Endoscopic surgery training using virtual reality and deformable tissue simulation

Surgical training systems based on virtual reality (VR) and simulation techniques for tissue deformation may represent a more cost-e!ective and e$cient alternative to traditional training methods. Additionally, VR is a technology that can teach surgeons new procedures and can determine their level of competence before they operate on patients. At Forschungszentrum Karlsruhe (FZK), a virtual reality training system for minimally invasive surgery (MIS), based on the simulation software KISMET, has been developed. An overview of the current state of development for the `Karlsruhe Endoscopic Surgery Trainera is presented. For quick and easy creation of surgical scenes containing deformable anatomical organ models, the spline-based modeller KisMo has been developed, which generates beside the geometry also a spatial mass}spring network of the objects for the elastodynamic simulation in KISMET. The MIS trainer provides several surgical interaction modules for deformable objects like grasping, application of clips, cutting, coagulation, injection and suturing. Additionally, it is possible to perform irrigation and suction in the operation area. Active deformable objects are used for the morphodynamic simulation of the stomach and the intestines. Furthermore, a hierarchical pulse simulation in virtual arterial vessel trees has been realized, which enables the palpation of the pulse with a force-feedback device. The pulse simulation is coupled with an arterial bleeding simulation, which gets activated by injuries of arteries and stopped by application of clips. The simulation system has been applied to minimally invasive surgery training in gynaecology and laparoscopy. Special attention is addressed to elastodynamically deformable tissue models and geometric modelling techniques for graphical real-time performance. ( 2000 Elsevier Science Ltd. All rights reserved.