Abstract:
A pharmaceutical delivery device with triggered automatic needle insertion and manually controlled pharmaceutical injection. The pharmaceutical delivery device includes a housing, a pharmaceutical containing needled syringe having an injection tip that is recessed within the housing when the syringe is in a first position and which projects from the housing when the syringe is in a second position, a syringe advancing assembly operable to automatically advance the needled syringe from the first position to the second position, a plunger including an input portion projecting from the housing for manual access by a user, wherein the plunger is operable by the user directly shifting the input portion when the syringe is disposed in the second position to inject pharmaceutical from the syringe through the needle at a rate adjustably controlled by a user during the injection, and wherein the plunger includes a plunger extender automatically movable within the housing from a first location to a second location upon the needled syringe advancing from the first position to the second position, wherein the plunger extender, when in the second location, occupies a space vacated by the needled syringe during advancement from the first position to the second position, whereby the plunger input portion remains stationary relative to the housing during the advancement of the needled syringe.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention pertains to pharmaceutical delivery devices, and, in particular, to a pharmaceutical delivery device having an automatic needle insert. 
         [0002]    Patients suffering from a number of different diseases frequently must inject themselves with pharmaceuticals. As some patients find it difficult to insert a needle of an injector into one&#39;s skin, a variety of devices have been developed to facilitate this insertion task. 
         [0003]    One type of such device automatically inserts a needle and then automatically injects a dose of medication through the inserted needle. With one version of this type device, after unlocking the device by manually twisting a handle, a patient needs to position the device against an injection site, and then operate a trigger of the device, such as by pressing the device firmly against the site. Trigger operation first causes a needled syringe within a housing of the device to shift such that its needle penetrates the skin, and then without further trigger operation or other user input, automatically causes a piston within the syringe to move to force the syringe contents through the inserted needle and into the patient. While this type of device may be useful for some patients, other patients may object to lacking control of the rate at which the injection process occurs. 
         [0004]    Another known device disclosed in U.S. Pat. No. 5,980,491 mounts an injection pen therein and allows the needle of that pen to be automatically inserted into an injection site, whereafter the injection pen can be manually controlled to inject medication at a desired rate. However, because during needle insertion the injection pen is driven axially relative to the device, the patient may be startled or uncomfortable with the visible shifting of the pen, and further may have to readjust his or her hand to properly position a digit over the pen plunger before manually controlling the injection. 
         [0005]    Thus, it would be desirable to provide a device that can overcome one or more of these and other shortcomings of the prior art. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    In one form thereof, the present invention provides a pharmaceutical delivery device including a housing having a first end and a second end spaced in an axial direction, a pharmaceutical containing needled syringe mounted within the housing to be movable in the axial direction from a first position to a second position, wherein an injection tip of the syringe needle is recessed within the housing when in the first position and projects from the housing beyond the first end when in the second position, a syringe advancing assembly operable to automatically advance the needled syringe from the first position to the second position, and a plunger including an input portion projecting from the housing for manual access by a user, wherein the plunger is operable by the user directly shifting the input portion when the needled syringe is disposed in the second position to inject pharmaceutical from the syringe through the needle at a rate adjustably controlled by a user during the injection. The plunger also includes a plunger extender automatically movable within the housing from a first location to a second location upon the needled syringe advancing from the first position to the second position. The plunger extender, when in the second location, occupies a space vacated by the needled syringe during advancement from the first position to the second position, whereby the plunger input portion remains stationary relative to the housing during the advancement of the needled syringe. 
         [0007]    One advantage of the present invention is that a pharmaceutical delivery device having automatic needle insertion, manual dose injection operability may be provided that is easy and intuitive to operate. 
         [0008]    Another advantage of the present invention is that a pharmaceutical delivery device with automatic needle insertion may be provided in which its user controlled injecting plunger remains stationary relative to the device housing during needle insertion. 
         [0009]    Yet another advantage of the present invention is that a pharmaceutical delivery device may be provided in which an automatic insertion of the device needle is performed by pressing toward an injection site a button disposed on another portion of the device most distant from the injection site. 
         [0010]    Yet another advantage of the present invention is that a pharmaceutical delivery device may be provided in which a trigger button for an automatic needle insertion is disposed on the plunger for manually controlling injection, whereby both the button and plunger can be operated without a user needing to change her hand position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0011]    The above-mentioned and other advantages and objects of this invention, and the manner of attaining them, will become more apparent, and the invention itself will be better understood, by reference to the following description of embodiments of the invention taking in conjunction with the accompanying drawings, wherein: 
           [0012]      FIG. 1  is a front perspective view of a pharmaceutical delivery device of the present invention, which device is shown arranged in a ready to insert configuration; 
           [0013]      FIG. 2  is a longitudinal cross-sectional view of the delivery device of  FIG. 1 ; 
           [0014]      FIG. 3  is a diagrammatic, partial side view of the plunger shaft, trigger, and lock sleeve of the delivery device of  FIG. 1 , wherein such components are shown free of all the other device components; 
           [0015]      FIG. 3A  is a cross-sectional view taken along line  3 A- 3 A of  FIG. 3 ; 
           [0016]      FIG. 4  is a view of the delivery device of  FIG. 2  after its automatic needle insertion function has been completed, whereby the device is shown arranged in a ready to inject configuration; and 
           [0017]      FIG. 5  is a cross-sectional front view of the delivery device of  FIG. 1  prior to a replacement syringe mounting being completed. 
       
    
    
       [0018]    Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent an embodiment of the present invention, the drawings are not necessarily to scale, and certain features may be exaggerated or omitted in some of the drawings in order to better illustrate and explain the present invention. 
       DETAILED DESCRIPTION OF THE INVENTION  
       [0019]    Referring now to  FIG. 1 , there is shown a first embodiment of a pharmaceutical delivery device of the present invention. Any directional references in this detailed description with respect to  FIG. 1  or any of the other Figures, such as up or down, or top or bottom, are intended for convenience of description, and by itself does not limit the present invention or any of its components to any particular positional or spatial orientation. 
         [0020]    The delivery device, generally designated  20 , includes an outer housing, generally designated  22 , having a distal end  24  and a proximal end  26 . As used herein, distal and proximal refer to axial locations on the delivery device relative to an injection site when the device is oriented for use at such site, whereby, for example, proximal end of the housing refers to the housing end that is closest to such injection site. 
         [0021]    Outer housing  22  includes a cylindrical tubular body  30 , a cap member  32 , and a needle shield  34 . Body  30  is made of plastic and has an interior hollow  38  that extends longitudinally or axially, in which axial direction the syringe is driven during needle insertion. Body  30  has a radial periphery covered with a resilient gripping layer  31  made of a softer material and with a convex contour which facilitates the housing being grasped more comfortably and reliably within the hand of a user. Cap member  32 , which is securely attached to body  30  during manufacture in a suitable fashion, forms the housing distal end  24 . Cap member  32  is made of plastic and includes a central opening  35  through which a plunger shaft is movable axially. Housing  22  and a plunger, generally designated  40 , are keyed together in a suitable fashion to be rotatably fixed together, such as via a keying of shaft  46  with body  30 . Plunger  40  and cap member  32  further are complementarily configured, such as via a not shown step-downed neck of the plunger shaft around which a two-piece cap member  32  is installed during manufacture, to prevent plunger  40  from being completely withdrawn from within the housing after manufacture. Needle shield  34  is made of plastic with a tapering contour and a flared proximal end. Needle shield  34  may be transparent to allow the injection site and the needle tip to be observed by a user, and further may have a colored circle or a cross-hair design around the opening  35  to help a user observe an injection site. Opening  35  allows needle  115  to pass therethrough and pierce the injection site against which the proximal face of the needle shield has been placed for administration of the medication. 
         [0022]    Plunger  40  is molded from plastic and includes an enlarged, disc or cylindrical shaped head  42 , and a tubular, cylindrical shaft  46  that depends from the proximal face  43  of head  42 . Head  42  and the distal portion of shaft  46  project distally beyond the distal end of housing  22 , and head  42  is manually pressable by a user to plunge the plunger  40  to cause an injection as described further below. Shaft  46  includes an interior bore  48  within its distal region that open into a cylindrical hollow  45  formed into the distal face  44  of head  42 . Shaft  46  includes a reduced diameter portion  50  at its proximal end, and the proximal region  49  of the larger diameter shaft portion includes an annular bore or hollow  52 . The proximal end of shaft region  49  has an inturned lip  54  that forms a supportive shoulder for the proximal end of a biasing member  56 , such as a metal coiled spring, that serves as a reset spring for the reloadable device shown. Plunger portions  42 ,  46  and  50  may be formed together in one piece. 
         [0023]    The distal end of spring  56  abuts an outturned lip  62  of an extender portion of the plunger, generally designated  60 . Plunger extender  60  is molded of plastic and includes a tubular barrel  64  with a closed proximal end face  66  that fits within a syringe to directly contact a syringe piston for advancement. Barrel  64  is rotatably fixed with and telescopically fits over reduced diameter shaft portion  50 , and is sized to axially slide therealong and within the annular space between shaft portion  50  and shaft lip  54 . Plunger extender  60  includes a not shown latching module that engages a corresponding, not shown latching module of shaft  46 , such as a module on shaft portion  50 , when plunger extender  60  has finished being shifted proximally relative to shaft  46  during needle insertion as described further below. Any suitable latching module known in the art may be employed, such as one or more resilient finger(s) with a latching nub(s) of one of the shaft or plunger extender fitting into or over a nub-receiving opening(s) or recess(es) or end face of the other of the shaft or plunger extender. 
         [0024]    An axially plungable trigger for needle insertion, which trigger is generally designated  70 , is molded in one piece from plastic and includes enlarged head  72  and shaft  74 . Head  72  is disc or button-shaped and disposed at the distal end of device  20  for convenient manual access by a user. Head  72  is sized-to fit within hollow  45 . Shaft  74  depends from the proximal face of trigger button  72  and slidably fits within plunger shaft bore  48 . Trigger  70  is rotatably fixed within plunger  40 , such as via a keying of plunger shaft  46  with trigger shaft  74 . At the proximal end of shaft  74 , a pair of diametrically opposed tabs  76  radially outwardly project and fit within a pair of diametrically opposed openings  78  formed in plunger shaft  46 . Not shown relief notches allow the tabs  76  to flex inwardly during assembly of the trigger to the plunger shaft. Openings  78  and tabs  76  define the possible range of axial motion of trigger  70  relative to plunger shaft  46 . In the ready to insert arrangement of the device shown in  FIG. 2 , tabs  76  are disposed in abutting engagement with the distal edge of openings  78 , resulting in the button  72  protruding partially out of plunger hollow  45 , whereby the distal face of button  72  is positioned slightly distally of distal face  44  of plunger  40 . To trigger needle insertion, button  72  is plunged proximally relative to plunger shaft  46  and housing  22 . After button  72  is so plunged, and as shown in  FIG. 3 , tabs  76  are disposed adjacent with the proximal edge of openings  78 , such that button  72  fits within plunger hollow  45  with its distal face in substantially coplanar relationship with plunger distal face  44 . To keep trigger  70  from floating within plunger  40  both before and after trigger plunging, suitable locating mechanisms, such as indents and corresponding detents on such elements, may be provided. 
         [0025]    A lock sleeve  80  made of plastic is disposed within body hollow  38  between the interior surface of body  30  and the exterior surface of plunger shaft  46 . Lock sleeve  80  is keyed to body  30  in a not shown manner to be axially fixed within body  30 , but to be rotatable in body  30  within an angular range required to unlock an insertion sleeve  90 . One suitable range of angular motion is about 30°. As further shown diagrammatically in  FIGS. 3 and 3A , the distal end region of lock sleeve  80  includes two diametrically opposed resilient, distally projecting fingers  82  each with a ramp  83  at a distal end. The distal face of each ramp  83  is inclined at  85  to facilitate its finger  82  being cammed outward by plunger shaft  46  when shaft  46  is plunged proximally to cause an injection. Although two fingers, and corresponding trigger tabs  76  and plunger shaft openings  78 , are shown, additional such components or as few as one of each such component, may be employed within the scope of the present invention. 
         [0026]    Each ramp  83  is designed to be abutted by a trigger tab  76 . During this abutting contact, as the trigger button is manually pressed downwardly relative to handle  40  to initiate needle insertion, the downwardly moving trigger tab  76  forces lock sleeve  80  to rotate due to ramp  83  sliding under and along trigger tab  76  until a complete button plunging has occurred. For the reusable delivery device shown, the slope of the lock sleeve ramps are selected to be back drivable so as to force the trigger tabs  76 , and therefore the entire trigger, distally during reset of the device as described further below. 
         [0027]    At its proximal end, lock sleeve  80  includes at least one latching module for engaging a complementary latching module of the insertion sleeve  90  to releaseably lock the sleeves together axially when in a certain arrangement. In the shown embodiment, the latching module of lock sleeve  80  includes a pair of diametrically disposed latches  88  that depend from the proximal end of lock sleeve  80 . Latches  88  are sized and shaped to cooperate with corresponding slots  92  formed in an annular collar  94  of insertion sleeve  90 . 
         [0028]    Insertion sleeve  90  is molded from plastic and keyed with body  30  to be axially movable and rotatably fixed relative thereto. Slots  92  are arcuate with a center of curvature along the central axis of the device. Slots  92  are shaped to have collar  94  be axially secured by latches  88  when sleeves  80  and  90  are in a first relative rotational arrangement, and to have collars  94  not be axially secured by latches  88  when sleeves  80  and  90  are in a second relative rotational arrangement. Although not shown in the figures, the distal face of collar  94 , for the reloadable delivery device shown, is provided with camming members that engage the lock sleeve latches  88  so as to cause appropriate rotation of the lock sleeve during apparatus reset to reengage the latching connection between the lock sleeve and insertion collar. 
         [0029]    The region of insertion sleeve collar  94  radially inward of slots  92  serves as a stop face for abutting contact with the lip  54  of plunger shaft  46 . This abutting contacts stops plunger  40  from being plunged prior to the activation of trigger  70 , which trigger activation results in insertion sleeve  90  shifting proximally, until the proximal face of sleeve  90  abuts shoulder  101  of body  30 , so as to allow a subsequent plunging of plunger  40 . The end of plunger travel during injection is also defined by abutting contact of plunger  40  with the shifted collar  94 . The region of collar  94  radially outward of slots  92  is abutted by the proximal end of a biasing member  96 , such as a metal coiled spring, that drives the needle insertion. The distal end of biasing member  96  abuts a shoulder  100  of body  30 , whereby spring  96  tends to bias insertion sleeve  90  proximally relative to housing  22 . 
         [0030]    The proximal end  102  of insertion sleeve  90  is opened and allows plunger extender  60  to pass therethrough. Proximal end  102  is sized to abut and thereby directly engage the distal, lipped end  112  of the medication containing needled syringe, generally designated  110 , to drive syringe  110  proximally through housing  22  to effect needle insertion. The interior of insertion sleeve  90  and the exterior of plunger extender  60  are complementarily configured, for example with one or more grooves and followers, such that insertion sleeve  90  drives motion of plunger extender  60  in an identical distance and direction as the proximal motion of insertion sleeve  90  relative to the housing during the spring-driven insertion sleeve advancement from the arrangement shown in  FIG. 2  during needle insertion, such that the axial space, if any, between the proximal face of plunger extender  60  and syringe piston  119  is held constant during syringe advancement. The sleeve/extender complementary configuration also allows plunger extender  60  to shift proximally relative to insertion sleeve  90 , such that the depressing of head  42  of plunger  40  to inject can drive such plunger extender portion of the plunger proximally an equal amount as the motion of head  42  to effect syringe piston advancement. 
         [0031]    Syringe  110  is of known design and includes a glass barrel  113 , an injection needle  115  projecting from the proximal end of barrel  113  and porting to the proximal end of the medicine-containing reservoir within the barrel interior volume  117 , and a piston  119  slidably and sealingly located at the distal end of the reservoir. In the shown embodiment, syringe  110  is removably mounted within a resilient washer  123  that frictionally engages the exterior periphery of glass barrel  113 . Washer  123  is sized to slide within a cylindrical hollow  125  of a plastic cup-shaped element  128  having a flared lip  130  which is fixably secured to housing needle shell  134 , as well as to a plastic cap piece  133 . A dampening spring  136  made of metal has a distal end which abuts the washer  123 , and a proximal end that abuts cap piece  133 . The shell  134 , cup element  128 , cap piece  133  and spring  136  and washer  123  together form a removable subassembly, generally designated  150 , in the shown embodiment. A projecting collar  138  of cap piece  133  is disposed inward of spring  136  and slidably accommodates glass barrel  113  to maintain the axial orientation of syringe  110  during needle insertion. The exterior periphery of cup  128  includes a circumferential recess  140  that is engaged by circumferentially spaced ribs  142  on the radially inward facing surface of body  30 . Recess  140  and ribs  142  allow for a snap fit attachment of subassembly  150  to body  30 , which attachment can be overcome for syringe replacement. Other forms of attachment, such as a screw type connection, alternatively may be employed. 
         [0032]    As the shown delivery device  20  is to be reusable with, for example, replacement syringes, a plunger reset feature is provided, such as the reset collar assembly abstractly shown at  120 . Reset collar  120  is mounted within housing body  30  to be axially and at least partially rotatably shiftable therein. When a user removes from housing body  30  the subassembly  150  and its held syringe  100  after an injection is complete, reset collar  120  is biased by a not shown spring of the assembly to a more proximal position within body  30 , such as along a track/follower connection therebetween. During such proximal motion, or as caused by a spring force after such proximal motion is completed, the reset collar rotates relative to insertion sleeve  90 . During such rotation, a not shown portion of the collar assembly  120 , acting through, for example, an opening or slot provided in insertion sleeve  90 , deactivates the latching of plunger extender  60  with plunger portion  50 , thereby allowing reset spring  56  to automatically shift plunger extender  60  distally into bore  52 . At the angular orientation resulting from this rotation, reset collar  120  engages insertion sleeve  90 , via a not shown connection on its interior and on the exterior  104  of insertion sleeve  90 . After a replacement syringe is installed in subassembly  150 , such as by overcoming the friction fit of the existing syringe barrel with washer  123 , removing the spent syringe, and then inserting a new syringe into frictional engagement with washer  123 , the device is configured as shown in  FIG. 5  Then, when subassembly  150  with its new syringe  110  is initially inserted distally into the proximal end of body  30 , cup element  128  drivingly abuts the distal face of collar assembly  120 , which in turn drivingly engages insertion sleeve  90 . As the syringe and subassembly continue to be manually driven distally relative to body  30 , reset collar  120  shifts insertion sleeve  90  distally until lock sleeve  80 , due to its rotation forced by interaction with insertion sleeve  90 , relatches with insertion sleeve  90 . This rotation of lock sleeve  80 , due to the interaction between tabs  76  and ramps  83 , causes trigger  70  to reset distally within plunger  40 . To further ensure trigger reset, the trigger may be provided with a spring biasing distally relative to the plunger shaft, which spring bias serves to shift the trigger distally when the previously plunged trigger is freed from, for example, its detent/indent connection to the plunger by a dedicated portion of the lock sleeve, at the start of lock sleeve rotation, camming a portion of the trigger other than its tab. When reset collar  120  has been shifted sufficiently to relatch insertion sleeve  90  with lock sleeve  80 , reset collar  120  has been rotated, or is biased to rotate, relative to insertion sleeve  90  to an angular orientation allowing proximal motion of sleeve  90  relative to the collar assembly  120  during needle insertion. At such time, delivery device  20  is once again configured as shown in  FIGS. 1 and 2  in a ready to insert orientation. 
         [0033]    In an alternate embodiment, rather than having a reusable syringe mounting subassembly that is snap attached to a reusable body as described above, the reusable body of  FIGS. 1-5  may be adapted to load disposable, syringe-equipped subassemblies from, and then back to after use, a protective storage container as is known in the art. 
         [0034]    While this invention has been shown and described as having preferred designs, the present invention may be modified within the spirit and scope of this disclosure. For example, in an alternate embodiment, to prevent the plunger  40  from being plunged prior to the trigger  70  being actuated, and instead of the plunger physically abutting the distal face of the insertion sleeve to provide such prevention as shown, a plunger locking may be performed by a tab of the plunger that engages the lock sleeve, which locking engagement is deactivated during the rotation of the lock sleeve associated with trigger operation. This application is therefore intended to cover any variations, uses or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.