Development of a dynamic model for bevel-tip flexible needle insertion into soft tissues.

In this paper, we develop a mechanics-based dynamic model for bevel-tip flexible needle insertion into soft tissues. We use Newton-Euler formulation to account for the effect of actuation, friction, tissue interactions, and bevel-tip forces on the needle. The soft tissue deformation is modeled by finite element analysis, whereas the mechanics-based model is used to predict needle deflections due to bevel-tip asymmetry. The proposed needle-tissue model is then experimentally evaluated by comparing the needle deflections for various insertion depths in a tissue phantom with those achieved from simulations.