Patent Publication Number: US-11638787-B2

Title: Safety device for preventing needle stick injury with a needle of a medical device and medical device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. application Ser. No. 15/571,958, filed Nov. 6, 2017, which is the United States national stage entry of International Application Serial No. PCT/EP2016/062875, filed Jun. 7, 2016, and claims priority to European Patent Application No. 15305866.4, filed Jun. 8, 2015, and European Patent Application No. 15306800.2, filed Nov. 13, 2015, the entire disclosures of each of which are hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present disclosure relates to a safety device for preventing needle stick injury with a needle of a medical device. The present disclosure also relates to a medical device including such a safety device. 
     Description of Related Art 
     In this application, the distal end of a component or apparatus must be understood as meaning the end furthest from the hand of the user and the proximal end must be understood as meaning the end closest to the hand of the user, with reference to the medical injection device intended to be used with said component or apparatus. As such, in this application, the distal direction must be understood as the direction of injection with reference to the medical device, and the proximal direction is the opposite direction to said direction of injection. 
     Medical devices provided with sharp pointed needles are of daily practice among the medical community in order to perform injections or to take samples into or from muscles, veins or arteries. They can be injection devices such as syringes, pen-injectors, catheters or blood collection devices. Sharp pointed needles present an inherent risk of needle stick injury for the medical staff and the patients and are thus usually provided with a needle cap covering the needle before use. This cap not only preserves the needle from contamination but also from undesired contacts or punctures that could occur during transport and delivery by the medical staff. Obviously, such a cap needs to be removed immediately before use of the medical device. 
     However, replacing the needle cap onto the needle after use is strictly prohibited as it is regarded as a major cause of accident and contamination for the medical staff. Indeed, the whole medical device or at least the used needle should be disposed after use in an appropriate needle collector. However, a risk of needle stick injury still exists as the medical staff handles the bare, contaminated needles before disposal. 
     Safety devices have thus been designed to prevent needle stick injury with the needle of such medical devices after use i.e. between the end of the injection or collection and the proper disposal of the device. Usually, such safety systems are designed to be locked automatically or manually on at least the needle point when the medical act is finished. 
     Nevertheless, many of these safety systems required a triggering step in order to expose the needle point before use, which slows down the pace of the medical act and decreases the safety level of the medical device. In addition, the majority of such safety systems increase the overall size of the device leading to difficult handling but also to storage concerns particularly for prefilled syringes. Finally, most of these systems do not achieve a complete exposure of the needle point and impede the medical act by preventing direct view and access to the needle point. 
     Additionally, prefillable syringes are transported in sterile packaging after manufacturing in order to be filled by the pharmaceutical companies with a pharmaceutical product before the final delivery to the medical staff. The sterile packaging is adapted to the length and diameter of the syringe closed with a usual needle cap and may not accept oversized safety devices as currently available. 
     SUMMARY OF THE INVENTION 
     Starting from the prior art, it is an object of the present disclosure to provide a safety device able to prevent needle stick injury with the needle of a medical device without requiring a triggering step before use and without impeding the medical act. It is a further object of the present disclosure to provide a safety device of appropriate size that has a diameter no greater than the syringe barrel and a limited length in order to be accommodated in a standard packaging used for prefillable syringes. 
     Accordingly, a safety device for preventing needle stick injury with a needle of a medical device is given, the needle including a proximal end fixed to a tip of the medical device and a distal end provided with a needle point. The safety device includes a protective cap adapted to be mounted on the tip of a medical device to at least cover the needle point, said protective cap including a proximal extremity provided with an engaging peg, and a shield adapted to be mounted by a pivot link around the tip of the medical device such that it may adopt a storage position where it is interlocked with the protective cap, a retracted position where it gives access to the needle and a safety position where it covers the needle, the shield including a cam surface at its proximal extremity. The cam surface and the engaging peg are located proximally from the pivot link and arranged so that, when the safety device is mounted around the tip of a medical device, removing the protective cap from the tip by a distal movement shifts the shield from the storage position to the retracted position. 
     The pivotal mounting of the shield as well as the engagement of the engaging peg of the protective cap with the cam surface of the shield allow a passive opening of the shield into the retracted position in order to give a full access to the needle point. In this way, the removal movement of the protective cap from the tip yields to the rotation of the shield from the storage position to the retracted position, the engagement between the engaging peg and the cam surface transforming an axial movement into a rotational movement. No additional triggering step is thus required to use such a medical device provided with such a safety device: the medical act is not slow down and no training is required for the medical staff. The proximal location of the cam surface and the engaging peg as regards as the pivot link allows the shield to reach substantially a right angle with the needle when the shield is in the retracted position. This right angle is particularly valuable so as not to prevent a direct view of the needle by the medical staff and not to hamper the injection. The safety system of the present invention thus brings needle stick prevention to medical staff with no or limited impact on the medical practice, thus optimizing the acceptance of such a safety system by medical professionals. 
     Furthermore, the interlocking of the protective cap and the shield leads to a compact and small size device, with an external diameter of the safety device no greater than the external diameter of the medical device. This is particularly valuable when the medical device is a prefillable syringe as standard packaging used for devices storage does not accept oversized safety systems. Prefillable syringes may thus be equipped with such a safety system immediately after manufacturing packaged in standard existing packaging and then directly shipped to the pharmaceutical company. In this way, the filling process performed by pharmaceutical companies may not be affected by the presence of the safety device. 
     In a preferred embodiment, the shield is provided with two cam surfaces and the protective cap is provided with two engaging pegs. Such an embodiment allows a more reliable passive opening of the shield when the protective cap is removed from the tip. 
     In a further preferred embodiment, the shield is provided with two proximal legs, each leg including a buckle. The safety system further includes a mounting ring adapted to be mounted onto the tip of the medical device and provided with two opposing inserts. The opposite inserts are adapted to be assembled with the buckles of the shield in a pivoting link so as to pivotally mount the shield to the tip when said mounting ring is arranged on the tip. This optional mounting ring is valuable for mounting the safety device on a tip which cannot be manufactured with the opposing inserts such as to form a pivot link with the shield. This is the case for example with glass syringes, as the tip is made by glass forming which is not an appropriate technique to elaborate tiny features such as opposite inserts. 
     In a preferred embodiment, the shield is further provided with a hook such that, when the safety device is mounted on the tip of a medical device and the shield is in the safety position, said hook is able to irreversibly lock said shield onto the needle. The hook therefore contributes to the safety position of the shield by preventing the shield to move back to the retracted position, thus protecting patients and medical staff from needle stick injury. 
     In a further preferred embodiment, the protective cap further includes a proximal radial opening positioned and dimensioned to accommodate the hook of the shield when the shield is in the storage position. This proximal radial opening allows for an optimal interlocking between the shield and the protective cap and thus for a small sized safety device showing a size similar to a usual needle cap. This small sized safety device may thus be accommodated into a standard sterile packaging commonly used for prefillable syringes. 
     In a further preferred embodiment, the shield is further provided with a notch, so that, when the safety device is mounted on the tip of a medical device and the shield is in the safety position, the notch hides the needle point. The notch therefore contributes to the safety position of the shield by masking the needle point, thus preventing any access to it and then protecting patients and medical staff from needle stick injury. 
     In a further preferred embodiment, the protective cap further includes a distal radial opening positioned and dimensioned to accommodate the notch of the shield when the shield is in the storage position. This distal radial opening allows an optimal interlocking between the shield and the protective cap and thus leads to a small sized safety device adapted to prefillable syringes. 
     In a further embodiment, a medical device is given, which includes a tip provided with a needle including a proximal end fixed to the tip of the medical device and a distal end provided with a needle point. The medical device further includes a safety device as mentioned above. Such a medical device provides a high level of safety to the medical staff and the patients when the safety device is placed in the safety position after use. Furthermore, as the safety device is passively opened from the storage position to the retracted position by removing the protective cap, no specific medical instructions are required to use it. Besides, as such a medical device presents a similar size as a current existing medical device without a safety device, it may be assembled and stored in a standard packaging before shipping to a pharmaceutical company for future filling with a medical composition. A safe medical device may thus be provided to the medical staff without any change in the filling process of the pharmaceutical company. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred further embodiments and aspects of the present disclosure are explained further by the following description of the Figures: 
         FIG.  1    shows an example of a medical device in the form of a syringe. 
         FIG.  2    shows an example of a medical device provided with a safety device according to the present disclosure. 
         FIGS.  3 A and  3 B  are respectively a top view and a perspective view of a mounting ring according to the present disclosure. 
         FIG.  4    is an example of a medical device provided with the mounting ring of  FIGS.  3 A and  3 B . 
         FIGS.  5 A and  5 B  are respectively a perspective view and a top view of a shield according to the present disclosure. 
         FIG.  6    is a perspective view of a mounting ring according to  FIGS.  3 A and  3 B  assembled with a shield according to  FIGS.  5 A and  5 B . 
         FIGS.  7 A and  7 B  are a top view and a perspective view of a protective cap according to the present disclosure. 
         FIGS.  8 A,  8 B and  8 C  are respectively a cross-section view, a top view and a perspective view of a sealing cap according to the present disclosure. 
         FIGS.  9 A and  9 B  are respectively a cross-section view and a side view of a protective cap according to  FIGS.  7 A and  7 B  provided with a sealing cap according to  FIGS.  8 A- 8 C . 
         FIGS.  10 A,  10 B and  10 C  are respectively a cross-section view, a top view and a side view of an example of a safety device according to the present disclosure including the mounting ring of  FIGS.  3 A and  3 B , the shield according to  FIGS.  5 A and  5 B , the protective cap of  FIGS.  7 A and  7 B  and the sealing cap of  FIGS.  8 A- 8 C . 
         FIGS.  11 A- 11 F  are side views of a safety device according to  FIGS.  10 A- 10 C  provided on the medical device of  FIG.  1    at each step of use. 
         FIGS.  12 A- 12 F  are cross-section views of a safety device according to  FIGS.  10 A- 10 C  provided on the medical device of  FIG.  1    at each step of use. 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
       FIG.  1    discloses a syringe  10  as an example of a medical device according to the present disclosure. The syringe  10  includes a longitudinal barrel  11  defining a reservoir  12 , the longitudinal barrel  11  having an open proximal end defining a flange  13  and a restricted distal end defining a longitudinal tip  14  provided with a needle  20 . The syringe  10  may be in glass or in plastic, the following disclosure mainly considering a glass syringe. Other medical devices may be pen-injectors or autoinjectors. 
     The needle  20  includes a longitudinal tube  21 , a proximal open end stacked or glued in the longitudinal tip  14  and a distal open end comprising a needle point  22 . 
     Referring to  FIG.  2   , the syringe  10  is provided with a safety device  100  including a mounting ring  110 , a shield  120  and a sealing cap  130 . 
       FIGS.  3 A and  3 B  disclose an example of a mounting ring  110 . The mounting ring includes a cylindrical body  111  provided with proximal mounting fingers  112  separated by voids  113  and two opposite inserts  114  (only one visible in  FIG.  2 B ). 
     The proximal mounting fingers  113  allow for the arrangement of the mounting ring  110  onto the longitudinal tip  14  of the syringe  10 , as visible in  FIG.  4   . The mounting ring  110  is preferably made of any rigid polymer adapted to medical use, such as high density polyethylene (PE), polypropylene (PP), polycarbonate (PC), acrylonitrile butadiene styrene (ABS), polyoxymethylene (POM), polystyrene (PS), polybutylene terephthalate (PBT), polyamide (PA), and their combinations. The mounting ring  110  may also be made of a medical-grade metal such as steel. 
       FIGS.  5 A and  5 B  disclose a shield  120  including a distal projection  121  and a proximal portion  122 , the distal projection being provided with a notch  123  intended to accommodate at least the needle point  22  of a needle  20  and a hook  124  intended for locking onto the longitudinal tube  21  of the needle  20 , when the shield  120  is mounted on the longitudinal tip of a syringe. The shield  120  is further provided in its proximal portion  122  with two proximal legs  125 , each leg including a buckle  126  and a cam surface  127 . The buckles  126  are intended to be assembled with the inserts  114  of the mounting ring  110  in a pivoting link as visible in  FIG.  6   , the mounting ring  110  being accommodated in the proximal portion  122  of the shield  120 . The shield  120  may be made in the same material as the mounting ring  110 . It can be either opaque or transparent. 
     The mounting ring  110  may thus allows a pivotal mounting of the shield  120  to the tip  14  of a syringe  10  when it is not possible to have inserts directly on the tip  14 , for example when the syringe  10  is made of glass. However, plastic syringes or injectors may be manufactured with integrated inserts allowing a mounting pivotally the shield  120  directly to the tip  14  without the need of a mounting ring  110 . Alternatively, the pivot link between the shield  120  and the mounting ring  110  or the tip  14  may be a plastic hinge i.e. a flexible plastic link allowing a rotative movement between the shield  120  and the mounting ring  110  or the tip  14 . 
     A protective cap  130  according to the present disclosure is visible in  FIGS.  7 A- 7 B . It includes a tubular body  131  with an inner cavity  132 , a distal radial opening  133  and a top proximal extension  134  contiguous to the distal radial opening  133 . The top proximal extension  134  is provided with a proximal radial opening  134 A, a shoulder  134 B and a proximal portion  134 C. The top proximal extension  134  is substantially parallel to an opposite bottom proximal extension  135  provided with two curved cuts  136  and two engaging pegs  137 . Both the top proximal extension  134  and the bottom proximal extension  135  show a curvature radius so as to respect the globally tubular shape of the body  131 . The protective cap  130  may be made in the same material as the mounting ring  110 . It can be either opaque or transparent. 
     Now referring to  FIGS.  8 A- 8 C , an optional sealing cap  140  is described. This sealing cap  140  includes a cylindrical body  141  and an inner cavity  142 . The inner cavity  142  has globally a conical shape and is intended to accommodate the longitudinal tip  14  and the needle  20  of the syringe  10 . On its top portion, the sealing cap includes a distal radial recess  143  and a proximal radial opening  144 , while it includes two opposite transversal surfaces  145  on its proximal portion. 
     The sealing cap  140  is dimensioned to be accommodated inside the inner cavity  132  of the protective cap  130  (see  FIGS.  9 A and  9 B ). Once assembled the distal radial recess  143  of the sealing cap  140  faces and closes the distal radial opening  133  of the protective cap  130 . Similarly, the proximal radial opening  144  of the sealing cap  140  faces the proximal radial opening  134 A of the protective cap  130 . The opposite proximal surfaces  145  and the internal surface of the distal radial recess  143  are the only portions of the sealing cap  140  visible when the sealing cap  140  is inserted into the protective cap  130 . 
     The sealing cap  140  may be valuable to seal the needle point  22  of a prefilled syringe by pricking the needle point  22  into the material of the sealing cap  140 , as visible in  FIG.  12 A . To this end, the material of the sealing cap may be a thermoset or thermoplastic elastomer such as poly(ethylene-propylene-diene) monomer (EPDM), poly(styrene-butadiene) rubber (SBR), isopropylene isobutylene rubber (IIR), polystyrene-b-poly(ethylene-butylene)-b-polystyrene (SEBS), polystyrene-b-polybutadiene-b-polystyrene (SBS), nitrile butadiene rubber (NBR), natural rubber (NR), isoprene rubber (IR) or butadiene rubber (BR) or combination thereof. 
     The protective cap  130  is designed to be complementary and interlocked with the shield  120  and the mounting ring  110 , in a storage position as visible in  FIGS.  10 A- 10 C . The extension  121  of the shield  120  is totally accommodated between the distal radial opening  133 , the shoulder  134 B of the protective cap  130 , the notch  123  of the shield  120  being accommodated in the distal radial opening  133  of the protective cap  130 . In addition, the hook  124  of the shield  120  is accommodated into the proximal radial opening  134 A of the protective cap  130  and the top and bottom proximal extensions  134 ,  135  overlap the mounting ring  110  that is pivotally connected to the shield  120 . Furthermore, the shield  120  and the protective cap  130  are dimensioned and interlocked such that the two curved cuts  136  of the protective cap  130  accommodate the cam surfaces  127  while the two engaging pegs  137  of the protective cap  130  engage the cam surfaces  127  of the shield  120 , as visible in  FIG.  10 C . 
     The protective cap  130 , the shield  120 , optionally the mounting ring  110  and the sealing cap  140  are thus totally interlocked in an example of a safety device  100  according to the present disclosure. Such a safety device  100  can be provided as a pre-assembled sub-unit for a straightforward mounting on the longitudinal tip  14  of a syringe  10 . The mounting step may be done by a single-step by application of a fitting transversal force for arrangement of the safety device  100  onto the longitudinal tip  14  of the syringe  10 . 
     The operating process for using a safety device  100  will now be described with reference to  FIGS.  11 A to  11 F and  12 A to  12 F . A syringe  10  is presented with a safety device  100  to the medical staff according to  FIGS.  11 A and  12 A : the safety device  100  is mounted onto the longitudinal tip  14  of the syringe  10 , the shield  120  is in the storage position, interlocked with the protective cap  130  and substantially parallel to the needle  20 , which is enclosed by the protective cap  130 . Furthermore, the needle point  22  is embedded in the elastomeric material of the elastomeric inner cap  140  avoiding any leakage of the contents of the reservoir  12  of the syringe  10 , which is valuable when the syringe  10  has been prefilled with a medical product. The protective cap  130  is useful to protect the needle  20  prior use, for example from shocks, dusts and contact with any contaminations. The elastomeric inner cap  140  maintains the sterility and the sealing of the needle  20 . 
     In a first step, the medical staff may open the safety device  100  by pinching and drawing the protective cap  130  in the distal direction. As soon as the protective cap  130  moves distally, the engaging pegs  137  of the protective cap  130  push onto the cam surfaces  127  of the shield  120 , which results into a rotary, opening movement of the shield  120  towards the syringe barrel  11  as visible in  FIGS.  11 B and  12 B . The rotary movement of the cam surfaces  127  is optimized by the specific shapes of the curved cuts  136  which allow a smooth and natural movement, similar to the opening of a needle cap that does not have any safety devices. Because of this rotary movement, the hook  124  and the notch  123  of the shield  120  escapes respectively from the proximal radial opening  134 A and the distal radial opening  133  of the protective cap  130 . 
     In  FIGS.  11 C and  12 C , the opening of the protective cap  130  by distal translation is almost completed, the engaging pegs  137  being barely disengaged from the cam surfaces  127  and the needle  20  becoming visible. 
     In  FIGS.  11 D and  12 D , the safety device  100  is fully open since the protective cap  130  has been removed and the shield  120  has rotated into a retracted position. Thanks to the proximal position of the cam surfaces  127  and the engaging pegs  137  as regards as the pivot link made by the buckles  126  and the insert  114 , the shield  120  is doing substantially a right angle with the needle  20  after rotation and is giving full access to this needle  20 . The syringe  10  is now ready to be used, for example to inject a medical product into the body of a patient. Furthermore, the shield  120  in the retracted position does not prevent a direct view on the needle  20  and especially the needle point  22  which allows an injection in safe and comfortable conditions, both for patients and medical staff. 
     Once the injection is performed, the shield  120  may be moved to a safety position where it covers the needle  20  by applying a force with a thumb or a surface (see  FIGS.  11 E and  12 E ). The force yields to a rotation of the shield  120  toward the needle  20 , because of the pivoting link realized by the inserts  114  and the buckles  126 . This operation is safe for the medical staff as the thumb is protected by the shield from needle stick injury. 
     At the end of the rotating movement, the shield  120  covers the needle  20 , is further locked on the needle longitudinal tube  21  by the hook  124  and the needle point  22  is accommodated into the notch  123 , as visible in  FIGS.  11 F and  12 F . In this position, the needle point  22  is hidden by the notch  123  (see  FIG.  12 F ) and the shield  123  prevents any needle stick injury. 
     As applicable, all individual features that are shown in the individual embodiments can be combined and/or exchanged with each other without departing from the scope of the disclosure.