Instrument with a counter-pivoting mechanism

An instrument comprising:

• an elongate shaft having a proximal portion and a distal portion;
• a counter-pivoting mechanism comprising:
• a first joint coupled to the distal portion of the elongate shaft, the first joint comprising a first link;
• a second joint disposed distally of the first joint, the second joint comprising a second link;
• an elongate tube disposed between the first joint and the second joint and having a central lumen extending along a longitudinal axis of the elongate tube;
• and
• a plurality of constraint cables extending between the first and second joints within a plurality of channels formed in a wall of the elongate tube;
• and
• a plurality of control cables extending through the elongate shaft and configured to control manipulation of the counter-pivoting mechanism, wherein the plurality of control cables wraps helically around at least a portion of the elongate tube within a plurality of grooves formed in an outer circumferential surface of the wall of the elongate tube,
• wherein the first and second joints are coupled by the plurality of constraint cables such that as the counter-pivoting mechanism is manipulated by the plurality of control cables, the first joint pivots in a first direction as the second joint pivots in a second direction opposite the first direction while the first link and the second link are maintained in a parallel orientation.

An instrument comprising:

• an elongate shaft having a proximal portion and a distal portion;
• an end effector;
• a counter-pivoting mechanism disposed between the elongate shaft and the end effector, the counter-pivoting mechanism comprising:
• a first joint coupled to the distal portion of the elongate shaft, the first joint comprising a first link;
• a second joint disposed distally of the first joint, the second joint comprising a second link;
• an elongate tube disposed between the first joint and the second joint and having a central lumen extending along a longitudinal axis of the elongate tube;
• and
• a plurality of constraint cables extending between the first and second joints through the elongate tube;
• a plurality of control cables extending through the elongate shaft and configured to control manipulation of the counter-pivoting mechanism, wherein the plurality of control cables are disposed external to the central lumen of the elongate tube, wherein the first and second joints are coupled by the plurality of constraint cables such that as the counter-pivoting mechanism is manipulated by the plurality of control cables, the first joint pivots in a first direction as the second joint pivots in a second direction opposite the first direction while the first link and the second link are maintained in a parallel orientation;
• and
• a plurality of end effector control cables extending through the elongate shaft and the central lumen of the elongate tube and configured to manipulate the end effector.

An instrument comprising:

• an elongate shaft having a proximal portion and a distal portion;
• an end effector;
• a counter-pivoting mechanism disposed between the elongate shaft and the end effector, the counter-pivoting mechanism comprising:
• a first joint coupled to the distal portion of the elongate shaft;
• a second joint disposed distally of the first joint;
• an elongate tube disposed between the first joint and the second joint and having a central lumen extending along a longitudinal axis of the elongate tube;
• and
• a plurality of constraint cables extending between the first and second joints through the elongate tube;
• and
• a plurality of control cables extending through the elongate shaft and configured to control manipulation of the counter-pivoting mechanism, wherein the plurality of control cables extend non-linearly through the elongate tube, wherein the first and second joints are coupled by the plurality of constraint cables such that as the counter-pivoting mechanism is manipulated by the plurality of control cables, the first joint pivots in a first direction as the second joint pivots in a second direction while a portion of the instrument proximal of the counter-pivoting mechanism is maintained parallel to a portion of the instrument distal of the counter-pivoting mechanism.