Sharif Digital Repository

Needle insertion into the soft tissue has been the subject of many studies during the last decade, while needle control has become a crucial training tool, evaluating surgeon's skills in such critical incision. This study considers a model-based dynamics equation for the needle movement through the soft tissue. In the proposed model, the force distribution along the needle shaft is estimated through the use of tissue deformation data and tissue model. A novel algorithm for the needle control simulation is also proposed based on the developed dynamics equation of the needle movement. To point out the role of mechanical properties of the soft tissue, an inverse dynamics control method is used... 

In this paper, model-based and distrbance observer (DOB)-based control of needle in precautious applications are compared. In the model-based approach, the force acting on the needle is calculated by evaluating the finite element model (FEM) of the tissue with the tissue deformation. In DOB-based method, the force acting on the needle is considered as an external disturbance and it is estimated using position and velocity of the needle. In both approaches, the calculated/estimated force is used in a sliding mode control scheme to steer the needle to the target. A dynamics equation for the movement of the needle is proposed which includes the force applied by the tissue to the needle. The... 

Although 'Needle steering' is considered a challenge in needle insertion strategies, needle control becomes a crucial training tool for evaluating surgeon's skills in such critical incision. In this study, a model-based dynamics equation for the needle movement through the soft tissue is developed. In the proposed control scheme, the force estimation calculated through the simulated tissue deformation data and the dynamic finite element as the tissue model, is used as the force feedback. To point out the role of mechanical properties of the soft tissue, an inverse dynamics control method is used to demonstrate the system performance in presence of uncertainty in tissue mechanical parameters....