Haptic interaction with deformable models for 3D liver segmentation

We present a tool for interactive 3D liver segmentation using deformable surface models represented by simplex meshes. The interaction is performed directly in 3D with a haptic device. We use volume haptics to convey information about the volumetric data used for external force computations. This helps us to better understand the data and adjust the deformation weights. It is also possible to interact directly with the mesh during deformation. By pointing the haptic probe like a “torch” at the mesh, vertices and faces in a user specified neighbourhood are selected and forces can be applied to the selected sub-mesh only. We performed an experiment where 10 segmentations of the liver from CT data was performed. The segmentation results show high sensitivity and specificity when compared to manual delineations made by a radiologist.