Mechanical manipulator for surgical instruments
A novel mechanical system, based on a new cable driven mechanical transmission, able to provide sufficient dexterity, stiffness, speed, precision and payload capacity to actuate multi-DOF micro-manipulators. Besides the possibility of being used in several articulated surgical instruments and robotic systems for surgery or other applications involving remote manipulation, it enables the design of a novel fully mechanical surgical instrument, which offer the advantages of conventional laparoscopy (low cost, tactile feedback, high payload capacity) combined with the advantages of single port surgery (single incision, scarless surgery, navigation through several quadrants of the abdominal cavity) and robotic surgery (greater degrees of freedom, short learning curve, high stiffness, high precision, increased intuition). The unique design of the proposed system provides an intuitive user interface to achieve such enhanced maneuverability, allowing each joint of a teleoperated slave system to be driven by controlling the position of a mechanically connected master unit.
1. A mechanical teleoperated surgical device for surgical procedure, the device comprising:
a support tube having a distal region and a proximal region;
a slave unit disposed at the distal region of the support tube, the slave unit comprising:
a plurality of slave links interconnected by a plurality of slave joints;
a plurality of slave driven pulleys coupled to the plurality of slave joints, each of the plurality of slave driven pulleys configured to actuate a degree of freedom; and
a plurality of slave actuation pulleys configured to actuate the plurality of slave driven pulleys;
an end-effector connected to a distal end of the slave unit;
a master unit disposed at the proximal region of the support tube, the master unit comprising:
a plurality of master links interconnected by a plurality of master joints;
a plurality of master driven pulleys coupled to the plurality of master joints, each of the plurality of master driven pulleys configured to actuate a degree of freedom and connected to each of the plurality of slave driven pulleys configured to actuate a same degree of freedom; and
a plurality of master actuation pulleys configured to actuate the plurality of master driven pulleys, the plurality of master actuation pulleys directly connected to the plurality of slave acutation pulleys;
a handle connected to the master unit for operating the mechanical teleoperated surgical device;
a cable driven transmission system coupled between the slave unit and the master unit, the cable driven transmission system comprising a plurality of cables, each of the plurality of cables coupling the plurality of master and slave actuation pulleys and respective plurality of master and slave driven pulleys such that contact force applied on the handle transmits motion between the slave and master units via the cable driven transmission system to move the end-effector at a predetermined selected ratio relative to movement at the handle responsive to the contact force applied thereon; and
an external positioning mechanism coupled to the support tube and configured to provide the support tube movement in four degrees-of-freedom about an incision point.
2. The mechanical teleoperated surgical device of claim 1 , wherein the cable driven transmission system is configured such that each of the plurality of slave links of the slave unit and each of the corresponding plurality of master links of the master unit move substantially parallel to each other when the mechanical teleoperated surgical device is operated.
3. The mechanical teleoperated surgical device of claim 2 , wherein the end-effector comprises at least three articulated end-effector links interconnected by end-effector joints and wherein the handle comprises at least three articulated handle links interconnected by handle joints.
4. The mechanical teleoperated surgical device of claim 3 , wherein a kinematic model of a chain formed by the at least three articulated end-effector links and end-effector joints of the end-effector is identical to a kinematic model of a chain formed by at least three articulated handle links and handle joints of the handle.
5. The mechanical teleoperated surgical device of claim 4 , wherein the cable driven transmission system is configured such that each of the at least three articulated end-effector links and each of the at least three articulated handle links move substantially parallel to each other when the mechanical teleoperated surgical device is operated.
6. The mechanical teleoperated surgical device of claim 4 , wherein the predetermined selected ratio between the handle and the end-effector corresponds to a ratio between a length of each handle links and a length of each of the at least three articulated end-effector links.
7. The mechanical teleoperated surgical device of claim 1 , wherein the mechanical teleoperated surgical device is configured to move in seven degrees-of-freedom.
8. The mechanical teleoperated surgical device of claim 1 , wherein the force applied on the handle transmits motion between the slave and master units via a first set of the plurality of cables coupling the plurality of slave actuation pulleys and respective plurality of slave driven pulleys to move the end effector in a first degree-of-freedom, and
wherein the force applied on the handle transmits motion between the slave and master units via a second set of the plurality of cables coupling the plurality of slave actuation pulleys and respective plurality of slave driven pulleys to move the end-effector in a second degree-of-freedom.
9. The mechanical teleoperated surgical device of claim 8 , wherein the force applied on the handle transmits motion between the slave and master units via a third set of the plurality of cables coupling the plurality of slave actuation pulleys and respective plurality of slave driven pulleys to move the end-effector in a third degree-of-freedom.
10. The mechanical teleoperated surgical device of claim 8 , wherein the mechanical teleoperated surgical device is configured to move in seven degrees-of-freedom.
11. The mechanical teleoperated surgical device of claim 1 , wherein each of the slave and master units has an anthropomorphic kinematic model, resembling a simplified kinematics of a human arm.
12. The mechanical teleoperated surgical device of claim 1 , wherein at least one of the joints of the master and slave units is of pivot type, where a longitudinal axis of two adjoining links are not aligned and an angle between them changes with a movement of the joint, and wherein at least one of the joints of the master and slave units is of co-axial type, where a longitudinal axis of two adjoining links are aligned or are in a parallel configuration.
13. The mechanical teleoperated surgical device of claim 1 , wherein the plurality of cables coupling the plurality of slave actuation pulleys and respective plurality of slave driven pulleys comprises at least one transmission loop of flexible and/or rigid elements mounted to transmit a motion from each of the plurality of master driven pulleys of the master unit to the plurality of slave driven pulleys of the slave unit configured to actuate the same degree of freedom.
14. The mechanical teleoperated surgical device of claim 13 , wherein the at least one transmission loop is in the form of cable(s), belt(s) or chain(s).
15. The mechanical teleoperated surgical device of claim 14 , wherein each of the plurality of slave and master joints of respective slave and master units comprises at least one co-linear joint idler tube, through which motion is transmitted between proximal and distal transmission loops of the at least one transmission loop.
16. The mechanical teleoperated surgical device of claim 13 , wherein each of the plurality of slave and master joints of respective slave and master units comprises at least one co-linear joint idler tube, through which motion is transmitted between proximal and distal transmission loops of the at least one transmission loop.
17. The mechanical teleoperated surgical device of claim 1 , wherein the master unit and/or slave unit is connected to the support tube by a coupling unit, which allows the structural connection/disconnection of the master and/or slave units and the cable driven transmission system.
18. The mechanical teleoperated surgical device of claim 1 , wherein each of the master and slave units can be locked in a stationary configuration when a surgeon is not holding the handle and when the device is in an active position.
19. The mechanical teleoperated surgical device of claim 1 , wherein each of the slave and master units comprises two slave manipulators and two master manipulators, respectively, each of the two master manipulators configured to be operated independently from the other.
20. The mechanical teleoperated surgical device of claim 1 , further comprising an adjustable articulated supporting structure to insert, position and move the slave unit within an abdominal cavity of a patient, allowing passage of the support tube through an incision realized on the patient.
21. The mechanical teleoperated surgical device of claim 1 , wherein the support tube has an internal channel adapted to receive a surgical instrument and/or an endoscopic camera.
22. The mechanical teleoperated surgical device of claim 1 , wherein a kinematic model of a chain formed by the plurality of slave links and slave joints of the slave unit is identical to a kinematic model of a chain formed by the plurality of master links and master joints of the master unit.