Patent Publication Number: US-2015080848-A1

Title: Puncturable membrane for safety syringe

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This applications claims the benefits of U.S. Provisional Patent Application Ser. No. 60/857,088, the entire contents of which are incorporated herein by reference. 
     The entire contents of U.S. application Ser. No. 11/511,668, filed Aug. 29, 2006 is expressly incorporated herein by reference. Additionally, the entire contents of U.S. Pat. No. 6,413,236, filed Jun. 20, 2000 to Van Dyke is expressly incorporated herein by reference. Also, the entire contents of U.S. application Ser. No. 11/409,617, filed Apr. 24, 2006 is expressly incorporated herein by reference. 
    
    
     STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT 
     Not Applicable 
     BACKGROUND 
     The present invention relates to a safety syringe wherein a variable fluid chamber is hermetically sealed off from contaminated ambient air until a needle assembly is attached to a syringe body such that fluidic medication may be withdrawn from a medication vial and injected into a patient in a sterile manner. 
       FIG. 1  illustrates a conventional safety syringe with a detached needle assembly. During use, a medical professional may select the appropriate sized needle based on the fluidic medication to be administered to the patient. Once the appropriate sized needle is selected, the needle assembly may be attached to the syringe body of the safety syringe. Unfortunately, a distal end of the syringe body is uncovered. As such, from the time that the syringe is removed from its packaging to the time that the needle assembly is attached to the syringe body, ambient air is allowed to flow into a variable fluid chamber which houses the fluidic medication right before the fluidic medication is injected into the patient. The ambient air flowed into the variable fluid chamber may contain viruses, bacteria or other unwanted contaminants which may he lodged onto the inner surface of the variable fluid chamber. When the fluidic medication is withdrawn into the variable fluid chamber, the contaminant lodged onto the inner surface of the variable fluid chamber may contaminate the fluidic medication to be injected into the patient. 
     Accordingly, there is a need in the art for a device and a method for injecting fluidic medication into the patient in a sterile manner. 
     BRIEF SUMMARY 
     The safety syringe discussed herein addresses the needs discussed above, discussed below and those that are known in the art. 
     The safety syringe provides a sterile environment in which the fluidic medication may be withdrawn from a medication container and subsequently injected into the patient. More particularly, the safety syringe may have a barrier disposed at a distal end portion of a syringe body of the syringe. The barrier provides an impermeable air barrier between the environment (contaminated ambient air)and the variable fluid chamber. The barrier may be punctured at or about the same time when a needle assembly is attached to the syringe body. When the barrier is punctured, the needle assembly then acts as a cover such that contaminated ambient air does not enter into the variable fluid chamber after the barrier is punctured by the needle assembly. As such, at no time during the process of removing the syringe from its packaging, attaching the needle assembly to the syringe body, withdrawing fluidic medication from a medication container and injecting the patient with the fluidic medication was the variable fluid chamber exposed or allowed to have ambient air flow therein. Hence, the fluidic medication injected into the patient is performed in a sterile manner. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which like numbers refer to like parts throughout, and in which: 
         FIG. 1  is a perspective view of a prior art safety syringe; 
         FIG. 2  is a perspective view of a safety syringe with a barrier and a detached needle assembly which is attachable to the syringe body; 
         FIG. 3  is a front cross-sectional view of the safety syringe shown in  FIG. 2 ; 
         FIG. 4  is an alternate embodiment. of attaching the harrier to the syringe body; 
         FIG. 5  is a bottom view of the barrier illustrating score lines forming eight pie-shaped pieces wherein the score lines are depressions formed in the barrier to control tearing, ripping or weakening of the barrier; 
         FIG. 6  illustrates the pie shaped pieces shown in  FIGS. 2 and 5  when the barrier is punctured by the needle assembly; 
         FIG. 7  is a bottom view of the barrier illustrating an alternate configuration of the score lines; 
         FIG. 8  is a bottom view of the barrier illustrating the score lines having a wavy configuration; and 
         FIG. 9  is a front cross-sectional view of a safety syringe wherein the barrier is attached to an inner surface of the syringe body. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings,  FIG. 2  is a perspective view of a safety syringe  10 . In particular, the safety syringe  10  may comprise a plunger assembly  12  partially disposed within a syringe body  14 . Finger platforms  16  may be attached to a proximal end of the syringe body  14  to assist the user in traversing the plunger assembly  12  between a retracted position and a forward position. The safety syringe  10  may also comprise a detached needle assembly  18  which may be attached to the syringe body. One benefit of having the needle assembly  18  initially detached from the syringe body  14  and a selected needle assembly  18  attachable to the syringe body is that a medical professional may attach an appropriately sized needle  20  to the syringe body  14  depending cm the particular mediation to be administered to the patient. 
     The safety syringe  10  is directed to a device and a method for maintaining sterility of fluidic medication during the entire process of withdrawing fluid medication from a medication container and injecting the fluidic medication to the patient. The safety syringe  10  accomplishes this by providing a barrier  22  between the environment which contains contaminated ambient air and a sterile variable fluid chamber  26 . 
     In particular, the safety syringe  10  may be provided to a medical professional. The needle assembly  18  may initially be detached from the syringe body  14 . Moreover, the plunger assembly  12  may be initially positioned in a retracted position when provided to the medical professional. As used herein, a retracted position of the plunger assembly is where a piston  28  of the plunger assembly  12  is closer to a proximal end of the syringe body  14  compared to a distal end portion  30  of the syringe body  14 . When the safety syringe  10  is assembled by the manufacturer, the safety syringe  10  is also sterilized to kill or eliminate harmful or potentially harmful viruses, bacteria and other unwanted contaminants that may be on or in the safety syringe  10 . More particularly, during the sterilization process, the inner surface of the variable fluid chamber  26  is sterilized. In particular, the inner surface of the variable fluid chamber  26  may be defined by a distal end  32  of the piston  28 , an inner surface  34  of the syringe body  14  and a proximal surface  36  of the barrier  22 . 
     In use, to administer a fluidic medication to a patient, the needle assembly  18  is attached to the distal end portion  30  of the syringe body  14 . At or about the same time, the barrier  22  is punctured to allow fluidic medication to be drawn into the variable fluid chamber  26  and subsequently ejected out of the variable fluid chamber  26  and injected into the patient via the needle  20 . 
     One of the many important aspects of the safety syringe  10  is that the inner surface of the variable fluid chamber  26  does not come into contact with the contaminated ambient air  24  during the process of attaching the needle assembly  18  to the syringe body  14 . Before the needle assembly  18  is attached to the syringe body  14 , the barrier  22  prevents contaminated ambient air  24  from entering into the variable fluid chamber  26 . The barrier  22  is punctured to allow fluid and/or air to enter into or escape out of the variable fluid chamber  26  at or about the same time that the needle assembly  18  is attached to the syringe body  14 . At such time, the needle assembly  18  then behaves as a cover after the barrier  22  is punctured such that ambient air does not enter into the variable fluid chamber  26  and possibly contaminate the variable fluid chamber  26  due to airborne viruses, bacteria or unwanted contaminants in the ambient air  24 . 
     After the needle assembly  18  is attached to the syringe body  14 , the fluidic medication may be withdrawn from a medication vial and be administered to the patient. In particular, the needle  20  of the syringe  10  may be inserted into a medication container or vial. At this time, the plunger assembly may be traversed toward the forward position. The forward position is defined where the piston  28  is closer to the distal end portion  30  of the syringe body  14  compared to a proximal end of the syringe body  14 . As the plunger assembly  12  is traversed toward the forward position, sterilized air contained in the variable fluid chamber  26  is transferred into the medication container. Such transfer of sterilized air  38  increases the pressure within the medication container to assist in withdrawal of the fluidic medication therefrom. The medication container and safety syringe  10  may now be inverted such that the medication container is positioned over the safety syringe  10 . A distal tip  40  of the needle  20  may be positioned within the fluidic medication contained in the medication container. Now the plunger assembly  12  may be traversed back toward the retracted position. Such retraction of the plunger assembly  12  traverses the fluidic medication contained in the medication container into the variable fluid chamber  26  of the safety syringe  10 , As you will note, the fluidic medication in the variable fluid chamber  26  was not exposed to ambient air  24 . The medical professional may remove the needle  20  from the medication container and remove any sterilized air  38  from within the variable fluid chamber by inverting the safety syringe  10 , tapping on syringe body  14  to urge the sterilized air  38  toward the needle  20 , and then slightly traversing the plunger assembly  12  toward the forward position to eject the sterilized air  38  and a negligible amount of the fluidic medication out of the variable fluid chamber  26  and the needle assembly  18 . At this time, the medical professional may inject the patient with the fluidic medication contained in the variable fluid chamber  26 . 
     In an aspect of the safety syringe  10 , the needle assembly  18  may be attachable to the to the syringe body  14  in a plurality of different methods known in the art, discussed herein and those that are developed in the future. By way of example and not limitation, as shown in  FIG. 3 , the needle assembly  18  may have threads  42  disposed at a proximal end portion  44  of the needle assembly  18 . Mating threads  46  may be formed at the distal end portion  30  of the syringe body  14 . More particularly, the mating threads  46  may he firmed on an inner surface  34  of the syringe body  14 , whereas, the threads  42  of the needle assembly  18  may be formed on an outer surface of the proximal end portion  44  of the needle assembly  18 . To attach the needle assembly  18  to the syringe body  14 , the threads  42  may be threaded onto the mating threads  46 . To lock the needle assembly  18  onto the syringe body  14 , the needle assembly  18  may be formed with a stop flange  48 . As the needle assembly  18  is threaded into the syringe body  14 , the stop flange  48  may eventually contact the distal end portion  30  of the syringe body  14 . The needle assembly  18  may then be cinched or tightened onto the syringe body  14  to insure frictional attachment between the needle assembly  18  and the syringe body  14 . The above description of attaching the needle assembly  18  to the syringe body  14  is one embodiment of attaching the needle assembly  18  to the syringe body  14 . The safety syringe  10  discussed herein should not be limited only to this embodiment but also contemplates any other methods and embodiments. 
     In an aspect of the safety syringe  10 , various types of barriers  22  arc contemplated. By way of example and not limitation, as shown in  FIG. 3 , the barrier  22  may be an air impermeable membrane disposed over the distal end portion  30  of the syringe body  14 . The air impermeable membrane may he hermetically sealed about the outer periphery of the distal end portion  30  of the syringe body  14 . Such seal is identified as reference numeral  50  in  FIG. 3 . The seal  50  may be formed via cold adhesive, hot adhesive, sonic welding as well as other methods known in the art or developed in the future, The air impermeable membrane prevents non-sterile air of the environment from entering into the variable fluid chamber  26  after the safety syringe  10  is removed from its packaging and prior to mounting of the needle assembly  18  onto the syringe body  14 . 
     In another aspect of the safety syringe  10 , as shown in  FIG. 4 , the barrier  22  may be attached to the distal end  52  of the syringe body  14 . Such attachment may be made by cold adhesive, hot adhesive, sonic welding, as well as other methods that may be know in the art or developed in the future. The seal between the barrier  22  or air impermeable membrane and the distal end  52  of the syringe body  14  may be identified as reference numeral  54  in  FIG. 4 . 
     In an aspect of the safety syringe  10 , the puncturing of the barrier  22  may be controlled. In particular, as shown in  FIG. 2  and  FIG. 5 , the puncturable barrier  22  may have a plurality of score lines  56 . The score lines urge the puncturable barrier  22  to tear or weaken at the score lines  56  to permit fluid to pass through the barrier  22 . The score lines  56  may be depressions formed on a proximal or distal side of the barrier  22 . As shown in  FIG. 6 , when the needle assembly  18  (not shown in  FIG. 6 ) is attached to the syringe body  14 , pie-shaped pieces  58  of the harrier  22  are pushed into the variable fluid chamber  26 . The pie shaped pieces  58  are disposed between the threads  42  of the needle assembly  18  and the mating threads  46  of the syringe body  14 . Fluid (e.g., fluidic medication) may now pass into or out of the variable fluid chamber  26 . 
     Although the score lines  56  as shown in  FIG. 5  are formed as in a plurality of pie-shaped pieces  58 , other configurations of the score lines  56  are contemplated. By way of example and not limitation, the score lines  56  may be formed on the puncturable harrier  22  as shown in  FIG. 7 .  FIG. 8  shows an alternative embodiment of a different configuration of the score lines  56 . As shown, each score line  56  may have a wavy pattern. 
     In an aspect of the barrier  22 , the barrier  22  may be fabricated from an air impermeable material. By way of example and not limitation, the impermeable material may be plastic, paper, rubber, cloth, etc. The barrier  22  may be perforated but still be characterized as impermeable so long as a free flow of ambient air is not allowed to pass through the barrier  22  into the variable fluid chamber  26 . 
     In another aspect of the safety syringe  10 , as shown in  FIG. 9 , the barrier  22  may extend across the inner periphery of the syringe body  14  above the threads  42  of the mating threads  46  of the distal end portion  30  of the syringe body  14 . To mount the needle assembly  18  to the syringe body  14 , the threads  42  of the needle assembly  18  is threaded onto the mating threads  46 . The needle assembly  18  is threaded into the syringe body  14  until the stop flange  48  contacts the distal end  52  of the syringe body  14 . At or about the same time, a protrusion  60  of the needle assembly  18  may puncture the barrier  22 . By way of example and not limitation, the protrusion  60  may at least slightly tear or weaken the barrier  22  to allow the fluidic medication to enter into or escape out of the variable fluid chamber  26 . The barrier  22  may be characterized as punctured if the barrier  22  is torn or weakened so as to permit fluid to permeate through the barrier  22 . 
     In an aspect of the safety syringe  10 , the syringe  10  may be a sterilized vacuum assisted retractable safety syringe as discussed in U.S. application Ser. No. 11/511,668 (&#39;668 application), filed Aug. 29, 2006, the entire content of which is incorporated herein by reference. The &#39;688 application discusses how fluidic medication is injected into the patient in a sterile manner if the needle assembly is attached to the syringe body. In this regard, the discussion of the &#39;668 application may he employed in the safety syringe  10  with detached needle assembly discussed herein after the detached needle assembly  18  is attached to the syringe body  14 . Additionally, the safety syringe  10  may be a vacuum assisted retractable safety syringe as discussed in U.S. Pat. No. 6,413, 236, filed Jun. 20, 2000 to Van Dyke, the entire content of which is incorporated herein by reference. 
     The safety syringe  10  may have a variable vacuum compartment  62  (see  FIG. 3 ). When the plunger assembly  12  is in the retracted position, the variable vacuum compartment has a pressure equal to ambient pressure. As the plunger assembly  12  is traversed toward the forward position, the variable vacuum compartment  62  increases in volume but additional air molecules are not introduced into the variable vacuum compartment  62 . The reason is that there is a seal between the piston  28  and the inner surface  34  of the syringe body  14  as well as a seal between a shaft  64  and proximal end of the syringe body  14 . One benefit of the vacuum assisted retractable safety syringe  10  is that the inner surface of the variable fluid chamber  26  will not become contaminated by introduction of contaminants via the proximal end of the syringe body  14 . Ambient air does not enter into the variable vacuum compartment  62  through the proximal end of the syringe body  14 . 
     Although the variable vacuum compartment  62  and the variable fluid chamber  26  are separate compartments, during the process of injecting the patient with fluidic medication via the safety syringe  10 , the variable fluid chamber  26  and the variable vacuum compartment  62  share a common surface, namely, the inner surface  34  of the syringe body. For example, the plunger assembly  12  is traversed between two positions, namely, the retracted position and the forward position. When the plunger assembly  12  is in the retracted position, the variable fluid chamber  26  typically has a larger volume compared to the variable vacuum compartment  62 . When the plunger assembly  12  is traversed toward the forward position, the volume of the variable vacuum compartment  62  increases and the volume of the variable fluid chamber  26  decreases because the distal end  28  slides downward against the inner surface  34  of the syringe body  14 . Accordingly, a portion of the inner surface  34  of the syringe body which used to define the variable fluid chamber  26  now at least partially defines the variable vacuum compartment  62 . 
     If ambient air  24  were to enter into the variable vacuum compartment  62  via the proximal end of the syringe body  14 , then contaminants contained in the ambient air  24  may be lodged onto the inner surface  34  of the syringe body. As the plunger assembly  12  is traversed between the retracted position and the forward position, the lodged contaminants on the inner surface  34  of the syringe body may eventually enter into the variable fluid chamber and thereby contaminate any fluidic medication drawn into the variable fluid chamber  26 . 
     A benefit of the vacuum assisted retractable safety syringe is that the variable vacuum compartment  62  remains in a sterile state throughout the entire process of injecting the patient with fluidic medication because ambient air is not allowed into the variable vacuum compartment  62  via the proximal end of the syringe body  14 . 
     Combining the vacuum assisted retractable safety syringe  10  with the barrier  22  provides a complete sterile environment in which the fluidic medication may be withdrawn into the variable fluid chamber  26  and subsequently injected into the patient without concern that the fluidic medication may become contaminated by exposure to the ambient air  24  or to contaminants that may have entered into the variable fluid chamber  26  via the proximal end of the syringe body  14 . 
     In an aspect of the syringe  10 , the detached needle assembly  18  may be attachable to the syringe body  14 , as discussed in U.S. application Ser. No. 11/409,617, filed Apr. 24, 2006, the entire contents of which are expressly incorporated herein by reference. Additionally, the needle  20  of the needle assembly  18  may be retractable into the syringe body  14  as shown in U.S. application Ser. No. 11/409,617. Moreover, the barrier  22  may be attached to the distal end portion  30  of the syringe body  14  shown in  FIGS. 1-5  of U.S. application Ser. No. 11/409,617. 
     The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope and spirit of the invention disclosed herein. Further, the various features of the embodiments disclosed herein can be used alone, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the scope of the claims is not to be limited by the illustrated embodiments.