Abstract:
A plurality of different vascular access assemblies are described which protect a clinician from accidental needle stick injury upon withdrawal of a needle from a catheter assembly. Each of the vascular access assemblies include a safety device for guarding the needle tip of the needle upon withdrawal of a needle from the catheter assembly.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority under 35 U.S.C. §119 to co-pending U.S. Provisional Application Ser. No. 61/511,187 entitled VASCULAR ACCESS ASSEMBLY WITH SAFETY DEVICE, filed Jul. 25, 2011, the entire contents of which is incorporated herein by reference for all purposes. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates to vascular access assemblies, and more particularly to vascular access assemblies including a safety device for protecting a clinician from accidental needle stick injuries. 
         [0004]    2. Background 
         [0005]    Vascular access assemblies are utilized in a variety of medical applications for supplying or withdrawing fluid to or from a body vessel. Generally, vascular access assemblies include an external cannula for indwelling in a blood vessel of a patient and an internal needle that is inserted into the external cannula to facilitate piercing of the blood vessel of the patient. In operation of the access assembly, the internal needle is inserted into the external cannula such that the tip portion of the internal needle protrudes from a tip portion of the external cannula. Next, the internal needle is manipulated to pierce a blood vessel and to position the external cannula within the blood vessel. While the external cannula is positioned within in the blood vessel, the internal needle is withdrawn from the external cannula leaving the external cannula positioned within the blood vessel. In this position, a medical device can be connected to the rear end portion of the external cannula using, for example, a luer connector, to facilitate the supply and withdrawal of fluid, such as blood, medication and/or nutrients to or from the body vessel. 
         [0006]    After the internal needle is withdrawn from the external cannula, the exposed needle tip of the internal needle creates a danger of accidental needle stick injury which can leave a clinician vulnerable to the transmission of various blood-borne pathogens, such as HIV and hepatitis. While needle tip protectors have been developed to protect the clinician from needle stick injuries, the cost, ease of use, and effectiveness of these needle tip protectors leaves room for improvement. 
         [0007]    Accordingly, it would be beneficial to provide a vascular access assembly which is easily activated by a clinician, effectively protects a clinician from accidental needle stick injury and is economical to produce. 
       SUMMARY 
       [0008]    A vascular access assembly and safety device is disclosed that includes a catheter assembly including a catheter hub and a catheter tube extending distally from the catheter hub, a needle assembly including a needle having a needle tip, and a safety device including a housing and a safety clip. The housing defines a cavity and proximal and distal openings through endwalls of the housing and the safety clip is formed of a resilient material and is supported within the cavity of the housing. The safety clip defines a distal opening, a central opening and a proximal opening which are aligned with each other and with the proximal and distal openings of the housing in a first deformed position of the safety clip to slidably receive the needle. The needle retains the safety clip in the first deformed position. The housing defines a ramp positioned between the endwalls of the housing and against which the safety clip abuts when the safety clip is in the first deformed position. When the needle is withdrawn from the catheter assembly such that the needle tip passes through the distal opening of the safety clip, the safety clip is configured to ride up the ramp and move to a second position to obstruct distal movement of the needle tip into the distal opening of the housing. 
         [0009]    In one embodiment, a distal end of the safety clip includes a hook portion which is positioned to engage the catheter hub when the safety clip is in the first deformed position to releasably secure the safety device to the catheter hub. The hook portion is movable to a position disengaged from the catheter hub when the safety clip moves to the second position. 
         [0010]    In one embodiment, the safety clip is configured to move to a third position when the needle tip is withdrawn through the central opening of the safety clip to further obstruct distal movement of the needle tip through the distal opening. In the third position, the orientation of the proximal opening is such that the clip binds with the needle adjacent the third opening to obstruct proximal movement of the needle in relation to the safety clip. 
         [0011]    In another embodiment, vascular access assembly and safety device includes a catheter assembly including a catheter hub and a catheter tube extending distally from the catheter hub, a needle assembly including a needle hub and a needle extending distally from the needle hub, and a safety device including a housing defining a cavity and a safety clip supported within the cavity. The housing includes a proximal opening dimensioned to slidably receive the needle and an open distal end. The safety clip has a pair of resilient legs which are configured to releasably engage a proximal end of the catheter hub in a deformed first position of the safety clip to releasably secure the safety device to the catheter assembly. The safety clip is movable to a second non-deformed position, wherein the resilient legs block distal movement of the needle from within the housing. 
         [0012]    In one embodiment, each resilient leg of the pair of resilient legs includes a protrusion which is configured to be received in a recess formed in the catheter hub to releasably secure the safety device to the catheter hub. The safety is manually releasable from engagement with the catheter hub. 
         [0013]    The safety clip may include a proximal wall defining an opening for slidably receiving the needle. The needle defines an enlarged diameter portion wherein the outer diameter of the enlarged diameter portion is greater than the inside diameter of the opening in the proximal wall of the safety clip such that withdrawal of the needle through the proximal opening of the safety clip is prevented. 
         [0014]    In one embodiment, each of the resilient legs of the pair of resilient legs includes a radial portion. The radial portions are dimensioned to obstruct distal movement of the needle when the safety clip is disengaged from the catheter hub and moves from the first deformed position to the second non-deformed position. 
         [0015]    In another embodiment, the vascular access assembly and safety device includes a catheter assembly including a catheter hub and a catheter tube extending distally from the catheter hub, a needle assembly including a needle hub and a needle extending distally from the needle hub, the needle including a needle tip, and a safety device including a housing defining a cavity and a safety clip positioned within the cavity. The housing defines a proximal opening and a distal opening. The safety clip is formed from a resilient material and has a U-shaped configuration including a first leg positioned adjacent an inner wall of the housing and a second leg supporting a tab. In an assembled state, the needle extends through the distal and proximal openings of the housing of the safety device and through the catheter assembly and the safety clip is compressed between the inner wall of the housing and the tab slidably engages the needle. Upon withdrawal of the needle tip into the housing of the safety device and proximally of the tab of the safety clip, the safety clip moves to a non-compressed position such that the tab obstructs distal movement of the needle into the distal opening of the housing. 
         [0016]    In one embodiment, the needle includes an enlarged diameter portion and a bushing is slidably supported on the needle proximally of the enlarged diameter portion. The inner diameter of the bushing is smaller than the outer diameter of the enlarged diameter portion, and the outer diameter of the bushing is larger than the inner diameter of the proximal opening of the housing of the safety device to prevent withdrawal of the needle tip from the proximal opening. 
         [0017]    The housing may include a resilient arm which includes a projection which is received in a recess formed in the catheter hub to releasably secure the catheter hub to the safety device. 
         [0018]    In one embodiment, the tab if the safety clip includes a rounded end portion positioned to slidably engage the needle in the assembled state. 
         [0019]    In another embodiment, the vascular access assembly and safety device includes a needle having a needle tip and an enlarged diameter portion, and the safety device includes a housing defining a throughbore and having a distal open end and a proximal opening dimensioned to slidably receive the needle. The housing includes a resilient arm including a radially extending protrusion configured to releasably engage a catheter hub. A first disk is fixedly supported within the housing and defines a recess defined by a plurality of proximally extending fingers. The proximally extending fingers define a central opening and are configured to deflect inwardly to facilitate passage of the enlarged diameter portion of the needle in a proximal direction through the central opening of the disk but to prevent passage of the enlarged diameter portion of the needle through the central opening of the disk in a distal direction. 
         [0020]    In one embodiment, the safety device recess is frusto-conical or spherical. 
         [0021]    The safety device may further include a second disk supported proximally of the first disk. The second disk includes a plurality of distally extending fingers that define a central opening and are configured to prevent passage of the enlarged diameter portion of a needle in the proximal direction. 
         [0022]    In another embodiment, the vascular access assembly and safety device includes a needle including an enlarged diameter portion and a needle tip, a housing defining a cavity having an open distal end and a proximal opening, a large diameter portion, a small diameter portion, a distally facing ramp portion positioned between the large diameter portion and the small diameter portion, and a proximally facing shoulder positioned adjacent a proximal end of the ramp portion. A clip which is formed of a resilient material and has a proximal wall defining an opening for slidably receiving a needle is provided. A leg extends radially outwardly and distally from each end of the proximal wall. Each leg includes a radially and proximally extending portion. At least one of the radially and proximally extending portions includes a cutout for slidably receiving the needle. In an advanced position of the needle, the clip is positioned about the needle in the large diameter portion of the housing and the needle extends distally from the open distal end of the housing. Upon withdrawal of the needle tip into the housing, the enlarged diameter portion of the needle engages the radially and proximally extending portions to deflect the radially and proximally extending portions inwardly to allow passage of the enlarged diameter portion of the needle past the radially and proximally extending portions and into engagement with the proximal wall. Further withdrawal of the needle effects movement of the clip over the distally facing ramp portion, past the proximally facing shoulder and into the small diameter portion of the cavity. The enlarged diameter portion of the needle has a diameter larger than the opening in the proximal wall to prevent proximal movement of the needle tip from a proximal end of the housing. The small diameter portion of the cavity of the housing prevents outward deflection of the radially and proximally extending portions of the clip and the proximally facing shoulder prevents distal movement of the clip from the small diameter portion to prevent distal movement of the needle tip from the cavity of the housing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]    Various embodiments of the presently disclosed vascular access assembly and safety device will be described herein with references to the accompanying drawings, wherein: 
           [0024]      FIG. 1  is a side cross-sectional view of one embodiment of the presently disclosed vascular access assembly and safety device with the needle in an advanced position; 
           [0025]      FIG. 2  is an enlarged view of the safety device and proximal end of the catheter hub of the vascular access assembly shown in  FIG. 1  with the needle tip about to enter the housing of the safety device; 
           [0026]      FIG. 3  is a side cross-sectional view of the vascular access assembly and safety device shown in  FIG. 2  with the needle withdrawn into the housing of the safety device through the distal opening of the safety clip; 
           [0027]      FIG. 4  is a side cross-sectional view of the vascular access assembly and safety device shown in  FIG. 2  with the needle tip withdrawn into the housing of the safety device through the central opening of the safety clip; 
           [0028]      FIG. 5  is an enlarged view of the safety device and proximal end of the catheter hub of the vascular access assembly and safety device shown in  FIG. 1  after the needle tip has been withdrawn into housing of the safety device and through the distal and central openings of the safety clip; 
           [0029]      FIG. 6  is a side cross-sectional view of another embodiment of the presently disclosed vascular access assembly and safety device in an assembled state; 
           [0030]      FIG. 7  is an enlarged side cross-sectional view of the vascular access assembly and safety device shown in  FIG. 6 ; 
           [0031]      FIG. 8  is a side, cross-sectional view of the safety device and needle shown in  FIG. 7  with the safety clip disengaged from the catheter hub; 
           [0032]      FIG. 9  is a side view of another embodiment of the presently disclosed vascular access assembly and safety device in an assembled state; 
           [0033]      FIG. 10  is a cutaway view through the housing of the safety device looking proximally into the housing; 
           [0034]      FIG. 11  is a perspective view with parts separated of the vascular access assembly and safety device shown in  FIG. 9  with the needle tip withdrawn into the housing of the safety device; 
           [0035]      FIG. 12  is an enlarged view of the safety device shown in  FIG. 11  supported on the distal end of the needle with the distal end of the needle and safety clip shown in phantom; 
           [0036]      FIG. 13  is a perspective view of another embodiment of a safety device for use with a vascular access assembly; 
           [0037]      FIG. 14  is a side cross-sectional view of the safety device shown in  FIG. 13  with a needle of the vascular access assembly extending through the safety device; 
           [0038]      FIG. 15A  is a top view of a disk of the safety device shown in  FIG. 14 ; 
           [0039]      FIG. 15B  is a cross-sectional view taken along section line  15 B- 15 B of  FIG. 15A ; 
           [0040]      FIG. 16A  is a top view of another embodiment of a disk of the safety device shown in  FIG. 14 ; 
           [0041]      FIG. 16B  is a cross-sectional view taken along section lines  16 B- 16 B of  FIG. 16A ; 
           [0042]      FIG. 17  is a side cross-sectional view of an alternate embodiment of the safety device shown in  FIG. 13  with a needle of a vascular access assembly extending therethrough; 
           [0043]      FIG. 18A  is a side cross-sectional view of another embodiment of the safety device shown in  FIG. 13  with the needle of the vascular access assembly extending through the housing of the safety device; 
           [0044]      FIG. 18B  is a side cross-sectional view of the safety device shown in  FIG. 18A  with the tip of the needle withdrawn into the housing of the safety device; 
           [0045]      FIG. 19  is a side perspective view of the clip of the safety device shown in  FIG. 18A  supported on the needle of the vascular access assembly; 
           [0046]      FIG. 20  is a side view of another embodiment of the presently disclosed vascular access assembly and safety device in an assembled state; 
           [0047]      FIG. 21  is a side view of the vascular access assembly and safety device shown in  FIG. 20  in an assembled state with the biasing member and needle in the housing of the safety device shown in phantom; 
           [0048]      FIG. 22  is a side partial cross-sectional view of the safety device and needle assembly of the vascular access assembly shown in  FIG. 20  with the needle tip of the needle assembly withdrawn into the housing of the safety device; and 
           [0049]      FIG. 23  is an enlarged view of the safety device supported on the distal end of the needle as shown in  FIG. 22 . 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0050]    Embodiments of the presently disclosed vascular access assembly and safety device will now be described in detail with reference to the drawings wherein like reference numerals designate identical or corresponding elements in each of the several views. In this description, the term “proximal” is generally used to refer to the portion of the device that is closer to a clinician, while the term “distal” is generally used to refer to the portion of the device that is farther from the clinician. As used herein, the term “patient” should be understood as referring to a human patient or other animal, and the term “clinician” should be understood as referring to a doctor, nurse or other care provider and may include support personnel. 
         [0051]      FIGS. 1-3  illustrate one embodiment of the presently disclosed vascular access assembly and safety device, hereinafter access assembly, shown generally as  10 . Access assembly  10  comprises a catheter assembly including a catheter hub  12  ( FIG. 1 ) and a catheter tube  12   a , a safety device  13  having a housing  14  and a safety clip  15  supported within the housing  14 , and a needle assembly including a needle  18  and a needle hub (not shown). In a ready to use position, shown in  FIG. 1 , the needle  18  extends from the needle hub, through distal and proximal openings  14   a  and  14   b  ( FIG. 2 ), respectively, in the safety device housing  14 , and through catheter hub  12  and catheter tube  12   a  of the catheter assembly. 
         [0052]    As shown in  FIGS. 1-3 , the safety clip  15  is formed from a substantially flat, resilient member which includes a distal opening  20 , a central opening  21 , and a proximal opening  22 . In one embodiment, the safety clip  15  is formed from spring steel. Alternately, other resilient materials can be used to form the safety clip  15 . In the ready-to-use position or assembled state, the needle  18  is positioned to extend through the distal, central, and proximal openings  20 - 22 , respectively, of the safety clip  15 , to retain the safety clip  15  in a curved, deformed configuration within the housing  14 . In this configuration, holes  20 - 22  of safety clip  15  are aligned with distal and proximal openings  14   a  and  14   b  of safety device housing  14  and oriented to allow the needle to be withdrawn from the catheter assembly through the safety clip  15 . 
         [0053]    A distal end of the safety clip  15  includes a hook portion  24  which extends through an opening  26  in the housing  14 . In the ready-to-use position of the access assembly  10 , the proximal, central, and distal openings  20 - 22  of the safety clip  15  are aligned with the openings  14   a  and  14   b  of the housing  14  and the hook portion  24  of safety clip  15  is engaged with a luer connector  12   a  of the catheter hub  12  to releasably secure the housing  14  to the proximal end of the catheter hub  12 . In addition, a proximal end  15   b  of safety clip  15  abuts endwall  50  of housing  14 . See  FIG. 5 . 
         [0054]    Referring to  FIG. 2 , an inner wall of housing  14  defines a ramp  30  which abuts a portion  15   a  of safety clip  15  between distal and central openings  20  and  21 . The ramp  30  prevents distal expansion of safety clip  15  in the ready-to-use position of the assembly  10  to retain hook portion  24  of safety clip  15  in contact with catheter hub  12 . 
         [0055]    Referring to  FIGS. 3-5 , when the needle  18  is retracted such that the needle tip  18   a  passes through distal opening  20  of safety clip  15 , the distal end of the safety clip  15 , which is no longer constrained by the needle  18 , expands outwardly and upwardly within housing  14 . When this occurs, the portion  15   a  of safety clip  15  defined between distal and central openings  20  and  21  rides up ramp  30  of housing  14  to lift hook portion  24  from engagement with catheter hub  12  and to partially cover or obstruct distal opening  14   a  of housing  14 . See  FIG. 3 . This prevents distal advancement of needle  18  from housing  14  of safety clip  15 . Concurrently, safety clip  15  tends to flatten. As the tip  18   a  of the needle  18  is withdrawn through central opening  21 , safety clip  15  flattens to change the orientation of opening  22  with respect to needle  18 . This change in orientation causes proximal opening  22  of safety clip  15  to tilt with respect to the longitudinal axis of needle  18  such that the edge of clip  15  defining opening  22  engages needle  18  to prevent further retraction of needle  18  through housing  14 . Thus, tip  18   a  of needle  18  is safely retained within housing  14  of the safety device  15 . See  FIG. 5 . As shown in  FIGS. 4 and 5 , when needle tip  18   a  passes through central opening  21  of safety clip  15 , safety clip  15  expands outwardly and upwardly within housing  14  to block distal opening  14   a.    
         [0056]      FIGS. 6-8  illustrate another embodiment of the presently disclosed access assembly shown generally as  100 . Access assembly  100  includes a catheter assembly having a catheter hub  112  and a catheter tube  112   a  extending distally of the catheter hub  112 , a safety device  113  including a housing  114  and a safety clip  116 , and a needle assembly including a needle  118  and a needle hub  120  supporting a proximal end of the needle  118 . The needle  118  includes a sharpened tip  118   a . In a ready-to-use position, the needle  118  extends through the safety device  113  and the catheter assembly such that the tip  118   a  of needle  118  extends from a distal end of the catheter tube  112   a.    
         [0057]    Referring to  FIGS. 6 and 7 , safety clip  116  is received within a cavity  114   a  housing  114 . Housing  114  includes a proximal wall  122  defining an opening  124  for slidably receiving needle  118  and an open distal end  126 . A pair of spaced posts  130  are formed in housing  114  for fixedly locating the safety clip  116  within the housing  114  as will be discussed below. 
         [0058]    Safety clip  116  includes a proximal wall  136  defining an opening  136   a  for slidably receiving the needle  118 . A resilient leg  140  extends distally from each end of proximal wall  136 . The distal end of each leg  140  supports a substantially L-shaped member  142  ( FIG. 8 ) which includes a longitudinal portion  142   a  and a radial portion  142   b  ( FIG. 7 ). The longitudinal portion  142   a  of each L-shaped member  142  includes a protrusion  144  which is positioned to be received in a recess  146  formed in a proximal end of catheter hub  112  to releasably secure catheter hub  112  to safety clip  116  when the access assembly  100  is in the ready-to-use position. In the ready-to-use position of access assembly  100 , members  142  are spaced from needle  118  to minimize drag on the needle  118 . The radial portions  142   b  are dimensioned to overlap ( FIG. 8 ) when the needle tip  118   a  of needle  118  is retracted into housing  114  of safety device  113  as will be discussed below. Alternately, the radial portions  142   b  need not overlap but should be configured to prevent distal movement of the needle  118  when the safety clip  116  moves to a non-deformed configuration. 
         [0059]    Referring to  FIG. 8 , needle  118  includes an enlarged diameter portion  150 , which may be formed by providing a crimp in needle  118 . Alternatively, enlarged diameter portion  150  may be formed in a variety of different ways including providing an annular protrusion about needle  118  by welding or the like. Enlarged diameter portion  150  has an outer diameter larger than the inner diameter of opening  136   a  formed in proximal wall  136  of clip  116 . When needle  118  is withdrawn into safety clip housing  114 , enlarged diameter portion  150  engages proximal wall  136  and pulls safety clip  116  (and housing  114 ) proximally in relation to catheter hub  112  ( FIG. 7 ), which is held stationary by a clinician. As clip  116  is pulled proximally in relation to catheter hub  112 , resilient legs  140  of clip  116  flex outwardly as protrusions  144  are manually disengaged from recesses  146  ( FIG. 6 ) of catheter hub  112 . When legs  140  move proximally over the proximal end of catheter hub  112 , legs  140  return to their non-deformed configuration, wherein radial portions  142   b  of legs  140  overlap and/or block distal movement of needle  118 . 
         [0060]      FIGS. 9-12  illustrate another embodiment of the presently disclosed access assembly shown generally as  200 . Access assembly  200  comprises a catheter assembly including a catheter hub  212  and a catheter tube  212   a , a safety device  213  including a housing  214  and a safety clip  216 , and a needle assembly  217  including a needle  218  and a needle hub  220 . Housing  214  defines a distal opening  238  and a proximal opening  254 . In the ready-to-use position of access assembly  200 , needle  218  extends through housing  214  of safety device  213  and catheter hub  212  of catheter assembly such that a needle tip  218   a  of needle  218  extends from a distal end of the catheter tube  212   a  ( FIG. 9 ). 
         [0061]    Safety clip  216  is supported in housing  214  and has a curved U-shaped configuration ( FIG. 10 ) having a first leg  216   a  and a second leg  216   b . In the ready-to-use position, the first leg  216   a  is positioned adjacent an inner wall of housing  214  and the second leg  216   b  is positioned between the first leg  216   a  and the needle  218 . Alternately, other configurations are envisioned. Safety clip  216  is formed from a resilient material such as spring steel and includes a radially extending tab  226  supported on second leg  216   b . In the ready-to-use position of access assembly  200 , the second leg  216   b  is deflected towards the first leg  216  by engagement of radially extending tab  226  with needle  218 . More specifically, the safety clip  216  is compressed between an inner wall of housing  214  and the needle  218  via engagement of tab  226  with needle  218 . In one embodiment, the tab  226  includes rounded end portion  226   a  ( FIG. 12 ) positioned to slidably engage the needle  218 . 
         [0062]    Housing  214  of safety device  213  includes a resilient arm  240  having a distal projection  240   a  which is received in a recess  242  formed in an outer wall of catheter hub  212  to releasably secure the safety device  216  to the catheter hub  212 . See  FIG. 11 . 
         [0063]    Referring to  FIGS. 11 and 12 , needle  218  includes an enlarged diameter portion  250 . In addition, a bushing  252  is slidably positioned about needle  218  proximally of enlarged diameter portion  250 . Bushing  252  has an inside diameter smaller than the outside diameter of enlarged diameter portion  250  and an outside diameter which is larger than the inside diameter of the opening  254  in the proximal end of housing  214 . When the needle  218  is retracted into housing  214  of safety clip  216  and needle tip  218   a  passes proximally of radially extending tab  226 , second leg  216   b  of clip  216  moves towards a non-deformed or non-compressed position wherein tab  226  moves to a position in front of and distally of needle tip  218   a  to prevent distal movement of needle tip  218  from housing  214 . See  FIG. 12 . Proximal retraction of needle tip  218   a  from housing  214  is prevented by engagement of enlarged diameter portion  250  of needle  218  with bushing  252  and subsequently, by engagement of bushing  252  with a proximal wall  260  of housing  214 . See  FIG. 12 . 
         [0064]      FIGS. 13-15B  illustrate an alternate embodiment of the presently disclosed safety device shown generally as  313 . Safety device  313  includes a housing  314  having a distal open end  314   a  and a proximal opening  314   b  ( FIG. 14 ). Housing  314  defines a throughbore  316  for slidably receiving a needle  318  having a sharpened tip  318   a  and an enlarged diameter portion  318   b . A bushing  320  is positioned about the needle  318  at a location proximal of the enlarged diameter portion  318   b . The bushing  320  has an inside diameter smaller than the outside diameter of the enlarged diameter portion  318   b , and an outside diameter portion larger than the inside diameter portion of the proximal opening  314   b  of housing  314 . A disk  330  includes a plurality of proximally angled spring fingers  332  ( FIGS. 15A-15B ) positioned about a central opening  334  and is secured to an inner wall of housing  314 . 
         [0065]    In use, due to the orientation of spring fingers  332 , when needle  318  is retracted within housing  314 , fingers  332  will deflect inwardly upon engagement with enlarged diameter portion  318   b  of needle  318  to allow enlarged diameter portion  318   b  to pass through central opening  334  of disk  330 . In this position, with enlarged diameter portion  318   b  positioned between disk  330  and bushing  320 , the needle tip  318   a  is positioned safely within housing  314 . Continued distal movement of needle  318  with respect to housing  314  is prevented by engagement of enlarged diameter portion  318   b  of needle  318  with fingers  332  of disk  330  and continued proximal movement or withdrawal of needle  318  from housing  314  is prevented by engagement of enlarged diameter portion  318   b  of needle  318  with bushing  320  and subsequently by engagement of bushing  320  with a proximal wall  340  of housing  314 . 
         [0066]    Referring to  FIGS. 15A-15B , disk  330  may be formed from a resilient material such as spring steel. In one embodiment, fingers  332  of disk  330  are planar and define a frusto-conical recess. In an alternative embodiment, such as shown in  FIGS. 16A-16B , disk  330 ′ and fingers  332 ′ define a spherical recess  333 ′ and disk  330 ′ includes an annular sidewall  340 ′ positioned about disk  330 ′. 
         [0067]    Although not discussed in detail herein, housing  314  supports a resilient arm  350  including a protrusion  350   a  for releasably engaging a catheter hub (not shown) in a manner similar to that described above with respect to resilient arm  240  and catheter hub  212 . The resilient arm  350  is spaced outwardly of and extends substantially parallel to housing  314   
         [0068]    In another alternative embodiment of the presently disclosed safety device shown generally in  FIG. 17  as  413 , two disks  430   a  and  430   b  are mounted in housing  414 . Disk  430   a  includes proximally angled fingers  432   a  and disk  430   b  includes distally angled fingers  432   b . Fingers  432   a  prevent distal advancement of needle  418  when enlarged diameter portion  418   b  of needle  418  is positioned between disks  430   a  and  430   b  and fingers  432   b  prevent proximal movement or retraction of needle  418  when enlarged diameter portion  418   b  is positioned between disks  430   a  and  430   b . In one embodiment, disks  430   a  and  430   b  are integrally formed and are connected together by a cylindrical wall  434 . 
         [0069]      FIGS. 18A-19  illustrate another alternate embodiment of the presently disclosed safety device shown generally as  513 . Safety device  513  includes a housing  514 , having an inner wall defining a cavity having a large diameter portion  514   a , a distally facing ramp portion  514   b , a proximally facing shoulder  514   c  and a small diameter portion  514   d . A clip  516  includes a proximal wall  520  defining an opening  522  for slidably receiving a needle  518 . Clip  516  is formed from a resilient material, e.g., spring steel, and also includes a leg  524  extending from each side of proximal wall  520 . Each leg  524  extends outwardly and distally from proximal wall  520  and includes a radially and proximally extending portion  526  ( FIG. 19 ). One radially extending portion  526  defines a cutout  530  ( FIG. 21 ) for slidably receiving needle  518  therein. 
         [0070]    In use, when needle  518  is retracted into housing  514 , enlarged diameter portion  518   b  of needle  518  will engage and deflect radially extending portions  526  of clip  516  inwardly and, subsequently, move into engagement with proximal wall  520  of clip  516 . Because enlarged diameter portion  518   b  has a larger diameter than opening  522 , further retraction of needle  518  into housing  514  pulls clip  516  over ramp portion  514   b  of housing  514  and into the small diameter portion  514   d  of housing  514  between proximally facing shoulder  514   c  and a proximal wall  540  of housing  514 . See  FIG. 18B . In this position, proximal wall  540  of housing  514  prevents retraction of needle  518  from housing  514  and shoulder  514   c  of housing  514  prevents distal advancement of needle  518  from within small diameter portion  514   d . More specifically, the small diameter portion  514   d  of housing  514  is dimensioned to prevent outward deflection of legs  524  of clip  516 . Since legs  524  are prevented from deflecting outwardly, the enlarged diameter portion  518   b  of needle  518  is prevented from being moved distally past radial portions  526  of legs  524 . It is noted that enlarged diameter portion  518   b  is too large to pass through cutout  530  in radially extending portion  526 . 
         [0071]      FIGS. 20-23  illustrate another embodiment of the presently disclosed access assembly shown generally as  700 . Access assembly  700  comprises a needle assembly  710  including a needle hub  712  supporting a distally extending needle  718 , a safety device  713  including a housing  714  and a biasing member  716 , and a catheter assembly including a catheter hub  720  and a catheter tube  720   a  extending distally from the catheter hub  720 . In a ready-to-use position, the housing  714  of the safety device  713  is supported between the needle hub  712  and the catheter hub  720  and the needle  718  extends through the safety device housing  714  and the catheter hub  720  such that a tip  718   a  of needle  718  projects from a distal end of the catheter tube  720   a.    
         [0072]    The safety clip housing  714  defines a distal opening  724  and a proximal opening  726  and includes a distal wall  728 , a proximal wall  730  and sidewalls  732 . The biasing member  716  is supported within housing  714  between a sidewall  732  and needle  718 . See  FIG. 23 . In the ready-to-use position of access assembly  700  shown in  FIGS. 20-21 , needle  718  extends through distal and proximal openings  724  and  726  of housing  714  and includes a tip  718   a  which extends from catheter tube  720   a . In addition, the biasing member  716  is compressed between sidewall  732  and needle  718 . Housing  714  also includes a hook portion  734  ( FIG. 22 ) which is engaged with a luer connector  738  of catheter hub  720 . 
         [0073]    Referring to  FIGS. 22-23 , when needle  718  is retracted to withdraw tip  718   a  into housing  714  of safety device  713 , biasing member  716  expands towards a non-compressed position to tilt the housing  714  with respect to needle  718 . When this occurs, the distal opening  724  of housing  718  becomes misaligned with the longitudinal axis of needle  718  and the needle tip  718   a  is covered by distal wall  728  of housing  714 . During tilting of housing  714 , hook portion  734  is disengaged from catheter hub  720  to release housing  714  from catheter hub  720 . 
         [0074]    Needle  718  includes a crimp  718   b  and a bushing  750  positioned proximally of crimp  718   b . As discussed above with respect to previous embodiments, crimp  718   b  and bushing  750  prevent withdrawal of needle  718  through proximal opening  726  of housing  714  to safely retain needle tip  718   a  within housing  714  of safety device  713 . In this embodiment, as well as in previous embodiments, the bushing  750  is not necessary and the crimp  718   b  can be sized to prevent retraction of the needle through a proximal opening of the safety device housing  714 . 
         [0075]    Persons skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. It is envisioned that the elements and features illustrated or described in connection with one exemplary embodiment may be combined with the elements and features of another without departing from the scope of the present disclosure. As well, one skilled in the art will appreciate further features and advantages of the disclosure based on the above-described embodiments. Accordingly, the disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.