Patent Publication Number: US-2022211952-A1

Title: Needle Hub for Drug Delivery Device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. Provisional Application No. 63/134,054, filed Jan. 5, 2021, which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present disclosure relates to a needle hub for a drug delivery device. 
     Description of Related Art 
     Wearable medical devices, such as automatic injectors, have the benefit of providing therapy to the patient at a location remote from a clinical facility and/or while being worn discretely under the patient&#39;s clothing. The wearable medical device can be applied to the patient&#39;s skin and configured to automatically deliver a dose of a pharmaceutical composition within a predetermined time period after applying the wearable medical device to the patient&#39;s skin. After the device delivers the pharmaceutical composition to the patient, the patient may subsequently remove and dispose of the device. 
     SUMMARY OF THE INVENTION 
     In one aspect or embodiment, a needle hub for a drug delivery device includes a hub body, an activation button moveable relative to the hub body, with the activation button having a first actuation surface, and a needle holder moveable relative to the hub body, with the needle holder having a second actuation surface. The first actuation surface of the activation button is configured to engage the second actuation surface of the needle holder. The needle hub further includes a needle attached to the needle holder, a needle spring biasing the needle holder to a retracted position where the needle is positioned within the hub body, a cannula holder moveable relative to the hub body and the needle holder, a cannula attached to the cannula holder, the cannula configured to be in fluid communication with a fluid source, and a cannula spring biasing the cannula holder to a retracted position where the cannula is positioned within the hub body. Movement of the activation button is configured to cause the first actuation surface of the activation button to engage the second actuation surface of the needle holder to move the needle holder and the cannula holder from the respective retracted positions to insertion positions where distal ends of the needle and the cannula are positioned outside of the hub body, with the needle holder configured to return to the retracted position while the cannula holder remains in the insertion position. Further, movement of a portion of the hub body is configured to disengage a connection between the cannula holder and the hub body to allow the cannula holder to return to the retracted position. 
     The needle holder may include a passageway configured to be in fluid communication with a fluid source, with the needle in fluid communication with the passageway of the needle holder. At least a portion of the needle may be received within the cannula, and the cannula holder may include a seal engaged with the needle. The needle hub may include a first projection and the cannula holder may include a second projection, with the first projection of the needle hub engaging the second projection of the cannula holder when the cannula is in the insertion position to restrict movement of the cannula holder to the retracted position. The needle hub may include a removal tab, where movement of the removal tab releases an engagement between the first projection of the needle hub and the second projection of the cannula holder to allow the cannula spring to bias the cannula to the retracted position. At least a portion of the removal tab may be configured to be engaged with a skin surface of a person after attaching the needle hub to a person. 
     The actuator button may be moveable along a first axis, where the needle holder and the cannula holder are moveable along a second axis perpendicular to the first axis. The first actuation surface of the activation button may be configured to disengage from the second actuation surface of the needle holder after movement of the actuation button a predetermined distance along the first axis. 
     The needle hub may include a skin tenting reduction mechanism including an adhesive surface configured to be adhered to a skin surface of a person, with the skin tenting reduction mechanism configured to stretch the skin surface at a location where the needle penetrates the skin surface. 
     In one aspect or embodiment, a needle hub for a drug delivery device includes a hub body, an activation button moveable relative to the hub body, a needle holder moveable relative to the hub body, a needle attached to the needle holder, a cannula holder moveable relative to the hub body and the needle holder, a cannula attached to the cannula holder, with the cannula configured to be in fluid communication with a fluid source, a drive spring configured to bias the needle holder and the cannula holder from a retracted position where the needle and the cannula are positioned within the hub body to an insertion position where distal ends of the needle and the cannula are positioned outside of the hub body, and a retraction spring configured to retract the needle holder from the insertion position to the retracted position. Prior to actuation of the activation button, the drive spring is engaged with the cannula holder, with the needle holder engaged with the cannula holder to prevent movement of the cannula holder. After actuation of the activation button, the needle holder is configured to move relative to the hub body to allow the cannula holder to rotate relative to the needle holder such that the drive spring moves the cannula holder and the needle holder to the insertion position. 
     The hub body may include a first cam surface and the cannula holder may include a second cam surface, where engagement of the second cam surface with the first cam surface is configured to rotate the cannula holder. The needle holder may include a first protrusion and the cannula holder may include a second protrusion, where, prior to actuation of the activation button, the first protrusion of the needle holder engages the second protrusion of the cannula holder to prevent rotation of the cannula holder. The activation button may be configured to be depressed, where depressing the activation button is configured to move the first protrusion of the needle holder from engagement with the second protrusion of the cannula holder to allow the cannula holder to rotate, the first cam surface of the hub body to disengage from the second cam surface of the cannula holder, and the cannula holder and the needle holder to move to the insertion position. After actuation of the activation button and the rotation of the cannula holder, a first drive surface of the cannula holder may be engaged with a second drive surface of the needle holder such that movement of the cannula holder toward the insertion position will also move the needle holder toward the insertion position. After movement of the cannula holder to the insertion position, the needle holder may engage a ramp portion of the hub body to rotate the needle holder such that the first drive surface of the cannula holder is disengaged from the second drive surface of the needle holder to allow the retraction spring to bias the needle holder back to the retracted position. The activation button may be translatable from a first position to a second position, where the activation button is restricted from being depressed when the activation button is in the first position. 
     The needle hub may further include a needle shield covering at least a portion of the needle and the cannula, and a needle shield remover engaged with the hub body, where the needle shield remover prevents movement of the activation button. With the needle holder in the retracted position and the cannula holder in the insertion position, the needle may be positioned entirely outside of the cannula. The cannula holder may include an inlet configured to be in fluid communication with a fluid source, where the cannula holder includes a seal engaged with the needle. The drive spring may be first and second compression springs. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and other features and advantages of this disclosure, and the manner of attaining them, will become more apparent and the disclosure itself will be better understood by reference to the following descriptions of embodiments of the disclosure taken in conjunction with the accompanying drawings. 
         FIG. 1  is schematic view of a drug delivery device according to one aspect or embodiment of the present application. 
         FIG. 2  is a schematic view of the drug delivery device of  FIG. 1 . 
         FIG. 3  is a perspective view of a needle hub according to one aspect or embodiment of the present application. 
         FIG. 4A  is a top view of the needle hub of  FIG. 3 , showing an indicator prior to use of the needle hub. 
         FIG. 4B  is a top view of the needle hub of  FIG. 3 , showing an indicator after insertion of a needle. 
         FIG. 4C  is a top view of the needle hub of  FIG. 3 , showing an indicator after withdrawal of a cannula. 
         FIG. 5  is a schematic view showing a method of using the needle hub of  FIG. 3 . 
         FIG. 6A  is a schematic view of the needle hub of  FIG. 3 , showing actuation of an activation button. 
         FIG. 6B  is a schematic view of the needle hub of  FIG. 3 , showing movement of a needle and a cannula from a retracted position to an insertion position. 
         FIG. 6C  is a schematic view of the needle hub of  FIG. 3 , showing a needle in a retracted position and a cannula in an insertion position. 
         FIG. 6D  is a schematic view of the needle hub of  FIG. 3 , showing movement of a cannula to a retracted position. 
         FIG. 7  is a perspective view of a needle hub according to a further aspect or embodiment of the present application. 
         FIG. 8  is a front view of the needle hub of  FIG. 7 , showing an infusion mode. 
         FIG. 9  is a front view of the needle hub of  FIG. 7 , showing a cannula withdrawal. 
         FIG. 10  is a perspective view of a needle hub according to a further aspect or embodiment of the present application. 
         FIG. 11  is a schematic view showing a method of using the needle hub of  FIG. 7 . 
         FIG. 12A  is a schematic view of the needle hub of  FIG. 7 , showing a pre-use position of the needle hub. 
         FIG. 12B  is a schematic view of the needle hub of  FIG. 7 , showing the needle hub being actuated. 
         FIG. 12C  is a schematic view of the needle hub of  FIG. 7 , showing a needle being retracted. 
         FIG. 12D  is a schematic view of the needle hub of  FIG. 7 , showing a needle in a retracted position. 
         FIG. 12E  is a schematic view of the needle hub of  FIG. 7 , showing an applicator being detached from the needle hub. 
         FIG. 12F  is a schematic view of the needle hub of  FIG. 7 , showing a cannula in a retracted position. 
         FIG. 13  is a cross-sectional view of a needle hub according to a further aspect or embodiment of the present application. 
         FIG. 14  is a cross-sectional view of the needle hub of  FIG. 13 . 
         FIG. 15  is a perspective view of a needle hub according to a further aspect or embodiment of the present application. 
         FIG. 16  is a perspective view of a needle hub according to a further aspect or embodiment of the present application. 
         FIG. 17  is a perspective view of a needle actuation assembly according to one aspect or embodiment of the present application. 
         FIG. 18A  is a cross-sectional view of the needle hub of  FIG. 15 , showing a cannula insertion position. 
         FIG. 18B  is a cross-sectional view of the needle hub of  FIG. 15 , showing a cannula retraction position. 
         FIG. 19  is a perspective view of a needle hub according to a further aspect or embodiment of the present application. 
         FIG. 20  is a schematic view showing a method of using the needle hub of  FIG. 19 . 
         FIG. 21  is a perspective view of a needle actuation assembly according to a further aspect or embodiment of the present application. 
         FIG. 22  is a perspective view of a drug delivery device and needle hub according to a further aspect or embodiment of the present application. 
         FIG. 23  is an exploded perspective view of the drug delivery device and needle hub of  FIG. 22 . 
         FIG. 24  is a perspective view of the drug delivery device and needle hub of  FIG. 22 , showing the drug delivery device and needle hub connected while delivering a medicament. 
         FIG. 25  is a perspective view of the drug delivery device and needle hub of  FIG. 22 , showing the needle hub separated from the drug delivery device while delivering a medicament. 
         FIG. 26A  is a cross-sectional view of a needle hub according to a further aspect or embodiment of the present application, showing an initial position of the needle hub. 
         FIG. 26B  is a cross-sectional view of a needle hub according to a further aspect or embodiment of the present application, showing engagement with a skin surface. 
         FIG. 26C  is a cross-sectional view of a needle hub according to a further aspect or embodiment of the present application, showing insertion of a needle. 
         FIG. 27A  is a cross-sectional view of a needle hub according to a further aspect or embodiment of the present application, showing an initial position of the needle hub. 
         FIG. 27B  is a cross-sectional view of a needle hub according to a further aspect or embodiment of the present application, showing engagement with a skin surface. 
         FIG. 27C  is a cross-sectional view of a needle hub according to a further aspect or embodiment of the present application, showing insertion of a needle. 
         FIG. 28A  is a cross-sectional view of a needle hub according to a further aspect or embodiment of the present application, showing an initial position of the needle hub. 
         FIG. 28B  is a cross-sectional view of a needle hub according to a further aspect or embodiment of the present application, showing engagement with a skin surface. 
         FIG. 28C  is a cross-sectional view of a needle hub according to a further aspect or embodiment of the present application, showing insertion of a needle. 
         FIG. 29  is a perspective view of a needle actuation assembly according to a further aspect or embodiment of the present application, showing an unactuated position. 
         FIG. 30  is a perspective view of the needle actuation assembly of  FIG. 29 , showing an actuated position. 
         FIG. 31  is a cross-sectional view of the needle actuation assembly of  FIG. 29 , showing an unactuated position. 
         FIG. 32  is a cross-sectional view of the needle actuation assembly of  FIG. 29 , showing an actuated position. 
         FIG. 33  is a cross-sectional view of the needle actuation assembly of  FIG. 29 , showing a retracted position. 
         FIG. 34  is a perspective view of a needle hub according to a further aspect or embodiment of the present application. 
         FIG. 35  is a schematic view of the needle hub of  FIG. 34 . 
         FIG. 36  is a perspective view of a drug delivery device according to a further aspect or embodiment of the present application. 
         FIG. 37  is a front view of the drug delivery device of  FIG. 36 . 
         FIG. 38  is a front view of the drug delivery device of  FIG. 36 , showing a reservoir separated from the drug delivery device. 
         FIG. 39  is a front view of the drug delivery device of  FIG. 36 , showing the drug delivery device attached to a patient. 
         FIG. 40  is a partial cross-sectional view of a prior art valve assembly. 
         FIG. 41  is a front cross-sectional view of a needle hub for a drug delivery device according to a further aspect or embodiment of the present application. 
         FIG. 42  is a cutaway perspective view of the needle hub of  FIG. 41 . 
         FIG. 43  is a cutaway perspective view of the needle hub of  FIG. 41 , showing a needle shield remover. 
         FIG. 44  is a side cross-sectional view of the needle hub of  FIG. 41 , showing a pre-use position of the needle hub. 
         FIG. 45  is a side cross-sectional view of the needle hub of  FIG. 41 , showing a needle shield remover removed from the needle hub. 
         FIG. 46  is a side cross-sectional view of the needle hub of  FIG. 41 , showing initial movement of an activation button. 
         FIG. 47  is a partial perspective view of the needle hub of  FIG. 41 , showing an activation button according to one aspect or embodiment of the present application. 
         FIG. 48  is a partial perspective view of the needle hub of  FIG. 41 , showing a retracted position of a needle holder and cannula holder. 
         FIG. 49  is a side cross-sectional view of the needle hub of  FIG. 41 , showing an activation button being depressed. 
         FIG. 50  is a partial perspective view of the needle hub of  FIG. 41 , showing an activation button being depressed. 
         FIG. 51  is a side cross-sectional view of the needle hub of  FIG. 41 , showing a needle holder and a cannula holder in an insertion position. 
         FIG. 52  is a partial perspective view of the needle hub of  FIG. 41 , showing initial rotation of a needle holder. 
         FIG. 53  is a partial perspective view of the needle hub of  FIG. 41 , showing final rotation of a needle holder. 
         FIG. 54  is a side cross-sectional view of the needle hub of  FIG. 41 , showing a needle holder in a retracted position and a cannula holder in an insertion position. 
         FIG. 55  is an enlarged perspective view of the area shown in  FIG. 54 . 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate exemplary embodiments of the disclosure, and such exemplifications are not to be construed as limiting the scope of the disclosure in any manner. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Spatial or directional terms, such as “left”, “right”, “inner”, “outer”, “above”, “below”, and the like, are not to be considered as limiting as the invention can assume various alternative orientations. 
     All numbers used in the specification and claims are to be understood as being modified in all instances by the term “about”. By “about” is meant a range of plus or minus ten percent of the stated value. As used in the specification and the claims, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. The terms “first”, “second”, and the like are not intended to refer to any particular order or chronology, but instead refer to different conditions, properties, or elements. By “at least” is meant “greater than or equal to”. 
     Referring to  FIGS. 1-3 , a drug delivery device  10  includes a reservoir  12 , a power module  14 , an insertion mechanism  16 , control electronics  18 , and a housing  20 . In one aspect or embodiment, the drug delivery device  10  is a wearable automatic injector. The drug delivery device  10  may be mounted onto the skin of a patient and triggered to inject a pharmaceutical composition from the reservoir  12  into the patient. The drug delivery device  10  may be pre-filled with the pharmaceutical composition, or it may be filled with the pharmaceutical composition by the patient or medical professional prior to use. The control electronics  18  may include a processor  22 , such as a microcontroller, a motor driver  23 , a sensing module  24 , a visual driver  25 , and/or audio driver  26 . The drug delivery device  10  includes a drive mechanism  27  configured to dispense fluid from the reservoir  12 . The drive mechanism  27  may be motor powered, spring powered, hydraulic powered, pneumatic powered, and/or other suitable drive mechanism. 
     The drug delivery device  10  is configured to deliver a dose of a pharmaceutical composition, e.g., any desired medicament, into the patient&#39;s body by a subcutaneous injection at a slow, controlled injection rate. Exemplary time durations for the delivery achieved by the drug delivery device  10  may range from about 5 minutes to about 60 minutes, but are not limited to this exemplary range. Exemplary volumes of the pharmaceutical composition delivered by the drug delivery device  10  may range from about 10 milliliters to about 50 milliliters, but are not limited to this exemplary range. The volume of the pharmaceutical composition delivered to the patient may be adjusted. The drug delivery device  10  may communicate with another device, such as a mobile device or computer. 
     Referring to  FIGS. 3-6D , according to one aspect or embodiment, the insertion mechanism  16  includes a needle hub  30  separate from the housing  20 . The needle hub  30  includes a removal tab  32 , an activation button  34 , a status indicator  36 , a finger grip, side grips, and an integrated cannula withdrawal tab  38 . The needle hub  30  includes an in-dwelling cannula. The status indicator  36  may be white when unused ( FIG. 4A ), blue when the needle has been inserted and ready to infuse ( FIG. 4B ), and green when the cannula has been withdrawn ( FIG. 4C ). As shown in  FIG. 5 , the needle hub  30  is used by removing the packaging, removing an adhesive liner from the bottom of the needle hub  30 , attaching the needle hub  30  to a skin surface, and squeezing the activation button  34 , which causes the needle to automatically retract leaving an in-dwelling cannula in the patient. The medicament or fluid is then infused into the patient. Once the infusion is complete, the cannula withdrawal tab  38  is pulled, which retracts the cannula. The needle hub  30  can then be removed from the skin of the patient. 
     Referring to  FIGS. 6A-6D , in one aspect or embodiment, the needle hub  30  includes a hub body  42 , the activation button  34 , a needle holder  44 , a needle  46  attached to the needle holder  44 , a needle spring  48 , a cannula holder  50 , a cannula  52  attached to the cannula holder  50 , and a cannula spring  54 . The activation button  34  is moveable relative to the hub body  42  and has a first actuation surface  56 . The needle holder  44  is moveable relative to the hub body  42  and has a second actuation surface  58 . The first actuation surface  56  of the activation button  34  is configured to engage the second actuation surface  58  of the needle holder  44 . The needle spring  48  biases the needle holder  44  to a retracted position where the needle  46  is positioned within the hub body  42 . The cannula holder  50  is moveable relative to the hub body  42  and the needle holder  44 . The cannula  52  is configured to be in fluid communication with a fluid source, such as the fluid reservoir  12 . The cannula spring  54  biases the cannula holder  50  to a retracted position where the cannula  52  is positioned within the hub body  42 . Movement of the activation button  34  is configured to cause the first actuation surface  56  of the activation button  34  to engage the second actuation surface  58  of the needle holder  44  to move the needle holder  44  and the cannula holder  50  from the respective retracted positions to insertion positions where distal ends of the needle  46  and the cannula  52  are positioned outside of the hub body  42 , with the needle holder  44  configured to return to the retracted position while the cannula holder  50  remains in the insertion position. Movement of a portion of the hub body  42  is configured to disengage a connection between the cannula holder  50  and the hub body  42  to allow the cannula holder  50  to return to the retracted position. 
     Referring again to  FIGS. 6A-6D , the needle holder  44  includes a passageway  60  configured to be in fluid communication with the fluid reservoir  12 , with the needle  46  in fluid communication with the passageway  60  of the needle holder  44 . At least a portion of the needle  46  is received within the cannula  52 . Fluid is configured to flow from the fluid reservoir  12  via tubing  62  to the passageway  60  of the needle holder  44 , through the needle  46 , and into the cannula  52 . The cannula holder  50  includes a seal  64  engaged with the needle  46 . The needle hub  30  includes a first projection  66  and the cannula holder  50  includes a second projection  68 , with the first projection  66  of the needle hub  66  engaging the second projection  68  of the cannula holder  50  when the cannula  52  is in the insertion position to restrict movement of the cannula holder  50  to the retracted position. 
     Referring to  FIGS. 3-6D , the needle hub  30  includes a removal tab  70 , where movement of the removal tab  70  releases an engagement between the first projection  66  of the needle hub  30  and the second projection  68  of the cannula holder  50  to allow the cannula spring  54  to bias the cannula  52  to the retracted position. At least a portion of the removal tab  70  is configured to be engaged with a skin surface of a person after attaching the needle hub  30  to a person. The actuator button  34  is moveable along a first axis  72 , and the needle holder  44  and the cannula holder  50  are moveable along a second axis  74  perpendicular to the first axis  72 . The first actuation surface  56  of the activation button  34  is configured to disengage from the second actuation surface  58  of the needle holder  44  after movement of the actuation button  34  is a predetermined distance along the first axis  72 . 
     Referring to  FIGS. 7-14 , a needle hub  80 , according to a further aspect or embodiment, includes an applicator  82  having a needle holder  84 , a needle  86  attached to the needle holder  84 , a needle retraction spring  88 , and an activation button  90 , and a hub body  92  having a cannula holder  94 , a cannula  96  attached to the cannula holder  94 , a cannula withdrawal button  98 , and a cannula retraction spring  100 . At least a portion of the hub body  92  is configured to be received within the applicator  82  and the applicator  82  is configured to be separated from the hub body  92 . Movement of the activation button  90  is configured to move the needle holder  84  and the cannula holder  94  from a retracted position, where the needle  86  and the cannula  96  are positioned within the applicator  82  or hub body  92 , to an insertion position, where distal ends of the needle  86  and the cannula  96  are positioned outside of the applicator  82  and hub body  92 . The cannula withdrawal button  98  locks the cannula holder  94  in the insertion position against a biasing force of the cannula retraction spring  100  when the cannula holder  94  is moved from the retracted position to the insertion position. As shown in  FIG. 10 , in one aspect or embodiment, the cannula withdrawal button  98  may be omitted. 
     Referring to  FIGS. 12A-12F , the needle holder  84  is configured to move to the retracted position after movement of the cannula holder  94  to the insertion position. The activation button  90  includes an extension  102  having a drive protrusion  103  and the applicator  82  includes a drive surface  104  configured to engage the drive protrusion  103 . Upon movement of the activation button  90 , the drive protrusion  103  engages the needle holder  84  to move the needle holder  84  and the cannula holder  94  to the insertion position, with the drive protrusion  103  engaging the drive surface  104  of the applicator  82  to move the extension  102  radially outward thereby releasing the needle holder  84  from the drive protrusion  103  to allow the needle retraction spring  100  to return the needle holder  84  to the retracted position. Actuation of the cannula withdrawal button  98  is configured to move the cannula holder  94  from the insertion position to the retracted position. The hub body  92  further includes an adhesive pad  105  configured to secure the hub body  92  to a skin surface of a person. The adhesive pad  105  includes a removal tab  106  extending radially outward from the hub body  92 . The activation button  90  is received within an opening  107  defined by a body  108  of the applicator  82 . The cannula holder  94  includes a port  109  configured to be in fluid communication with the fluid reservoir  12 , with the cannula  96  in fluid communication with the port  109 . Tubing  110  is connected to the port of the cannula holder  94 . 
     Referring to  FIG. 11 , in one aspect or embodiment, the needle hub  80  is used by removing the packaging, removing an adhesive liner, attaching the needle hub  80  to a skin surface of a patient and removing a safety cap, and pressing the activation button  90  of the applicator  82 , which automatically actuates and retracts the needle  86  to leave the in-dwelling cannula  96 . The applicator  82  can then be removed from the hub body  92  and the infusion can commence. Once the infusion is complete, the cannula withdrawal button  98  may be pressed to remove the cannula  96  from the patient, with the hub body  92  being removed from the skin of the patient using the removal tab  106 . 
     Referring to  FIGS. 13 and 14 , in one aspect or embodiment, the cannula holder  94  includes a portion of the adhesive pad  105 , which removes a portion of the adhesive pad  105  from the skin of the patient when the cannula holder  94  is removed from the hub body  92  to facilitate easier removal of the remainder of the adhesive pad  105  from the skin of the patient. 
     Referring to  FIGS. 15-18B , a needle hub  112  according to a further aspect or embodiment, includes a hub body  114 , an activation button  116 , a needle holder  118  and a needle  120  attached to the needle holder  118 , a cannula holder  122  and a cannula  124  attached to the cannula holder  122 , a needle actuation mechanism  126 , and a cannula spring  128 . The needle actuation mechanism  126  is configured to move the needle holder  118  and the cannula holder  122  from a retracted position to an insertion position and is configured to move the needle holder  118  back to the retracted position. The needle actuation mechanism  126  includes a cam track  130 , a cam member  132  received within the cam track  130 , and a torsion spring  134 . The torsion spring  134  biases the cam member  132  relative to the cam track  130 . The cannula spring  128  biases the cannula holder  122  to a retracted position. Movement of the activation button  116  is configured to cause the needle holder  118  and the cannula holder  122  to move from the retracted position to the insertion position, with the needle holder  118  configured to return to the retracted position while the cannula holder  122  remains in the insertion position. As shown in  FIG. 16 , in one aspect or embodiment, the needle hub  112  includes two lateral activation squeeze buttons  116 . The needle hub  112  is used in the same manner as described above in connection with the needle hub  30  shown in  FIG. 5 . 
     Referring to  FIGS. 17-18B , the hub body  114  includes a cannula lock  136  configured to lock the cannula holder  122  in the insertion portion. The needle hub  112  includes an adhesive pad  138  configured to secure the hub body  114  to a skin surface of a person, with the adhesive pad  138  including a removal tab  140 . Movement of the removal tab  140  is configured to disengage the cannula lock  136  and the hub body  114  to allow the cannula holder  122  to return to the retracted position. The cannula lock  136  is biased away from the cannula holder  122  via a lock spring  142 , where the hub body  112  includes a hinged portion  144 , with the hinged portion  144  configured to rotate upon movement of the removal tab  140  and disengage from the cannula lock  136 . The cannula holder  122  includes a port  146  configured to be in fluid communication with the fluid reservoir  12 , with the cannula  124  in fluid communication with the port  146 . The needle hub  112  includes tubing  148  connected to the port  146  of the cannula holder  122 . The cannula holder  122  includes a seal  150  engaged with the needle  120 , with at least a portion of the needle  120  received within the cannula  124 . 
     Referring to  FIGS. 19-21 , a needle hub  152 , according to a further aspect or embodiment, includes a needle holder  154  and a needle  156  attached to the needle holder  154 , a needle actuation assembly  158  configured to move the needle holder  154  from a retracted position, to an insertion position, and back to the retracted position, and a pressure interlock  160  including an inlet  162  configured to be in fluid communication with the fluid reservoir  12 , an outlet  164  in fluid communication with the needle  156 , and a lock member  166 . The lock member  166  has a first position where the lock member  166  prevents actuation of the needle actuation assembly  158  and a second position where the lock member  166  allows actuation of the needle actuation assembly  158 . The lock member  166  is moved from the first position to the second position based on a pressure within the pressure interlock  160 . 
     Referring to  FIG. 21 , the lock member  166  isolates the inlet  162  from the outlet  164  when the lock member  166  is in the first position, and the lock member  166  allows fluid communication between the inlet  162  and the outlet  164  when the lock member  166  is in the second position. The needle hub  152  further includes tubing  168  connected to the outlet  164  and in fluid communication with the needle  156 . The lock member  166  comprises an opening  170 , with a portion of the needle actuation assembly  158  extending through the opening  170  of the lock member  166  when the lock member  166  is in the second position. The needle actuation assembly  158  includes a cam track  172 , a cam member  174 , and an actuation spring  176  biasing the cam member  174  relative to the cam track  172 . A cam block  178  defines the cam track  172 , with the cam block  178  extending through the opening  170  of the lock member  166  when the lock member  166  is in the second position. The needle actuation assembly  158  further includes a cannula  180 , where the needle  156  is received within the cannula  180  when the needle holder  154  is in the retracted position. 
     Referring again to  FIGS. 19-21 , the needle hub  152  includes a housing  182  and a removal tab  184 . A top surface  186  of the housing  182  is smooth and free of activation buttons. As shown in  FIG. 20 , the needle hub  152  is used by removing packaging, removing an adhesive liner, attaching the needle hub  152  to a skin surface of a patient, and activating the drive mechanism  27  to insert the needle  156 , with the needle  156  automatically retracting leaving the in-dwelling cannula  180 . After infusion is complete, the needle hub  152  is removed by grasping the removal tab  184  and lifting upwards, with the cannula  180  automatically retracting. In one aspect or embodiment, pulling the removal tab  184  causes a drop in pressure of the pressure interlock  160  to cause the cannula holder and/or the cannula  180  to automatically retract. 
     Referring to  FIGS. 22-25 , a drug delivery device  190  and a needle hub  192 , according to a further aspect or embodiment, is shown. The drug delivery device  190  may be similar to the drug delivery device  10  shown in  FIGS. 1 and 2 . The drug delivery device  190  and the needle hub  192  of  FIGS. 22-25 , however, is modular, with the needle hub  192  optionally integrated within the drug delivery device  190  ( FIG. 24 ) or with the needle hub  192  separated from the drug delivery device  190  and separately attached to a skin surface of a patient ( FIG. 25 ). In one aspect or embodiment, the drug delivery device  190  and the needle hub  192  may remain connected or integral for lower drug volume and separated with a fluid connection therebetween for larger drug volumes. 
     Referring to  FIGS. 26A-26C , a needle hub  200  with a skin tenting reduction feature, according to one aspect or embodiment, is shown. The needle hub  200  includes a rotating engagement mechanism  202 , with a portion of the rotating engagement mechanism  202  first contacting a skin surface of the patient and adhering to the skin surface and further rotating as the needle hub  200  is fully pressed onto the skin surface. The initial adherence and further rotation of the rotating engagement mechanism stretches the skin to reduce skin tenting. 
     Referring to  FIGS. 27A-27C , a needle hub  204  with a skin tenting reduction feature, according to one aspect or embodiment, is shown. The needle hub  204  includes an adhesive ring  206  that is pressed onto the skin prior to insertion of a needle when an activation button is depressed or actuated. The adhesive ring  206  stretches the skin to reduce skin tenting. 
     Referring to  FIGS. 28A-28C , a needle hub  208  with a skin tenting reduction feature, according to one aspect or embodiment, is shown. The needle hub  208  includes a skin stretching member  210  that is moved radially outward after being initially adhered to a skin surface of a patient. An activation button  212  engages the skin stretching member  210  to move the skin stretching member  210  radially outward, which stretches the skin locally to reduce skin tenting. 
     The skin tenting reduction features and associated mechanisms of  FIGS. 26A-28C  may be incorporated into any of the aspect or embodiments of the needle hub or needle insertion arrangements disclosed herein. 
     Referring to  FIGS. 29-33 , a needle actuation assembly  220 , according to one aspect or embodiment, includes a clip  222  that holds a needle actuator body  224  and cannula body  226  in the retracted position, which are biased by a spring  228 . Pushing the clip  222  inwards releases the needle actuator body  224  and cannula body  226  to cause insertion of a needle  230  and a cannula  232 . When the cannula body  226  reaches the bottom of a housing  233 , the cannula body  226  contacts angled features causing the cannula body  226  to rotate and/or twist. The cannula body  226  is held down by clips  236  in the walls of the housing  233 . After the cannula body  226  rotates and/or twists, the needle actuator body  224  is released and a return spring  238  retracts the needle  230 . 
     Referring to  FIGS. 34 and 35 , a needle hub  240 , according to a further aspect or embodiment, is configured to be decoupled from remaining components of a drug delivery device. The needle hub  240  includes a protective cap  242 , a needle insertion mechanism  244 , a connection arrangement  246  configured to place the needle hub  240  in fluid communication with the reservoir  12  and the drive mechanism  27 , a fluid path  248 , and an adhesive pad and/or layer  250 . The connection arrangement  246  may provide for aseptic connection between the needle hub  240  and the reservoir  12 . The needle retraction may be manually activated or automatically activated via a triggering mechanism connected to an end of dose event and/or a wireless connection between the driving unit and the needle hub  240 . The triggering mechanism may include a flexible rigid connection to plunger rod movement (totally or partially at the end of translation). The fluid path  248  and connection arrangement  246  is maintained sterile until the connection is established, with sterilization of the sub-system and the reservoir  12 . 
     Referring to  FIGS. 36-39 , a drug delivery device  252 , according to a further aspect or embodiment, includes a flexible reservoir  254 , with at least a portion of the flexible reservoir  254  positioned externally from a remaining portion of the drug delivery device  252 . The drug delivery device  252  may be similar to the drug delivery device  10  shown in  FIGS. 1 and 2 . As shown in  FIG. 39 , for smaller volumes, such as 10 mL-30 mL, the flexible reservoir  254  may be directly attached to the drug delivery device  252  and worn on a skin surface of the patient. As shown in  FIG. 38 , for larger volumes, such as 50 mL, the flexible reservoir  254  may be separated from the drug delivery device  252  and fluidly connected to the drug delivery device  252  via a fluid path  256 , such as a tube. The flexible reservoir  254  may be separately attached to the patient via a belt clip, harness, strap, or other suitable arrangement. 
     Referring to  FIG. 40 , the drug delivery devices in any of the aspects or embodiments discussed above may utilize a valve assembly  260  that engages a reservoir and/or container to facilitate the fluid connection between the reservoir and/or container and the fluid path to the needle and/or cannula. The valve assembly  260  may be similar to and operate in the same manner as the valve assembly shown and described in U.S. Patent Application Publication No. 2017/0354788. 
     Referring to  FIGS. 41-54 , in a further aspect or embodiment, a needle hub  270  for a drug delivery device includes a hub body  272 , an activation button  274  moveable relative to the hub body  272 , a needle holder  276  moveable relative to the hub body  272 , a needle  278  attached to the needle holder  276 , a cannula holder  280  moveable relative to the hub body  272  and the needle holder  276 , a cannula  282  attached to the cannula holder  280 , with the cannula  282  configured to be in fluid communication with a fluid source, such as the reservoir  12 , a drive spring  284  configured to bias the needle holder  276  and the cannula holder  280  from a retracted position where the needle  278  and the cannula  282  are positioned within the hub body  272  to an insertion position where distal ends of the needle  278  and the cannula  282  are positioned outside of the hub body  272 , and a retraction spring  286  configured to retract the needle holder  276  from the insertion position to the retracted position. Prior to actuation of the activation button  274 , the drive spring  284  is engaged with the cannula holder  280 , with the needle holder  276  engaged with the cannula holder  280  to prevent movement of the cannula holder  280 . After actuation of the activation button  274 , the needle holder  276  is configured to move relative to the hub body  272  to allow the cannula holder  280  to rotate relative to the needle holder  276  such that the drive spring  284  moves the cannula holder  280  and the needle holder  276  to the insertion position. The hub body  272  includes a first cam surface  288  and the cannula holder  280  includes a second cam surface  290 , and where engagement of the second cam surface  290  with the first cam surface  288  is configured to rotate the cannula holder  280 . The cannula holder  280  includes an inlet  292  configured to be in fluid communication with a fluid source, such as the fluid reservoir  12 , and the cannula holder  280  includes a seal  294  engaged with the needle  278 . The drive spring  284  includes first and second compression springs, although one or more drive springs  284  may be utilized. 
     Referring to  FIG. 48 , the needle holder  276  includes a first protrusion  296  and the cannula holder  280  includes a second protrusion  298 , where, prior to actuation of the activation button  274 , the first protrusion  296  of the needle holder  276  engages the second protrusion  298  of the cannula holder  280  to prevent rotation of the cannula holder  280   
     Referring to  FIGS. 49 and 50 , the activation button  274  is configured to be depressed. Depressing the activation button  274  is configured to move the first protrusion  296  of the needle holder  276  from engagement with the second protrusion  298  of the cannula holder  280  to allow the cannula holder  280  to rotate, the first cam surface  288  of the hub body  272  to disengage from the second cam surface  290  of the cannula holder  280 , and the cannula holder  280  and the needle holder  276  to move to the insertion position. After actuation of the activation button  274  and the rotation of the cannula holder  280 , a first drive surface  302  of the cannula holder  280  is engaged with a second drive surface  304  of the needle holder  276  such that movement of the cannula holder  280  toward the insertion position will also move the needle holder  276  toward the insertion position. 
     Referring to  FIGS. 51-53 , after movement of the cannula holder  280  to the insertion position, the needle holder  276  engages a ramp portion  306  of the hub body  272  to rotate the needle holder  276  such that the first drive surface  302  of the cannula holder  280  is disengaged from the second drive surface  304  of the needle holder  276  to allow the retraction spring  286  to bias the needle holder  276  back to the retracted position. 
     Referring to  FIGS. 41-49 , the activation button  274  is translatable from a first position to a second position, with the activation button  274  restricted from being depressed when the activation button  274  is in the first position. As shown in  FIG. 47 , the activation button  274  or another portion of a drug delivery device may include a biasing member  308  to provide resistance to the activation button  274  as the activation button  274  is translated from the first position to the second position. 
     Referring to  FIGS. 41-44 , the needle hub  270  includes a needle shield  310  covering at least a portion of the needle  278  and the cannula  282 , and a needle shield remover  312  engaged with the hub body  272 . The needle shield remover  312  prevents movement of the activation button  274  when the needle shield remover  312  is engaged with the hub body  272 . 
     Referring to  FIG. 54 , with the needle holder  276  in the retracted position and the cannula holder  280  in the insertion position, the needle  278  is positioned entirely outside of the cannula  282 . With the needle  278  positioned entirely outside of the cannula  282 , the fluid flow through the cannula  282  is maximized. 
     Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present invention contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.