title: Dynamic cylindrical free-form deformation for interactive simulation of tool-tissue interaction.
abstract: BACKGROUND
  Dynamic lattice-based free-form deformation (FFD) allows efficient simulation of global deformation of complex geometric objects. However, directly imposing a number of position constraints due to contact with a tool is non-trivial since it is an over-determined problem.
  
  
  METHODS
  This paper extends the FFD to directly impose a number of position constraints for the objects to be embedded in (rounded) cylindrical lattice structures. The position constraints are applied by enabling each surface point to locally deform along the near-normal direction to the surface.
  
  
  RESULTS
  The computational time of the local deformation is independent of the number of constrained points other than finite element method. As a real-time application, the proposed method is applied to colonoscopic polypectomy simulation running at over 60 Hz.
  
  
  CONCLUSIONS
  The proposed method allows efficient simulation of the global and local deformations of complex geometric objects while achieving accurate tool-tissue interaction in a realistic and robust manner.
authors.affiliation: Rensselaer Polytechnic Institute, Troy, NY, USA.
authors.forename: Woojin
authors.initials: W
authors.lastname: Ahn
authors.forename: Doo Yong
authors.initials: DY
authors.lastname: Lee
mesh_terms: D003196:Computer Graphics; D003198:Computer Simulation; D055119:Elastic Modulus; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008328:Man-Machine Systems; D008954:Models, Biological; D025321:Surgery, Computer-Assisted / Q000379:methods*; D013525:Surgical Instruments; D014584:User-Computer Interface