Abstract:
A needle-free injector for injecting fluid from an injection cartridge that has a longitudinal axis, an injection orifice at a distal end and a displaceable plunger. The needle-free injector includes an injector body having a longitudinal axis and a side opening to receive the cartridge from a position laterally offset from the injector body longitudinal axis. The needle-free injector further includes a system disposed in the injector body for providing injection power and a ram for transferring power from the system to the plunger. The ram is disposed in the injector body and is axially aligned with the longitudinal axis of the cartridge when the cartridge is in position in the injector body. The needle-free injector further includes a closure mechanism for closing the side opening of the injector body after the cartridge is in position in the injector body to lock the cartridge in place in the injector body. The disclosure also includes other apparatus and methods as discussed in detail herein.

Description:
[0001]     This application is also a continuation-in-part of U.S. patent application Ser. No. 10/976,342 filed Oct. 26, 2004 and also claims the benefit of U.S. provisional patent application No. ______ filed Feb. 15, 2005 under Express Mail No. EV493217799US entitled Needle-Free Injection Device for Individual Users, which is hereby incorporated by reference in its entirety for all purposes. 
     
    
     BACKGROUND  
       [0002]     Needle-free injection systems provide an alternative to standard fluid delivery systems, which typically uses a needle adapted to penetrate the outer surface of an injection site. Typically, needle-free injection systems are designed to eject the fluid from a fluid chamber with sufficient pressure to allow the fluid to penetrate the target to the desired degree. For example, common applications for needle-free injection systems include delivering intradermal, subcutaneous and intramuscular injections into or through a recipient&#39;s skin. For each of these applications, the fluid must be ejected from the system with sufficient pressure to allow the fluid to penetrate the tough exterior dermal layers of the recipient&#39;s skin.  
         [0003]     When using the same device to deliver inoculations, immunizations or the like, to different individuals, preventing cross-contamination between injection recipients and prevention of contamination of the filling source must be a priority. Thus, it is desirable to provide a device that allows a user to move with reasonable speed from one injection recipient to another while maintaining adequate protections against cross-contamination. In addition, it will often be desirable to obtain the above advantages while also keeping waste to a minimum (e.g., by avoiding unnecessary disposal of portions of the injection system).  
         [0004]     It is also desirable in many applications that an injector be relatively small, hand-held, and ergonomically comfortable so that it can be easily handled by the health care provider. When a spring loaded injector is being used, it is also desirable that the injector spring be easily compressed. These and other advantages of the preferred embodiments will be apparent as this description continues.  
       SUMMARY  
       [0005]     A needle-free injector is provided for injecting fluid from an injection cartridge that has a longitudinal axis, an injection orifice at a distal end and a displaceable plunger. The injector also includes an injector body having a longitudinal axis and a side opening to receive the cartridge from a position laterally offset from the injector body longitudinal axis. A closure mechanism is included for closing the side opening of the injector body after the cartridge is in position in the injector body with the longitudinal axes of the cartridge and the injector body coincident in order to lock the cartridge in place in the injector body.  
         [0006]     Another aspect of the invention is a method for loading an injection cartridge into a needle-free injector, including the following steps: selecting an injection cartridge that has a longitudinal axis; selecting an injector body that has a longitudinal axis, a side opening and a closure mechanism for selectively closing the side opening; opening the closure mechanism of the injector body; moving the injector cartridge laterally from a position that is laterally offset from the longitudinal axis of the injector body through the side opening of the injector body into position in the injector body with the longitudinal axes of the injector body and the cartridge in alignment; and closing the side opening of the injector body to lock the cartridge in place in the injector body.  
         [0007]     The invention alternatively provides a spring-loaded needle-free injector having an injector body, a main spring, and a winder that is rotatable in either the first direction or a second direction, and which can compress the main spring by rotating in the first direction. Also included is a ratchet mechanism in the form of a first and a second toothed member with at least one of the members being spring biased toward the other member, the ratchet mechanism being interconnected with the winder so that winding the winder in the first direction causes both toothed members to rotate, but winding the winder in the second direction causes rotation of only the first toothed member.  
         [0008]     Yet another aspect of the invention is a method for compressing the spring of a spring-loaded needle-free injector which includes the steps of selecting an injector body having a main spring, a winder that is rotatable in either a first direction or a second direction and which compresses the main spring by rotating in the first direction, and a ratchet mechanism having rotatable first and second members with sloped teeth. At least one of the members is spring biased toward the other member. The ratchet mechanism is interconnected with the winder so that winding the winder in the first direction causes both toothed members to rotate but winding the winder in the second direction causes rotation of only the first toothed member. The winder is wound in the first direction, causing both of the members to rotate to compress the main spring, and then is wound in the second direction, causing only one of the members to rotate. The winder is then wound again in the first direction, causing both of the members to rotate to further compress the main spring.  
         [0009]     Another aspect of the invention is a spring-loaded needle-free injector having a main body with distal and proximal ends and a longitudinal axis. An injection cartridge is provided that is mounted to the distal end of the main body, the cartridge having a fluid chamber defined therein and an injection orifice at the distal end. A trigger sleeve is slidably mounted to the main body, and a trigger lock that prevents the trigger from sliding with respect to the main body when locked is also provided. A firing mechanism that is actuated by unlocking the trigger lock and then sliding the trigger sleeve toward the distal end of the main body is also provided to fire the injector.  
         [0010]     Yet another aspect of the invention is a method of injecting fluid from a needle-free injector that includes the following steps: selecting an injector having a main body with distal and proximal ends; slidably mounting a trigger sleeve to the main body, the trigger sleeve having the capability of actuating a firing mechanism when slid along the main body in a distal direction, the trigger sleeve having a trigger lock that can be locked and unlocked and which prevents the trigger sleeve from sliding with respect to the main body when the trigger lock is locked; mounting an injection cartridge adjacent the distal end of the main body, the cartridge including a fluid chamber defined therein and an injection orifice at the distal end thereof; and unlocking the trigger lock and sliding the trigger sleeve toward the distal end of the main body to fire the injector and cause the fluid to be ejected out of the fluid chamber and through the injection orifice.  
         [0011]     The invention could also provide a needle free injector which includes an injection cartridge with a plunger and an injection orifice, an injector body, a system for providing injection power, a ram disposed in the injector body for transferring injection power from the system to the plunger, and a frangible member mounting the ram to the plunger such that the ram and plunger can be retracted under one amount of force to fill the cartridge with fluid, and such that when the ram and plunger are driven forward under another amount of force that is greater than the one amount of force, the ram breaks the frangible member but still allows the ram and plunger to drive fluid from the cartridge through the injection orifice. Therefore, in the event someone attempts to retract the ram and plunger to re-fill the cartridge, the ram will retract but the plunger will not because the frangible member has been broken.  
         [0012]     A method for preventing the re-loading of a cartridge is also provided that includes the steps of selecting an injection cartridge having a plunger and an injection orifice, and selecting an injector body in which the cartridge can be removably mounted and having a system for providing injection power, a ram for transferring injection power from the system to the plunger, and a frangible member mounting the ram to the plunger such that the ram and plunger can be retracted under one amount of force to fill the cartridge with fluid, and when the ram and plunger are driven forward under another amount of force that is greater than the one amount of force, the ram breaks the frangible member but still allows the ram and plunger to drive fluid from the cartridge through the injection orifice. Therefore in the event someone attempts to retract the ram and plunger to re-fill the cartridge, the ram will retract but the plunger will not because the frangible member has been broken.  
         [0013]     Yet another aspect of the invention provides a spring-loaded needle free injector for injecting fluid from an injection cartridge that has an injection orifice and a displaceable plunger. Included is an injector body, a main spring for providing injection power for the injector, a ram disposed in the injector body for transferring power from the main spring to the plunger, and a cartridge loading mechanism that retracts the ram for alternatively loading injection fluid into the injection cartridge or for facilitating the loading of a pre-filled injection cartridge.  
         [0014]     A needle-free injector for injecting fluid from an injection cartridge that has a longitudinal axis, an injection orifice at a distal end and a displaceable plunger may also be provided in accordance with the invention. The injector typically includes an injector body having a longitudinal axis and a side opening to receive the cartridge from a position laterally offset from the injector body longitudinal axis. A closure mechanism is also included for closing the side opening of the injector body after the cartridge is in position in the injector body to lock the cartridge in the injector body. A ram is disposed in the injector body for transferring power from the system to the plunger, the ram being aligned with the longitudinal axis of the cartridge when the cartridge is in the injector body. A cartridge loading mechanism is normally also included that retracts the ram for alternatively loading injection fluid into the injection cartridge or for facilitating the loading of a pre-filled injection cartridge.  
         [0015]     A spring-loaded needle-free injection system is further provided that includes a nozzle having a fluid chamber therein for containing injectable fluid and an injection orifice fluidly coupled with the fluid chamber. Also included is a main spring configured to be compressed during arming of the injection device, the spring-powered injection device being configured to forcibly eject fluid from the fluid chamber out through the injection orifice during decompression of the spring. This system typically also includes a filling adapter that is frangibly attached to the nozzle such that the filling adapter cannot be reattached to the nozzle after being broken away from the nozzle. Thus, the system is configured to prevent delivery of an injection from the injection orifice into an injection site until the filling adapter is broken away from the nozzle.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]      FIG. 1  is a perspective view of a first embodiment of the present invention after the cartridge has been inserted in the injector but before the cartridge is locked in position.  
         [0017]      FIG. 2  is a perspective view corresponding to  FIG. 1  except that the cartridge has been locked into position.  
         [0018]      FIG. 3  is a perspective view corresponding to  FIG. 1  except that the trigger sleeve has not yet been slid forwardly as the injector is pressed against the patient.  
         [0019]      FIG. 4  is an end view of the first embodiment.  
         [0020]      FIG. 5  is an exploded view of the first embodiment.  
         [0021]      FIG. 5A  is an enlarged perspective view of the ratchet rings of the first embodiment.  
         [0022]      FIG. 6  is a side elevation sectional view of the first embodiment before compression of the main spring begins.  
         [0023]      FIG. 6A  is a fragmentary side elevation sectional view of the first embodiment after the main spring has been loaded.  
         [0024]      FIG. 6B  is a fragmentary side elevation sectional view of the first embodiment after the main spring has been loaded, and after the trigger sleeve has slid forward to fire but in the instant before firing takes place.  
         [0025]      FIG. 6C  is a fragmentary side elevation view of the first embodiment after the injector has been fired (corresponding to  FIG. 6 ).  
         [0026]      FIG. 7  is a side elevation sectional view of the first embodiment after the main spring has been compressed but before the nozzle has been filled with injection fluid.  
         [0027]      FIG. 8A  is a side elevation sectional view of the first embodiment after the main spring has been compressed and after the nozzle has been filled with injection fluid.  
         [0028]      FIG. 8B  is a side elevation sectional view corresponding to  FIG. 8A  except that section is 90° offset.  
         [0029]      FIG. 9  is a side elevation sectional view of a second embodiment before compression of the main spring.  
         [0030]      FIG. 10A  is a side elevation sectional view of the second embodiment after compression of the main spring and after the nozzle has been filed with injection fluid.  
         [0031]      FIG. 10B  is a side elevation sectional view corresponding to  FIG. 10B  except that the section is 90° offset.  
         [0032]      FIG. 11  is a side elevation sectional view of the second embodiment after compression of the main spring but before the nozzle has been filled with injection fluid.  
         [0033]      FIG. 12  is a side elevation sectional view of the winder portion at the proximal end of the first embodiment.  
         [0034]      FIG. 13  is a fragmentary side elevation sectional view of a third embodiment.  
         [0035]      FIG. 14  is a fragmentary perspective view of the plunger with ram portion of the third embodiment showing the frangible member broken to prevent re-use.  
         [0036]      FIG. 15  is a fragmentary perspective view of the plunger/ram portion of the third embodiment, prior to the point at which the frangible member is broken.  
         [0037]      FIG. 16  is a fragmentary perspective view of the plunger and the ram of the third embodiment showing that when the plunger is withdrawn after the frangible member is broken, the plunger does not follow.  
         [0038]      FIG. 17  is a perspective view of the plunger of the third embodiment showing the frangible member intact.  
         [0039]      FIG. 18  is an exploded isometric view showing alternate embodiments of a vial adapter and nozzle/filling assembly according to the present description.  
         [0040]      FIG. 19  is a sectional view depicting operative engagement of the vial adapter and nozzle/filling assembly of  FIG. 18 , so as to enable a dose of injectable fluid from an external supply (e.g., a vial) to be loaded into the injection device.  
         [0041]      FIG. 20  depicts a non-compliant attempt to fill the nozzle/filling assembly of  FIGS. 18 and 19  after detachment of the filling adapter.  
         [0042]      FIG. 21  is a partial sectional view depicting a further alternate embodiment of a vial adapter and nozzle/filling assembly according to the present description.  
         [0043]      FIG. 22  is an exploded isometric view showing another alternate embodiment of a vial adapter according to the present description.  
         [0044]      FIG. 23  depicts the vial adapter of  FIG. 22  operatively engaged with an alternate nozzle/filling assembly according to the present description.  
         [0045]      FIG. 24  is an exploded view of yet another embodiment to be used with a prefilled cartridge.  
         [0046]      FIG. 25  is a side elevation sectional view of the embodiment of  FIG. 24  after a new, prefilled cartridge has been mounted in place.  
         [0047]      FIG. 26  is a side elevation sectional view of the embodiment of  FIG. 24  after the injector has been fired.  
         [0048]      FIG. 27  has a side elevation sectional view of the embodiment of  FIG. 24  after the ram extension has been withdrawn and the cartridge is ready to be removed and replaced. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0049]      FIGS. 1-27  depict various embodiments of a spring-loaded needle-free injection device. As will be explained in more detail below, the device typically is implemented as a single-use injection system including a fluid cartridge that may be engaged with an injector mechanism such as that depicted in the figures. A fluid chamber within a nozzle/cartridge may be filled with a dose of injectable fluid. Typically, filling is accomplished from an external supply of fluid, which may include a vial adaptor that allows the external supply to be selectively coupled to the nozzle-cartridge filling assembly. After filling, the external supply of fluid is decoupled from the nozzle/cartridge filling assembly by simply removing the external supply and vial adaptor from engagement with the nozzle/cartridge assembly.  
       Embodiment of FIGS.  1 - 8  and  12   
       [0050]     Before describing the operation of the depicted system, the various parts and their relationship to one another will first be described. A first embodiment of the injector system is depicted at  10  in  FIGS. 1-8  and  12 . For an identification and description of the various parts, reference should first be made to  FIGS. 5 and 6 - 8 . The basic components of injector  10  are a main body  12  (see  FIG. 5 ), a trigger sleeve  14 , a winder  16 , a cartridge  20  and a cartridge lock  22 . Trigger sleeve  14  is designed to slideably fit over main body  12 . Winder  16  is rotatably mounted to trigger sleeve  14  such that a spring may be compressed to provide power for the injection. Winder  16  is located at a proximal end of injector  10 , which is opposite the end to which cartridge  20  is mounted.  
         [0051]     Beginning at the proximal end of injector  10 , a dosage knob  24  is included. Dosage knob  24  includes fine, left-handed threads  26  which engage complementing fine threads  28  in a dosage drum  30 . A dosage spring  32  is positioned within dosage knob  24  and dosage drum  30  and extends between the proximal end of the dosage knob and a dosage spring seat  34 . Positioned within dosage spring  32  is a slide bushing extension  36  and a slide bushing extension seat  38 . Slide bushing extension  36  and slide bushing seat  38  mount to and extend the length of a slide bushing  88 , which will be described in more detail below.  
         [0052]     Positioned around dosage spring  32  within the proximal end of injector  10  is an enlarged ratchet spring  40  which is designed to bias a second ratchet ring  42  toward a first ratchet ring  44 . The first and second ratchet rings each include a plurality of teeth  45  and  43 , respectively (see  FIG. 5A ), that are designed to permit relative rotation in one direction but not another. The teeth can be seen to be tilted to one side or sloped to facilitate this sliding in one direction and engagement in the other direction. Therefore, when winder  16  causes second ratchet ring  42  to rotate in a clockwise direction, the spring bias provided by ratchet ring  40  causes teeth  45  and  43  to engage and thereby rotate first ratchet ring  44  in that first direction. However, when winder  16  is rotated in a counterclockwise direction, teeth  45  and  43  of first and second ratchet rings  44  and  42  are permitted to slide over one another  
         [0053]     A pair of small winder pins  46  are positioned within second ratchet ring slots  47  and winder slots  48  so that when the two ratchet rings are positioned within winder  16 , relative rotation is not permitted between the second ratchet ring and the winder.  
         [0054]     As seen best in  FIGS. 5 and 12 , a pair of long pins  50 , each having a head at its proximal end, are positioned within notches  52  in the outer diameter of first ratchet ring  44 , and extend through a pair of diametrically opposed holes  54  in dosage drum  30 . Long pins  50  extend in a distal direction past dosage spring seat  34 , nut  56 , washer  58 , and engage notches  68  in the outer diameter of a torque nut  60 . A pair of dosage screw pins  64  extend between notches  66  in the inner diameter of torque nut  60  and a dosage screw  62 . Thus, dosage screw pins  64  prevent relative rotation between torque nut  60  and dosage screw  62 . Because long pins  50  prevent relative rotation between first ratchet ring  44 , dosage drum  30  and torque nut  60 , relative rotation is not permitted between first ratchet ring  44  and dosage screw  62 , for reasons that will become apparent as this description continues.  
         [0055]     A pair of so-called clam shell halves  70  are mounted between dosage drum  30  and trigger sleeve  14  to prevent axial displacement between these two components, but permit relative rotation therebetween. Clam shell halves  70  are held together by a pair of clam shell screws  72 . Clam shell halves  70  are engaged with trigger sleeve  14  by a pair of clam shell pins  74 . The only engagement between clam shell halves  70  and dosage drum  30  is the engagement of a proximal leg  71  of the substantially U-shaped clam shell halves. That is, proximal leg  71  engages a complementing slot  73  in dosage drum  30 . Thus, again, the dosage drum, winder and associated parts are held in engagement with the trigger sleeve, but relative rotation is permitted between them so that the winder can be rotated to compress a main spring  102 , as will be understood as this description continues.  
         [0056]     Continuing in a distal direction, a pair of trigger locks  76  are pivotally mounted to trigger sleeve  14  by trigger lock pivot points  78 . Trigger locks  76  each include radially-extending trigger lock legs  80  that engage a ledge or notch  82  in main body  12 . Each of the trigger locks  76  includes a trigger lock spring  84  that pushes the distal end of the trigger locks outwardly, thereby causing trigger lock legs  80  to engage notch  82  until the trigger locks are depressed against the outward bias of the trigger lock springs. In most applications only a single trigger lock will be included even though two such trigger locks are included in the depicted embodiment.  
         [0057]     A trigger sleeve window  86  is provided in the side of trigger sleeve  14  so that a visual indicator can be provided to ensure the proper positioning of the components prior to firing. Window  86  can also be used to provide a read-out of the dosage that is being injected.  
         [0058]     Referring again to the exploded view of  FIG. 5  and the assembled view of  FIGS. 6-8 , slide bushing  88  can be seen to extend through trigger sleeve  14  and within winder  16  to contact the distal end of slide bushing extension  36 . In some embodiments there may be a single slide bushing rather than the two-part slide bushing/slide bushing extension shown in injector  10 .  
         [0059]     A trigger spring  90  can be seen to the positioned within slide bushing  88 . Trigger spring  90  is seated in a trigger spring seat  92  which in turn is positioned within a firing sleeve  94 . Four hardened steel balls  96  are initially positioned within four ball seats  98  in firing sleeve  94  for purposes that will become apparent as this description continues.  
         [0060]     An upper spring seat  100  provides a proximal seat for main spring  102 , which provides injection power for injector  10 . A main spring seat  104  provides a distal seat for main spring  102 . A substantially square washer  106  is shown to be positioned between main spring seat  104  and a ram  108 . As shown, main spring seat  104  includes a central opening through which ram  108  extends. A ram bolt  110  extends out of the proximal end of ram  108  to provide a hardened surface for the proximal end of ram  108 . Ram  108  includes a ram seat  112  and, at its distal end, a head  114  which is defined by a notch in the ram. The configuration of head  114  is designed to facilitate engagement of cartridge  20 .  
         [0061]     At the distal end of injector  10  is a cartridge lock  22 , which is mounted to main body  12  by a cartridge holder  118 . Specifically, external threads  120  in cartridge holder  118  engage with complementing internal threads  122  in main body  12  in order to properly engage the cartridge holder to the main body. A detent pin  128  and a small spring are provided to cause cartridge lock  22  to click into its locked position.  
         [0062]     Cartridge  20  can be seen to include a plunger  130  positioned within a chamber  132  in a nozzle  140 . The distal end of nozzle  140  includes an injection orifice  142 . Plunger  130  includes a substantially U-shaped proximal end  136 , which is designed to engage head  114  in the distal end of ram  108 . This provides a solid mount that will convey forces conveyed between the ram and the plunger and yet permits easy engagement and disengagement.  
         [0063]     Cartridge lock  22  includes a cartridge lock opening  138  ( FIGS. 1-4 ) so that the cartridge can be moved into position from one side and the U-shaped proximal end  136  of plunger  130  may be engaged with head  114  in ram  108 . A cartridge holder opening  137  is also provided so that in the cartridge insertion condition, cartridge lock opening  138  is in alignment with the cartridge holder opening. As shown in  FIGS. 1 and 2 , cartridge lock  22  is then rotated 90° with respect to the rest of injector  10  so that cartridge lock opening  138  and cartridge holder opening  137  are no longer in alignment. This effectively locks cartridge  20  in place in injector  10  for firing.  
         [0064]     Nozzle  140  may be loaded with injection fluid by the system described in my application Ser. No. 10/976,342, or any conventional system. Once nozzle  140  is loaded, the nozzle and its injection orifice  142  may be placed against the patient for injection.  
         [0065]     While the depicted embodiment is a spring-loaded embodiment, it should be understood that it is also possible to use a gas-powered injector (not shown) in connection with the depicted described system for loading a cartridge from the side. Gas-powered systems are included in U.S. Pat. Nos. 6,096,002, 6,607,510, 6,645,170, and 6,689,093, which are incorporated herein by reference.  
         [0066]      FIG. 6  depicts injector  10  in its initial position prior to filling of the nozzle  140  and prior to the point at which main spring  102  is loaded. This is also shown in  FIG. 6C . In this position it can be seen that both dosage spring  32  and main spring  102  are in their relaxed positions. Legs  80  of trigger locks  76  are in engagement with notch  82  in main body  12 . If the patient now wishes to perform an injection, the patient holds trigger sleeve  14  with one hand, normally the left, and turns winder  16  in a clockwise direction. The ratchet mechanism eases the winding process because winder  16  can merely be turned repeatedly one direction and then the other rather than having to rotate the winder entirely around. In certain applications this may be an easier operation than the complete rotation, particularly for clients who may have decreased motor skills.  
         [0067]     As winder  16  is rotated in the clockwise direction, the winder carries second ratchet ring  42 . Ratchet spring  40  holds teeth  43  of second ratchet ring  42  against teeth  45  of first ratchet ring  44 . This causes first ratchet ring  44  to rotate and along with it so rotates dosage drum  30 , torque nut  60  and dosage screw  62 . When winder  16  is ratcheted back in a counter clockwise direction, the teeth  45  and  43  of first and second ratchet rings  44  and  42 , respectively, slip across each other without causing a reverse rotation of first ratchet ring  44 , the dosage drum  30 , torque nut  60  or dosage screw  62 . As a result of this repeated back and forth rotation of winder  16 , dosage screw  62  is turned down into the injector, exerting a forward or downward force on main spring seat  104  and main spring  102  positioned therebelow. This compresses main spring  102  for the injection operation. As the compression of main spring  102  is completed, trigger spring seat  92 , firing sleeve  94  and balls  96  move from the position shown in  FIGS. 6 and 6 C to the position shown in  FIGS. 7 and 6 A where the balls are positioned immediately below the head of ram bolt  110 .  
         [0068]     At this point, injector  10  is ready to be loaded with medication, vaccine or other medicinal fluid. In order to retract the plunger and thereby draw fluid from a vial, injector  10  is held in an upright position with the vial at the top. Dosage knob  24  is then rotated in a counter clockwise direction, thereby drawing back slide bushing extension  36 , slide bushing extension seat  38 , slide bushing  88 , firing sleeve  94 , ram  108  and plunger  130 . This draws fluid into chamber  132 , thus preparing injector  10  for injection. This so-called ratchet-ready position is depicted in  FIGS. 8A and 8B .  
         [0069]     Injector  10  cannot be fired until trigger locks  76  are both depressed, or in the event only one trigger lock is included, the injector cannot be fired until that single trigger lock is depressed. This provides a safety in order to prevent inadvertent firing. To fire injector  10  and inject fluid into the patient, trigger locks  76  are depressed, thereby releasing the engagement between trigger lock legs  80  and notch  82  in main body  12 . This is done after orifice  142  of nozzle  140  is pressed against the skin of the patient receiving the injection. Thus, with the trigger locks depressed, injector  10  is pressed against the patient, causing trigger sleeve  14  to slide in a forward direction toward the patient to the position shown in  FIG. 7 . This causes balls  96  to shift outwardly to the position shown in  FIG. 6B . This  FIG. 6B  shows a disposition of parts that will be only momentary, that is, immediately after balls  96  clear the head of ram bolt  110 . Ram  108  will quickly shoot forward, causing plunger  130  to drive fluid in chamber  132  out of orifice  142  and through the skin of the patient.  
         [0070]     After the injection process is completed, trigger sleeve  14  is slid back to its original position by spring  32  so that trigger lock legs  80  engage notch  82  of main body, and cartridge lock  22  is rotated to permit sideways removal of nozzle  140 . When injector  10  is to be reused, another nozzle is loaded in place and the process is repeated.  
       Embodiment of FIGS.  9 - 11   
       [0071]     The injector of  FIGS. 9-11  is identical to the injector of  FIGS. 1-8  except that the ratchet mechanism associated with winder  16  has been deleted. Therefore, it is necessary to rotate the winder repeatedly around with respect to trigger sleeve  14  in order to cause main spring  102  to be compressed for firing. It can be seen that the first and second ratchet rings and other associated parts have been deleted from this embodiment  210 . Because the other features are typically identical to those described in connection with injector  10 , the description of the construction and operation of those other parts will not be repeated. The numbering of the parts has been maintained the same as the embodiment of  FIGS. 1-8  and  12  because those parts are typically identical in this second embodiment.  
       Embodiment of FIGS.  13 - 17   
       [0072]      FIGS. 13-17  show a slightly different version of the nozzle and ram assemblies. As noted above, it is desirable that once a cartridge or nozzle has been used, that it be disabled so that it cannot be reused. This is desirable to prevent cross-contamination between patients. In order to provide that capability in the disclosed injector  10 , the nozzle and ram assemblies may be modified as shown in  FIGS. 13-17 .  
         [0073]     Numbers corresponding to  FIGS. 1-8  and  12  are shown, except for similar parts,  100  has been added. Therefore, the nozzle has been identified at  240 , the plunger at  230 , the nozzle U-shaped proximal end at  236 , and the ram at  208 . A frangible member  216 , shown best in  FIG. 17 , is mounted to U-shaped proximal end  236  by frangible or breakable tabs  217  for purposes that will become apparent as this description continues.  
         [0074]     Instead of notched head  114  in ram  108  of injector  10 , the embodiment of  FIGS. 1-8  includes two flanges in addition to the flange that forms ram seat  212 . As shown, a small distal flange is indicated at  214 , and a middle flange is shown at  213 . As shown best in  FIG. 13 , middle flange  213  is disposed proximally of distal flange  214  and includes a shoulder  215  on its distal side.  
         [0075]     In operation, nozzle  240  is filled in the same manner as described above with respect to nozzle  140 . Ram  208  is drawn back so that distal flange  214  contacts frangible member  216 . Because the loading force is so small, perhaps as low as ten pounds or even five pounds or less, frangible member  216  will not break as plunger  230  is pulled back to draw injection fluid into chamber  232 .  
         [0076]     When the injection force is applied via ram  208 , shoulder  215  of middle flange  213  drives through frangible member  216  before distal flange  214  contacts U-shaped proximal end  236  of plunger  230 . Shoulder  215  and middle flange  213  close off enough of U-shaped proximal end  236  to prevent fragments of frangible member  216  and tabs  217  from falling out and potentially causing jamming of the various components.  
         [0077]     After firing, nozzle  240  is removed from the injector as in the previously-described embodiments. A new nozzle, with an intact frangible member  216 , is installed for the next injection. This prevents cross-contamination between patients. If, rather than replacing nozzle  240 , the user attempts to reuse and reload the nozzle, the absence of frangible member  216  will cause distal flange  214  to merely pull out of U-shaped proximal end  236  as shown in  FIG. 16 . This will prevent plunger  230  from being drawn back in chamber  232 , and a fluid-loading suction will not be created. Thus, this embodiment of the present invention provides a simple yet effective way to prevent cross-contamination and is a reason this is a preferred embodiment.  
         [0078]     As with the first embodiment discussed above, it should be understood that it is possible to use this embodiment of  FIGS. 13-17  with a gas-powered injector such as those systems described in U.S. Pat. Nos. 6,096,002, 6,607,510, 6,645,170, and 6,689,093, which are incorporated hereby reference.  
       Embodiment of FIGS.  18 - 20   
       [0079]     Another manner in which cross-contamination can be prevented is to use one of the loading vial adaptor systems described in the parent application. To avoid confusion, the numbering has been retained from the parent application.  FIGS. 18-20  depict an embodiment of a nozzle/filling assembly  280  and vial adapter  282 . Vial adapter  282  typically includes a main body  284 , an inner valve sleeve  286  and a plug  288 . Vial adapter  282  typically is attached to and carried on a multiple-dose container (e.g., vial  290 ) of injectable fluid. Nozzle/filling assembly  280  may include a nozzle  292 , a filling adapter  294  secured to the front end of the nozzle, and a piston  296  slidably disposed within a fluid chamber  298  of the nozzle.  
         [0080]     Nozzle/filling assembly  280  typically is provided to the end user in a ready-to-fill state. In this state, the nozzle/filling assembly may be operatively engaged with vial adapter  282  to perform the filling operation, in which a dose of injectable fluid is drawn from vial  290  through injection orifice  300  and into fluid chamber  298  of nozzle  292 . To allow the injection to go forward, filling adapter  294  is broken away from nozzle  292 . Filling adapter  294  is specially configured to operatively engage with vial adapter  282  to perform the filling operation. Typically, the system is configured so that filling cannot occur after filling adapter  294  is broken away. Thus, a single simple step permits the injection to go forward, while simultaneously disabling the ability to refill nozzle  292 .  
         [0081]     Main body  284  of vial adapter  282  includes a vial gripping section  310  (see  FIG. 19 ) adapted to grip a vial of injectable fluid (e.g., vial  290 ), and several fingers extending axially away from the gripping section. The extending structures may include relatively rigid fingers  320  and relatively flexible fingers  322  (see  FIG. 18 ). In the depicted embodiment, there are four rigid fingers, with a flexible finger disposed between each rigid finger, for a total of eight fingers, though it should be appreciated that different numbers of fingers may be employed in various configurations.  
         [0082]     Vial adapter  282  includes a piercing member or spike  321  configured to pierce a sealed opening of vial  290 . Openings are provided on piercing member  321  to enable injectable liquid from vial  290  to flow into a central channel  326  defined within a cylindrical member  328  extending away from gripping section  310  between fingers  320  and  322 . Plug  288  is fitted snugly into the distal end of cylindrical member  328 . As indicated in  FIGS. 18 and 19 , plug  288  includes channels  330  configured to permit fluid to be drawn out of central channel  326  and into the area around injection orifice  300  of nozzle  292 . As will be explained in more detail, inner valve sleeve  286  may be axially movable between a position in which it seals off channels  330 , and an unsealed position, in which liquid is permitted to pass out through the channels to injection orifice  300 .  
         [0083]     Referring specifically to  FIG. 19 , to fill the device, nozzle/filling assembly  280  is first inserted into and received within vial adapter  282 . Prior to this, nozzle/filling assembly  280  may first be secured within an injector device or other mechanism. As nozzle/filling assembly  280  is inserted into vial adapter  282 , a ramped portion  340  on the outer diameter of filling adapter  294  bears against flexible fingers  322 , urging them outward. Flexible fingers  322  are urged far enough outward by filling adapter  294  so that the flexible fingers are pushed beyond the outer edges of a flanged portion  342  of nozzle  292 , thereby allowing the nozzle/filling assembly to be inserted further into vial adapter  282 .  
         [0084]     Inserting nozzle/filling assembly  280  into vial adapter  282  also causes a forward end of nozzle  292  to push against the distal end of inner valve sleeve  286 . Prior to contact with nozzle  292 , inner valve sleeve  286  is biased axially away the vial-gripping portion of vial adapter  282  by resilient feet  344  provided on the proximal end of inner valve sleeve  286 . In this initial position, an annular protruded area  346  on the inner diameter of inner valve sleeve  286  seals channels  330  formed in plug  288 , thereby preventing liquid from passing out of central channel  326 .  
         [0085]     The insertion of nozzle/filling assembly  280  into vial adapter  282  pushes the inner valve sleeve  286  axially toward vial  290 , compressing feet  344  and moving the sleeve so that the annular protruded area  346  does not seal channels  330  ( FIG. 19 ). Piston  296  may then be drawn back to draw a dose of injectable liquid into fluid chamber  298  of nozzle  292 . To create suction, the outer diameter of inner valve sleeve  286  may also be provided with an annular protruded area  348  to seal against the inner diameter of filling adapter  294 .  
         [0086]     After piston  296  has been withdrawn to draw in a dose of injectable fluid, filling adapter  294  may be broken away from nozzle  292 . Typically, nozzle/filling assembly  280  is manufactured so that there is a frangible or breakable connection  360  between filling adapter  294  and nozzle  292  at the desired breaking point. Typically, after the filling adapter is broken away, it cannot be reattached to the nozzle by the user.  
         [0087]     Referring now to  FIG. 20 , it will be appreciated that the described exemplary system prevents filling after the filling adapter has been broken away. Specifically, the figure depicts a non-compliant attempt to engage vial adapter  282  with nozzle  292  after the filling adapter has been broken away from the front of nozzle  292  (e.g., after an injection has been delivered). As shown, flexible fingers  322  of vial adapter  282  are biased inward so as to block the flanged portion  342  of nozzle  292  surrounding injection orifice  300 . Since filling adapter  294  ( FIGS. 18 and 19 ) has been broken away, no structure remains to spread the flexible adapter structure outward away from the blocking position to allow further axial movement of nozzle  292  toward vial adapter  282 .  
         [0088]     Because the flexible fingers act as a blocking mechanism or outer protective shroud that maintains nozzle  292  spaced apart from the end of inner valve sleeve  286 , the respective fluid paths of vial adapter  282  and nozzle  292  are prevented from coming into contact, thereby guarding against contamination. Also, the nozzle is prevented from pushing against the end of inner valve sleeve  286 , such that the nozzle cannot push the inner valve sleeve inward to disable the sealing of channels  330  by annular protruded area  346 . Furthermore, because filling adapter  294  has been removed, a seal cannot be established to seal an enclosed area between the fluid paths. Accordingly, it should be appreciated that the removal of filling adapter  294  guards against contamination, prevents refilling and otherwise protects against unintended use.  
         [0089]     As in the previous examples, the device depicted in  FIGS. 18-20  is configured to prevent delivery of an injection until the filling adapter is broken away and the refilling capability disabled. Specifically, the filling adapter may be disposed on the nozzle and sized so that the injection orifice is sufficiently spaced from the injection site so as to prevent an effective injection from occurring.  
       Embodiment of FIG.  21   
       [0090]      FIG. 21  depicts a further alternate embodiment of a vial adapter  380  and nozzle/filling assembly  382  Vial adapter  380  differs from the vial adapter of  FIGS. 18-20  in that it includes an alternate inner valve sleeve  384  which is biased into a sealed position by a spring  386 . In the sealed position (not shown), the inner diameter of valve sleeve  384  seals channels  330  of plug  288 . As in the example of  FIGS. 18-20 , nozzle/filling assembly  382  includes a filling adapter  388  that spreads flexible fingers  322  apart to enable the components to be positioned axially close enough to one another to defeat the sealing of channels  330  and create suction to allow fluid to be drawn into fluid chamber  298  upon retraction of piston  296 . During retraction of piston  296 , the outer diameter of valve sleeve  384  seals against the inner diameter of filling adapter  388  to create suction.  
         [0091]     Also, nozzle/filling assembly  382  differs from that of  FIGS. 18-20  in that frangible connection  390  is in a recessed location relative to injection orifice  300 . Specifically, the frangible connection is spaced axially away in a rearward direction (e.g., rearward along the injection axis) from the generally planar area at the forward end of nozzle  392  that is placed onto the injection site during delivery of an injection. This may be desirable in certain applications, to ensure that sharp edges or other irregularities resulting from breakage are prevented from coming into contact with the injection site (e.g., a patient&#39;s skin). Also, as indicated, filling adapter  388  may be fabricated as a separate piece, rather than integrally formed with nozzle  392 . In the depicted example, the separate filling adapter piece may be ultrasonically welded to nozzle  392  or secured in place with any other desired method.  
       Embodiment of FIGS.  22  and  23   
       [0092]      FIGS. 22 and 23  depict a further alternate embodiment of a vial adapter  400  and nozzle/filling assembly  402  according to the present disclosure. Similar to the example of  FIG. 21 , vial adapter includes a valve sleeve  404  which is biased (downward in  FIG. 23 ) into a sealed position by a spring  406 . A plug  408  is fitted into a cylindrical passage  410  of the vial adapter main body  412 . As in the previous exemplary embodiments, plug  408  includes channels through which fluid can flow from vial  414  out through passage  410  and out of the vial adapter (e.g., into variable volume fluid chamber  416  in which plunger  418  is disposed). However, a lower end of sleeve  404  seals these channels until the sleeve is moved out of the sealing position (e.g., moved upward against the spring tension via engagement of the vial adapter with an appropriately shaped filling adapter).  
         [0093]      FIG. 23  depicts engagement of nozzle/filling assembly  402  with vial adapter  400 . As shown, filling adapter  420  may include on its inner diameter a circumferential ledge  422  sized to bear against a lower portion of valve sleeve  404  when the components are brought together. This urges valve sleeve  404  upward against the force of spring  406 , as shown in the figure, such that fluid is now permitted to pass from passage  410 , through the channels in plug  408 , and into the injection device through injection orifice  424 .  
         [0094]     It will be appreciated that the nozzle/filling assembly  402  and vial adapter  400  provide similar advantages to the other embodiments discussed herein. In particular, filling adapter is configured so that it is frangibly connected to the nozzle, and must be broken away before an injection can be administered. As in the other embodiments, this breaking of the filling adapter prevents reuse by disabling the ability to refill the device. Specifically, once the filling adapter has been removed, the nozzle is no longer shaped to engage the opening of the vial adapter and actuate the adapter valve seal. Also, the vial adapter has an outer structure, as in previous embodiments, that acts as a protective shroud to protect the fluid pathway and reduce risk of contamination.  
       Embodiment of FIGS.  24 - 27   
       [0095]      FIGS. 24-27  depict an embodiment  510  designed to be used with a prefilled cartridge  520 . Injector  510  is virtually identical to injector  10  except that a ram extension  609  is included, and is mounted to ram  608  by a set screw  611 . When mounted in place, set screw  611  is threaded into a threaded hole  617  in ram extension  609  so that the set screw extends into a notch  614  in ram  608 . Plunger  630  is much shorter than plunger  130 , and includes an O-ring  613 . A cap  615  is also shown in  FIG. 24 , and cartridge  520  is slightly modified from cartridge  30  of injector  10 . For example, cartridge  520  is typically fabricated of Topas® cyclic olyfin copolymer (COC) from Celanese/Ticona. This material has been found to be relatively inert and therefore normally will not react with typical formulations stored in the cartridge. Other parts that are the same as those previously described and depicted in  FIGS. 1-8  and  12  have been numbered by simply adding 500 to the numbers used in injector  10  shown in  FIGS. 1-8  and  12 . The description of the structure and operation of those parts will not be repeated.  
         [0096]     The operation of injector  510  can be understood by making reference to  FIGS. 25-27 .  FIG. 25  shows injector  510  after prefilled cartridge  520  has been positioned in the injector but before firing. Ram extension  609  is shown to be mounted to ram  608  by set screw  611 . Plunger  630  is positioned in the proximal end of prefilled cartridge  520 , with cap  615  in place. In  FIG. 25  main spring  602  is shown to be compressed using a winder (not shown), just like as in injector  10  that has been previously described.  
         [0097]     In order to fire injector  510 , trigger locks  576  are depressed, disengaging trigger lock legs  580  from notch  582  in main body  512 . This permits the operator to slide trigger sleeve  514  forwardly on main body  512  as injector  510  is pressed against the patient. This releases main spring  602  as previously described, driving ram  608 , ram extension  609  and plunger  630  forwardly or in a distal direction. This causes fluid to be ejected out orifice  642  and into the patient. This just-fired position of the components is shown in  FIG. 26 .  
         [0098]     To prepare injector  510  for the next injection, the winder (not shown) compresses main spring  602  using the ratcheting operation previously described. Alternatively, the continuous rotation embodiment of the winder mechanism can be substituted. A dosage knob (not shown), like dosage knob  24  of injector  10 , is turned, and this retracts ram  608  and ram extension  609  mounted to it. This facilitates the remove and replacement of cartridge  520  through the side of injector  510  as previously described in connection with injector  10 . Because the distal end of ram extension  609  is normally perfectly positioned to abut the proximal end of plunger  630 , injector  510  is now ready for the next injection (as shown in  FIG. 25 ).  
         [0099]     While various embodiments and arrangements of a needle-free injection system and method have been shown and described above, it will be appreciated that numerous other embodiments, arrangements, and modifications are possible and are within the scope of the invention. The foregoing description should be understood to include all novel and non-obvious combinations of elements described herein, and claims may be presented in this or a later application to any novel and non-obvious combination of these elements. The foregoing embodiments are illustrative, and no single feature or element is essential to all possible combinations that may be claimed in this or a later application.