Patent Abstract:
An apparatus for forming an end effector includes a welding device having a welder positioned adjacent to a base, and a die coupled to one end of the welder. The base and the welder are movable relative to each other. The welder, base or die includes a source of heat that is applied to a portion of the suture disposed between the welder and the base.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. application Ser. No. 12/888,652 filed Sep. 23, 2010 (now U.S. Pat. No. 8,297,330), which claims the benefit of and priority to U.S. Provisional Patent Application Ser. No. 61/247,702, filed Oct. 1, 2009, the disclosure of which is herein incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to sutures for use in medical procedures. More particularly, the present disclosure relates to a welded knot end effector. 
     2. Background of Related Art 
     Medical sutures may be formed from a variety of materials and may be configured for use in limitless applications. The proximal end of the suture may have a sharpened tip, or may include a needle, for penetrating tissue. A distal end of the suture may include an anchor or end effector for maintaining the suture in engagement with the tissue as the suture is pulled through the tissue. End effectors are available in many size and configurations. 
     In many instances, a clinician may prefer to tie a knot in the suture to anchor the suture within the tissue. Although the clinician may find this practice convenient, the knot formed on the end of the tissue is not always suitable to prevent the suture from being pulled through the tissue, for example, the knot slips or is too small to engage the tissue. Additionally, the tying of a knot, especially with the fine suture material required for use in many procedures, is tedious and time consuming. 
     Therefore, a continuing need exists for an end effector and a method of making an end effector. 
     SUMMARY 
     A method of forming a welded end effector is presently disclosed. The method includes providing a length of suture including a knot and a welding device selectively engagable with the knot, the welding device includes a base and a welder. Additionally the method includes positioning a portion of the suture within a welding device, activating the welding device and reducing the gap between the welder and the base to weld the knot. Activating the welding device may include activating contact heating, radiant heating or ultrasonic welding. The gap between the welding device and the base may be from 0.001 inches to 0.05 inches. The knot may include a first section and a second section, each of the first and second sections including a plurality of throws. 
     Also disclosed is a welding device for forming a welded end effector. The welding device includes a base and a welder positioned adjacent to the base. The welder may include a die extending towards the base. The welder is capable of relative movement with respect to the base. The die may be made of titanium. The base may include grooves to form a raised portion on the welded end effector to enhance engagement of the welded end effector with a tissue. The welding device is configured to retain a distal end of a suture between the die and the base. 
     Further disclosed is a system for forming an end effector. The system includes a suture and a welding device. The suture may include a body portion defining a longitudinal axis and a knot integrally formed from the body portion. The welding device may include a welding device having a die coupled to one end of the welder and a base supporting at least a portion of the suture and a welder positioned adjacent to the base and movable relative to the base. Relative movement of the welder and the base compresses the knot disposed therebetween. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with a general description of the disclosure given above, and the detailed description of the embodiment(s) given below, serve to explain the principles of the disclosure, wherein: 
         FIG. 1  is a side view of an end effector according to an embodiment of the present disclosure; 
         FIG. 2  is a top view of the end effector of  FIG. 1 ; 
         FIG. 3  is a perspective view of the end effector of  FIGS. 1 and 2  prior to being welded; 
         FIG. 4  is a end effector welding device according to an embodiment of the present disclosure; 
         FIG. 5  is the end effector welding device of  FIG. 4 , during the welding of an end effector; 
         FIG. 6  is a top view of a base for the end effector welding device of  FIGS. 4 and 5 ; 
         FIG. 7  is a top view of an alternate base of the end effector welding device of  FIGS. 4 and 5 ; 
         FIG. 7A  is a partial cross-sectional side view of the base of  FIG. 7  taken along lines  7 A- 7 A of  FIG. 7 ; 
         FIG. 8  is a bottom view of a forming die for the end effector welding device of  FIGS. 4 and 5 ; 
         FIG. 8A  is a cross-sectional side view of the forming die of  FIG. 8 ; 
         FIG. 9  is a bottom view of a forming die for the end effector welding device of  FIGS. 4 and 5 ; 
         FIG. 9A  is a cross-sectional side view of the forming die of  FIG. 9 ; 
         FIG. 10  is a bottom view of a forming die for the end effector welding device of  FIGS. 4 and 5 ; 
         FIG. 10A  is a cross-sectional side view of the forming die of  FIG. 10 ; 
         FIG. 11  is an alternate embodiment of an end effector according to the present disclosure, prior to being welded; and 
         FIG. 12  is a side view of an alternative embodiment of an end effector after welding according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Referring initially to  FIGS. 1 and 2 , an embodiment of an end effector according to the present disclosure is shown generally as welded end effector  10 . Although, as shown, end effector  10  if formed on a first end  12   a  of suture  12 , end effector  10  may be formed anywhere along the length of suture  12 . Suture  12  may be formed of degradable materials, non-degradable materials, and combinations thereof. More particularly, suture  12  may be formed of a degradable material selected from the group consisting of polyesters, polyorthoesters, polymer drugs, polydroxybutyrates, lactones, proteins, cat gut, collagens, carbonates, homopolymers thereof, copolymers thereof, and combinations thereof. In other embodiments, suitable degradable materials which may be utilized to form suture  12  include natural collagenous materials or synthetic resins including those derived from alkylene carbonates such as trimethylene carbonate, tetramethylene carbonate, and the like; caprolactone; dioxanone; glycolic acid; lactic acid; homopolymers thereof; copolymers thereof; and combinations thereof. In some embodiments, glycolide and lactide based polyesters, especially copolymers of glycolide and lactide, may be utilized to form suture  12 . 
     Suitable non-degradable materials which may be utilized to form suture  12  include polyolefins, such as polyethylene and polypropylene; copolymers of polyethylene and polypropylene, and blends of polyethylene and polypropylene; polyamides (such as nylon); polyamines; polyimines; polyesters such as polyethylene terephthalate; polytetrafluoroethylene; polyether-esters such as polybutester; polytetramethylene ether glycol; 1,4-butanediol; polyurethanes; and combinations thereof. Other suitable non-degradable materials include silk, cotton, linen, carbon fibers, and the like. The polypropylene may be isotactic polypropylene or a mixture of isotactic and syndiotactic or atactic polypropylene. 
     Suture  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. In some embodiments, suture  12  may include a yarn made of more than one filament, which may contain multiple filaments of the same or different materials. Where suture  12  is made of multiple filaments, suture  12  may be made using any known technique such as, for example, braiding, weaving or knitting. Suture  12  may also be combined to produce a non-woven suture. Suture  12  may be drawn, oriented, crinkled, twisted, commingled or air entangled to form yarns as part of the suture forming process. In one embodiment, a multifilament suture may be produced by braiding. The braiding may be done by any method within the purview of those skilled in the art. 
     With reference still to  FIGS. 1 and 2 , welded end effector  10  is configured to prevent complete reception of suture  12  through tissue or other material. End effector  10  forms a flattened, substantially disk-shaped member  14  on a first portion  12   a  of suture  12 . End effector  10  defines a horizontal axis “y” formed perpendicular to a longitudinal axis “x” of suture  12 . As will be discussed in greater detail below, configuration of the disk  14  depends on the size and configuration of end effector  10  prior to welding and on the pressure applied by the welding device  150  shown in  FIG. 4 . 
     Turning now to  FIG. 3 , end effector  10  is shown in a pre-welded form. Pre-welded end effector  10   a  forms a knot several times thicker than suture  12  on distal portion  12   a  of suture  12 . Pre-welded end effector  10   a  includes first and second sections  20 ,  30 . Each of first and second sections  20 ,  30  is formed form a plurality of throws  22   a - c ,  32   a - c , respectively. As used herein, a throw is defined as an at least three-hundred and sixty degree)(360° wrapping or weaving of two limbs. As shown, first and second sections  20 ,  30  each include three throws  22   a - c ,  32   a - c . It is envisioned, however, that first and second sections  20 ,  30  may include any number of throws  22 ,  32 . It is further envisioned that the number of throws on first section  20  need not be equal to the number of throws on second section  30 . A second end  12   b  of suture  12  may include one or more needles (not shown). Suture  12  may include one or more barbs along the length thereof. 
     For a more detailed discussion of pre-welded end effector  10   a , including methods of making the same, please refer to commonly owned U.S. patent application Ser. No. 12/852,672, filed concurrently herewith, the content of which is incorporated herein by reference in its entirety. 
     Turning now to  FIGS. 4 and 5 , an apparatus for forming welded end effector  10  is shown generally as welding device  150 . Although discussed with reference to welding end effector  10 , welding device  150  may be modified to weld end effectors of various shapes and sizes. Welding device  150  includes a base or nest  160  for maintaining suture  12  during the forming of end effector  10  and a welder  170  for forming end effector  10 . Although throughout the remainder of the discussion reference will be made to welder  170  as being of the ultrasonic variety, it is envisioned that welder  170  may include any device capable of causing pre-formed end effector  10   a  to become formable (i.e., other energy sources, heat, light, etc.). It is also envisioned that the source of heat or energy may be in the base  160  or the welder  170 , or both. 
     With continued reference to  FIGS. 4 and 5 , base  160  of welding apparatus  150  includes a substantially flat working surface  162  and an opening  164  extending therethrough. Opening  164  may include a slot  164   a , as shown in  FIG. 6 , or may instead including a throughbore  164   b , as shown in  FIG. 7 . Opening  164  is configured to receive a second end  12   b  of suture  12  therethrough. The size of opening  164  may be varied depending on the size of suture  12 . In one embodiment, opening  164  is no greater than two-thousandths of an inch (0.002″) larger than the diameter of suture  12 . 
     Still referring to  FIGS. 4 and 5 , welder  170  includes a die  172  for forming end effector  10 . Welder  170  may include a device capable of ultrasonically vibrating die  172 . For example, welder  170  may include a Branson 20 KHz ultrasonic welder. Die  172  may be formed of titanium or other suitable material. Die  172  includes a contact surface  174  for engaging end effector  10   a . Contact surface  174  may be substantially flat, or instead contact surface  174  may include recess  174   a  ( FIGS. 8A and 9A ) and/or raised portion  174   b  ( FIG. 10A ). Recess(es)  174   a  may be rectangular ( FIG. 8 ), circular, oval ( FIG. 9 ) or any other configuration. Recess(es)  174   a  are configured to form a raised or contoured portion(s) (not shown) in a top surface of end effector  10  during the welding process. Raised surface(s)  174   b  is configured to form a recess(es) (not shown) in the top surface of end effector  10 . The raised surface(s) and/or recess(es) (not shown) formed in the top surface of end effector  10  may be configured to enhance tissue engagement of end effector  10  and/or to facilitate grasping of end effector  10 . Welder  170  may weld the end effector  10  by any means designed to soften pre-welded end effector  10   a , for example by applying contact heating, radiant heating or ultrasonic. It is envisioned that base  160  of welding apparatus  150  may include an ultrasonic mechanism (not shown) for ultrasonically vibrating base  160  during the forming of end effector  10 . In particular, welder  170  includes a source of heat or energy as known in the art. It is envisioned that the source of heat or energy source may be located in the welder, the die, the base, or combinations thereof. The heat source may be an ultrasonic heat source, a radiant heat source, or a contact heat source. 
     Turning to  FIG. 7 , in one embodiment, working surface  162  of base  160  includes grooves or indents  165  formed about opening  164 . During welding of end effector  10 , grooves  165  form raised portions (not shown) in a bottom surface of end effector  10 . Alternatively, working surface  162  may include one or more raised surfaces (not shown) for forming one or more recess in the bottom surface of end effector  10  during welding of end effector  10 . The ridges and/or recess may be configured to enhance tissue engagement of end effector  10  and/or to facilitate grasping of end effector  10 . 
     With reference again to  FIGS. 4 and 5 , the operation of welding device  150  will be described. Initially, a pre-welded end effector  10   a  is formed in first end  12   a  of suture  12  and any excess material is trimmed away. Pre-welded end effector  10   a  may be formed on site or instead be provided on suture  12 . Second end  12   b  of suture  12  is then received through opening  164  of base  160  such that pre-welded end effector  10   a  is received on working surface  162  of base  160  adjacent to ultrasonic welder  170 . 
     When using an ultrasonic heating source, welder  170  is then activated to vibrate die  172 . Die  172  is then brought into contact with pre-welded end effector  10   a  to form end effector  10 . In one embodiment, welder  170  is configured to be approximated towards base  160 . In another embodiment, base  160  is configured to be approximated towards welder  170 . In yet another embodiment, both base  160  and welder  170  are configured to be approximated towards one another. Regardless of whether base  160  and/or welder  170  is approximated, approximation between base  160  and welder  170  occurs until a gap “G” is formed between working surface  162  of base  160  and contact surface  174  of die  172 . The distance of gap “G” is dependent on the thickness of suture  12 , the size of pre-welded end effector  10   a  and/or the desired diameter of resulting end effector  10 . In one embodiment, gap “G” ranged from one-thousandth of an inch (0.001″) to five-hundredths of an inch (0.05″). 
     Still referring to  FIGS. 4 and 5 , when using an ultrasonic energy source contacting pre-welded end effector  10   a  with contact surface of vibrating die  172  causes pre-welded end effector  10   a  to soften or melt. In one embodiment, the welding parameters range from half of a joule (0.5 J) to sixty joules (60 J) and includes a minimum hold time of a quarter of a second (0.25 s). Base  160  and/or welder  170  are moved away from each other and suture  12  including end effector  10  is removed from opening  164  formed in base  160 . Welding of pre-welded end effector  10   a  prevents unraveling of the end effector during use. Welding of pre-welded end effector  10   a  also increases the surface of end effector  10   a  that comes into contact with tissue forming disk  14  ( FIG. 1 ), thereby distributing load force more effectively, allowing for a greater load to be exerted before failure of either the tissue or end effector  10 . 
     With reference to  FIG. 11 , another embodiment of an end effector capable of use with welding device  150  prior to being welded is shown generally as pre-welded end effector  210   a . Pre-welded end effector  210   a  forms a substantially T-shaped knot formed on first end  212   a  of suture  212 . Pre-welded end effector  210   a  defines an axis “Y” extending perpendicular to a longitudinal axis “X” of suture  212 . Pre-welded end effector  210   a  includes first and second extensions  220 ,  230  extending perpendicularly with respect to axis x from suture  212  in opposite directions along axis “Y” to form a T-shape. Each of first and second extension  220 ,  230  is formed from a plurality of throws  222   a - c ,  232   a - c , respectively, thereby forming undulated members. As shown, first and second extensions  220 ,  230  each include three throws  222   a - c ,  232   a - c . It is envisioned, however, that first and second extensions  220 ,  230  may include any number of throws  222 ,  232 . It is further envisioned that the number of throws on first extension  220  need not be equal to the number of throws on second extension  230 . A second end  212   b  of suture  212  may include one or more needles (not shown) and/or may include one or more barbs. Pre-welded end effector  210   a  may be welded in the same manner as described above with regards to pre-welded end effector  10   a  to form end effector  210  ( FIG. 12 ). 
     Although the illustrative embodiments of the present disclosure have been described herein with reference to the accompanying drawings, it is to be understood that the disclosure is not limited to those precise embodiments, and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the disclosure.

Technology Classification (CPC): 1