WO2023191770A1

WO2023191770A1 - Pen needle assembly and retractable needle shield

Info

Publication number: WO2023191770A1
Application number: PCT/US2022/022255
Authority: WO
Inventors: Sergey Grigoryants; Kelly Gail DUNCAN; Paul CARSE; William Carr
Original assignee: Embecta Corp.
Priority date: 2022-03-29
Filing date: 2022-03-29
Publication date: 2023-10-05

Abstract

A pen needle assembly for a pen needle includes a body, a needle hub, a cannula or needle coupled to the needle hub, a retractable needle shield and where the needle hub is movable from a proximal position in the body to a distal position. The pen needle can have a biasing member between the needle hub and the needle shield to bias the needle shield distally. The needle hub has a needle with a distal end where the needle hub is movable in the body from a proximal position where the distal end of the needle is in a first position and a second position where the distal end of the needle extends distally from the body. The needle shield is movable in the body from a retracted position to an extended position relative to the body and the needle hub.

Description

PEN NEEDLE ASSEMBLY AND RETRACTABLE NEEDLE SHIELD

BACKGROUND

Field of the Invention

[001] The present invention is directed to medical devices for delivering and/or injecting a medication, such an injection into a patient. The device can be a pen needle including a needle hub and a shield with a distal surface where the shield is retractable during use to expose the needle. The needle hub supports the cannula or the needle. The device has a biasing member to bias the needle shield in a distal direction relative to the hub.

Description of the Related Art

[002] A medication pen for delivering self-administered medications generally includes a pen body, which houses a medication compartment. A separate pen needle can 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] Shorter needles, such as 4 mm and 5 mm needles, are adapted to achieve injection to a specified target depth in a subcutaneous region. In one aspect, the needle hub ensures that a needle is inserted to a desired target depth, regardless of the angle at which the user may approach the injection site with the medication pen or delivery device.

[005] 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. However, the edge of the needle hub engages the skin when the cannula is inserted at an angle, interfering with the injection. The slight taper is not functional during an injection, or is only at the edge of the distal face of the needle hub.

[006] 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

[007] The present invention is directed to a medical device for delivering a substance. The medical device is a delivery device, such as an injection device. The injection device can be a pen needle for coupling to an injection pen or other delivery device.

[008] 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 or cannula for introducing the medication to the patient. The needle or cannula can have a proximal end for piercing a septum on the injection pen where the proximal end is covered by the needle hub.

[009] The pen needle assembly in one embodiment includes body forming a housing, needle hub, and a distal needle shield covering at least a portion of the cannula. The distal needle shield moves and/or slides relative to the body and the needle hub between a retracted position to expose the needle and an extended position to cover the needle. The pen needle assembly can have a biasing member that contacts a surface to bias the needle shield in a distal direction.

[0010] The pen needle in one embodiment has a needle hub with a needle or cannula, a body receiving the needle hub where the needle hub is moves within the body and a distal needle shield that moves relative to the needle hub and the body. The distal needle shield can have an integral spring member that contacts a proximal face of the hub to bias the needle shield in a distal direction.

[0011] The needle hub is received in the body that forms a housing of the pen needle assembly. The needle hub is movable axially between a retracted position where the needle is enclosed within the body and an extended position where the needle tip projects from the body during use. After use, the needle hub can be retracted relative to the body to retract the needle into the body.

[0012] The needle shield is movable within the body between a retracted position and an extended position. The needle shield can be movable to an extended distal position by distal movement of the needle hub to an extended position. A spring member between the needle shield and the needle hub allows the needle shield to be retracted relative to the needle hub and the body to expose the needle during use. The needle shield can be moved distally by the spring member to a locked position to cover the needle after use.

[0013] The features of the pen needle can be attained by providing a pen needle having a body having a side wall with a proximal open end and an open distal end, a needle hub having a needle with a distal end and needle shield. The needle hub is movable axially in the body from a proximal position where the distal end of the needle is in a first position and a distal position where the distal end of the needle is exposed from the distal end of the body. The needle shield is movable in the body from a retracted position when the needle hub is in the proximal position in the body to an extended position relative to the body and relative to the needle hub when the needle hub is in the distal position.

[0014] The features of the pen needle are also attained by providing pen needle that includes a body having side wall, and open proximal end, and an open distal end, a needle hub and a needle shield. The needle hub has a needle with a needle tip. The needle hub is received in an inner cavity of the body and movable axially and rotationally in the inner cavity between a proximal retracted position where the needle is exposed when needle hub is in the distal position. The needle shield is movable axially in the body between a retracted position and an extended position. The needle shield is biased distally when the needle hub is in the distal position. When the needle hub is in the distal position, the needle shield is movable from a first extended position to a retracted to expose the needle tip and then move to a second extended and locked position to cover the needle tip.

[0015 ] The features are also provided by a method of dispensing a fluid comprising coupling a needle hub of a pen needle to a delivery device. The pen needle has a body, a needle coupled to the hub, and a needle shield. The coupling of the needle hub to the delivery device moves the needle hub distally relative to the body and moves the needle shield from a retracted position to a distal position relative to said body. The needle shield is moved from the distal position to the retracted position to expose the needle and the fluid is dispensed from said needle. The needle shield is moved distally to a locked position to cover the needle. The needle hub is moved proximally to the retracted position.

[0016] The pen needle in various embodiments can have a convex distal axial surface for shaping the axial face of the sleeve and shape the 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 mm². 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 mm². [0017] 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. [0018] 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

[0019] The follo wing is a brief description of the drawing in which:

[0020] Fig. 1 is a bottom perspective view a pen needle according to one embodiment;

[0021] Fig. 2. is a top perspective view- of the pen needle of Fig. 1;

[0022] Fig. 3 is a cross sectional view- of the pen needle;

[0023] Fig. 4 is an exploded view of the pen needle showing the needle hub and needle shield;

[0024] Fig. 5 is a side view' of the pen needle when attached to the delivery pen;

[0025] Fig. 6 is a perspective view- of the pen needle attached to the delivery pen;

[0026] Fig. 7 is a perspective view' of the pen needle with the shield retracted;

[0027] Fig. 8 is a perspective view of the pen needle after use. and

[0028] Fig. 9 is cross sectional view of the body of the pen needle.

[0029] DETAILED DESCRIPTION OF THE. EMBODIMENTS

[0030] A delivery’ pen or delivery’ device is used herein to refer to a device having a medication compartment, typically containing multiple doses of medication that can be attached to a separate pen needle. The “pen needle” refers to a needle-bearing assembly which can be attached 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. [0031] 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.

[0032] Illis 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 equivalents 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, bottom, 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.

[0033] In one embodiment the delivery device is a pen needle delivery device or injector pen, which typically comprises a dose knob/button, a body and a cap. The body typically includes a threaded end for coupling with a 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. [0034] In standard pen needle injector devices 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 typical iy attached to a standard pen injector housing by a 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 deliver}' device known in the industry so that the pen needle delivery device is not shown in detail. The cannula of the pen needle can be a double-ended cannula beveled and/or sharpened at both ends for coupling to the delivery device and for penetrating the skin of the patient. The cannula has a lumen with a diameter sufficient to inject the medication into the patient.

[0035] The pen needle 10 as shown in the drawings includes a needle hub 12 having a needle 14, a distal needle shield 16 received in a body 18 forming a housing and/or outer shield. The needle hub 12 and needle shield 16 are configured to move and/or slide relative to the body 18 during use.

[0036] The needle hub 12 as shown in Fig. 4 includes a body 20 having a side w-all 22 with an open proximal end 24 and a distal end 26. The open proximal end has a dimension for receiving a delivery device 28, such as a delivery' pen shown in Fig, 5. The delivery device 28 can be a standard delivery pen as known in the art. The inner surface of the side wall 22 has internal threads for coupling with the deliver)'- device 28 in a usual manner of pen needles. The needle 14 has a proximal, non-patient end positioned in the open end of the needle hub 12 for piercing a septum of the delivery device in a known manner.

[0037] The distal end 26 of the body 20 in the embodiment shown has an end face with a concave recess 30. The recess 30 is formed by an annular shaped ridge 31 extending in a distal direction around the perimeter of the distal end. As shown in Fig. 4, the recess has a substantially flat bottom surface and inclined side edges. A post 32 projects from the distal end 26 and from the recess as shown in Fig. 4. The post 32 in the embodiment shown has a substantially flat shape that extends distally. The post 32 has outer side edges 35 extending in an axial direction relative to a center of the needle hub 12. The distal end of the post 32 has a substantially V-shaped recess around the needle 14 and end surfaces 33 that he in a plane substantially perpendicular to the center axis of the needle hub.

[0038] The post 32 and the needle hub have an axial passage for supporting the needle 14 as shown. In one embodiment, the needle 14 is fixed to the needle hub. The needle 14 has a distal end projecting in a distal direction from the needle hub with a length for injecting a medication into a patient. The needle 14 has a proximal end projecting into the inner cavity of the needle hub formed by the sidewall 22 for piercing the septum of the delivery device in a known manner. The proximal end of the needle 14 can be oriented within the open end of the needle hub and spaced a distance from the proximal end of the needle hub to inhibit inadvertent needle stick.

[0039] The side wall 22 of the body 20 of the needle hub 12 has a substantially cylindrical shape with an outer dimension to move and/or slide axially in the inner cavity of the body 18. The side wall 22 includes at least one outwardly projecting detent 34 for mating with a recess forming a groove 48 formed in an inner surface of the body 18. In one embodiment, two detents 34 project outwardly from opposite sides of the side wall 22. The detents 34 can be oriented toward the distal end of the side wall 22 and extend outwardly a distance to engage the inner surface of the body 18.

[0040] The body 18 as shown in Fig, 3 forms a housing and/or outer shield for the pen needle to receive the needle hub 12 and the needle shield 16, The body 18 has a side wall 36 with an open proximal end 38 with a dimension for receiving the end of the delivery' device 28, The side wall 36 has an inner surface 40 at the proximal end 38 having an inner diameter to receive the delivery device. The side wall 36 has a second inner surface 42 distally of the first inner surface 40 with an inner diameter less that the inner diameter of the first inner surface 40. A flange 44 extends radially outward from the side wall 36 at the proximal end. The outer surface of the side wall 36 at the proximal end includes a plurality of grip protrusions 46 to assist the user in manipulating the pen needle and ataching the pen needle to the delivery device.

[0041] The inner surface 42 of the side wall 36 includes a structure for mating with the needle hub to rotate the needle hub during axial movement of the needle hub relative to the body 18. In the embodiment shown in Figs. 3, 5 and 8, the inner surface 42 includes a spiral groove 48 for receiving a respective detent 34 on the needle hub 12. In this manner, axial movement of the needle hub relative to the body 18 produces a rotation of the needle hub in a first direction as the needle hub moves distally and produces a rotation of the needle hub in a second opposite direction as the needle hub moves proximally. In another embodiment, the spiral groove can be formed in the needle hub and an outwardly projecting detent can be provided on the inner surface of the body 18. Other mechanisms can also be used to provide rotation between the needle hub and the body 18 by axial movement of the needle hub relative to the body 18.

[0042] The needle shield 16 shown in Figs. 3 and 4 is configured for moving axially relative to the body 18 and needle hub 12 during use to expose the distal end or tip of the needle 14 during use and to cover the needle tip after use. The needle shield 16 m the embodiment shown has a substantially cylindrical shape with a side wall 50 and a distal end wall 52. The side wall 50 has a proximal end 54 with a flange 56 extending radially outward. The flange 56 has an outer dimension to move and/or slide axially in the body 18. The side wall 50 and the flange 56 have a longitudinal groove forming a track 66 on an inner surface with an inner dimension to receive the outer side edges 35 of the post 32 so that the needle shield 16 can slide axially relative to the post and rotate with the post when the needle hub 12 rotates by moving the needle hub 12 distally relative to the body 18,

[0043] As shown in Fig. 4, the side wall 50 has a locking member formed by cut-outs 60 forming a flexible leg 62. The flexible leg 62 has an outwardly projecting tab 64 for engaging the inner surface of the body 18 and locking the needle shield in an extended position after use. The inner surface 42 of the side wall 36 of the body 18 has a recess 65 for receiving the tab 64 shown in Fig. 3 and locking the needle shield in the extended position when the tab snaps into the recess. The distal end 68 of the side wall 36 of the body 18 has an inwardly extending tip 70 forming the distal open end 72 of the body 18. The tip 70 has a dimension to contact the flange 56 of the needle shield 16 to retain the needle shield in the body 18. As shown in Figs. 5 and 6, the distal open end 72 has a dimension to allow the needle shield 16 to slide axially with respect to the body 18.

[0044] The distal wall 52 of the needle shield 16 has a distal face and forms a contact, surface for contacting the surface of the skin of a patient when injecting a medication to the patient. The axial face of the body 18 cooperates with the distal face of the needle shield to define the skin contact surface. Referring to Figs. 3 and 4 the distal wall 52 has an outer surface formed by an outer annular ring shaped member 74 extending distally and an inner annular ring shaped member 76. The inner ring shaped member 76 has a distal surface oriented distally relative to the outer annular ring shaped member 74. The outer ring shaped member 74 and the inner ring shaped member 76 form an annular recess 78 having a bottom surface extending between the outer ring shaped member and inner ring shaped member. In the embodiment shown, the distal face of the outer ring shaped member 74 and the distal face of the inner ring shaped member 76 have an inclined surface and are oriented to define a continuous radius of curvature having a convex shape to control the deformation of the skin surface and the depth of penetration of the needle during use. In one embodiment, the bottom surface of the recess has a radius of curvature that is the same as the radius of curvature of the distal face of the inner ring shaped member and distal face of the outer ring shaped member.

[0045] The distal wall 52 of the needle shield has a central opening 88 for allowing the needle 14 to extend through and project from the needle shield 16 during use when the needle shield is retracted relative to the needle hub. In one embodiment, a septum 90 shown in Fig. 2 is provided in the opening 88 to maintain a clean and sterile condition of the needle during storage and prior to use. The septum 90 can be pierced by the distal end or tip of the needle when the needle shield is retracted to expose the distal end of the needle. A seal can be provided between the needle shield 16 and the body 18 to maintain the needle 14 clean and sterile during storage. In one embodiment, the seal can be between the outer edge of the needle shield 16 and the inner edge of the opening 12 that can be broken or ruptured when the needle shield 16 moves to the extended positon shown in Fig. 5.

[0046] The pen needle includes a biasing member to bias the needle shield 16 distally relative to the body 18 and distally relative to the needle hub 12, In the embodiment shown, the proximal end of the needle shield 16 includes a spring member 80 extending between the proximal end of the needle shield 16 and the distal end of the needle hub 12, As shown in Fig. 4, the spring member 80 has a spiral configuration with a first end 82 fixed to the proximal end of the needle shield 16 at the flange 56 and a free end 84 with an end surface for engaging the distal face of the needle hub 12, In one embodiment, the free end 84 of the spring member 80 contacts the recess 30 of the needle hub when the needle shield is retracted.

[0047] The pen needle 10 is assembled as shown in Figs. 1 and 2. A removable closure 86 in the form of a peel tab is attached to the open proximal end of the body 18 to seal the proximal end and maintain a clean and sterile condition of the proximal end of the needle 14. The septum 90 and the seal between the needle shield 16 and the body 18 keep the distal end of the needle 14 clean and sterile. In the initial condition, the needle hub 12 is in a retracted position in the body 18 and the needle shield 16 is in a retracted position in the body 18 as shown in Figs. 1, 2 and 3. As shown in Fig. 3, the proximal end of the needle hub 12 is spaced distally of the open proximal end of the body 18 so that the proximal end of the needle 14 is spaced a distance from the open end of the body 18 to reduce the occurrence of needle stick. The detents 34 on the needle hub 12 are oriented in the proximal end of the respective grooves 48. The needle hub is oriented in the body 18 in the initial position so that the distal end of the needle 14 is enclosed in the body 18 and the needle shield.

[0048] The needle shield 16 in the initial position is oriented where the distal end wall 52 of the needle shield 16 is oriented at the distal end of the body 18 as shown in Fig. 3. The spring members 80 are in the extended position so that the needle shield is distal of the distal end of the needle hub 12. The needle hub 12. is oriented toward the open proximal end 38 of the body 18.

[0049] During use, the needle hub 12 is threaded onto a threaded end of the deliver}' device 28 to couple the delivery device to the needle hub 12 where the proximal end of the needle 14 pierces the septum of the delivery device to supply the needle 14 with the medication. As shown in Fig. 5, the rotation of the body 18 of the pen needle in the direction of the arrow relative to the delivery device 28 during attachment of the pen needle to the delivery device rotates the needle hub 12 so that the detents 34 slide in the spiral grooves 48 and move the needle hub 12 and the needle shield 16 from the retracted position shown in Fig. 3 to an extended distal position shown in Figs. 5 and 6. The rotation of the body 18 relati ve to the delivery device moves the needle hub 12 and needle shield 16 in a distal direction by rotation of the needle hub and the connection between the detents 34 and spiral groove 48 in the body 18. The post 32 received in the track 68 rotates the needle shield 16 when the needle hub 12 is rotated and moved in a distal direction with respect to the body 18. As shown in Figs. 5 and 6, the needle hub 12 is moved to a distal position where the distal end of the needle 14 projects from the distal end of the body 18 and the needle shield 16 is in the extended posi tion relative to the body 18 to cover the needle. In the position shown in Fig. 5, the pen needle 10 is in the readyposition for use.

[0050] The needle shield 16 is retracted by pressing the needle shield 16 against the skin of the subject where the needle pierces the septum 90 in the needle shield to expose the distal end of the needle 14. During use, the needle shield of the pen needle is placed against a surface, such as the surface of the skm of the patient, and an insertion force is applied to retract the needle shield 14 to the position shown in Fig. 7. The insertion force is sufficient where the needle 14 can penetrate skin surface of the patient when an injection is to be performed. The needle shield 16 is retracted and the spring member 80 is loaded and compressed against the distal surface of the needle hub 12. The free ends 84 of the spring members slide over the surface of the recess 30 in the distal face of the needle hub as shown in Fig. 7. The free ends 86 are oriented to slide within recess 30 of the needle hub to maintain the free ends 84 in the recess. The post 32 of the needle hub 12 slides in the longitudinal recess 66 or grooves of the needle shield 16 so that the needle shield 16 retracts in a linear path relative to the needle hub 12 and the body 18. The delivery device is then activated to dispense and deliver}' an amount of the medication to the patient.

[0051] After dispensing the substance from the needle 14, the needle is withdrawn from the patient where the spring members 80 bias the needle shield 16 to a second extended distal position relative to the body 18 and needle hub 12 to cover the distal end of the needle 14. In this position, the distal end of the needle is enclosed and covered by the needle shield 16. After use, the pen needle is rotated to unscrew the delivery’ device from the needle hub 12. The rotation of the needle hub by the engagement of the post 32 with the recess 66 by unscrewing the pen needle relative to the delivery device rotates the needle shield 16 to a position where the locking tabs 64 align with the complementing recesses 66 in the inner surface of the side wall of the body 18 where the tabs 64 snap in place to lock the needle shield in the extended position and prevent retracting the needle shield .

[0052] Further rotation of the needle hub by rotating the delivery' device enables the detents 34 to slide from the distal position along the grooves 48 to the proximal end of the grooves to move the needle hub to the original retracted position where the needle shield separates from the needle hub and the needle shield 16 remains in the locked extended position. In this position, the needle 14 is retracted back into the body as in the original state where the distal needle tip is enclosed within the body 18. With the needle hub in the retracted position and the needle shield 16 in the locked position, inadvertent needle stick is avoided.

[0053] The 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.

Claims

1. A pen needle comprising: a body having a side wall with an open proximal end and an open distal end; a needle hub having a needle with a distal end, said needle hub being movable axially in said body from a proximal position where said distal end of said needle is in a first position and a distal position where said distal end of said needle is exposed from said distal end of said body; a needle shield movable in said body from a retracted position when said needle hub is in the proximal position in said body to an extended position relative to said body and relative to said needle hub where said needle shield in the distal position covers said distal end of said needle when said needle hub is in the distal position.

2. The pen needle of claim 1, wherein said distal end of said needle is shielded by said body when said needle hub is in the proximal position.

3. The pen needle of claim 1 , wherein said needle hub is configured to couple to a deliver}' device by a threaded connection.

4. The pen needle of claim 3, wherein rotation of the deliver}' device in a first direction relative to said body moves said needle hub and needle shield from the proximal position to the distal position.

5. The pen needle of claim 4, wherein one of said body or needle hub includes a spiral groove and the other of said body or needle hub includes a detent received in said spiral groove whereby said needle hub rotates relative to said body by axial movement of said needle hub relative to said body.

6. The pen needle of claim 5, wherein said needle hub moves proximally from the distal position by rotation of the delivery device in a second direction opposite said first direction.

7. The pen needle of claim 1, wherein said needle shield is biased distally relative to said needle hub.

8. The pen needle of claim 7, wherein said needle shield includes a spring member having a distal end to engage a distal end of said needle hub.

9. The pen needle shield of claim 8, wherein said needle shield is movable from the extended position when said pen needle is in a ready position to a retracted position to expose the distal end of said needle, and to a second extended position to cover the distal end of said needle, and where said needle shield is locked in the second extended position after use.

10. The pen needle shield of claim 9, wherein needle hub is movable to a retracted position when said needle shield is in the locked position.

11. A pen needle comprising: a body having side wall, and open proximal end, and an open distal end; a needle hub having a needle with a needle tip, said needle hub received in an inner cavity of said body and movable axially and rotationally in said inner cavity between a proximal position to a distal position where said needle extend distally from said body; a needle shield movable axially in said body between a retracted position and an extended position, said needle shield being biased distally when said needle hub is in the distal position; and wherein when said needle hub is in the distal position, said needle shield is movable from a first extended position to a retracted position to expose said needle tip and to a second extended and locked position to cover said needle tip,

12. The pen needle of claim 11, wherein said needle hub is movable proximally when said needle shield is in the second extended and locked position to retract said needle and needle hub relative to the needle shield and body.

13. The pen needle of claim 12, wherein said needle hub is configured to couple to a deliver}' device by a threaded connection and where rotation of the delivery device in a first direction relative to said body moves said needle hub to the distal position.

14. The pen needle of claim 13, wherein an inner surface of said side wall of said body includes a spiral groove and said needle hub includes a detent received in said spiral groove whereby said needle hub moves axially relative to said body by rotation movement of said needle hub relative to said body.

15. The pen needle of claim 11, wherein said needle shield includes a spring member extending proximally from said needle shield and engaging a distal surface of said needle hub.

16. The pen needle of claim 15, wherein said spring member has a spiral configuration with a first end coupled to said needle shield and a free second end for engaging said distal surface of said needle hub.

17. The pen needle of claim 11, wherein said needle hub is oriented distally of said open proximal end of said body when said needle hub is in the proximal position.

18. A method of dispensing a fluid comprising: coupling a needle hub of a pen needle to a delivery device, said pen needle having a body, a needle coupled to said needle hub, and a needle shield, where coupling said needle hub to said deliver}' device moves said needle hub distally relative to said body and moves said needle shield from a retracted position to a distal position relative to said body; moving said needle shield from the distal position to the retracted position to expose a tip of the needle; dispensing the fluid from said needle; moving said needle shield distally to a locked position to cover the needle; and moving the needle hub proximally to the retracted position where the needle is shielded by the body.

19. The method of claim 18, wherein said body has a side wall with an inner surface having spiral groove, and said needle hub has detent engaging said spiral groove, where distal movement of said needle hub relative to said body rotates said needle hub and needle shield.

20. The method of claim 19, wherein said needle shield has a distal end oriented at a distal end of said body when said is in the retracted position, and where said needle is in a retracted position when said needle hub is in the retracted position.

21. The method of claim 20, wherein said distal end of said needle shield is distal of said distal end of said body and said needle hub and needle are in the distal position when said pen needle is in a ready position.

22. The method of claim 21, where said needle shield is in the locked position and the needle hub and needle are in the proximal position after dispensing the fluid.