Abstract:
The present invention is a method for assembling a safety shield assembly and more particularly a method for assembling a safety shield assembly with a fluid handling device. Preferably, the safety shield assembly may be assembled with a needle assembly, an intravenous infusion set a syringe, a catheter or other fluid handling devices or assemblies that contain piercing elements.

Description:
RELATED APPLICATION 
   This application is a continuation of U.S. patent application Ser. No. 10/156,611, now U.S. Pat. No. 7,223,258, file May. 24, 2002, which is a continuation-in-part of prior U.S. Pat. No. 6,440,104 filed Aug. 23, 1999, which claims the benefit of U.S. Provisional Application No. 60/098,286, filed on Aug. 28, 1998. 

   FIELD OF THE INVENTION 
   The present invention relates to a shield for a needle and more particularly to a safety shield assembly that may be used in conjunction with a syringe assembly, a hypodermic needle, a needle assembly, a needle assembly with a needle holder, a blood collection needle, a blood collection set, an intravenous infusion set or other fluid handing devices or assemblies that contain piercing elements. 
   BACKGROUND OF THE INVENTION 
   Disposable medical devices having piercing elements for administering a medication or withdrawing a fluid, such as hypodermic needles, blood collecting needles, fluid handling needles and assemblies thereof, require safe and convenient handling. The piercing elements include, for example, pointed needle cannula or blunt ended cannula. 
   Safe and convenient handling of disposable medical devices is recognized by those in the medical arts so as to minimize exposure to blood borne pathogens. Safe and convenient handling of disposable medical devices results in the disposal of the medical devices intact. 
   As a result of this recognition, numerous devices have been developed for shielding needles after use. Many of these devices are somewhat complex and costly. In addition, many of these devices are cumbersome to use in performing procedures. Furthermore, some of the devices are so specific that they preclude use of the device in certain procedures or with certain devices and/or assemblies. For example, some devices employ very short thin needle cannulas. A shield designed to lock near the distal end of one needle cannula might not engage a much shorter needle cannula. Additionally, a shield designed to lock with a wider gauge needle cannula might be more likely to generate a spray upon engaging a much narrower needle cannula. Furthermore, it may be desirable to reduce the force required to effect shielding without reducing the audible and tactile indications of complete shielding. 
   Therefore, there exists a need for a safety shield assembly: (i) that is manufactured easily; (ii) that is applicable to many devices; (iii) that is simple to use with one hand; (iv) that can be disposed of safely; (v) that does not interfere with normal practices of needle use; (vi) that has tactile features whereby the user may be deterred from contacting the needle, the user may easily orient the needle with the patient and easily actuate and engage the shield assembly; (vii) that has visual features whereby the user may be deterred from contacting the needle, the user may easily orient the needle with the patient and easily actuate and engage the shield assembly; (viii) that is not bulky; (ix) that includes means for minimizing exposure to the user of residual fluid leaking from the needle; and (x) provides minimal exposure to the user because the needle shield is immediately initiated by the user after the needle is withdrawn from the patient&#39;s vein. 
   SUMMARY OF THE INVENTION 
   The present invention is a safety shield assembly that comprises: a shield; means for connecting the shield to a fluid handling device that contains a piercing element, such as needle; means for pivoting the shield away from the needle; means for securely covering and/or containing the needle within the shield and means for securely locking the shield in a final non-retractable closed position over the needle. 
   Preferably, the shield comprises a rearward end, a forward end, a slot or longitudinal opening for housing the used needle in the forward end, means for securing the needle in the slot, means for guiding the needle into the slot, means for connecting the shield and the fluid handling device, means for guiding the user&#39;s fingers to move the shield into various positions, and means for retaining the shield securely over the used needle. 
   Desirably, the means for connecting the shield to the fluid handling device is a collar. Preferably, the shield is connected movably to a collar which is connected to a fluid handling device. 
   Preferably, the shield is connected to the collar by a hanger bar that engages with a hook arm on the collar so that the shield may be pivoted with respect to the collar into several positions. It is within the purview of the present invention to include any structure for connecting the shield to the collar so that the shield may be pivoted with respect to the collar. These structures include known mechanical hinges and various linkages, living hinges, or combinations of hinges and linkages. 
   Most preferably, the shield is connected to the collar by an interference fit between the hanger bar and the hook bar. Therefore, the shield always is oriented in a stable position and will not move forward or backwards unless movement of the shield relative to the hanger bar and the hook bar is initiated by the user. 
   Alternatively, the shield and collar may be a unitary one-piece structure. The one-piece structure may be obtained by many methods, including molding the shield and the collar as a one-piece unit, thereby eliminating the separate shield and collar during the manufacturing assembly process. 
   The assembly of the present invention may further comprise tactile and visual means for deterring the user from contacting the needle, providing easy orientation of the needle with the patient and providing the user with a guide for actuation and engagement with the shield. 
   The assembly of the present invention may further comprise means for minimizing exposure by the user to residual fluid leaking from a used needle. For example, a polymer material, such as a gel, may be located in the shield. 
   Most desirably, the assembly of the present invention is such that the cooperating parts of the assembly provide the means for the shield to move into a forward position over the needle. Thus, by simple movement of the shield into a forward position over the used needle, the assembly is ready for subsequent disposal. Therefore, the safety shield assembly of the present invention provides minimal exposure of the user to a needle because the shielding is initiated by the user immediately after the needle is withdrawn from the patient&#39;s vein. 
   Desirably, the assembly of the present invention may be used with a syringe assembly, a hypodermic needle, a needle assembly, a needle assembly with a needle holder, a blood collection set, an intravenous infusion set or other fluid handling devices. Preferably, the assembly of the present invention is used with a needle assembly comprising a needle and a hub. Preferably the needle is a conventional double ended needle. 
   Most preferably, the present invention is used with a needle assembly comprising a hub and a needle connected to the hub whereby the needle comprises a non-patient end and an intravenous end. The collar of the present invention may comprise a hook arm and the shield may be connected movably to the hook arm. Thus the shield may be pivoted with respect to the collar and moved easily into several positions. 
   Preferably, the collar is fitted non-rotatably with the hub of the needle assembly. Additionally, the collar includes cooperating means that mate with reciprocal means on the shield to help retain the shield in a final closed position, to propel the shield toward the final closed portion and to provide a clear audible and tactile indication of complete shielding. 
   The shield preferably includes at least one cannula finger lock for locked engagement with the cannula when the shield is in the final closed position around the needle cannula. The cannula finger lock preferably projects obliquely from one sidewall of the shield angularly toward the opposed sidewall and the top wall of the shield. The cannula finger lock is dimensioned, disposed and aligned to contact the needle cannula when the shield approaches the final closed position. Contact between the cannula and the cannula finger lock will cause the cannula finger lock to resiliently deflect toward the sidewall from which the cannula finger lock extends. Sufficient rotation of the shield will cause the needle cannula to pass the cannula finger lock. As a result, the cannula finger lock will resiliently return to or toward its undeflected condition for securely trapping the needle cannula in the shield. 
   The shield also preferably includes at least one cannula shelf lock. The cannula shelf lock projects substantially rigidly from a sidewall of the shield. The cannula shelf lock may be a generally triangular panel with a lower edge that is inclined closer to the top wall of the shield at further distances from the sidewall on which the shelf lock is disposed. The shelf lock may further include a top edge that extends substantially parallel to the axis of rotation of the shield and/or substantially parallel to the top wall of the shield. The top edge of the shelf lock may include a recess or groove approximately symmetrically between the sidewalls of the shield for trapping the needle cannula. The cannula shelf lock functions differently from the cannula finger lock. In particular, the cannula finger lock is dimensioned and aligned to deflect in response to engagement with the needle cannula. The cannula shelf lock, on the other hand, is dimensioned and aligned to generate deflection of the needle cannula. Thus, the cannula shelf lock will cause the needle cannula to deflect transversely a sufficient distance for the needle cannula to clear the shelf lock. After sufficient rotation, the needle cannula will clear the shelf lock and resiliently return toward an undeflected condition. Thus, the cannula shelf lock will substantially prevent a re-exposure of the used needle cannula. 
   Preferably, the collar is fitted with the hub of the needle assembly so that the collar cannot rotate around the hub. Additionally, the collar includes cooperating means that mate with reciprocal means on the shield to propel the shield toward a final closed position. 
   Alternatively, the collar and hub may be a unitary one-piece structure. The one piece structure may be accomplished by many methods including molding the collar and the hub as a one-piece unit thereby eliminating the need to separately assemble the collar to the hub during the manufacturing process. 
   Most preferably, the collar is fitted with the hub of the needle assembly so that the bevel surface or bevel up surface of the intravenous or distal end of the needle faces the same side of the collar when the shield is in the open position. Alignment of the collar, hub, shield and needle with the bevel surface up makes it easier to insert the needle into the patient without manipulating the assembly. The orientation of the intravenous end of the needle with the bevel up assures the user that the needle is properly oriented properly for use and does not require any manipulation before use. Most notably, the orientation of the shield provides a visual indication to the user of the orientation of the bevel surface of the needle. 
   Preferably, the shield is capable of pivoting from an open position where the intravenous end of the needle is exposed and bevel up, to an intermediate position where the needle is partially covered, to a final closed nonretractable position where the needle is covered completely and the shield is locked and no longer able to be moved out of the closed position. 
   Alternatively, it is within the purview of the present invention that the shield, collar and hub is a unitary one-piece structure. The one-piece structure may be accomplished by many methods including molding the shield, collar and hub as a one-piece unit thereby eliminating the need to separately assemble the shield, collar and hub during the manufacturing process. 
   It is an advantage of the present invention that the shield covering the used intravenous end of the needle provides easy containment of the used needle. A further advantage of the shield is that it will only move upon initiation by the user. 
   The assembly of the present invention when used with a fluid handling device is also easily disposable when removed from a conventional needle holder, or other such device. 
   Another important feature of the present invention includes means for locking the shield in a closed permanent position covering the needle. The closed permanent position will generally withstand the normal forces encountered during proper disposal of the safety shield assembly when it is removed from a conventional needle holder. 
   A notable attribute of the present invention is that it is easily adaptable with many devices. For example, the invention is usable with syringe assemblies, hypodermic needles, needle holders, blood collection needles, blood collection sets, intravenous infusion sets such as catheters or other fluid handling devices or assemblies that contain piercing elements. 
   Another notable attribute of the present invention is that the tactile and visual features deter the user from touching the needle, allow the user to easily orient the needle with the patient and guide the user to actuate and engage the shield of the assembly. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of the safety shield assembly of the present invention as connected to a needle assembly and related packaging features. 
       FIG. 2  is a perspective view of the unassembled pieces of  FIG. 1 . 
       FIG. 3  is a bottom view of the shield as shown in  FIG. 2 . 
       FIG. 4  is a cross sectional view of the collar as shown in of  FIG. 2  taken along lines  4 - 4  thereof. 
       FIG. 5  is a cross sectional view of the needle hub as shown in  FIG. 2  taken along lines  5 - 5  thereof. 
       FIG. 6  is a cross sectional view of the shield of  FIG. 2  taken along lines  6 - 6  thereof. 
       FIGS. 7-12  illustrate the use of the safety shield assembly with the needle assembly of  FIG. 1  with a conventional needle holder. 
       FIG. 13  is a cross sectional view of the assemblies in use with a conventional needle holder as shown in  FIG. 12  taken along lines  13 - 13  thereof. 
       FIG. 14A  is a cross-sectional view of the assemblies of  FIG. 13  taken along lines  14 A- 14 A thereof. 
       FIG. 14B  is a cross-sectional view of the assemblies of  FIG. 13  taken along lines  14 B- 14 B thereof. 
       FIG. 15  is a bottom view of the assemblies as shown in  FIG. 11 . 
       FIG. 16  illustrates an additional embodiment of the present invention, whereby a gel material is located in the shield as shown in a bottom view of the assemblies of  FIG. 11 . 
       FIG. 17  is a perspective view of an additional embodiment of the present invention in use with a blood collection set. 
       FIG. 18  is a perspective view of an additional embodiment of the present invention in use with a syringe. 
       FIG. 19  is a perspective view of an additional embodiment of the present invention in use with a catheter. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   While this invention is satisfied by embodiments in many different forms, there is shown in the drawings and will herein be described in detail, the preferred embodiments of the invention, with the understanding that the present disclosure is to be considered as exemplary of the principles of the invention and is not intended to limit the invention to the embodiments illustrated. Various other modifications will be apparent to and readily made by those skilled in the art without departing from the scope and spirit of the invention. The scope of the invention will be measured by the appended claims and their equivalents. 
   Referring to the drawings in which like reference characters refer to like parts throughout the several views thereof,  FIGS. 1 and 2  illustrate a needle assembly with the safety shield assembly of the present invention and the related packaging features. The needle assembly includes a needle  40 , a hub  60 , packaging features to cover the needle and a label. The safety shield assembly includes a collar  90  and a shield  140 . 
   As shown in  FIGS. 2 and 5 , needle  40  includes a non-patient end  42 , an intravenous end  44  and a passageway  46  extending between the non-patient end and the intravenous end. An elastomeric sleeve  48  covers the non-patient end. A first rigid sleeve  50  covers the intravenous end and a second rigid sleeve  52  covers the non-patient end and the elastomeric sleeve. As shown in  FIG. 1 , a label  196  may also be applied to the finally assembled parts. 
   As shown in  FIGS. 2 and 5 , hub  60  includes a threaded end  64 , a ribbed end  66  and passageway  62  extending between the threaded end and the ribbed end. Threaded end  64  and ribbed end  66  are separated by flange  68 . Non-patient end  42  of needle  40  extends from threaded end  64  and intravenous end  44  of needle  40  extends from ribbed end  66 . Preferably, threaded end  64  comprises male threads  80  for mounting the hub on a conventional needle holder and ribbed end  66  comprises male ribs  82  for connecting the hub and collar  90 . 
   As shown in  FIGS. 2 and 4 , collar  90  includes a forward skirt  92  and a rearward skirt  94 . Forward skirt  92  is cylindrical and comprises an inner circumferential surface  96  and an outer circumferential surface  98 . Forward shirt  92  mates with rearward skirt  94  at a shoulder  100 . Rearward skirt  94  is cylindrical and comprises an inner circumferential surface  102  and an outer circumferential surface  104  and extends from shoulder  100  opposite of forward skirt  92 . The inner diameter of forward skirt  92  is larger than the inner diameter of rearward skirt  94 . Alternatively, the inner diameters for collar  90  can be equal. A hook  114  extends from outer circumferential surface  98  of forward skirt  92 . Additionally, detents or protrusions  118  project outwardly from outer circumferential surface  98  of forward skirt  92  at a side opposite hook  114 . Protrusions  118  may define a substantially chevron-shape with well defined edges  119  facing toward rearward skirt  94 . 
   As shown in  FIGS. 2 and 6 , shield  140  comprises a rearward end  144  and a forward end  146 . 
   Forward end  146  of shield  140  includes a slot or longitudinal opening  160  formed by sidewalls  162  that extend downwardly from top wall  163  and run substantially opposite of one another in parallel along the length of slot  160  towards forward end wall  164 . Slot  160  is slightly wider than needle  40 . Sidewalls  162  include bottom edges  165  that extend substantially parallel to one another and parallel to top wall  163 . 
   A cannula finger lock  167  is located at one of sidewalls  162  and is configured to secure the used needle. Cannula finger lock  167  extends from a location on a first of the sidewalls  162  adjacent the bottom edge  165  thereof and projects angularly toward the opposed sidewall  162  and toward the top wall  163 . The projection of the cannula finger lock  167  from the respective sidewall  162  preferably exceeds half the distance between the respective sidewalls. Cannula first lock  167  is deflectable by the needle when the needle enters slot  160 . Once the needle passes the end of cannula finger lock  167 , the cannula finger lock moves back to its original position so that the needle is permanently trapped in slot  160  by cannula finger lock  167 . 
   Rearward end  144  of shield  140  defines a collar engaging area  166  that is a continuation of slot  160 . Collar engaging area  166  includes a rearward end  168 , a forward end  170 , a top finger guide area  172 , sidewalls  174  that extend downwardly from top finger guide area  172 , an underside area  176  dimensioned for surrounding collar  90 , and extending arms  180  to support hold hanger bar  182 . Sidewalls  174  are spaced apart by a major width adjacent rearward end  168 . The major width is selected to enable sidewalls  174  to slide across diametrically opposite side surfaces of forward skirt  92  of collar  90 . Sidewalls  174  converge, however, toward forward end  170  to define a minor distance therebetween substantially equal to the distance between sidewalls  162  at forward end  146  of shield  140 . Sidewalls  174  include bottom edges  177  that face away from top finger guide area  172 . As shown most clearly in  FIG. 6 , bottom edges  177  curve toward top finger guide area  172  at locations between rearward end  168  and forward end  170  of collar engaging area  166 . 
   Shield  140  further includes a cannula shelf lock  220 . Cannula shelf lock  220  is a substantially planar and substantially rigid panel that projects orthogonally from one side wall  174  at a location at or near the interface of forward sidewalls  162  and rearward sidewalls  174 . Cannula shelf lock  220  includes a bottom edge extending substantially from bottom edge  177  of sidewall  174  angularly toward top wall  163  and/or top finger guide area  172 . Cannula shelf lock  220  further includes a top edge  224  aligned substantially parallel to the axis about which shield  140  rotates. Top edge  224  includes a cylindrically generated concavity  226  generated about an axis extending parallel to top wall  163  and dimensioned to accommodate needle  44 . Slanted bottom edge  222  and top edge  224  meet at a corner  228  that is spaced from the opposed sidewall of shield  140  by a distance that exceeds the outside diameter of needle  44 . 
   The extreme rear ends of sidewalls  174  on collar engaging area  166  include rounded ears  194  that project toward one another from opposed inner surfaces  175  of sidewalls  174 . Rounded ears  194  are disposed to engage detents  118  on collar  90 . More particularly, each rounded ear  194  includes a distal surface  195 , a proximal surface  197  and a curved surface  198  extending between distal and proximal surfaces  195  and  197 . Distal surface  194  is aligned to sidewall  174  at a rake angle of approximately 60° and proximal surface  197  is aligned to sidewall  174  at an angle of approximately 45°. Curved surface  198  extends smoothly and convexly between distal and proximal surfaces  195  and  197 . Proximal surfaces  197  of rounded ears  194  will engage detents  118  to deflect sidewalls  174  slightly away from one another as shield  140  approaches the second position. This deflection of sidewalls  174  will occur substantially simultaneously with the deflection of cannula finger lock  167  and with the deflection of needle  44  in response to engagement with cannula shelf lock  220 . The apex of curved surface  198  on each rounded ear  194  passes the respective detent  118  on collar  90  slightly before cannula finger lock  167  and cannula shelf lock  220  pass the needle cannula. As a result, sidewalls  174  begin to return resiliently toward an undeflected condition. This resilient return of sidewalls  174  cooperates with raked distal surfaces  195  on rounded ears  194  to propel shield  140  into the second position where cannula finger lock  167  and cannula shelf lock  220  pass needle  44 . This acceleration of shield  140  caused by the resilient return of sidewalls  174  and raked distal surface  195  of ears  194  also causes sidewalls  174  to snap against detents  118 . This snapping action provides a clear audible and tactile indication of complete shielding and occurs substantially when the used needle is trapped by cannula finger lock  167  and cannula shelf lock  220 . The angles of distal and proximal surfaces  195  and  197  of rounded ears  194  affects the performance of shield  140 . In particular, a smaller acute angle alignment of proximal face  197  reduces the force required to move shield  140  passed rounded ears  194 . A larger acute angle proximal surface  197  of rounded ears  194  requires a greater force to move shield  140  toward the second position. Similarly, the angle between distal surface  195  and sidewall  174  affects the acceleration characteristics as shield  140  is propelled toward the second position in response to the resilient return of sidewalls  174 . 
   Top finger guide area  172  comprises a first ramp  184  that extends slightly on an upwardly slope from the rearward end of the collar engaging area to a shoulder  186 . From shoulder  186  extends a second ramp  188  which slopes downwardly towards top section  163 . Most preferably, first ramp  184  comprises touch bumps  190 . The touch bumps provide a tactile and visual guide to alert the user that the user&#39;s finger has contacted the shield and that the shield is in a defined or controlled position. The touch bumps may be any configuration so long as they extend and are distinct from the top finger guide area. The touch bumps may also be of a distinguishing color as compared to the top finger guide area or the shield. 
   Second ramp  188  has interior surface  192  for urging the needle toward the center of slot  160  as the shield is being rotated into the closed position. The exterior surfaces are slightly inclined and extending radially from the second ramp. The interior surfaces are especially helpful if the longitudinal axis of the needle is misaligned with respect to the longitudinal axis of the hub. 
   Extending arms  180  are located at rearward end  168  and at the beginning of top finger area  172  and hold hanger bar  182 . 
   The safety shield assembly and the needle assembly are assembled together whereby needle  40  is connected to hub  60  and sealed with adhesive at the ends of the hub. Hub  60  is then joined with collar  90  by ultra-sonic welding techniques or any other bonding techniques, or mechanical fit, whereby rearward annular skirt  94  of collar  90  mates with ribbed end  66  of the hub. Male ribs  82  of the hub are contained or forced fitted within inner sidewall  102  of rearward annular skirt  94  of collar  90 . The collar is aligned with the intravenous end of the needle whereby the hook arm is aligned with the bevel up of the needle. Then rigid sleeve  50  is force fitted into inner side wall  96  of forward skirt  92  of collar  90  to cover the needle. Thereafter, shield  140  is connected to collar  90  whereby hanger bar  182  is force fitted into hook member  114  whereby slot  160  faces rigid sleeve  50 . Most preferably, the shield is connected to the collar by a force fit or interface fit between the hanger bar and the hook bar. Therefore, the shield is always oriented in a stable position and will not move unless movement of the shield is positively initiated by the user. To assemble the last piece, shield  140  is moved towards rigid sleeve  50  and second rigid sleeve  52  is force fitted onto outer sidewall  104  of rearward skirt  94  of collar  90 . 
   In addition, a label  196  may be applied to the finally assembled parts. The label may be used to prevent tamper resistance of the parts, so that they are not reused. 
   In use, as shown in  FIGS. 7-15 , the non-patient needle shield is removed and then a needle holder is screwed onto the hub of the needle. As specifically shown in  FIGS. 8 and 12  the shield is then rotated back by the user towards the needle holder. Then as shown in  FIG. 9 , the intravenous needle shield is removed from covering the intravenous needle. Then as shown in  FIG. 10 , a venipuncture is conducted whereby the intravenous end of the needle is inserted into a vein of a patient and an evacuated tube having a closure is inserted into the needle holder. Then as shown in  FIGS. 11 and 13 , when the venipuncture is complete the user easily rotates the shield from the open position towards the intravenous needle to an intermediate position and then the user pushes on the shield at the top finger guide area to move the shield into a final, non-retractable locked position whereby the needle is trapped in the longitudinal opening. More particularly, needle  44  contacts cannula finger lock  167  and cannula shelf lock  220 . The engagement of needle  44  with cannula finger lock  167  causes cannula finger lock  167  to deflect toward top wall and toward the sidewall  162  from which cannula finger lock  167  projects. Simultaneously, sloped bottom edge  222  of cannula shelf lock  220  will cause needle  44  to deflect. Sufficient rotation of shield  140  will cause needle  44  to pass both cannula finger lock  167  and cannula shelf lock  220 . As a result, cannula finger lock  167  will return resiliently to an undeflected condition and needle  44  will return resiliently to an undeflected condition. Thus, needle  44  will be trapped above cannula finger lock  167  and above cannula shelf lock  220 . Additionally, needle  44  will be retained securely in concave region  226  of cannula shelf lock  220 . The combination of cannula finger lock  167  and cannula shelf lock  220  can provide more secure protection than a single cannula finger lock or a plurality of finger locks. More particularly, a cannula finger lock provides a secure trapping of needle  44 , albeit with relatively low resistance to a forced attempt to intentionally re-expose needle  44 . On the other hand, shelf lock  220  provides somewhat less effective trapping than cannula finger lock  167  in that a transverse shifting for the shield could bypass a cannula shelf lock that was used alone. However, a cannula shelf lock provides much more secure resistance to a forcible attempt to rotate shield  140  back to its initial position. Thus, the cannula finger lock  167  and cannula shelf lock  220  cooperate to provide significantly enhanced trapping and resistance to re-exposure of cannula  44 . 
   Needle  44  is contained within shield  140  as the shield is pivoted into the closed position. More particularly, proximal surfaces  197  of rounded ears  194  move over detents  118  and cause sidewalls  174  to deflect away from one another. The angularly aligned proximal faces  197  of rounded ears  194  ensures easy movement of shield  140 . Additionally, the resiliency of sidewalls  174  and the angular alignment of distal surface  195  of ears  194  causes shield  140  to be accelerated into the full shielding closed position. Thus needle  44  snaps past cannula finger lock  167  and cannula shelf lock  220  and is trapped as shown in  FIGS. 14A ,  14 B and  15  to ensure complete locking of shield  140  in the closed position. This accelerated movement of shield  140  helps to generate a clear audible and tactile indication of complete shielding. 
   Alternatively as shown in  FIG. 16 , a gel material  190  is located in shield  140  so that when the needle snaps past cannula finger lock  167  and cannula shelf lock  220  it will come to rest in gel material  190 . The gel material will contain any residual fluid that may be on the needle. Simultaneously, rounded ears or projections  198  move over detents  118 . This causes sidewalls  174  to deflect away from one another and then to snap back into engagement with collar  90  to provide a clear audible and tactile indication of complete shielding. 
     FIGS. 17 ,  18 , and  19  are further embodiments of the invention that include may components which are substantially identical to the components.  FIGS. 1-3 . Accordingly, similar components performing similar functions will be numbered identically to those components of  FIGS. 1-3 , except that a suffix “a” will be used to identify those similar components in  FIG. 17 , a suffix “b” will be used to identify those similar components in  FIG. 18  and a suffix “c” will be used to identify those similar components in  FIG. 19 . 
   Alternatively, the safety shield assembly of the present invention may be used in conjunction with a conventional intravenous (IV) fusion set, as illustrated in  FIG. 17 . 
   For purposes of illustration, shield  140   a  and collar  90   a  are connected to a conventional IV infusion set,  200 , or butterfly structure comprising a needle body with a needle hub  204  extending from the forward end of the needle body and a needle  206  embedded in hub  204 . Extending from the rearward end of the needle body is flexible tubing  208  which is conventional and utilized to allow the user to manipulate the structure and to connect it subsequently to supplies of infusion liquids or for the return of collected blood if the arrangement is being used to collect blood. 
   Infusion set  200  further comprises flexible wings  210  attached to and projecting outwardly from needle hub  204 . 
   Alternatively, the safety shield assembly of the present invention may be used in conjunction with a syringe, as illustrated in  FIG. 18 . 
   For purposes of illustration, shield  140   b  and collar  90   b  are connected to a conventional hypodermic syringe  300  comprising a syringe barrel  302  having a distal end  304  a proximal end  306  and a plunger  312 . 
   Alternatively, the present invention may be used in conjunction with a catheter as illustrated in  FIG. 19 . 
   The shield and collar of the safety shield assembly of the present invention are comprised of moldable parts which can be mass produced from a variety of materials including, for example, polyethylene, polyvinyl chloride, polystyrene or polyethylene and the like. Materials will be selected which will provide the proper covering and support for the structure of the invention in its use, but which will provide also a degree of resiliency for the purpose of providing the cooperative movement relative to the shield and the collar of the assembly.