Surgical instrument with articulated end-effector
Disclosed is a surgical instrument with an articulated end-effector, such as a dissector, scissor or grasper, to enhance a surgeon's performance during various surgical procedures. The longitudinal axis of the instrument is defined by a shaft, which may be inserted into a surgical incision or trocar in a body of a patient. The articulated end-effector is mounted on the distal extremity of the instrument shaft and comprises a plurality of links interconnected by a plurality of joints, whose movements are remotely actuated by the surgeon's hands. This remote actuation is accomplished through mechanical transmission, mainly along flexible elements, which are able to deliver motion from a set of actuation elements, placed at a proximal extremity of the shaft, to the instrument's articulated end-effector. The articulated end-effector further comprises one or more movement-amplification elements that amplify the movement transmitted by the flexible elements so that the movement of the proximal actuation elements can be minimized while the fatigue resistance of the instrument is maintained or increased. In addition, this invention can provide short distances between the articulations of the end-effector and guaranteed simplified maintenance procedures if some moving links of the end-effector have to be removed.
1. An articulated instrument comprising:
an instrument tube defining the longitudinal axis of the instrument and configured to accommodate flexible transmission elements;
an articulated end-effector at a distal extremity of the instrument tube, comprising two distal end-effector links, a proximal end-effector link directly coupled to at least one of the distal end-effector links, and at least two rotation joints;
an actuator placed at a proximal extremity of the instrument tube, configured to actuate the proximal and distal end-effector links of the articulated end-effector;
flexible transmission elements, passing through the instrument tube, configured to transmit motion from the actuator to the end-effector links of the articulated end-effector; and
an amplification element directly coupled to at least one of the flexible transmission elements and to the proximal end-effector links, and configured to amplify the motion transmitted from the actuator to the end-effector links of the articulated end-effector.
2. The articulated instrument of claim 1 , wherein an actuation movement transmitted by the flexible transmission elements to the amplification element may be transmitted with some degree of amplification or reduction to the end-effector links.
3. The articulated instrument of claim 2 , wherein the motion transmission from the amplification element to the end-effector links is made through a contact force.
4. The articulated instrument of claim 3 , wherein the contact force is increased by the use of a geared geometry on the proximal end-effector links and the amplification element.
5. The articulated instrument of claim 2 , wherein the proximal end-effector link comprises at least one rigid element.
6. The articulated instrument of claim 1 , wherein the flexible transmission elements comprise elements with a flexible mechanical construction, selected from the group consisting of strings, ropes, belts and chains.
7. The articulated instrument of claim 1 , wherein the actuator is placed on a proximal articulated handle configured to be directly controlled by the hand of a user, so that user movements are transmitted to the articulated end-effector.
8. The articulated instrument of claim 1 , wherein the proximal extremity of the instrument tube is configured to be attached to a mechanical platform, so that the instrument tube is integrated as part of a master-slave telemanipulator, having the input motion of the actuators given by the movement of a proximal articulated handle.
9. The articulated instrument of claim 1 , wherein the proximal extremity of the instrument tube is configured to be removeably attached to a mechanical platform, so that the instrument tube is removably integrated as part of a master-slave telemanipulator.
10. The articulated instrument of claim 1 , wherein the proximal extremity of the instrument tube is configured to be attached to a robotic platform, so that it is integrated as part of a master-slave robotic telemanipulator, having the input motion of the actuator given by the movement of a proximal articulated handle.
11. The articulated instrument of claim 1 , wherein the amplification element transmits amplified motion from the actuator to the proximal end-effector link of the articulated end-effector via contact force between the amplification element and the proximal end-effector link.
12. The articulated instrument of claim 11 , wherein rotation of the amplification element transmits amplified motion from the actuator to the proximal end-effector link of the articulated end-effector via contact force between the amplification element and the proximal end-effector link.
13. The articulated instrument of claim 11 , wherein the amplification element comprises a curved surface which contacts the proximal end-effector link of the articulated end-effector to transmit amplified motion from the actuator to the proximal end-effector link of the articulated end-effector.
14. The articulated instrument of claim 1 , wherein the amplification element comprises two identical parts rotatable about a common axis, each identical part directly coupled to one of the flexible transmission elements.
15. A method for remotely actuating an articulated instrument, the method comprising: actuating an actuator to transmit motion from the actuator to proximal and distal end- effectors links of an articulated end-effector via flexible transmission elements, the proximal end-effector link directly coupled to at least one of the distal end-effector links, wherein motion transmitted from the actuator to the end-effector links is amplified via an amplification element directly coupled to at least one of the flexible transmission elements and to the proximal end-effector link.
16. The method of claim 15 , wherein the flexible transmission elements extend from the actuator through an instrument tube defining the longitudinal axis of the instrument to the amplification element.
17. The method of claim 15 , wherein the actuator is placed on a proximal articulated handle, and wherein actuating the actuator comprises controlling the proximal articulated handle via a hand of a user to transmit user movements to the articulated end-effector.
18. The method of claim 15 , wherein motion transmitted from the actuator to the end-effector links is amplified via a contact force between the amplification element and the proximal end-effector link.