Abstract:
A tube-based catheter and needle system providing spring retraction of a needle subsequent to patient access. A retraction spring is connected to the needle and maintained in an energized state prior to activation. Rotation of a tube portion relative to the needle causes a spring release and retraction of the needle into a safety tube.

Description:
RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Application Ser. No. 60/715,564, filed Sep. 8, 2005. 
     
    
     TECHNICAL FIELD  
       [0002]     The invention relates to an intravenous access system and more particularly to a catheter and safety tube needle retraction system.  
       BACKGROUND OF THE INVENTION  
       [0003]     Catheters are commonly used to provide intravenous access, for example to obtain a blood sample from a patient. Catheters are typically utilized with a needle, wherein the needle is used to puncture the skin and position the catheter within a vein. The needle is then retracted and the catheter remains in place. Needle safety tubes have been used in conjunction with catheters to protect the user from accidental needle sticks during needle retraction and disposal. Prior to coupling a catheter to another device or line, the user often first tamponade the vein with gauze or other material to prevent excessive bleeding and then rapidly retract the needle and guide it into a safety tube without incurring a needlestick or blood born exposure. It is during this needed retraction and tamponading that a number of needlesticks and blood born exposures occur.  
         [0004]     Some safety catheters use a trigger that actuates a spring to retract the needle into a safety tube. Such retraction systems have significant limitations, including inadvertent exposure to blood as the user may be exposed to blood spray or blood “back-splash” during a spring retraction process. Unsuccessful tamponading of the vein may also lead to blood exposures during IV line attachment. Another limitation is that the trigger is often not adequately protected from inadvertent actuation. Inadvertent actuation results in needle retraction before the catheter is successfully inserted, causing significant blood-born exposures and unsuccessful IV attempts.  
         [0005]     Consequently, there is a need for a safety catheter needle retraction system that protects users from both needlesticks and blood-born exposures, and also improves the simplicity and dependability of the needle retraction process for users.  
       BRIEF SUMMARY OF THE INVENTION  
       [0006]     The present invention is directed to a safety catheter needle retraction system having a selectively retractable needle. An embodiment of the present invention includes a trigger assembly requiring the user to deliberately rotate a portion of the device in order to actuate the mechanism and retract the needle. The use of a safety stop prevents a user from separating the catheter from the safety tube without first retracting the needle. Blood back-splash exposures and spring strength are minimized as the needle retracts through a self-sealing injection port, which “wicks” or “squeegees” the blood off the needle as it passes through the membrane.  
         [0007]     A retraction mechanism of an embodiment of the safety catheter needle retraction is spring actuated. The retraction spring provides needle extraction and containment within the safety tube. The safety tube assembly allows the user to easily grasp and manipulate the catheter during an IV start, and permits easy storage in drug boxes and crash carts.  
         [0008]     The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which:  
         [0010]      FIG. 1  is a side elevation view of the safety catheter system according to the present invention;  
         [0011]      FIG. 2  is a perspective illustration of a piercing needle and needle carrier of the catheter system of  FIG. 1 ;  
         [0012]      FIG. 3  is a perspective illustration of components of a retraction spring assembly;  
         [0013]      FIG. 4  is a cross-section view of a safety tube assembly and trigger pins of the catheter system in  FIG. 1 ;  
         [0014]      FIG. 5  is a cross section view of the safety tube assembly, piercing needle and retraction spring of the catheter system in  FIG. 1 ;  
         [0015]      FIG. 6  is a front elevational view of the safety tube assembly of  FIG. 5 ;z  
         [0016]      FIG. 7  is a perspective illustration of the safety tube assembly of  FIG. 5 ;  
         [0017]      FIG. 8   a - FIG. 8   e  depict operation of the catheter and safety tube assembly;  
         [0018]      FIG. 9   a - FIG. 9   d  depict operation of the safety tube trigger and needle retraction into safety tube;  
         [0019]      FIG. 10  is a cross-section view of the safety tube assembly and trigger of the catheter system of  FIG. 1 ;  
         [0020]      FIG. 11  is a perspective illustration of portions of the safety tube assembly and needle-tip cover of  FIG. 4 ; and  
         [0021]      FIG. 12  is a perspective illustration of portions of the safety tube assembly, needle and needle retraction system according to one embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]     An embodiment of a catheter system according to the present invention is shown in  FIGS. 1-12  and is referenced herein by the numeral  10 . Referring to  FIG. 1 , catheter system  10  includes an over-the-needle type “closed hub” catheter assembly  12  with a connecting U-port coupling  46  disposed at the front or proximal end of the catheter system  10 . Safety tube assembly  16  is disposed at the rear or distal end of catheter system  10 . Catheter assembly  12  includes a relatively long venous-gauge coring-tipped needle  18  having an angled distal point  20  for percutaneous penetration of a patient&#39;s skin and vascular system. As described in more detail hereinafter, safety tube assembly  16  includes a slide-biased needle-tip cover  15  providing needle protection. Additional aspects of catheter assembly  12  and U-port coupling  46  are disclosed in U.S. Ser. No. 10/797,526, entitled “Vascular Access Device and Method of Using Same,” the entire disclosure being incorporated by reference herein.  
         [0023]     Referring to  FIGS. 1-3 , needle  18  defines side aperture  48  positioned near the proximal end of catheter cannula  30  such that the side aperture  48  vents blood into blood flash chamber  28  in a manner so as to be visible through a transparent distal region of flash chamber  28 . Side aperture  48  is shown for illustrative purposes as an elongated opening or groove in needle  18 , but it may be appreciated that a small bore hole oriented, for example, perpendicular to or at an angle relative to the longitudinal axis of needle  18  may be sufficient in other applications. A portion  47  of needle  18  is tapered in order to reduce needle diameter. An end of needle  18  is fixedly attached to and partially embedded into needle carrier  50  which is sized and geometrically configured so as to be engaged and slidably received within safety tube assembly  16  as described in further detail below, and to maintain a proper orientation of the needle  18  and distal point  20  within housing  28  and catheter tube  30 . Needle carrier  50  further defines arms  49  extending outwardly in opposing directions from the center of needle carrier  50 . Arms  49  operate in conjunction with needle carrier arm stops  52 , shown in  FIG. 3 , extending radially inward from retraction spring base  51 . Needle carrier arm stops  52  act to stabilize and prevent any rotation of piercing needle  18  attached to needle carrier  50 , prior to needle retraction. Retraction spring base  51  is sized and geometrically configured so as to be engaged and slidably received within safety tube assembly  16 . Retraction spring base  51  receives a portion of piercing needle  18  through aperture  64  and needle carrier  50  and needle carrier arms  49  seats between needle carrier arm stops  52 . Retraction spring  62  is attached and embedded in one of the needle carrier arm stops  52 .  
         [0024]     Referring particularly to  FIG. 4 , additional components of safety tube  16  are shown in greater detail. In one embodiment, two trigger pin projections  70  are situated within safety tube  16  such that needle carrier arms  49  rest against the trigger pins  70  and are used in restraining and then releasing needle carrier  50  into safety tube  16 . A lubricant or low friction surface(s) may be provided at the interface between arms  49  and pins  70  to facilitate a sliding connection therebetween. One end of safety tube  16  includes a catheter gripping area  72  adapted to provide a user with a non-slippery surface permitting a user to safely grasp catheter device  10  in order to insert the cannula  30  into a patient. Catheter-gripping surface  72  may have a roughened, textured and/or raised surface to aid the user in gripping device  10  during use. Catheter grip area  72  is preferably provided within a region of tube  16  which, when rotated during trigger actuation, will also act as a blood splash shield during a needle retraction procedure. Two needle-tip slide cover channels  71  are provided generally opposite to catheter grip area  72 . Channels  71  carry needle-tip slide cover  15  which, in this embodiment, has hemispherical protrusions that slide within slide cover channels  71 . Needle-tip slide cover  15  is pulled along needle-tip slide cover channels  71  by needle cover tab safety stop  76  which is engaged with a tab (not shown) on catheter assembly  12  when advanced into the vasculature of the patient. When the catheter is fully advanced, needle-tip slide cover  15  locks into needle-tip cover locking detent  77  located at the distal end of safety tube  16 . In this manner, needle-tip slide cover  15  acts to protect piercing tip  20  of needle  18 .  
         [0025]     Referring particularly to  FIGS. 5-7 , in one embodiment, safety tube  16  can be seen in a “cocked” or pre-use state. To aid in clarity, closed hub catheter  46  is not shown mounted over the piercing needle  18  and nestled near the gripping surface area  72 .  FIG. 6  shows how needle carrier arms  49  rest against trigger pins  70  to restrain needle  18  until the safety tube  16  is rotated to free trigger pins  70  from the back of needle carrier arms  49 .  
         [0026]     Referring particularly to  FIGS. 8   a - 8   e , one embodiment of catheter system  10  is shown composed of an over-the-needle type “closed hub” safety catheter assembly  12  with U-port coupling  46  disposed at the front or distal end of catheter system  10  and safety tube assembly  16  disposed at the rear or proximal end of the catheter system  10 .  FIGS. 8   a  thru  8   e  show the progression of steps required to insert catheter assembly  12  and then activate needle retraction system.  FIG. 8   a  shows catheter system  10  as it is removed from a sterile packaging and with a needle guard removed (ready for first use).  FIG. 8   b  depicts the catheter  12  advancing into vasculature while needle cover tab safety stop  76  is pulling needle-tip slide cover  15  along to the distal end of safety tube  16 .  FIG. 8   c  shows safety tube system  16  rotated 45 degrees. This rotation converts catheter gripping area  72  into a blood splash shield as the needle is retracted out of catheter  12 .  FIG. 8   d  shows the safety tube fully rotated 180 degrees. Ideally, at approximately 170 degrees, the safety tube rotation triggers the needle retraction system to retract needle  18  into safety tube  16 .  FIG. 8   e  shows catheter system  12  separated from safety tube  16  and piercing needle  18  safely stored within safety tube  16  with the needle-tip  20  protected by needle-tip cover  15 .  
         [0027]      FIGS. 9   a - 9   d  illustrate aspects of operation of an embodiment of the present invention. In  FIG. 9   a , the triggering system is “cocked” and in its initial orientation. Needle  18  is restrained from retraction parts  51  and  62  by needle carrier arms  49  contacting trigger pins  70 .  FIG. 9   b  shows the initial rotation of needle safety tube  16 . This rotation also rotates attached trigger pins  70 , when trigger pins  70  rotate to clear contact with needle carrier arms  49 , piercing needle  18  retracts. Needle carrier arm stops  52  act to restrain shadow rotation of needle carrier arms  49  with trigger pins  70 , during rotation, needle carrier arms  49  rotate with trigger pins  70  until needle carrier arms  49  contact needle carrier arm stops  52 , allowing arms  49  to stop rotation and clear the trigger pins  70 .  FIG. 9   c  illustrates needle carrier arms  49  now clear of trigger pins  70  and retraction spring base  51  and attached pre-stretched/flexed spring  62  starting to retract (arrow) piercing needle  18 .  FIG. 9   d  shows piercing needle  18  fully retracted into safety tube  16 . Spring  62  is then fully compressed carrying retraction spring base  51 , needle carrier  50  and piercing needle  18  to the proximal end of safety tube  16 . The spring tension of retraction spring  62  will hold piercing needle  18  within the confines of safety tube  16 .  
         [0028]      FIG. 10  illustrates a partial cross-sectional view of components of the safety tube trigger mechanism of  FIGS. 9   a - 9   d . Pre-tensioned retraction spring  62  is attached to retraction spring base  51  by mounting into one of needle carrier arm stops  52 . Needle-tip cover  15  is shown in its retracted position and engaging needle cover drag tab  76 . As catheter  12  is advanced, a tab on the back of catheter  12  (not shown) engages needle cover drag tab  76  and pulls needle-tip cover  15  along needle-tip cover slide channels  71  and into its locked position at the distal end of safety tube  16 .  FIG. 10  shows that trigger pins  70  restrain needle  18  by contact with needle carrier  50 .  
         [0029]      FIG. 11  discloses one embodiment of the needle-tip cover  15  and its relationship with safety tube  16 . Two parallel needle-tip cover slide channels  71  are provided within an upper portion of gripping area  72 . Slide channels  71  allows needle-tip cover  15  to travel from its initial position, shown in  FIG. 10 , at the proximal end of gripping area  72  to its locked position at the distal end of gripping area  72 . Needle-tip cover  15  locks into the needle-tip cover lock/stop  77  to prevent the needle-tip cover from retracting and exposing the piercing needle-tip  20 . Needle cover advancement projection  76  is shown near one end of needle-tip cover  15 .  
         [0030]      FIG. 12  discloses one embodiment of the retracted state of the components of safety tube assembly  16 . This view shows needle-tip cover  15  in its locked state utilizing the needle-tip cover locks  77 , and protecting piercing tip  20  of needle  18 . Retraction spring  62  holds piercing needle  18  within the confines of safety tube  16 . Safety tube  16  can then be safely disposed.  
         [0031]     Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.