Patent ID: 8551115

Claim:
A robotic surgical system comprising: a rigid cannula comprising at least a portion that has a curved longitudinal axis; and a surgical instrument configured to be advanced through the cannula, the instrument comprising: a proximal end transmission mechanism, a distal end surgical end effector, and a shaft that extends from the transmission mechanism to the surgical end effector, wherein the transmission mechanism comprises a force transmission interface to a robotic manipulator, wherein the shaft is passively flexible, wherein the shaft comprises a push/pull drive element positioned along a longitudinal centerline of the shaft and at least three force isolation elements spaced equally around the push/pull drive rod, wherein the force isolation elements isolate the push/pull drive element from movement as a result of a bending of the shaft as the shaft translates through the cannula, wherein the end effector comprises a movable component, and wherein the push/pull drive element is coupled to the movable component.