Modeling and simulation of friction forces during needle insertion using Local Constraint Method

In modern clinical practices, accurate orientation for needle-like tools inserting into soft tissues is cumbersome, mainly due to the tissue´s non-linear deformation and the complicated combination of forces between the tissue and the tool. In this paper, the interaction between tissue deformation and friction forces has been discussed. We consider the relative velocity and contact length as the main factors of friction force during tissue deforming. An available friction model has been built for dynamic needle insertion simulation based on Finite Element (FE) framework. A Local Constraint Method (LCM) is proposed to calculate the tissue deformation and apply the friction forces to the tissue frame for avoiding remeshing. In our approach a series of equivalent constraints and forces are generated by decomposing them inside Local Regions (LRs) to nodal points. Simulations based on this method to realize the dynamic needle insertion have been conducted for validation.