Real-time interactive isosurfacing: a new method for improving marching isosurfacing algorithm output and efficiency

Abstract

Efficient rendering of a changing volumetric data-set is central to the development of effective medical simulations that incorporate haptic feedback. A new method referred to as real-time interactive isosurfacing (RTII) is described in this paper. RTII is an algorithm that can be applied to output from Marching Cubes-like algorithms to improve performance for real-time applications. The approach minimises processing by re-evaluating the isosurface around changing sub-volumes resulting from user interactions. It includes innovations that significantly reduce mesh complexity and improve mesh quality as triangles are created from the Marching Tetrahedra isosurfacing algorithm. Rendering efficiency is further improved over other marching isosurfacing algorithm outputs by maintaining an indexed triangle representation of the mesh. The effectiveness of RTII is discussed within the context of an endoscopic sinus surgery simulation currently being developed by the authors.

Comparing surgical experience with performance on a sinus surgery simulator

“…The aim was to remove all of the unhealthy tissue while minimizing the amount of healthy tissue removed. This tissue model builds upon prior work by adding a real‐time deformable surface while providing force feedback via the haptic controller to simulate the feel of the tissue. The unhealthy tissue was twice the stiffness and twice the density compared with the healthy tissue, to enable users to gain knowledge of the tissue remaining via palpation.…”

Validation of virtual‐reality‐based simulations for endoscopic sinus surgery

“…The task required the user to remove a discoloured region of tissue from a larger tissue model. The tissue model (described by Ruthenbeck et al) 14 was hemispherical in shape and deliberately abstract (unlike any real organ or anatomical region). The haptic device was used to control a stylus (depicted as a small white sphere) that could either palpate or volumetrically remove tissue when the haptic device button was pressed.…”