Adapter and syringe

Abstract

The syringe assembly includes a syringe barrel having a proximal end and a distal end, a needle hub supporting a needle and coupled to the distal end of the syringe barrel, an adapter coupled to the hub, and the needle extending from the adapter to define a needle length for injecting a substance into a patient, the adapter having a diameter larger than the diameter of the syringe and including a distal surface having a shape and dimension configured to control the needle penetration depth into the patient, and a proximal surface forming a finger grip.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 042,495, filed June 22, 2020, which is incorporated herein by reference.

[0002] The present invention relates to a syringe assembly having an adapter for providing control over skin contact surface, limiting needle penetration depth, handling the syringe during aspiration, and varying the length of the exposed portion of the syringe needle. [Background technology]

[0003] Needle lengths ranging from 4 mm to 6 mm are commonly used to inject medications into patients. The needles in some devices are long enough to be inserted into and withdraw from a container or vial. The needle length requires that the needle penetrate the vial septum in a straight line to ensure penetration and reduce the risk of the needle bending.

[0004] Needle insertion into a patient's skin is primarily determined by the characteristics of the needle, not the features or structure of the needle support. Needle insertion into a patient's skin is generally divided into three stages that affect injection depth. The first stage corresponds to the initial contact of the needle with the skin, which deforms the tissue without puncturing the surface of the skin. The second stage represents the puncture and relaxation of the skin when the needle insertion force ceases. The third stage involves pulling or stretching the skin outward as the needle is withdrawn.

[0005] The needle length, such as a needle having a length of approximately 4 mm to 6 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 the desired target depth. One example of a delivery device includes a cannula supported on an axial strut extending from a hub. The strut forms a narrow portion and a relatively wide base that does not contact the skin during injection. In other devices known in the art, the distal face of the hub that is positioned against the injection site may be relatively large and may have a slight taper at the end. When the cannula is inserted at an angle relative to the surface of the patient's skin, the end of the hub can engage the skin.

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

[0007] Injections can be performed in the intradermal, subcutaneous, and intramuscular (IM) regions of the skin. For many types of injectable medications, including insulin, the SC region is preferred for administering injections.

[0008] 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 for delivering drugs or agents to selected target areas. Summary of the Invention [Problem to be solved by the invention]

[0009] The present disclosure relates to a syringe assembly having a syringe barrel and a needle for injecting a medication into a patient. In one embodiment, the syringe includes a distal end shaped and configured to control the needle's penetration depth into a surface, such as a patient's tissue, through an insertion force applied by a user. The distal end of the syringe can have a shape and configuration that assists the user in handling the syringe when inserting the needle through a septum in a vial for filling and aspiration. [Means for solving the problem]

[0010] In one embodiment, the syringe assembly includes a syringe barrel and a needle or cannula extending from the distal end of the syringe barrel. The syringe barrel includes an end member forming a distal end or distal end of the syringe barrel with an axially extending cannula or needle for injecting a medication into a patient. The distal end includes an axial end face for contacting a patient's skin when the needle is inserted into the patient's skin. The axial end face has a configuration that provides a dimension or profile that controls the stretch or contour of the skin surface during injection, thereby controlling the needle's penetration depth into the skin. The distal end of the syringe barrel can include a radially extending flange or other member that allows a user to insert the needle through a septum of a vial and load the syringe. The flange can axially align the needle with the opening of the vial, orient the needle perpendicular to the plane of the septum, and help resist angled insertion of the needle into the septum.

[0011] In one embodiment, the syringe includes a syringe barrel and a plunger, the syringe barrel having a distal end supporting a needle or cannula. The distal end of the syringe barrel has an axial surface having a diameter greater than the diameter of the syringe barrel. The distal end can have a distal surface having a convex contour forming a skin-contacting surface, or a concave contour. The convex contour has a central post around the needle base that protrudes axially from the outer periphery of the axial surface. The concave contour has a central post around the needle base spaced proximally from the outer periphery.

[0012] In another embodiment, a syringe includes a syringe barrel with a distal end having an axial face of a convex contour with an annular recess about the needle, the annular recess spaced radially outward from the needle and radially inward from an outer annular surface of the axial face.

[0013] In one embodiment, the syringe has a distal face with a centrally located post that supports the needle and an annular shaped portion surrounding the post and spaced from the post to form an annular recess on the distal face, The post has a length that extends axially from the annular shaped portion and forms a surface in front of the surface of the annular shaped portion that contacts the surface of the skin during injection.

[0014] Other features of the syringe assembly include a syringe barrel having a distal end supporting a needle, and an adapter member coupled to the distal end of the syringe barrel. The adapter member can be formed integrally with the syringe barrel or as a separate member attached to the syringe barrel. The adapter member can be coupled to the distal end of the syringe barrel by friction or an interference fit, or can be secured to the distal end of the syringe barrel by bonding or adhesive, such as welding.

[0015] The features are achieved by a syringe assembly that essentially includes a syringe barrel having a proximal end and a distal end, a hub supporting a needle at the distal end of the syringe barrel, and an axial surface surrounding the needle, the axial surface having a diameter greater than the diameter of the syringe barrel and having a contour and configuration for contacting the skin to control the depth of needle penetration into a patient's skin.

[0016] The syringe features include a syringe barrel having a proximal end and a distal end, a hub supporting a needle and coupled to the distal end of the syringe barrel, and an adapter coupled to the hub of the syringe barrel. The adapter has a proximal end for coupling to the hub of the syringe barrel and a distal end forming a skin-contacting surface surrounding the needle. The adapter has a distal axial surface surrounding the needle and having a convex shape forming the skin-contacting surface. In one embodiment, the axial surface of the adapter includes an inner central post extending axially and surrounding the base of the needle, and an annular outer portion spaced from the post and having a convex circumferential surface. The distal end of the post is spaced distally from the outer portion from the convex shape of the distal surface of the adapter. The adapter has a proximal surface shaped and sized to allow a user to grasp the syringe and apply an axial force to pierce a septum of a vial to fill the syringe.

[0017] The syringe assembly may also include a syringe barrel having a needle and a distal end defining a skin-contacting surface having a concave shape. The axial surface of the syringe barrel may include an inner portion surrounding the base of the needle and an outer peripheral surface spaced axially outward from the inner portion.

[0018] In a further embodiment, a syringe assembly includes a syringe barrel having a distal end that supports a needle and an axial surface that forms a skin-contacting surface during injection of the needle into a patient, the axial surface including an inner portion having a flat annular surface that surrounds the needle and an outer circumferential surface spaced radially outward from the inner portion and having a flat axial surface oriented in the plane of the flat surface of the inner portion.

[0019] These and other features of the syringe assembly will become apparent from the following detailed description, which, taken in conjunction with the drawings, discloses various embodiments of the syringe assembly. [Brief explanation of the drawings]

[0020] Below is a brief description of the drawings. [Figure 1] FIG. 1 is a perspective view of a syringe assembly in one embodiment. [Figure 2] 2 is a side view of the syringe assembly of FIG. 1. FIG. [Figure 3] FIG. 3 is an exploded side view of the syringe assembly. [Figure 4] FIG. 4 is an exploded perspective view of the syringe assembly. [Figure 5] FIG. 5 is a side view in cross section of the syringe assembly. [Figure 6] FIG. 6 is an exploded side view in cross section of the syringe assembly. [Figure 7] FIG. 7 is an enlarged side view in cross section of the adapter. [Figure 8] FIG. 8 is a side view of the syringe assembly during injection. [Figure 8A]FIG. 8A is a side view of the syringe assembly showing a finger applying linear force to penetrate the septum of the vial. [Figure 9] FIG. 9 is a perspective view of a syringe assembly according to a second embodiment. [Figure 10] 10 is a side view of the syringe assembly of FIG. 9. FIG. [Figure 11] FIG. 11 is an exploded view of the syringe assembly of FIG. [Figure 12] 12 is an end view of the adapter of the syringe assembly of FIG. 9. FIG. [Figure 13] 13 is a side view in cross section of the syringe assembly of FIG. 9. FIG. [Figure 14] 14 is a cross-sectional view of the adapter of the syringe assembly of FIG. 9. FIG. [Figure 15] 15 is a cross-sectional view of the syringe assembly of FIG. 9. FIG. [Figure 16] 16 is a bottom perspective view of the adapter of the syringe assembly of FIG. 9; FIG. [Figure 17] FIG. 17 is a side view of the adapter showing deformation of the skin during injection. [Figure 18] FIG. 18 is a perspective view of a syringe assembly according to another embodiment. [Figure 19] 19 is a side view of the syringe assembly of FIG. 18. FIG. [Figure 20] 20 is an exploded perspective view of the syringe assembly of FIG. 18. FIG. [Figure 21] FIG. 21 is an exploded side view of the syringe assembly, showing the adapter in cross section. [Figure 22] 22 is a top view of the adapter of the syringe assembly of FIG. 18. FIG. [Figure 23] 23 is an enlarged side view of the syringe assembly of FIG. 18. FIG. [Figure 24] FIG. 24 is a side view of the syringe assembly showing the needle during insertion into the skin. [Figure 25] FIG. 25 is a side view of a further embodiment of an adapter hub. [Figure 26] 26 is a perspective view of the adapter hub of FIG. 25. FIG. [Figure 27] 27 is a top end view of the adapter hub of FIG. 25. FIG. [Figure 28] 28 is a cross-sectional view of the adapter hub of FIG. 25. FIG. [Figure 29] 29 is a perspective view of the adapter hub of FIG. 25. FIG. [Figure 30] FIG. 30 is an elevational view of a syringe assembly coupled to a vial. DETAILED DESCRIPTION OF THE INVENTION

[0021] The syringe assembly of the present invention refers to a syringe barrel and a needle or cannula for injecting a medication or the like 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 a target injection site. The distal direction is toward the injection end of the syringe assembly, 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.

[0022] The syringe assembly is configured to inject a drug into a patient at a depth selected depending on the drug and the intended depth of penetration. The intradermal layer in adults is generally about 2-3 mm thick, so the depth of intradermal injection ranges up to about 3 mm 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 administered. The subcutaneous region has an average thickness of about 7 mm to about 15 mm. Insulin can be preferably delivered to the subcutaneous region.

[0023] The syringe is suitable for injection methods, such as injecting medications such as insulin into patients. The description of the embodiments should not be considered as limiting the invention. The present disclosure is intended to enable those skilled in the art to implement variations of the invention described without departing from the scope of the invention. Numerical limitations herein in the specification and claims are understood to be qualified by the modifier "about," and minor deviations achieving equivalent results are within the scope of the invention. Features disclosed in connection with one embodiment or 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.

[0024] This disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The embodiments herein may be modified, implemented, or performed in various ways. It is also understood that the phraseology and terminology used herein are for descriptive purposes and should not be regarded as limiting. The use of "including," "comprising," or "having," and variations thereof, herein means the inclusion of additional items in addition to the items listed thereafter and their equivalents. Unless otherwise limited, the terms "connected," "coupled," and "mounted," and variations thereof, herein are used broadly and encompass both direct and indirect connections, couplings, and attachments. Additionally, the terms "connected" and "coupled," and variations thereof, are not limited to physical or mechanical connections or couplings. Furthermore, terms such as "up," "down," "below," and "over" are relative and are used to aid in illustration, but are not limiting. The embodiments are not intended to be mutually exclusive, and features of one embodiment can be combined with other embodiments unless they are mutually exclusive. Terms of degree such as "substantially," "about," and "approximately" are understood by those skilled in the art to refer to a reasonable range around and including a given value, as well as ranges outside the given value, such as the typical range of tolerance associated with the manufacture, assembly, and use of an embodiment. The term "substantially," when referring to a structure or characteristic, includes a characteristic that is mostly or completely present within the structure.

[0025] Referring to the drawings, syringe assembly 10 includes a syringe having a syringe barrel 12 with a proximal end 14 and a distal end 16, and an internal cavity containing a medication. Proximal end 14 receives a movable plunger 18 and a stopper 20 for dispensing the substance contained in syringe barrel 12. Plunger 18 includes a plunger rod and a distal end coupling member for coupling the stopper to the plunger rod. It is understood that plunger 18 includes a stopper during use to expel the contents of the syringe barrel, although the stopper is not shown in certain figures for clarity. As shown in FIGS. 1 and 2, syringe barrel 12 has a flange 22 at its proximal end that forms a finger or hand grip for a user. A dispensed volume indicator 24 is provided on the side of the syringe barrel.

[0026] Referring to FIG. 3 , syringe barrel 12 has a hub 26 at its distal end for supporting a cannula or needle 28. Needle hub 26 extends axially from the distal end of the syringe barrel. In the illustrated embodiment, needle hub 26 has a substantially cylindrical body portion 30 at the distal end of the syringe barrel and a distal portion 32 spaced distally from the syringe barrel and body portion 30. In the illustrated embodiment, hub 26 is integrally formed with syringe barrel 12. Syringe barrel 12 and hub 26 are made of a suitable plastic material and can be integrally formed by a suitable molding process. Hub 26 has an axial passageway, shown in FIGS. 5 and 6 , extending axially for supporting needle 28, which provides a fluid path between the interior cavity of the syringe barrel and the distal injection end of needle 28. Needle 28 is secured to hub 26 by adhesive or other mechanisms known in the art.

[0027] Distal portion 32 of hub 26 extends from cylindrical portion 30 and has a width that is less than the width or diameter of cylindrical portion 30. In the illustrated embodiment, the distal portion is formed by a central portion having an axial passage for supporting needle 28 and radially extending ribs 34 that extend outward from the distal portion. In the illustrated embodiment, three ribs 34 are provided that extend radially outward and axially from cylindrical portion 30. The distal ends of ribs 34 have sloped axial end faces 36 that converge toward the center of the hub and needle. As shown in FIG. 3 , ribs 34 have a radial dimension that is less than the outer diameter of cylindrical portion 30 and less than the outer diameter of syringe barrel 12.

[0028] In the illustrated embodiment, syringe assembly 10 includes a distal end member in the form of an adapter 40 coupled to hub 26. Adapter 40 may be coupled to hub 26 by any suitable mechanism, such as adhesive, a friction fit, or an interference fit. In further embodiments, adapter 40 may be integrally formed with hub 26 by a suitable molding process. In one embodiment, adapter 40 is secured to hub 26 and syringe barrel 12 during manufacture so that the syringe assembly is delivered to the end user as an integral unit.

[0029] The outer needle cover 42 is provided to cover the needle 28 until it is ready for use. In the illustrated embodiment, the outer cover 42 has a substantially cylindrical body 44 with a closed distal end 46 and an open proximal end 48. In the embodiment shown in FIG. 5, the closed distal end 46 has dimensions larger than the outer dimensions of the body 44 to aid in a user's grip of the outer cover. The body 44 has an internal cavity 50 with dimensions configured for mating with the adapter 40. As shown in FIG. 6, the inner surface of the cavity 50 includes a plurality of annular ribs 52 for providing a friction fit with the adapter 40. The outer cover 42 can be made of a flexible or rigid plastic material that can be attached and detached from the adapter 40 by the user. The outer cover 42 is attached to the adapter and covers the needle before and after use to reduce the risk of an accidental needle stick. The outer cover can be removed during use and replaced after use, allowing the used syringe assembly to be disposed of.

[0030] Needle 28 is typically a stainless steel needle or cannula having a lumen and a sharp tip for injecting the contents of the syringe barrel into a patient. Needle 28 can have a gauge appropriate for the intended injection and delivery. Needles can be 30-36 gauge. In one embodiment, needle 28 can be 32-35 gauge. In another embodiment, the needle can be 34 gauge.

[0031] The needle 28 can have an exposed or effective length appropriate for the intended injection to achieve the intended penetration depth and delivery of the drug. The exposed length of the needle 28 extending from the distal end of the adapter 40 can be from about 3.5 mm to about 12.7 mm. In one embodiment, the needle has an exposed length of from about 4.0 mm to about 6.0 mm. In another embodiment, the needle can have an exposed length of from about 4.0 mm to about 4.1 mm. The needle 28 has a length that extends from the cavity of the syringe barrel, through the adapter 40, and has an exposed portion extending from the adapter the desired length to penetrate the skin to a depth selected depending on the drug to be delivered to the patient. The syringe assembly is particularly suitable for needles with short lengths of from about 4.0 mm to about 4.5 mm.

[0032] 5 and 6, adapter 40 is configured to mate with hub 26 of syringe barrel 12 and to provide a surface for contacting a patient's skin during injection to limit the needle penetration depth into the patient's skin. Adapter 40 may be integrally formed with the distal end of the syringe barrel. Adapter 40 has a body 54 for mating with hub 26 and a distal end portion 56. Distal end portion 56 has a distal face and a proximal face for contacting the patient's skin during use.

[0033] The body 54, as shown in FIGS. 5, 6, and 7, has a substantially cylindrical wall with an inner cavity 58 and a proximal end 60. The inner cavity 58 is shaped and configured for coupling to a syringe. In the illustrated embodiment, the outer surface of the body 54 includes longitudinally extending ribs 62 to assist the user in gripping the syringe assembly during use. The inner cavity 58 has a cylindrical inner surface 64 at the body's proximal end, sized to complement the outer diameter of the cylindrical portion 30 of the hub 26. The body 54 can be bonded to the cylindrical portion 30 by adhesive or welding to secure the body 54 to the hub 26. In other embodiments, the body 54 can be coupled to the hub 26 by a friction fit or an interference fit. The cavity 58, as shown in FIG. 6, has a distal end with a tapered surface 66 for receiving the angled distal end 36 of the rib 34. As shown, the cavity 58 has a shape and size that complements the shape and size of the needle hub, providing a secure fit of the adapter to the hub. The needle hub of the syringe may have a different shape and configuration than the illustrated embodiment, and the adapter cavity has a shape and configuration that corresponds to the shape of the particular syringe and needle hub.

[0034] The distal end portion 56 of the adapter 40 extends axially distally from and radially relative to the body 54 to form a radial flange around the syringe barrel. The distal end portion 56 has an inner post 68 and an annular outer portion 70 having an annular or circular shape. The annular outer portion 70 is spaced radially outward from the post 68 to form an annular recess 78. The post 68 extends axially distally from the adapter 40 and the outer portion 70 and is axially oriented. The post 68 in the illustrated embodiment includes a cylindrical sidewall 72, an axial distal end face 74, and an axial passage 76. In the embodiment shown in FIG. 6, the axial distal end face 74 is substantially flat and oriented in a plane substantially perpendicular to the longitudinal axis of the post. The axial passage 76 is aligned with the axial passage of the hub 26 so that the needle 28 extends through the axial passage 76, as shown in FIG. 5. The axial passage 76 has a diameter to receive the needle 28 and stabilizes the needle to reduce the risk of bending during use. As shown in FIG. 6, the axial passage 76 extends from the distal end face 74 to the cavity 58 in the body 54 of the adapter 40. In one embodiment, the needle is not secured to the inner surface of the axial passage.

[0035] The annular outer portion 70 is spaced radially outward from the posts 68 to form an annular recess 78 between the posts 68 and the annular outer portion 70. The annular recess 78 has a radial width for receiving the outer cover 42 such that when the distal face of the adapter is pressed against a patient's skin during an injection, a portion of the skin forms a contour that extends into the recess. The posts 68 have outer dimensions that complement the inner dimensions of the body 44 of the outer cover 42, allowing the outer cover 42 to couple to the posts 68 via a friction fit.

[0036] The annular outer portion 70 has a diameter greater than the diameter of the body 54 to provide a larger distal contact surface than the hub 26. As shown in FIG. 6 , the annular outer portion 70 has distal end faces 80 spaced radially outward from the end faces 74 of the posts 68. The posts 68 have a longitudinal length greater than the longitudinal dimension of the outer portion 70 such that the end faces 74 of the posts 68 are oriented distally from the end faces 80 of the outer portion 70. In one embodiment, the posts 68 protrude distally from the outer portion 70 to provide an axial spacing between the axial end faces 74 of the posts 68 and the axial end face 80 of the outer portion 70, the distance being approximately 1-2 mm. The distal faces of the posts are oriented distal to the distal surface of the annular outer portion to form a substantially convex skin contact surface to control skin stretch and deformation when the distal ends are pressed against the skin.

[0037] In the illustrated embodiment, the end surface 80 of the outer portion 70 is substantially flat and oriented in a plane substantially parallel to the plane of the end surface 74 of the post 68. The outer portion 70 has an annular side surface 82 extending parallel to the longitudinal axis of the adapter 40 and a chamfered, angled surface 84 extending between the side surface 82 and the end surface 80. The chamfered surface 84 may be oriented at an angle of approximately 40° to 50°, preferably approximately 45°, relative to the longitudinal axis of the adapter 40. In one embodiment, the chamfered surface is a substantially flat, angled surface. In the embodiment shown in FIG. 7, the side surface 82 has a rounded shape. In other embodiments, the side surface may be a flat surface oriented parallel to the longitudinal axis of the adapter. In the illustrated embodiment, the lower surface of the distal end portion 56 of the adapter 40 is provided with a plurality of recesses 88 around the periphery of the end portion.

[0038] The outer portion 70 has dimensions for contacting the surface of the skin to control the shape and depth of skin deformation upon needle insertion and to control needle penetration depth. The outer portion 70 can have a diameter and axial length selected to determine the shape and depth of skin deformation when the outer portion contacts the patient's skin. The outer portion 70 defines the adapter's outer dimensions and the adapter's skin-contacting surface. The annular outer portion 70 has a diameter ranging from 10.0 mm to about 30.0 mm. In one embodiment, the outer portion has a diameter of about 10.0 mm to about 20.0 mm. The axial length between the bottom, proximal end, of the side surface 82 and the axial end surface 74 can range from about 2.0 mm to about 6.0 mm. In one embodiment, the combined axial length of the side surface 82 and the chamfered surface 84 is about 3.0 mm to about 5.0 mm.

[0039] The outer portion 70 of the adapter 40 has a proximal surface 88 that extends from the body 54 to the outer edge of the annular outer portion 70. The proximal surface 88 in the illustrated embodiment has a curved, convex shape configured and sized to assist a user in gripping and manipulating the syringe assembly 10. In the illustrated embodiment, the proximal surface includes a plurality of spaced recesses 89 to provide a slip-resistant surface. While the recesses are shown as having a substantially rectangular configuration, other shapes can also be provided. The proximal surface is shaped to form a flange for a user to grip when filling the syringe from a vial. As shown in FIG. 8A , a user can place their index finger 91 and middle finger 93 on opposite sides of the proximal surface of the body 54 while holding the vial in the palm of their hand. The fingers can then apply a substantially linear force to the syringe assembly, which can axially penetrate the septum 95 of the vial 97, allowing the needle to pass through the septum for filling and aspiration. The dimensions of adapter 40 and outer annulus 70 assist the user in positioning the needle parallel to the axis of the septum and vial and applying a linear force to the needle. Applying a linear axial force to the vial and septum forces the needle tip through the septum and the interior of the vial, allowing the syringe to be filled. This linear force reduces the chance of the needle penetrating the septum at an angle that prevents the needle tip from completely passing through the septum, preventing the syringe from being filled. The linear force also reduces the chance of the needle bending. Proximal surface 88 can also be used by the user to apply an insertion force during needle insertion into a patient and to stabilize the syringe during injection by placing a finger on the proximal surface.

[0040] To use the syringe, the outer cover 42 is removed from the tip of the adapter 40, exposing the needle. The syringe can be pre-filled or filled by the user upon aspirating. As shown in FIG. 8, the user can fill the syringe by holding the vial in the palm of their hand, applying an insertion force with their fingers against the proximal side of the adapter, and pulling the syringe toward the vial where the needle penetrates the septum. The needle 28 is introduced into the patient's skin 86 to a depth where the adapter's surface contacts the skin, as shown in FIG. 8. The distal face of the adapter 40 has a width and curvature that deforms the skin surface under typical insertion forces to form an indentation of controlled depth and width, thereby controlling the needle penetration depth to a selected depth. The width of the adapter's distal face distributes the insertion force over a larger area and limits the depth of skin deformation caused by the distal face. As the needle penetrates the skin, the struts 68 of the adapter 40 contact the skin, creating an indentation conforming to the dimensions of the struts. As the insertion force continues, a portion of the skin deforms and stretches into the annular recess until the adapter's annular outer portion 70 contacts the skin. The flat surfaces and angle of the outer side edges of the outer portion create a depression in the skin surface, distributing the insertion force over the skin surface area and limiting the depth of the skin depression, thereby limiting the needle penetration depth.

[0041] Another embodiment of syringe assembly 90 is shown in Figures 9-17. Syringe assembly 90 includes syringe barrel 12, an adapter 92, and a needle cover 42. Because the syringe barrel and needle cover are substantially the same as in the previous embodiment, for clarity and consistency, parts are identified with the same reference numerals.

[0042] As in the previous embodiment, adapter 90 is coupled to hub 28 of syringe barrel 12. Adapter 90 can be coupled to syringe barrel hub 28 by a friction fit, an interference fit, or can be permanently secured by adhesive or welding. Adapter 90 is typically permanently secured to the syringe barrel during manufacture and delivered to the end user as an integrally formed unit. In further embodiments, the adapter can be molded onto or together with the syringe barrel to form an integral assembly.

[0043] 10-16, the adapter 90 is configured to couple to the syringe hub and provide a surface for limiting the penetration depth of the needle 28. As shown in FIG. 10, the adapter 90 has a proximal body 94 and a distal end portion 96. The body 94 has a substantially cylindrical sidewall 96 with an open proximal end 98 that forms an axial passage 100. The axial passage 100 has an inner surface 102 having dimensions complementary to the outer diameter of the cylindrical portion 30 of the hub 26 for coupling the adapter 90 to the syringe barrel. The inner surface 102 of the axial passage converges at the distal end to form a sloped, tapered surface 104. The axial passage 100 converges at the distal end portion 96 to form a passage 106 having a diameter smaller than the diameter of the axial passage 100 but sufficient to allow the needle to pass therethrough, as shown in FIG. 13. In the illustrated embodiment, the needle extends through the adapter 90 and is not secured to the adapter. Axial passage 100 receives the needle to stabilize it and inhibit bending of the needle during use.

[0044] The distal end portion 96 is integrally formed with the body 94 and has a diameter greater than that of the body 94 to define an enlarged skin-contacting surface during injection. An axial passage 106 in the distal end portion 96 extends through a central post 108 that extends axially from the adapter. An annular outer portion 110 surrounds the post 108 and is spaced radially outward to form an annular recess 112. The post 108 has an outer diameter complementary to the inner diameter of the needle cover 42 for connecting the needle cover 42 to the adapter 90. The post 108 as shown has a substantially flat axial surface 118 adjacent the needle 28. The outer peripheral edge of the axial surface 118 is provided with a stepped portion 120 that opens into the annular recess 112.

[0045] The annular outer portion 110 in the illustrated embodiment has a substantially cylindrical side surface 114 oriented substantially parallel to the longitudinal axis of the syringe barrel and adapter. As shown, the side surface 114 is smooth and converges with the body 94, which has a smooth, continuous curvature. The annular outer portion 110 has an axial surface 116 that forms a convex shape, sloping inwardly toward the post 108 in a proximal direction relative to the adapter 92. The axial surface 116 extends from an outer peripheral edge 122 to an inner edge 124 in the annular recess 112. The outer peripheral edge 122 forms the distal surface of the adapter 92 for initial contact with the patient's skin during injection. As shown in FIG. 15 , the axial surface 118 of the post 110 is oriented flush with the distal edge of the outer portion formed by the outer peripheral edge 122.

[0046] In the illustrated embodiment, the outer periphery 122 of the axial surface 116 has a rounded profile extending between the axial surface 116 and the side surface 114. The axial surface 116 has a substantially flat, sloped configuration. A plurality of recesses 126 are formed in the axial surface to assist in deforming the patient's skin during an injection.

[0047] The adapter 92 has a circular configuration with a diameter sufficient to contact the patient's skin to control needle insertion depth. The axial surface 116 of the annular outer portion 110 can have a diameter of about 10.0 mm to about 30.0 mm. In one embodiment, the axial surface 116 of the outer portion has a diameter of about 10.0 mm to about 20.0 mm. The axial spacing between the axial surface 116 of the outer portion 110 and the axial surface 118 of the post 108 can be about 2.0 mm to about 5.0 mm. In one embodiment, the axial spacing between the axial surface 116 of the outer portion 110 and the axial surface 118 of the post 108 can be about 2.0 mm to about 4.0 mm. The needle can have a length and gauge similar to the previous embodiment.

[0048] 10, adapter 92 has a proximal surface 103 with a substantially convex configuration that forms a finger grip for a user. The adapter has a sufficient diameter that allows a user to place their index and middle fingers on opposite sides of proximal surface 103 to apply an insertion force to a vial that allows a needle to penetrate the septum, similar to the way a user would place their index and middle fingers on opposite sides of proximal surface 103 to apply an insertion force to a vial.

[0049] In use, the outer cover is removed, exposing the needle 28 in preparation for injection. The needle 28 penetrates the surface of the patient's skin where the adapter contacts the skin. The outer rim 122 first contacts the skin, creating a depression in the skin. The insertion force of the syringe assembly 90 causes the skin to contact the axial surface of the post and deform into the annular recess 112 and the recess in the axial surface of the adapter, as shown in FIG.

[0050] Another embodiment of syringe assembly 130 is shown in Figures 18-24. Syringe assembly 130 includes syringe barrel 12, adapter 132, and needle cover 42. Because syringe barrel 12 and needle cover 42 are substantially the same as in the previous embodiment, for clarity and consistency, parts are identified with the same reference numerals.

[0051] As in the previous embodiment, adapter 132 is coupled to hub 28 of syringe barrel 12. Adapter 132 can be coupled to hub 28 of the syringe barrel by a friction fit, an interference fit, or can be permanently secured by adhesive or welding. In one embodiment, adapter 132 is permanently secured to the syringe barrel during manufacture and delivered to the end user as an integrally formed unit. In further embodiments, the adapter can be molded onto or together with the syringe barrel to form an integral assembly.

[0052] 20 and 21, adapter 132 is configured to mate with the syringe hub and provide a surface for limiting the penetration depth of needle 28. As shown in FIG. 21, adapter 132 has a proximal body 134 and a distal end portion 136. Body 136 has a substantially cylindrical sidewall 138 with an open proximal end 140 that forms an axial passageway 142. Axial passageway 142 has an inner surface 144 having dimensions complementary to the outer diameter of cylindrical portion 30 of hub 26 for coupling adapter 132 to the syringe barrel. Axial passageway inner surface 144 converges at the distal end to form a sloped tapered surface 146. Axial passageway 142 converges at distal end portion 136 to form a passageway 148 having a diameter smaller than the diameter of axial passageway 142 but sufficient to allow a needle to pass therethrough, as shown in FIG.

[0053] The distal end portion 136 is integrally formed with the body 134 and has a diameter greater than that of the body 134 to define an enlarged skin-contacting surface during injection. The axial passageway 148 in the distal end portion extends through a central post 150 that extends axially from the adapter. An annular outer portion 152 surrounds the post 150 and is spaced radially outward to form an annular recess 154. The post 150 has an outer diameter complementary to the inner diameter of the needle cover 42 to connect the needle cover 42 to the adapter 132. The post 150 as shown has an axial surface 156 with a convex configuration. The side of the post 150 has a substantially cylindrical configuration oriented in a plane parallel to the longitudinal axis of the adapter 132.

[0054] The adapter 132 has a diameter that widens at the distal end and converges at the proximal end. As shown in FIGS. 19 and 21 , the outer surface of the adapter 132 has a proximal side with a plurality of annular recesses 160 around the adapter that form annular ribs 162 to assist the user during injection. The adapter has a diameter on the proximal face sized for gripping by a user. The annular recesses 160 and ribs 162 form finger grips sized to allow a user to place their index and middle fingers on opposite sides of the adapter's proximal face to push the needle through the septum of a vial to fill the syringe in a manner similar to the embodiment shown in FIG. 8A .

[0055] The annular outer portion 154 of the adapter in the embodiment shown in FIG. 21 has a substantially flat distal surface 158 spaced radially outward from the distal surfaces 156 of the posts 150. In the illustrated embodiment, the posts 150 extend axially in a distal direction relative to the annular outer portion 154. As shown in FIG. 21 , the convex axial surfaces 156 of the posts 150 project distally from the axial surface of the annular outer portion 154. In one embodiment, the entire convex axial surface of the posts 150 is oriented distally from the axial surface 158 of the annular outer portion 154 such that a portion of the cylindrical side of the posts 150 extends distally of the axial surface 158 of the annular outer portion 152.

[0056] The distal surface of the adapter 132 has dimensions to provide a skin-contacting surface during injection and to deform the surface of the skin in a controlled manner to limit needle penetration depth. The distal surface of the adapter 132 can have a diameter of about 10.0 mm to about 30.0 mm. In one embodiment, the distal surface of the adapter 132 has a diameter of about 10.0 mm to about 20.0 mm. The post 150 can have a diameter approximately one-third the diameter of the distal surface of the adapter 132. In one embodiment, the post has a diameter of about 3.0 mm to about 6.0 mm. The distal surface of the post can protrude a distance of about 1.0 mm to about 3.0 mm from the distal surface of the annular outer portion. The syringe needle can have a length similar to that of the previous embodiment. The dimensions of the adapter can also be similar to those of the previous embodiment.

[0057] During use, the syringe is prepared for use and the needle penetrates the skin due to an insertion force. The needle penetrates the surface of the skin 164 so that the distal face of the adapter contacts the skin, deforming the surface of the skin and distributing the insertion force over a sufficiently large area to limit the depth of skin deformation. As shown in FIG. 24, the configuration of the distal face of the adapter stretches the skin to assist needle penetration and control the depth of penetration.

[0058] In another embodiment, shown in Figures 25-30, the adapter is in the form of a hub 160 for coupling with the distal end of a syringe. Hub 160 has a similar shape and configuration to the previous embodiment, with a body 162 for coupling with the distal end of a syringe and a distal end 164 having a width greater than the width of body 162. The outer surface of end portion 164 has a conical shape that flares radially outward toward distal end 166. End portion 164, like the previous embodiment, has a diameter to provide a proximal surface area to assist the user in manipulating the syringe.

[0059] 26 and 28, the end portion 162 of the hub 160 has a recessed area 168 surrounded by an annular collar 170 that extends distally from the end portion. The annular collar 170 defines a distal end 166 and has an inner surface 172 that is oriented parallel to the axis of the hub 160.

[0060] The body 162 in the illustrated embodiment has a cavity 174 shaped and configured to mate with the end of a syringe. In the illustrated embodiment, the cavity 174 has an inner cylindrical surface 176 and an end face 178. The body 162 can be mated to a syringe in a manner similar to the previous embodiment. An axial passage 180 extends from the cavity 174 to receive a needle, as in the previous embodiment. The axial passage 180 extends through a post 182. The post 182 has a distal face 184 that is recessed relative to the distal end 166 of the annular collar 170. The end piece 164 has an annular portion 188 spaced radially outward from the post 182 to form an annular recess 186. In the illustrated embodiment, the annular portion 188 forms the distal face of the hub and tapers proximally toward the post 182. As shown in FIGS. 27 and 28 , the annular portion 188 has a plurality of recesses 190 formed therein. The bottom surface of the annular recess 186 includes a plurality of recesses 192, as shown in FIGS.

[0061] FIG. 30 shows a hub 160 coupled to a syringe, similar to the previous embodiment. The recessed area 168 and annular collar 170 are sized to receive the end cap 194 that holds the septum in a vial 196 during syringe filling and aspiration. The collar 170 has an axial length to stabilize the vial 196, as shown in FIG. 30. As shown, the recessed area 168 and distal face stabilize the syringe and needle relative to the vial and assist the user in piercing the septum with the needle along an axis parallel to the axis of the vial 196. The dimensions of the hub can be similar to the previous embodiment. The needle can have a length and gauge similar to the previous embodiment.

[0062] The foregoing 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 as an example and not as a limitation on 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. It is particularly noted that features of different embodiments and claims may be combined with each other unless they are mutually inconsistent. Accordingly, all such modifications are intended to be included within the scope of the present invention as defined by the appended claims and their equivalents.

Claims

1. 1. A syringe assembly comprising: a syringe having a proximal end and a distal end, a needle hub, and a needle extending from the distal end of the needle hub; an adapter coupled to the needle hub, the adapter having an axial passageway for receiving the needle and defining an effective length of the needle, and a distal end surface about the needle for contacting the patient's skin as the needle penetrates the patient's skin and limiting the depth of penetration into the patient's skin, the adapter coupled to the needle hub having an annular proximal surface comprising a curved convex shape dimensioned to form a finger grip for applying a distal force to the syringe assembly; A syringe assembly comprising:

2. The syringe assembly of claim 1 , wherein the adapter is secured to the needle hub.

3. The syringe assembly of claim 1 , wherein the adapter is integrally formed with the hub.

4. The syringe assembly of claim 1 , wherein the adapter has a diameter greater than a width of the syringe.

5. 5. The syringe assembly of claim 4, wherein the adapter comprises a central post having an axial passage for receiving the needle, and an annular outer portion spaced radially outward from the central post, the annular outer portion defining an annular recess therebetween.

6. 6. The syringe assembly of claim 5, wherein the strut has an axial length greater than an axial length of the annular outer portion, such that the strut extends distally relative to the annular outer portion.

7. 7. The syringe assembly of claim 6, wherein the post has a substantially flat distal surface and the annular outer portion has a substantially flat distal surface oriented substantially parallel to the distal surface of the post.

8. 8. The syringe assembly of claim 7, wherein the annular outer portion has a beveled outer edge oriented at an oblique angle relative to the distal surface of the outer portion.

9. 2. The syringe assembly of claim 1, wherein the adapter has a body having an open proximal end for mating with the hub of the syringe and a distal end portion having a diameter larger than that of the body.

10. 6. The syringe assembly of claim 5, wherein the post has a substantially flat distal surface, and the outer portion has a substantially flat distal surface oriented substantially parallel to and coplanar with the distal surface of the post.

11. The syringe assembly of claim 5 , wherein the central post has a convex distal surface.

12. The syringe assembly of claim 11 , wherein the convex distal surface is oriented distally relative to the distal surface of the annular outer portion.

13. 1. A syringe assembly comprising: a syringe having a proximal end and a distal end, a needle hub, and a needle extending from the distal end of the needle hub; an adapter secured to the needle hub, the adapter having an axial passageway for receiving the needle and defining an effective length of the needle, and a distal end surface around the needle for contacting the patient's skin as the needle penetrates the patient's skin and limiting the depth of penetration into the patient's skin, the distal end surface of the adapter comprising a central post around the needle, an annular outer portion spaced radially outward from the post, and an annular recess between the post and the annular outer portion, the adapter secured to the needle hub having an annular proximal surface comprising a curved convex shape dimensioned to form a finger grip; A syringe assembly comprising:

14. 14. The syringe assembly of claim 13, wherein the central post has a convex distal surface about the needle.

15. 15. The syringe assembly of claim 14, wherein the annular outer portion has a substantially flat distal surface.

16. 16. The syringe assembly of claim 15, wherein the distal surface of the central post is oriented distal to the distal surface of the annular outer portion.

17. 14. The syringe assembly of claim 13, wherein the annular outer portion has a distal face that defines a concave distal surface.

18. 18. The syringe assembly of claim 17, wherein the distal surface of the annular outer portion has a slope direction that slopes proximally relative to the adapter and inwardly relative to the annular recess.

19. 19. The syringe assembly of claim 18, wherein the annular outer portion has a periphery defining a distal end of the annular outer portion, and the central post has an axial face oriented coplanar with the plane of the periphery.

20. 20. The syringe assembly of claim 19, wherein the central post has a substantially flat distal surface.

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