Elastodynamic shape modeler: A tool for defining the deformation behavior of virtual tissues

A main goal of surgical simulators is the creation of virtual training envi ronments for prospective surgeons. Thus, students can rehearse the various steps of surgical procedures on a computer system without any risk to the p atient. One main condition for realistic training is the simulated interact ion with virtual medical devices, such as endoscopic instruments. In partic ular, the virtual deformation and transection of tissues are important. For this application, a neuro-fuzzy model has been developed, which allows the description of the visual and haptic deformation behavior of the simulated tissue by means of expert knowledge in the form of medical terms. Patholog ic conditions affecting the visual and haptic tissue response can be easily changed by a medical specialist without mathematical knowledge. By using t he personal computer-based program Elastodynamic Shape Modeler, these condi tions can be adjusted via a graphical user interface. With a force feedback device, which is similar to a real laparoscopic instrument, virtual deform ations can be performed and the resulting haptic feedback can be felt. Thus , use of neuro-fuzzy technologies for the definition and calculation of vir tual deformations seems applicable to the simulation of surgical interventi ons in virtual environments.