEs. Four different methods were compared and contrasted: No Feedback, Text, Colour and Combined Colour and Text. This work also investigated various types of auditory feedback technique to support object manipulation in VEs. Auditory feedback has been demonstrated to convey information in computer applications effectively, but little work has been reported on the efficacy of such techniques, particularly for ergonomic design. Four different methods were compared and contrasted: No Feedback, White-noise, Pitch and Tempo. A combined Audio-Visual (AV) technique was also examined by mixing both senses. The effect of Tactile Augmentation was also examined. Three different weights (real) were used and the results obtained by experiment were compared with the experiment using virtual weights in order to evaluate whether or not the presence of a real weighted object enhanced people's sense of realism. The goals of this study were to explore various senses of feedback technique (visual, auditory and tactile), compare the performance characteristics of each technique and understand their relative advantages and drawbacks

Abstract Shock and Vortex Visualization Using a Combined Visual/Haptic Interface

Specific rendering modes are developed for a combined visual/haptic interface to allow exploration and understanding of fluid dynamics data. The focus is on visualization of shock surfaces and vortex cores. Advantages provided by augmenting traditional graphical rendering modes with haptic rendering modes are discussed. Particular emphasis is placed on synergistic combinations of visual and haptic modes which enable rapid, exploratory interaction with the data. Implementation issues are also discussed