Laparoscopic instrument with parallel actuated jaws

• US 6,238,414 B1
• Filed: 01/20/2000
• Issued: 05/29/2001
• Est. Priority Date: 01/20/2000
• Status: Expired due to Term

• Current Assignee: Aspen Surgical Products Incorporated (Aspen Surgical Products Holdings Incorporated)
• Original Assignee: Tnco, Inc. (Symmetry Medical Inc)
• Inventors: Griffiths, Jerry R.
• Primary Examiner(s): TRUONG, KEVIN THAO
• Application Number:
  US09/488,057
• Time in Patent Office: 495 Days
• Field of Search: 606/205, 606/206, 606/207, 606/208, 606/50, 606/51, 606/52, 606/170, 606/167
• US Class Current: 606/205
• CPC Class Codes: A61B 17/29 Forceps for use in minimally invasive surgery
• CPC Class Codes: A61B 2017/2926 Details of heads or jaws
• CPC Class Codes: A61B 2017/2939 Details of linkages or pivot points
• CPC Class Codes: A61B 2017/2944 Translation of jaw members

Abstract

A surgical instrument including a handle assembly, and end effector mechanism including jaws, an elongated shaft assembly having a longitudinal actuation rod linearly reciprocating within a hollow sheath, slidably connecting the handle assembly to the jaws. Jaws having first and second grasping members have a mechanically controlled linkage assembly enabling the jaws to be adapted such that they can only open in parallel relationship to each other. The linkage assembly having a pair of toggle links which are rotatively connected to a linear translation member to cause the jaws to open or close. The linkage assembly further having a pair of stabilizing links, which at one end are pivotally anchored to a non-reciprocal movement member, and at an opposite end interconnected with the jaws to maintain the opposing serrated grasping surfaces of the jaws in a parallel relationship to each other.

Claims

1. a surgical instrument of the laparoscopic type comprising:

a) a handle assembly having means for actuating the instrument;

b) a shaft assembly comprising a hollow sheath and an actuation rod disposed for axial movement within the sheath, wherein the sheath and the actuation rod each have a proximal end and a distal end, the proximal end of the actuation rod reciprocally connected to the actuation means of the handle assembly; and

c) an end effector mechanism operatively associated with the distal end of the actuation rod, the mechanism comprising;

a pair of grasping members operable to open and close in parallel face to face relation to each other in response to movement by the handle assembly,

a front end housing connected to the distal end of the sheath, the front end housing having a cavity defined therein,

a linkage assembly having means for pivotally interconnecting the jaw members to the front end housing,

a translation member coaxially disposed within the cavity, having means for reciprocally connecting to the actuation rod and rotatively connecting to the linkage assembly wherein linear motion of the actuation rod is translated to rotational direction in the linkage assembly, whereby the grasping members are adapted to respond to the actuation motion of the handle assembly to thereby open or close the grasping members in parallel relationship to each other throughout their range of motion, and

the pivotally interconnecting means of the linkage assembly comprises;

a pair of toggle link elements, each toggle link having a forward end pivotally connecting with the corresponding grasping member, each toggle link having a proximal end for pivotally anchoring to the front end housing, each toggle link further having a linking yoke defined on the proximal end for rotatively connecting to the translation member, whereby linear motion of the translation member will adapt the forward ends of the toggle links to rotate either outwardly or inwardly to either open or close the grasping member; and

a pair of stabilizing link elements positioned outside of and generally parallel to the toggle links, each stabilizing link having a forward end pivotally connecting to the grasping member, each stabilizing link having a proximal end pivotally connecting with the front end housing, wherein in response to movement by the toggle links, the stabilizing links will pivot in a geometrically controlled manner, thereby maintaining the parallel relationship of the grasping members to each other throughout their movement,

whereby a retracted actuation by the handle assembly will cause the grasping members to open in a parallel relation to each other, while an extended actuation will cause the grasping members to close.

2. The instrument according to claim 1, wherein the grasping members are jaw members having opposing serrated surfaces.

3. The instrument according to claim 2, wherein the jaw members include a first jaw member and a second jaw member, each jaw member includes:

a rear end portion having an upper arm, a lower arm and a central support extension;

the upper arm and central support extension forming an upper slot therebetween, the upper slot being of sufficient width to slidably receive the forward end of one of the toggle links, the upper arm having a pivot pin to pivotally connect the toggle link within the upper slot; and

the lower arm and central support extension forming a lower slot therebetween, the lower slot having sufficient width to slidably receive the forward end of one of the stabilizing links, the lower arm having a pivot pin to pivotally connect the stabilizing link within the lower slot,

whereby each jaw member is pivotally connected to the toggle link which is adapted to urge the jaw either open or closed, and each jaw member is pivotally connected to the stabilizing link which is adapted to maintain the serrated surfaces of the jaws in a parallel relationship to each other.

4. The instrument according to claim 3, wherein for connecting to the sheath the front end housing for connecting to the sheath comprises a cylindrical rear end portion adapted to be press-fitted into the distal end of the sheath.

5. The instrument according to claim 4, wherein the front end housing comprises:

a forward portion having a pair of generally parallel spaced flanges extending therefrom,

the flanges having interior surfaces defining a generally rectangularly shaped channel of sufficient size to slidably accept the proximal ends of the toggle link elements, a center pin pivotally anchoring the toggle links to the front end housing;

the flanges each have a recess defined therein of sufficient width to slidably accept the proximal ends of the stabilizing links, flange pivot pins pivotally connecting the stabilizing links to the front end housing,

whereby the front end housing pivotally anchors the links to eliminate linear motion therein.

6. The instrument according to claim 5, wherein the means for reciprocally connecting the translation member to the actuation rod comprises a pair of rod supports, an upper rod support and a lower rod support, each rod support extending from a rear portion of the translation member, each rod support having an inner circular surface defining an open-sided sleeve of sufficient diameter to accept the distal end of the actuation rod, each rod support having means for riveting to the actuator member,

whereby the translation member will reciprocate the linear movement of the activation rod.

7. The instrument according to claim 6, wherein the translation member comprises:

a pair of ears extending from a forward end,

a groove defined by the interior surfaces of each ear, to allow room for linear motion of the translation member within the front end housing; and

a yoke pin integrally mounted on the exterior surface of each ear for rotatively connecting with the linking yoke of the corresponding toggle link element,

whereby linear motion of the translation member is converted into generally vertical motion by action of the toggle links, such that a retracted linear motion will subsequently cause the jaws to open and an extended linear motion will cause the jaws to close.

8. The instrument according to claim 1, wherein the actuating means of the handle comprises:

a stationary handle component with an extending barrel portion;

a movable handle component that is pivotally connected to the barrel portion; and

the barrel portion having means for connecting to the proximal end of the actuation rod

whereby the user, upon squeezing the handle components together, will cause the jaw members to close in parallel to each other, and by extending the handle components will cause the jaw members to open.

9. A surgical instrument of the laparoscopic type comprising the combination of:

a) a handle assembly having a stationary handle with an extending barrel portion, a movable handle that pivots in relationship to the stationary handle for operating the instrument;

b) a shaft assembly having a hollow sheath and an actuation rod reciprocally and coaxially transposed within the sheath, a proximal end of the actuation rod having means for connecting to the barrel portion of the handle assembly,

whereby motion of the movable handle will cause the actuation rod to reciprocate in a longitudinal linear movement relative to the sheath; and

c) an end effector mechanism having;

a front end housing having a rear end portion press-fitted into a distal end of the shaft assembly, a cavity defined within the housing, a forward section having a yoke-like structure,

a pair of jaw members for gripping an object,

a translation member reciprocally transposed with the cavity of the front end housing, means for operatively associating the translation member with the distal end of the actuation rod, the means comprising of a pair of rod supports extending outwardly from a rear end portion, the rod supports having circular inner surfaces defining an open-sided sleeve of sufficient diameter to slidably receive the actuation rod,

a pair of ears extending from a forward section of the translation member, the ears comprising a first ear and a second ear, the ears each having a yoke pin integrally mounted on its exterior surface, and

a linkage assembly pivotally connecting the front end housing and yoke pins of the translation member to the jaw members for translating pivotal movement of the handle assembly to the jaw members,

whereby the jaws will open or close in parallel relationship to each other throughout their range of motion in response to pivotable motion of the movable handle.

10. The instrument according to claim 9, wherein the linkage assembly includes:

a pair of toggle links, a first toggle link and a second toggle link, each toggle link having a linking yoke defined on its proximal end for rotatively connecting to corresponding yoke pins of the translation member;

means for pivotally anchoring the proximal end of each toggle link to the front end housing; and

each toggle link having a forward end for pivotally engaging with one of the jaw members,

whereby the linear reciprocating motion imparted by the actuation rod is adaptably translated to the yoke pins of the translation member, thereby causing the link yokes of each toggle link to rotatively pivot to either push open the jaws or to pull close the jaws.

11. The instrument according to claim 10, wherein the linkage assembly includes:

a pair of stabilizing links, a first stabilizing link and a second stabilizing link, each stabilizing link having a proximal end for pivotally connecting with the front end housing, each stabilizing link having a forward end for pivotally connecting to a corresponding jaw member,

whereby upon rotative movement of the toggle links causing the jaws to either open or close, the geometrical structure and positioning of the stabilizing links prevents the jaws from being able to move in anything but a parallel face to face relationship to each other.

12. The instrument according to claim 11, wherein the jaw members include a first jaw member and a second jaw member, each jaw member includes:

an opposing serrated surfaces for grasping the object;

a rear portion having an upper arm, a lower arm and a central support extension;

the upper arm and central support extension cooperating to form an upper slot therebetween, the upper slot being of sufficient width to slidably accept the forward end of the toggle links, the upper arm having an upper pivot pin pivotally connecting the toggle link within the upper slot; and

the lower arm and central support extension cooperating to form a lower slot therebetween, the lower slot having sufficient width to receive the forward end of one of the stabilizing links, the lower arm having a lower pivot to pivotally connect the stabilizing link within the lower slot,

whereby each jaw member is pivotally connected to a toggle link which is adapted to urge the jaw members either open or closed, and each jaw member is pivotally connected to a stabilizing link which is adapted to maintain the serrated surfaces of the jaws in a parallel relationship to each other throughout their range of motion.

13. The instrument according to claim 12, wherein the means for affixing the actuation rod to the translation member comprises a rivet passing through the rod supports and actuation rod.

14. The instrument according to claim 12, wherein the means for anchoring the toggle links to the front end housing comprises:

the forward section of the front end housing having a pair of extending flanges, the flanges defining a channel therebetween of sufficient size to accept the proximal ends of the toggle links, a center pin pivotally anchoring the toggle links within the channel.

15. The instrument according to claim 14, wherein each of the flanges of the front end housing has a recess defined therein of sufficient width to slidably receive the proximal end of one of the stabilizing links, a pivot pin in each flange for pivotally connecting the stabilizing link within the recess.