Abstract:
A catheter assembly for insertion into a vessel of a patient. The catheter assembly includes an elongate hollow tubular catheter having a distal end and a proximal end. The proximal end of the catheter has a hub attached thereto. The catheter assembly further includes a needle assembly having an elongated needle with a sharpened distal end and a proximal end. The needle is disposed within the catheter prior to insertion into a patient with the distal end of the needle being distal to the distal end of the catheter. The catheter assembly also includes a safety assembly. The safety assembly has a first position for protecting the sharpened distal end of the needle, and a second position for exposing the sharpened distal end of the needle. The safety assembly normally being in the first position and being movable to the second position for insertion into the vessel of a patient.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates, in general, to intravenous (IV) catheters and, more particularly, to a safety IV catheter with a needle tip protector that will protect the clinician from the needle tip before, during, and after use.  
         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 is attached to the luer fitting located at the proximal end of the catheter hub. Fluid then flows directly from the fluid handling device through the catheter into the bloodstream of the patient.  
           [0003]    Before the needle is introduced through the catheter and into the skin of the patient, a health care worker prepares the IV for use. The needle tip is exposed in this reparation creating a danger of an accidental needle stick to the health care worker which may cause injury. After preparation, the health care worker proceeds to insert the catheter into the vein of the patient. During insertion, the patient may suddenly move after the catheter is inserted into the vein, but before the needle tip protector is activated leaving the needle tip exposed. In addition, when the needle is removed from the cannula after insertion is complete, the health care worker must place the exposed needle tip at a nearby location while simultaneously addressing the task required to accomplish the needle removal. An exposed needle tip during insertion and removal 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.  
           [0004]    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, are at risk of an accidental needle stick from a carelessly discarded needle.  
           [0005]    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. Re. 34,416 issued to Lemieux. A safety catheter is described which includes an element that covers the needle tip upon removal of the needle from the catheter. The safety element includes a split flange at its proximal end which is expanded by the needle as the needle is inserted into an undersized hole at the center of this flange. The safety element is thus held secure within the catheter hub by inserting the needle through the undersized hole which forces the outside perimeter of the split flange against the inside wall of the catheter hub. One of the drawbacks to this design is the amount of friction force exerted against the needle by the split flange. A tight fit of the flange against the catheter wall causes great friction against the needle making it difficult to be withdrawn from the catheter by the clinician. A lose fit leaves the flange prone to releasing prematurely from the catheter as the needle is withdrawn, creating the potential that the needle tip will be left exposed. Another drawback to this design is that the needle is not protected before and during the insertion of the catheter into the patient creating the risk of an accidental needle stick.  
           [0006]    Another example of a catheter having a safety mechanism is disclosed in U.S. Pat. No. 4,828,547 issued to Sahi et al. A self-blunting needle assembly is described comprising a hollow needle, which may be of conventional construction having a needle mouth and a needle shank terminating in a puncture tip. The hollow needle further includes a blunting member mounted therein including an elongate probe which slidably fits within the bore of the needle shank. The probe terminates in a distal tip which is initially positioned short of the puncture tip of the needle so as not to interfere with injection of the needle. After the injection is complete and during needle withdrawal, the blunting member is advanced to an extended position in which its distal tip protrudes beyond the puncture tip thereby blunting the needle. One drawback of this design is that the blunting member does not protect the needle tip prior to needle insertion. In addition, if during insertion, the health care worker slips and the needle is prematurely removed prior to completing insertion, the blunt does not extend past the needle tip protecting the health care worker from an accidental needle stick.  
           [0007]    The prior art safety catheters all exhibit one or more drawbacks that have thus far limited their usefulness and full acceptance by health-care workers. None of the prior art safety catheters protect the health care clinician during the entire procedure: before the needle is inserted into the patient, during insertion in case of an accidental removal, and during the removal of the needle assembly. What is needed therefore is a safety IV catheter that functions reliably, is easy and inexpensive to manufacture, easy to use, and protects the needle tip throughout its use.  
         SUMMARY OF THE INVENTION  
         [0008]    A catheter assembly for insertion into a vessel of a patient. The catheter assembly includes an elongate hollow tubular catheter having a distal end and a proximal end. The proximal end of the catheter has a hub attached thereto. The catheter assembly further includes a needle assembly having an elongated needle with a sharpened distal end and a proximal end. The needle is disposed within the catheter prior to insertion into a patient with the distal end of the needle being distal to the distal end of the catheter. The catheter assembly also includes a safety assembly. The safety assembly has a first position for protecting the sharpened distal end of the needle, and a second position for exposing the sharpened distal end of the needle. The safety assembly normally being in the first position and being movable to the second position for insertion into the vessel of a patient. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    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:  
         [0010]    [0010]FIG. 1 is a perspective view of the IV catheter assembly of the present invention.  
         [0011]    [0011]FIG. 2 is an exploded view of the IV catheter assembly of the present invention illustrating the elements therein.  
         [0012]    [0012]FIG. 3 is a top view of the IV catheter assembly of the present invention illustrating the blunt extended beyond the needle tip when the buttons are released.  
         [0013]    [0013]FIG. 4 is perspective view of the distal end of IV catheter assembly of the present invention illustrating the blunt extending beyond the needle tip.  
         [0014]    [0014]FIG. 5 is a top view of the IV catheter assembly of the present invention illustrating the blunt retracted within the needle when the buttons are depressed.  
         [0015]    [0015]FIG. 6 is perspective view of the distal end of IV catheter assembly of the present invention illustrating the blunt extending beyond the needle tip.  
         [0016]    [0016]FIG. 7 is a top view of the cam in the present invention.  
         [0017]    [0017]FIG. 8 is a bottom view of the cam in the present invention.  
         [0018]    [0018]FIG. 9 is a side view of the cam in the present invention.  
         [0019]    [0019]FIG. 10 is a side view of the first button in the present invention.  
         [0020]    [0020]FIG. 11 is a side view of the first button in the present invention.  
         [0021]    [0021]FIG. 12 is a cross-section view of the device showing the needle assembly when the buttons are released.  
         [0022]    [0022]FIG. 13 is a cross-section view of the device showing the needle assembly when the buttons are released.  
         [0023]    [0023]FIG. 14 is a perspective view of the blunt assembly in the present invention.  
         [0024]    [0024]FIG. 15 is a cross section view of the IV catheter assembly illustrating the blunt extending beyond the needle tip.  
         [0025]    [0025]FIG. 16 is a cross section view of the IV catheter assembly illustrating the blunt retracted within the needle.  
         [0026]    [0026]FIG. 17 is a perspective view of an alternate embodiment of the IV assembly of the present invention with the blunt extending beyond the needle tip and the buttons released.  
         [0027]    [0027]FIG. 18 is a perspective view of an alternate embodiment of the IV assembly of the present invention with the blunt retracted within the needle and the buttons depressed.  
         [0028]    [0028]FIG. 19 is a top view of an alternate embodiment of the present invention illustrating the blunt extending beyond the needle when the buttons are released.  
         [0029]    [0029]FIG. 20 is a top view of an alternate embodiment of the present invention illustrating the blunt retracted within the needle when the buttons are depressed.  
         [0030]    [0030]FIG. 21 is an exploded view of an alternate embodiment of the present invention.  
         [0031]    [0031]FIG. 22 is a top view of an alternate embodiment of the present invention.  
         [0032]    [0032]FIG. 23 is a top view of an alternate embodiment of the present invention showing the blunt extending beyond the needle tip when the buttons are released.  
         [0033]    [0033]FIG. 24 is a top view of an alternate embodiment of the present invention showing the blunt retracted within the needle when the buttons are depressed. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0034]    As used herein, the term “proximal” refers to a location on the catheter and needle assembly with needle tip protector closest to the clinician using the device and thus furthest from the patient on which the device is used. Conversely, the term “distal” refers to a location farthest from the clinician and closest to the patient.  
         [0035]    As illustrated in FIGS. 1 and 2, IV catheter assembly  2  comprises catheter assembly  4  and needle assembly  20 . Needle assembly  20  further includes blunt or safety assembly  26 . Catheter assembly  4  includes catheter  6  which is a tubular structure having a proximal end  5  and distal end  7 . Proximal end  5  of catheter  6  is fixedly attached to catheter hub  8 . Catheters are well known in the medical art and one of many suitable materials, most of which are flexible thermoplastics, may be selected for use in catheter  6 . Such materials may include, for example, polyurethane or fluorinated ethylene propylene. Catheter hub  8  is a generally tubular structure having an internal cavity in fluid communication with the internal lumen of catheter  6 . Catheter hub  8  may be made from a suitable, rigid medical grade thermoplastic such as, for example, polypropylene or polycarbonate. For illustration purposes catheter hub  8  is shown translucent, though in actual use it may be translucent or opaque. At the proximal end of catheter hub  8  is integrally attached Luer fitting  10 , commonly known in the medical art. Luer fitting  10  provides for secure, leakproof attachment of tubing, syringes, or any of many other medical devices used to infuse or withdraw fluids through catheter assembly  4 .  
         [0036]    Referring again to FIGS.  1 - 6 , needle assembly  20  comprises needle  22 , which is a tubular structure with proximal end  21  and distal end  23 , needle hub  24 , and blunt assembly  26 . Needle  22  which is preferably made of stainless steel has a lumen therethrough created by its inner diameter. Bevel  28  which is located at distal end  23  of needle  22  creates a sharp piercing tip. Needle hub  24 , which is generally a box structure having an internal cavity in fluid communication with the lumen in needle  22 , includes needle holder  30 . Needle holder  30 , which is generally tubular, is integrally attached to the proximal end of cam  40 . The inner surface of needle holder  30  created by its inner diameter is fixedly attached to the proximal end  21  of needle. Needle holder  30  is preferably made of a translucent or transparent generally rigid thermoplastic material such as, for example, polycarbonate. At the most proximal end of the internal cavity in needle hub  24  is fixedly attached porous plug  32 . A flashback chamber  34  is created in the cavity distal to porous plug  32 . Porous plug  32  contains a plurality of microscopic openings which are large enough to permit the passage of air and other gasses but small enough to prevent the passage of blood. Flashback chamber  34  fills with blood upon successful entry of the needle tip into the targeted vein, providing the clinician visual conformation of the correct placement of the needle.  
         [0037]    As shown in FIGS.  7 - 9 , needle hub  24  further includes cam  40 . Cam  40  is generally a box like structure preferably made of a rigid thermoplastic such as, for example, polycarbonate having top  42 , bottom  44 , first side  46 , second side  48 , and hollow  50  therethrough. Cam  40  further includes first eyelet  52 , second eyelet  56 , first hinge  60 , second hinge  62 , first channel  66 , second channel  68 , and cam arm  70 . First eyelet  52 , which is an opening on top  42  of cam  40 , is generally oval shaped having first end  51  and second end  53 . First eyelet  52 , which is angled away from the longitudinal axis such that first end  51  is located above second end  53 , is in fluid communication with hollow  50  of cam  40 . Second eyelet  56 , which is an opening on top  42  of cam  40 , is generally oval shaped having first end  55  and second end  57 . Second eyelet  56 , which is angled away from the longitudinal axis such that first end  55  is located above second end  57 , is in fluid communication with hollow  50  of cam  40 . Cam  40  further includes first hinge  60  and second hinge  64 . First hinge  60  is an arced notch in top  42 , bottom  44 , and first side  46  at the proximal end of cam  40 . First hinge  60  allows first button  80  (shown in FIG. 10) to pivot in and out of cam  40  causing blunt  130  to extend and retract. Second hinge  62  is an arced notch in top  42 , bottom  44 , and second side  48  (not shown but located opposite of first side  46 ) at the proximal end of cam  40  opposite of first hinge  60 . Second hinge  62  allows second button  100  (shown in FIG. 11) to pivot in and out of cam  40  causing blunt  130  to extend and retract. Top  42  of cam  40  includes first channel  66  therein. First channel  66  is a groove in top  42  which runs parallel to the longitudinal axis and plays an integral role in securing blunt  100  over the needle tip, which will be described in more detail later. Bottom  44  of cam  40  includes second channel  68  therein. Second channel  68  is a groove in bottom  44  which runs parallel to the longitudinal axis and plays an integral role in securing blunt  130  over the needle tip, which will be described in more detail later. Cam  40  further includes cam arm  70 . Cam arm  70  is generally rectangular shaped having first cam lock  72  and second cam lock  74  extending laterally therefrom. Cam arm  70  is integrally molded from the middle to the distal end of bottom  44  of cam  40 . Cam arm  70  further includes lip  76  integrally attached to its distal end. Lip  76  plays an important role in securing and releasing blunt assembly  26  so that it may cover and uncover the needle tip of needle  22 . First cam lock  72 , which is generally rectangular, is integrally attached to first wall  71  of cam arm  70  extending laterally therefrom. Second cam lock  74 , which is generally rectangular, is integrally attached to second wall  73  of cam arm  70  extending laterally therefrom. First cam lock  72  and second cam lock  74 , which play an important role in securing blunt  130  beyond the tip of needle  22  when first button  80  and second button  100  are released, will be described in more detail later. At the proximal end of cam  40  is an aperture therethrough. The aperture in cam  40  is in fluid communication with hollow  50  and helps blunt assembly  26  to move proximally and distally within cam  40 .  
         [0038]    As shown in FIGS.  10 - 13 , needle hub  24  further includes first button  80 , second button  100 , first spring  116 , and second spring  118 . First button  80 , which is preferably made of a rigid thermoplastic such as, for example, polycarbonate, includes first button arm  82 , first top wing  84 , and first bottom wing  86 . First button arm  82  is generally a pistol shape and includes first thumb press  81  and first arm wall  83 . First arm wall  83  is integrally attached to first top wing  84  and first bottom wing  86  such that first top wing  84  is indented from the top of first button arm  82  forming first gap  88  and first bottom wing  86  is integrally attached to the bottom of first button arm  82  such that it forms first button surface  89 . As shown in FIGS. 12 and 13, first top wing  84  has first top groove  85  extending diagonally therein. Similarly, first bottom wing  86  has first bottom groove  87  (not shown but directly under first top groove  85 ) extending diagonally therein. Integrally attached to the distal end of first button arm  82  is first button guide  90  and first blunt lock  92 . First button guide  90 , which is generally cylindrical, is integrally attached to the top of first arm wall  83  at the distal end of first button arm  82 . First blunt lock  92 , which is generally cylindrical, is integrally attached to the bottom of first arm wall  83  at the distal end of first button arm  82 . Integrally attached to the proximal end of first button arm  82  is first button pin  94 . First button pin  94 , which is generally cylindrical, is preferably made of a rigid thermoplastic, such as, for example polycarbonate. Second button  100 , which is preferably made of a rigid thermoplastic such as, for example, polycarbonate, includes second button arm  102 , second top wing  104 , and second bottom wing  106 . Second button arm  102  is generally a pistol shape and includes second thumb press  101  and second arm wall  103 . Second arm wall  103  is integrally attached to second top wing  104  and second bottom wing  106  such that second top wing  104  forms second button surface  109  and second bottom wing  106  forms second gap  108 . As shown in FIGS. 12 and 13, second top wing  104  has second top groove  105  extending diagonally therein. Similarly, second bottom wing  106  has second bottom groove  107  (not shown but directly under second top groove  105 ) extending diagonally therein. Integrally attached to the distal end of second button arm  102  is second button guide  110  and second blunt lock  112 . Second button guide  110 , which is generally cylindrical, is integrally attached to the top of second arm wall  103  at the distal end of second button arm  102 . Second blunt lock  112 , which is generally cylindrical, is integrally attached to the bottom of second arm wall  103  at the distal end of second button arm  102 . Integrally attached to the proximal end of second button arm  102  is second button pin  114 . Second button pin  114 , which is generally cylindrical, is preferably made of a rigid thermoplastic, such as, for example polycarbonate. First spring  116 , which is preferably made of flexible polymer such as, for example, polyethylene is generally rectangular having first inner side  115  (not shown). First inner side  115  is fixedly attached to the proximal end of cam  40  and first button arm  82  such that half of first spring  116  resides on first button arm  82  and half resides on cam  40 . Second spring  118 , which is preferably made of flexible polymer such as, for example, polyethylene is generally rectangular having second inner side  117  (not shown). Second inner side  117  is fixedly attached to the proximal end of cam  40  and second button arm  102  such that half of second spring  118  resides on second button arm  102  and half resides on cam  40 .  
         [0039]    Referring now to FIG. 14, blunt assembly  26  includes blunt  130  and blunt holder  132 . Blunt  130  has a proximal end  129  and a distal end  131  and is preferably a hollow tubular structure with a cavity therethrough formed from a single piece of thin, resilient material such as, for example, stainless steel or a polymer. Proximal end  129  of blunt  130  is fixedly attached to blunt holder  132 . Blunt holder  132 , which has a cavity therethrough in fluid communication with the cavity of blunt  130 , is generally a tubular structure having a conical shaped distal end. Blunt holder  132  is preferably made of a translucent or transparent generally rigid thermoplastic material such as, for example, polycarbonate. Blunt assembly  26  further includes first channel pin  134  and second channel pin  136 . First channel pin  134 , which is generally cylindrical, is preferably made from a rigid thermoplastic such as, for example, polycarbonate. First channel pin  134  extends laterally from blunt holder  132  and plays an integral role in preventing blunt assembly  26  from moving axially in cam  40 . Second channel pin  136 , which is generally cylindrical, is preferably made from a rigid thermoplastic such as, for example, polycarbonate. Second channel pin  136  extends laterally from blunt holder  132  and plays an integral role in preventing blunt assembly  26  from moving axially in cam  40 . Blunt assembly  26  plays an important role in protecting needle  22  and will be described in more detail later.  
         [0040]    Referring now to FIGS. 15 and 16, it can understood how blunt assembly  26  is assembled to cam  40  and needle  22 . The distal end of blunt  130  is inserted through the opening on the proximal end of cam  40  and then advanced through hollow  50  and into the lumen in needle  22 , moving proximal to distal, until blunt  130  extends beyond the needle tip as shown in FIG. 15. During insertion of blunt  130 , first channel pin  134  and second channel pin  136  are positioned such that first channel pin  134  is located in first channel  66  and second channel pin  136  is located in second channel  68  of cam  40 . Placing first channel pin  134  in first channel  66  and second channel pin  136  in second channel  68  prevents axial movement of blunt assembly  26  in cam  40  during use.  
         [0041]    As shown in FIGS.  1 - 3 , after blunt assembly  26  is assembled to cam  40  and needle  22 , first button  80 , second button  100 , first spring  116 , and second spring  118  are assembled to cam  40  to form needle assembly  20 . First button pin  94  is snapped into first hinge  60  such that first button guide  90  resides in first eyelet  52  and first blunt lock  92  resides in first cam lock  72 . Second button pin  114  is snapped into second hinge  68  such that second button guide  10  resides in second eyelet  56  and second blunt lock  112  resides in second cam lock  74 . As shown in FIGS. 12 and 13, second top wing  104  is located above first top wing  84  and second bottom wing  106  is above first bottom wing  86  after first button  80  and second button  100  are connected to cam  40 . In addition, first top groove  85  and second top groove  105  have first cannel pin  134  therebetween. Similarly, first bottom groove  87  and second bottom groove  107  have second cannel pin  136  therebetween. Having first channel pin  134  and second channel pin  136  in the grooves of the button wings creates a stopping mechanism which will not allow blunt assembly  26  from completely withdrawing from cam  40 . First spring  116  can then be fixedly attached to first button  80  at the proximal end of cam  40 . Similarly, second spring  118  can then be fixedly attached to second button  100  at the proximal end of cam  40 . When first button  80  and second button  100  are biased outward by first spring  116  and second spring  118 , as shown in FIGS. 3 and 4, blunt  130  extends beyond the needle tip in order to prevent a needle stick. Blunt  130  stays extended beyond the needle tip until first button  80  and second button  100  are depressed. Once depressed, first button  80  and second button  100  will retract blunt  130  behind the needle tip, as shown in FIGS. 5 and 6. Then when pressure is removed from first button  80  and second button  100 , first spring  116  and second spring  118  will reset first button  80  and second button  100  to its biased outward position and blunt  130  will extend again to protect the needle tip.  
         [0042]    As shown in FIG. 1, needle assembly  24 , including blunt  130 , is assembled into catheter assembly  4 . Distal end  23  of needle  22 , which has blunt  130  extending therefrom to protect the needle tip, extends distally from distal end  7  of catheter  6 . Blunt  130  is retained past the needle tip by first blunt lock  92  locking in first cam lock  72  on cam arm  70  and second blunt lock  112  locking into second cam lock  74  on cam arm  70 , while the distal end of needle  22  and blunt  130  is being inserted into catheter  6 . Needle assembly  20  is secured onto luer fitting  10  of catheter hub  30  so that lip  76  is biased away from cam  40 , which unlocks first button  80  and second button  100  allowing blunt  130  to be retracted within needle  22  once first button  80  and second button  100  are depressed.  
         [0043]    Now, it will be described how in actual clinical use, the IV catheter assembly  2  of the present invention functions. The clinician begins by connecting the catheter assembly  4  to the needle assembly  20  such that luer fitting  10  is biased against lip  76  of cam  40 . Securing luer fitting  10  such that it is biased against lip  72  causes cam arm  70  to be forced away from cam  40  releasing first cam lock  72  and second cam lock  74  from first blunt lock  92  and second blunt lock  112 . Attaching the catheter assembly to the needle hub moves the blunt to a first position wherein the distal end of the blunt is distal to the distal end of the needle and enables the clinician to squeeze the buttons or actuator. The clinician then depresses and holds down first button  80  and second button  100 , which pivot into cam  40 . While first button  80  and second button  100  are being depressed, first top groove  85  and second top groove  105  and first bottom groove  87  and second groove  107 , which have first channel pin  134  and second channel pin  136  residing therein respectively, force blunt assembly  26  proximally retracting blunt  130  within needle  22  as shown in FIG. 16. Depressing the buttons causes the blunt to move proximally to a second position, thereby exposing the needle tip. The distal end of needle  38  which extends just past the distal end of catheter  6  is then inserted into the patient&#39;s vein. After observing blood in flashback chamber  34 , the clinician grasps needle hub  24 , and catheter assembly  4  alone is moved distally into the vein. The clinician applies slight pressure to the insertion site to hold catheter assembly  4  secure. Then, the clinician grasps needle hub  24  and begins withdrawal of needle assembly  20  from catheter assembly  4 . During this process, blunt  130  remains secure inside needle  22  until first button  80  and second button  100  are released. When first button  80  and second button  100  are released, first spring  116  and second spring  118  return first button  80  and second button  100  to its outward position causing first top groove  85  and second top groove  105  to move first channel pin  134  and first bottom groove  87  and second bottom groove  107  to move second channel pin  136  distally along with blunt assembly  26  as shown in FIG. 15. The distal movement of blunt assembly  26  causes blunt  130  to extend distally past the tip of needle  22 . When the clinician releases the buttons, the blunt moves distally covering the needle tip. When first button  80  and second button  100  are completely released, first spring  116  and second spring  118  hold the buttons in place while the first blunt lock  92  and second blunt lock  112  secure into first cam lock  72  and second cam lock  74 , since cam arm  70  has been released from its biased position on luer fitting  10  of catheter  6 . Securing first blunt lock  92  and second blunt lock  112  into first cam lock  72  and second cam lock  74  prevents first button  80  and second button  100  from being depressed so that the needle tip is exposed. Needle assembly  20  is now removed entirely from catheter assembly  4 , with the needle tip covered by blunt  130  of the present invention. Removing the catheter from the needle assembly causes the blunt to lock beyond the needle tip protecting the clinician from an accidental needle stick. In addition, if during the insertion of IV catheter assembly  2 , the patient suddenly moves before the insertion is complete, the clinician can release first button  80  and second button  100 . When first button  80  and second button  100  are released, first spring  116  and second spring  118  return first button  80  and second button  100  to its outward position causing first top groove  85  and second top groove  105  to move first channel pin  134  and first bottom groove  87  and second bottom groove  107  to move second channel pin  136  distally along with blunt assembly  26  as shown in FIG. 15. The distal movement of blunt assembly  26  causes blunt  130  to extend distally past the needle tip of needle  22  protecting the clinician during use of an accidental needle stick.  
         [0044]    A first alternate embodiment of the present invention is shown in FIGS.  17 - 20 . Needle assembly  220 , similar to needle assembly  20 , includes cam  240 . Cam  240  includes first hinge slot  260  and second hinge slot  262  therein at its proximal end, which replace first hinge  60  and second hinge  62 . First hinge slot  260 , which extends perpendicular to the longitudinal axis of catheter assembly  2 , is generally an oval shaped opening in top  242  and bottom  244  and includes first button pin  294  therein. Similarly, second hinge slot  262 , which extends perpendicular to the longitudinal axis of catheter assembly  202 , is generally an oval shaped opening in top  242  and bottom  244  and includes first button pin  314  therein. Cam  240  further includes first eyelet  252  and second eyelet  256  therein at its distal end. First eyelet  252  and second eyelet  256 , similar to first eyelet  52  and second eyelet  56 , are generally oval shaped openings in top  242  that extend perpendicular to the longitudinal axis of catheter assembly  202 . First eyelet  252  has first button guide  290  of first button  280  residing therein. Similarly, second eyelet  256  has second button guide  310  of second button  300  residing therein. First hinge slot  260  and second hinge slot  262  allow first button  280  and second button  300  respectively to slide rather than pivot into cam  240 .  
         [0045]    A second alternate embodiment of the present invention is shown in FIGS.  21 - 24 . Needle assembly  220 , similar to needle assembly  20 , includes cam  440 , first button  480 , and second button  500 . Cam  440  includes first cam stop  580  and second cam stop  582  at its proximal end. First cam stop  580  and second cam stop  582  are flat surfaces in cam  440  which prevents blunt  130  from retracting proximally and exposing needle  422  when first button  480  and second button  500  are released. Cam  440  further includes first eyelet  452  and second eyelet  456 . First eyelet  452 , which is an opening on top  442  and bottom  444  of cam  440 , is generally oval shaped having first end  451  and second end  453 . First eyelet  452 , which is angled away from the longitudinal axis such that first end  451  is located above second end  453 , is in fluid communication with hollow  450  of cam  440  and has first button pin  490  therein. Second eyelet  456 , which is an opening on top  442  of cam  440 , is generally oval shaped having first end  455  and second end  457 . Second eyelet  456 , which is angled away from the longitudinal axis such that first end  455  is located above second end  457 , is in fluid communication with hollow  450  of cam  440  and has second button pin  510  therein. First button  480  is generally a semi-circular thin wireform preferably made of a spring-like plastic, such as, for example polycarbonate. Integrally attached to the distal end of first button  480  is first button guide  490 . First button guide  490 , which is generally cylindrical, resides in first eyelet  452  of cam  440  and helps guide first button  480  into cam  440  when it is depressed and released during the procedure. Integrally attached to the proximal end of first button  480  is first blunt lock  492 . First blunt lock  492  is generally a rectangular block which helps secure blunt  530  over needle  422 . Second button  500  is generally a semi-circular thin wireform preferably made of a spring-like plastic, such as, for example polycarbonate. Integrally attached to the distal end of second button  500  is second button guide  510 . Second button guide  510 , which is generally cylindrical, resides in second eyelet  456  of cam  440  and helps guide second button  500  into cam  440  when it is depressed and released during the procedure. Integrally attached to the proximal end of second button  510  is second blunt lock  512 . Second blunt lock  512  is generally a rectangular block which helps secure blunt  530  over needle  422 . The proximal ends of first button  480  and second button  500  are fixedly attached to the distal end of blunt holder  532  as shown in FIG. 21. When first button  480  and second button  500  are depressed, first blunt lock  492  and second blunt lock  512  are released from first blunt stop  580  and second blunt stop  582  respectively. After the release of first blunt lock  492  and second blunt lock  512 , blunt  530  and blunt holder  532  are moved proximally exposing needle  422 . When first button  480  and second button  500  are released, blunt  530  and blunt holder  532  slide distally so that blunt  530  extends beyond needle  122  protecting the user from an accidental needle stick.  
         [0046]    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. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. For example, as would be apparent to those skilled in the art, the disclosures herein have equal application in robotic-assisted surgery. In addition, it should be understood that every structure described above has a function and such structure can be referred to as a means for performing that function. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.