Curved cannula instrument

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,
• a shaft that extends from the transmission mechanism to the surgical end effector, the shaft comprising a push/pull drive element and a plurality of force isolation elements,
• wherein the transmission mechanism comprises a force transmission interface to a robotic manipulator,
• wherein the end effector comprises a movable component,
• wherein the shaft is passively flexible and comprises a support tube,
• wherein the support tube comprises a central channel and a plurality of force isolation element channels around the central channel,
• wherein the push/pull drive element is positioned in the central channel and is coupled to the movable component,
• wherein one of the plurality of force isolation elements is positioned in a corresponding one of the plurality of force isolation element channels, and
• wherein the force isolation elements isolate the push/pull drive element from movement as a result of bending of the shaft as the shaft translates through the cannula.

A surgical instrument comprising:

• a proximal end transmission mechanism, wherein the transmission mechanism comprises a force transmission interface to a robotic manipulator of a surgical system;
• a distal end surgical end effector comprising a movable component;
• and
• a shaft that extends from the transmission mechanism to the surgical end effector;
• wherein the shaft is passively flexible;
• wherein the shaft comprises a drive element coupled to the movable component of the end effectors;
• wherein the shaft comprises a force isolation element rod;
• and
• wherein the force isolation element rod isolates the drive element from movement as the result of a bending of the shaft as the shaft translates through a cannula having a portion with a curved longitudinal axis.