# Patent

## Title
Curved guide member for articulating instruments

## Abstract

A loading unit is provided. The loading unit includes a housing defining a longitudinal axis, a mounting support pivotally connected to the housing and including a tool assembly operably connected thereto, a curved guide member extending between the housing and the support member, and a drive member extending through the curved guide member for actuating the tool assembly when the mounting support is articulated relative to the housing.

## Background
BACKGROUND
1. Technical Field
The present disclosure relates to surgical instruments having an articulating portion. More particularly, the present disclosure relates to a guide member for increasing the angle of articulation of the articulating portion.
2. Background of Related Art
Various instruments have been modified for use in closed procedures, i.e., laparoscopy, arthroscopy, endoscopy. Such instruments typically include an elongated body portion configured to extend through an opening in a patient, i.e., through an access port, and/or through a natural orifice, e.g., anus, mouth.
Many of these instruments adapted for closed procedures include an articulable tool assembly mounted on a distal end of an elongated body portion. The tool assembly is controlled remotely from a handle assembly mounted on the proximal end of the elongated body portion. An articulation mechanism mounted on the handle assembly allows for the remote articulation of the tool assembly relative to the elongated body portion. In many instances, the tool assembly is actuated by a drive member extending through the articulation joint. For example, loading unit 1 shown in FIG. 2 includes a drive member 2. Such drive members typically include an elongated, substantially flattened member having a proximal end operably connected to an advancement mechanism and a distal end operably received within the operable portion of the tool assembly. To assist in preventing bucking and/or bulging of drive member 2 during advancement thereof through the articulated articulation joint, loading unit 1 employs blowout plates 3.
Another means for guiding the drive assembly through the articulation joint is disclosed in U.S. Pat. No. 7,654,431 to Hueil et al. The stapler of the '431 patent includes a dog bone link for directing the drive member through the articulation joint when the articulation joint is articulated. The dog bone link is pivotally secured between the body portion of the stapler and the articulating tool assembly. The straight configuration of the link distributes the bend of the drive member at two (2) points, i.e., the proximal end and the distal end of the guide. As such, the degree to which the tool assembly may be articulated is limited. Additionally, during advancement of the drive member while the tool assembly is articulated, the drive member may become over-bent and/or over-stressed, thereby resulting in bulging and/or buckling of the drive member.
Therefore, it would be beneficial to have an articulation mechanism that includes an improved means for guiding a drive member through the articulated joint.
SUMMARY
Accordingly, a surgical instrument including an articulating loading unit is provided.
In one aspect of the present disclosure, the loading unit includes a housing defining a longitudinal axis, a mounting support pivotally connected to the housing and including a tool assembly operably connected thereto, a curved guide member extending between the housing and the support member, and a drive member extending through the curved guide member for actuating the tool assembly when the mounting support is articulated relative to the housing.
The loading unit may include a mounting support that is pivotally connected to the housing by a pair of connecting elements. A pivot point between the mounting support and the housing may be axially off-set from the longitudinal axis. The tool assembly can include an anvil and a cartridge assembly.
In certain embodiments, the drive member includes a substantially flattened member. The guide member may define a channel for receipt of the drive member.
In a further aspect of the present disclosure, a surgical stapler includes a handle assembly, an elongate body portion extending from the handle assembly, a housing defining a longitudinal axis and being disposed adjacent the distal end of the elongate body portion, a mounting support pivotally connected to the housing and including a tool assembly operably connected thereto, a curved guide member extending between the housing and the mounting support, wherein the curved guide member has a proximal tab slidably engaging the housing, and a drive member extending through the curved guide member for actuating the tool assembly when the mounting support is articulated relative to the housing.
In certain embodiments, the mounting support is pivotally connected to the housing by a pair of connecting elements. A pivot point between the mounting support and the housing may be axially off-set from the longitudinal axis. The tool assembly may include an anvil and a cartridge assembly.
In certain embodiments, the drive member includes a substantially flattened member. The guide member may define a channel for receipt of the drive member. The curved guide member, in certain embodiments, is slidably movable as the mounting support pivots.
The housing may define a slot for receiving the proximal tab. The curved guide member may have a distal tab that is connected to the mounting support. The curved guide member may have one or more walls defining a slot to receive the drive member.



DESCRIPTION OF THE DRAWINGS
Embodiments of a loading unit including a curved guide member are disclosed herein with reference to the drawings, wherein:
FIG. 1 is a perspective view of a surgical stapler including loading unit according to an embodiment of the present disclosure;
FIG. 2 is an exploded perspective view of a prior art loading unit;
FIG. 3 is a perspective view of the loading unit of FIG. 1, with the sleeve of the loading unit removed to expose the housing;
FIG. 4 is a perspective bottom view of the top half of the loading unit of FIG. 3;
FIG. 5 is a perspective top view of the bottom half of the loading unit of FIG. 3;
FIG. 6 is an exploded perspective view of the loading unit of FIG. 3;
FIG. 7 is a perspective view of the distal end of the loading unit of FIG. 3, with the mounting supports removed to show the guide member;
FIG. 8 is a perspective view of the distal end of loading unit of FIG. 3, including the support members;
FIG. 9 is a top view of the loading unit of FIG. 3;
FIG. 10 is a cross-sectional view of the loading unit of FIG. 9, taken along line 10-10 of FIG. 9;
FIG. 11 is a top view of the distal end of the bottom half of the loading unit of FIG. 3, in an articulated condition;
FIG. 12 is the top view of the distal end of the bottom half of the loading unit of FIG. 11, in a partially articulated condition; and
FIG. 13 is the top view of the distal end of the bottom half of the loading unit of FIG. 12, in a straightened conditioned.



DETAILED DESCRIPTION
An embodiment of the presently disclosed articulation mechanism including an improved guide member will now be described in detail with reference to the drawings wherein like numerals designate identical or corresponding elements in each of the several views. As is common in the art, the term “proximal” refers to that part or component closer to the user or operator, i.e. surgeon or physician, while the term “distal” refers to that part or component further away from the user.
FIGS. 1 and 3-13 illustrate an embodiment of a loading unit including a guide member according to the present disclosure, shown generally as loading unit 100. As shown in FIG. 1, and as will be discussed hereinbelow, loading unit 100 is configured for use with a surgical stapler 10 (FIG. 1). Surgical stapler 10 includes a handle assembly 20 and an elongated body 30 extending from handle assembly 20. The structure and function of surgical stapler 10 will only be described herein to the extent necessary to fully disclose loading unit 100. For a more detailed description of the structure and function of a surgical stapler similar to surgical stapler 10, please refer to commonly owed U.S. Pat. No. 5,865,361 to Milliman et al., the content of which is incorporated herein in by reference in its entirety.
Although the guide member of the present disclosure will be described as relates to a loading unit for use with a surgical stapler, it is envisioned that the disclosed guide member may be modified for incorporation into any device having an articulating joint and a flattened drive member extending through the articulating joint. It is further envisioned that the guide member of the present disclosure may be incorporated directly into a surgical device rather than as part of a loading unit.
With reference to FIGS. 1 and 3-6, loading unit 100 and includes a housing 102 defining a longitudinal axis “x”, a sleeve 104 (FIG. 6) configured to be received about housing 102, a pair of mounting members 120, 130 pivotally connected to a distal end 102b of housing 102 and a curved guide member 140 (FIG. 6) operably extending between a distal end 102b of housing 102 and mounting members 120, 130. A proximal end 102a of housing 102 is configured for operable engagement with an actuation mechanism, i.e., handle assembly 20 via elongated body 30 (FIG. 1).
Still referring to FIGS. 1 and 3-6, housing 102 of loading unit 100 includes upper and lower housing halves 106, 108. Each of upper and lower housing halves 106, 108 defines a channel 106a (FIG. 4), 108a (FIG. 5), respectively, formed along the length thereof which, when upper and lower housing halves 106, 108 are assembled, form a longitudinal passage 105 (FIG. 11). As will be discussed in further detail below, longitudinal passage 105 is configured to slidingly receive a drive member 150 (FIG. 6) configured for actuating tool assembly 50. Each of first and second housing halves 106, 108 further define a slot 107a, 107b formed along respective channels 106a, 108a. As will be discussed in further detail below, slot 107a is configured to receive a proximal tab 142a of guide member 140 and slot 107b is configured to receive a proximal tab 144a of guide member 140. Each of upper and lower housing halves 106, 108 define a recess 109a, 109b, respectively formed on an outer surface of the distal ends thereof. Recesses 109a, 109b are configured to receive first and second connecting elements 110, 112, respectively.
With particular reference now to FIG. 6, first connecting member 110 extends distally from first housing half 106 and second connecting member 112 extends distally from second housing half 108. A proximal end 110a of first connecting member 110 is configured to be received within recess 109a of first housing half 106. A proximal end 112a of second connecting member 112 is configured to be received within recess 109b of second housing half 106. First and second connecting elements 110, 112 may be secured to distal end 102b of housing 102 using fasteners, bonding, adhesive or any other suitable method. As shown, first and second connecting elements 110, 112 are retained within respective recesses 109a, 109b by sleeve 104 received about housing 102.
Each of first and second connecting elements 110, 112 define an opening 111, 113, respectively, in a distal end 110b, 112b thereof. Openings 111, 113 are configured to receive tabs 122, 132 formed in proximal ends 120a, 130a of mounting supports 120, 130, respectively. Connecting elements 110, 112 are configured such that openings 111, 113 are off-set from longitudinal axis “x” of loading unit 110. As will be discussed in further detail below, first and second connecting elements 110, 112 operate to pivotally connect first and second mounting supports 120, 130 to housing 102.
With continued reference to FIG. 6, first and second mounting supports 120, 130 are configured for operable connection with a tool assembly 50 (FIG. 1). As shown, tool assembly 50 includes an anvil 52 and a cartridge assembly 54. As discussed above, although the aspects of the present disclosure are described as relates to surgical stapling device 10 (FIG. 1), it is envisioned that the curved guide member of the present disclosure may be modified for use with other tool assemblies, e.g., graspers, clip appliers. For a more detailed discussion of the structure and operation of a tool assembly similar to tool assembly 50, please refer to commonly owned U.S. Pat. No. 5,865,361 to Milliman et al.
Each of first and second mounting supports 120, 130 define a channel 120a, 130a. First and second mounting supports 120, 130 are configured such that, when assembled, channels 120a, 130a form a longitudinal passage 129 (FIG. 9) through which drive member 150 is received. First mounting support 120 includes a tab 122 formed on a proximal end 120a thereof for reception within opening 111 formed in first connecting member 110. Second mounting support 130 includes a tab 132 (FIG. 11) formed on a proximal end 130a thereof for reception within opening 113 formed in first connecting member 110. Each of first and second mounting supports 120, 130 include a cut-away portion 121 (FIG. 4), 131 (FIG. 5), respectively, configured to accommodate guide member 140 as first and second mounting supports 120, 130 are pivoted relative to distal end 102b of housing 102. Each of first and second mounting supports 120, 130 define an opening 123, 133, respectively, configured to receive proximal tabs 142b, 144b of upper and lower guide halves 142, 144, respectively, of guide member 140.
Curved guide member 140 has one or more walls 143 (FIG. 7) that defines a slot 145 for receiving the drive member. The curved guide member has a pair of proximal tabs that engages the housing, the curved guide member being slidably movable as mounting supports 120, 130 pivot. Curved guide member 140 may further include a pair of distal tabs that are connected to the mounting support 120, 130. Curved guide member 140 may include more than one member to form slot 145 for receiving the drive member. For example, with reference still to FIGS. 3-13, curved guide member 140 includes upper and lower curved guide halves 142, 144. Guide halves 142, 144 each define a curved channel 143a, 143b extending the length thereof which form a longitudinal slot 145 when guide halves 142, 144 are assembled. Longitudinal slot 145 is configured to receive drive member 150 (FIG. 6) in a sliding manner therethrough. Upper guide half 142 includes a proximal tab 142a configured for reception within slot 107a of upper housing half 106 and a distal tab 144b configured to be received within opening 123 formed in first mounting support 120. Lower guide half 144 includes a proximal tab 144a configured for reception within slot 107b of lower housing half 108 and a distal tab 144b configured to be received within opening 133 formed in second mounting support 130.
With particular reference to FIGS. 7 and 8, the assembly of loading unit 100 will now be described. Although drive member 150 (FIG. 6) has been omitted from FIGS. 7 and 8 to more clearly illustrate the structure and function of the articulating portion of loading unit 100, it is appreciated that, when assembled in its entirety, drive member 150 slidably extends through distal end 102b of housing 102 to actuate a tool assembly mounted to mounting supports 120, 130.
With reference initially to FIG. 7, upper and lower curved guide halves 142, 144 are assembled to form longitudinal slot 145. Although not shown, drive member 150 (FIG. 6) is configured to extend through longitudinal slot 145. Curved guide member 140 is then received between upper and lower housing halves 106, 108 such that proximal tab 142a formed on upper guide half 142 is received within slot 107a defined by upper housing half 106 and proximal tab 144a formed on lower guide half 144 is received within slot 107b defined by lower housing half 108. As will be discussed in further detail below, slots 107a, 107b are configured such that proximal tabs 142a, 144a of upper and lower guide halves 142, 144, respectively, may slide relative to housing 102. First and second mounting supports 120, 130 are then assembled about guide member 140 such that distal tab 142b of upper guide half 142 is received within opening 123 defined by first mounting support 120 and distal tab 144 of lower guide half 142 is received within opening 133 defined by second mounting support 130. In an alternative embodiment, openings 123, 133 in first and second mounting supports 120, 130, respectively, may be replaced by slots to enable curved guide member 140 to slide relative to first and second mounting supports 120, 130 rather than sliding relative to housing halves 106, 108. First and second mounting supports 120, 130 are pivotally attached to distal end 102b of housing 102 by connecting elements 110, 112, respectively. In particular, tab 122 formed on first mounting support 120 is received within opening 111 defined by first connecting member 110 and tab 132 formed on second mounting support 130 is received within opening 113 defined by second connecting member 112. As discussed above, first and second connecting elements 110, 112 may be secured to housing 102 using any number of methods. As shown, sleeve 104 (FIG. 1) is received about housing 102 to retain first and second connecting elements 110, 112 within recesses 109a, 109b, respectively.
With reference to FIG. 9, as assembled, first and second mounting support 120, 130 are configured to pivot relative to distal end 102b of housing 102. As discussed above, first and second connecting elements 110, 112 are configured such that the pivot point for first and second mounting supports 120, 130 is off-set from longitudinal axis “x” of housing 102. This configuration is possible because of the single direction of articulation of loading unit 100. The ability to off-set the pivot point allows for optimal placement of the pivot point for minimizing the travel of drive member 150 due to articulation.
The operation of the articulating portion of loading unit 100 will now be described with particular reference to FIGS. 11-13. Referring initially to FIG. 11, loading unit 100 is provided to a clinician in a first or articulated position. In the articulated position, first and second mounting supports 120, 130 are disposed at a right angle relative to longitudinal axis “x”. In this manner, a drive member (not shown) is received through first and second mounting supports 120, 130 in a pre-bent condition. The curved configuration of guide member 140 distributes the bending of the drive member over three (3) points, i.e., the proximal and distal ends of guide member 130 and along guide member 140. This configuration is in contrast to the previously disclosed straight guide member that distributes the bending of the drive member in only two (2) points, i.e., the proximal end and distal end of the guide member. Distributing the bending of the drive member over a great number of points allows for greater articulation of the tool assembly 50 without over bending and/or over stressing drive member 150 at any one point. As seen in FIG. 11, mounting supports 120, 130, and thus tool assembly 50 (FIG. 1), may be articulated as much as ninety degrees (90°) relative to longitudinal axis “x”. As discussed above, the off-set alignment of the pivot points of first and second mounting supports 120, 130 allows for optimum placement of the pivot points to minimize travel of drive member 150 due to the articulation of loading unit 100.
Turning now to FIGS. 12 and 13, once loading unit 100 is operably connected to handle assembly 20, the articulated portion of loading unit 100 requires straightening in order for laparoscopic insertion through an opening, e.g., access port, natural orifice. First and second mounting supports 120, 130, and thus, tool assembly 50 mounted thereto, may be straightened to a non-articulated position (FIG. 13) using any known technique. For example, an articulation linkage (not shown) may extend through loading unit 100 and operably connect to an articulation lever 25 mounted on handle assembly 20. As first and second mounting supports 120, 130 pivot relative to housing 102, proximal tabs 142a, 144a of guide member 140 slide within slots 107a, 107b formed in housing 102 to accommodate the movement of guide member 140. Once received within the body cavity, first and second mounting supports 120, 130 are pivoted back to an articulated position (FIG. 11). In the event it is necessary for tool assembly 50 to be articulated to the left instead of the right, as shown, loading unit 100 may be configured to rotate about longitudinal axis “x” to change the direction of articulation.
Stapler 10 is then used in a traditional manner to staple and cut tissue. Following use of stapler 10 (FIG. 1), first and second mounting supports 120, 130 are pivoted relative to housing 102 to return loading unit 100 to the non-articulated position (FIG. 11) to permit withdrawal of loading unit 100 from within the body cavity.
Any of the embodiments disclosed herein may be included on a surgical stapler that does not have a loading unit 100 that includes a tool assembly. It is contemplated that a surgical stapler having a tool assembly can have a removable and replaceable cartridge.
It will be understood that various modifications may be made to the embodiment disclosed herein. For example, the loading unit may be configured to articulate to the left instead of the right. Furthermore, as discussed above, the slots for permitting movement of the guide member during articulation may be formed within the first and second mounting supports instead of being formed within housing 102, as described. The housing may have holes instead of slots. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

## Claims

1. A loading unit comprising:
a housing defining a longitudinal axis;
a mounting support pivotally connected to the housing and including a tool assembly operably connected thereto, the mounting support movable between a first position in alignment with the longitudinal axis and a second position articulated relative to the longitudinal axis;
a guide member extending between the housing and the mounting support, the guide member defining a curved longitudinal slot when the mounting support is in the first position; and
a drive member extending through the curved longitudinal slot of the guide member for actuating the tool assembly when the mounting support is in the second position.

2. The loading unit of claim 1, wherein the mounting support is pivotally connected to the housing by a pair of connecting elements.

3. The loading unit of claim 1, wherein a pivot point between the mounting support and the housing is axial off-set from the longitudinal axis.

4. The loading unit of claim 1, wherein the tool assembly includes an anvil and a cartridge assembly.

5. The loading unit of claim 1, wherein the drive member includes a substantially flattened member.

6. The loading unit of claim 1, wherein the guide member is slidably movable relative to the housing as the mounting member pivots between the first and second positions.

7. The loading unit of claim 1, wherein the guide member includes first and second proximal tabs and the housing includes first and second slots, the first and second tabs being slidably movable within the first and second slots.

8. The loading unit of claim 1, wherein the guide member includes first and second guide halves.

9. The loading unit of claim 8, wherein each of the first and second guide halves define a channel which together form the curved longitudinal slot.

10. A surgical stapler comprising:
a handle assembly;
an elongate body portion extending from the handle assembly;
a housing defining a longitudinal axis and being disposed adjacent the distal end of the elongate body portion;
a mounting support pivotally connected to the housing and including a tool assembly operably connected thereto;
a curved guide member extending between the housing and the mounting support, wherein the curved guide member includes upper and lower guide halves each having a proximal tab that slidably engages the housing; and
a drive member extending through the curved guide member for actuating the tool assembly when the mounting support is articulated relative to the housing.

11. The surgical stapler of claim 10, wherein the mounting support is pivotally connected to the housing by a pair of connecting elements.

12. The surgical stapler of claim 10, wherein a pivot point between the mounting support and the housing is axial off-set from the longitudinal axis.

13. The surgical stapler of claim 10, wherein the tool assembly includes an anvil and a cartridge assembly.

14. The surgical stapler of claim 10, wherein the drive member includes a substantially flattened member.

15. The surgical stapler of claim 10, wherein each of the first and second guide halves of the curved guide member defines a curved channel which together form a curved longitudinal slot for receipt of the drive member.

16. The surgical stapler of claim 10, wherein the curved guide member is slidably movable as the mounting support pivots.

17. A surgical stapler, comprising:
a handle assembly;
an elongate body portion extending from the handle assembly;
a housing defining a longitudinal axis and a slot, the housing being disposed adjacent the distal end of the elongate body portion;
a mounting support pivotally connected to the housing and including a tool assembly operably connected thereto;
a curved guide member extending between the housing and the mounting support, wherein the curved guide member includes a proximal tab slidably received within the slot in the housing such that the guide member is slidably movable as the mounting support pivots; and
a drive member extending through the curved guide member for actuating the tool assembly when the mounting support is articulated relative to the housing.

18. The surgical stapler of claim 17, wherein the curved guide member has a distal tab that is connected to the mounting support.

19. A surgical instrument comprising:
an elongate body defining a longitudinal axis;
a mounting support pivotally connected to the elongate body, the mounting support movable between a first position in alignment with the longitudinal axis and a second position articulated relative to the longitudinal axis,;
a guide member extending between the elongate body and the mounting support, the guide member defining a curved longitudinal slot having a fixed radius of curvature when the mounting support is in the first position and when the mounting support is in the second position; and
a drive member extending through the curved longitudinal slot of the guide member.