Abstract:
An obturator assembly having a removable obturator tip, a first engagement device, an obturator shaft, a second engagement device, and a biased flexible member, whereby the obturator tip may be removed by flexing the flexible member against its bias, and a plurality of different obturator tips may be attached to the obturator shaft.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. Ser. No. 09/060,640, now U.S. Pat. No. 6,106,539 filed Apr. 15, 1998. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     This invention relates to an obturator having a removable, replaceable tip and more particularly to such a removable, replaceable tip that flexibly engages and releases the obturator tip from the shaft. 
     2. Description of the Prior Art 
     Conventional trocars use an obturator with a sharp metal tip to penetrate a body cavity in surgical procedures. After each use, the obturator must be sterilized and eventually the tip dulls and must be re-sharpened by machining. These obturators are expensive and adding to their effective cost is the cost of sharpening, sterilizing and the loss of use during those procedures. Some trocars are made to be disposable, i.e., they are used once and discarded with no need for resharpening or sterilizing. Their initial cost is, however, quite high. Alternatively, some trocar obturators are made with a removable metal tip. During the course of surgery, these obturators will often have to be changed to conform to the particular demands of that surgical procedure. However, these tips are also expensive and must be regularly sterilized and periodically re-sharpened. Moreover, obturator shafts tend to be sold without a cutting tip. The tips are sold individually, which requires the surgeon or hospital to maintain a complex and diverse inventory. 
     SUMMARY OF THE INVENTION 
     The obturator assembly of the present invention may comprise: a removable obturator tip having a sharpened distal end and a proximal end; a first engagement device disposed on the proximal end of the removable obturator tip; an obturator shaft having a distal end; a second engagement device disposed on the distal end of the obturator shaft adapted to lockingly engage the first engagement device, thereby securing the removable obturator tip to the obturator shaft; and a biased flexible member adapted to flexibly engage the first engagement device to the second engagement device, the flexible member being accessible whereby the flexible member can be flexed against its bias to disengage the first engagement device from the second engagement device. 
     In specific embodiments of the present invention, the sharpened distal end of the obturator tip: (a) may have a serrated cutting edge; (b) may have a piercing cutting edge; (c) may have a blunt cutting edge; (d) may have a radial cutting edge; (e) may have a cutting edge that cuts and dilates in two directions; (f) may make an incision that is linear and easy to close; (g) may have a semi-circular cutting edge; (i) may have a double beveled cutting edge; (j) may have a claw shaped cutting edge; (k) may create an incision that allows the obturator tip to be rotated as the incision is made; (l) may have a triangular cutting edge; (m) may have a hooked blade cutting edge; (n) may have a sickle shaped cutting edge; (o) may have a flat cutting edge. 
     The obturator assembly of the present invention may also comprise: a removable obturator tip having a sharpened distal end and a proximal end; a biased flexible leg extending from the proximal end of the tip, the flexible leg having a detent; an obturator shaft having a stop, the stop being adapted to engage the detent on the biased flexible leg, thereby connecting the tip to the obturator shaft; and an access port disposed on the obturator shaft, whereby the flexible leg can be moved against its bias to disengage the detent from the stop. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings: 
     FIG. 1 is a three-dimensional view of an obturator assembly including a removable replaceable tip according to this invention; 
     FIG. 2 is an enlarged detail view of the obturator tip of FIG. 1; 
     FIG. 2A is a cross-sectional view taken along lines  2 A— 2 A of FIG. 2 showing a groove that has a circular shape; 
     FIG. 2B is a view similar to FIG. 2A in which the groove has a polygonal shape; 
     FIG. 2C is a view similar to FIGS. 2A and 2B wherein the groove has a square shape; 
     FIG. 3 is an enlarged detailed plan view of the obturator shaft of FIG. 1; 
     FIG. 4 is an enlarged detailed elevational view of the obturator shaft of FIG. 1; 
     FIG. 5 is a view similar to FIG. 2 wherein there is but one flexible leg, one detent and one access hole; 
     FIG. 6 is a three-dimensional view of the tip of FIG. 5 showing an asymmetric slot in the shaft for definitively orienting the tip and shaft assembly; 
     FIG. 7 is an enlarged detailed side elevational view of another embodiment of the removable replaceable tip according to this invention employing two flexible legs with detents for mating with internal stop shoulders on the shaft; 
     FIG. 8 is a view similar to FIG. 7 of another embodiment of the removable replaceable tip according to this invention in which flexible legs with detents are on the shaft and the tip contains access ports a portion of which function as stop recesses; 
     FIG. 9 is a view similar to FIG. 2 in which the alignment means have the salient portion on the tip and the mating recess portion on the shaft; 
     FIG. 10 is a view similar to FIG. 9 of another embodiment of the removable replaceable tip of this invention in which the stop means includes a stop recess separate from the access port; 
     FIG. 11 is a view similar to FIG. 9 of another embodiment of the removable replaceable tip of this invention in which the detent is borne by a flexible leg interconnected with a resilient actuator tab on the shaft and the stop recess is a circumferential groove on the tip; 
     FIGS. 12 a-p  are top views of various obturator tips according to this invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows an obturator assembly  10  according to this invention. The obturator assembly  10  may preferably include an obturator tip  12  and shaft  14  with a longitudinal axis  15 . Tip  12  may include a sharpened distal end  16  and a removal groove  18  for receiving, for example, forceps, to remove tip  12  from shaft  14 . Referring to FIGS. 1,  2 ,  3  and  4 , it can be seen that there are engagement means  20  which generally include an engagement device  22  on tip  12  which may be comprised of a pair of flexible legs  24 ,  26  having detents  28  and  30 . There may also an engagement device  32  on shaft  14  which may include the stop means formed by the stop recesses  34  and  36  that can form a part of the oval ports  38  and  40  that preferably constitute the access means by which the fingers of a surgeon can reach and squeeze legs  24  and  26  to move detents  28  and  30  out of contact with stop recesses  34  and  36  in order to release tip  12  from shaft  14 . Flexible legs  24  and  26  preferably have a sufficient bias to maintain detents  28  and  30  in contact with stop recesses  34  and  36 . The bias of flexible legs  24  and  26  is preferably sufficient to provide a snap fit. This snap fit may cause there to be a clicking noise when tip  12  is inserted and seated properly in shaft  14 . In this manner, a surgeon may have an audible confirmation that the shaft and tip are locked together. 
     In order to compel the tip  12  to be inserted in shaft  14  so that legs  24  and  26  align with access ports  38  and  40 , alignment means  42  may be provided, generally consisting of tabs  44  and  46  extending saliently from shaft  14 . Further, recesses  48  and  50  on tip  12  may also be provided. A handle or hub  60  is usually provided on the proximal end of shaft  14  and may be used to apply pressure to push the sharp end  16  of tip  12  through the body tissue. Shaft  14  is preferably hollow, at least at its distal end to provide for access ports  38  and  40  and permit the legs  24  and  26  of tip  12  to be inserted. To provide for strength, sharp cutting edges and the snap fitting action and sound, the trocar may be made of a metal or of a plastic such as of polycarbonate, ABS, polysulfone. 
     Visual indicia may be provided in the form of a contrasting color or texture or pattern  70 , FIG. 2, which may be covered by cover portion  72 , FIGS. 3 and 4, of shaft  14  when tip  12  is properly secured in shaft  14 . In this manner, a surgeon may have another confirmation that the obturator is properly and safely assembled. 
     In operation, tip  12  is generally inserted in shaft  14  by simply pressing the ends of legs  24  and  26  against the cover portion  72  of shaft  14 . Legs  24  and  26 , being flexible, normally flex inward so that detents  28  and  30  may pass under the cover portion, preferably springing out in ports  38  and  40  (in some situations, making a clicking sound when detents  28  and  30  spring into position at stop recesses  34  and  36 ). At this point the color band  70  may no longer be visible as it is preferably hidden by the cover portion  72 . When the surgical procedure is finished and it is desired to remove tip  12 , tip  12  can be gripped by fingers or by a tool such as a forceps which may engage with groove  18  and then the surgeon may place a thumb and forefinger over access ports  38  and  40 , depressing legs  24  and  26  so that detents  28  and  30  disengage from stop recesses  34  and  36 . 
     Groove  18  may have a circular shape or circumference as shown in FIG. 2A, but it may as well have a polygonal shape such as hexagonal shape  18   a,  FIG. 2B, or square shape  18   b,  FIG. 2C, to better receive a wrench-like conformation or forceps. 
     Although in FIGS. 1-4, tip  12  is shown with a pair of flexible legs with detents and a pair of access ports as well as a pair of alignment tabs, these are not necessary limitations of the invention. As shown in FIG. 5, tip  12   a  may include a single recess  50   a  to receive a single salient tab  46   a.  Obturator tip  12   a  may have but a single flexible leg  24   a  with detent  28   a ; accessible through a single port  38   a.  All tabs  46  and recesses  50   a  used for alignment purposes may be eliminated, for example, and replaced by an alignment slot  80 , FIG. 6, which may be asymmetrical and conformed to receive the asymmetrical shaped legs  24   b  and  78   b  so that the tip  12   b  can be automatically properly aligned with shaft  14   b.  Referring again to FIG. 5, element  78  which may take any particular form including a shape similar to leg  24   a  may be provided to keep tip  12   a  trued up and properly oriented in shaft  14   a.    
     While the stop means thus far have been shown as a part of access ports  38  and  40 , this is not a necessary limitation of the invention as they may in fact be constructed as internal stop shoulders  34   c,    36   c,  FIG. 7, which may engage detents  28   c  and  30   c  on legs  24   c  and  26   c.    
     In addition, although thus far the flexible leg or legs and detents have been shown as a part of the tip and the access ports and stops means have been shown as a part of the shaft, this is not a necessary limitation of the invention as the converse is also contemplated by this invention as shown in FIG. 8, where tip  12   d  may include access ports  38   d  and  40   d  having stop recesses  34   d  and  36   d  while shaft  14   d  may contain flexible legs  24   d  and  26   d  having detents  28   d  and  30   d.  In addition, although the alignment means have been shown with the salient tab on the shaft and the recess on the tip, this is not a necessary limitation of the invention, for as shown in FIG. 9, one or more salient tabs  42   e  may be provided on tip  12   e  to self-center and nest in one or more recesses  50   e.    
     The access port or ports for reaching flexible legs and compressing them inwardly against their bias may not provide a recessed stop as a part of its configuration. Rather, as show in FIG. 10, where tip  12   f  is shown as having been rotated 90 degrees with respect to shaft  14   f,  the stop recess  36   f  may be independently provided to engage detent  28   f  on leg  24   f  and a similar stop recess, not shown, may be provided on the opposite side of shaft  14   f.  Note that the assembly in FIG. 10 has been shown in an orientation to provide the best visualization of the specific embodiment shown, therefore, in FIG. 10, for proper rotational orientation of the tip  12   f  and shaft  14   f,  tip  12   f  must be rotated so that leg  24   f  comes out of the paper and leg  26   f  rotates into the paper about the central longitudinal axis  15   f  so that detent  24   f  fits into stop recess  36   f.    
     Although the access means has been shown as one or more ports, this is not a necessary limitation of the invention, For example, as shown in GIF  11 , flexible leg  24   g,  having internally extending detent  28   g,  may be flexibly interconnected at junction  100 , FIG. 11, with access actuator tab  38   g  in opening  38   gg  so that a downward pressure on tab  38   g  rocks leg  24   g  upwardly, lifting detent  28   g  out of stop recess hole  34   g.  A similar construction may be duplicated on the opposite side of tip  12   g  and shaft  14   g.  Hole  34   g  may be replaced by a circumferential slot  34   gg  so that orientation is not a problem as detent  28   g  and a complementary one on the other side of shaft  14   g  can engage anywhere along groove  34   gg.    
     FIGS. 12 a - 12   p  show an assortment of obturator tips that can be used on the obturator of this invention. The tips shown have a variety of cutting edges that may enable the surgeon to perform various intricate surgical procedures. Some of the cutting edges of the obturator tips shown in FIGS. 12 a - 12   p  include serrated cutting edges (i.e. FIGS. 12 j  and  12   p,  piercing cutting edges (i.e. FIGS. 12 d  and  12   i,  blunt cutting edges (i.e. FIG. 12 o  and radial cutting edges (i.e. FIGS. 12 a,    12   g  and  12   h ). 
     FIG. 12 a  shows a disc obturator tip  109  that preferably cuts and dilates in two directions and may provide an incision that is linear and easy to close. FIG. 12 b  shows a semi-circle obturator tip  110  which preferably cuts and dilates in two directions, provides a linear incision which is easy to close, and penetrates along two points  112  and  114 . FIG. 12 c  shows a sword obturator tip  116  which may cut and dilate in two directions, may provide an incision which is linear and easy to close and may provide easy penetration with its double beveled  118  and pointed tip  120 . FIG. 12 d  shows a claw obturator tip  122  which preferably cuts and dilates in two directions, provides an incision which is linear and easy to close, and may have a piercing tip  124  that generally allows for easy penetration. FIG. 12 e  shows a buck obturator tip with hook  126  that may cut and dilate in two directions, may provide an incision which is linear and easy to close and may allow for rotation of the surgeon&#39;s wrist and the obturator tip during entry. FIG. 12 f  shows a buck obturator tip  128  that generally cuts and dilates in two directions, provides a linear incision which is easy to close and allows for rotation of the surgeon&#39;s wrist and the tip during entry. FIG. 12 g  shows a swing obturator tip  130  which preferably cuts and dilates in two directions, provides a linear incision which is easy to close, and allows for rotation of the surgeon&#39;s wrist and the obturator tip during entry. FIG. 12 h  shows a 3/4 disc obturator tip  132  which generally cuts and dilates in two directions and may provide an incision which is linear and easy to close. FIG. 12 i  shows a triangular sword obturator tip  134  which may cut and dilate in two directions, may provide a linear incision which is easy to close, and generally allows for easy penetration with its double beveled  136  and pointed tip  138 . FIG. 12 j  shows a 45 degree serrated obturator tip  140  which preferably cuts and dilates in two directions, provides a linear incision which is easy to close, and its point  142  and serration  144  preferably allow ease of penetration for maximum cutting. FIG. 12 k  shows a “V” bevel obturator tip  146  which normally cuts and dilates in two directions, provides a linear incision which is easy to close and allows penetration force to be applied at two points  148  and  150 . FIG. 121 is an extended buck obturator tip  152  which generally cuts and dilates in two directions, provides a linear incision which is easy to close and allows for rotation of the surgeon&#39;s wrist and the obturator tip during entry. FIG. 12 m  shows a hooked blade obturator tip with serration  154  which may cut and dilate in two directions, may provide a linear incision which is easy to close and may allow for pointed insertion and rotation during entry. FIG. 12 n  shows a sickle obturator tip  156  which generally cuts and dilates in two directions, provides a linear incision which is easy to close and allows for pointed insertion and rotation during entry. FIG. 12 o  shows a flat obturator tip  158  that may cut and dilate in two directions, may provide a linear incision that is easy to close, and may allow for direct entry with no rotation. FIG. 12 p  shows a sickle obturator tip with reverse rotation  160  which preferably cuts and dilates in two directions, provides a linear incision which is easy to close and allows for pointed insertion and rotation during entry. 
     Although specific features of this invention are shown in some drawings and not others, this is for convenience only as each feature may be combined with any or all of the other features in accordance with the invention.