A compact dynamic force model for needle-tissue interaction.

In this paper, the interaction force between a surgical needle and soft tissue is studied. The force is modeled using nonlinear dynamics based on a modified LuGre model that captures all stages of needle-tissue interaction including puncture, cutting, and friction forces. An estimation algorithm for identifying the associated parameters is then presented. This approach, which is based on extended Kalman filtering (EKF), enables us to characterize the interaction with a mathematical model in the force domain. It compares the axial force measured at the needle base with its expected value and then adapts the model parameters to represent the actual interaction. To evaluate the performance of our model, experiments were performed on an artificial phantom.