Patent Abstract:
A device that is used in conjunction with a needle-based medication injection device (e.g. a prefilled syringe) that prevents needle stick injuries. The used needle is shielded by a needle guard that surrounds and extends beyond the needle tip. In a preferred embodiment, before the needle is inserted into the patient, the needle guard projects forward to substantially hide visibility of the needle for safety and to reduce patient anxiety.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The subject application is a continuation-in-part of application Ser. No. 12/859698 filed Aug. 19, 2010, which claims the benefit of provisional application Ser. No. 61/235,278 filed Aug. 19, 2009, which applications are incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The following describes a device that is used in conjunction with a needle-based medication injection device (e.g. a prefilled syringe) that prevents needle stick injuries. The used needle is shielded by a cylindrical needle guard that surrounds and extends beyond the needle tip. In a preferred embodiment, before the needle is inserted into the patient, the needle guard projects forward to protect and substantially hide visibility of the needle to reduce patient anxiety. 
       BACKGROUND 
       [0003]    The glass syringe and rubber stopper have for years provided an ideal drug storage closure having unique properties of impermeability to oxygen, low extractables, biocompatability, durability, etc. However, they are both formed by processes that do not lend themselves to tight geometrical tolerances. For instance, the syringe flange is formed when a glass tube is heated to a soft state and the edges pressed over to form an edge. Typical tolerances for the inside length of a syringe or the length of a stopper are both +/−0.5 mm. The finger flange thickness has a similar tolerance. Furthermore, tight tolerances were not originally needed by these devices because they were not used mechanically with other devices. Existing passive anti-needle stick safety devices for prefilled syringes must mount to the syringe but not interfere excessively with the force required to move the plunger rod during injection nor prevent the full travel of the plunger rod, which terminates when the stopper reaches the distal end of the inside of the syringe. The safety mechanism necessarily must be triggered toward the end of administration of the drug (near the end of the plunger rod travel). However, since virtually all safety devices locate the syringe against the safety device at a point under the syringe finger flange, a stack up of worst-case tolerances can put the required plunger rod travel variance at +/−1.5 mm, when considering the tolerances of the inside length of the syringe, syringe flange thickness, and stopper length (syringe manufacturers reference the syringe inside length from the proximal end of the syringe, not the distal underside of the finger flange). Accommodating the 3 mm plunger rod position variance is very difficult for safety devices and it is desirable to reduce and or eliminate any dependence of the safety device on the syringe and stopper tolerances. 
       SUMMARY 
       [0004]    The present safety device described herein is directed to a needle guard for a syringe having the safety device triggering mechanism independent of the syringe and stopper tolerances. The present device is triggered when the needle guard body is displaced proximally relative to the device as the needle is inserted into the patient. The triggering point is broadly placed between point C and an angled step-down feature proximal to point C ( FIG. 4A ). As long as the needle guard body is displaced proximally a certain distance, the device will lockout, in a manner which is almost completely independent of the syringe or stopper geometry. 
         [0005]    The present safety device also makes locking the needle shield completely contemporaneous with needle removal from the patient, reducing the possibility of needle stick injuries when, for instance, a patient suddenly jerks or flinches causing the needle to come out of the patient unexpectedly. Most commercially available needle safety devices require the plunger rod to be fully depressed in order to activate the safety mechanism. 
         [0006]    Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0007]    The details of the invention, including fabrication, structure and operation, may be gleaned in part by study of the accompanying figures, in which like reference numerals refer to like parts. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, all illustrations are intended to convey concepts, where relative sizes, shapes and other detailed attributes may be illustrated schematically rather than literally or precisely. 
           [0008]      FIG. 1  illustrates the fully assembled device. 
           [0009]      FIG. 2  illustrates the fully assembled device quarter section view. 
           [0010]      FIG. 3  illustrates the exploded view of the various components of the device. 
           [0011]      FIG. 4A  illustrates the needle guard body grooves showing a position (A, B, C and D) of the main body protrusions during the steps of operating the device. 
           [0012]      FIG. 4B  illustrates the main body protrusion at position A of the needle guard body groove prior to removal of the rigid needle shield (RNS) and RNS removal tool. A section of the main body is removed for visualization of the needle guard body groove. 
           [0013]      FIG. 4C  illustrates the main body protrusion at position B of the needle guard body groove after the RNS and RNS removal tool have been removed. A section of the main body is removed for visualization of the needle guard body groove. 
           [0014]      FIG. 4D  illustrates the main body protrusion in transit between position C and D of the needle guard body groove. This would occur after the injection has taken place and the device is being withdrawn from the injection site. A section of the main body is removed for visualization of the needle guard body groove. 
           [0015]      FIG. 4E  illustrated the main body protrusion in position D of the needle guard body groove, in the locked out state. A section of the main body is removed for visualization of the needle guard body groove. 
           [0016]      FIG. 4F  illustrates a cross sectional view of the main body protrusions in position D of the needle guard body groove where the main body protrusion is substantially captured in a deepening of the groove to lock the device. 
           [0017]      FIG. 5  illustrates the RNS removal tool. A section of the main body and needle guard body is removed for visualization of the RNS removal tool. 
           [0018]      FIG. 6  illustrates the device ready for medication dispensing. 
           [0019]      FIG. 7  illustrates first step of medication dispensing. 
           [0020]      FIG. 8  illustrates medication dispensing steps and a cross section of the device after an injection of medication. 
           [0021]      FIG. 9  illustrates removal of the device and needle from the injection site. 
           [0022]      FIG. 10  illustrates the final safety configuration of the device. 
           [0023]      FIG. 11  illustrates the main body window position prior to the removal of the RNS and RNS removal tool. 
           [0024]      FIG. 12  illustrates the main body window and needle guard body window position after the RNS and RNS removal tool have been removed and the needle guard body has moved forward. 
           [0025]      FIG. 13  illustrates an alternative embodiment of the RNS removal tool. 
           [0026]      FIG. 14  illustrates the RNS removal tool radial cam mechanism, which acts to engage or grasp the RNS upon initial rotation. 
           [0027]      FIG. 15  illustrates the RNS removal tool axial cam mechanism, which acts to pull the RNS from the syringe in an axial direction. 
           [0028]      FIG. 16  illustrates the nominal orientation of the RNS removal tool retention barb, allowing syringe assembly. 
           [0029]      FIG. 17  illustrates the removal tool retention barb engaging proximal end of the RNS. 
           [0030]      FIG. 18A  illustrates an exploded view of another embodiment of the RNS removal tool having a RNS removal tool cap and a RNS removal tool elastomeric insert. 
           [0031]      FIG. 18B  is a detailed quarter section view showing the alternative embodiment of the RNS removal tool improvement. 
           [0032]      FIG. 19  illustrates another embodiment of the main body window position prior to the removal of the RNS and RNS removal tool. 
           [0033]      FIG. 20  Illustrates an alternate embodiment before the RNS has been removed, where the RNS removal tool is concentric to and positioned around the syringe barrel so that during RNS removal, as the RNS removal tool is rotated, the RNS removal tool capture lip presses against the syringe and not the RNS. 
           [0034]      FIG. 21  illustrates the alternate embodiment from  FIG. 20  after the RNS removal tool has been rotated and the RNS removal tool capture lips have been pressed against the syringe. 
           [0035]      FIG. 22  illustrates the alternate embodiment from  FIGS. 20 and 21  after the RNS removal tool has begun moving axially in a distal direction away from the syringe and the RNS removal tool capture lip has captured the RNS. 
           [0036]      FIG. 23  Illustrates the RNS removal tool of the alternate embodiment described in  FIG. 20 . 
           [0037]      FIG. 24  Illustrates the interaction between the RNS removal tool retention barb and its interface with the main body retention window of the alternate embodiment described in  FIG. 20 . 
           [0038]      FIG. 25  illustrates the alternate embodiment of the RNS shown in  FIG. 20  and syringe subassembly. 
           [0039]      FIG. 26  illustrates a cross sectional view of the alternate embodiment of the RNS shown in  FIG. 20  and syringe subassembly. 
       
    
    
     DETAILED DESCRIPTION 
       [0040]    The present safety device described herein is directed to a needle guard for a syringe having the safety device triggering mechanism independent of the syringe and stopper tolerances. The fully assembled safety device  10  is shown in  FIG. 1 . The assembly of the device  10  comprises a main body  60  with a plunger  22  emanating proximally from the proximal end  68  and a rigid needle shield (RNS)  40  and RNS removal tool  50  emanating distally from the main body  60 . Inside the device  10 , as shown in  FIG. 2 , is a prefilled syringe  20  with an attached needle  24  with the RNS  40  covering over the needle  24  to protect the needle and maintain a sterile barrier for the medication injection pathways. At the distal end of the assembly is the RNS removal tool  50 , which is a removable covering over the RNS  40  that facilitates its removal just before injecting medication into the patient. The plunger  22  is attached to a syringe stopper  26 . At the distal end of the assembly inside the main body  60  is the needle guard body  80 , which is a tube that is concentric and interior to the main body  60  (see  FIGS. 2 ,  3 ,  5 , and  6 ). 
         [0041]    As shown in  FIGS. 2 and 3 , the needle guard body  80  is axially slide-able with respect to the rest of the main body  60  and is biased in a distal direction by a compression spring  61  positioned between a syringe flange  34  and the needle guard body  80 , and acting on a proximal end  82  of the needle guard body  80 . Initially, the needle guard body  80  is held in a proximal position by the RNS removal tool  50 . The RNS removal tool  50  is held in this position against the force of the spring  61  by retention barbs  54  that project outwardly at the proximal end  55  of the RNS removal tool  50  and that mate with corresponding retention windows  62  in the wall  63  of the main body  60  of the device  10  (see  FIGS. 3 ,  5 ,  11 ,  13 - 16 ). 
         [0042]    Immediately before injecting medication into a patient, the RNS  40 , as depicted in  FIG. 5 , is removed by squeezing the RNS removal tool  50 , which collapses along two slits  52  that run along the side of the tool  50  starting at its proximal end  55 . The collapsed configuration of the tool  50  allows the retention barbs  54  at the proximal end  55  to disengage from the corresponding retention windows  62  in the main body  60  of the device  10 . An inwardly projecting capture lip  75 , at the proximal inside surface of the RNS removal tool  50 , grasps the proximal edge  42  of the RNS  40 , which in combination with the compressive force transmitted by the collapsed RNS removal tool  50  walls allows it to pull the RNS  40  from the distal end of the syringe  20  when the user pulls it in a distal direction (see  FIGS. 5 ,  16  and  17 ). 
         [0043]    As the RNS removal tool  50  is withdrawn from the end of the device  10 , the needle guard body  80  slides forward, as shown in  FIG. 6 , to an intermediate stop point B as shown in  FIGS. 4A and 4C , governed by the interference between one or more inwardly projecting protrusions  64  from the main body  60  and corresponding grooves  90  in the outer surface of the needle guard body  80 . The outer side of one protrusion  64  on the main body  60  is shown in  FIG. 3 ,  4 B- 4 E,  5  and  6 . They are positioned at the end of cut-out sections that provide flexibility to the protrusions arms  65 . The protrusions  64  interfere with the needle guard body grooves  90  by projecting into the groove space and controlling the movement of the needle guard body  80  against the distally directed force of the spring  61  and the proximally directed reaction force from the patient&#39;s skin. 
         [0044]    Prior to removal of the RNS  40 , the protrusion  64  is in position A of the needle guard body grooves  90  as shown in  FIGS. 4A and 4B . After the RNS  40  is removed, the needle guard body  80  moves distally in response to the force of the spring  61 , so that the protrusion  64  travels along a first groove section  91  to position B as shown in  FIG. 4C . This includes some rotational movement of the needle guard body  80  as the protrusion  64  pushes against the angled wall of the first groove section  91  just before position B. This transition to position B includes a step  92  prior to groove deepening of the guard body groove  90  just prior to entering position B in a second groove section  93  to prevent the protrusion  64  from retracing its path back along the first groove section  91  toward position A. 
         [0045]    As the needle  24  is inserted into the patient, the patient&#39;s skin pushes the needle guard body  80  proximally against the force of the spring  61 , such that the groove-protrusion  90 - 64  interface moves from position B along the second groove section  93  to position C as shown in  FIG. 4A . Toward the distal end of the second groove section  93 , the groove depth steps down to a fourth, deeper groove section  94  along an edge  96  that is angled to the axis of the needle guard body  80 . At this point, the user must hold the device  10  against the skin working against the force of the spring  61  and perform the injection. 
         [0046]    After the injection is complete and the device  10  is pulled away from the patient, the needle guard body  80  moves distally, as shown in  FIG. 4D , under the force of the spring  61  from position C to position D with the protrusions  64  in the deeper groove section  94  such that the protrusions  64  encounter the stepped surface  96  causing the needle guard body  80  to rotate with respect to the main body  60  and enter a final groove section  98  in route to position D. As shown in  FIGS. 4A ,  4 E and  4 F, upon further distal movement of the needle guard body  80 , the protrusion  64  drops into a further deepening of the groove  90  at a groove recess  99  such that the protrusion  64  is substantially captured in the groove recess  99  in a locked out state. This engagement prevents relative motion of the needle guard body  80  with respect to the main body  60 . 
         [0047]    As the needle guard body  80  moves from position C to position D as the needle  24  is pulled from the patient, it is projected distally around the needle  24  to the extent that it protects the caregiver and others from inadvertently being stuck by the needle tip  25 . As shown in  FIGS. 4E and 4F , the needle guard body  80  is held in this needle-shielding position by interference of the protrusions  64  in the groove recess  99  at position D so that the needle guard body  80  cannot be pushed proximally with respect to the main body  60 , or pulled distally with respect to the main body  60 . 
         [0048]    For patients that have limited hand strength, holding the device against the skin while the needle  24  is in the injection site, requires maintaining a force against the spring  61  that pushes against the needle guard body  80  (position C in  FIG. 4A ). An alternative embodiment of the device to lessen this axial force could be accomplished by increasing the angle of the stepped surface  96  in the deeper groove section  94  that starts proximally to point C as shown in  FIGS. 4A and 4D  and deflects the main body protrusion  64  over to the straight groove section  98  that ends at position D. In  FIGS. 4A and 4D , this angle is shown at about 45 degrees. An angle of perhaps 60 degrees would place a greater axial component of force against the spring force at some reduction of the lateral force. Of course, an angle of 90 degrees would hold the needle guard body  80  completely against the force of the spring  61  if the main body protrusion  64  could stay down in the deeper groove section  94 , but there would be no lateral deflection to get the main body protrusion  64  over to position D where the device  10  locks out into the desired safety configuration. Depending on the coefficient of friction between the main body protrusion  64  and the needle guard body  80 , the angle can be optimized to reduce the holding force for the patient, but still allow the main body protrusion  64  to lockout at position D shown in  FIGS. 4A ,  4 E and  4 F. 
         [0049]    The sequence of steps to operate the device is described in  FIGS. 5 through 10 . First, as shown in  FIG. 5 , the RNS removal tool  50  is squeezed and pulled distally to remove the RNS  40  from the device. Squeezing the RNS removal tool  50  disengages the retention barbs  54  from the barb retention windows  62  and the capture lips  75  grip the proximal end of the RNS  40 , thus removing the RNS  40  as the RNS removal tool  50  is pulled distally outward from the device. As a result of the removal of the RNS  40  and the RNS removal tool  50 , the needle guard body  80  moves distally to the position shown in  FIG. 6 , under the force of the spring  61 . 
         [0050]    A composite of 3 steps to inject medication is shown in  FIGS. 7 and 8 . In Step 1, the needle guard body  80  is placed against the patient&#39;s injection site  100 . In Step 2,the device  10  is pushed against the injection site  100 , causing the needle guard body  80  to move proximally with respect to the main body  60  allowing the needle  24  to enter into the injection site  100 . In Step 3, the plunger rod  22  is pushed forward to dispel the medication into the injection site  100 .  FIG. 8  also shows a cross-section of the device  10  with the needle guard  80  fully retracted and after the plunger  22  has been fully depressed. 
         [0051]    In  FIG. 9 , the device  10  is being withdrawn from the injection site while the spring  61  pushes the needle guard body  80  distally. As the device  10  is fully withdrawn from the injection site  100 , the needle guard body  80  fully extends forward as shown in  FIG. 10 . At this point the main body protrusions  64  have entered position D in the groove  98  of the needle guard body  80  as shown in  FIGS. 4E and 4F  and locked the needle guard body  80  from further motion with respect to the main body  60  to prevent any needle sticks. 
         [0052]    To facilitate movement of the main body  60  and its protrusions  64  with respect to the grooves  90  of the needle guard body  80 , one or both components can be made using a plastic resin with ample lubrication (e.g. high content of mold release). Alternatively, dissimilar plastic resins exhibiting a low mutual coefficient of friction can be used for the components. 
         [0053]    It is to be understood that there exist alternative arrangements of components that would still fall within the scope of what is described and claimed within this application. For instance, the needle guard body  80  could be positioned on the outside of the main body with interior-facing grooves and outwardly facing protrusions on the main body  80 . 
         [0054]    An alternative embodiment for the safety device is presented for use with light-sensitive drugs that require only minimal exposure to light. In this embodiment, the components of the device are made of opaque materials (e.g. plastic resins with pigments, tinted glass, etc.) that effectively block light from reaching the drug in the medication delivery device. However, drug injection instructions normally require the caregiver to inspect the drug to check that it is not cloudy, etc. prior to giving the injection. To achieve this, as shown in  FIGS. 11 and 12  the main body  60  and needle guard body  80  of the device  10  have diametrically opposed windows that are positioned with respect to each other such that they are not aligned until the RNS removal tool  50  and RNS  40  have been removed. After removal, when the diametrically opposed windows on the two components align, as shown in  FIG. 12 , they form a line of sight through the device  10 , which enables the caregiver to inspect the drug volume. Referring to  FIG. 11 , prior to the removal of the RNS  40  and RNS removal tool  50 , the main body window  69  is blocked internally by the outer surface of the opaque needle guard body  80 . In  FIG. 12 , after the RNS  40  has been removed and the needle guard body  80  has moved forward, the window  69  of the main body  60  is aligned with the window  85  of the opaque needle guard body  80  allowing visibility into the syringe  20 . A similar window is provided on the diametrically opposite side of the device  10 . 
         [0055]    The RNS  40 , RNS removal tool  50 , and plunger rod  22  components would also be made of opaque materials to prevent light exposure at the ends of the device  10 . A covering (not shown) over the proximal end of the syringe with a hole for the plunger rod could also be created to provide additional light protection. Similarly, a second cover ( 158 ; see  FIG. 18A ) could be placed over the distal end of the RNS removal tool to block light from entering the distal end. 
         [0056]    The RNS  40  not only protects the needle  24  from being bent or its tip  25  from being damaged but it also forms one of the sterile barriers for the drug closure system. It must perform these functions before, during, and after sterilization and is therefore a complicated component that receives a tremendous amount of testing during the drug development and approval process. Since it has potential contact with the drug inside the syringe  20 , it becomes part of the specific drug closure system that receives regulatory approval and is therefore difficult to change after approval. They have become industry standard devices produced by specialized third party manufacturers. Nevertheless, they have limitations and deficiencies, namely that they can become difficult to remove from the syringe  20  after sterilization and storage, often requiring greater than 20N of force to remove. On a small part (approximately 0.25 inches in diameter, 1 inch long) such as this, it makes it difficult for healthcare workers to remove due to the small grasping area. Patients that perform self-administration, especially those with limited manual dexterity or strength (e.g. arthritic or multiple sclerosis patients) will find it extremely difficult to remove. Therefore, an added improvement of the present device  10  is to facilitate the RNS  40  removal. This is accomplished by the RNS removal tool  50 , which, as shown in  FIGS. 13 ,  14 ,  15 ,  23  and  24 , in addition to presenting a bigger surface area with which the user can grab, it also features some cam mechanisms to provide mechanical leverage in removing the RNS  40 . As depicted, the RNS removal tool retention barbs  54  reside inside the main body barb retention window  62  before the RNS  40  is removed. The lateral sides  110  of the barb  54  and the corresponding edges of the main body barb retention window  62  are angled, as shown in  FIG. 13 , such that as the RNS removal tool  50  is rotated, the barbs  54  push against the edge of the window  62  and are deflected radially inward as shown in  FIGS. 14 and 17 . The axial cam follower  56  on the RNS removal tool  50 , as shown in  FIG. 14 , has not yet acted against the main body axial cam profile  66 . 
         [0057]    The mechanical advantage of the barbs  54  engaging the edges of the retention windows  62  provides a strong radial squeeze so that the inwardly projecting capture lips  75  on the RNS removal tool  50  further engages the proximal edge  42  of the RNS  40  as shown in  FIGS. 17 and 22 . This engagement cannot pre-exist sufficiently since the syringe  20  and RNS  40  must assemble into the device  10 , from the proximal to distal end of device  10 , with minimal resistance or disturbance to the RNS  40  seal as shown in  FIG. 16 . After the proximal end  42  of the RNS  40  is engaged by the RNS removal tool  50 , the axial cam follower  56  engages a sloped surface  67  of the main body axial cam profile  66  as shown in  FIG. 15  which places a mechanically advantaged axial force on the RNS removal tool  50  in a distal direction, creating a distal axial displacement and forming a gap between the main body  60  and the RNA removal tool  50 . Because of the radial and axial cam surface between the RNS removal tool  50  and the main body  60 , the RNS removal tool  50  pushes the RNS  40  off of the syringe  20  and needle  24  with much less effort on the part of the user than would normally be required. 
         [0058]    Although this description has used a RNS  40  as an example, soft needle shields, which do not have a hard plastic outer shell, could equally be used in this application with minor changes to account for different geometry. 
         [0059]    A further improvement to the device could be a distal end cap  158  ( FIG. 18A ) on the RNS removal tool  50  and a proximal inwardly projecting lip (not shown) that together would help contain the RNS  40  after it had been removed from the syringe  20 , preventing it from falling to the floor, etc. 
         [0060]    The RNS removal tool  50  can also have large cut-through arrows  51  indicating the direction of rotation to the end user. It could also have large wings  53  extending radially outward to provide greater rotational mechanical advantage for the end user (see  FIG. 13 ). 
         [0061]    The RNS removal tool  50 , as described above, pulls the RNS  40  off the syringe/needle  24  by radially collapsing at the proximal end of the RNS  40 . When the RNS removal tool  50  has completely pulled the RNS  40  off the syringe/needle  24  and the user relaxes their grip, the collapsed capture of the proximal end of the RNS  40  may no longer be present allowing the RNS  40  to unexpectedly separate and fall from the RNS removal tool  50 . An improved version of the RNS removal tool  150  is shown in  FIGS. 18A and 18B , wherein an elastomeric insert  157  is placed inside the RNS removal tool  150  such that it nominally has a slight press fit against the RNS  40 , the fit being moderate enough to allow for installation of the RNS  40  from the proximal direction during syringe  20  insertion yet sufficient enough to maintain a frictional grip on the RNS  40  to prevent it from separating from the RNS removal tool  150  in the absence of any collapsing grip from the RNS removal tool  150 . The size and durometer of the elastomeric insert  157  is such that when the RNS removal tool  150  is rotated as in  FIG. 14 , the radial squeezing of the RNS removal tool  150  transmits a sufficient squeezing force against the RNS  40  through the elastomeric insert  157  so as to pull the RNS  40  from the syringe/needle  24 . Internal circumferential ribs may assist for transmitting a gripping force onto the RNS  40 . 
         [0062]    For those applications where full inspection of the syringe drug contents is required before injection, the main body window  69  shown in  FIG. 11  can be elongated the amount of the syringe body as shown in  FIG. 19 . This would also require that the needle guard body  80  be transparent or have a corresponding window since the drug inspection may need to occur before the device is readied for administration. 
         [0063]    In an alternate embodiment shown in  FIGS. 20-24 , the capture lip  75  of the RNS removal tool  50 , may come up over the syringe barrel  20  slightly when the device  10  is fully assembled. Consequently, when the RNS removal tool  50  is rotated during rigid needle shield  40  removal, the cam surface  110  on the RNS retention barbs  54 , presses against the main body retention window  62 , forcing the RNS removal tool arms  58  to press radially inward, causing the RNS removal tool capture lip  75  to press against the barrel of the syringe  20  rather than the RNS  40 . This is advantageous during the rotational portion of RNS  40  removal to avoid rotation of the soft needle shield  46  with respect to the syringe needle, which can affect the quality or sharpness of the needle prior to insertion into a patient. In this embodiment, as the RNS removal tool capture lip  75  presses against the barrel of the syringe  20  as it is rotated, the friction created between the two components will impart a force on the barrel of the syringe  20  to encourage rotation of the entire syringe—RNS assembly  200  ( FIG. 25 ). It is expected that either the syringe—RNS assembly  200  will rotate with the RNS removal tool  50 , or due to the friction between the syringe flange  34 , spring  61 , and main body  60  ( FIG. 26 ), the syringe—RNS assembly  200  will remain fixed and the RNS removal tool  50  will rotate around it. 
         [0064]    As the RNS removal tool  50  rotates the axial cam follower  56  will encounter the main body axial cam profile  66  forcing the RNS removal tool  50  to move axially away from the syringe  20 . Once the axial cam follower  56  on the RNS removal tool  50  reaches the end of the main body axial cam profile  66  the user will be required to continue to pull the RNS removal tool  50  from the device  10 , which will be aided by the needle guard body  80 , powered by the spring  61 . 
         [0065]    As the RNS removal tool  50  is moving axially away from the syringe  20 , the RNS removal tool capture lip  75  will be pressed against the barrel of the syringe  20  ( FIG. 21 ). It will continue to remain in contact with the syringe  20 , even as it reaches the syringe neck down area  28 . Consequently, the RNS removal tool capture lip  75  will capture the RNS  40  as the RNS removal tool  50  is removed from the device  10  ( FIG. 22 ). By captured, it is meant that the surface of the RNS removal tool capture lips  75  will slide radially inward and over the proximal end surface  42  of the RNS  40 . As the RNS removal tool  50  is removed from the device  10  it will pull the RNS  40  axially from the syringe  20 , ultimately removing it from the syringe  20 . 
         [0066]    In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention. For example, the reader is to understand that the specific ordering and combination of process actions described herein is merely illustrative, unless otherwise stated, and the invention can be performed using different or additional process actions, or a different combination or ordering of process actions. As another example, each feature of one embodiment can be mixed and matched with other features shown in other embodiments. Features and processes known to those of ordinary skill may similarly be incorporated as desired. Additionally and obviously, features may be added or subtracted as desired. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents.

Technology Classification (CPC): 0