A mass-spring-damper model for real time simulation of the frictional grasping interactions between surgical tools and large organs

Considering the loss of direct visual and tactile information, surgeons require special training programs to obtain sucient prociency for laparoscopic surgery. Surgical training simulation systems provide an eective alternative to animal models for repetitive training practices. The purpose of this study was to develop a biomechanical model of large soft organs for simulation of the interactions of a surgical grasper and spleen in real-time. The mechanical behavior of the spleen was molded in detail, including its nonlinear hyper viscoelastic properties using a mass-spring-damper model. A novel collision detection algorithm was used to determine the tool-tissue contact zones. Forcebased and geometry-based boundary conditions were imposed at the contact nodes, respectively, to represent slippage-included and slippage-free grasping conditions. The modelʹs predictions were validated against the experimental results on a synthetic test sample. Results of simulation of interactions between the grasping tool and the spleen organ indicated that the non-linear rate dependent and stress relaxation behaviors of the tissue was well depicted by the model. Also, the model was capable of re ecting the eect of tool-tissue friction coecient on the slippage-free or slippage-included grasping behaviors.