Towards kinematic modeling of a multi-DOF tendon driven robotic catheter

This paper presents a recent study on kinematic modeling of a remote-controlled active catheter. The tip steering motion of the catheter is actuated in a tendon-driven manner. Two antagonistic groups of tendon actuation realize the distal tip deflecting with two-degree-of-freedom (2-DOF) allowing it to reach a considerable large spatial workspace without catheter shaft rotation. However, when modeling such bending deformation, the sequential rotation approach is easily misapplied. We address this problem and introduce a novel and unified modeling methodology based on the concept of simultaneous rotation and the use of Rodrigues´ rotation formula. An accurate model is created for robotic catheters and also can be generalized to common multi-tendon-driven continuum manipulators. It is essential in achieving accurate control and improving autonomous execution of command tracking tasks.