Kinematic control of an articulated minimally invasive surgical robotic arm

The robotic arm used in minimally invasive surgery enters patient's body through a port which constrains its end-effector translation along two axes. We aim to achieve the minimally-invasive operations using a general articulated robotic arm (GARA). The algorithm is applicable to articulated robotic arm independent of its design; given only end-link is constrained. Geometric transformations based on the constraints acting on the end-link coupled with kinematic-relations obtained using conventional techniques, were used to drive a simulated 6-DOF GARA for minimally-invasive operations. The method was verified by tracing predefined planar and 3D trajectories using this simulated arm. The mean deviation of the traced trajectories was of the order of 10−03cm and the mean absolute error in maintaining remote center-of-motion (RCM) at the port was ∼0 (< 10−15 cm). The proposed method enabled a GARA to perform minimally-invasive operations without specialized design and with sufficient accuracy.