Patent Publication Number: US-2023141155-A1

Title: Passive safety needle shield

Description:
PRIORITY CLAIM 
     This application is a continuation patent application of U.S. application Ser. No. 16/498,559, filed Nov. 27, 2019, which is a U.S.  371  National Stage of PCT International Application No. PCT/US2018/028394, filed Apr. 19, 2018, which claims the benefit of and priority to U.S. Provisional Application No. 62/488,006 filed Apr. 20, 2017, the contents of each of which are hereby incorporated by reference in their entireties. 
    
    
     FIELD OF THE INVENTION 
     The present invention is directed to safety devices for needles, and in particular to a novel needle shield. 
     BACKGROUND OF THE INVENTION 
     Safety is an important consideration in the manufacture of needles, particularly for medical use. Another consideration is comfort level, or reducing the pain associated with using a needle. Often a small gauge needle is used for small dose deliveries of medication in order to minimize discomfort. However, smaller gauge needles are more prone to bending, buckling and kinking during use due if the insertion force is not coaxial with the needle.  FIG.  1   , for example, illustrates a small gauge pen needle  100  for attachment to a pen injector. As shown, during use the thin needle may become bent or kinked. Accordingly, there is a need to prevent small gauge needles from bending during use. Most existing safety products for needles require active safety, where the user would have to physically activate the safety mechanism. Embodiments of the present invention, as described herein function on a passive safety mechanism so that there is preferably no manual activation by the user. 
     In certain situations, as illustrated in  FIG.  2   , such as filling a syringe  200  from a vial  202  through a needle  204 , or inserting a needle  206  into the skin  208 , the orientation of the needle  206  is important. In these situations it would be helpful to provide a mechanism to increase the likelihood of inserting the needle at a desired angle, and decreasing the likelihood of needle bending. Finally, some patients wish to not see the needle penetrating their skin. 
     SUMMARY OF THE INVENTION 
     Exemplary embodiments of the present invention overcome the deficiencies discussed above, and provide additional benefits by providing a retraction mechanism and needle enclosure to displace the load on a needle and guide the needle during injection to help prevent bending and/or buckling. Additional embodiments prevent a needle from being used more than once by locking when the retraction mechanism returns to the pre-injection state. Embodiments of the present invention also address the preference of users to not see a needle enter their skin by enclosing the needle so that the user does not see the needle penetrating the skin. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       Further details, features and advantages of designs of the invention result from the following description of embodiment examples in reference to the associated drawings. 
         FIG.  1    illustrates a pen needle hub bending due to insertion force; 
         FIG.  2    illustrates a syringe being filled and a pen needle being inserted into skin; 
         FIGS.  3 A- 3 C  illustrate a needle shield according to a first exemplary embodiment of the present invention; 
         FIG.  4    illustrates the needle shield of  FIG.  3    as a replacement for a conventional needle shield; 
         FIG.  5    illustrates a second exemplary embodiment of the invention; 
         FIG.  6    illustrates a third exemplary embodiment of the invention; 
         FIG.  7    illustrates a fourth exemplary embodiment of the invention; 
         FIG.  8    is a side view illustrating a telescoping exemplary embodiment of the invention; 
         FIG.  9    is a top view of the embodiment of  FIG.  8   ; 
         FIG.  10    is a cross-sectional view of the embodiment of  FIG.  8   ; 
         FIG.  11    illustrates a snap hook for use with a locking embodiment of the present invention; 
         FIG.  12    illustrates a locking embodiment in a first configuration; 
         FIG.  13    illustrates a locking embodiment in a second configuration; and 
         FIG.  14    illustrates a split-arm embodiment of the present invention. 
       Throughout the drawings, like reference numbers should be understood to represent like elements, features and structures. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An exemplary embodiments of the present invention is illustrated in  FIGS.  3 A- 3 C .  FIG.  3 A  shows a standard pen needle for which exemplary embodiments of the present invention are useful.  FIGS.  3 B- 3 C  illustrate a needle shield  300  that is added to a pen needle  100  to form an auto-retractable mechanism. As initially configured, the needle shield  300  is connected to the post  110  of the pen needle  100  at a base  302  of the needle shield  300 . The end of the needle  112  is contained within an enclosure housing  304 . Base  302  and enclosure housing  304  are connected by a hinged arm  306 . The needle shield  300  is preferably formed of a preloaded plastic mold, such as polypropylene or the like. As shown in  FIG.  3 B , in the initial state, the needle end  112  is hidden within the enclosure housing  304 . When the needle is inserted, the enclosure housing  304  slides down the needle towards needle post  110  as the needle penetrates the skin. The hinged arm  306  bends to accommodate this sliding motion. Then, as the patient pulls the needle out, elastic force of the hinged arm  306  pushes the enclosure housing  304  back to the end of the needle. Accordingly, the needle tip advantageously remains hidden in enclosure housing  304  to prevent accidental needle sticks and to provide comfort to patients who do not wish to see the needle penetration. The hinged arm  306  and enclosure housing  204  also combine to displace the buckling load off of the needle to prevent it from bending during use, in addition to guiding it in a straighter line through the enclosure housing. 
     Embodiments of the invention may advantageously be integrated with any injection product and provides a single-sided patient end safety that hides needle exposure throughout the entirety of the injection process. 
     The needle shield  300  is preferably formed from a preloaded plastic mold that converts preloaded potential energy into kinetic energy when force is applied to it during the skin penetration. This converted energy allows the shield to auto-retract into its original position to prevent any accidental needle sticks once the user pulls out the needle. Additionally, an auto-locking mechanism may be incorporated into the device to prevent re-use of needles on which the shield  300  is installed. The auto-locking mechanism advantageously activates once the device is retracted to its original position after a first insertion to prevent reuse and contamination. 
       FIG.  4    illustrates a conventional pen needle  400  with a conventional needle shield  402 , and also a pen needle  400  with an embodiment of the present invention  404  replacing the conventional shield  402 . 
     Additional exemplary embodiments of the invention are illustrated in  FIGS.  5 - 7   , to demonstrate the various changes and modifications may be made to the first embodiment described above without departing from the scope and spirit of the invention. Each of these embodiments are illustrated in use with a pen needle, but those of ordinary skill in the art will readily appreciate that embodiments of the invention may be utilized with any needle. Device  500  comprises a connecting member  502  that is fixed to a proximal end of the needle  504 . The connecting member  502  may be fixed to the needle by way of connection to the post  506  of the pen needle hub  508 , or by direct attachment to the proximal end of the needle  504 , or by any other suitable means. A first arm  510  is hingedly connected to the connecting member  502 , and extends axially away from the needle as illustrated. The first arm  510  is hinged at its other end to a second arm  512 . The second arm  512  is hinged at its other end to a movable member  514 . The movable member  514  is slidably attached to the needle. The connecting member  502 , first arm  510 , second arm  512 , and movable member  514  make up the protective shield  500 . The shield  500  is biased in the extended position, so that it contracts during injection, and extends again as the needle is withdrawn. The movable member  514  preferably contacts the skin during needle insertion and provides a guide for the needle, improving insertion performance. The movable member  514  preferably encapsulates the distal end of the needle  516  to provide protection from accidental sticks prior to and after use, and if desired a locking mechanism (not shown) can be incorporated to lock the device and prevent a second use. 
     Needle shield  600  is illustrated in  FIG.  6   . Needle shield  600  is substantially similar to the prior described embodiment  500 , but includes a bias housing  602  between the first arm  610  and second arm  612  to provide movement of the second arm  612  in and out within the bias housing  602  as the movable member  614  slides along the needle length. 
     Needle shield  700  is illustrated in  FIG.  7   . Needle shield  700  provides a single curved arm  702  fixed at a proximal end of the needle  704 , and connected slidably to the distal end of the needle  716 . 
     Another needle shield embodiment  800  is illustrated in  FIGS.  8 - 10   . This embodiment  800  advantageously entirely encases the needle. Needle shield  800  comprises a series of nested sections  802  that are biased or spring loaded in the extended position. Upon insertion of the needle, the nested parts collapse to expose the needle, but remain pressed against the skin so that the needle remains unseen to the user. Upon withdrawal of the needle, the nested sections  802  extend again to encapsulate the needle. A side view of the nested sections are illustrated in  FIG.  8    in a series of views ranging from fully extended to fully collapsed (needle inserted).  FIG.  9    is a top elevation view of the needle shield  800 .  FIG.  9    is a cross sectional side view illustrating the needle shield  800  in the extended initial position, and in the collapsed position. The distal most section  802  is preferably connected to a spring or other biasing means so that the nested section  802  extend to the extended position as the needle is withdrawn. 
     A locking mechanism for use with the needle shields described herein will now be described in connection with  FIGS.  11 - 13   .  FIG.  11    illustrates a snap hook  1100  for use in a locking mechanism. The snap hook includes a plurality of barbs  1102  oriented to point inward and downward, leaving a space smaller than the gauge of the needle with which the locking mechanism will be used.  FIG.  12    illustrates a needle shield  1200  incorporating a locking mechanism. As illustrated the snap hook  1100  is initially located at the proximal end of the needle. When the needle is used, the enclosure housing  1202  slides down the needle and engages the snap hook  1100 . Tabs  1104  are provided on the snap hook  1100  to lock the snap hook into the enclosure housing  1202  the first time the needle is fully inserted, that is, the first time the enclosure housing  1202  slides all the way to the proximal end of the needle. Once the snap hook  1100  has locked into the enclosure housing  1202 , and the needle is withdrawn, the enclosure housing  1202  returns to the distal end of the needle, and draws the snap hook  1100  with it. When Snap hook reaches the distal end of the needle, the barbs  1102  naturally flex inwards, and thus interfere with the needle if needle insertion is attempted again. 
       FIG.  14    illustrates yet another embodiment of the needle shield  1400 . In this embodiment the first  1402  and second  1404  arms are split to form two pairs of arms. 
     The above describe embodiments are intended to be illustrative of embodiments of the invention without being limiting. Those of ordinary skill in the art will readily appreciate that various changes and modifications to the embodiments described herein may be made without departing from the scope and spirit of the invention as described and illustrated herein.