Safety syringe assembly

Abstract

Safety syringe assemblies are described. A safety syringe assembly comprises a syringe barrel, a needle hub having a proximal end configured to be connected to the syringe tip and a distal end having an opening configured to receive a needle cannula, a needle plug comprising a distal end comprising a socket and a proximal end comprising a plunger connection element configured to engage a needle plug engagement element on the distal face of the plunger rod. The needle plug and the needle cannula are retractable inside the syringe tip or the needle hub.

Description

P-30479.W001 PATENT1SAFETY SYRINGE ASSEMBLYTECHNICAL FIELD

[0001] Embodiments of the present disclosure generally relate to syringes and needle assemblies. Specific embodiments of the disclosure relate to syringe assemblies that include a needle that is retractable after the intended use to substantially prevent inadvertent exposure to the needle and reuse of the syringe assembly.BACKGROUND

[0002] Hypodermic syringe assemblies are widely used for administering medicaments to patients and for drawing body fluid samples from patients. Generally, hypodermic syringe assemblies include a fixedly or removably attached metal needle that has a sharpened distal point for penetrating vial stoppers or a patient's skin. Some hypodermic syringe assemblies include provisions to prevent reuse to protect health care workers from inadvertent contact with previously used needles as well as the need to reduce misuse of improperly disposed of needles and syringes.

[0003] For example, some syringe assemblies include needle attachments that can be readily broken off by practitioners after intended use of the syringe assembly. Also, a variety of shielding mechanisms have been developed, which are intended to shield the needle cannula after it has been used, thus reducing the risk of an accidental needle stick. Further developments in hypodermic syringe assemblies have provided syringe assemblies with needles that withdraw into the body of the syringe barrel once their intended use is completed. These are often referred to as retracting needle syringes. Many such devices include complicated costly components, for example, a metallic stopper cutter, spring, a plunger rod, and a separate stopper made from a material such as natural rubber, or thermoplastic elasotomers that is softer than the plunger rod. Once trapped inside the plunger and body of the syringe, the needle is no longer subject to accidental contact with human tissue to prevent pricking, poking and / or wounding a practitioner with the distal point of the needle cannula.P-30479.W001 PATENT2

[0004] While existing safety syringe assemblies serve their intended purpose, there is always room for improvement of existing devices with by providing devices with improved functionality or fewer components.SUMMARY

[0005] One aspect of the present disclosure pertains to a safety syringe assembly comprising a syringe barrel comprising a barrel wall having an internal surface defining a chamber configured to contain a fluid, the barrel wall extending to a distal wall, the syringe barrel including an open proximal end configured to receive a plunger rod, a syringe tip extending from the distal wall and having a distal tip fluid volume; the plunger rod including a proximal end having a thumb press and a distal end comprising a distal face including a peripheral surface having an integral peripheral seal that forms a seal against the internal surface of the barrel wall; and a needle assembly including a needle hub having a proximal end configured to be connected to the syringe tip and a distal end having an opening configured to receive a needle cannula, a needle plug comprising a distal end comprising a socket and a proximal end comprising a plunger connection element configured to engage a needle plug engagement element on the distal face of the plunger rod, the needle cannula having a proximal end slidably engaged within the opening in the needle hub and fitted into the socket, the needle cannula further including distal end, the needle plug slidably removable from one or more of syringe tip and the needle hub to allow the distal tip of the needle cannula to be withdrawn into at least one of the distal end of the needle hub and the distal tip of the syringe.

[0006] Some embodiments of the present invention include a reuse prevention feature, for example, a hollow plunger rod to allow the needle cannula to retract into the plunger rod after use. In some embodiments, the distal end of the needle cannula is configured to retract within the distal end of the needle hub. In some embodiments, the distal end of the needle cannula is configured to retract within the distal tip extending from the syringe barrel.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure,P-30479.W001 PATENT3 briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.

[0008] FIG. 1 illustrates a cross-sectional view of syringe assembly according to an embodiment including a needle plug inserted in a needle hub in a pre-injection position;

[0009] FIG. 2A illustrates an enlarged view of a portion of the syringe assembly shown in FIG. 1 in a pre-injection position before the plunger rod and a needle plug are engaged;

[0010] FIG. 2B is an enlarged view of a portion of the syringe assembly shown in FIG. 2A still in a post-injection position with the plunger rod and the needle plug engaged so that the needle plug and needle cannula can be retracted within the syringe tip or needle hub;

[0011] FIG. 3 illustrates an alternate embodiment of a syringe assembly showing a portion of the syringe assembly with the in a post-injection position with the plunger rod and the needle plug engaged so that the needle plug and needle cannula can be retracted within the syringe tip or needle hub;

[0012] FIG. 4 illustrates the embodiment shown in FIG. 1 , illustrating the plunger rod in a retracted position and the distal end of the needle cannula retracted within the syringe tip;

[0013] FIG. 5A illustrates assembly of a syringe assembly showing insertion of a needle plug to a syringe tip according to one or more embodiments;

[0014] FIG. 5B illustrates assembly of a syringe assembly showing attachment of the needle hub to the syringe tip by a Luer lock fitting;

[0015] FIG. 5C illustrates assembly of a syringe assembly showing insertion of the needle cannula to the needle hub;

[0016] FIG. 5D illustrates assembly of a syringe assembly showing the needle cannula inserted into the needle plug and a plunger rod inserted in the syringe barrel;

[0017] FIG 6A illustrates a prior art needle assembly;

[0018] FIG. 6B illustrates a needle assembly according to one or more embodiments, showing reduction of dead space in the syringe tip;P-30479.W001 PATENT4

[0019] FIG. 7A illustrates a needle assembly according to one or more embodiments, including a filtration device;

[0020] FIG. 7B illustrates use of the needle assembly shown in FIG. 7A;

[0021] FIG. 8 illustrates a needle assembly according to one or more embodiments including a reuse prevention feature;

[0022] FIG. 9 illustrates a needle assembly according to one or more embodiments including another reuse prevention feature;

[0023] FIG. 10A illustrates a needle assembly according to one or more embodiments including a hollow plunger rod which provides a reuse prevention feature; and

[0024] FIG. 10B illustrates the needle assembly shown in FIG. 10A with the needle cannula within the hollow plunger rod.DETAILED DESCRIPTION

[0025] In this disclosure, a convention is followed wherein the distal end of the device is the end closest to a patient, e.g., for delivery of one or more drugs to the patient, and the proximal end of the device is the end away from the patient and closest to a clinician or other medical practitioner. With respect to terms used in this disclosure, the following definitions are provided.

[0026] As used herein, the use of "a," "an," and "the" includes the singular and plural.

[0027] As used herein, the term "Luer connector" refers to a connection collar that is the standard way of attaching syringes, catheters, hubbed needles, I.V. tubes, etc. to each other. The Luer connector consists of male and female interlocking tubes, slightly tapered to hold together better with even just a simple pressure / twist fit. Luer connectors can optionally include an additional outer rim of threading, allowing them to be more secure. The Luer connector male end is associated with a syringe discharge tip and can interlock and connect to the female end that is incorporated within a proximal end of a needle hub of a drug dispensing needle or filling needle for aspirating a drug from a drug vial into a syringe. Luer connector female ends are commonly located on vascular access devices (VADs).

[0028] As used herein, ISO 80369-7:2016 defines a specification for standard Luer connectors including a 6% taper between the distal end and the proximal end. A maleP-30479.W001 PATENT5 standard Luer connector increases from the open distal end to the proximal end. A female standard Luer connector decreases from the open proximal end to the distal end. According to ISO 80369-7:2016, a male standard Luer connector has an outer cross-sectional diameter measured 0.75 mm from the distal end of the tip of between 3.970 mm and 4.072 mm. The length of the male standard Luer taper is between 7.500 mm to 10.500 mm. The outer cross-sectional diameter measured 7.500 mm from the distal end of the tip is between 4.376 mm and 4.476 mm. As used herein, the phrases "male standard Luer connector" and "female standard Luer connector" shall refer to connectors having the dimensions described in ISO 80369-7, which is hereby incorporated by reference in its entirety.

[0029] As would be readily appreciated by skilled artisans in the relevant art, while descriptive terms such as "tip", "hub", "thread", "protrusion / insert", "tab", "wall", "top", "side", "bottom" and others are used throughout this specification to facilitate understanding, it is not intended to limit any components that can be used in combinations or individually or to require specific spatial orientations, to implement various aspects of the embodiments of the present disclosure.

[0030] According to one or more embodiments, when an element or structure is referred to as being "configured to" perform a particular function, or "made to" or "designed to" perform that function, however, when the disclosure makes clear that the recited structure is "designed to" or "constructed to" perform that function, the element or structure is designed, made or configured to accomplish the specific objective.

[0031] Before describing several exemplary embodiments of the disclosure, it is to be understood that the disclosure is not limited to the details of construction or process steps set forth in the following description. The disclosure is capable of other embodiments and of being practiced or being carried out in various ways.

[0032] Different embodiments of the present disclosure provide one or more benefits. In one embodiment, a simplified, low-cost safety syringe assembly is provided. The features described eliminate the need for complicated costly components and their assembly as in current syringe designs such as a metallic cutter, a spring, a hollow plunger rod, and specialized stoppers made from separate materials from the plunger rod. Some embodiments include a hollow plunger rod.P-30479.W001 PATENT6

[0033] In one or more embodiments, the syringe assembly provides a reduced dead volume. As used herein "dead volume" refers to a volume inside the syringe barrel and syringe that contains fluid that is not expels by the distal part of the syringe. Some embodiments minimize syringe dead volume at the syringe tip and eliminate needle hub dead volume. Some embodiments provide an integrated safety syringe assembly which utilizes the syringe barrel as a waste container for the needle after injection. Thus, in such embodiments, the volume of waste from used syringe assemblies is reduced because more safety syringes can be placed in a given waste container volume due to a lower safety syringe assembly footprint after safety feature activation. A breakable plunger rod design would further increase the number of safety device that can fit into the medical waste container.

[0034] Some embodiments provide a two-piece syringe concept, which leverages a two-piece syringe design for enhanced functionality and no need for a separate stopper, which would be considered an additional piece of a three-piece syringe. This also leads to reduced cost of the overall syringe assembly by eliminating the stopper and the associated lubrication material and manufacturing step. Some embodiments provide a simplified needle hub design streamlines the needle hub and eliminates the need for undercuts at the tip of the hub.

[0035] Referring now to FIGS. 1 , 2A and 2B, FIG. 1 illustrates a cross-sectional view of syringe assembly 100 according to one more embodiments including a needle plug 150 inserted in a needle hub 130 in a pre-injection position, prior to using the syringe for injecting contents of the syringe into a patient.

[0036] As shown, the syringe assembly includes a syringe barrel 102 comprising a barrel wall 103 having an internal surface 103a defining a chamber 101 configured to contain a fluid. The barrel wall 103 extends from a proximal end 103p to a distal wall 103d, and the syringe barrel 102 includes an open proximal end 102p configured to receive a plunger rod 110, and a syringe tip 106 extending from the distal wall 103d and having a distal tip fluid volume.

[0037] The plunger rod 1 10 includes a proximal end having a thumb press 109 and a distal end 1 10d comprising a distal face 112 including a peripheral surface 1 12p having an integral peripheral seal that forms a seal against the internal surface 103a of the barrel wall 103. As used herein, an integral peripheral seal refers to a seal thatP-30479.W001 PATENT7 is formed as a unit with the peripheral surface 1 12p of the distal face of the plunger rod, which is distinguished from a plunger rod that has a separate stopper or seal that is mounted to the distal end of the plunger rod.

[0038] The needle assembly includes a needle hub having 130 a proximal end 130p configured to be connected to the syringe tip 106 and a distal end 130d having an opening 132 configured to receive a needle cannula 104. The needle assembly further comprises the needle plug 150 comprising a distal end 150d comprising a socket 151 and a proximal end comprising a needle plug engagement element 152 configured to engage a plunger connection element 122 on the distal face 112 of the plunger rod 110.

[0039] The needle cannula 104 has a proximal end 104p slidably engaged within the opening 132 in the needle hub and fitted into the socket 151 , and the needle cannula 104 further includes a distal end 104d. The needle plug 150 is slidably removable from one or more of syringe tip 106 and the needle hub 130 to allow the distal end 104d of the needle cannula 104 to be withdrawn into at least one of the distal end 130d of the needle hub 130 and the distal tip of the syringe assembly 100.

[0040] FIG. 2A illustrates an enlarged view of a portion of the syringe assembly 100 shown in FIG. 1 in the pre-injection position before the plunger rod 110 and a needle plug are engaged. In the embodiment shown, there is a collar 154 surrounding the syringe tip 106. In one or more embodiments, the collar 154 includes female threads 155 configured to be threadably engaged with external male lugs or external male ears 135 on the proximal end 130p of the needle hub. The female threads 155 and the external male lugs or external male ears 135 together provide a Luer lock fitting, which is a standardized, secure connection system used in medical settings to attach needles, syringes, catheters, intravenous lines, and other tubing without leakage, even under pressure. Thus, a male Luer lock fitting has the external male lugs or external male ears 135 that threadably engage a female Luer lock having internal threads or female threads 155 as shown.

[0041] FIG. 2B is an enlarged view of a portion of the syringe assembly shown in FIG. 2A still in a post-injection position with the plunger rod 1 10 and the needle plug engaged so that the needle plug 150 and needle cannula 104 can be retracted within the syringe tip 106 or the distal end 130d of the needle hub 130. The needle plug 150P-30479.W001 PATENT8 is slidably removable from the syringe tip 106 of the syringe barrel as will be described further below. As can be seen in FIG. 2A, the distal end 150d of the needle plug 150 provides a contact surface and the needle hub 130 includes a shoulder 137 providing a stopping surface that engages the contact surface on the distal end 150d of the needle plug 150 to prevent the needle plug 150 from being forced through the syringe tip 106.

[0042] Referring now to FIG. 3, an alternate embodiment of a syringe assembly is shown as illustrating a portion of the syringe assembly 100 in a post-injection position with a different type of plunger rod 210 having a distal end 21 Od and a peripheral seal 212 comprising a flexible finger extending from the plunger rod 210. In the embodiment shown in FIG. 3, instead of a Luer lock connection between the needle hub 130 and the syringe tip 106, the needle hub 130 has an internal surface 130a comprising a Luer slip fitting and the syringe tip 106 comprises a Luer slip fitting configured to slidably receive the needle hub. FIG. 3 also shows the needle plug 150 engaged with the plunger rod 110 so that the needle plug 150 and needle cannula 104 can be retracted within the syringe tip 106 or the distal end 130d of the needle hub130. In the embodiment shown in FIG. 3, the distal end 150d of the needle plug 150 provides a contact surface, and the needle hub 130 includes a shoulder 107 providing a stopping surface that engages the contact surface at the distal end 150d of the of the needle plug to 150 prevent the needle plug from being forced through the syringe tip 106.

[0043] FIG. 4 illustrates the embodiment of the syringe assembly 100 shown in FIG. 1 , illustrating the plunger rod in a retracted position and the distal end 104d of the needle cannula 104 retracted within the syringe tip 106. The plunger connection element 122 comprises a stem 122s extending to an enlarged head 122d configured to engage the needle plug engagement element 152 comprising a receptacle. The needle plug engagement element 152 comprises a receptacle sized and shaped to receive the enlarged head 122d at the end of stem 122s of the plunger connection element 122 that extends distally from the distal face 1 12 of the plunger rod.

[0044] In one or more embodiments, the needle plug 150 is sized and shaped so that the needle plug 150 fills at least 80% of the syringe tip 106 fluid volume prior to removal of the needle plug 150 from the syringe tip 106. In some embodiments, the needle plug 150 is sized and shaped so that it fills at least 90% or 95% of the syringe tip fluid volumeP-30479.W001 PATENT9 prior to removal of the needle plug 150 from the syringe tip 106. In some embodiments, the needle plug 150 is sized and shaped so that it fills at least 99% of the syringe tip fluid volume prior to removal of the needle plug 150 from the syringe tip 106.

[0045] Referring now to FIG 6A and FIG. 6B, the two FIGS taken together illustrate the needle plug filling at least 80%, 90%, 95%, or 99% of the syringe tip fluid volume. FIG. 6A illustrates a prior art needle assembly 400 including a needle cannula, 404, a syringe barrel comprising a barrel wall 403 a plunger rod 410 having a distal end 41 Od, and the syringe barrel including a syringe tip 406 defining a fluid volume. A needle hub 430 holds the needle cannula 404. When the distal end 41 Od of the plunger rod 410 is at the furthest distal position in the chamber 401 of the syringe barrel, there is dead volume 406d (or dead space) in the syringe tip 406, which contains a volume of unused liquid. FIG. 6B illustrates a needle assembly according to one or more embodiments, showing a significant reduction of dead volume in the syringe tip 106, as the needle plug 150 fills the volume of the syringe tip 106.

[0046] Referring now to FIGS. 5A-D, which show an example a method of assembling of the syringe assembly 100 according to one or more embodiments. The steps can be performed in a different order than those shown. First, as shown in in FIG. 5A, the needle plug 150 is inserted into the syringe tip by press-fitting the needle plug 150 into the syringe tip. FIG. 5B illustrates attachment of the needle hub 130 to syringe tip 106 by a Luer lock fitting as shown herein. The needle hub 130 may also be assembled by a Luer slip fitting as described herein. FIG. 5C illustrates insertion of the needle cannula 104 to the needle hub 130. It will be understood that the steps in FIG. 5B and 50 could be reversed, and the needle cannula 104 may be inserted into the needle hub 130 prior to the needle hub 130 being assembled to the syringe tip 106. Optionally, an adhesive may be applied to the needle plug 150 or to the proximal end 104p of the needle cannula 104 to provide further securement force or holding force of the needle cannula 104 to the needle plug 150. In FIG. 5D, the plunger rod 110 is inserted in the syringe barrel 102. The needle plug 150 is slidably removable from the syringe tip 106 of the syringe barrel 102 to allow the needle plug 150 to move in a proximal direction so that the distal end 104d of the needle cannula 104 can be withdrawn inside the syringe tip 106 and to prevent contact with the distal end 104d of the needle cannula 104. The proximal end 104p of the needle cannula 104 is heldP-30479.W001 PATENT10 within the socket 151 of the needle plug 150 by a friction interference fit to provide a holding force sufficient to slidably move the distal tip of the needle cannula into the syringe tip. In some embodiments, an adhesive provides additional holding force of the needle cannula 104 in the needle plug 150.

[0047] In some embodiments, the needle plug 150 dimensions are designed in such a way that there is a Plug Removal Force F2 that is much higher than skin penetration force F1 with a predetermined safety factor selected to account for the worst-case dimension. A press fit interference design (plastic to plastic design) between the needle plug 150 and the syringe tip 106 create contact pressures on the order of 200 psi, which is higher than pressure generated by syringe plunger during injection of medication, which aids in assisting seal performance.

[0048] The plunger rod 1 10 is inserted so that there is a space between the needle plug engagement element 152 and the plunger connection element 122 on the distal face 112 of the plunger rod 1 10. The syringe assembly 100 is ready for use and can be packaged for use. In some embodiments, the plunger rod 110 may be breakable into two or more pieces after use to reduce the volume of medical waste after use of the syringe assembly 100.

[0049] Referring now to FIG. 7A a syringe assembly 100 is shown as described herein as further comprising a tubular adapter 190 comprising a proximal end 190p and a distal end 190d, the tubular adapter 190 configured to cover the distal end 104d of the needle cannula 104 and further comprising a filter element 192 configured to filter particles from a liquid medium on the distal end 190d of the tubular adapter 190. The proximal end 190p of the tubular adapter 190 is configured to engage and fit over the needle hub 130.

[0050] The embodiment shown may further comprise a tubular cover 195 is configured to envelope the tubular adapter 190. The tubular cover 195 is removably attached to the syringe assembly 100. In some embodiments, the shield 200 is transparent. The tubular cover 195 provides protection from foreign material entering the filter element192 prior to its use. In the embodiments shown, the proximal end of the tubular cover 195 is slidably engaged with the tubular adapter 190 to secure the tubular cover 195 to the syringe assembly 100.P-30479.W001 PATENT1 1

[0051] According to one or more embodiments, a "filter element" refers to a porous element configured to filter particles from a liquid medium. In one or more embodiments, the filter element is constructed of porous polymers, such as an elastomer having a Shore D hardness in a range of 30-70. In one or more embodiments, the filter element 192 is optimized and configured to filter particles, in particular, glass particles that have a size greater than 5 pm from a liquid medium. In some embodiments, the filter element 192 is fabricated by blowing out air or blowing agent during injection or hot press molding (such as microcellular injection molding). In other embodiments, the filter element 192 is fabricated by preferential solubilization or precipitation of mixed particles, such as salt. In yet other embodiments, the filter element 192 is fabricated by thermal, laser or ultrasonic welding or sintering of polymeric material. Exemplary polymeric materials include but are not limited to polypropylene, polyethylene, polystyrene, polytetrafluoroethylene (PTFE), acrylic, polyethersulfone, Nylon, Cellulose Nitrate.

[0052] The syringe assembly 100 is configured so that a syringe attached to the tubular adapter 190 is configured to aspirate medication from a glass ampoule 198 shown in FIG. 7B and injected into an IV bag (not shown). In one or more embodiments, the tubular adapter 190 comprises plastic material. In some embodiments, the plastic material comprises polypropylene, polyethylene, polycarbonate, or any other suitable plastic material used in the art of medical devices. In one or more embodiments, the tubular adapter 190 fully or partially comprises elastomeric material. In some embodiments, the elastomeric material comprises thermoplastic elastomer (TPE). In some embodiments, the tubular adapter 190 is transparent.

[0053] In some embodiments, the filter element 192 is assembled inside the distal end 190d of the tubular adapter 190. In some embodiments the filter element 192 is sealed inside the distal end 190d of the tubular adapter 190 by a sealing method, for example, insert molding, adhesive bonding, ultrasonic welding, or by any other suitable sealing method. In this way, the filter element 192 is integrated with the syringe assembly 100. In some embodiments, the filter element 192 has a porosity configured to filter glass particles or glass shards that are present inside a glass ampoule.P-30479.W001 PATENT12

[0054] Referring now to FIG. 7B, use of the syringe assembly 100 shown in FIG. 7A is shown. As shown in FIG. 7B, the distal end 190d of the tubular adapter 190 is inserted into the ampoule 198, and the medication is aspirated through the tubular adapter 190 of the syringe assembly 100 into the syringe attached to the tubular adapter 190. In some embodiments, after aspiration of the medication to the syringe, the syringe assembly 100 with the syringe attached is removed from the ampoule 198, and the tubular adapter 190 is detached.

[0055] One of more embodiments of the syringe assembly described herein further comprises a reuse prevention feature. Reuse prevention features are designed to prevent a syringe assembly from being used more than once. Referring now to FIG. 8, according to one or more embodiments of the syringe assembly 100 described herein, the internal surface 103a of the barrel wall including an undercut 103c adjacent to the proximal end 103p of syringe assembly 100. The undercut 103c can be in the form of a cut opening, a dimple or depression that is configured to receive the peripheral surface 112 of the plunger rod 1 10 to lock the plunger rod 110 to prevent further movement of the plunger rod 1 10 and to prevent reuse of the syringe assembly 100. The undercut 103c interacts with the peripheral surface 1 12 of the plunger rod which is shown in the form of a finger deflecting against the internal surface 103a, effectively creating a mechanical stop. The undercut 103c feature can provide a clear tactile feedback when the plunger is moved in the further proximal position, and once locked, the plunger rod 110 be pushed forward in the distal direction, which prevents reuse of the syringe assembly 100.

[0056] In some embodiments, when the reuse prevention features is activated, the needle cannula 104 remains engaged with the plunger rod 1 10, moving back and forth continuously. If the user attempts to aspirate medication using the same needle cannula 104, the needle cannula 1014 will retract with the plunger rod during aspiration inside barrel and consequently, alarm the user that needle cannula cannot be used for injection. In some embodiments, when the needle plug 150 is removed from the syringe tip 106, the distal end 150d of the needle plug is configured to flare out. This deformation at the distal end 150d of the needle plug requires a significant amount of force to return the plug to its original position, preventing reuse.P-30479.W001 PATENT13

[0057] FIG. 10A illustrates a syringe assembly 100 according to one or more embodiments including a hollow plunger rod which provides a different type or additional type of a reuse prevention feature. In the embodiments shown, the plunger rod 1 10 includes a hollow cavity 1 11 configured to receive the needle plug 150 and the needle cannula one the syringe assembly 100 has been used. FIG. 10B illustrates the needle assembly shown in FIG. 10A with the needle cannula 104 within the cavity 1 1 1 of the hollow plunger rod 1 10. According to the embodiment shown in FIGS. 10A and 1 B, a cavity 1 11 for the needle cannula 104 and the needle plug 150 is formed in the hollow plunger rod. The mechanism is configured to operate as soon as the plunger rod 1 10 engages with the needle plug 150, and the force of engagement buckles an overmolded silicone piece at the distal end 1 10d of the at the plunger rod 1 10, allowing the needle cannula 1014 to automatically engage with the cavity 1 1 1 inside the plunger rod 1 10. In the embodiment shown, an additional feature may be provided in the form of a spring (not shown) that can be located between the distal end 150d of the needle plug 150 and the syringe tip 106.

[0058] Other reuse prevention features may be used in combination with those described immediately above, or they may be used separately. Referring now to FIG. 9, a safety syringe assembly 100 is shown, where the needle cannula 104 and the needle plug 150 are configured so that when the needle plug 150 and the needle cannula 104 are retracted within the chamber 101 , the distal end 104d of the needle cannula 104 becomes misaligned with the syringe tip 106 to further prevent reuse of the syringe assembly. As shown in FIG. 9, when the needle cannula 104 is properly aligned with the syringe tip 106 and extends through the syringe tip 106 the needle cannula 104 is parallel to the axis 99 shown as a dotted line in FIG. 9.

[0059] The needle plug 150 and the needle cannula 104 may be assembled so that the proximal end 104p of the needle cannula 104 is mounted near the distal end 150d of the needle plug 150. As a result, the needle cannula 104 may deflect so that the distal end104d is no longer aligned with the syringe tip 106. The distal end 104d of the needle cannula 104 may become wedges against the distal wall of the syringe barrel, preventing further use of the syringe assembly 100. This feature relies on deflection of a cantilever beam due to weight. The further the load or weight of the needle cannulaP-30479.W001 PATENT14104 is from the fixed support of the needle plug, the greater the deflection will be, causing the needle cannula to be misaligned with the syringe tip 106.

[0060] Reference throughout this specification to "one embodiment," "certain embodiments," "various embodiments," "one or more embodiments" or "an embodiment" means that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. Thus, the appearances of the phrases such as "in one or more embodiments," "in certain embodiments," "in various embodiments," "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily referring to the same embodiment of the disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.

[0061] Although the disclosure herein provided a description with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the present disclosure without departing from the spirit and scope thereof. Thus, it is intended that the present disclosure include modifications and variations that are within the scope of the appended claims and their equivalents.

Claims

P-30479.W001 PATENT15What is claimed is:1 . A safety syringe assembly comprising: a syringe barrel comprising a barrel wall having an internal surface defining a chamber configured to contain a fluid, the barrel wall extending to a distal wall, the syringe barrel including an open proximal end configured to receive a plunger rod, a syringe tip extending from the distal wall and having a syringe tip fluid volume; the plunger rod including a proximal end having a thumb press and a distal end comprising a distal face including a peripheral surface having an integral peripheral seal that forms a seal against the internal surface of the barrel wall; and a needle assembly including a needle hub having a proximal end configured to be connected to the syringe tip and a distal end having an opening configured to receive a needle cannula, a needle plug comprising a distal end comprising a socket and a proximal end comprising a plunger connection element configured to engage a needle plug engagement element on the distal face of the plunger rod, the needle cannula having a proximal end slidably engaged within the opening in the needle hub and fitted into the socket, the needle cannula further including distal end, the needle plug slidably removable from one or more of syringe tip and the needle hub to allow the distal end of the needle cannula to be withdrawn inside at least one of the distal end of the needle hub and the syringe tip.

2. The safety syringe assembly of claim 1 , wherein the needle plug is slidably removable from the distal tip of the syringe barrel.

3. The safety syringe assembly of claim 2, the needle hub comprising external lugs and the syringe tip surrounded by a collar having an internal thread configured to threadably connect with external lugs on the needle hub.

4. The safety syringe assembly of claim 2, the needle hub comprising a Luer slip fitting and the syringe tip comprising a Luer slip fitting configured to slidably receive the needle hub.P-30479.W001 PATENT165. The safety syringe assembly of claim 2, wherein the plunger connection element comprises a stem with an enlarged head configured to engage the needle plug engagement element comprising a receptacle.

6. The safety syringe assembly of claim 2, wherein the needle plug fills at least 80% of the syringe tip fluid volume prior to removal of the needle plug from the syringe tip.

7. The safety syringe assembly of claim 2, wherein the needle plug fills at least 95% of the syringe tip fluid volume prior to removal of the needle plug from the syringe tip.

8. The safety syringe assembly of claim 2, wherein the needle plug fills at least 99% of the syringe tip fluid volume prior to removal of the needle plug from the syringe tip.

9. The safety syringe assembly of claim 2, wherein the distal end of the needle plug provides a contact surface and the syringe tip includes a shoulder providing a stopping surface that engages the contact surface of the needle plug to prevent the needle plug from being forced through the syringe tip.

10. The safety syringe assembly of claim 9, wherein the needle plug is slidably removable from the distal tip of the syringe barrel to allow the distal tip of the needle cannula to be withdrawn inside the syringe tip and to prevent contact with the distal tip of the needle cannula.1 1. The safety syringe assembly of claim 10, wherein the proximal end of the needle cannula is held within the socket by a friction interference fit to provide a holding force sufficient to slidably move the needle plug so that the distal tip of the needle cannula is moved inside the syringe tip.

12. The safety syringe assembly of claim 11 , wherein the proximal end of the needle cannula is further held within the socket by an adhesive.

13. The safety syringe assembly of claim 1 1 , wherein the a plunger connection element is configured to engage a needle plug engagement element when the plunger rod isP-30479.W001 PATENT17 moved in a distal direction and to allow the needle plug and the needle cannula to be moved in a proximal direction by moving the plunger rod in proximal direction.

14. The safety syringe assembly of claim 2, wherein the distal end of the needle plug provides a contact surface and the needle hub includes a shoulder providing a stopping surface that engages the contact surface of the needle plug to prevent the needle plug from being forced through the syringe tip.

15. The safety syringe assembly of claim 14, wherein the proximal end of the needle cannula is held within the socket by a friction interference fit to provide a holding force sufficient to slidably moved the needle plug so that the distal tip of the needle cannula is moved inside the distal end of the needle hub and to prevent contact with the distal tip of the needle cannula.

16. The safety syringe assembly of claim 15, wherein the proximal end of the needle cannula is held within the socket by a friction interference fit to provide a holding force sufficient to slidably move the needle plug so that the distal tip of the needle cannula is moved inside the distal end of the needle hub and to prevent contact with the distal tip of the needle cannula.

17. The safety syringe assembly of claim 16, wherein the proximal end of the needle cannula is further held within the socket by an adhesive.

18. The safety syringe assembly of claim 16, wherein the a plunger connection element is configured to engage a needle plug engagement element when the plunger rod is moved in a distal direction and to allow the needle plug and the needle cannula to be moved in a proximal direction by moving the plunger rod in proximal direction.

19. The safety syringe assembly of claim 1 , further comprising a tubular adapter comprising a proximal end and a distal end, the tubular adapter configured to cover the distal end of the needle cannula and further comprising a filter element configured to filter particles from a liquid medium on the distal end of the tubular adapter.P-30479.W001 PATENT1820. The safety syringe assembly of claim 1 , the plunger rod comprising a hollow cavity configured to receive the needle hub and the needle cannula to retract within the plunger rod to prevent reuse of syringe assembly.21 . The safety syringe assembly of claim 1 , the internal surface of the barrel wall including an undercut adjacent to the proximal end of syringe assembly, the undercut configured to receive the peripheral surface of the plunger rod to lock the plunger rod and place to prevent reuse of the syringe assembly.

22. The safety syringe assembly of claim 20, wherein the needle cannula and the needle plug are configured so that when the needle plug and the needle cannula have been retracted within the chamber, the distal end of the needle cannula becomes misaligned with the syringe tip to further prevent reuse of the syringe assembly.

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