Force modeling for needle insertion into soft tissue based on mechanical properties and geometric parameters

The force model during needle insertion into soft tissue is important for accurate percutaneous intervention.In this paper,a force model for needle insertion into a tissue- equivalent material is presented and a series of experiments are conducted to acquire data from needle soft- tissue interaction process.In order to build a more accurate insertion force model,the interaction force between a surgical needle and soft tissue is divided into three parts:stiffness force,friction force,and cutting force.The stiffness force is modeled on the basis of contact mechanics model.The friction force model is presented using a modified Winkler' s foundation model.The cutting force is viewed as a constant depending on a given tissue.The proposed models in the paper are established on the basis of the mechanical properties and geometric parameters of the needle and soft tissue.The experimental results illustrate that the force models are capable of predicting the needle-tissue interaction force.The force models of needle insertion can provide real-time haptic feedback for robot-assisted procedures,thereby improving the accuracy and safety of surgery.