Abstract:
Embodiments of the present invention include a device comprising a substantially planar housing defining a reservoir; a plunger disposed at least partially within said reservoir and movable between a first position and a second position; a liquid dispensing needle coupled to said plunger, said needle comprising a channel in fluid communication with said reservoir, said needle contained within said housing when said plunger is in said first position; and a spring adapted to resist movement of said plunger. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. This abstract is submitted with the understanding that it will not be used to interpret or limit the scope of the invention.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is a continuation-in-part of, claims priority to, and incorporates by reference herein in its entirety, U.S. patent application Ser. No. 09/907,609, entitled “Medical Injector,” filed Jul. 19, 2001, now U.S. Pat. No. 6,530,904. 

   BRIEF DESCRIPTION OF THE DRAWINGS 
   The invention and its wide variety of potential embodiments will be more readily understood through the following detailed description of certain exemplary embodiments, with reference to the accompanying drawings, in which: 

   
       FIG. 1  is a perspective view of an exemplary embodiment of a medical injector according to the present invention; 
       FIG. 2  is a side elevation view of the medical injector of  FIG. 1 ; 
       FIG. 3  is a sectional view taken along line  3 - 3  of  FIG. 2 ; 
       FIG. 4  is a sectional view taken along line  4 - 4  of  FIG. 3 ; 
       FIG. 5  is an enlarged sectional view of actuator elements and leaf springs, taken along line  5 - 5  of  FIG. 3 ; 
       FIG. 6  is a side elevation view of the bottom portion of the medical injector of  FIG. 1  wherein a needle portion projects from the bottom wall of a lower casing portion; and 
       FIG. 7  is an exploded view of an exemplary medical injector apparatus, showing a first casing side, a central housing member and a second casing side, which are secured together to form the medical injector apparatus housing. 
   

   DETAILED DESCRIPTION 
   Certain embodiments of the present invention relate to medical injectors suitable for use with medication that must be injected. Certain embodiments of the present invention relate to a disposable credit card sized injector, suitable for carrying in a wallet or pocket. 
   Certain embodiments of the present invention comprise a convenient medical injector that can be easy to carry and safe to use, and that can be carried in a pocket or even in a wallet of a user. 
   Certain embodiments of the present invention comprise a medical injector that can be useful for carrying pharmaceuticals including, but not limited to, epinephrine, insulin medication, anti-nerve agent, snake bite anti-venom, heart medications, allergy medication, and/or various emergency medications such as atropine, lidocaine, and/or morphine. 
   Certain embodiments of the present invention comprise a medical injector that can include a safety guard, a housing formed of a first casing portion secured to a second casing portion. A pair of hinge portions can provide pivoting motion of a safety guard. A window can be provided to observe the medication fluid stored within the wedge shaped reservoir. The safety guard can protect a pusher bar from accidental actuation. 
   The pusher bar need not be attached to the housing, and can be free to move relative thereto. The pusher bar can be connected to a column that can pass through an aperture in the stationary bar. The column can be connected directly to a wedge-shaped member that can carry a needle. 
   A spring means can be disposed between the stationary bar and the pusher bar to resiliently bias the pusher bar into a non-dispensing condition. The wedge-shaped member can be shaped to conform to a wedge-shaped recess formed in the lower casing portion, and the medication fluid can be disposed in the space between the wedge-shaped member and the lower inclined portion of the housing. This space can be a precisely defined volume, containing a precise amount of the medication fluid. 
   A resilient sleeve can be disposed in a bore formed in the bottom portion of the housing for protecting a needle. The needle can be fixed into the wedge-shaped member. The needle can pass through the rubber or plastic sleeve when the pusher bar is depressed to cause movement of the wedge-shaped member. When the pusher bar is depressed, the needle can penetrate through the resilient sleeve, and can extend beyond the bottom portion of the housing. 
   An exemplary embodiment of a medical injector apparatus  100  is shown in  FIGS. 1-7 . As shown in  FIG. 1 , the medical injector apparatus  100  includes a housing  18  having a first casing portion  20 , and a second casing portion  30 . The first casing portion  20  and the second casing portion  30  are sealed together by any known leak-proof means, such as with adhesive, by heat sealing, by laser bonding, by ultrasonic welding, and/or by fusing, etc. A chamber  28  is formed between the first casing portion  20  and the second casing portion  30 , as shown in  FIG. 3 . 
   A wedge shaped member or plunger  60  having inclined sides  61 ,  61  is slidably received within the chamber  28 . Although plunger  60  is referred to herein as “wedge shaped member  60 ” and can have wedge-shaped projection when viewed in a longitudinal cross-section, other embodiments of plunger  60  can have other projections, such as for example, flat, concave, convex, curvilinear, and/or oblique projections. The wedge shaped member  60  may be made of a resilient material, such as rubber, to provide a sliding seal between the interior walls  29  of first casing portion  20  and the second casing portion  30 . Alternately, a flexible seal  26  may be secured to the wedge shaped member  60  to provide a sliding liquid tight seal between the wedge shaped member  60  and the interior walls  29  of the chamber  28 . A fluid tight seal may also be formed between the column  24  and the stationary bar  23 . In an alternative embodiment, any “seal” described herein is not fluid tight, but can leak a relatively small amount of fluid. 
   A safety guard  10  is pivotally mounted to the housing with a pair of hinge portions  12 ,  12 . The hinge portions  12 ,  12  provide a pivoting motion of the safety guard  10  about an axis which connects the hinge portions  12 ,  12 . In certain embodiments, hinge portions  12 ,  12  can be removable from protrusions aligned with that axis and about which hinge portions  12 ,  12  allow safety guard  10  to rotate. Thus, in certain embodiments, safety guard  10  can be removable from housing  18 . In certain alternative embodiments, safety guard  10  can be slideably receivable over and/or slideably removable from housing  18 . 
   The first casing portion  20  preferably has a window  40  therein, which is made of a material which permits inspection of medication fluid  42  inside the medical injector  100 , but which does not permit passage of harmful rays there-through. For example, the material of the window  40  should block UV rays. The window  40  can be composed of a glass or plastic material, for example, coated on one side (the side not in contact with the medication fluid  42 ) to have a UV-blocking coating. For certain medication fluids, it is necessary to block much of the ambient light as well, and therefore the window  40  may be darkened somewhat, similarly to smoked glass. 
   Alternately, a breakable seal  41  may be used to secure the safety guard  10  to the housing  18 , in place over the pusher bar  22  in its raised position. The breakable seal  41  is broken when the safety guard  10  is biased about hinge portions  12 , 12  to expose the pusher bar  22 , indicating that the medical injector apparatus  100  has been used, and should be discarded after use. 
     FIG. 2  shows the medical injector apparatus  100  of  FIG. 1  in a side elevational view. This view also shows the medical injector  100  having the safety guard  10  secured to the housing  18  with opposing hinge portion  12 . 
     FIG. 3  is a sectional view of the medical injector apparatus  100 , taken along line  3 - 3  of  FIG. 2 . In this view, the wedge shaped member  60 , spring means  25  and pusher bar  22  are entirely visible. As seen in  FIG. 3 , the safety guard  10  located atop the housing  18  protects a pusher bar  22  from accidentally being depressed. The pusher bar  22  is not attached to the housing  18 , however, and is free to slidably move between the first casing side  20  and the second casing side  30 , against the biasing force of the spring means  25 . The spring means  25  may be any known spring means  25 , such as a leaf spring, resilient sponge material, coil spring, resilient tab, etc., and all such spring means are intended to be included within the scope of this invention, and the following claims. 
   The pusher bar  22  is connected to a column  24  which passes through an aperture (such as a bore) in the stationary bar  23 . The stationary bar  23  is thus not moved by actuation of the pusher bar  22 . The column  24  is connected at one end to the pusher bar  22 , and at the opposite end directly to the wedge-shaped member  60 . The pusher bar  22 , column  24 , and the wedge-shaped member  60  therefore move together as a unit when the pusher bar  22  is pushed in a dispensing direction. 
   A spring means  25  is preferably disposed between the stationary bar  23  and the pusher bar  22 , to resiliently bias the pusher bar  22  away from the fluid  42 , so as to be in a non-dispensing condition. The wedge-shaped member  60  has inclined sides  61  shaped to conform to the inclined sides  31  of the lower casing  30 . The wedge-shaped member  60  may be inclined to allow a small amount of medication to remain in the wedge shaped reservoir  62  when the wedge shaped member  60  is fully depressed, ensuring that air is not injected when the wedge shaped member  60  is fully depressed. The wedge-shaped reservoir  62  is formed within the chamber  28  formed between the first casing side  20 , the second casing side  30 , the inclined sides  61  of the wedge shaped member  60 , and the inclined sides  31  of the lower casing portion  30 . The medication fluid  42  is disposed within the wedge shaped reservoir  62  formed between the wedge-shaped member  60  and the housing  18 . This space is thus a precisely defined volume, containing a precise amount of the medication fluid  42 . Although reservoir  62  is referred to herein as “wedge shaped” and can have wedge-shaped projection when viewed in a longitudinal cross-section, other embodiments of reservoir  62  can have other projections, such as for example, flat, concave, convex, curvilinear, and/or oblique projections. 
   The bottom portion  34  of the housing  18  also includes a bore  35  extending between the chamber  28  and the bottom portion of the housing  34 . The bore  35  is sized to closely receive a resilient sleeve  33  therein. The resilient sleeve  33  is preferably made of rubber or plastic. The resilient sleeve  33  includes a top flange  36 , side walls  37  sized to slidably receive the needle  70 , and a bottom portion for sealing the needle  70  therein. The needle  70  is secured into the wedge-shaped member  60 . The needle  70  passes through the bottom portion  34  of the resilient sleeve  33  when the pusher bar  22  is depressed. This advances the needle beyond the bottom portion  34  of the housing  18 , exposing the needle tip  74  for injection of the medication fluid  42 , into a user. When the pusher bar  22  is released, the biasing means  25 , such as a spring, raises the pusher bar  22 , which in turn raises the wedge shaped member  60 , which also raises the needle into the protective custody of the resilient sleeve  33 . 
   The needle  70  includes a needle aperture  72  to pass medication fluid  42  into the needle  70  as the wedge shaped member  60  is depressed. The needle aperture  72  is exposed to the medication fluid  42  within the wedge shaped reservoir  62 , to permit flow of the fluid  42  through the needle aperture  72 , and out through the needle tip  74  when the pusher bar  22  is depressed. For example, the needle  70  can have a slit aperture  72  extending longitudinally, so that even though the needle  70  slit aperture  72  passes partially into the resilient sleeve  33 , the needle  70  can continue to receive the fluid  42 , as the wedge shaped member  60  is depressed towards the bottom portion  34  of the housing  18 . Depression of the pusher bar  22  extends the needle tip  74  beyond the bottom portion  34  of the housing  18  where the needle tip  74  is subsequently injected into the user. 
   The needle  70 , in its retracted position shown in  FIG. 3 , is preferably slightly shorter than the length of the resilient sleeve  33 , so that the needle tip  74  which would be otherwise exposed to the ambient air is instead preferably sealed within the resilient sleeve  33 , which may be very snug and self-sealing in the absence of applied pressure on the pusher bar  22 . 
     FIG. 4  is a sectional view taken along line  4 - 4  of  FIG. 3 , showing the needle tip  74  contained within the resilient sleeve  33 . In  FIG. 6 , the needle tip  74  has been actuated so that it projects from the bottom portion  34  of the housing  18 . The wedge-shaped member  60  is depressed until the inclined sides  61  abut the inclined sides  31  of the lower casing  30 , dispensing a fixed quantity of medication fluid  42  from the wedge shaped reservoir  62  through the needle tip  74  into the user. As previously noted, the inclined sides  61  of the wedge shaped member  60  may be slightly modified to allow some medication to remain in the wedge shaped reservoir  62  when the pusher bar  23  is fully depressed. This ensures that air will not be inadvertently injected with the medication. 
   To use, the bottom portion  34  of the medical injector apparatus  100  is placed against the user at the desired injection location, breakable seal  41  is removed, and the safety guard  10  is pivoted to expose the pusher bar  22 , and the pusher bar  22  is depressed to lower the needle tip  74  beyond the bottom portion  34  of the housing  18 . The medication fluid  42  from within the wedge shaped reservoir  62  is forced through the aperture  72  in the needle  70  by the wedge shaped member  60 , as the pusher bar  22  is depressed. This may be done directly against the user&#39;s skin, or directly through the user&#39;s clothing. This avoids the embarrassment of exposing the user&#39;s skin at the time of the injection, which is helpful when others are present at the time of the injection. There is a positive tactile feel, when the inclined sides  61  of the wedge shaped member  60  abut the inclined sides  31  of the lower casing  30 . 
   Once the injection has been completed, the pusher bar is released, allowing the spring means  25  to safely reposition the needle tip  74  within the resilient sleeve  33 . The safety guard  10  is then pivoted over the pusher bar  22  about hinge portions  12 ,  12  and secured into place, preventing accidental or inadvertent contact with the needle tip  74  during disposal of the medical injector apparatus  100 . The medical injector apparatus  100  disclosed herein is intended to be used once, then discarded, for safety and to avoid possible contamination with a used needle  70 . 
   The wedge-shaped member  60  is movable relative to the housing  18 , despite the relatively tight fit, which is necessarily tight in order to form a fluid-tight seal between the wedge-shaped member  60  and the interior walls  29  of the housing  18 . A resilient seal  76  may be used between the stationary bar  23  and the wedge shaped member  60  to aid in sealing the medication fluid  42  within the wedge shaped reservoir  62 . 
     FIG. 5  is an enlarged sectional view of the pusher bar  22 , column  24 , the stationary bar  23 , and at least one spring means  25 , taken along line  5 - 5  of  FIG. 3 . As seen, column  24  passes through a column aperture  21  in the stationary bar  23 . The spring means  25  is preferably disposed on both sides of the column  24 , so that, when pressure on the pusher bar  22  is released, the pusher bar  22  is raised, thereby retracting the needle  70  into the housing  18 . Thus, the medical injector apparatus  100 , once used, presents no accidental sharps hazard during disposal of the medical injector apparatus  100 . 
     FIG. 6  is a side elevational view of the bottom portion  34  of the housing  18  of the medical injector apparatus  100  of  FIG. 1 . In  FIG. 6 , the needle tip  74  is shown in its fully extended position, with the needle tip  74  projecting from the bottom portion  34  of the housing  18 . As soon as pressure on the pusher bar  22  is released, the needle tip  74  is retracted into the housing  18 , ensuring safe disposal of the medical injector apparatus  100  after use. 
   As seen in  FIG. 1 , the first casing  20  preferably has a window  40  therein, at a location in alignment with the medication fluid  42  when the pusher bar  22  is not depressed. Thus, the window  40  permits the medication fluid  42  to be viewed through the window  40 , enabling the user to determine if the medication fluid  42  has been previously dispensed. The window  40  also permits the user to see if the medication fluid  42  has changed color, or evaporated. Preferably, the window  40  is treated to provide UV resistance, when light sensitive or UV sensitive medication fluid  42  is placed within the medical injector apparatus  100 . 
   A seal means  41  may be secured between the safety guard  10  and the housing  18 . The seal means  41  is used to secure the safety guard  10  in place over the pusher bar  22 , in its raised position. The seal means  41  is broken, biased or removed to enable the safety guard  10  to pivot about hinge portions  12 , 12  to expose the pusher bar  22 . When the seal means  41  is broken, biased or removed, it is apparent that the medical injector apparatus  100  has been used, and should not be reused. When the safety guard  10  is returned to its protective position over the pusher bar  22 , there is no danger of accidentally or inadvertently depressing the pusher bar  22 . This ensures that the needle  70  will remain above the lower casing  30 . The seal means  41  may be any known type seal, such as an adhesive strip used to secure medication within a container, prior to use. 
   The safety guard  10  can be adapted to snap lock in place in a manner well known in the art to further protect the pusher bar  22  from being accidentally depressed after use. 
   The length and width of the housing  18  is preferably sized to be similar to the length and width of a credit card (not shown), and the thickness of the housing  18  is sized to be less than one inch, for ease of transport and storage. 
   The housing  18  may be adapted to comprise a central housing member  80 , with the central housing member  80  shaped to provide a wedge shaped reservoir  62  located beneath a stationary bar  23 , as shown in  FIG. 7 . In this adaptation, the first casing side  20  is secured to a one side of the central housing member  80 , and the second casing side  30  secured to the opposite side of the central housing member  80 . The first and second casing sides  20 ,  30  enclosing the wedge shaped reservoir  62  therebetween. 
   Indicia  78  is positioned on at least one of the first casing side  20  and the second casing side  30 . The indicia  78  preferably includes information relating to the type of medication fluid  42  stored within the medical injector apparatus  100 , and instructions relating to the use and disposal of the medical injector apparatus  100 . 
   The invention being thus described in the form of a preferred embodiment, it will be evident that the invention may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention and all such modifications are intended to be included within the scope of the claims.