Finite element methods for real-time haptic feedback of soft-tissue models in virtual reality simulators

Applies the linear elastic finite element method to compute haptic force feedback and domain deformations of soft-tissue models for use in virtual reality simulators. Our results show that, for virtual object models of high-resolution 3D data (>10,000 nodes), haptic real-time computations (<500 Hz) are nor currently possible using traditional methods. Current research efforts are focused in the following areas: (1) efficient implementation of fully adaptive multi-resolution methods, and (2) multi-resolution methods with specialized basis functions to capture the singularity at the haptic interface (point loading). To achieve real-time computations, we propose parallel processing of a Jacobi pre-conditioned conjugate gradient method applied to a reduced system of equations resulting from surface domain decomposition. This can effectively be achieved using reconfigurable computing systems such as field programmable gate arrays (FPGAs), thereby providing a flexible solution that allows for new FPGA implementations as improved algorithms become available. The resulting soft-tissue simulation system would meet NASA Virtual Glovebox requirements and, at the same time, provide a generalized simulation engine for any immersive environment application, such as biomedical/surgical procedures or interactive scientific applications.