Meshless Method for Simulation of Needle Insertion into Soft Tissues: Preliminary Results

Needle insertion (placement) into human body organs is a frequently performed procedure in clinical practice. Its success largely depends on the accuracy with which the needle tip reaches the anatomical target. As the tissue deformsdue to interactions with the needle, the target tends to change its position. Onepossible way to decrease the risk of missing the target can be to account fortissue deformations when planning the needle insertion. This can be achieved byemploying computational biomechanics models to predict the tissue deformations. In this study, for computing the tissue deformations due to needle insertion, we employed a meshless formulation of computational mechanics that uses a spatial discretisation in a form of a cloud of points. We used the previously verified Meshless Total Lagrangian Explicit Dynamics (MTLED) algorithm that facilitates accurate and robust prediction of soft continua/soft tissues mechanical responses under large deformations. For modelling of interactions between the needle and soft tissues, we propose a kinematic approach that directly links deformation of the tissue adjacent to the needle with the needle motion. This approach does not require any assumptions about the exact mechanisms of such interactions. Its parameters can be determined directly from observation of the tissue sample/body organ deformations during needle insertion.