Ultra-low waste disposable syringe with self-regulating integrated safety features

Abstract

The system (10) has a needle head (12) attached to a syringe assembly (14). The syringe assembly (14) includes a barrel (16) and a plunger (18). The plunger (18) has a bore opening (26) accessible from within the barrel (16). A tubular spacer (40) is disposed within the barrel (16). The tubular spacer (40) defines a central opening (42). The needle head (12) has a needle (30) extending from a needle base (36). The needle base (36) extends into the tubular spacer (40). A plug (28) blocks access to the needle (30). The plug (28) is moved from the tubular spacer (40) into the bore opening (26) of the plunger (18). As the plug (28) is moved, it moves into the bore opening (26) in the plunger (18).

Description

[Technical field]

[0001] TECHNICAL FIELD OF THEINVENTION

[0002] Generally, the present invention relates to syringes used to deliver injections through a needle or cannula. More specifically, the present invention relates to multi-dose syringes designed to minimize the amount of injection material retained within the syringe after the syringe has been used for the final dose. [Background technology]

[0003] Background technology

[0004] Millions of injections are administered each year in the United States. Injections are typically administered using a hypodermic needle and syringe. The length of the hypodermic needle and the dimensions of the needle vary depending on the application and whether the injection is intramuscular, subcutaneous, intravenous, or intradermal. The compounds injected also vary greatly. Some injection materials, such as saline, are very inexpensive. However, many pharmaceutical compounds, such as certain gene therapy compounds, can cost tens of thousands of dollars per injection. Thus, a fraction of a milliliter of a pharmaceutical product can be worth hundreds of dollars.

[0005] When traditional hypodermic needles and syringes are used to administer an injection, a certain volume of injection material inevitably remains inside the needle and syringe after the injection is completed. The remaining medication is discarded along with the needle and syringe after the injection. This wasted medication adds billions of dollars to wasted medication when all injections are considered.

[0006] The prior art inherently gives little consideration to the volume of residual material remaining inside the hypodermic syringe and needle. Some needle and syringe assemblies are designed to provide flush contact between the syringe plunger and the needle head. Such prior art designs are exemplified by U.S. Patent No. 6,616,636 to Lee and U.S. Patent No. 5,902,270 to Jentzen. However, in a real medical environment, such as a hospital, different syringes are used with different needle heads depending on the specific medical application. Some needle head and syringe combinations are effective in expelling pharmaceutical compounds, while others are not.

[0007] The problem becomes even more complicated when the needle head and syringe are part of a safe syringe assembly. A safe syringe assembly is designed to provide a mechanism for performing the injection and minimizing the possibility of needle stick injuries. Needle stick injuries are common among healthcare workers. According to the National Institute for Occupational Safety and Health, a needle stick injury is defined as an injury caused by a needle, such as a hypodermic needle, a blood collection needle, an intravenous (IV) stylet, and a needle used to connect components of an IV delivery system. Needle stick injuries can transmit blood-borne pathogens, such as Hepatitis B virus, Hepatitis C virus, Human Immunodeficiency Virus (HIV), and COVID-19. For healthcare workers, needle stick injuries are responsible for a significant portion of these illnesses among healthcare workers.

[0008] According to the Centers for Disease Control, it is estimated that more than 3 million healthcare workers in the United States are exposed to blood and body fluids each year through needlestick injuries. Most healthcare workers are trained in procedures for using and disposing of used needles. For example, used needles should not be recapped to prevent potential needlestick injuries. However, numerous studies have revealed that recapping remains a widespread practice among healthcare workers.

[0009] To reduce the number of needlestick injuries, various safety needles have been developed that function to automatically cover the needle the moment it is retracted from the skin. This is typically accomplished by advancing a tubular sheath along the shaft of the needle until the sheath covers the tip of the needle. Such prior art is exemplified by U.S. Pat. No. 6,626,863, U.S. Patent Application Publication No. 2007 / 0016140, U.S. Patent Application Publication No. 2007 / 0016145, and U.S. Patent Application Publication No. 2008 / 0009808. However, integrating a safety mechanism within the needle head typically requires additional space within the needle head. More space in the needle head means more dead space in which residual pharmaceutical compounds can collect in the needle head. As a result, there are often opposing concerns that must be balanced in the design. The safety features of the design are balanced against the wasted pharmaceutical that is retained because of the safety features. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] U.S. Patent No. 6,616,636 [Patent Document 2] U.S. Patent No. 5,902,270 [Patent Document 3] U.S. Patent No. 6,626,863 [Patent Document 4] US Patent Application Publication No. 2007 / 0016140 [Patent Document 5] US Patent Application Publication No. 2007 / 0016145 [Patent Document 6] US Patent Application Publication No. 2008 / 0009808 Summary of the Invention [Problem to be solved by the invention]

[0011] Thus, there is a need for an improved hypodermic needle and syringe assembly in which the needle automatically shields after injection and in which the assembly does not retain a large volume of injected material. These needs are met by the present invention as described and claimed below. [Means for solving the problem]

[0012] Disclosure of the Invention

[0013] The present invention is a needle and syringe system, in which a needle head is attached to a syringe assembly including a barrel and a plunger, the plunger having a bore opening formed in one end accessible from within the barrel.

[0014] A tubular spacer is disposed within the barrel. The tubular spacer defines a central opening extending therethrough.

[0015] A needle head is selectively attached to the syringe assembly. The needle head has a needle extending from a needle base. The needle base extends into the central opening of the tubular spacer.

[0016] A plug is provided inside the barrel that blocks access to the needle by blocking a central opening in the tubular spacer. When the plunger contacts the tubular spacer in the barrel to move the tubular spacer within the barrel, the plug moves from the central opening in the tubular spacer into the opening in the plunger. As the plug moves out of the tubular spacer, it transitions into a bore opening in the plunger, which allows the plunger to push the flush against the tubular spacer.

[0017] As the tubular spacer is moved by the plunger, it advances the needle and moves a safety sheath which covers it and secures the needle therein. [Brief description of the drawings]

[0018] BRIEF DESCRIPTION OF THE DRAWINGS

[0019] For a better understanding of the present invention, reference is made to the following description of illustrative embodiments thereof, taken in conjunction with the accompanying drawings, in which: [Figure 1] The head of the needle and syringe system is shown with the needle exposed and ready for use. [Diagram 2] FIG. 2 is a cross-sectional view of the exemplary embodiment of FIG. [Diagram 3] FIG. 2 is an exploded cross-sectional view of the exemplary embodiment of FIG. 1. [Figure 4] FIG. 13 is a cross-sectional view of the head sub-assembly prior to attachment to the syringe sub-assembly. [Diagram 5] 2 is a cross-sectional view of the exemplary embodiment of FIG. 1 showing material being drawn into the needle and syringe system. [Figure 6] 2 illustrates a cross-section of the exemplary embodiment of FIG. 1 showing material being transferred from a needle and syringe system. [Figure 7] 2 illustrates a cross-section of the exemplary embodiment of FIG. 1 showing all material transferred from the needle and syringe system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Detailed Description of the Best Mode for Carrying Out the Invention

[0021] The needle and syringe system of the present invention can be configured in a variety of ways and adapted for use in many applications. However, for purposes of description and illustration, only one exemplary embodiment has been selected. However, the described embodiment is merely exemplary and should not be considered as a limitation when interpreting the appended claims.

[0022] 1, 2 and 3, a needle and syringe system 10 of the present invention is shown. In the embodiment shown, the needle and syringe system 10 includes two main subassemblies that are selectively coupled by a medical professional prior to use. The main subassemblies include a head subassembly 12 and a syringe subassembly 14. The head subassembly 12 mechanically engages the syringe subassembly 14 using a mechanical connection, as will be described below. Thus, different head subassemblies can be selectively attached to different syringe subassemblies depending on the needs of the medical professional.

[0023] Syringe subassembly 14 includes a syringe barrel 16 and a plunger rod 18 that extends into the syringe barrel 16. Plunger rod 18 has a first end 20 and an opposite second end 21. First end 20 extends into the syringe barrel 16. Second end 21 terminates in a thumb pad 22 that is used to manually move plunger rod 18 within syringe barrel 16 between a first fully advanced position and a second fully retracted position. First end 20 of plunger rod 18 terminates in an elastomeric piston head 24. Piston head 24 is annular in shape and seals plunger rod 18 within the syringe barrel 16.

[0024] A blind bore 26 is formed in plunger rod 18, with blind bore 26 opening at first end 20 of plunger rod 18. The annular shape of piston head 24 prevents piston head 24 from blocking access to blind bore 26 from within syringe barrel 16. Blind bore 26 extends a first length into plunger rod 18.

[0025] An elongated plug 28 is provided. The elongated plug 28 has the same length as the blind bore 26 in the plunger rod 18 and can be fully received within the blind bore 26 of the plunger rod 18. The elongated plug 28 travels between the head subassembly 12 and the syringe subassembly 14, however the elongated plug 28 is initially packaged as part of the head subassembly 12, as will be described below. The head subassembly 12 holds a needle 30. The needle 30 extends forwardly from a plastic needle base 32. The needle base 32 includes a collar 34 sized and shaped to engage with the syringe subassembly 14. The collar 34 engages the syringe barrel 16 using a mechanical connection, such as a threaded or bayonet connection. This allows the medical professional to manually connect and disconnect the head subassembly 12 and the syringe subassembly 14. A central post 36 is concentrically disposed within the collar 34. A cylindrical cavity 38 separates collar 34 from central post 36. Needle 30 extends through and into central post 36. Because needle 30 is attached to central post 36, which is attached to collar 34, and collar 34 is attached to syringe barrel 16, there is no relative movement between needle 30 and syringe barrel 16 during operation of needle and syringe system 10.

[0026] A tubular spacer 40 is provided as part of the head subassembly 12. The tubular spacer 40 is positioned within a cylindrical cavity 38 between the central post 36 and the collar 34. The tubular spacer 40 defines a central conduit 42 that receives the central post 36 of the needle base 32. The length of the cylindrical cavity 38 in the tubular spacer 40 is exactly the same as the length of the central post 36. The tubular spacer 40 is separate from the needle base 32 and is free to slide along the length of the central post 36.

[0027] A safety sheath 44 is provided which surrounds a portion of the needle 30. The safety sheath 44 is attached to an actuator cap 46. The actuator cap 46 is sized to extend over the exterior of the needle base 32. The actuator cap 46 is reciprocally movable along the exterior of the needle base 32. The actuator cap 46 is selectively lockable and unlockable using a mechanical release 48 accessible exterior to the syringe subassembly 14. It will thus be appreciated that the actuator cap 46 can be selectively released and moved relative to the needle 30 and the needle base 32.

[0028] 4 in conjunction with FIGS. 2 and 3, it can be seen that the elongated plug 28 is part of the head subassembly 12 prior to use. The elongated plug 28 is centrally positioned within the conduit 42 of the tubular spacer 40. When the head subassembly 12 and the syringe subassembly 14 are interconnected, it blocks the needle 30 and isolates the needle 30 within the head subassembly 12. Once the head subassembly 12 is attached to the syringe barrel 16, loading of the needle and syringe system 10 can begin. To load the needle and syringe system 10, the plunger rod 18 is advanced into the syringe barrel 16. As the first end 20 of the plunger rod 18 moves towards the head subassembly 12, the first end 20 contacts the elongated plug 28. The elongated plug 28 enters a blind bore 26 in the plunger rod 18. The blind bore 26 receives and retains the elongated plug 28 with an interference fit.

[0029] 5 in conjunction with FIG 4, it can be seen that after elongated plug 28 is received within blind bore 26, plunger rod 18 is retracted. Plunger rod 18 retains elongated plug 28 and withdraws elongated plug 28 from tubular spacer 40. This clears needle 30 and allows fluid to be drawn into syringe barrel 16 through needle 30.

[0030] 6 and 7, it can be seen that after needle and syringe assembly 10 is filled, plunger rod 18 is manually advanced into syringe barrel 16. Liquid previously drawn into syringe barrel 16 is displaced through needle 30. As piston head 24 advances toward head subassembly 12, it forces tubular spacer 40 into cylindrical cavity 38 around central post 36 of needle base 32. At the same time, elongated plug 28 is forced into blind hole 26 in plunger rod 18. When piston head 24 contacts central post 36, tubular spacer 40 completely fills cylindrical cavity 38. All liquid is displaced from syringe barrel 16 except for a very small volume that remains inside needle 30.

[0031] As tubular spacer 40 is pushed forward by advancing plunger rod 18, tubular spacer 40 moves actuator cap 46 forward relative to needle base 32. As actuator cap 46 moves forward, safety sheath 44 also moves forward, and safety sheath 44 covers the tip of needle 30. As a result, needle 30 is shielded and rendered harmless just as syringe barrel 16 is emptied.

[0032] It will be understood that the illustrated and described embodiments of the invention are merely exemplary and that many variations therein may be made by one skilled in the art, and all such embodiments are intended to be within the scope of the invention as defined by the appended claims.

Claims

1. 1. A needle and syringe system comprising: a syringe barrel having an interior; a plunger rod having a first end and an opposite second end, said plunger rod having a bore formed therein accessible from said first end, said bore extending a first length into said plunger rod from said first end, said plunger rod being reciprocally movable between a first position and a second position within said syringe barrel; a needle head attached to the syringe barrel, the needle head having a needle extending through a central post of a needle base, the first end of the plunger rod facing the needle head within the syringe barrel; a tubular spacer defining a central conduit, the central post of the needle base and the central conduit of the tubular spacer having equal lengths, the first end of the plunger rod being closest to the tubular spacer when in the first position within the syringe barrel and being farther from the tubular spacer when in the second position within the syringe barrel; a plug having a length at least as long as the first length of the hole, the plug being separate and distinct from the needle base, the plunger rod, and the tubular spacer, the plug being initially disposed within the central conduit of the tubular spacer, the plug moving out of the central conduit and into the hole of the plunger rod as the plunger rod is moved for a first time between the first position and the second position, when the plug is present within the central conduit of the tubular spacer, the plug completely blocks the central conduit of the tubular spacer and isolates the needle from the interior of the syringe barrel, and when the plug is fully received within the hole, the plug completely fills the hole.

2. 10. The system of claim 1, wherein the needle head further includes a collar for selectively connecting to the syringe barrel, the collar supporting a needle base that extends into the central conduit of the tubular spacer.

3. The system of claim 1 , wherein the needle head further includes a safety sheath surrounding a portion of the needle, the safety sheath being movable relative to the needle to selectively shield the needle.

4. The system of claim 3 , wherein the plunger rod contacts and advances the spacer when the plunger rod moves from the first position to the second position.

5. The system of claim 4 , wherein the needle base moves through the central conduit within the spacer when the spacer is advanced by the plunger rod.

6. The system of claim 5 , wherein the needle base displaces the plug from the needle head as the needle base moves through the central conduit in the spacer.

7. 1. A needle and syringe system comprising: a syringe assembly including a barrel and a plunger, the barrel having an interior, the plunger having an opening formed therein and accessible from within the barrel, the opening extending a first length into the plunger; a tubular spacer disposed in the barrel, the tubular spacer having a central opening extending therethrough; a needle head selectively attached to said syringe assembly, said needle head having a needle extending from a needle base, said needle base extending into said central opening of said tubular spacer, said needle base and said central opening of said tubular spacer having equal lengths; 1. A needle and syringe system comprising a plug separate and distinct from the needle head, the plunger, and the tubular spacer, the plug being initially positioned within the central opening of the tubular spacer, the plug blocking the central opening of the tubular spacer, the plug moving from the central opening of the tubular spacer into the opening of the plunger a first time the plunger moves the tubular spacer within the barrel, and when the plug is fully received within the opening, the plug completely fills the opening.

8. The system of claim 7 , wherein the opening in the plunger is sized to receive all of the plug therein.

9. The system of claim 7 , wherein the needle head further includes a safety sheath surrounding a portion of the needle, the safety sheath being movable relative to the needle.

10. The system of claim 7 , wherein the plunger contacts and advances the tubular spacer as the plunger moves within the barrel toward the needle.

11. The system of claim 10 , wherein the needle base moves through the central opening in the tubular spacer when the tubular spacer is advanced by the plunger.

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