WO2023091966A1

WO2023091966A1 - Retractable sleeve for pen needle assembly

Info

Publication number: WO2023091966A1
Application number: PCT/US2022/079984
Authority: WO
Inventors: Sergey Grigoryants; Kelly Gail DUNCAN; Paul CARSE; William Carr
Original assignee: Embecta Corp.
Priority date: 2021-11-17
Filing date: 2022-11-16
Publication date: 2023-05-25

Abstract

A pen needle includes a needle hub having a proximal end configured to couple to a delivery device, and a distal end having a biasing member extending in a distal direction, and a needle received in an axial passage of the needle hub. The pen needle can also include a proximal needle shield biased relative to the needle hub and movable between an extended position to cover a proximal end of the needle and a retracted position, and a distal needle shield having a distal end and an open proximal end for sliding relative to the needle hub, the distal needle shield being biased distally relative to the needle hub by the biasing member, the distal needle shield having a retaining member for engaging the biasing member retain the distal needle shield in an extended position to cover the distal end of the needle.

Description

RETRACTABLE SLEEVE FOR PEN NEEDLE ASSEMBLY

Cross-Reference to Related Applications

[001] This application claims the benefit of and priority to U.S. Provisional Application No. 63/280,393 , filed November 17, 2021 , and the content of this application is hereby incorporated herein by reference in its entirety.

Field

[002] The present disclosure is directed to medical devices for injecting a medication to a patient, and in particular, to pen needles with a retractable shield.

Background

[003] 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.

[004] 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.

[005] 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.

[006] In certain current 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 current pen needles, 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.

[007] While current 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

[008] The present disclosure relates to a pen needle including: a needle hub having an axial passage, a proximal end configured to couple to a delivery device, and a distal end having a biasing member extending in a distal direction; a needle received in the axial passage of the needle hub and having a distal end extending from the distal end of the needle hub and a proximal end; a proximal needle shield biased relative to the needle hub and movable between an extended position of the proximal needle shield to cover the proximal end of the needle and a retracted position of the proximal needle shield; and a distal needle shield having a distal end and an open proximal end for sliding relative to the needle hub, the distal needle shield being biased distally relative to the needle hub by the biasing member of the needle hub; the distal needle shield having a retaining member for engaging the biasing member of the needle hub to retain the distal needle shield in an extended position of the distal needle shield to cover the distal end of the needle.

[009] In some embodiments, the present disclosure relates to a pen needle, wherein: the biasing member of the needle hub has a first end fixed to the needle hub and a second end contacting an axial inner surface of the distal needle shield; the second end of the biasing member slides on the axial inner surface of the distal needle shield when the distal needle shield moves between the extended position of the distal needle shield and a retracted position of the distal needle shield; and the biasing member of the needle hub compresses axially when the distal needle shield moves to the retracted position of the distal needle shield. In some embodiments, the present disclosure relates to a pen needle, wherein the retaining member of the distal needle shield includes a detent extending from the axial inner surface of the distal needle shield to engage the second end of the biasing member to lock the distal needle shield in the extended position of the distal needle shield. In some embodiments, the present disclosure relates to a pen needle, wherein: the retaining member includes a detent; the distal needle shield moves from a first extended position of the distal needle shield where the second end of the biasing member is on a first side of the detent so that the distal needle shield can move to the retracted position of the distal needle shield; and the distal needle shield moves from the retracted position of the distal needle shield to a second extended position of the distal needle shield where the second end of the biasing member is on a second side of the detent where the second end of the biasing member contacts the detent to prevent axial movement of the distal needle shield and retain the distal needle shield in the second extended position of the distal needle shield. In some embodiments, the present disclosure relates to a pen needle, wherein the biasing member of the needle hub has a spiral configuration. In some embodiments, the present disclosure relates to a pen needle, wherein the proximal needle shield has a distal surface including a biasing member to bias the proximal needle shield in a proximal direction. In some embodiments, the present disclosure relates to a pen needle, wherein the biasing member of the proximal needle shield has a first end fixed to the distal surface of the proximal needle shield and a second free end to slide on a proximal surface of the needle hub. In some embodiments, the present disclosure relates to a pen needle, wherein the proximal needle shield includes a cam follower contacting a cam surface to rotate the proximal needle shield by axial movement of the proximal needle shield relative to the needle hub. In some embodiments, the present disclosure relates to a pen needle, wherein the proximal needle shield moves from a first extended position of the proximal needle shield to the retracted position of the proximal needle shield and from the retracted position of the proximal needle shield to a second extended position of the proximal needle shield, and where the cam surface prevents axial movement of the proximal needle shield when the proximal needle shield is in the second extended position of the proximal needle shield. In some embodiments, the present disclosure relates to a pen needle, wherein the biasing member of the proximal needle shield has a spiral configuration.

[0010] The present disclosure relates to a pen needle including: a needle hub having a side wall with an open proximal end, a distal end wall having a biasing member with a first end fixed to the distal end wall and a second end spaced distally from the first end, and a collar spaced radially inward from the side wall and having a proximal end configured for coupling to a delivery device; a needle having a distal end extending from the distal end wall of the needle hub and a proximal end; a proximal needle shield biased relative to the needle hub and moveable between a first extended position of the proximal needle shield to cover the proximal end of the needle, a retracted position of the proximal needle shield, and a second extended position of the proximal needle shield; and a distal needle shield having a distal end and a proximal end for sliding relative to the needle hub, the distal needle shield biased distally relative to the needle hub by the biasing member of the needle hub, the distal needle shield having a retaining member to retain the distal needle shield in an extended position of the distal needle shield to cover the distal end of the needle.

[0011] In some embodiments, the present disclosure relates to a pen needle, wherein the retaining member of the distal needle shield includes a detent on an inner surface of the distal needle shield, and where the second end of the biasing member contacts the detent to prevent axial movement of the distal needle shield. In some embodiments, the present disclosure relates to a pen needle, wherein the biasing member of the needle hub has a spiral configuration. In some embodiments, the present disclosure relates to a pen needle, wherein the proximal needle shield has a distal surface including a biasing member to bias the proximal needle shield in a proximal direction. In some embodiments, the present disclosure relates to a pen needle, wherein the biasing member of the proximal needle shield has a first end fixed to the distal surface of the proximal needle shield and a second free end to slide on a proximal surface of the needle hub. In some embodiments, the present disclosure relates to a pen needle, where the proximal needle shield includes a cam follower contacting a cam surface to rotate the proximal needle shield by axial movement of the proximal needle shield relative to the needle hub. In some embodiments, the present disclosure relates to a pen needle, wherein the proximal needle shield moves from the first extended position of the proximal needle shield to the retracted position of the proximal needle shield and from the retracted position of the proximal needle shield to the second extended position of the proximal needle shield, and where the cam surface prevents axial movement of the proximal needle shield when the proximal needle shield is in the second extended position of the proximal needle shield.

[0012] The present disclosure relates to a pen needle including: a needle hub configured to couple to a delivery device and having an axial passage, a proximal end, and a distal end having a biasing member extending in a distal direction; a needle received in the axial passage of the needle hub and having a distal end extending from the distal end of the needle hub and a proximal end; a proximal needle shield movable within the needle hub between an extended position of the proximal needle shield to cover the proximal end of the needle and a retracted position of the proximal needle shield, the proximal needle shield having a biasing member extending from a distal side of the proximal needle shield for contacting a proximal side of the needle hub for biasing the proximal needle shield; and a distal needle shield having a distal end and an open proximal end for sliding relative to the needle hub, the distal needle shield being biased distally relative to the needle hub by the biasing member of the needle hub, the distal needle shield having a locking member for engaging the biasing member of the needle hub to lock the distal needle shield in an extended position of the distal needle shield to cover the distal end of the needle.

[0013] In some embodiments, the present disclosure relates to a pen needle, wherein the proximal needle shield includes a cam follower contacting a cam surface on an inner surface of the needle hub to rotate the proximal needle shield by axial movement of the proximal needle shield relative to the needle hub. In some embodiments, the present disclosure relates to a pen needle, wherein the proximal needle shield moves from a first extended position of the proximal needle shield to the retracted position of the proximal needle shield and from the retracted position of the proximal needle shield to a second extended position of the proximal needle shield, and where the cam surface prevents axial movement of the proximal needle shield when the proximal needle shield is in the second extended position of the proximal needle shield. In some embodiments, the present disclosure relates to a pen needle, wherein the biasing member of the needle hub has a spiral configuration with a first end fixed to the needle hub and a second end contacting an axial inner surface of the distal needle shield, wherein the second end of the biasing member of the needle hub slides on the axial inner surface of the distal needle shield when the distal needle shield moves between the extended position of the distal needle shield and a retracted position of the distal needle shield, and where the biasing member of the needle hub compresses axially when the distal needle shield moves to the retracted position of the distal needle shield. In some embodiments, the present disclosure relates to a pen needle, wherein: the locking member includes a detent; the distal needle shield moves from a first extended position of the distal needle shield where a second end of the biasing member of the needle hub is on a first side of the detent so that the distal needle shield can move to a retracted position of the distal needle shield; and the distal needle shield moves to a second extended position of the distal needle shield where the second end of the biasing member of the needle hub is on a second side of the detent where the second end of the biasing member of the needle hub contacts the detent to prevent axial movement of the distal needle shield and retain the distal needle shield in the second extended position of the distal needle shield.

[0014] The present disclosure relates to an injection system, including: a delivery device including a supply of medication; and a pen needle, including: a needle hub having an axial passage, a proximal end configured to couple to the delivery device, and a distal end having a biasing member extending in a distal direction; a needle received in the axial passage of the needle hub and having a distal end extending from the distal end of the needle hub and a proximal end; a proximal needle shield biased relative to the needle hub and movable between an extended position of the proximal needle shield to cover the proximal end of the needle and a retracted position of the proximal needle shield; and a distal needle shield having a distal end and an open proximal end for sliding relative to the needle hub, the distal needle shield being biased distally relative to the needle hub by the biasing member of the needle hub; the distal needle shield having a retaining member for engaging the biasing member of the needle hub to retain the distal needle shield in an extended position of the distal needle shield to cover the distal end of the needle.

[0015] In some embodiments, the present disclosure relates to an injection system, wherein: the biasing member of the needle hub has a first end fixed to the needle hub and a second end contacting an axial inner surface of the distal needle shield; the second end of the biasing member slides on the axial inner surface of the distal needle shield when the distal needle shield moves between the extended position of the distal needle shield and a retracted position of the distal needle shield; and the biasing member of the needle hub compresses axially when the distal needle shield moves to the retracted position of the distal needle shield. In some embodiments, the present disclosure relates to an injection system, wherein the retaining member of the distal needle shield includes a detent extending from the axial inner surface of the distal needle shield to engage the second end of the biasing member to lock the distal needle shield in the extended position of the distal needle shield. In some embodiments, the present disclosure relates to an injection system, wherein: the retaining member includes a detent; the distal needle shield moves from a first extended position of the distal needle shield where the second end of the biasing member is on a first side of the detent so that the distal needle shield can move to the retracted position of the distal needle shield; and the distal needle shield moves from the retracted position of the distal needle shield to a second extended position of the distal needle shield where the second end of the biasing member is on a second side of the detent where the second end of the biasing member contacts the detent to prevent axial movement of the distal needle shield and retain the distal needle shield in the second extended position of the distal needle shield. In some embodiments, the present disclosure relates to an injection system, wherein the biasing member of the needle hub has a spiral configuration. In some embodiments, the present disclosure relates to an injection system, wherein the proximal needle shield has a distal surface including a biasing member to bias the proximal needle shield in a proximal direction. In some embodiments, the present disclosure relates to an injection system, wherein the biasing member of the proximal needle shield has a first end fixed to the distal surface of the proximal needle shield and a second free end to slide on a proximal surface of the needle hub. In some embodiments, the present disclosure relates to an injection system, wherein the proximal needle shield includes a cam follower contacting a cam surface to rotate the proximal needle shield by axial movement of the proximal needle shield relative to the needle hub. In some embodiments, the present disclosure relates to an injection system, wherein the proximal needle shield moves from a first extended position of the proximal needle shield to the retracted position of the proximal needle shield and from the retracted position of the proximal needle shield to a second extended position of the proximal needle shield, and where the cam surface prevents axial movement of the proximal needle shield when the proximal needle shield is in the second extended position of the proximal needle shield. In some embodiments, the present disclosure relates to an injection system, wherein the biasing member of the proximal needle shield has a spiral configuration.

[0016] The present disclosure relates to an injection system, including: a delivery device including a supply of medication; and the pen needle of any one of the previous embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The presently disclosed embodiments will be further explained with reference to the attached drawings, wherein like structures are referred to by like numerals throughout the several views. The drawings shown are not necessarily to scale, with emphasis instead generally being placed upon illustrating the principles of the presently disclosed embodiments.

[0018] Fig. 1 is a side view a pen needle according to some embodiments;

[0019] Fig. 2 is a cross sectional view of the pen needle of Fig. 1;

[0020] Fig. 3 is a bottom perspective view of the pen needle;

[0021] Fig. 4 is an exploded view of the pen needle;

[0022] Fig. 5 is a cross sectional view of the side wall and base of the needle hub of the pen needle;

[0023] Fig. 6 is a side view of the base of the needle hub;

[0024] Fig. 7 is a top perspective view of the base of the needle hub;

[0025] Fig. 8 is a perspective view of the side wall of the needle hub;

[0026] Fig. 9 is a cross sectional view of the side wall of the needle hub;

[0027] Fig. 10 is a perspective view of the proximal needle shield;

[0028] Fig. 11 is a side view of the proximal needle shield;

[0029] Fig. 12 is a cross sectional view of the proximal needle shield; [0030] Fig. 13 is top perspective view of the body of the needle hub;

[0031] Fig. 14 is a bottom perspective view of the body of the needle hub;

[0032] Fig. 15 is a cross sectional view of the body of the needle hub;

[0033] Fig. 16 is a top view of the body of the needle hub;

[0034] Fig. 17 is a perspective side view of the distal needle shield;

[0035] Fig. 18 is bottom perspective view of the distal needle shield;

[0036] Fig. 19 is a cross sectional side view of the distal needle shield; and

[0037] Fig. 20 is an exploded view of an example delivery device according to some embodiments.

[0038] While the above-identified drawings set forth presently disclosed embodiments, other embodiments are also contemplated, as noted in the discussion. The present disclosure presents illustrative embodiments by way of representation and not limitation. Numerous other modifications and embodiments can be devised by those skilled in the art which fall within the scope and spirit of the principles of the presently disclosed embodiments.

DETAILED DESCRIPTION

[0039] 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 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.

[0040] 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 disclosure 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.

[0041] 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 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.

[0042] The present disclosure is directed to a medical device such as an injection device. The injection device can be a pen needle for coupling to an injection pen or other delivery device. In some embodiments, the device can be a pen needle and a needle hub. The pen needle can have a shield with patient-contacting surface or skin shaping surface, a hub supporting a cannula or the needle, a distal needle shield movable on the hub to cover the distal end of the needle and a proximal needle shield to cover the proximal end of the needle. The needle hub can have a biasing member to bias the distal needle shield relative to the hub. The proximal needle shield can have a biasing member to bias the proximal needle shield relative to the hub. The pen needle hub can be installed on a medication pen to administer medications to the patient.

[0043] The pen needle, in some embodiments, 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 introducing the medication to the patient. The needle can have a proximal end for piercing a septum on the injection pen where the proximal end is covered by a retractable shield on the needle hub that retracts when the needle hub is attached to the injection pen. [0044] The pen needle, in some embodiments, includes a needle hub, a distal needle shield covering at least a portion of the needle, and a base receiving the needle hub. The distal needle shield moves or slides on the base between an extended first position and a retracted second position proximally of the first position. The needle hub can have a biasing member that contacts an inner surface of the distal needle shield.

[0045] The pen needle, in some embodiments, has a needle hub with a needle or cannula, a base receiving the needle hub and a proximal needle shield that moves relative to the hub. The proximal needle shield can have a biasing member that contacts a proximal face of the hub.

[0046] In some embodiments, the features of the pen needle are provided by a needle hub having an axial passage with a proximal end configured for coupling to a delivery device and a distal end having a biasing member extending in a distal direction. A needle is received in the axial passage of the needle hub and has a distal end extending from the distal end of the needle hub and a proximal end extending from the proximal end of the needle hub. A proximal needle shield is biased relative to the needle hub and movable between an extended position to cover the proximal end of the needle and a retracted position. A distal needle shield has a distal end and an open proximal end for sliding relative to the needle hub, where the distal needle shield is biased distally relative to the needle hub by the biasing member of the needle hub. The distal needle shield has a locking member for engaging the biasing member to lock the distal needle shield in an extended position to cover the distal end of the needle.

[0047] The features are further attained, in some embodiments, by providing a pen needle comprising a needle hub having a side wall with an open proximal end, a distal end having a biasing member with a first end fixed to said distal end and a second end spaced distally from the first end. A collar is spaced radially inward from the side wall and has a proximal end configured for coupling to a delivery device. A needle having a distal end extends from the distal end of the needle hub and a proximal end extending from the proximal end of the needle hub. A proximal needle shield is biased relative to the needle hub and moveable between a first extended position to cover the proximal end of the needle, a retracted position, and a second extended position. A distal needle shield has a distal end and a proximal end for sliding on the needle hub. The distal needle shield is biased distally relative to the needle hub by the biasing member of the needle hub. The distal needle shield has an engagement member to lock the distal needle shield in a second extended position to cover the distal end of the needle.

[0048] The pen needle, in some 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.

[0049] 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. [0050] These and other features of the present disclosure will become apparent from the following detailed description of the present concept, which in conjunction with the drawings disclose various embodiments of the present concept.

[0051] In some embodiments, 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 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 may be 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.

[0052] In standard pen needle injector devices the dosing and delivery mechanisms are found within the body and are not described in greater detail here as they are understood by those knowledgeable of the art. A medicament cartridge is typically attached 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. In some embodiments, the reservoir housing may be preferably screwed onto the medicament cartridge although other attachment mechanism can be used. In some embodiments, 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. [0053] Referring to Fig. 20, a delivery device 200 is depicted according to some embodiments. In some embodiments, the delivery device 200 may be disposable. In some embodiments, the delivery device 200 may include an outer sleeve 213. In some embodiments, the outer sleeve 213 may contain at least some of the driving mechanisms of the delivery device 200 within. In some embodiments, the outer sleeve 213 may contain medication supply to be administered to a patient. In some embodiments, the outer sleeve 213 may provide a gripping surface for a user to grip when administering medication to a patient. In some embodiments, the delivery device 200 includes a dose knob 224 positioned at a proximal end 231 of the outer sleeve 213. The dose knob 224 may be rotatable with respect to the outer sleeve 213 of the delivery device 200. In some embodiments, the user may rotate the dose knob 224 to selectively set a desired volume of a dose of medication to be injected to a patient. In some embodiments, rotation of the dose knob 224 in a first direction may axially translate the dose knob 224 away from the proximal end 231 of the outer sleeve 213, thereby increasing the volume of a dose of medication to be administered with the delivery device 200. In some embodiments, rotation of the dose knob 224 in a second direction may axially translate the dose knob 224 toward the proximal end 231 of the outer sleeve 213, thereby decreasing the volume of a dose of medication to be administered with the delivery device 200. In some embodiments, a button 240 may be coupled to a proximal end of the dose knob 224. A user may apply an axial force to the button 240 to depress the button 240 and dose knob 224 axially toward the proximal end 231 of the outer sleeve 213, thereby activating the driving mechanism to administer a dose of medication from the delivery device 200.

[0054] The driving and delivery mechanisms of the delivery device 200 should be understood by a person having ordinary skill in the art and are, therefore, not discussed in detail herein. Generally, however, depression of the button 240 and dose knob 224 in the distal direction injects the dosed medication via a lead screw 207 and a plunger 215 through a medicament cartridge 212, which is attached to the delivery device 200 through a lower housing 217. The distal movement of the plunger 215 within the medicament cartridge 212 causes medication to be forced into a needle 14 (Fig. 4) of the pen needle 10 (Fig. 4). The medicament cartridge 212 may be sealed by a septum 216, which may be punctured by the needle 14 (Fig. 4) located within the pen needle 10 (Fig. 4). In some embodiments, the pen needle 10 (Fig. 1) may be screwed onto the lower housing 217, although other attachment means may be used. It should be appreciated that the foregoing description is merely one representative example of the delivery device 200, and other designs for the delivery device 200 are contemplated herein.

[0055] A pen needle is discussed with respect to Figs. 1-19. Fig. 1 is a side view a pen needle according to some embodiments. Fig. 2 is a cross sectional view of the pen needle. Fig. 3 is a bottom perspective view of the pen needle. Fig. 4 is an exploded view of the pen needle. Fig. 5 is a cross sectional view of the side wall and base of the needle hub of the pen needle. Fig. 6 is a side view of the base of the needle hub. Fig. 7 is a top perspective view of the base of the needle hub. Fig. 8 is a perspective view of the side wall of the needle hub. Fig. 9 is a cross sectional view of the side wall of the needle hub. Fig. 10 is a perspective view of the proximal needle shield. Fig. 11 is a side view of the proximal needle shield. Fig. 12 is a cross sectional view of the proximal needle shield. Fig. 13 is top perspective view of the body of the needle hub. Fig. 14 is a bottom perspective view of the body of the needle hub. Fig. 15 is a cross sectional view of the body of the needle hub. Fig. 16 is a top view of the body of the needle hub. Fig. 17 is a perspective side view of the distal needle shield. Fig. 18 is bottom perspective view of the distal needle shield. Fig. 19 is a cross sectional side view of the distal needle shield.

[0056] Referring now to Figs. 1-4, a pen needle 10 is depicted. In some embodiments, the pen needle 10 includes a needle hub 12 having a needle 14, a distal needle shield 16, and a proximal needle shield 18. In some embodiments, the distal needle shield 16 is configured for moving axially to expose a distal end 20 of the needle 14 during use and to cover the needle 14 after use. In some embodiments, the proximal needle shield 18 is configured to move to a retracted position relative to the needle hub 12 when the needle hub 12 is attached to the delivery device so that a proximal end 22 of the needle 14 can penetrate a septum on the delivery device to supply the medication. The proximal needle shield 18 can move to a locked extended position after use to cover or block the proximal end 22 the needle 14 after use.

[0057] The needle hub 12 of the pen needle 10 as shown in Figs. 2 and 4 is configured to support the needle 14. In some embodiments, the needle 14 extends through an axial passage of the needle hub 12 and is fixed to the needle hub 12 by an adhesive or other attachment mechanism. In some embodiments, the distal end 20 of the needle 14 projects from the distal end of the needle hub 12 a distance for injecting a medication into a patient. In some embodiments, the proximal end 22 projects from a proximal end of the needle hub 12 a distance for piercing a septum of the delivery device for supplying the medication to the needle and to the patient.

[0058] In some embodiments, the needle hub 12 can be formed as a one-piece unitary member or as separate parts that can be assembled to form the needle hub 12. In the embodiment shown, the needle hub 12 is formed as separate parts for ease of manufacturing where the parts can be assembled prior to delivery to the end user. The parts of the needle hub 12 may be coupled together by suitable attachment mechanisms, such as an adhesive, welding, snap fit, or interference fit. In some embodiments, the needle hub 12 includes a body 24, a side wall 26 in the form of a sleeve coupled to the body 24, and a base 28 attached to the side wall 26. In some embodiments, the body 24 forms a distal end 30 of the needle hub 12 and the base 28 forms a proximal end 32 of the needle hub 12.

[0059] Referring now to Figs. 2, 4, and 15, in some embodiments, the body 24 has a substantially cylindrical outer side wall 34 and a distal end wall 36 having a post 38 extending in a distal direction for supporting the needle 14. In some embodiments, a collar 40 extends in a proximal direction from a proximal side of the end wall 36. In some embodiments, the collar 40 has an inner surface with internal threads 42 for coupling with a threaded connection of the delivery device. In some embodiments, the collar 40 is spaced radially inward from the side wall 34 to form an annular space 44. In some embodiments, the outer surface of the side wall 34 includes at least one and typically at least two lugs 46 for mating with the side wall 26 of the needle hub.

[0060] In some embodiments, the end wall 36 of the body 24 of the needle hub 12 has a biasing member 48 to bias the distal needle shield 16 in a distal direction relative to the needle hub 12 and the body 24. The biasing member 48, in some embodiments, is a spring member that can extend between the needle hub 12 and an inner surface ofthe distal needle shield 16. In some embodiments, the biasing member 48 has a first proximal end 50 fixed to the end wall 36 and has a spiral shape extending to a second free end 52. In some embodiments, two biasing members 48 of the body 24 extend in a distal direction in a spiral manner to contact the inner surface of the distal needle shield 16. In some embodiments, the biasing members 48 are axially compressible relative to the end wall 36 so the free ends 52 move toward the end wall 36 in a compressed or tensioned state and spring back to the original configuration to bias the distal needle shield 16 to the extended position to cover the distal end 20 of the needle 14. In some embodiments, the biasing members 48 are made of a resilient plastic that can bend and spring back to the original configuration. In some embodiments, the biasing member 48 is integrally formed with the body 24 ofthe needle hub 12. In some embodiments, the biasing member 48 can be a separate member with one end (i.e. the first proximal end 50) fixed to the distal face of the end wall 36 of the body 24 of the needle hub 12.

[0061] Referring now to Figs. 4, 5, 8, and 9, the side wall 26 of the needle hub 12 is depicted. In some embodiments, the side wall 26 of the needle hub 12 is a separate member and is coupled or attached to the body 24 of the needle hub 12 by an adhesive or other suitable mechanism. In some embodiments, the side wall 26 has a substantially cylindrical configuration with a distal end 54 and a proximal end 56. In some embodiments, the distal end 54 includes recesses 59 for receiving a respective lug 46 (Fig. 15) of the body 24. In some embodiments, the proximal end 56 includes proximally extending lugs 58 for mating with a corresponding recess in the base 28.

[0062] Referring to Figs. 6 and 7, the base 28 of the needle hub 12 is depicted. In some embodiments, the base 28 has a cylindrical wall 60 with an open proximal end and a flange 62 extending radially outward from the wall 60. In some embodiments, the distal end of the wall 60 includes recesses 64 for mating with a respective lug 58 (Figs. 8 and 9) of the side wall 26 (Figs. 8 and 9). In some embodiments, the base 28 and side wall 26 (Figs. 8 and 9) are coupled together. In some embodiments, the side wall 26 is coupled to the base 28, as shown in Fig. 5, to at least partially form the needle hub 12.

[0063] Referring now to Fig. 5, a cross section of the side wall 26 coupled to the base 28 is depicted. In some embodiments, the inner surface of the side wall 26 and the base 28 form recesses 66. In some embodiments, the recesses 66 form a cam surface for the proximal needle shield 18 (Fig. 4). In some embodiments, each recess 66 includes a first cam track 68 formed by an inclined surface 70 of the base 28 and an inclined surface 72 on the inner surface of the side wall 26. In some embodiments, the first cam track 68 extends from a first recess 74 in the base 28 and extends at an incline with respect to the axis of the needle hub 12 toward the distal end 54 of the side wall 26. In some embodiments, the distal end of the first cam track 68 terminates in an axially extending recess 76 in the inner surface of the side wall 26. In some embodiments, a second cam track 78 extends from the recess 76 toward the base 28 and is formed by an inclined cam surface 80 of the base 28 and an inclined cam surface of the 82 of the side wall 26. In some embodiments, the second cam track 78 terminates at a recess 79 formed between a second recess 77 (Fig. 7) in the base 28 and a proximally facing surface 84 of the side wall 26. In some embodiments, as shown in Fig. 5, the distal surfaces of the cam tracks 68, 78 are formed in the side wall 26 and the proximal surfaces of the cam tracks 68, 78 are formed on the base 28. [0064] Referring now to Figs. 10-12, the proximal needle shield 18 is depicted. In some embodiments, the proximal needle shield 18 has a cylindrical body 86 with a distal surface 88 and a proximal end 90. In some embodiments, the proximal end 90 has an opening 92 with a dimension to receive the end of the delivery device when the delivery device is connected to the pen needle 10 (Fig. 1). In some embodiments, the body 86 includes an inner collar 94 defining the opening 92 of the proximal needle shield 18. In some embodiments, the outer surface of the body 86 has lugs forming cam followers 96 projecting radially outward and oriented to slide within a respective recess 66 (Fig. 5) having the cam surfaces of the side wall 26 (Fig. 5) and base 28 (Fig. 5).

[0065] In some embodiments, the distal surface 88 of the body 86 of the proximal needle shield 18 includes a biasing member 98 for biasing the proximal needle shield 18 in a proximal direction relative to the needle hub 12 (Fig. 4). The biasing member 98, in some embodiments, is a resilient spring having a spiral shape with a first end 100 fixed to the body 86 and a second free end 102 extending distally toward the proximal surface of the body 24 (Fig. 4) of the needle hub 12 (Fig. 4). In some embodiments, as shown in Fig. 10, two biasing members 98 spiral in the distal direction toward the body 24 (Fig. 4) of the needle hub 12 (Fig. 4). In some embodiments, the biasing members 98 may be made of a resilient plastic material to spring to a compressed state and spring back to the original configuration.

[0066] Referring to Figs. 17-19, the distal needle shield 16 is depicted. In some embodiments, the distal needle shield 16 has a side wall 104, a distal end wall 106, and an open proximal end 108. The distal end wall 106, in some embodiments, extends inwardly from the outer edge of the side wall 104 to form a shoulder. In some embodiments, a tower 110 extends distally from the end wall 106 and has an outer dimension less than an outer dimension of the side wall 104. In some embodiments, the tower 110 has a distal patient-facing surface 112 formed by an outer ring 114, an inner ring 116, and an annular recess 118 between the inner ring 116 and the outer ring 114. In some embodiments, the inner ring 116 is spaced axially from the outer ring 114 to form a convex skin contact surface to control the deforming of the indentation of the skin to control the depth of penetration of the needle 14 (Fig. 4) during use.

[0067] In some embodiments, the inner surface of the end wall 106 includes a retaining or locking member shown as a detent 120 for each of the biasing member 48 (Fig. 15) of the needle hub 12 (Fig. 15). In some embodiments, the detent 120 has an inclined surface 122 to enable the free end 52 (Fig. 15) of the biasing member 48 (Fig. 15) to slide over the detent 120 and a flat surface 124 extending in an axial direction and oriented on an opposite side of the inclined surface 122. In some embodiments, the flat surface 124 is oriented to contact the free end 52 (Fig. 15) of the biasing member 48 (Fig. 15) to prevent the biasing member 48 from sliding over the detent 120. In some embodiments, the side wall 104 includes guide slots 126 that slide on the lugs 46 (Fig. 15) of the body 24 (Fig. 15) of the needle hub 12 (Fig. 4).

[0068] Referring now to Figs. 1-3, the assembled pen needle 10 is depicted. In some embodiments, the needle hub 12 is formed by the body 24 coupled to the side wall 26 and the side wall 26 coupled to the base 28. In some embodiments, the base 28 is coupled to the side wall 26 to from the cam tracks 68, 78 (Fig. 5). In some embodiments, the proximal needle shield 18 is positioned in the open proximal end of the needle hub 12 with the cam followers 96 (Figs. 10-12) positioned in a respective recess 66. In some embodiments, the free end 102 (Figs. 10 and 11) of each of the biasing members 98 (Fig. 10) of the proximal needle shield 18 is oriented in the annular space 44 (Fig. 15) of the body 24 to bias the proximal needle shield 18 in a proximal direction. In some embodiments, the distal needle shield 16 is coupled to the needle hub 12 for sliding or moving axially relative to the needle hub 12 from a first extended position shown in Fig. 2 to cover the distal end 20 (Fig. 4) of the needle 14 to a retracted position to expose the needle 14 for the injection.

[0069] In some embodiments, during use, the pen needle 10 is attached to the end of a delivery device where the end of the delivery device is inserted through the opening 92 (Fig. 10) in the proximal needle shield 18. In some embodiments, in the initial position shown in Fig. 2, the proximal needle shield 18 covers the proximal end 22 (Fig. 4) of the needle 14 to reduce the risk of injury to the user. In some embodiments, in the initial position, the cam followers 96 (Fig. 10) of the proximal needle shield 18 are positioned in the recess 74 (Fig. 5) at the proximal end of the first cam track 68 (Fig. 5). In some embodiments, the body 86 (Fig. 10) of the proximal needle shield 18 moves distally by the insertion force of the delivery device to a retracted position where the delivery device can be connected to the pen needle 10 by the internal threads 42 (Fig. 15) of the body 24 of the needle hub 12. In some embodiments, the proximal end 22 (Fig. 4) of the needle 14 is in communication with the delivery device to dispense the medication to the patient. In some embodiments, during the distal movement of the proximal needle shield 18, the cam followers 96 (Fig. 10) slide on the cam surfaces 70, 72 (Fig. 5) of the first cam track 68 (Fig. 5) to the recess 76 (Fig. 5) where the proximal needle shield 18 rotates within the needle hub 12 by the axial movement of the proximal needle shield 18 relative to the needle hub 12. [0070] In some embodiments, the distal end of the distal needle shield 16 is placed against the skin of the patient and an axial force is applied to retract the distal needle shield 16 and the needle 14 penetrates the skin of the patient through an opening in the distal needle shield 16. In some embodiments, the biasing member 48 (Fig. 15) on the body 24 of the needle hub 12 biases the distal needle shield 16 in a distal direction and is compressed by the retracting movement of the distal needle shield 16. In some embodiments, in the initial orientation, the free end 52 (Fig. 15) of the biasing member 48 (Fig. 15) is on a first side of the detent 120 (Fig. 18) on the inner surface of the distal needle shield 16. In some embodiments, the free end 52 (Fig. 15) of the biasing member 48 (Fig. 15) is initially on a side of the inclined surface 122 (Fig. 18). In some embodiments, the retracting movement of the distal needle shield 16 axially compresses the biasing members 48 (Fig. 15) relative to the body 24 of the needle hub 12, where the free ends 52 (Fig. 15) slide around and on the inner surface of the distal needle shield 16. In some embodiments, the distal needle shield 16 is rotationally fixed relative to the needle hub 12 so that the axial movement of the distal needle shield 16 enables the free ends 52 (Fig. 15) of the biasing members 48 (Fig. 15) to slide on the inner surface of the distal needle shield 16 to compress the biasing members 48 (Fig. 15).

[0071] In some embodiments, when the needle 14 is withdrawn from the patient, the biasing members 48 (Fig. 15) return to the original condition and shape and bias the distal needle shield 16 to a second extended position to cover the distal end 20 (Fig. 4) of the needle 14. In some embodiments, as the distal needle shield 16 moves to the extended position and the biasing members 48 (Fig. 15) return to the original configuration, the free ends 52 (Fig. 15) of the biasing members 48 slide over the inclined surface 122 (Fig. 18) of the detent 120 (Fig. 18) to the opposite side of the detent 120. In some embodiments, the free end 52 (Fig. 15) of the biasing member 48 (Fig. 15) then contacts the flat surface 124 (Fig. 18) of the detent 120 (Fig. 18) so that the distal needle shield 16 is retained in the second extended position to cover the distal end 20 (Fig. 4) of the needle 14. In some embodiments, the free ends 52 (Fig. 15) of the biasing members 48 (Fig. 15) contacting the flat surface 124 (Fig. 18) of the detent 120 (Fig. 18) prevents the free ends 52 from sliding over the detent 120 and prevents the distal needle shield 16 from retracting on the needle hub 12.

[0072] In some embodiments, the pen needle 10 is then disconnected from the delivery device so that the biasing members 98 (Fig. 10) of the proximal needle shield 18 bias the body 86 (Fig. 10) of the proximal needle shield 18 in the proximal direction. In some embodiments, the cam followers 96 (Fig. 10) of the proximal needle shield 18 follow the cam surfaces of the second cam track 78 (Fig. 5) to the proximal end where the cam followers 96 align with the proximally facing surface 84 (Fig. 5). In some embodiments, the proximal facing surface 84 (Fig. 5) contacts the cam followers 96 (Fig.

10) to prevent the proximal needle shield 18 from moving distally. In some embodiments, the proximal needle shield 18 is retained in the extended position to cover the proximal end 22 (Fig. 4) of the needle 14.

[0073] 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

CLAIMS What is claimed is:

1. A pen needle comprising: a needle hub having an axial passage, a proximal end configured to couple to a delivery device, and a distal end having a biasing member extending in a distal direction; a needle received in the axial passage of the needle hub and having a distal end extending from the distal end of the needle hub and a proximal end; a proximal needle shield biased relative to the needle hub and movable between an extended position of the proximal needle shield to cover the proximal end of the needle and a retracted position of the proximal needle shield; and a distal needle shield having a distal end and an open proximal end for sliding relative to the needle hub, the distal needle shield being biased distally relative to the needle hub by the biasing member of the needle hub; the distal needle shield having a retaining member for engaging the biasing member of the needle hub to retain the distal needle shield in an extended position of the distal needle shield to cover the distal end of the needle.

2. The pen needle of claim 1, wherein: the biasing member of the needle hub has a first end fixed to the needle hub and a second end contacting an axial inner surface of the distal needle shield; the second end of the biasing member slides on the axial inner surface of the distal needle shield when the distal needle shield moves between the extended position of the distal needle shield and a retracted position of the distal needle shield; and the biasing member of the needle hub compresses axially when the distal needle shield moves to the retracted position of the distal needle shield.

3. The pen needle of claim 2, wherein the retaining member of the distal needle shield comprises a detent extending from the axial inner surface of the distal needle shield to engage the second end of the biasing member to lock the distal needle shield in the extended position of the distal needle shield.

4. The pen needle of claim 2, wherein: the retaining member comprises a detent; the distal needle shield moves from a first extended position of the distal needle shield where the second end of the biasing member is on a first side of the detent so that the distal needle shield can move to the retracted position of the distal needle shield; and the distal needle shield moves from the retracted position of the distal needle shield to a second extended position of the distal needle shield where the second end of the biasing member is on a second side of the detent where the second end of the biasing member contacts the detent to prevent axial movement of the distal needle shield and retain the distal needle shield in the second extended position of the distal needle shield.

5. The pen needle of claim 4, wherein the biasing member of the needle hub has a spiral configuration.

6. The pen needle of any one of claims 1-5, wherein the proximal needle shield has a distal surface comprising a biasing member to bias the proximal needle shield in a proximal direction.

7. The pen needle of claim 6, wherein the biasing member of the proximal needle shield has a first end fixed to the distal surface of the proximal needle shield and a second free end to slide on a proximal surface of the needle hub.

8. The pen needle of claim 7, wherein the proximal needle shield includes a cam follower contacting a cam surface to rotate the proximal needle shield by axial movement of the proximal needle shield relative to the needle hub.

9. The pen needle of claim 8, wherein the proximal needle shield moves from a first extended position of the proximal needle shield to the retracted position of the proximal needle shield and from the retracted position of the proximal needle shield to a second extended position of the proximal needle shield, and where the cam surface prevents axial movement of the proximal needle shield when the proximal needle shield is in the second extended position of the proximal needle shield.

10. The pen needle of claim 9, wherein the biasing member of the proximal needle shield has a spiral configuration.

11. A pen needle comprising: a needle hub having a side wall with an open proximal end, a distal end wall having a biasing member with a first end fixed to the distal end wall and a second end spaced distally from the first end, and a collar spaced radially inward from the side wall and having a proximal end configured for coupling to a delivery device; a needle having a distal end extending from the distal end wall of the needle hub and a proximal end; a proximal needle shield biased relative to the needle hub and moveable between a first extended position of the proximal needle shield to cover the proximal end of the needle, a retracted position of the proximal needle shield, and a second extended position of the proximal needle shield; and a distal needle shield having a distal end and a proximal end for sliding relative to the needle hub, the distal needle shield biased distally relative to the needle hub by the biasing member of the needle hub, the distal needle shield having a retaining member to retain the distal needle shield in an extended position of the distal needle shield to cover the distal end of the needle.

12. The pen needle of claim 11, wherein the retaining member of the distal needle shield comprises a detent on an inner surface of the distal needle shield, and wherein the second end of the biasing member contacts the detent to prevent axial movement of the distal needle shield.

13. The pen needle of claim 11, wherein the biasing member of the needle hub has a spiral configuration.

14. The pen needle of any one of claims 11-13, wherein the proximal needle shield has a distal surface comprising a biasing member to bias the proximal needle shield in a proximal direction.

15. The pen needle of claim 14, wherein the biasing member of the proximal needle shield has a first end fixed to the distal surface of the proximal needle shield and a second free end to slide on a proximal surface of the needle hub.

16. The pen needle of claim 15, where the proximal needle shield includes a cam follower contacting a cam surface to rotate the proximal needle shield by axial movement of the proximal needle shield relative to the needle hub.

17. The pen needle of claim 16, wherein the proximal needle shield moves from the first extended position of the proximal needle shield to the retracted position of the proximal needle shield and from the retracted position of the proximal needle shield to the second extended position of the proximal needle shield, and where the cam surface prevents axial movement of the proximal needle shield when the proximal needle shield is in the second extended position of the proximal needle shield.

18. A pen needle comprising: a needle hub configured to couple to a delivery device and having an axial passage, a proximal end, and a distal end having a biasing member extending in a distal direction; a needle received in the axial passage of the needle hub and having a distal end extending from the distal end of the needle hub and a proximal end; a proximal needle shield movable within the needle hub between an extended position of the proximal needle shield to cover the proximal end of the needle and a retracted position of the proximal needle shield, the proximal needle shield having a biasing member extending from a distal side of the proximal needle shield for contacting a proximal side of the needle hub for biasing the proximal needle shield; and a distal needle shield having a distal end and an open proximal end for sliding relative to the needle hub, the distal needle shield being biased distally relative to the needle hub by the biasing member of the needle hub, the distal needle shield having a locking member for engaging the biasing member of the needle hub to lock the distal needle shield in an extended position of the distal needle shield to cover the distal end of the needle.

19. The pen needle of claim 18, wherein the proximal needle shield includes a cam follower contacting a cam surface on an inner surface of the needle hub to rotate the proximal needle shield by axial movement of the proximal needle shield relative to the needle hub.

20. The pen needle of claim 19, wherein the proximal needle shield moves from a first extended position of the proximal needle shield to the retracted position of the proximal needle shield and from the retracted position of the proximal needle shield to a second extended position of the proximal needle shield, and where the cam surface prevents axial movement of the proximal needle shield when the proximal needle shield is in the second extended position of the proximal needle shield.

21. The pen needle of any one of claims 18-20, wherein the biasing member of the needle hub has a spiral configuration with a first end fixed to the needle hub and a second end contacting an axial inner surface of the distal needle shield, wherein the second end of the biasing member of the needle hub slides on the axial inner surface of the distal needle shield when the distal needle shield moves between the extended position of the distal needle shield and a retracted position of the distal needle shield, and where the biasing member of the needle hub compresses axially when the distal needle shield moves to the retracted position of the distal needle shield.

22. The pen needle of any one of claims 18-20, wherein: the locking member comprises a detent; the distal needle shield moves from a first extended position of the distal needle shield where a second end of the biasing member of the needle hub is on a first side of the detent so that the distal needle shield can move to a retracted position of the distal needle shield; and the distal needle shield moves to a second extended position of the distal needle shield where the second end of the biasing member of the needle hub is on a second side of the detent where the second end of the biasing member of the needle hub contacts the detent to prevent axial movement of the distal needle shield and retain the distal needle shield in the second extended position of the distal needle shield.

23. An injection system, comprising: a delivery device comprising a supply of medication; and a pen needle, comprising: a needle hub having an axial passage, a proximal end configured to couple to the delivery device, and a distal end having a biasing member extending in a distal direction; a needle received in the axial passage of the needle hub and having a distal end extending from the distal end of the needle hub and a proximal end; a proximal needle shield biased relative to the needle hub and movable between an extended position of the proximal needle shield to cover the proximal end of the needle and a retracted position of the proximal needle shield; and a distal needle shield having a distal end and an open proximal end for sliding relative to the needle hub, the distal needle shield being biased distally relative to the needle hub by the biasing member of the needle hub; the distal needle shield having a retaining member for engaging the biasing member of the needle hub to retain the distal needle shield in an extended position of the distal needle shield to cover the distal end of the needle.

24. The injection system of claim 23, wherein: the biasing member of the needle hub has a first end fixed to the needle hub and a second end contacting an axial inner surface of the distal needle shield; the second end of the biasing member slides on the axial inner surface of the distal needle shield when the distal needle shield moves between the extended position of the distal needle shield and a retracted position of the distal needle shield; and the biasing member of the needle hub compresses axially when the distal needle shield moves to the retracted position of the distal needle shield.

25. The injection system of claim 24, wherein the retaining member of the distal needle shield comprises a detent extending from the axial inner surface of the distal needle shield to engage the second end of the biasing member to lock the distal needle shield in the extended position of the distal needle shield.

26. The injection system of claim 24, wherein: the retaining member comprises a detent; the distal needle shield moves from a first extended position of the distal needle shield where the second end of the biasing member is on a first side of the detent so that the distal needle shield can move to the retracted position of the distal needle shield; and the distal needle shield moves from the retracted position of the distal needle shield to a second extended position of the distal needle shield where the second end of the biasing member is on a second side of the detent where the second end of the biasing member contacts the detent to prevent axial movement of the distal needle shield and retain the distal needle shield in the second extended position of the distal needle shield.

27. The injection system of claim 26, wherein the biasing member of the needle hub has a spiral configuration.

28. The injection system of any one of claims 23-27, wherein the proximal needle shield has a distal surface comprising a biasing member to bias the proximal needle shield in a proximal direction.

29. The injection system of claim 28, wherein the biasing member of the proximal needle shield has a first end fixed to the distal surface of the proximal needle shield and a second free end to slide on a proximal surface of the needle hub.

30. The injection system of claim 29, wherein the proximal needle shield includes a cam follower contacting a cam surface to rotate the proximal needle shield by axial movement of the proximal needle shield relative to the needle hub.

31. The injection system of claim 30, wherein the proximal needle shield moves from a first extended position of the proximal needle shield to the retracted position of the proximal needle shield and from the retracted position of the proximal needle shield to a second extended position of the proximal needle shield, and where the cam surface prevents axial movement of the proximal needle shield when the proximal needle shield is in the second extended position of the proximal needle shield.

32. The injection system of claim 31, wherein the biasing member of the proximal needle shield has a spiral configuration.

33. An injection system comprising: a delivery device comprising a supply of medication; and the pen needle of any one of claims 11-22.