Abstract:
A safety introducer for insertion into a vessel of a patient for infusion of fluids into or withdraw of fluids from the vessel. The introducer includes a catheter assembly having a catheter tube attached to a catheter body. The catheter body has an elongated cavity extending therethrough which is in fluid communication with the catheter tube. The introducer further includes a needle assembly having an elongated needle attached to a flexible tube. The flexible tube is in fluid communication with the elongated cavity. The needle assembly is slidably disposed within the elongated cavity such that a proximally directed force exerted on the flexible tube withdraws the needle assembly substantially completely within the elongated cavity.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention generally relates to intravenous (IV) catheters; and more particularly, the invention relates to a safety catheter with a retractable needle fixed to the catheter.  
         BACKGROUND OF THE INVENTION  
         [0002]    An intravenous (IV) catheter is an instrument that is used to introduce certain fluids such as saline solution directly into the bloodstream of a patient. Typically, a needle or other stylet is first introduced through the cannula portion of the catheter and into the skin of the patient at the desired location such as the back of the patient&#39;s hand or a vessel on the inside of the arm. Once insertion is complete, the needle is removed from the cannula portion of the catheter. After removing the needle, a fluid handling device such as a syringe or IV bag is attached to the luer fitting located at the proximal end of the catheter hub. Fluid is then infused directly from the fluid handling device through the catheter into the bloodstream of the patient.  
           [0003]    When the needle is removed from the cannula, the health care worker must place the exposed needle tip at a nearby disposal unit while simultaneously addressing the task required to infuse the fluids into the patient. It is at this juncture that the exposed needle tip creates a danger of an accidental needle stick occurring which leaves the health care worker vulnerable to the transmission of various, dangerous blood-borne pathogens such as human immune virus (HIV) and hepatitis. The risk of a contaminated needle stick is not just isolated to the health care worker inserting the intravenous catheter. Careless disposal of used needles can put other health care workers at risk as well. Even others outside the health care profession, for example those involved in the clean-up and final disposal of medical waste can be at risk of an accidental needle stick from a carelessly discarded needle.  
           [0004]    The danger to health care workers and others outside the health care profession from accidental needle sticks has yielded the development of catheters with safety mechanisms in which the occurrence of such accidental needle sticks is prevented. An example of a catheter having a safety mechanism is disclosed in U.S. Pat. No. 6,077,244 issued to Botich et al. on Jun. 20, 2000. A catheter insertion device is described in which the needle is retracted within the housing of the device after use to prevent contaminated needle exposure. A needle retainer releasably retains the needle in an extended position against the rearward bias of the biasing element. The needle retainer engages the hub of the catheter so that when the catheter is removed from the insertion device, the needle retainer automatically releases the needle. The biasing element then propels the needle rearwardly into the housing of the device. The housing can then be safely removed from the catheter enabling a fluid handling device to be attached to the catheter hub.  
           [0005]    The advancement of such safety mechanisms on catheters have reduced concerns associated with inadvertent needle sticks; however, there is still opportunity for improvement. The catheters in the prior art have safety mechanisms which shield the needle tip during removal from the catheter to prevent inadvertent needle sticks. Even though the needle tip is shielded, there is still a risk of an accidental needle stick to health care workers or others outside the health care profession. For example, a needle might not retract entirely into its shield or housing. After the needle is removed from the catheter, the tip would be exposed creating a risk of an accidental needle stick. In addition, the safety mechanisms on the catheters in the prior art were not developed to eliminate the risk of exposure to bodily fluids. For example, when the health care worker removes the needle from the catheter, the tip even though safety shielded might discharge some bodily fluids on his gloves. The health care worker could then proceed to inadvertently touch his eye while still wearing the gloves creating a risk of infection from the discharged bodily fluid. In addition, safety catheters of the type mentioned above require the health care worker to separately dispose of the needle and the catheter, thereby providing for two instances where the health care worker is at risk.  
           [0006]    Therefore, there has been a desire for an improved catheter which reduces the risk of an inadvertent needle stick and bodily fluid exposure.  
         SUMMARY OF THE INVENTION  
         [0007]    In accordance with the present invention there is provided a safety introducer for insertion into a vessel of a patient for infusion of fluids into or withdraw of fluids from the vessel. The introducer includes a catheter assembly with an elongated catheter tube having lumen extending from a distal end to a proximal end. The proximal end of the tube is attached to a distal end of a catheter body. The catheter body has an elongated cavity extending therethrough from the distal end to a proximal end. The cavity is in fluid communication with the catheter tube. The introducer further includes a needle assembly with an elongated needle having a lumen extending from a distal end to a proximal end. The proximal end of the needle is attached to a distal end of a flexible tube. The flexible tube has a lumen extending from the distal end to a proximal end which is in fluid communication with the elongated cavity. The needle assembly being slidably disposed within the elongated cavity such that a proximally directed force exerted on the flexible tube withdraws the needle assembly substantially completely within the elongated cavity. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    The novel features of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to organization and methods of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings in which:  
         [0009]    [0009]FIG. 1 is a perspective view of a intravenous assembly including the catheter assembly and needle assembly of the present invention.  
         [0010]    [0010]FIG. 2 is a cross-sectional view along  2 - 2  of FIG. 1 of the intravenous assembly showing the needle exposed distally from the catheter.  
         [0011]    [0011]FIG. 3 is a cross-sectional view similar to FIG. 2 of the intravenous assembly showing the needle retracted within the catheter body.  
         [0012]    [0012]FIG. 4 is perspective view of the needle assembly of the present invention.  
         [0013]    [0013]FIG. 5 is perspective view of the coupler of the needle assembly of the present invention.  
         [0014]    [0014]FIG. 6 is a cross-sectional view taken along line  4 - 4  of the coupler of the present invention.  
         [0015]    [0015]FIG. 7 is a cross-sectional view of an alternate embodiment of the present invention.  
         [0016]    [0016]FIG. 8 is a cross-sectional view of another alternate embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]    As used in this description, “proximal” or “proximally” refers to that portion of the instrument, component, or element which extends toward the user. Conversely, “distal” or “distally” refers to that portion of the instrument, component, or element which extends away from the user.  
         [0018]    Referring to FIGS. 1, 2, and  3 , IV assembly, or safety introducer,  2  of the present invention includes catheter assembly  4  and needle assembly  20 . Needle assembly  20  includes needle  22  and coupler  24 . As illustrated in FIG. 4, needle  22 , which is preferably made of stainless steel, is generally an elongated tubular structure with proximal end  51  and distal end  52 . Proximal end  51  of needle  22  is fixedly attached to glue well  28  on the distal end of coupler  24 . Coupler  24  which is preferably made of a translucent or transparent polymer such as, for example, polycarbonate, is generally a tubular structure having coupler cavity  38  in fluid communication with lumen  21  of needle  22 . Coupler  24  further comprises side ports  32  and  34  and bullet end  30  (shown in FIG. 5). As illustrated in FIGS. 5 and 6, side ports  32  and  34  are openings normal to the axis of coupler  24  which allow fluid to pass therethrough. Side ports  32  and  34  are in fluid communication with coupler cavity  38   
         [0019]    Referring back now to FIGS. 1 and 2, needle assembly  20  further comprises tube  26  and a sealing member, or tube bulge,  40 . Tube  26  is preferably made of a flexible PVC, but can be made from any number of materials known to those skilled in the art. Tube  26  is generally a tubular structure having proximal end  53  and distal end  54 . Proximal end  53  of tube  26  is fixedly attached to luer fitting  36 . Luer fitting  36 , well known in the medical art, provides for secure, leak proof attachment of tubing, syringes, or many other medical devices used to infuse or withdraw fluids through IV assembly  2 . Distal end  54  of tube  26  is inserted over bullet end  30  (see FIG. 5) of coupler  24  creating tube bulge  40 . Tube bulge  40  is generally a semi spherical structure, which is described in more detail later.  
         [0020]    Referring again to FIGS. 2 and 3, catheter assembly  4  includes an elongated catheter tube  6  which is a tubular structure having proximal end  55  and a distal end  56 , and a lumen  50  extending therebetween. Catheter  6  could be comprised of many suitable materials known in the art most of which are flexible thermoplastics such as, for example, polyurethane. Catheter cap  8  is generally a conical structure having proximal end  57  and distal end  58 . Distal end  58  of catheter cap  8 , which has an opening therethrough, is fixedly attached to proximal end  55  of catheter  6 . Catheter cap  8  may be made from a suitable, rigid polymer such as, for example, polypropylene. Catheter assembly  4  further includes catheter body  10 , which is preferably made of a translucent or transparent polymer such as, for example, polycarbonate. Catheter body  10  is generally a tubular structure with body cavity  12  therethrough having proximal end  59  and distal end  60 . Distal end  60  of catheter body  10  is fixedly attached to proximal end  57  of catheter cap  8 .  
         [0021]    Prior to attaching catheter body  10  and catheter cap  8 , needle  22  is inserted through catheter cap  8  and catheter  6  extending distally therefrom. Distal end  60  of catheter body  10  is then slipped over proximal end  53  of tube  26 . Catheter body  10  is then advanced toward the distal end of needle assembly  20 . Sliding catheter body  10  over tube bulge  40  creates a seal fit which prevents fluids from escaping through proximal end  59  of catheter body  10  and creates a frictional fit with body cavity walls  14  and  16  which limits the travel of needle assembly  20 . After advancement is complete, distal end  60  of catheter body  10  is attached to proximal end  57  of catheter cap  8 , which has needle  22  therethrough. Luer fitting  36  is then attached to proximal end  53  of tube  26 .  
         [0022]    In an actual intravenous insertion procedure utilizing the device of the present invention, a health care worker positions IV assembly  2  at the desired location. The health care worker then proceeds to apply pressure on IV assembly  2  causing needle  22 , which extends distally from catheter  6  to pierce the skin of the patient. Continuing to apply pressure, the health care worker advances IV assembly  2  distally into the vein of the patient. During advancement, needle  22  creates a hole allowing catheter  6  to be inserted into the vein. After insertion is complete, the health care worker pulls on proximal end  53  of tube  26  which retracts needle  22  from catheter  6  into catheter body  10  and catheter cap  8  of IV assembly  2 , as shown in FIG. 3. While needle  22  is retracted into catheter body  10  and catheter cap  8 , blood may flow up into body cavity  12  of catheter body  10 , but the fit between body cavity wall  14  and tube bulge  40  creates a seal which does not allow the blood to escape out of the proximal end of IV assembly  2 . Tube  26  is pulled until tube bulge  40  stops against proximal cavity wall  16  of catheter body  10 . A fluid handling device such as, for example, a syringe can then be attached to luer fitting  36  to proximal end  53  of tube  26 . Fluid then flows directly from the fluid handling device through tube  26 , coupler  24 , needle  22 , and catheter  6  into the bloodstream of the patient. Some of the fluid will pass out side ports  32  and  34  of coupler  24  washing any residual blood back into the vein not allowing it to sit and become stagnate.  
         [0023]    As seen from the above description, the present invention has many advantages over prior art safety catheters. A guidewire is not needed to retract the needle. Instead, the flexible tube retracts the needle. This design allows for a reduced number of parts, as the guidewire can be eliminated. Because the needle assembly is not separated from the catheter assembly at the time of insertion, there is only one single unit to dispose of when the product is finished.  
         [0024]    An alternate embodiment of the present invention is shown in FIG. 7. In this embodiment, coupler  124 , similar to coupler  24 , includes seal  150  attached to the distal end of coupler  124 . Seal  150  replaces tube bulge  40  in the preferred embodiment. Seal  150  is generally a doughnut shape made of a material such as, for example, silicone or any other flexible material known to those skilled in the art. Attached to the distal end of coupler  124 , seal  150  completely surrounds tube  126  preventing fluids from escaping catheter body  110 .  
         [0025]    [0025]FIG. 8 shows another alternate embodiment where coupler  224 , similar to coupler  124 , includes seal  250 . Seal  250  which functions to replace tube bulge  40  in the preferred embodiment is fixedly attached to distal cavity walls  217  and  218  of catheter body  210 . Seal  250  is generally a doughnut shape made of a material such as, for example, silicone or any other flexible material known to those skilled in the art. Completely surrounding distal end  252  of needle  222 , seal  250  prevents fluids from escaping catheter body  210 .  
         [0026]    While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. In addition, for each structure mentioned above, it should be understood that such structure can be described or characterized as a means for performing its intended function. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.