EP4633485A1

EP4633485A1 - Barbed sutures and devices and methods for forming barbs on sutures

Info

Publication number: EP4633485A1
Application number: EP23828477.2A
Authority: EP
Inventors: Timothy D. Kosa
Original assignee: Covidien LP
Current assignee: Covidien LP
Priority date: 2022-12-13
Filing date: 2023-11-29
Publication date: 2025-10-22
Also published as: CN120569164A; WO2024127138A1; WO2024127138A4

Abstract

A method of forming barbs on a suture includes contacting a first portion of an outer surface of an elongate body of a suture with a cutting tool of a barb cutting apparatus, and passing the cutting tool into the suture along a curved barb cutting path to form a barb in the elongate body of the suture.

Description

BARBED SUTURES AND DEVICES AND METHODS FOR FORMING BARBS ON SUTURES

FIELD

[0001] This disclosure generally relates to barbed sutures. More particularly, this disclosure relates to devices and methods for forming barbs on sutures.

BACKGROUND

[0002] Barbed sutures are known for use in medical procedures. The barbed sutures may be designed to optimize tissue holding for a particular indication. For example, in some circumstances, barbs are arranged to allow passage of the barbed suture in one direction through tissue, but to resist movement of the barbed suture in an opposite direction and, in some other circumstances, barbs are arranged bi-directionally to allow passage of a first portion of the barbed suture in a first direction through tissue and passage of a second portion of the barbed suture in a second direction through the tissue. The number of barbs on a particular suture may be influenced by a variety of factors, such as the size of the wound and the strength required to hold the wound closed. For example, in some circumstances, a large number of barbs and/or a random configuration of the barbs may be desired to achieve optimal wound closure and, in other circumstances, where the wound or tissue repair needed is relatively small, a reduced number of barbs may be desired.

SUMMARY

[0003] Devices and methods described herein for forming barbs on a suture implement a single, continuous, and smooth curved barb cut to produce a barb having attributes (e.g., anchoring strength) of a barb produced by a compound (e.g., dual angle) cut. These devices and methods are more efficient and/or economical over conventional devices and methods for forming barbs on a suture and include one or more of the following advantages: simplified tooling; simplified barb forming process by, for example, minimizing the number of steps required to produce barbs; or increased speed and/or load capacity.

[0004] In accordance with aspects of this disclosure, a method of forming barbs on a suture includes contacting a first portion of an outer surface of an elongate body of a suture with a cutting tool of a barb cutting apparatus, and passing the cutting tool into the suture along a curved barb cutting path to form a barb in the elongate body of the suture.

[0005] The method may further include applying ultrasonic energy to the cutting tool.

[0006] In aspects, passing the cutting tool into the suture further includes forming a cut in the elongate body having a generally concave shape. In some aspects, the curved barb cutting path is an arc of an ellipse and, in some aspects, the curved barb cutting path is an arc of a circle.

[0007] In aspects, passing the cutting tool into the suture includes moving the cutting tool into the suture. In some aspects, passing the cutting tool into the suture further includes moving the cutting tool from a home position spaced from the suture to a cut position disposed within the suture. In certain aspects, a depth of the barb is greatest at the cut position. In some aspects, the method further includes moving the cutting tool back to the home position after forming the barb. In certain aspects, moving the cutting tool back to the home position includes moving the cutting tool along the curved barb cutting path from the cut position to the home position. In some aspects, moving the cutting tool back to the home position includes moving the cutting tool through a full elliptical rotation. In certain aspects, the method further includes moving the suture after moving the cutting tool from the home position to the cut position.

[0008] In aspects, the cutting tool includes a linear knife blade. In some aspects, passing the cutting tool into the suture further includes moving the linear knife blade through an arc that follows the curved barb cutting path.

[0009] In aspects, the cutting tool includes a curved knife blade. In some aspects, passing the cutting tool into the suture includes moving the curved knife blade linearly into the elongate body.

[0010] In accordance with aspects of this disclosure, a barb cutting apparatus includes a suture retaining assembly including a gripper for supporting a suture and a knife assembly including a knife positioning arm supporting a cutting tool having a knife blade. The knife positioning arm is configured to move the cutting tool from a home position to a cut position along a curved barb cutting path to form a barb in the suture. [0011] In aspects, the barb cutting apparatus further includes an energy assembly including an ultrasonic horn coupled to the knife positioning arm. The cutting tool may be coupled to the ultrasonic horn.

[0012] In aspects, the knife positioning arm includes a mounting linkage including a first end portion operably coupled to the cutting tool and a second end portion operably coupled to a cam such that rotation of the cam moves the cutting tool between the home and cut positions. In some aspects, the cutting tool is fixedly coupled to the first end portion of the mounting linkage. In some aspects, the knife positioning arm further includes a second linkage having a first end portion spaced from the first end portion of the mounting linkage, and the cutting tool is pivotably coupled to the first end portions of the mounting linkage and the second linkage.

[0013] The details of one or more aspects of this disclosure are set forth in the accompanying drawings and the description below. Other aspects, as well as features, objects, and advantages of the aspects described in this disclosure will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Various aspects of this disclosure are described hereinbelow with reference to the drawings, which are incorporated in and constitute a part of this specification, wherein:

[0015] FIG. 1 is a side view of a barbed suture formed in accordance with aspects of this disclosure;

[0016] FIG. 2 is a schematic view of a barb cutting apparatus in accordance with aspects of this disclosure;

[0017] FIGS. 3 A and 3B are schematic view of knife positioning arms suitable for use in the barb cutting apparatus of FIG. 2 in accordance with aspects of this disclosure;

[0018] FIGS. 4A and 4B are schematic views of cutting tools suitable for use in the barb cutting apparatus of FIG. 2 in accordance with aspects of this disclosure; and [0019] FIGS. 5 and 6 are side sectional views of barbed sutures formed in accordance with aspects of this disclosure and illustrate barb cutting paths for forming the barbs on the barbed sutures in accordance with aspects of this disclosure.

DETAILED DESCRIPTION

[0020] Aspects of this disclosure will now be described in detail with reference to the drawing figures wherein like reference numerals identify similar or identical elements. Throughout this description, the term “proximal” refers to a portion or component of a structure that is closer to a user, and the term “distal” refers to a portion or component of the structure that is farther from the user. The terms “about,” “generally,” “substantially,” and the like, shall be understood as words of approximation that take into account relatively little to no variation in the modified terms (e.g., generally accepted manufacturing, use, environmental, or measurement tolerances differing, for example, by less than 10%).

[0021] It should be understood that the disclosed aspects are merely exemplary of the disclosure and may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the disclosure in virtually any appropriately detailed structure.

[0022] FIG. 1 illustrates a barbed suture 10 formed in accordance with a method of this disclosure. The barbed suture 10 includes an elongate body 12 and at least one barb 14 extending from the elongate body 12. The elongate body 12 may be formed from absorbable material(s), non-absorbable material(s), and combinations thereof. The elongate body 12 may be formed using any technique within the purview of those skilled in the art, such as, for example, extrusion, molding, and/or solvent casting.

[0023] While the elongate body 12 is shown as a monofilament suture body, it should be understood that the elongate body 12 may be a multifilament suture body. The elongate body 12 may be a yarn made of multiple filaments of the same or different materials. A multifilament suture body may be formed using any known technique such as, for example, braiding, weaving, or knitting. The filaments may also be combined to produce a non-woven suture. The filaments themselves may be drawn, oriented, crinkled, twisted, commingled, or air entangled to form yarns as part of the suture forming process. Further, while the elongate body 12 is shown having a substantially circular cross-sectional shape, it should be understood that the elongate body 12 may have any suitable or desired shape.

[0024] The barbed suture 10 may include a loop 16 formed at (or attached to) a distal end 12a of the elongate body 12. The loop 16 may be formed and/or attached in any manner within the purview of those skilled in the art prior to or upon completion of the barb forming process and be of any size and configuration. In some aspects, the loop 16 is configured to enhance retention of the barbed suture 10 in body tissue. The barbed suture 10 may include a needle 18 attached to a proximal end 12b of the elongate body 12. The needle 18 may be attached to the elongate body 12 prior to or upon completion of the barb forming process.

[0025] Optionally, the barbed suture 10 may be coated or impregnated with one or more bioactive agents (e.g., to accelerate or beneficially modify the healing process when the barbed suture is applied to a wound or surgical site) and/or additives, such as dyes, pigments, or colorants (e.g., to increase visibility of the barbed suture in the surgical field). The bioactive agents and/or the additives may be applied onto the barbed suture utilizing any method within the purview of those skilled in the art including, for example, dipping, spraying, vapor deposition, brushing, mixing, compounding, and the like.

[0026] In aspects, the at least one barb 14 includes a plurality of barbs 14 extending along at least a portion of the length of the elongate body. As shown, the barbs 14 are disposed in a helical pattern around the elongate body 12. It should be understood, however, that other patterns are envisioned and the pattern of the barbs 14 may be consistent along the length of the elongate body 12 (e.g., be symmetrical) or may vary (e.g., be asymmetrical or random). Further, the barbs 14 are shown formed projecting from the elongate body 12 toward the distal end 12a of the barbed suture 10. It should be understood that the barbs 14 may be formed such that some of the barbs 14 project toward the distal end 12a and the remaining barbs 14 project toward the proximal end 12b so as to form a bi-directional suture. Further still, while the barbs 14 are shown as all being the same, it should be understood that the barbs may be different (single and/or compound, small and/or large, etc.). Accordingly, the barbs 14 may be formed in any number, size, configuration, spacing, and/or orientation depending upon the desired characteristics of the barbed suture 10 for its intended use (e.g., the type of tissue being manipulated and/or the procedure performed), as well as the composition and/or geometry of the material utilized to form the barbed suture 10.

[0027] FIG. 2 illustrates a barb cutting apparatus 100 in accordance with aspects of this disclosure for forming the barbs 14 (FIG. 1) on a barbed suture 10 (also referred to herein generally as a suture in reference to the barbed suture prior to the barbs being formed thereon). The barb cutting apparatus 100 includes a suture retaining assembly 110, a cutting or knife assembly 120, an energy assembly 130, and a visual inspection assembly 140.

[0028] The suture retaining assembly 110 is configured to hold one or more sutures 10 (FIG. 1) in the barb cutting apparatus 100. The suture retaining assembly 110 includes a gripper 112 for supporting the suture in a fixed position. In aspects, the suture retaining assembly 110 includes an advance slide 114 configured to move the suture linearly along an axis that is generally perpendicular to the knife assembly 120. The advance slide 114 moves the suture a predetermined distance or increment after each cut is made to form a barb in the suture for appropriate barb spacing. In some aspects, the suture retaining assembly 110 includes a rotational motor 116 configured to rotate the suture. In certain aspects, the suture retaining assembly 110 includes a motorized slide 118 for moving the suture three-dimensionally (e.g., in X, Y, and Z planes) relative to the knife assembly 120.

[0029] The knife assembly 120 is configured for cutting barbs 14 (FIG. 1) in the elongate body 12 of a suture 10. The knife assembly 120 includes a knife positioning arm 122 secured to and extending from a platform 121 of the knife assembly 120. The knife positioning arm 122 supports a cutting tool 124 having a knife blade 126. In aspects, the knife positioning arm 122 includes one or more arm links 123a interconnected at arm joints 123b. In some aspects, the knife positioning arm 122 may utilize linkages, cams, followers, rollers, or the like that are configured to move the cutting tool 124 three-dimensionally and/or along a barb cutting path, certain aspects of which are provided in greater detail below. It should be understood that the size, shape, and/or configuration of the knife blade 126 may vary depending upon the barb cutting path, as also described in greater detail below, and/or more than one knife blade 126 may be provided on the cutting tool 124. In aspects, the knife assembly 120 includes a knife positioning slide 127 for adjusting the position of the knife blade 126 relative to the suture retaining assembly 110. In aspects, the knife assembly 120 further includes a rotary mechanism 128 for rotating the cutting tool 124 to, for example, adjust the cut angle of a barb.

[0030] The energy assembly 130 is shown as an ultrasonic energy assembly including a horn 132, a converter 134, and an ultrasonic generator 136. The horn 132 is configured and dimensioned to accept the cutting tool 124 for forming barbs on the suture. The converter 134 is operably coupled to the horn 132 and transmits ultrasonic energy to the horn 132. The converter 134 converts electrical energy to mechanical energy which causes displacement of the cutting tool 124 at a predetermined ultrasonic frequency powered by the ultrasonic generator 136. The ultrasonic generator 136 may be manipulated to either increase or decrease the ultrasonic frequency which may be transmitted to the cutting tool 126. Additionally or alternatively, the energy assembly 130 may include a heating element (not shown) or other suitable mechanism for heating the cutting tool 124. By vibrating and/or heating the cutting tool 124, the force necessary to cut barbs into a suture may be reduced.

[0031] While the ultrasonic generator 136 is shown as an individual and discrete unit, it should be understood that the ultrasonic generator 136 may be integrated into a control box (not shown) which is configured to control the functions and operation of the barb cutting apparatus 100.

[0032] The visual inspection assembly 140 includes at least one camera 142 configured for monitoring the cutting of the barbs in the suture and a lighting system 144 configured for optimizing the view of the camera 142. In aspects, the camera 142 records the method of forming barbs. In some aspects, in the event that a mis-formed or defective barb is cut, the visual inspection assembly 140 may be configured to provide an alert to signal that a defect has occurred. In certain aspect, the visual inspection assembly 140 is configured to signal a cutting assembly (not shown) to sever the defective suture.

[0033] FIGS. 3A and 3B illustrate knife positioning arms 122a, 122b, respectively, suitable for use in the barb cutting apparatus 100 (FIG. 2). FIG. 3A shows a knife positioning arm 122a including a mounting plate or linkage 150 pivotably coupled to the platform 121 (FIG. 2) or an arm link 123a (FIG. 2) of the knife assembly 120 about a joint 151 (e.g., a fixed rotation joint). The mounting plate 150 includes a first end portion 150a fixedly coupled to the horn 132 which, in turn, is fixedly coupled to the cutting tool 124, as described above. The mounting plate 150 includes a second end portion 150b configured to maintain contact with an outer surface of a cam 152. In some aspects, the mounting plate 150 may include a cam follower (not explicitly shown) configured to roll over the cam 152. The cam 152 includes a circular base 152a and a nose 152b extending from a portion of the circular base 152a. The cam 152 is configured to rotate (e.g., via a cam actuator) about a joint 153 (e.g., a fixed rotation joint) in the direction of arrow “W.”

[0034] When the cam 152 rotates, the mounting plate 150 and thus, the cutting tool 124 pivots between a first position “A” (shown in phantom) and a second position “C”. In the first position, the second end portion 150b of the mounting plate 150 contacts the circular base 152a of the cam 152 and, in the second position, the second end portion 150b of the mounting plate 150 contacts the nose 152b of the cam 152 such that continuous rotation of the cam 152 provides a back and forth motion of the knife blade 126 along a curved path between the first position “A” and the second position “C” It should be understood that the movement path of the knife blade 126 and/or the distance the knife blade 126 travels may vary depending upon, for example, the shape of the cam 152 and/or the length of the mounting plate 150.

[0035] FIG. 3B shows a knife positioning arm 122b including first and second mounting linkages 160, 164 (also referred to herein generally as first and second linkages) and a cam 162. The first and second linkages 160, 164 are disposed in substantially parallel relationship relative to one other and are each pivotably coupled to the platform 121 (FIG. 2) or an arm link 123a (FIG. 2) of the knife assembly 120 about respective joints 161, 165 (e.g., fixed rotation joints). Each of the first and second linkages 160, 164 includes a first end portion 160a, 164a pivotably coupled to the horn 132 about a joint 167, 169 (e.g., floating joints). The first linkage 160 includes a second end portion 160b configured to maintain contact with an outer surface of the cam 162. In some aspects, the first linkage 160 may include a cam follower (not explicitly shown) configured to roll over the cam 162. The cam 162 includes a circular base 162a and a nose 162b extending from a portion of the circular base 162a. The cam 162 is configured to rotate about a joint 163 (e.g., a fixed rotation joint) in the direction of arrow “W.”

[0036] When the cam 162 rotates, the first linkage 160 pivots about the joint 161 thereby pivoting the horn 132 about the joints 167, 179 and the second linkage 164 about the pivot 165 such that the cutting tool 124 pivots between a first position “A” (shown in phantom) and a second position “C” In the first position, the second end portion 160b of the first linkage 160 contacts the circular base 162a of the cam 162 and, in the second position, the second end portion 160b of the first linkage 160 contacts the nose 162b of the cam 162 such that continuous rotation of the cam 162 provides a back and forth motion of the knife blade 126 along a curved path between the first position “A” and the second position “C”.

[0037] FIGS. 4A and 4B illustrate cutting tools 124a, 124b respectively, suitable for use in the barb cutting apparatus 100 (FIG. 2). FIG. 4A shows a cutting tool 124a including a base or connector 125a configured to be received within the horn 132 (FIG. 2) and a knife blade 126a, in the form of a linear knife blade, extending from the base 125a. A cutting edge 127a of the knife blade 126a is substantially planar along a length of the cutting edge 127a that extends along an axis “Y2” that is substantially parallel to a central longitudinal axis “Yl” of the base 125a. The knife blade 126a is also substantially planar from the cutting edge 127a to a spine 129a of the knife blade 126a that extends along an axis “Zl” that is substantially perpendicular to the central longitudinal axis “Yl” of the base 125a.

[0038] FIG. 4B shows a cutting tool 124b including a base or connector 125b configured to be received within the horn 132 (FIG. 2) and a knife blade 126b, in the form of a curved knife blade, extending from the base 125b. A cutting edge 127b of the knife blade 126b is substantially planar along a length of the cutting edge 127b that extends along an axis “Y4” that is substantially parallel to a central longitudinal axis “Y3” of the base 125b. The knife blade 126b is curved from the cutting edge 127b to a spine 129b of the knife blade 127b along an axis “Z2” that is substantially perpendicular to the central longitudinal axis “Y3” of the base 125b. It should be understood that the length and/or shape of the knife blades 126a, 126b may vary depending upon the barb cutting path, the desired cut depth, desired cut angle, etc. of the knife blade 126a, 126b into the suture.

[0039] Referring again to FIG. 2, in operation, a suture (not explicitly shown) is secured to the suture retaining assembly 110 and the visual inspection assembly 140 is activated. The suture retaining assembly 110 and the knife assembly 120 are positioned relative to each other such that the knife blade 126 of the cutting tool 124 is positioned in close proximity to (but not in contact with) the suture (e.g., via the knife positioning slide 127). The energy assembly 130 is then activated to cause the ultrasonic vibrating or heating of the cutting tool 124. Once the energy assembly 130 has been activated, barbs are formed on the suture by moving the cutting tool 124 relative to the suture. In aspects, the knife blade 126 is brought into contact with the suture (e.g., via the knife positioning arms 122) while the suture remains in a stationary or fixed position during the barb forming or cutting process. In some aspects, the suture is moved (e.g., via the advance slide 114 and/or rotational motor 116) between each of the barb cuts. In some other aspects, the knife blade 126 is moved (e.g., via the knife positioning arm 122 and/or the rotary mechanism 128) between each of the barb cuts.

[0040] Alternatively, the barbs may be formed on the suture by movement of the suture retaining assembly 110 relative to the knife assembly 120. In this manner, the suture is moved into contact with the knife blade 126 of the cutting tool 124 (e.g., via the motorized slide 118) while the cutting tool 124 remains in a stationary or fixed position during the barb forming process.

[0041] A barb is formed in the suture by moving the knife blade 126 along a predetermine barb cutting path and using ultrasonic energy at various frequencies and signal amplitudes to cut the elongate body of the suture to form a barb having a predetermined geometry. The barb cutting path is a curved or arced path into the suture that forms a barb in one step (e.g., by a single continuous cut).

[0042] FIG. 5 illustrates a barb cutting path “B” for the knife blade 126 (FIG. 2) of the barb cutting apparatus 10 into an elongate body 12 of a suture 10 to form a barb 14 in accordance with an aspect of this disclosure. The knife blade 126 may be, for example, the knife blades 126a, 126b shown in respective FIGS. 4A and 4B. The barb cutting path “B” is shown as an arc of an ellipse (e.g., a segment of the perimeter of the ellipse). In aspects, the knife positioning arm 122 (FIG. 2) is configured to move the knife blade 126 along the barb cutting path “B” to cut the barb 14 into the elongate body 12 of the suture 10. The knife positioning arm 122 may be moved along the barb cutting path “B” via, for example, the knife positioning arms 122a, 122b shown in respective FIGS. 3A and 3B.

[0043] The knife blade 126 (FIG. 2) is moved from the first or home position “A”, which is adjacent to, but not in contact with, the elongate body 12 of the suture 10, along the barb cutting path “B” to the second or cut position “C”, which is the furthest distance into the elongate body 12 of the suture. 10. In aspects, the depth “d” of the barb 14 is the greatest at (or about) the cut position “C” (e.g., where the barb 14 meets the elongate body 12). The knife blade 126 may contact the elongate body 12 at an angle to form the barb 14. In aspects in which the knife blade 126 is linear, the motion of the knife blade 126 is arced to follow the barb cutting path “B” from the home position “A” to the cut position “C”. In aspects in which the knife blade 126 is curved, the motion of the knife blade 126 may be arced or may be linear depending upon, for example, the curvature of the knife blade 126.

[0044] After the barb cut is made, the knife blade 126 (FIG. 2) returns to the home position “A” by traveling back through the barb cutting path “B” from the cut position “C”. Alternatively, the knife blade 126 may return to the home position “A” by traveling through the remainder of the ellipse along path “D” (shown in phantom). In aspects in which the knife blade 126 does a full elliptical rotation, the suture 10 is advanced out of the way of the knife blade 126 after the knife blade 126 reaches the cut position “C”. During the barb cut, the knife blade 126 engages the inner surface 14a of the barb 14 and thus, flexes the barb 14 outwardly away from the elongate body 12. The barb 14 is flexed at an angle “e” that is obtuse with respect to an outer surface 12c of the elongate body 12.

[0045] The inner surface 14a of the barb 14 has a non-linear configuration. The inner surface 14a defines a first or outer portion 15a and a second or inner portion 15b. The first portion 15a of the barb 14 is formed in the suture 10 by the knife blade 126 (FIG. 2) initially traveling along an arc of the ellipse that extends to about a co-vertex of the ellipse and the second portion 15b of the barb 14 is formed in the suture 10 by the knife blade 126 traveling from the co-vertex to about a vertex of the ellipse. The first portion 15a of the barb 14 is generally disposed at a first orientation relative to a central longitudinal axis “X” of the barbed suture 10 and the second portion 15b is generally disposed at a second orientation relative to the central longitudinal axis “X’. The first and second portions 15a, 15b are generally arcuate in shape, however, it is envisioned that the first and/or second portion 15a, 15b may be generally linear depending upon the shape of the arc of the barb cutting path “B” In aspects, the first and second portions 15a, 15b define respective first and second angles “a”, “b” (e.g., measured along tangents of the first and second portions 15a, 15b). In aspects, the first angle “a” is greater than the second angle “b”.

[0046] Additional barbs 14 are formed in the manner described above. The process continues until the barbs 14 are formed along the desired length of the elongate body 12 of the suture 10. The barbed suture 10 is then unloaded from the barb cutting apparatus 10 as the barb forming process is complete. [0047] It should be appreciated that the barb cutting path may follow other arcs of an ellipse and/or the ellipse may have different shapes and/or sizes. For example, as shown in FIG. 6, a suture 10’ includes barbs 14’ formed in the elongate body 12’ by the knife blade 126 (FIG. 2) following a barb cutting path “Bl” that is an arc of a circle.

[0048] While this disclosure describes devices and methods of forming barbs on sutures, it should be understood that barbs may be formed on other medical devices such as, for example, surgical fibers, anchors, slit sheets, ribbons, tapes, meshes, stents, scaffolds, pledgets, and vascular grafts.

[0049] While aspects of the disclosure have been shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. It is to be understood, therefore, that the disclosure is not limited to the precise aspects described, and that various other changes and modifications may be made by one skilled in the art without departing from the scope or spirit of the disclosure. Additionally, the elements and features shown and described in connection with certain aspects of the disclosure may be combined with the elements and features of certain other aspects without departing from the scope of the present disclosure, and that such modifications and variation are also included within the scope of the present disclosure. Therefore, the above description should not be construed as limiting, but merely as exemplifications of aspects of the disclosure. Thus, the scope of the disclosure should be determined by the appended claims and their legal equivalents, rather than by the examples given.

Claims

WHAT IS CLAIMED IS:

1. A method of forming barbs on a suture, the method comprising: contacting a first portion of an outer surface of an elongate body of a suture with a cutting tool of a barb cutting apparatus; and passing the cutting tool into the suture along a curved barb cutting path to form a barb in the elongate body of the suture.

2. The method according to claim 1 , further comprising applying ultrasonic energy to the cutting tool.

3. The method according to claim 1, wherein passing the cutting tool into the suture further includes forming a cut in the elongate body having a generally concave shape.

4. The method according to claim 1 , wherein the curved barb cutting path is an arc of an ellipse.

5. The method according to claim 1, wherein the curved barb cutting path is an arc of a circle.

6. The method according to claim 1, wherein passing the cutting tool into the suture includes moving the cutting tool into the suture.

7. The method according to claim 1, wherein passing the cutting tool into the suture further includes moving the cutting tool from a home position spaced from the suture to a cut position disposed within the suture.

8. The method according to claim 7, wherein a depth of the barb is greatest at the cut position.

9. The method according to claim 7, further comprising moving the cutting tool back to the home position after forming the barb.

10. The method according to claim 9, wherein moving the cutting tool back to the home position includes moving the cutting tool along the curved barb cutting path from the cut position to the home position.

11. The method according to claim 9, wherein moving the cutting tool back to the home position includes moving the cutting tool through a full elliptical rotation.

12. The method according to claim 11, further comprising moving the suture after moving the cutting tool from the home position to the cut position.

13. The method according to claim 1, wherein the cutting tool includes a linear knife blade and passing the cutting tool into the suture further includes moving the linear knife blade through an arc that follows the curved barb cutting path.

14. The method according to claim 1, wherein the cutting tool includes a curved knife blade.

15. The method according to claim 14, wherein passing the cutting tool into the suture includes moving the curved knife blade linearly into the elongate body.

16. A barb cutting apparatus, comprising: a suture retaining assembly including a gripper for supporting a suture; and a knife assembly including a knife positioning arm supporting a cutting tool having a knife blade, the knife positioning arm configured to move the cutting tool from a home position to a cut position along a curved barb cutting path to form a barb in the suture.

17. The barb cutting apparatus according to claim 16, further comprising an energy assembly including an ultrasonic horn coupled to the knife positioning arm, and the cutting tool is coupled to the ultrasonic horn.

18. The barb cutting apparatus according to claim 16, wherein the knife positioning arm includes a mounting linkage including a first end portion operably coupled to the cutting tool and a second end portion operably coupled to a cam such that rotation of the cam moves the cutting tool between the home and cut positions.

19. The barb cutting apparatus according to claim 18, wherein the cutting tool is fixedly coupled to the first end portion of the mounting linkage.

20. The barb cutting apparatus according to claim 18, wherein the knife positioning arm further includes a second linkage having a first end portion spaced from the first end portion of the mounting linkage, and the cutting tool is pivotably coupled to the first end portions of the mounting linkage and the second linkage.