Force transmission mechanism for surgical instrument, and related systems and methods
A surgical instrument may comprise a chassis, a shaft coupled to the chassis at the proximal end of the shaft, an end effector coupled to the shaft at the distal end of the shaft, a force transmission mechanism coupled to the chassis, and an actuation element connected between a lever arm of the force transmission mechanism and the end effector. The force transmission mechanism includes a worm drive, and the lever arm comprising a first end and a follower member at the first end of the lever arm, wherein the follower member is engaged with the worm drive and is configured to be driven by the worm drive. Rotational movement of the worm drive imparts translational movement to the actuation element via the lever arm, and the lever arm slides along a generally linear direction relative to the chassis to impart the translational movement to the actuation element.
1. An instrument, comprising:
a shaft extending between a proximal end and a distal end, the shaft having a longitudinal axis extending through the proximal and distal ends;
a movable component at the distal end of the shaft;
a force transmission mechanism at the proximal end of the shaft; and
an actuation element operably coupled to and extending from the movable component to the force transmission mechanism, the actuation element extending through the shaft substantially parallel to the longitudinal axis of the shaft;
wherein the force transmission mechanism comprises:
a worm drive, and
a linkage operably coupled to the actuation element and engaged with the worm drive,
wherein rotational movement of the worm drive imparts linear translational movement to the linkage; and
wherein linear translational movement of the linkage imparts linear translational movement to the actuation element.
2. The instrument of claim 1 , wherein the linkage comprises a first link portion engaged with the worm drive and a second link portion coupled to the actuation element and coupled to the first link portion.
3. The instrument of claim 2 , wherein the linkage comprises a monolithic body with the first link portion and the second link portion being integrally connected parts of the monolithic body.
4. The instrument of claim 2 , wherein the first link portion and the second link portion are separate parts coupled together.
5. The instrument of claim 2 , wherein:
the linear translational movement of the linkage comprises linear translational movement of the first link portion along the worm drive,
the linear translational movement of the first link portion along the worm drive imparts linear translational movement to the second link portion along a direction parallel to a rotational axis of the worm drive, and
linear translational movement of the second link portion imparts the linear translational movement to the actuation element.
6. The instrument of claim 2 , wherein the second link portion extends from the first link portion along a direction perpendicular to an axis of rotation of the worm drive.
7. The instrument of claim 6 , wherein the second link portion is coupled to a post extending parallel to the axis of rotation of the worm drive such that the second link portion is slidable along the post.
8. The instrument of claim 7 , wherein the actuation element is coupled to the second link portion at a location between the post and the first link portion.
9. The instrument of claim 1 ,
wherein an axis of rotation of the worm drive is parallel to and offset from the longitudinal axis of the shaft.
10. The instrument of claim 1 , wherein the worm drive comprises a threaded section defining a spiral groove between thread portions of the threaded section, and at least a portion of the linkage is received within the spiral groove of the worm drive.
11. The instrument of claim 1 , wherein the movable component comprises a jaw mechanism.
12. The instrument of claim 11 , wherein the actuation element is operably coupled to the jaw mechanism to drive opening and closing of the jaw mechanism.
13. The instrument of claim 1 , wherein the actuation element is a push-pull drive element.
14. The instrument of claim 1 , wherein the movable component comprises an end effector or a wrist mechanism.
15. A teleoperable system, comprising:
a manipulator arm comprising an actuation interface; and
the instrument of claim 1 ,
wherein the instrument is mountable to the actuation interface, and
the actuation interface is configured to drive rotational movement of the worm drive in a mounted state of the instrument to the actuation interface.
16. The instrument of claim 1 , wherein the linear translational movement of the linkage imparts the linear translational movement to the actuation element along a direction parallel to an axis of rotation of the worm drive.
17. An instrument, comprising:
a shaft extending between a proximal end and a distal end of the shaft;
a movable component coupled at the distal end of the shaft;
a force transmission mechanism coupled to the shaft and located along the shaft proximally of the movable component; and
an actuation element operably coupled to and extending from the movable component to the force transmission mechanism, the actuation element extending through the shaft substantially parallel to the longitudinal axis of the shaft;
wherein the force transmission mechanism comprises;
an actuation input mechanism removably engageable with an actuation interface of a manipulator arm of a manipulator external to the instrument, the actuation input mechanism configured to be driven by the actuation interface of the manipulator in an engaged state with the actuation interface,
a worm drive operably coupled with and configured to be driven by the actuation input mechanism, and
a linkage operably coupled to the actuation element and engaged with the worm drive,
wherein rotational movement of the worm drive imparts linear translational movement to the linkage; and
wherein linear translational movement of the linkage imparts linear translational movement to the actuation element.
18. The instrument of claim 17 , wherein the linear translational movement of the linkage imparts the linear translational movement to the actuation element along a direction parallel to an axis of rotation of the worm drive.