BACKGROUND

Field of the Invention

[001] The present invention is directed to medical devices for dispensing a medication. The medical device can used for injecting a medication to a patient. The device can be a pen needle for use with an injection pen. The pen needle has a shield, a hub supporting a needle, and a base for coupling with an injection pen to dispensing or delivering a medication.

Description of the Related Art

[002] A medication pen for delivering self-administered medications generally includes a pen body, which houses a medication compartment, and a separate pen needle which may be attached to and detached from the pen body. The pen needle includes a needle hub having a recess on the proximal side for receiving the pen body and a proximal (non-patient end) needle accessing the medication compartment, typically piercing the septum of a medication cartridge in the pen body. The distal patient end of the pen needle includes the needle or cannula that is inserted into the injection site.

[003] Injections may be performed in the intradermal (ID) region, the subcutaneous (SC) region and the intramuscular (IM) region. For many types of injectable medications, including insulin, the SC region is preferred for administering an injection.

[004] Safety needle devices are know that provide a needle shield to cover the needle after use to reduce the risk of needle stick. The devices commonly include one or more spring members to move the needle shield the shielding position. Safety pen needles are known having dual safety features to cover the patient end of the needle and the non-patient end of the needle after use.

[005] The spring members for safety device are often coil to move the shield distally over the needle tip. Other devices use leaf springs that engage one or more surfaces to move the needle shield to the extended position.

[006] In certain prior art pen needles the cannula is supported in an axially positioned post on the needle hub. The post forms a narrow portion extending distally from the relatively wider portion in which the pen body is received. In other pen needles known in the art, a distal face of the needle hub placed against the injection site may have a slight taper at the edge.

[007] While the prior devices are generally suitable for the intended use, there is a continuing need for improved devices for controlling the penetration of a cannula for delivering a drug or medicament.

SUMMARY

[0081 The present invention is directed to a medical device for dispensing a medication, such as an injection device. The injection device can be a pen needle for coupling to an injection pen or other delivery device for dispensing and delivering a medication.

[009] The pen needle in one embodiment has a needle or cannula extending from a distal end of the pen needle with a movable shield covering the needle or cannula that can be retracted to expose the distal end of the needle for delivering the medication. The needle can have a proximal end for piercing a septum on the injection pen or delivery device where the proximal end is covered by a movable base that moves relative to the needle shield to cover the proximal end of the needle.

[0010] The pen needle in one embodiment includes needle hub, a needle shield covering at least a portion of the needle, and a base cooperating with the needle hub and needle shield. The needle shield slides relative to the base between a first position and a second position proximally of the first position. [0011] The pen needle hub assembly in one embodiment has a needle hub with a needle or cannula, a base receiving the needle hub, and a needle shield that moves or slides relative to the base and needle hub. The needle hub is movable from a first position contacting the base to a distal position where the needle hub and needle are spaced distally of the base where the base covers the proximal end of the needle.

[0012] Another feature of the pen needle is a needle shield that moves relative to the base and the needle hub. The needle shield moves to a retracted position relative to the needle hub to expose the needle tip. The needle shield is biased to an extended distal position relative to the base where the needle hub is moved distally relative to the base and the needle tip is received within the needle shield. [0013] The pen needle in one embodiment has a needle shield with a spring member that engages the base to bias the needle shield distally relative to the base. In one embodiment, the spring member is at least one flexible arm that engages the base when the needle shield is retracted and moves the needle shield to an original extended position relative to the base. The spring member can be a flexible arm that contacts the outer surface of the base. The flexible arm is forced outwardly with respect to an outer surface of the base when the needle shield is moved to the retracted position to tension of the flexible arm to an energized state. The tension of the flexible arm on the base moves the needle shield back the original position with respect to the base and the needle hub.

[0014] The features are basically attained by providing by a pen needle comprising a base having an axial passage with a proximal end and a distal end, a needle hub having a proximal end and a distal end, and a needle extending from the distal end of the needle hub, where the proximal end is configured for contacting the distal end of the base. A needle shield has open proximal end receiving the needle hub and the base and a distal end. The needle shield is movable from a first position with respect to the base and needle hub where the needle is received in the needle hub to a second position where the distal end of said needle extends from the distal end of the needle shield, and to a third position where the distal end of the needle is positioned in the needle shield and the base is moved proximally relative to the base where the base covers a proximal end of the needle.

[0015] The features are further attained by providing a pen needle comprising a needle hub having a proximal end, a distal end, and a needle extending from the distal end of the needle hub. A base has a distal surface configured for contacting the proximal end of the needle hub, and an open proximal end for coupling with a delivery device. A needle shield has a side wall, a distal end, and proximal end receiving the base and needle hub. The needle shield is movable from a first position with respect to the base and needle hub where said needle is received in the needle shield to a second position where a distal end of said needle extends from a distal end of said needle shield, and a third position where the distal end of the needle is positioned in the needle shield and the base is moved proximally to cover a proximal end of the needle.

[0016] The features of the pen needle further include a needle hub having a proximal end, distal end, and a needle extending from said distal end of the needle hub. A base has a distal surface configured for contacting the proximal end of the needle hub, and an open proximal end for coupling with a delivery device. A needle shield has a side wall, a distal end, and proximal end receiving the base and needle hub. The needle shield is movable from a first position with respect to the base where the distal end of the needle is within the needle shield and the needle hub is in contact with the base, and a second position where the distal end of the needle extends from the needle shield, and a third position where the distal end of the needle is within the needle shield and the needle hub and the proximal end of the needle are distal to the base. [0017] The features are also attained by providing a method of using a pen needle comprising providing a pen needle having a needle shield, a base received in the needle shield, and a needle hub having a needle extending from a distal side of said needle hub and from a proximal side of said needle hub when said needle shield is in a first position. The method moves the needle shield to a second position in a proximal direction relative to the base where said needle projects from a distal end of said needle shield. The needle hub is moved proximally relative to a distal end of the needle shield to cover a distal end of said needle and move the said needle hub distally relative to said base to a position in the needle shield where a proximal end of the needle is distal of the base.

[0018] The pen needle in various embodiments can have a convex distal axial surface for shaping the axial face of the sleeve and for shaping tire indentation of the surface of the skin during needle insertion and drug delivery. The needle hub can have an axial face with a surface area of about 5-50 mm ² . The surface of the axial face in one embodiment can have a convex configuration with a height of about of 0.3 to 0.7 mm and a surface area of 1-4 mm ² .

[0019] It will be understood that each of the preferred or optional features of the various embodiments may be combined with other features and features described in combination with one or more particular features may also be combined with one or more other features of the other embodiments. [0020] These and other features of the invention will become apparent from the following detailed description of the invention, which in conjunction with the drawings disclose various embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The following is a brief description of the drawing in which:

[0022] Fig. 1 is an exploded view of the pen needle assembly according to one embodiment;

[0023] Fig. 2 is an exploded view showing the pen needle and injection pen;

[0024] Fig. 3 is a perspective view showing the outer cover removed from the pen needle;

[0025] Fig. 4 is a cross section view of the pen needle in the initial position;

[0026] Fig. 5 is a perspective view showing the pen needle during an injection;

[0027] Fig. 6 is a cross sectional view of the pen needle during an injection;

[0028] Fig. 7 is a cross sectional view of the pen needle after the injection;

[0029] Fig. 8 is a cross sectional view of the pen needle in the deployed condition;

[0030] Fig. 9 is a perspective view of the pen needle in the deployed condition; [0031] Fig. 10 is cross sectional view of the pen needle in the deployed condition; and [0032] Fig. 11 is a bottom perspective view of the pen needle in the deployed condition.

[0033] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] A medication pen or delivery device is used herein to refer to a device having a medication compartment, typically containing multiple doses of medication, and a separate pen needle. The phrase “pen needle” refers to a needle-bearing assembly which can be atached to the medication pen body so that a proximal end of the pen needle assembly accesses a medication compartment and a distal end is adapted for insertion into an injection site to perform one or more injections. The terms “needle” and “cannula” are used herein interchangeably to refer to a hollow tubular member having a lumen and a sharpened end for insertion into an injection site on a subject. As used herein, the “distal” direction is in the direction toward the injection site, and the “proximal” direction is the opposite direction. “Axial” means along or parallel to the longitudinal axis of the needle and the “radial” direction is a direction perpendicular to the axial direction.

[0035] Reference is made to embodiments, which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments described herein exemplify, but do not limit, the present invention by referring to the drawings. The exemplary embodiments are presented in separate descriptions, although the individual features and construction of these embodiments can be combined in any number of ways to meet the therapeutic needs of the user.

[0036] 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 are capable of being modified, practiced or carried out in various ways. Also, it will be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equi valents thereof as well as additional items. Unless limited otherwise, the terms "connected," "coupled," and "mounted," and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. In addition, the terms "connected" and "coupled" and variations thereof are not limited to physical or mechanical connections or couplings. Further, terms such as up, down, botom, and top are relative, and are to aid illustration, but are not limiting. The embodiments are not intended to be mutually exclusive so that the features of one embodiment can be combined with other embodiments as long as they do not contradict each other. Terms of degree, such as “substantially”, “about” and “approximately” are understood by those skilled in the art to refer to reasonable ranges around and including the given value and ranges outside the given value, for example, general tolerances associated with manufacturing, assembly, and use of the embodiments. The term “substantially” when referring to a structure or characteristic includes the characteristic that is mostly or entirely present in the structure.

[0037] In one embodiment the delivery device is a pen needle delivery device or injection pen, which typically comprises a dose knob/button, a body and a cap. The body typically includes a threaded end for coupling with pen needle hub. A dose knob/button allows a user to set the dosage of medication to be injected. The body is gripped by the user when injecting medication. The cap is used by the user to securely hold the pen needle device in a shirt pocket or other suitable location and provide cover/protection from accidental needle injury.

[0038] In standard pen needle devices and injection pens the dosing and delivery mechanisms are found within the body and is not described in greater detail here as they are understood by those knowledgeable of the art. A medicament cartridge is typically atached to a standard pen injector housing by known attachment mechanism. The distal movement of a plunger or stopper within the medicament cartridge causes medication to be forced into the reservoir housing. The medicament cartridge is sealed by a septum and punctured by a septum penetrating needle cannula located within a reservoir or housing. Reservoir housing is preferably screwed onto the medicament cartridge although other attachment mechanism can be used. The pen needle delivery device can be a standard pen delivery device known in the industry so that the pen needle delivery device is not shown in detail. The cannula can be a double-ended cannula beveled and sharpened at both ends for coupling to the pen needle assembly and for penetrating the skin of the patient. The cannula has a lumen with a diameter sufficient to inject the medication into the patient.

[0039] Referring to the drawings, a pen needle 10 is configured for coupling to an injection pen or other medication delivery device. The delivery device can be for introducing a medication to a patient, such as insulin. [0040] The pen needle assembly in the embodiment shown, includes an outer cover 12 that fits over a pen needle 10 that includes a needle shield 14, a base 16 received in the needle shield, and a needle hub 18 received in the needle shield. The needle hub 18 includes a needle 20 or cannula with a distal end 22 extending distally from the needle hub and defining a patient end and a proximal end 24 extending proximally and defining a non-patient end. The distal end 2.2 has a sharpened tip for piercing the skin and/or tissue of the patient during use. The proximal end 24 has a sharpened tip to pierce the septum of the injection pen as known in the art.

[0041] The outer cover 12 has a dimension and configuration for receiving the needle shield, base and needle hub during storage and shipping. The needle shield 12 in the embodiment shown has a side wall 26 with an open end 28 for receiving the pen needle 10 and a closed distal end 30. The inner surface of the side wall 26 includes axially extending ribs 32 for mating with the needle shield 14. The open end 28 can include a closure for maintaining sterile conditions until ready for use. The closure can be a peel tab or other closure member suitable for closing the end of the outer cover.

[0042] The needle shield 14 is configured to receive the base 16 and the needle hub 18 in a sliding manner. The needle shield 14 has a side wall 34 with an open proximal end 36 and a distal end wall 38 having an opening 40 for the needle 20 to extend through during use. The side wall 34 has an outer surface with axially extending grooves 42 for cooperating with the ribs 32 in the assembled position. The inner surface of the side wall 34 is provided with axially extending grooves 44 for guiding the needle hub 18. As shows in Fig. 1 and Fig. 4, the proximal end of the side wall 34 includes a recess 46 formed by an inwardly extending tab 48 at. the proximal end where the recess 46 is configured for mating with the base 16.

[0043] The base 16 has a substantially cylindrical shape formed by a side wall 50 having an open proximal end 52 and a distal end formed by a distal wall 54. As shown in Fig. 4, the side wall 50 has an inner surface with internal threads 56 for coupling with complementing threads 58 on the injection pen 60 shown in Fig. 2. The outer surface of the side wall 50 is provided with an outwardly projecting member 62, shown as a lug, on opposite sides and positioned at the proximal end 52. The projecting member 62 has a shape and configuration complementing the recess 46 on the inner surface of the needle shield 14. The outer surface of the projecting member 62 includes a rib 63 projecting radially outward from the projecting member and extending radially across the projecting member. [0044] As shown in Fig. 1, the base 16 has a distai surface 64 forming an inwardly extending ledge and a tower 66 extending distally from the distal surface 64. The tower 66 supports the distal wall 54, which includes an opening 68 having a dimension for the proximal end of the needle 20 to project through. The tower 66 is formed by a side wall 70 spaced radially inward from the side wall 50. An outer surface of the side wall 70 is provided with a projecting detent 72 on opposite sides of the tower as shown in Fig. 1.

[0045] The needle hub 18 is configured for engaging and/or coupling with the base 16 in an initial configuration of the pen needle. The needle hub as shown in Figs. 1 and 4 has a side wall 74 and an end wall 76. A post 78 extends distally from a distal side of the end wall and a post 80 extends proximally from the proximal side of the end wall 76. The post 78 and post 80 has an axially extending opening for receiving and supporting the needle 20. The needle 20 is fixed to the needle hub by coupling the needle to the post 78 and post 80 by an adhesive or other fastening mechanism as known in the art. The needle 20 is fixed to the needle hub 18 so that the distal end 22 of the needle projects distally a distance to provide for injecting a medication to a patient. The proximal end 24 extends in a proximal direction a distance to pierce the septum of the injection pen.

[0046] The side wall 74 extends in a proximal direction toward the base and forms a proximally facing recess 82 with a shape and configuration for receiving the di stal end of the base 16. The detent 72 of the tower 66 of the base 16 has a dimension to engage the inner surface of the side wall 74 to form a friction fit with the needle hub 18. The side wall 74 has a radial outer surface 84 with a plurality of radially extending ribs 86 spaced around the periphery of the side wall. The ribs 86 are oriented and have a dimension to slide in the grooves 42 of the needle shield 14 to guide the needle hub 18 axially in the needle shield and prevent rotation of the needle hub 18 with respect to the needle shield 14. As shown in Fig. 1, the outer surface of the side wall 74 of the needle hub 18 is provided with a recess 88 on opposite sides of the side wall 74 and oriented between the ribs 86.

[0047] In the embodiments of the pen needle, a biasing member is provided to bias the needle shield 14 distally with respect to the base 16. The biasing member in one embodiment is in a relaxed state when the pen needle is in the original ready position. The biasing member is energized by moving the needle shield proximally relative to the base so that the biasing member moves tire needle shield distally relative to the base after use. An example of a biasing member is disclosed in US Patent 9,498,578, which is hereby incorporated by reference in its entirety. [0048] The biasing member in the embodiment shown is a spring member 90 configured to bias the needle shield 14 distally from the base 16. The spring member 90 is the embodiment shown is coupled to the needle shield and has an end configured to engage the base 16 in an energized or loaded state. The spring member 90 is shown as a flexible arm 92 having a first end coupled to the needle shield and a free end 94. In one embodiment, the flexible arm 92 is integrally formed with the needle shield as a one piece unit. The flexible arm 92. has a base end 94 connected to the needle shield 14 and a free end 96 so the flexible arm 92 extends in a proximal direction relative to the needle shield. The flexible arm 92 is oriented in an opening 98 in the side wall 34 of the needle shield 14.

[0049] The flexible arm 92 is able to flex outward with respect the needle shield to a loaded or energized state and spring back to the original relaxed position. The inner surface of the flexible arms 92 includes a coupling member shown as an inwardly projecting member 100. The projecting member 100 is formed with a substantially flat distal face 102 extending in a plane substantially perpendicular to the axis of the needle shield and an inclined proximal face 104.

[0050] The pen needle 10 in the original state is as shown in Figs. 1-4. Referring to Fig. 4, the pen needle in the ready position has the base 16 positioned at the proximal end of the needle shield 14. The rib 63 on the projecting member 62 is received in a complementing recess 46 in the needle shield 14 to retain the base 16 in the needle shield 14 by a snap fit or interference fit. The needle hub 18 is positioned on the distal end of the base 16 where the tower 66 fits in the recess 88 in the needle hub 18. The detent 72 of the tower engages the inner surface of the needle hub to couple the needle hub and base together by a friction fit. As shown in Fig. 4, the proximal end of the needle 20 projects through the opening in the base 16 a distance for piercing a septum on the injection device. The distal end of the needle extends distally and is enclosed by the needle shield. The spring members 90 are in a relaxed state. The free ends of the flexible aims can contact the needle hub to hold the needle hub against the base until ready for use.

[0051] During use, the pen needle is connected to the injection pen as shown in Figs. 2 and 3 by screwing the threaded connections together and removing the outer cover 12 from the needle shield 14. Referring to Figs. 5 and 6, the needle shield 14 is retracted to a second position with respect to the base 16 to expose the distal end of the needle 20 for dispensing the medication. In one embodiment, the needle shield 14 is positioned against the skin surface of the patient and a force is applied to the injection device and the pen needle to simultaneously retract the needle shield with respect to the base and the injection device and introduce the needle into the surface of the skin. As shown in Figs. 5 and 6, during the injection and movement of the needle shield from the initial first position shown in Fig. 4 to the second position shown in Figs. 5 and 6, the base 16 and the needle hub 18 are moved distally with respect to the needle shield 14.

[0052] The retracting movement of the needle shield 14 relative to the base 16 enables the spring members 90 to contact the surface of the projecting member 62 on the base 16 where the spring members 90 deflect outward as shown in Figs. 5 and 6 to an energized state and applying a biasing force against the base. The deflection or bending of the spring members 90 produces an inward biasing force against the outer surface of the projecting members 62 and the base 16. Prior to moving the needle shield with respect to the base, the spring members are in a relaxed rest position. The movement of the needle shield to retracted position energizes the spring members to produce a biasing force toward from the base. The inward force of the spring members 90 against the base produce a force to move the needle shield distally with respect to the base 16. As shown in Figs. 5 and 6, the spring members 90 in the energized state are at an inclined angle relative to the base 16. The angled surfaces and the inward biasing force cause the needle shield 14 to slide distally with respect to the base.

[0053] At the completion of the dispensing of the medication, the needle is withdrawn from the patient where the biasing force of the spring members 90 against the base 16 move the needle shield 14 distally over the base 16 and needle hub 18 as shown in Fig. 7 and 8. In the position shown in Fig. 7, the outer surface of the base 16 is in contact with the end portions of the flexible arms 92 and the projecting member 100 engages the proximal side of the side wall 74 of the needle hub. In this position, the distal end of the needle 20 is retracted into the needle shield 14 so that the distal end of the needle is protected from inadvertent needle stick. The needle shield 14 is then moved by the energized force of the spring members 90 to move the needle shield 14 distally with respect to the base 16 to the position shown in Figs. 8 and 9. The projecting members 100 of the spring members hook onto the proximal face of the needle hub to so that the distal movement of the needle shield 14 relative to the base 16 moves the needle hub distally and separates the needle hub 18 from the base as shown in Fig. 8. The distal movement of the needle shield relative to tire base retracts the proximal end of the needle from the base so that the proximal end of the needle is not accessible through the base. [0054] The needle shield can be manually moved distally relative to the base where the base is positioned in the proximal end of the needle shield as shown in Fig. 8. As shown in Figs. 9 and 10, the needle shield is moved to a third position where the free ends 96 of the flexible arms 92 engage the distal surface 64 of the base to lock the base in a deploy ed position where the base cannot move distally relative to the needle shield to access the proximal end of the needle 20. The needle hub 18 is held in the position distal of the base by a friction fit between the needle shield and the needle hub. As shown in Fig. 11, the needle hub 18 moves distally with respect to the base 16 so that the proximal end of the needle 20 is covered by the base.

[0055] Ihe above description of the preferred embodiments is not to be deemed as limiting the invention, which is defined by the appended claims. The disclosure is intended to enable the artisan of ordinary skill to practice variants of the invention described without departing from the scope of the invention. Numerical limitations herein, in the specification and in the claims, are understood to be limited by the modifier “about,” such that minor departures yielding equivalent results is within the scope of the invention. Features or dependent claim limitations disclosed in connection with one embodiment or independent claim may be combined in another embodiment or with a different independent claim without departing from the scope of the invention.