Abstract:
A catheter hub assembly comprising a hub body having a proximal end, a distal end, and a shaft having a first suture hole, a collar and a snap ring; a hub knob having a second suture hole and rotatably coupled to the hub body; and a hub cap having a snap rut wherein the snap ring fits into the snap rut. In one embodiment, the hub body includes a lock element; the hub knob includes a first tab element and a second tab element; and the hub cap includes a groove; wherein the first tab element engages the lock element; and wherein the second tab element engages the groove. In another embodiment, the hub cap includes a lock element comprising a resilient tab and a catch; the hub knob includes a catch tab; wherein the catch tab engages the catch of the lock element.

Description:
FIELD OF THE INVENTION 
     The invention generally relates to the field of catheters and more particularly to a catheter having a mechanism for retaining a distal end of the catheter in a predetermined configuration within a patient. 
     BACKGROUND OF THE INVENTION 
     Drainage catheters may be used where fluid has collected in the body and requires removal. Examples include the drainage of a hematoma (collection of blood), billoma (collection of bile), or urinoma (collection of urine). Drainage catheters may be used to percutaneously drain an abscess or pocket of fluid in the body to the exterior by means of gravity or negative pressure. Typical abscess fluids include biliary, nephrostomy, pleural, urinary, and mediastinal collection. 
     Catheterization can be used to drain the bladder after surgery or when the genitourinary system is plugged by an obstruction. Typically, drainage catheters may lie in a patient for a fairly long period of time. Accordingly, catheters have been developed with anchor structures to prevent inadvertent removal of the catheter from a patient. A “pigtail loop” as is disclosed in U.S. Pat. No. 6,231,542, is one such anchor and is formed by a flexible tube portion at the distal end of the catheter. The pigtail loop may be created in the catheter by forming the flexible tube of the catheter of a memory material. A stiff cannula or similar implement may be inserted through the catheter lumen to straighten the pigtail loop for introduction into the patient. The distal end of the flexible tube returns to the pigtail loop configuration after the cannula is removed. Alternatively, the end of the catheter can be flexible and pulled into the pigtail or other anchoring configuration by pulling a tension member, e.g. a suture wire that extends from the distal end of the catheter to and out of the catheter near its proximal end. The suture wire can be attached to draw ports located at two separated positions along the distal portion of the catheter. Pulling the suture juxtaposes the draw ports and forms a pigtail loop at the distal end of the catheter. A physician can secure the pigtail loop by grasping and pulling on one or more suture threads that lead distally from the pigtail loop. When the suture thread is taut, it prevents the pigtail loop from straightening by holding the juxtaposed portions of the catheter together. The catheter tip can be returned to its straight configuration by releasing the tension of the suture at its proximal end. 
     With some catheters, tying or locking the suture thread prevents the pigtail loop from straightening. However, if the suture thread is loosened or becomes unsecured, the pigtail loop or other anchor at the distal end of the catheter may be released and the catheter inadvertently released and withdrawn from the patient. 
     SUMMARY OF THE INVENTION 
     In accordance with one embodiment provided herein, a catheter hub assembly comprises a hub knob and a hub body disposed within the hub knob. The hub knob has an exterior surface, a through lumen and a suture hole extending from the exterior surface to the inner lumen. The hub body has a proximal end, a distal end, and a shaft having an exterior surface with an inner through lumen extending between the proximal end and the distal end. A suture hole extending from the exterior surface of the hub body to the inner lumen of the hub body. The hub knob is displaceable relative to the hub body between a first position in which the suture holes of the hub knob and hub body are aligned and a second position in which the suture holes of the hub knob and hub body are offset from one another. 
     In accordance with another embodiment, the catheter hub assembly includes a hub cap that is fixed to the distal end of the hub body. The hub cap may include a groove portion defining first and second stops, and the hub knob may include a limit member disposed in the hub cap groove for engaging the hub cap first and second stops when the hub knob is in the first and second positions respectively. 
     In accordance with another embodiment, the hub body includes a locking member that cooperates with a locking element on the hub knob to locate the hub knob in position relative to the hub body. 
     In accordance with a further embodiment, when the hub knob is in a first position relative to the hub body such that the suture holes of the hub body and hub knob are aligned, the limit member of the hub knob engages the first stop of the hub cap to limit displacement of the hub knob relative to the hub body in one direction. And when the hub knob is displaced in the opposite direction to the second position in which the suture holes of the hub knob and hub body are offset, the limit member engages the second stop of the hub cap to limit further displacement of the hub knob relative to the hub body in one direction and the locking member of the hub knob engages the stop of the locking element of the hub body to inhibit displacement of the hub knob relative to the hub body in the opposite direction. 
     In accordance with another embodiment, the catheter hub assembly includes a hub cap that is fixed to the distal end of the hub body. The hub knob may include a groove portion defining first and second stops, and the hub body may include a limit member disposed in the hub knob groove for engaging the hub knob first and second stops when the hub knob is in the first and second positions respectively. 
     In accordance with another embodiment, the hub knob includes a locking member that cooperates with a locking catch on the hub cap to locate the hub knob in position relative to the hub body. 
     In accordance with a further embodiment, when the hub knob is in a first position relative to the hub body such that the suture holes of the hub body and hub knob are aligned, the limit member of the hub body engages the first stop of the hub knob to limit displacement of the hub knob relative to the hub body in one direction. And when the hub knob is displaced in the opposite direction to the second position in which the suture holes of the hub knob and hub body are offset, the limit member engages the second stop of the hub knob to limit further displacement of the hub knob relative to the hub body in one direction and the locking member of the hub knob engages the locking catch of the hub cap to inhibit displacement of the hub knob relative to the hub body in the opposite direction. 
     Other systems, methods, features and advantages of the example embodiments will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The details of the example embodiments, including fabrication, structure and operation, may be gleaned in part by study of the accompanying figures, in which like reference numerals refer to like parts. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, all illustrations are intended to convey concepts, where relative sizes, shapes and other detailed attributes may be illustrated schematically rather than literally or precisely. 
         FIG. 1  is an exploded view of the catheter hub and catheter assembly in accordance with one embodiment; 
         FIG. 2  is an assembled view of the catheter hub shown in  FIG. 1 ; 
         FIG. 3  is a schematic view of the hub knob and hub cap shown in  FIG. 1  assembled together; 
         FIG. 4  is a detailed partial exploded view of the hub body, hub knob and hub cap assembly shown in  FIG. 1 ; 
         FIG. 5  is an assembled view of the catheter hub assembly shown in  FIG. 1  with O-ring, suture wire, and catheter in the open position. 
         FIG. 6  is an assembled view of the catheter hub assembly shown in  FIG. 1  in the closed position; 
         FIG. 7  is an exploded view of the catheter hub assembly in accordance with another embodiment; 
         FIG. 8  is a schematic of the hub body shown in  FIG. 7 ; 
         FIG. 9  is a schematic view of the hub knob and hub body shown in  FIG. 7  assembled together; 
         FIG. 10  is a partial schematic view of the hub body shown in  FIG. 7 ; 
         FIG. 11  is a schematic view of the proximal end of the hub knob shown in  FIG. 7 ; 
         FIG. 12  is a schematic view of the distal end of the hub knob shown in  FIG. 7 ; 
         FIG. 13  is a partial schematic view of the proximal end of the hub cap shown in  FIG. 7 ; 
         FIG. 14  is an assembled view of the catheter hub and catheter assembly shown in  FIG. 7  in a locked position. 
     
    
    
     It should be noted that elements of similar structures or functions are generally represented by like reference numerals for illustrative purpose throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the preferred embodiments. 
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1-2 , a catheter hub assembly  10  in accordance with one embodiment includes a hub body  100 , a hub knob  200 , and a hub cap  300 . Hub body  100  has a proximal end  110  and a distal end  180 , with a shaft  130  extending between the proximal end  110  and the distal end  180 . Shaft  130  has an exterior surface  132  and an inner through lumen  133 . The proximal end  110  of the hub body  100  may include a Luer lock  115  for connection with other apparatuses. The hub body  100  may include a collar  120  and a lock element  125  located toward the proximal end  110  on the external surface  132  of the hub body  100 . In accordance with one aspect of the invention, locking element  125  may comprise a ramp portion  128  that increases in height along the exterior surface of the hub body  100  to a stop portion  126 . 
     The shaft  130  of the hub body  100  may include a recessed area  140  for receiving an O-ring  145 . A suture hole  150  is disposed in the recessed area  140  and passes through to the inner lumen to allow one or more suture wires  500  or tension members to pass through. The O-ring  145  seals the suture hole  150  to ensure that the catheter hub  10  does not leak. 
     The hub body  100  may further include a flair element  185 , a snap ring  190 , and an alignment key  195  located adjacent the distal end  180  of the hub body  100 . The flair element  185  of the hub body  100  is adapted to mate with a catheter  400 . 
     Still referring to  FIGS. 1-2 , the hub knob  200  has a proximal end  210 , a distal end  280 , an exterior surface  232  and an inner through lumen  233  into which is received the shaft  130  of hub body  100  such that hub knob  200  is displaceable, e.g. rotatable relative to hub body  100 . Preferably, collar  120  fits over the peripheral edge of proximal end  210  of hub knob  200 . Hub knob  200  may also include a locking member  225  and a suture hole  250  extending from the exterior surface  232  to the inner lumen  233 . Preferably locking member  225  is a resilient member that extends from the proximal end of hub knob  200  and is spring biased toward the exterior surface of hub shaft  130 . It is also preferable that locking member  225  includes an outwardly flared tip portion  226  that facilitates displacing the locking member  225  in a direction away from hub body  100 . Hub knob  200  may also include a limit member  275  disposed at its distal end  280 . 
     Referring to  FIGS. 1-4 , the hub cap  300  has a proximal end  310 , a distal end  380  and a through lumen  333 . A groove  375  defining a first stop portion  376  and a second stop portion  377  may be disposed at the proximal end  310 . Limit member  275  of the hub knob  200  is received in groove  375 . Hub cap  300  may also include a snap groove  390  and an alignment port  395 . Snap ring  190  of the hub body  100  fits into a snap rut or groove  390  of the hub cap  300  to secure the hub body  100  to the hub cap  300 . The distal end  380  of the hub cap  300  is adapted to capture the catheter  400  to be secured to the flair element  185  of the hub body  100  when the catheter hub  10  is assembled. The exterior of the hub cap  300  can be used to identify the catheter French size with which it can be used. Preferably, in accordance with one aspect of the invention, alignment key  195  of hub body  100  is received within alignment port  395  of hub cap  300  to properly align hub body  100  with the hub cap  300 . 
     Referring to  FIG. 5 , the catheter hub  10  is shown assembled and attached to a catheter  400  with the hub knob  200  being disposed in a first open position in which the suture holes  250  and  150  are aligned with one another. Preferably, locking member  225  is disposed in a first position overlying ramp portion  128  and out of engagement with stop portion  126 . It is also preferable that in this first open position, limit member  275  engages stop  376  (see  FIG. 3 ) to prevent further rotation of hub knob in a counterclockwise direction. In this open position, suture wire  500  is freely moveable through the suture holes  250  and  150  and can be readily pulled out of hub knob  200  which effects the pulling of the flexible end  426  of catheter  400  into the pigtail configuration shown in  FIG. 6 . Further referring to  FIG. 6  and  FIG. 2 , hub knob  200  may be rotated in a clockwise direction until locking member  225  traverses ramp position  128  of locking element  125  and because of its spring bias snaps into engagement with stop portion  126  of locking element  125 . Stop  126  limits counter-rotation of hub knob  200  in the clockwise direction. 
     Referring to  FIG. 6 , this second position of hub knob  200  is a locked position because suture holes  250  and  150  are now offset relative to one another and suture wire  500  is trapped between the inside surface of hub knob  200  and the outside surface of hub body  100 . This trapping or locking of suture wire  500 , effectively keeps suture wire stationary so as to maintain the catheter end  426  in position, e.g., in the pigtail configuration of  FIG. 6 . Preferably, in this closed position, limit member  375  also engages stop  377  to prevent further rotation of hub knob  200  in a clockwise direction. To unlock the assembly, a user can pull back resilient locking member  225  to raise it over stop  126  so as to disengage it from stop  126 . Hub knob  200  can then be rotated in a clockwise direction such that locking member  225  engages the ramp portion of 128 locking element  125  to the open position where suture holes  250  and  150  are again aligned and suture wire can be readily moved and the catheter pigtail configuration straightened out so that the catheter can be removed from the patient. 
     Referring to  FIGS. 7-8 , a catheter hub assembly  1010  in accordance with another embodiment includes a hub body  1100 , a hub knob  1200 , and a hub cap  1300 . Hub body  1100  has a proximal end  1110  and a distal end  1180 , with a shaft  1130  extending between the proximal end  1110  and the distal end  1180 . Shaft  1130  has an exterior surface  1132  and an inner through lumen  1133 . The proximal end  1110  of the hub body  1100  may include a Luer lock  1115  for connection with other apparatuses. The hub body  1100  may include a collar  1120 . 
     The shaft  1130  of the hub body  1100  may include a recessed area  1140  for receiving an O-ring. A suture hole  1150  is disposed in the recessed area  1140  extending to the inner lumen  1133  to allow one or more suture wires to pass through. The O-ring seals the suture hole  1150  to ensure that the catheter hub  1010  does not leak. 
     The hub body  1100  may further include a flair element  1185  and a snap ring  1190  located adjacent the distal end  1180  of the hub body  1100 , and an alignment keyway  1195  extending from adjacent the distal end  1180  of the hub body  1100  longitudinally along the outer surface  1132  of the hub body  1100  toward the proximal end  1110 . The flair element  1185  of the hub body  1100  is adapted to mate with a catheter. Opposing recesses  1176  and  1177  are formed along the exterior surface  1132  of the hub body  1100  increasing in depth as they extend toward the proximal end  1110  of the hub body  1100 . 
     Referring to  FIGS. 7-11 , the hub knob  1200  has a proximal end  1210 , a distal end  1280 , an exterior surface  1232  and an inner through lumen  1233  into which is received the shaft  1130  of hub body  1100  such that hub knob  1200  is displaceable, e.g. rotatable relative to hub body  1100 . Preferably, collar  1120  fits within the proximal end  1210  of the hub knob abutting arcuate stop  1278  such that the proximal face of the collar  1120  is flush with the peripheral edge of proximal end  1210  of hub knob  1200 . Hub knob  1200  may also include a suture hole  1250  extending from the exterior surface  1232  to inner lumen  1233 . A groove  1275  defining a first stop portion  1276  and a second stop portion  1277  may be disposed internally adjacent the proximal end  1210  of the hub knob  1200 . Limit member  1125  extending from the collar  1120  of the hub body  1100  is received in groove  1275  and engages stop portions  1276  or  1277  to limit rotation of the hub knob  1200 . 
     Referring to  FIGS. 7-13 , hub cap  1300  has a proximal end  1310 , a distal end  1380  and an inner through lumen  1333 . Hub cap  1300  may also include a snap groove along the inner through lumen  1333  adjacent the distal end  1310  and an alignment key  1395  extending along the inner through lumen  1333 . Preferably, the alignment key  1395  of hub cap  1300  is received within alignment keyway  1195  of hub body  1100  to properly align the hub body  1100  with hub cap  1300 . Snap ring  1190  of the hub body  1100  fits into the snap groove (see, e.g.,  390  in  FIG. 4 ) of the hub cap  1300  to secure the hub body  1100  to the hub cap  1300 . The distal end  1380  of the hub cap  1300  is adapted to capture a catheter to be secured to the flair element  1185  of the hub body  1100  when the catheter hub  1010  is assembled. The exterior surface  1332  of the hub cap  1300  may have a depression  1302  that can be used to identify the catheter French size of the device. 
     Preferably the proximal end  1310  of the hub cap  1300  is divided into two opposing resilient members  1360  and two opposing non-resilient members  1370  with adjacent resilient and non-resilient members  1360  and  1370  being in spaced relation with gaps  1372  extending longitudinally between members  1360  and  1370 . The resilient members  1360  are outwardly spring biased. Catch or locking members  1362  preferably extend proximally from resilient members  1360 . The catch members  1362  have a first ramped or arcuate forward surface  1363 , a second ramped or arcuate rear surface  1365  and a recessed catch  1364  formed there between. Catch tabs  1260  formed on the interior of the hub knob  1200  cooperate with the catch members  1362  to positively position the hub knob  1200  in the locked and unlocked positions. As the hub knob  1200  is rotated toward the locked position, the catch tabs  1260  engage the ramped surface  1363  of the catch members  1362  deflecting the resilient members  1360  inward toward the hub shaft  1130 . When the catch tabs  1260  reach the recessed catches  1364 , the resilient members  1360  because of their spring bias spring outward toward the hub knob  1200  giving a snap like feel to the positioning of the hub knob  1200  in the locked position. Further rotation of the hub knob  1200  is prevented by one of the stop portions  1276  or  1277  defined by the groove  1275  in the hub knob  1200  and the limit member  1125  of the hub body  1100 . 
     To release the hub knob  1200  and rotate it from a locked position to an unlocked position, buttons  1366  formed on the exterior of the resilient members  1360  are pressed to deflect the resilient members  1360  inward and release the catch tabs  1260  from the recessed catches  1364 . As the hub knob  1200  is rotated toward the unlocked position, the catch tabs  1260  engage the second ramped surface  1365  of the catch members  1362  deflecting the resilient members  1360  inward toward the hub shaft  1130 . When the catch tabs  1260  reach the recessed catches  1364 , the resilient members  1360  move outward toward the hub knob  1200  to positively position the hub knob  1200  in the unlocked position. Further rotation of the hub knob  1200  is prevented by one of the stop portions  1276  or  1277  defined by the groove  1275  in the hub knob  1200  and the limit member  1125  of the hub body  1100 . 
     Preferably, the recessed catch  1364  has a first surface  1367  that acts as a stop to prevent rotation of the hub knob  1200  from the locked to the unlocked position without deflecting the resilient members  1360  inward, and a ramped surface  1368  that the catch tabs  1260  engage to deflect the resilient members  1360  inward to allow the hub knob  1200  to rotate from the unlocked position to the locked position. 
     Referring to  FIG. 14 , the catheter hub assembly  1010  is shown with the hub knob  1200  being disposed in a locked position in which the suture holes  1250  and  1150  offset from one another. As a result, the suture wire  500  is locked in place between the hub knob  1200  and the hub body  1100  extending between suture holes  1250  and  1150  which effects holding the flexible end of catheter  1400  into a pigtail configuration. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the apparatus and method of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.