Our overall goal is to develop and validate the paradigm of a Real-Time Haptic Immersive Virtual Environment (RT- HIVE) for enhanced human manipulation performance in a variety of application arenas. Their principal promise lies in the ability to expand, assist, train and monitor human sensorimotor capabilities for improving physical strength as in augmenting the manual precision, as in scaling motions and forces and as in dexterity.

The overall kinesthetic immersive experience is the synthesis of the human user, the haptic user interface (HUI) and virtual environment (VE) – all of which play critical roles. The virtual environment refers to the computer-based model, capable of interactively generating cues for immersion of multiple senses of the user. While early VEs were restricted to generation of visual and auditory cues, contemporary VEs have been extended (using “haptic models”) to encompass the generation of kinesthetic cues. The HUI is to denote the computer controlled electromechanical system (“haptic device”), the feedback control laws (“haptic control laws”) as well as all the intermediate elements (A/D, D/A, conditioning electronics) that help interface the motions and forces between the human operator and the virtual environment. The effectiveness of the interface – in communicating the human user intent to the virtual environment and rendering of the results back to the users – can be judged using performance benchmarks such as the fidelity, transparency, stability, accuracy and real-time interactivity. The differences from the traditional paradigm of human-computer interaction arise due: (i) the far higher bandwidth of kinesthetic and tactile perception (over 1000 Hz vs the 30 Hz for visual perception); and (ii) the bi-directional exchange of information and energy often conflict with the requirement maintaining real-time interactivity and overall system stability. Critical trade-offs, in terms of bandwidth, fidelity and accuracy are required for development of “suitable haptic models” for generating responses to dynamic user interactions with the virtual world as well as “suitable haptic interfaces” to render the resulting computation without attenuation or interference.

Many of these aspects can be seen frequently in the context of skill-and-strength training of human performance of manipulation tasks for audiences ranging from astronauts, pilots, surgeons to assembly line operators. While many such skills can be inexpensively trained on the missions or on physical mockups, the requirements and logistics of some application arenas preclude such an approach. We will focus our attention on one such arena – virtual-cadaver-based anatomy training – in a case study to elaborate on the issues and challenges.