Syringe Assembly

Abstract

The syringe assembly (10, 80, 132, 192) includes a syringe barrel (12, 86, 134, 194) having a proximal end and a distal end, a needle (18, 89, 140, 200) coupled to the distal end of the syringe barrel, a body (22, 142, 202) coupled to the syringe barrel, and a movable shield (24, 82, 164, 222) for axial movement between a first position in which the needle is exposed and a second position in which at least a portion of the needle is covered. The body (22, 142, 202) is configured to allow the shield (24, 82, 164, 222) to move to the second position and to retain the shield in the second position. The shield (24, 82, 164, 222) can slide axially, rotate relative to the body, or slide laterally relative to the body when the shield is in the second position.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 62 / 696,036, filed July 10, 2018, which is incorporated by reference in its entirety.

[0002] The present invention relates to a syringe assembly having a movable member for varying the length of the exposed portion of the needle. The syringe has a movable shield that moves relative to the syringe body to shorten the length of the exposed end of the needle and limit the depth of needle penetration into a patient. [Background technology]

[0003] Needle lengths in the 4 to 5 mm range can be difficult to insert into a container or vial for aspirating due to their short length, which requires that the needle pierce the septum in the vial in a straight line to ensure penetration and reduce the risk of the needle bending.

[0004] The insertion of the needle into the patient's skin is determined mainly based on the characteristics of the needle and not the characteristics or structure of the needle support as disclosed in Needle Insertion Modeling in Identifiability and Limitations (L. Barbe, Biomedical Signal Processing and Control 2 (207) 191-198). The insertion of the needle into the patient's skin is usually classified into three stages that affect the injection depth. The first stage corresponds to the initial contact of the skin with the needle, where the tissue is deformed without puncturing the surface of the skin. The second stage shows the puncture of the skin and the relaxation of the skin when the needle insertion force is stopped. The third stage shows the outward pulling or stretching of the skin as the needle is withdrawn.

[0005] The length of the needle, such as a needle having a length of about 4 mm to 5 mm, is adapted to inject a drug to a specified target depth in the subcutaneous region. The present invention provides a structure that allows the needle to be consistently inserted to a desired target depth. A conventional pen needle has a cannula supported on an axial post extending from a hub. The post defines a narrow portion and a relatively wide base that does not contact the skin during injection. In other pen needles known in the art, the distal face of the hub that is positioned against the injection site may be relatively large and may include a slight taper at the end. When the cannula is inserted at an angle to the surface of the patient's skin, the end of the hub may engage the skin.

[0006] Various injection devices have been manufactured such that the support structure does not contact the skin during injection or removal of the needle. Other devices have been proposed to be positioned such that the end face of the device contacts the surface of the skin in order to limit the depth of penetration into the patient.

[0007] Pen syringe delivery devices facilitate the self-administration of parenteral medications. The pen needle is a component of a needle-based injection system and consists of a double-ended cannula assembled to a plastic hub using adhesive. The hub has internal threads that allow it to be attached to the pen syringe device. Attachment of the pen needle allows the proximal end of the cannula to penetrate the rubber septum of the medication cartridge to create a fluid flow path. Maintaining glycemic control in many diabetic patients is accomplished by administering multiple daily injections of insulin into subcutaneous (SC) tissue using a pen syringe delivery device, a convenient and discreet alternative to vials and syringes. Many pen syringes are commercially available in disposable or multi-use configurations, each offering a variety of patient-centric features. The distal pen needle cannula interfaces with the delivery site, providing a conduit for delivery. The pen needle design aims to allow consistent delivery to the target tissue space, minimize leakage of injectate, and reduce pain / discomfort and site effects such as bleeding and bruising associated with injection. The primary design features, needle length / gauge and hub face geometry, along with the delivery system mechanism and injection technique, determine the success of the injection.

[0008] Injections can be administered in the intradermal, subcutaneous, and intramuscular (IM) regions of the skin. For many types of injectable drug therapies, including insulin, the SC region is preferred for administration of injections. See, for example, Lo Presti et al., Skin and Subcutaneous Thickness at Injection Sites in Diabetic Children in Ultrasound Findings and Injection Recommendations, Pediatric Diabetes (2012).

[0009] An example of a prior device is disclosed in U.S. Patent No. 9,937,299, which is a syringe with an assembly for adjusting the depth of needle penetration. The assembly includes a collar attached to the syringe that is movable relative to the syringe. Summary of the Invention [Problem to be solved by the invention]

[0010] While conventional devices are generally suitable for their intended uses, there is a continuing need for improved devices for controlling the depth of cannula penetration to deliver drugs or agents to selected target areas. [Means for solving the problem]

[0011] The present invention relates to a syringe assembly for modifying the exposed length of the distal end of the needle to aid in filling and / or aspirating the syringe and to limit the depth of penetration into a patient's skin. The present invention in one embodiment comprises a syringe assembly providing a needle having a first exposed length for filling and aspirating the syringe and a second exposed length for injecting a substance to a desired depth into the skin. In the described embodiment, the second exposed length of the needle is less than the first exposed length. The syringe assembly has a moveable shield for covering a portion of the needle to reduce the effective length of the exposed portion of the needle to control the depth of needle penetration into the patient.

[0012] The syringe assembly of one embodiment includes a syringe barrel and a needle extending from a distal end of the syringe barrel. A movable shield member is coupled to the syringe barrel for sliding movement relative to the needle and syringe body. The movable shield member slides between a first retracted position exposing a first length of the needle for filling the syringe with a substance from a container or reservoir and a second position extending to at least partially cover the proximal end of the needle to reduce the length of the exposed portion of the needle. In one embodiment, the movable shield member has a collar at a distal end that moves axially over the proximal end of the needle to reduce the length of the exposed portion of the needle extending from the syringe and limit the depth of needle penetration into the patient.

[0013] In one embodiment, the syringe assembly includes a syringe barrel with a body attached to a distal end. A movable shield member is attached to the body for sliding between a retracted position to expose the needle on the syringe and an extended position to cover a portion of the proximal end of the needle. The movable shield member includes a retention mechanism for retaining the movable shield member in the extended position during use of the syringe. The movable shield member slides axially over the end of the syringe relative to a longitudinal axis of the syringe.

[0014] In one embodiment, the syringe barrel has a movable shield member that slides between a retracted position to expose the needle and an extended position to cover a portion of the needle, the shield member having at least one retention feature that cooperates with a retention feature of the syringe to retain the shield member in the extended position.

[0015] In one embodiment, the movable shield member slides to an extended position where a retention feature engages with a retention feature on the syringe to retain the movable shield member in the extended position. In other embodiments, the movable shield member rotates in the extended position to engage with the retention feature. In another embodiment, the movable shield member is configured to slide laterally relative to a longitudinal axis of the syringe when the shield member is in the extended position to engage with the retention feature and retain the shield member in the extended position. The shield member can also have a slot that engages with a detent on the syringe, the slot having a first portion for permitting axial sliding and rotational movement when the shield member is in the extended position.

[0016] The features of the present invention are achieved essentially by providing a syringe assembly comprising a syringe barrel having a proximal end and a distal end, a needle hub at the distal end of the syringe barrel, and a movable shield member movable relative to the syringe barrel between a first position in which the needle is exposed and a second position in which the needle is partially covered, the shield member being configured to engage a retention feature on the syringe barrel to retain the shield member in the extended position.

[0017] The syringe assembly also includes a syringe barrel having a proximal end and a distal end, and a needle extending from the distal end of the syringe barrel. An adapter can be coupled to the distal end of the syringe barrel for supporting a movable shield member, the shield member moving between a first position for exposing a first portion of the needle having a first length and a second position for exposing a second portion of the needle having a second length less than the first length.

[0018] A method is provided for loading a syringe with a drug or other substance. The method includes providing a syringe barrel having a proximal end and a distal end, a needle extending from the distal end of the syringe barrel, and a movable shield member at the distal end of the syringe barrel. The shield member is movable between a first position exposing a first portion of the needle having a first length and a second position exposing a second portion of the needle having a second length less than the first length. The method includes moving the shield member to the first position to expose the needle for puncturing a septum of a container or vial and retracting a plunger of the syringe to aspirate the substance into the syringe. The shield member is moved to the second position to expose the second portion of the needle for penetrating the skin of a patient for use in injecting the substance to a controlled depth in the patient.

[0019] These and other features of the present invention will become apparent from the following detailed description of the invention, which, taken in conjunction with the drawings, disclose various embodiments of the invention. [Brief description of the drawings]

[0020] Below is a brief description of the drawings.

[0021] [Figure 1] FIG. 1 is a perspective view of a syringe assembly in one embodiment of the present invention. [Diagram 2] FIG. 2 is a side view of the syringe assembly of FIG. 1. [Diagram 3] 2 is a perspective view of the syringe assembly in the embodiment of FIG. 1 showing the movable shield member in a retracted position. [Figure 4] FIG. 2 is a perspective view of the syringe barrel of the embodiment of FIG. 1 without a movable shield member; [Diagram 5] FIG. 4 is a perspective view of a movable shield member. [Figure 6] FIG. 13 is a cross-sectional view of the shield member of the syringe in the retracted position. [Figure 7] FIG. 13 is a cross-sectional side view of the shield member of the syringe in the extended position. [Figure 8] FIG. 13 is a perspective view of a syringe assembly in another embodiment. [Figure 9] FIG. 9 is a side view of the syringe assembly of FIG. [Figure 10] 9 is a perspective view of the shield member in the embodiment of FIG. 8. [Figure 11] FIG. 13 is a cross-sectional view showing the needle shield member in the retracted position. [Figure 12] 1 is a cross-sectional view of the syringe assembly showing the needle shield member in an extended position; FIG. [Figure 13] 13 is a side view of a syringe assembly in a further embodiment, showing a shield member in a retracted position. FIG. [Figure 14] FIG. 14 is a perspective view of the syringe assembly of FIG. [Figure 15] 14 is a cross-sectional view of the shield member in the embodiment of FIG. 13. [Figure 16] FIG. 13 is a side view of a shield member in an alternative embodiment. [Figure 17] 14 is a side view of the syringe and adapter showing the guide groove of the shield member of FIG. 13. [Figure 18] FIG. 13 is a side view of the shield member in the retracted position. [Figure 19] FIG. 4 is a side view of the shield member in an extended state. [Figure 20] FIG. 13 is a side view of a syringe assembly in another embodiment. [Figure 21] FIG. 21 is a perspective view of the syringe assembly of FIG. [Figure 22] FIG. 21 is a side view of the syringe and adapter of FIG. 20, showing the connection mechanism without the shield member. [Figure 23] 21 is a perspective view of a shield member in the embodiment of the syringe assembly of FIG. 20. [Figure 24] FIG. 21 is a perspective view of the shield member of the alternative embodiment of FIG. 20. [Diagram 25] FIG. 24 is a cross-sectional view of the shield member of FIG. 23. [Figure 26] FIG. 4 is a side view showing the shield member in the retracted position. [Figure 27] FIG. 13 is a side view showing the shield member in an extended position. [Figure 28] FIG. 13 is a perspective view of a shield and an adapter in another embodiment. [Figure 29] 29 is a perspective view of the embodiment of FIG. 28 showing the shield in an extended position. [Diagram 30] FIG. 29 is a cross-sectional view of the adapter of FIG. 28. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The syringe assembly of the present invention refers to a syringe having a needle or cannula for injecting a drug or other substance into a patient. The terms needle and cannula are used interchangeably herein and refer to a thin tubular member having a sharp end for insertion into an injection site of a subject. The distal direction is the direction toward the injection site and the proximal direction is the opposite direction. The axial direction refers to the direction along or parallel to the longitudinal axis of the needle and needle hub, and the radial direction refers to the direction perpendicular to the axial direction.

[0023] The thickness of the intradermal layer in adults is generally about 2-3 mm, so that the depth of the intradermal injection ranges from about 3 mm or less, measured from the outer surface of the skin. The thickness of the subcutaneous layer varies depending on the patient's age, sex, body mass index (BMI), and the part of the body where the injection is performed. The subcutaneous region has an average thickness of about 7 mm to about 15 mm. Insulin is preferably delivered to the subcutaneous region. The syringe assembly is configured to control the depth of needle penetration to a selected depth, for example, a depth of 3 mm or less.

[0024] The syringe assembly is suitable for use in a method of injection and in a method of injecting a drug into a patient. The above description of the preferred embodiment should not be considered as limiting the invention, which is defined by the appended claims. The present disclosure is intended to enable those skilled in the art to make variations of the invention described without departing from the scope of the invention. The numerical limitations herein in the present specification and claims are understood to be qualified by the modifier "about", and minor deviations that achieve equivalent results are within the scope of the invention. Features disclosed in connection with one embodiment or an independent claim or limitations of a dependent claim may be combined with another embodiment or a different independent claim without departing from the scope of the invention.

[0025] The syringe assembly is configured to introduce a substance, such as a medication, to a selected depth in a patient while providing a needle length sufficient to facilitate loading or withdrawing the substance into the syringe. With reference to Figures 1-7, syringe assembly 10 includes a syringe barrel 12 and a needle shield assembly 20. The syringe barrel has a proximal end 14 and a distal end 16. The proximal end 14 has an open end that receives a movable plunger having a stopper for dispensing the substance contained in the syringe assembly. For ease of illustration, the plunger has a known configuration for sliding axially within the syringe barrel to load the syringe and dispense the contents of the syringe, but is not shown in the drawings.

[0026] A needle hub is at the distal end 16 of the syringe barrel 12 for supporting a needle 18 in a known manner. The needle 18 extends axially from the needle hub a distance to penetrate the patient's skin and deliver the substance to the patient. The needle hub may be integrally formed with the distal end of the syringe or may be configured as a separate member for coupling to the distal end of the syringe barrel 12. A needle shield assembly 20 fits over the needle hub such that the needle 18 extends through the needle shield assembly. The needle shield assembly 20 may be attached to the needle hub by a friction fit or an interference fit.

[0027] The needle shield assembly 20 in the embodiment shown has a body 22 and a movable shield 24 that moves on the body 22 axially and rotationally relative to the longitudinal axis of the syringe and body 22. The body 22 can be formed with the syringe barrel 12 or can be a separate adapter unit that is coupled to the end of the syringe barrel 12 or to a needle hub. In the embodiment shown, the body 22 is a separate adapter member having a central opening for fitting and coupling to the distal end of the syringe and needle hub through which the needle 18 extends, as shown in FIG. 4. The body 22 has a substantially cylindrical section 26 having a proximal end 28 and a distal end 30.

[0028] The body 22 has a retention mechanism 32 for retaining the shield 24 on the body 22 and the syringe. The retention mechanism 32 has a base 34 with configuration for cooperating with the shield member 20. The base 34 in the illustrated embodiment extends from the distal end of the body 22 to a height sufficient to allow the shield 20 to move between a retracted position and an extended position. The base 34 as shown in FIG. 4 is formed with at least one, and typically two, flat sidewall surfaces 36 extending axially and a curved or rounded end surface 38 extending between the flat surfaces 36. The curved surface 38 defines an outer dimension that substantially corresponds to the outer dimension of the body 22. The flat surface 36 converges with a distal surface 40 at the distal end of the body 22.

[0029] The post 42 extends axially from the body 22. As shown in FIG. 4, the post 42 has a distal end portion 50 having a substantially cylindrical configuration with a distal end face 44. An opening 46 in the distal end face 44 receives the needle 18 extending from the distal end of the syringe. The post 42 has a first section 48 at a proximal end adjacent the base 34 and a substantially cylindrical second section 50 forming the distal end of the post 42. The first section 48 is formed with a plurality of flat faces 52. In the embodiment shown, the first section 48 has eight faces 50 forming a hexagon. A rib 54 projects radially outward from the post 42 at the distal end of each face 52 of the first section 48. In the embodiment shown, the rib 54 on each face 52 extends around the circumference of the post 42 and extends a radially outward distance to retain the shield 24 on the post 42. The rib 42 has a bottom surface 56 that extends substantially perpendicular to the longitudinal axis of the post 42 and a top surface 58 that is angled to allow the shield 24 to snap onto the post 42 .

[0030] 5, the shield 24 has a substantially cylindrical side wall 60 with a bottom wall 62. The bottom wall 62 has an opening 64 configured to receive the post 42 and base 34. The opening 64 in the bottom wall 62 is shaped and configured for axial sliding on the base 34 where the shield 24 slides between a first retracted position shown in FIGS. 2, 3 and 6 to a second extended position shown in FIG. 7. The opening 64 has inner side edges 66 that complement the flat surface 52 of the post 42 for axial sliding on the post 42. The width of the opening 64 between the inner edges 66 corresponds substantially to the diameter of the first section 48 and is less than the diameter of the opposing rib 54. The side wall 60 has an axial length that slides from the distal end of the post 42 past a portion of the distal end of the needle 18 as shown in FIG. In the embodiment shown, the side wall 60 has outwardly extending tabs 70 to assist the user in moving the shield 24 on the post 42. The tabs 70 are located on opposite sides of the shield in the embodiment shown. The tabs can be located in other suitable locations that allow the user to move the shield axially and rotationally relative to the syringe.

[0031] The shield 24 is positioned on the post 42 with the base 34 facing into the opening 64 of the bottom wall 62. As shown in FIG. 3, the bottom wall 62 is captured by the ribs 54 to hold the shield on the base 34. The shield 24 can slide axially on the base 34 from a retracted position where the bottom wall 62 contacts the distal surface 40 of the body 22 to an extended position where the bottom wall 62 contacts the bottom surface of the ribs 54. The side wall 60 has an axial length such that the needle 18 is exposed a first length in the retracted position and the side wall 60 covers a portion of the needle in the extended position. The needle 18 has a length sufficient to be inserted through a septum of a drug container for filling and aspirating a syringe when the shield 24 is in the retracted position. In some cases, the overall length of the needle may be longer than the desired penetration depth.

[0032] The syringe is filled in the standard manner by retracting the plunger to withdraw the substance from the container for use in injecting the substance into a patient. After the syringe is filled and the needle is separated from the septum of the container, the shield 24 can be moved to an extended position shown in FIG. 6 by sliding axially on the base 34. The side wall 60 of the shield 24 has an axial length over which the proximal end of the needle 18 is covered, as shown in FIG. 7, such that when the shield is in the extended position, the exposed length of the needle 18 is less than the exposed length of the needle when the shield is in the retracted position. The exposed length of the needle is defined by the length of the needle between the distal end face of the side wall 60 of the shield 24 and the distal tip of the needle 18. The shield 24 is moved to an extended position on the base 34 where the bottom wall 62 slides over the end of the base 34, the bottom wall 62 is aligned with the first section 48 of the post 42, and the shield is in the extended position. The shield is manually rotated about the post 42 such that the flat inner edge 66 of the opening 64 in the bottom wall 62 is captured between the distal end face 44 of the base 34 and the rib 54 to hold the shield 24 in the extended position. The straight inner edge 66 of the bottom wall 62 of the shield 24 contacts the flat surface 52 of the post when the shield is moved to the extended position. As the inner edge 66 slides over the flat surface 52, the angle between adjacent surfaces 52 forms a ratchet mechanism as the shield rotates, providing a tactile or audible indication that the shield has rotated to a position where it cannot be moved back to its original retracted position. The flat surface 52 holds the angular position of the shield 24 and resists rotation back to the original position where the shield can be retracted.

[0033] As shown in FIG. 7, the shield 24 is moved to an extended position to cover a portion of the proximal end of the needle 18, thereby reducing the effective length of the exposed portion of the needle that protrudes beyond the distal surface of the sidewall of the shield 24. The needle 18 can pierce the skin to a penetration depth where the surface of the skin contacts the distal end 68 of the sidewall 60 of the shield 24. Rotating the shield 24 to the position shown in FIG. 7 where the bottom wall 62 contacts the surface 40 of the base 34 prevents the shield from retracting when it contacts the patient's skin during insertion of the needle into the patient. In the embodiment shown, the distal surface of the shield slides past the distal surface 44 of the post 42 to form a recessed area in the open end of the shield. The distance between the distal surface of the post and the distal end of the shield defines the depth of the recess and corresponds to the difference in the exposed length of the needle when the shield is in the retracted and extended positions. The needle 18 has an exposed length of approximately 3-4 mm as shown in FIG. 7. The needle 18 has a length extending from the end of the post 42 sufficient to penetrate the septum to fill the syringe.

[0034] In another embodiment, a syringe assembly 80 and shield assembly 82 are shown in FIGS. 8-12 to reduce the effective exposed length of the needle 84. The syringe assembly 80 is similar to the syringe of the previous embodiment and includes a syringe barrel 86 having an open proximal end 88 for receiving a plunger and a distal end 90 supporting the needle 84. The distal end 90 of the syringe barrel in the illustrated embodiment has a tip 92 having a substantially circular sidewall 94 and a distal end surface 96. The sidewall of the tip 92 is spaced inwardly from the sidewall of the syringe barrel 86 to form an axially facing annular shoulder 98. As shown in FIG. 11 of FIG. 12, the needle 84 extends axially from the tip 92 of the syringe barrel 86. In an alternative embodiment, the tip 92 can be a separate member that fits into the syringe barrel or needle hub with the needle extending through an opening in the tip 92.

[0035] The shield assembly 82 includes a shield body 100 that cooperates with a detent 102 on the tip 92 of the syringe barrel 86. The shield 100 is shaped and configured to slide axially over the tip 92 and laterally relative to the longitudinal axis of the syringe 86 and tip 92. The shield 100 has an axial length to expose a first length of the needle 84 when in the retracted position shown in FIG. 11 and to expose a second length of the needle 84 when in the extended position shown in FIG. 12. As in the previous embodiment, the exposed length of the needle 84 when the shield 100 is in the retracted position is sufficient to allow the needle 84 to penetrate a septum of a container for filling the syringe. The exposed length is approximately 7-8 mm. The exposed length of the needle when the shield is in the extended position may be approximately 3-4 mm.

[0036] 11-12, the shield 100 has a cavity 104 at a proximal end of the shield that is sized to receive the tip 92 of the syringe assembly 82. The cavity 104 has a first portion 106, shown in FIG. 12, that is sized to receive the tip 92 of the syringe assembly. The first portion 106 has an end face 108 and an axial length that substantially corresponds to the axial length of the tip 92. The first portion 106 receives the tip 92 when the shield 100 is in the retracted first position, shown in FIG. 11, with the shield contacting the shoulder 98 and the distal end 96 contacting the end face 108. The needle 84 extends through a needle opening 110 as shown in FIG. 11 and has a first exposed length sufficient to fill the syringe.

[0037] The cavity 104 in the shield 100 is adjacent to a first portion 106 for receiving the tip 92 and has a second portion 112 having an axial length less than the axial length of the first portion 106. An angled surface 114 extends between the first portion 106 and the second portion 112. The second portion 112 has an end surface 116, shown in FIG. 11, for contacting the distal surface 96 of the shield 100 when the shield is in the second extended position shown in FIG. 12. The shield 100 in the position shown in FIG. 12 covers a portion of the proximal end of the needle 84 to reduce the effective length of the exposed portion of the needle that extends beyond the distal surface of the shield 100. In the position shown in FIG. 12, the needle 84 has an exposed length for delivering a drug to a patient.

[0038] Needle opening 110 as shown in Figure 10 has a width and length that receives needle 84 and allows shield 100 to slide laterally between the position shown in Figure 11 and the position shown in Figure 12. Needle opening 110 is aligned with cavity 104 and has dimensions that are smaller than the dimensions of cavity 104 such that tip 92 of syringe barrel 86 does not extend through needle opening 110.

[0039] In the embodiment shown, the shield 100 has an elongated configuration with side walls 118 extending a length corresponding to the longitudinal dimension of the needle opening 110. In the embodiment shown, the side walls 118 are substantially straight and parallel to one another. A guide slot 120 is formed in each side wall 118 that receives a detent 102 on the tip 92. The detent 102 captures the needle shield 100 on the tip 92 of the syringe barrel 86 while allowing axial and lateral movement of the shield 100 relative to the syringe barrel 86 and tip 92. The guide slot 120 has a first section 122 that extends in the axial direction of the shield 100 relative to the syringe barrel 86. The first section 122 has a longitudinal axial length that substantially corresponds to the length of axial shield movement between the first portion 106 and the second portion 112 of the cavity 104. The second section 124 is connected to the first section 102 by an angled portion 126. The second section 124 extends transversely to the axial direction of the first section 122 and has a length complementary to the longitudinal length of the cavity 104 and needle opening 110. In the embodiment shown, the detents 102 extend from opposite sides of the tip 92 to connect to respective guide slots 120 in the opposing sidewall 118. In alternative embodiments, a single detent and guide slot may be provided.

[0040] During use of the syringe assembly 80, the shield 100 is initially placed in the retracted position shown in FIG. 11 with the needle 84 protruding from the distal face of the shield 100 to define a first exposed length of the needle. The exposed length of the needle 84 is generally sufficient to penetrate a septum of a reservoir or container for filling the syringe in the normal manner. After filling the syringe barrel, the needle is withdrawn from the reservoir ready to use the syringe barrel. The shield 100 is moved axially away from the tip 92 such that the detent 102 slides within the first section 122, the angled section 126, and the second section 124 in the guide slot 122 to orient the shield 100 in the extended position shown in FIG. 12. The extended position of the shield 100 reduces the effective length of the exposed portion of the needle 84. Shield 100 is manually moved transversely to the longitudinal axis of the syringe barrel such that detent 102 slides in second section 124 to the position shown in FIG 12. By locating detent 102 in second transverse section 124, shield 100 is restricted from sliding axially back to the retracted position.

[0041] 13-19, another embodiment of a syringe assembly 130 as shown. The syringe assembly 130 includes a shield assembly 132 for sliding movement relative to the syringe assembly 130. The syringe assembly 130 has a syringe barrel 134 with an open proximal end 136 for receiving a plunger and a distal end 138 supporting a needle 140. In the embodiment shown in FIG. 17, a base 142 in the form of an adapter is connected to the distal end of the syringe barrel 134. The base 142 has a substantially cylindrical shape having a side surface 144 and an axial surface 146. A post 148 extends from the base with the post having an end surface 150 spaced from the surface 146.

[0042] Side 144 of base 142 includes a guide groove 152 having an angled section 154 extending between proximal end 156 and distal end 159 of base 142. The distal end of guide groove 152 is connected to a transverse surface 158 that extends in a direction substantially perpendicular to the longitudinal axis of the syringe barrel. Transverse surface 158 has a recess 160 and a detent 162 aligned with recess 160.

[0043] The shield assembly 132 includes a shield 164 having a substantially cylindrical body 166 with inner dimensions corresponding to the outer dimensions of the base 142 for sliding the shield 164 relative to the base 142. The body 166 has a proximal end 168 and a distal end 170 with an annular collar 172 extending axially from the distal end. The collar 172 in the embodiment shown has a diameter larger than the diameter of the body 166. Tabs 174 are provided on the outer surface of the body 166 to assist the user in manipulating the shield 164 relative to the base 142. In the embodiment shown in FIG. 15, a single tab 174 is shown. In an alternative embodiment shown in FIG. 16, multiple tabs 174 or flanges can be provided to assist the user in manipulating the shield.

[0044] The detent 176 projects inwardly from an inner surface 178 of the body 166. In the embodiment shown, the detent 176 is oriented toward the proximal end 168 and is configured to slide within the guide groove 152. During use of the syringe assembly, the shield 164 is initially oriented in a retracted position shown in FIGS. 13 and 18, where the detent 176 is received in the proximal end of the angled section 154 of the guide groove 152. The shield 164 in the position shown in FIG. 18 provides an exposed portion of the needle 140 with an effective length to penetrate a septum of a drug reservoir for filling the syringe. After filling the syringe, the shield 164 is manually moved to an extended position shown in FIG. 19. The detent 176 slides within the angled section 154, causing the shield to rotate about the axis of the base 142 until the detent reaches the distal end of the angled section. The shield 164 can be rotated about the axis of the base 142 about which the detent 176 slides within the transverse surface 158. The detent 176 slides into the detent 160 and past the detent 176 to reach the end 180, which captures the detent and resists rotation of the shield back to its original position. The shield 164 in the extended position shown in FIG. 19 provides an exposed portion of the needle 140 with a length that is shorter than the exposed length of the needle, and the shield in the retracted position. The syringe assembly can then be used to inject the patient where the needle 140 penetrates the patient's skin to a depth that substantially corresponds to the exposed length of the needle shown in FIG. 19. The distal end face 182 of the collar 172 contacts the patient's skin to limit the depth of penetration of the needle.

[0045] In an embodiment, the guide grooves are formed on the adapter and the detents are formed on the shield, or the parts can be reversed with the guide grooves formed on the shield and the detents formed on the adapter.

[0046] 20-27, another embodiment of a syringe assembly 190 is shown having a shield 192. Syringe assembly 190 is similar to the previous embodiment and includes a syringe barrel 194 having an open proximal end 196 for receiving a plunger and a distal end 198. A needle 200 is coupled to and extends axially from the distal end of the syringe barrel.

[0047] In the embodiment shown, the adapter 202 is coupled to the distal end of the syringe barrel 194. In alternative embodiments, the adapter may be integrally formed with the syringe barrel. The adapter 202 has a substantially cylindrical base 204 and a cylindrical tip 206 extending from the distal end of the base 204. A needle 200 extends from the tip 206, as shown in FIG.

[0048] The base 204 has a longitudinally extending guide rib 208 extending between the proximal and distal ends of the base 204. The proximal end of the guide rib 208 has a radially outwardly projecting lip 210 forming a stop for the sliding movement of the shield 192. An annular flange 212 is provided at the distal end of the base 204 and extends around the circumference of the base. In the embodiment shown, the flange 212 has an inclined distal face 214 and a substantially flat proximal face 216 forming a radially extending surface substantially perpendicular to the longitudinal axis of the base and the syringe assembly. The annular rib 218 is spaced from the flange 212 to form an annular recess 220 in the illustrated embodiment. The rib 218 has a radial dimension that is smaller than the radial dimension of the flange 212.

[0049] The shield 192 has a cylindrical body 222 formed by a cylindrical sidewall and having an axially open passage 224. The axial passage 224 has a dimension that substantially corresponds to the outer surface of the guide rib 208 to allow the shield 192 to slide axially over the guide rib 208 and the adapter 202. The distal end of the body 222 has an annular collar 226 that extends distally from the body 222. The collar 226 has a diameter that is larger than the diameter of the body 222, as shown in FIG. 23. The outer surface of the body 222 is provided with a protrusion 228 to assist the user and aid in manipulating the shield relative to the adapter. In the embodiment shown in FIG. 23, two protrusions are spaced apart on opposite sides of the body 222. In the embodiment shown in FIG. 24, the protrusion 228 extends axially and has a dimension sufficient to allow the user to manipulate the shield.

[0050] 25, the inner surface of the body 222 includes at least one inwardly extending detent 230. The detent 230 is formed at the proximal end of the body 222 and has a radial dimension to slide axially between adjacent guide ribs 208. The detent 230 has an axial dimension sufficient to fit within the annular recess 220. The shield 192 slides over the distal end of the adapter such that the detent 230 slides over the angled surface 114 of the flange 212. The shield 192 is initially placed in a retracted position shown in FIG. 26, where the proximal end of the body 222 contacts the lip 210 of the guide rib 208. In the position shown in FIG. 26, the needle 200 has an exposed length to easily fill the syringe by penetrating the septum of the reservoir. The shield 192 is then manually moved by sliding it axially towards the distal end of the adapter 202 to the position shown in FIG. 27 where the detent 230 slides over the rib 218 and snaps into the annular recess 220. In the position shown in FIG. 27, the distal surface 232 of the collar 226 is formed to create an exposed length of the needle that has a length that is shorter than the length when the shield is in the retracted position of FIG. 26. The rib 218 and the annular recess 220 are sized to hold the detent 230 with sufficient force to resist sliding movement of the shield into the retracted position during penetration of the needle into the patient. The needle penetrates the patient's skin to a depth where the distal surface 232 of the collar 226 contacts the surface of the skin to limit the depth of penetration.

[0051] 28-30, another embodiment of a moveable shield and adapter assembly 350 is shown. An adapter 352 is coupled to the syringe barrel as in the previous embodiment, and a shield 354 slides over the adapter between a retracted position and an extended position. The adapter 352 includes an open proximal end forming an internal passage 356 having ribs or other features for coupling the adapter 352 to the distal end of the syringe barrel. The body has a longitudinally extending slot 360 with a detent 362. The detent 362 has an inclined surface 364 facing the proximal end toward the syringe barrel and a flat surface 365 extending perpendicular to the central axis and facing the distal end of the body. Opposite the slot 360 and the detent 362 is a recess 366 on the outer surface. The recess 366 has a flat surface 368 extending perpendicular to the central axis and an inclined surface 370.

[0052] The shield 354 has a substantially cylindrical body 372 with a central passage 374 having dimensions corresponding to those of the adapter 352. A detent 376 projects inwardly from a sidewall of the body 372 to slide longitudinally within the slot 360 and engage a detent 362 therein. The detent 376 extends perpendicular to the central axis and has a flat surface 378 facing the proximal end and an angled surface 380 facing the distal end. The detent 376 slides within the slot 360 with sliding movement of the shield 354 over the adapter 352. The detent 376 engages the detent 362 to form a stop member to limit sliding in the proximal direction. The slot 360 has an end wall at the distal end of the slot to limit sliding movement of the shield in the distal direction.

[0053] The shield 354 has a flexible tab 384 cantilevered to the body of the shield for engaging the recess 366 of the adapter 352. The flexible tab 384 is hinged to the body of the shield and can bend outwardly relative to the body. The distal end of the tab 384 has an inwardly extending detent 386 that engages a flat side of the adapter. The detent 386 has an inclined distal surface 388 and a flat surface 390 that extends perpendicular to the longitudinal axis. The detent 386 is received in the recess of the adapter when the shield is in the retracted position. The shield 354 is pushed distally by a thumb tab 392 that slides out of the recess and hooks onto the end of the adapter to cover a portion of the needle and the detent 376 engages the end wall of the slot 360, as shown in FIG. 29. Flexible tabs 384 can be bent outward to release detents 386 from the end of adapter 352 and allow shield 354 to slide to the retracted position of Fig. 28, exposing the needle for filling and aspiration. A cover 394, shown in Fig. 30, can be attached to the end of adapter 352 to cover the exposed end of the needle until ready for use.

[0054] The above-mentioned embodiments and advantages are merely illustrative and should not be construed as limiting the scope of the present invention. The description of alternative embodiments is intended to be illustrative and not limiting the scope of the present invention. Various modifications, alternatives, and variations will be apparent to those skilled in the art and are intended to be included within the scope of the present invention. The features of different embodiments and claims can be combined with each other unless they are mutually inconsistent. Therefore, all such modifications are intended to be included within the scope of the present invention as defined in the appended claims and their equivalents.

Claims

1. 1. A syringe assembly comprising: a syringe barrel having a proximal end and a distal end; a needle extending from the distal end of the syringe barrel; a shield member disposed on a body coupled to the syringe barrel for movement between a first position in which a first length of the needle is exposed and a second position in which a portion of the needle is covered with a second length of the needle that is exposed, the second length being less than the first length of the needle, the shield member having a mechanism configured to retain the shield member in the second position; a shield member that is held relative to the body in a state where it can only move axially distally when the shield member is in the first position, and that is rotatable or slidable laterally relative to the body when the shield member is in the second position to hold the shield member in the second position exposing the second length of the needle.

2. 2. The syringe assembly of claim 1, wherein the shield member has a side wall and a bottom wall with an opening for axial movement over the body.

3. The bottom wall is disposed at a proximal end of the shield member and includes the opening, the body includes a post at a distal end of the body, the post having an outer surface that complements an inner edge of the opening in the shield member; an inner edge of the opening is aligned with a complementary outer surface of the post when the shield member is in the first position; 3. The syringe assembly of claim 2, further comprising a recess at a distal end that receives said bottom wall of said shield member such that said shield member is rotatable relative to said body when said shield member is in said second position.

4. 4. The syringe assembly of claim 3, wherein the strut has an annular rib extending radially outward to capture the bottom wall of the shield member between the annular rib and a distal surface of the body, and the strut has a dimension that allows the shield member to be rotated when the shield member is in the second position.

5. 2. The syringe assembly of claim 1, wherein the body has an outwardly extending detent and the shield member has a recess that receives the detent, the recess having a configuration that allows the shield member to move axially relative to the body from the first position to the second position and to move laterally when the shield member is in the second position.

6. 6. The syringe assembly of claim 5, wherein the recess has a first section extending axially relative to the syringe and a second section extending laterally relative to the first section to allow the shield member to slide laterally.

7. 7. The syringe assembly of claim 6, wherein the shield member has an opening to receive the needle, the opening having a dimension that allows the shield member to slide laterally to the second position.

8. The syringe assembly of claim 6, wherein the first section of the recess is oriented obliquely relative to an axial direction of the body.

9. 1. A method for filling a syringe, comprising: providing a syringe barrel having a proximal end and a distal end, a needle coupled to the distal end of the syringe barrel, a body coupled to the distal end of the syringe barrel, and a shield member adapted to move on the body between a first position for exposing a first portion of the needle having a first length and a second position for exposing a second portion of the needle having a second length less than the first length; moving the shield member to the first position to expose the needle and fill the syringe, and holding the shield member axially movable only distally relative to the body; moving the shield member to the second position to expose a second portion of the needle and holding the shield member in a rotatable or laterally slidable state relative to the body; The method according to claim 1,

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