Jaw Movement Mechanism and Method for a Surgical Tool

• US 20120022584A1
• Filed: 07/23/2010
• Published: 01/26/2012
• Est. Priority Date: 07/23/2010
• Status: Active Grant

• Current Assignee: Conmed Corporation (Jefferies Financial Group, Inc.)
• Original Assignee: Conmed Corporation (Jefferies Financial Group, Inc.)
• Inventors: Sugalski, Eric, Holverson, Erik, Donnigan, Stephen, Koplin, Randall, Gregor, Michael
• Granted Patent: US 8,663,270 B2
• Time in Patent Office: Days
• US Class Current: 606/206
• CPC Class Codes: A61B 17/29 Forceps for use in minimally invasive surgery
• CPC Class Codes: A61B 18/1445 at the distal end of a shaft, e.g. forceps or scissors at the end of a rigid rod
• CPC Class Codes: A61B 2017/2936 Pins in guiding slots
• CPC Class Codes: A61B 2017/2939 Details of linkages or pivot points
• CPC Class Codes: A61B 2017/2944 Translation of jaw members
• CPC Class Codes: A61B 2018/0063 Sealing
• CPC Class Codes: A61B 2018/145 wherein the effectors remain parallel during closing and opening

Abstract

A jaw movement mechanism for surgical tools has improved mechanical efficiency and other advantages. The jaw movement mechanism controls the orientation and position of a movable jaw relative to a fixed jaw through a range of movement of the movable jaw. The jaws maintain a parallel orientation throughout a portion of the range of movement of the movable jaw. The jaws maintain an angular relationship throughout a portion of the range of movement of the movable jaw.

Claims

1. In a minimally invasive surgical tool having jaws for grasping tissue by relative transverse movement at a distal end of a shaft assembly connected to a handle assembly, the handle assembly creating relative reciprocating movement transferred through relatively stationary and movable shaft members of the shaft assembly to a jaw movement mechanism, the jaw movement mechanism including first and second pins respectively moving within first and second slots to convert the relative reciprocating movement of the shaft members into the relative transverse movement of the jaws, and an improvement comprising:

a pivot link pivotally connected between the relatively stationary shaft member and a movable one of the jaws to maintain a longitudinal position of the movable jaw during relative transverse movement independently of the pins contacting the slots.

2. A minimally invasive surgical tool defined in claim 1, wherein:

each jaw has a straight working surface; and

each slot includes at least two angularly intersecting portions oriented to move the pins to create a fully opened position where the working surfaces extend at an angular orientation to one another at a relative great transverse separation distance from one another and to create a fully closed position where the working surfaces extend in a parallel orientation to one another at a relatively adjacent transverse distance from one another.

3. A minimally invasive surgical tool as defined in claim 2, wherein:

the at least two angularly intersecting portions of each slot are further oriented to move the pins to create an intermediate position where the working surfaces extend in the parallel orientation to one another at a relatively greater transverse distance and at a relatively lesser transverse distance than the position of the working surfaces in the fully closed and fully opened positions, respectively.

4. A minimally invasive surgical tool as defined in claim 3, wherein:

at least one of the angularly intersecting portions of each slot are further oriented to move the pins to maintain the parallel orientation of the working surfaces during relative transverse movement of the jaws between the fully closed and intermediate positions.

5. A minimally invasive surgical tool as defined in claim 3, wherein:

at least one of the angularly intersecting portions of each slot includes one straight portion, the straight portion of the first slot extends generally parallel to the straight portion of the second slot, both of the straight portions of the first and second slots are non-parallel to the direction of relative reciprocating movement of the shaft members when the jaws are in either the fully closed or intermediate positions; and

the first and second pins move in the straight portions of the first and second slots when the jaws move between the intermediate and fully closed positions.

6. A minimally invasive surgical tool as defined in claim 3, wherein:

at least one of the angularly intersecting portions of both of the first and second slots includes one angularly extending portion which extend at an intersecting angle to the direction of relative reciprocating movement of the shaft members;

the angularly extending portions of the first and second slots further extend at intersecting angles with respect to one another; and

the first and second pins move in the angularly extending portions of the first and second slots when the jaws move between the intermediate and fully opened positions.

7. A minimally invasive surgical tool as defined in claim 3, wherein:

the first and second pins move respectively in the first and second slots to positions which are farther separated from one another with movement of the jaw members from the intermediate position to the fully closed position.

8. A minimally invasive surgical tool as defined in claim 1, wherein:

each jaw has a straight working surface;

each of the jaws includes an extension portion extending proximally from the working surface;

the extension portion of a first one of the jaws is rigidly connected to the relatively stationary shaft member;

the extension portion of the second jaw defines the first one of the slots which receives the first one of the pins;

the relatively movable shaft member supports the first pin;

the relatively movable shaft member defines the second one of the slots which receives the second one of the pins;

the extension portion of the second jaw supports the second pin;

the pivot link extends between opposite ends thereof;

one end of the pivot link is pivotally connected to the extension portion of the second jaw; and

the other end of the pivot link is pivotally connected to the relatively stationary shaft member.

9. A minimally invasive surgical tool as defined in claim 8, wherein:

the second pin pivotally connects the end of the pivot link to the extension portion of the second jaw.

10. A minimally invasive surgical tool as defined in claim 9, wherein:

the second pin moves transversely relative to the relatively stationary shaft member during movement of the jaws between the fully opened and the fully closed positions.

11. A minimally invasive surgical tool as defined in claim 8, wherein:

a third pin pivotally connects the end of the pivot link to the relatively stationary shaft member.

12. A minimally invasive surgical tool as defined in claim 8, wherein:

the relatively stationary shaft member comprises an interior rod having an open interior space within which the pivot link moves; and

the relative relatively movable shaft member comprises a sleeve housing having an interior which receives the interior rod and within which permits the pivot link to pivot during movement of the jaws between the fully opened and the fully closed positions.

13. A minimally invasive surgical tool as defined in claim 12, wherein:

the interior of the sleeve housing has a predetermined cross-sectional interior configuration;

the exterior of the interior rod has a predetermined cross-sectional exterior configuration; and

the predetermined cross-sectional configurations of the interior and exterior configurations of the sleeve housing and the interior rod permit relative longitudinal reciprocating movement of the sleeve housing and the rod and prevent relative rotational movement of the sleeve housing and the rod.

14. In a minimally invasive surgical tool having jaws for grasping tissue by relative transverse movement at a distal end of a shaft assembly connected to a handle assembly, the handle assembly creating relative reciprocating movement transferred through relatively stationary and movable shaft members of the shaft assembly to a jaw movement mechanism, the jaw movement mechanism including first and second pins respectively moving within first and second slots to convert the relative reciprocating movement of the shaft members into the relative transverse movement of the jaws, and an improvement comprising:

locating the first slot and the second pin within a moveable one of the jaws;

locating the first pin and the second slot within the relatively moveable shaft member;

increasing the distance between the first and second pins as the jaws are moved from a fully opened position to a fully closed position; and

decreasing the distance between the first and second pins as the jaws are moved from the fully closed position to the fully opened position.

15. A surgical tool as defined in claim 14, wherein:

the first slot and the second pin are stationary relative to each other; and

the second slot and the first pin are stationary relative to each other.

16. A surgical tool as defined in claim 15, further comprising:

a pivot link pivotally connected between the relatively stationary shaft member and the movable one of the jaws to maintain a longitudinal position of the movable jaw during relative tranverse movement independently of the pins contacting the slots.

17. A method of constraining two jaws to move between a fully opened position wherein a straight working surface of each jaw extends at an angular orientation to the straight working surface of the other jaw at a relative great transverse separation distance of the jaws from one another and to move to a fully closed position where the working surfaces extend in a parallel orientation to one another at a relatively adjacent transverse distance from one another in a minimally invasive surgical tool where the jaws are located at a distal end of a shaft assembly connected to a handle assembly which transfers relative reciprocating movement through relatively stationary and movable shaft members of the shaft assembly to a jaw movement mechanism which converts the relative reciprocating movement of the shaft members into the relative transverse movement of the jaws, comprising:

using first and second pins respectively moving within first and second slots in the jaw movement mechanism to convert the relative reciprocating movement of the shaft members into the relative transverse movement of the jaws; and

pivotally connecting a pivot link between the relatively stationary shaft member and a movable one of the jaws to maintain a longitudinal position of the movable jaw during relative transverse movement independently of the pins contacting the slots.

18. A method as defined in claim 17, further comprising:

angularly intersecting portions of each slot to move the pins to create an intermediate position where the working surfaces extend in the parallel orientation to one another at a relatively greater transverse distance and at a relatively lesser transverse distance than the position of the working surfaces in the fully closed and fully opened positions, respectively, and to move the pins in the slots to maintain the parallel orientation of the working surfaces during relative transverse movement of the jaws between the fully closed and intermediate positions.

19. A method as defined in claim 18, further comprising:

extending one straight portion of the angularly intersecting portions of the first and second slots generally parallel to one another when the jaws are in the fully closed and intermediate positions; and

moving the first and second pins the straight portions of the first and second slots when the jaws move between the intermediate and fully closed positions.

20. A method as defined in claim 19, further comprising:

extending one angularly extending portion of the angularly intersecting portions of the first and second slots at an intersecting angle to the direction of relative reciprocating movement of the shaft members;

extending the angularly extending portions of the first and second slots at intersecting angles with respect to one another; and

moving the first and second pins in the angularly extending portions of the first and second slots when the jaws move between the intermediate and fully opened positions.

21. A method as defined in claim 18, further comprising:

moving the first and second pins respectively in the first and second slots to positions which are farther separated from one another with movement of the jaw members from the intermediate position to the fully closed position.

22. A method as defined in claim 17, wherein each of the jaws includes an extension portion extending proximally from the working surface, further comprising:

rigidly connecting the extension portion of a first one of the jaws to the relatively stationary shaft member;

defining the first one of the slots which receives the first one of the pins in the extension portion of the second jaw;

supporting the first pin at the relatively movable shaft member;

defining the second one of the slots which receives the second one of the pins in the relatively movable shaft member;

supporting the second pin at the extension portion of the second jaw;

pivotally connecting the pivot link at one end to the extension portion of the second jaw; and

pivotally connecting the pivot link at the other end to the relatively stationary shaft member.

23. A method as defined in claim 22, further comprising:

pivotally connecting the end of the pivot link to the extension portion of the second jaw with the second pin.

24. A method as defined in claim 23, further comprising:

moving the second pin transversely relative to the relatively stationary shaft member during movement of the jaws between the fully opened and the fully closed positions.

25. A method as defined in claim 23, further comprising:

pivotally connecting the end of the pivot link to the relatively stationary shaft member by a third pin.

26. A method as defined in claim 23, further comprising:

using an interior rod which has an open interior space as the relatively stationary shaft member;

pivoting the pivot link within the open interior space of the interior rod while the jaws move between the fully opened and fully closed positions;

using a sleeve housing which has an interior as the relatively movable shaft member;

positioning the interior rod within the interior of the sleeve housing; and

pivoting the pivot link within the interior of the sleeve housing during movement of the jaws between the fully opened and the fully closed positions.

27. A method as defined in claim 26, further comprising:

constraining the sleeve housing and the interior rod to prevent relative rotational movement while permitting relative longitudinal reciprocating movement.