HK1110811B - Medicine injection devices and methods - Google Patents

Abstract

A reloadable medicine injector and methods are described in which a barrel with a receiving cavity is adapted to slidably receive a syringe subassembly for axial movement therein. Upon removal of a safety and release of a syringe driver, the syringe driver moves forward and injects the syringe needle. A plurality of penetration controls are shown for controlling injection needle penetration depth. The penetration controls have an abutment and various lengths to provide different needle penetration depth positions. In one form of penetration control a sleeve is used against which the syringe or related parts contact. In another form the front return spring is used as a penetration control. A cushioning ring may be used to reduce syringe breakage. A load distribution and guide ring may be used to distribute loading applied to the syringe and help guide the moving syringe.

Description

Drug injection device and method

Technical Field

The present invention relates to an injection device and a method of injecting a drug into body tissue.

Background

For many people, the self-administration of subcutaneous drug injections is a difficult task to accomplish. Some people feel a sense of incongruity in driving the needle into the meat. The result is that many people are reluctant to do so or in some cases are dizzy, and the health of these people requires regular injections or faces an emergency where self-injection is required, or requires injection of another person or animal. At least some aversion may result from seeing the needle penetrate into the muscle. And on the other hand from the action of forcing the needle into the muscle. For many people, the aversion is so strong that they simply refuse to inject themselves or to inject another person or animal.

Accordingly, there is a need for a device that can automatically inject a drug without the person performing the needle penetration and without the person actually providing the force required to drive the needle into the muscle and dispense the drug into the recipient.

Various automatic injection devices have been previously developed. The device may be used to self-administer an injection or to administer an injection for another person, merely requiring that the device be triggered. A mechanism provided in the device automatically drives the needle and dispenses the medicament. Many existing forms of auto-injectors are single use, but some also allow reloading of hypodermic cartridges (hypodermal cartridges) in which an ampoule is provided with a single fixed needle that is in open communication with the medicament in the ampoule.

There is also a need for an automatic form of syringe which can accommodate a double needle syringe in which two mutually opposed needles are slidably mounted by means of a hub on a medicament ampoule. A rearwardly facing needle is disposed adjacent the puncture seal on the ampoule such that forced movement of the syringe assembly will cause the rearward needle to puncture the ampoule seal and allow the medicament to flow to and out the forward needle. Most advantageously, the action will be performed by an auto-injector.

Another need is an auto-injector that can be adjusted for different penetration depths from body surface to subcutaneous, to muscular, and deeper penetration depths. This varies depending on the patient's condition and/or the drug being injected. This is not only a need related to auto-injectors, but also for people who are unaware of the penetration depth requirement.

There is also a need for an auto-injector that can be reloaded with a conventional ampoule to allow for multiple dose administration. The syringe allows for removal and replacement of the ampoule and reuse of the syringe mechanism. Another mode of use is to provide a first dose as a single ampoule for one injection and then reset the injector for a second injection from the same ampoule for a second or further multiple doses.

Another related need is to remove the syringe subassembly from the injection device. This may be required when the injection device malfunctions or when immediate administration of a second or subsequent dose is required.

Some or all of the above needs and others are addressed in part or in whole by the various embodiments of the invention described below.

Disclosure of Invention

The invention described is best disclosed in the detailed description section below.

Drawings

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a side cross-sectional view of a conventional prior art hypodermic syringe subassembly of the single needle type.

FIG. 2 is a side cross-sectional view of a conventional prior art double needle syringe subassembly.

FIG. 3 is a side cross-sectional view of a first embodiment device according to the present invention in a cocked state.

FIG. 4 is a side cross-sectional view similar to FIG. 3, showing the needle in an extended condition.

FIG. 5 is a side sectional view similar to FIG. 3 with the dual needle syringe assembly in a cocked state.

FIG. 6 is a side sectional view similar to FIG. 5 showing the dual needle syringe assembly in an extended condition.

Fig. 7 is a detailed enlarged cross-sectional view of a dose adjustment and stop arrangement by which multiple doses can be injected from the same syringe subassembly.

Fig. 8 is a view similar to fig. 7, showing the stop collar removed and the retaining element of fig. 7 in a position for a second dose.

FIG. 9 is an enlarged detail cross-sectional view of an embodiment of a cartridge penetration controller used in conjunction with a single needle subassembly with the needle in a retracted position.

Fig. 10 is a view similar to fig. 9 showing the syringe subassembly engaged with the cartridge penetration controller and the needle extended to a desired penetration depth.

FIG. 11 is an enlarged detail cross-sectional view of an embodiment of a compression spring penetration controller used in conjunction with a dual needle subassembly with the needle in a retracted position.

Fig. 12 is a view similar to fig. 11, but showing the ampoule seal broken, the compression spring penetration control compressed and advancing the needle in the extended position.

FIG. 13 is a cross-sectional view showing the end cap and penetration controller wherein various lengths of control sleeves can be selected and mounted for variably controlling needle penetration to various selected penetration depths.

FIG. 14 is a cross-sectional view showing the end cap and a compression spring penetration controller installed. Control springs of various lengths and other parameters may be used to control needle penetration to various selected depths.

Fig. 15A through 15F are different compression spring penetration controls showing various lengths and spiral advancement rates that affect needle penetration depth.

FIG. 16 is a top view of a preferred stop collar.

FIG. 17 is a side view of the stop collar of FIG. 16.

Figure 18 is an end view of a preferred sheath remover.

Fig. 19 is a side view of the sheath remover of fig. 18.

Fig. 20 is a side view of an actuator rod structure having four legs.

Fig. 21 is an end view of the actuator stem of fig. 20.

FIG. 22 is an end view of a preferred lancing controller cartridge.

FIG. 23 is a side cross-sectional view of the lancing controller cartridge of FIG. 22 taken along section line 23-23 of FIG. 22.

FIG. 24 is an enlarged partial side sectional view of the nozzle end of the preferred injector configuration with the elastomeric pad and load distribution and guide ring positioned between the syringe shoulders. The injector is in a cocked state and the syringe is retracted.

FIG. 25 is a view similar to FIG. 24, with the injector shown with the syringe assembly in an extended position.

FIG. 26 is an enlarged partial side sectional view of another preferred form of the invention in a cocked state with the needle retracted.

FIG. 27 is a partial view similar to FIG. 26 showing the injector having the syringe assembly in an extended position.

Fig. 28 is a sectional view showing the storage case of the preferred automatic injector according to the present invention.

Fig. 29 is a side view of the bottom of the tank shown in fig. 28.

Fig. 30 is a detailed enlarged sectional view as shown in circle 30 in fig. 29.

Fig. 31 is a side view of the upper portion of the tank shown in fig. 28.

FIG. 32 is a top end view of the upper tank portion of the tank shown in FIG. 31.

FIG. 33 is a bottom end view of the upper tank portion of the tank shown in FIG. 31.

Fig. 34 is a detailed view showing a mounting extension forming portion of the upper tank portion of fig. 31.

FIG. 35 is a side view of a mounting extension at circle 35 shown in FIG. 31 for mounting a clip (clip) to the upper box portion of FIG. 31.

Fig. 36 is an enlarged cross-sectional view at circle 36 of fig. 31.

Detailed Description

Introductory comments

The reader of this document should understand that the embodiments described herein may rely on technical terms used in any part of this document, as well as terms readily apparent from the figures and common language for the elements or operations described. The precondition for this document is: for similar structures, functions, features and aspects of the invention, one or more terms used in one embodiment may be generally applied to other embodiments. The words used in the appended claims are also used to describe the invention. Technical terms used in one, some, or all embodiments may be used to describe or define the technical term and the exclusive rights associated therewith.

Syringe subassembly

Figures 1 and 2 show syringe subassemblies 10 and 11 that can be used with the present invention. The syringe assemblies or subassemblies 10 and 11 shown are of known construction and are commercially available. A typical commercially available subassembly is manufactured, sold or distributed by Hospira, Inc. under the CARPUJECTS tradename^TM. Other subassemblies are also suitable, but some modifications may be required, depending on the particular configuration.

Both subassembly configurations include an ampoule 12, which may be a small glass or plastic bottle, for containing a measured volume of a fluid drug, medicament, or other injectable substance. The amount of the substance may be predetermined based on the nature of the substance and the intended use. The ampoule 12 may be pre-filled with the substance and provided by the manufacturer or distributor of the substance.

In both versions, the ampoule or bottle 12 includes a rear end 13 that can be opened to slidably receive a plunger 14. The plunger and plunger stopper may be moved axially in the ampoule cavity 15 by applying an axial force to the plunger shaft or rod. When the plunger assembly is compressed toward the forward or needle end, the plunger 14 may thereby force the substance out through the hollow needle assembly 16 at the forward end of the ampoule.

Subassemblies 10 and 11 differ in the construction of their needle assembly 16. The subassembly 10 (fig. 1) is of the fixed needle type, in which a fixed hollow needle 17 is mounted to an associated ampoule 12 by a fixed hub 21. The needle 17 is in open communication with the substance in the ampoule 12 and is operable to eject the substance in response to a forced compressive movement of the plunger 14. For hygienic and safety reasons, a sheath 19 may be included to releasably cover the fixed needle 17 and must be removed or pierced by the needle before an injection can be made.

The needle assembly 16 (fig. 2) for the syringe subassembly 11 differs in construction from the fixed needle assembly 10 described above. The syringe subassembly 11 utilizes a dual needle assembly 20 in which a dual needle hub 90 or 21 is fitted with a seal piercing needle 22 projecting rearwardly toward a pierceable seal 23 on an associated ampoule 12. The muscle puncture needle 24 protrudes forward. In fact, both needles 22 and 24 may be integrally formed. In such a unitary construction, the two needles may be formed from the same needle cannula which is sharp at both ends and immovably fixed to needle assembly hub 90.

Hub 90 mounts two needles 22 and 24 and has a cup-shaped receptacle for receiving the sealed end of ampoule 12. It also preferably has features or configuration to mount a needle in axial sliding relationship with the seal holder 25 of the attached ampoule 12. Forced sliding movement of ampoule 12 relative to hub 90 will thereby cause seal piercing needle 22 to engage pierceable seal 23 and then pierce pierceable seal 23. Once seal 23 is pierced, the contents of ampoule 12 may be forced through the single needle or needles 22 and 24 when an injection is administered.

The dual needle subassembly 11 may also use a protective needle shield 19. The sheath may vary or be substantially the same, or even different from the sheath of the single needle subassembly 10. For either form of subassembly, the sheath 19 may be provided as a rigid cap or a flexible cap that is pierced by the adjacent needle upon application of sufficient axial force. This is disclosed in my earlier granted US patents US5,540,664 and US5,695,472; the disclosures of which are hereby incorporated by reference into this application. Also included in this application by reference are my earlier US patents US5,358,489 and US5,665,071.

Overview of injection device

There is shown in the drawings a reloadable hypodermic injection device according to the present invention, here designated by reference numeral 30. The injection device 30 (fig. 3 to 6) comprises a barrel 31 having a nozzle end 32 with a needle-receiving bore or passage 34. A syringe subassembly receiving chamber 35 is positioned along and within barrel 31, preferably near nozzle end 32 and accessible from nozzle 32. Chamber 35 is adapted to releasably and slidably receive syringe subassembly 10 or 11 for movement toward or away from nozzle end 32. Needle assembly 16 is aligned to project through needle receiving aperture 34 or through a protective septum (not shown) positioned across aperture 34 and similar to aperture 34.

Syringe driver 36 has an actuator or driver contact 37 that is movable toward nozzle end 32 extending into syringe subassembly receiving cavity 35. A penetration controller 38 or other penetration control is also advantageously provided. The penetration controller may include a penetration control abutment surface 39 that may engage the ampoule assembly, such as on a shoulder or other suitable feature. The penetration control has a suitable length and configuration relative to nozzle end 32 to provide a desired needle penetration depth or forward needle stop position.

Barrel body

As illustrated by way of example in the drawings, barrel 31 is elongate tubular defining a subassembly receiving cavity 35 between rearward end 41 and nozzle end 32. The tub may be formed of plastic or other suitable medically acceptable material having suitable strength.

The driver guide or driver spring guide 33 may be integrally formed as a sleeve in the barrel 31 or assembled as a sleeve to hold the driver spring or other driver force generator in a desired position, such as coaxially positioned therein. As shown, guide 33 serves to guide the extension and retraction of syringe driver spring 36. The guide 33 also advantageously acts as a locator as shown to accurately axially locate the syringe assemblies 10, 11 in the barrel 31.

In the illustrated form, the barrel rear end 41 is adapted to mount an annular end plate or firing bushing 43 (the details of which will be described further below) for use in conjunction with the driver 36. To facilitate assembly, the tub rear end 41 is preferably molded around an inward annular ridge 44. Alternatively, each portion may be manufactured separately and the annular ridge 44 snap fit with the firing bushing 43.

The preferred form of the nozzle end 32 mounts a detachable nose cap 45, the nose cap 45 defining a needle aperture 34 or other passageway through which the forward needle extends when fired. The aperture or needle penetration site of the nose cap 45 is releasably connected to the barrel by internal threads 46, a ring or other protrusion. The shield 45 may thus be separated from the barrel to allow access to the barrel cavity 35 to allow insertion or removal of the needle subassembly 10 or 11.

Syringe drive

The driver 36 is used to act on the plunger or plunger stopper 14 of the needle subassembly 10 or 11, or is connected to the plunger or plunger stopper 14 of the needle subassembly 10 or 11 via the plunger rod 61. The plunger rod may be separate from or integral with the plunger stopper. The function of the driver is to force the subassembly in a forward direction to effect needle penetration and act on the plunger to inject the ampoule contents. The force is automatically applied by a spring or other suitable actuator force activated by a user-activated triggering operation.

The driver 36, as an example herein, includes a driver rod 37 or shaft 37 (fig. 3, 4) shown in the barrel 31 in a rearward cocked position by a driver release mechanism 53, which may be similar or identical to the mechanisms shown in U.S. patents US5,540,664 and US5,358,489, the contents of which are incorporated herein by reference.

While incorporating the above materials, a preferred driver is further presented herein that includes a drive spring 50 that is compressed when ready or cocked. The drive spring 50 is preferably guided by and contained in the tub by a spring guide, which advantageously takes the form of a guide sleeve 51. As shown, the guide sleeve is tubular and the guide spring is extendable in the tubular guide sleeve 51, and part of the spring 50 is slidable in the guide sleeve 51. Other configurations are also suitable.

The drive spring is selected to provide sufficient reserve energy when compressed to advance the needle subassembly against downstream resistance and perform needle penetration and injection functions. It is used to replace the plunger 14 and thereby expel the medicament contained in the ampoule 12 through the injection needle 17.

The drive spring 50 acts on the firing bushing 43 at one end and is restrained by the firing bushing 43. The opposite end of the drive spring 50 supports the driver rod 37 which is engaged with the plunger rod 61. The actuator rod or shaft 37 by way of example is provided with a spring engaging shoulder 52 (see fig. 3) against which the forward end 51 of the actuator spring engages.

As shown, the driver release 53 includes one or more barbs 54 that fit into a central aperture of the firing bushing 43. Barbs are preferably formed on the flexible ends of the legs of the actuator stem or shaft 37.

A safety, advantageously in the form of a safety cap 55, has a forwardly projecting pin 56 that is received between the legs of the driver rod or shaft to retain the barbs 54 in engagement with the firing bushing 43 to prevent forward movement of the driver rod 37 until the safety is removed. The safety device or safety cap 55 can be pulled back to slide the tapered safety pin 56 from between the legs of the driver rod. This releases the barbs that are forced radially inward together. As shown, the barbed legs of the driver rod 37 are moved inwardly by the rear or distal end of the firing sleeve 57 (as will be described in further detail below). The firing sleeve 57 acts as a trigger.

Fig. 20 and 21 show a preferred actuator shaft or rod having four legs, but other numbers are possible. The actuator shaft or rod is preferably made using two parts 37a and 37b that fit together. The parts may alternatively be made of metal and moulded or formed as one piece.

When influenced by the outer firing sleeve 57, the radially inward movement of the barbed legs of the releaser 53 causes the barbs 54 to move into the released position. In the illustrated construction, the firing sleeve 57 extends over and along the exterior of the barrel. The exposed length of the firing sleeve allows a user to hold the injector by grasping the firing sleeve while performing an injection.

The forward end of the firing or trigger sleeve may include a groove 58 formed along the forward end of the barrel that gradually sinks along a stop 59 (see fig. 4-6, 9 and 10). The retainer advantageously forms a peninsular configuration that provides flexibility to the retainer 59 for assembly or possible disassembly. The interaction between the stop 59 and the slot 58 prevents the firing sleeve from being inadvertently removed from the barrel. This interaction also limits the extent of relative axial movement, while also allowing assembly or disassembly of the parts by depressing the stop 59.

The firing sleeve 57 includes a trigger head having a preferably centrally located opening 60 (fig. 3-6). The trigger head of the sleeve 57 is advantageously inclined along the contact area with the barb 54. The openings 60 receive and project inwardly the barbs 54 on the legs of the actuator stem 37. This forces the barbed ends together once the safety cap is removed and the firing sleeve is moved forward relative to the barrel. This action triggers the actuator release 53 to release the drive spring 50. The drive spring 50 thus extends longitudinally, driving the driver rod 37 into the plunger shaft and urging the syringe subassembly forward for injection.

Fig. 3 to 6, 7 and 8 show that the driver rod 37 is configured to push against an adjustable plunger rod 61 connected to the plunger 14. The plunger shaft assembly may be part of the cartridge subassembly 10 or 11. Alternatively, the plunger shaft or rod 61 is produced as an integral part of the driver or as a separate component or part. The plunger shaft may also be made in a non-adjustable configuration, such as a solid configuration, or as a non-adjustable component.

In the embodiment shown, the plunger rod 61 is advantageously constituted by two axially adjustable elements comprising an actuator or driver engaging portion 62 and a plunger engaging portion 63. As shown, portions 62 and 63 are threadably engaged to allow for adjustment of the overall length of rod 61. This is used to help regulate the dose or volume of material dispensed during a single operation of the injection device.

The illustrated plunger rod 61 is advantageously two axially adjustable portions 62, 63 allowing for longitudinal rod length adjustment and for threaded or other connection with the plunger 14. As shown, portion 62 has a head and threads that are received in portion 63. The portion 63 of the plunger rod 61 is connected, such as by a threaded connection or with the plunger 14. Relative rotation of the two parts 62, 63 is effective to vary the length of the plunger rod 61, thereby allowing precise dose adjustment, even changes in the length of the barrel, until adjusted to the same or other desired length.

It is also possible that a different conventional form of plunger rod (not shown) may be provided as part of syringe subassembly 10 or 11. Adjustable lever 61 may not be needed or used in the alternative configuration. In this configuration, dose adjustment may be sufficiently accurate by using a properly selected stop collar 64 (discussed further below). In either configuration, the plunger rod 61 or an alternative integral plunger rod (not shown) may be provided with or as part of the plunger assembly. With an adjustable plunger rod such as formed by portions 62 and 63, dose control is more accurate because each ampoule may change length and the adjustability may be adjusted to accommodate the change. This is required when the medicament is dispensed in very precise doses. Other drugs may be less sensitive to dose response and therefore adjustment of the cost of the adjustable plunger and adjustments in production may not be necessary or reasonable.

Dose adjustment

The device can be used for single or multiple injections. To accomplish this, one or more stops in the form of dose stop collars 64 (fig. 7) are releasably mounted to the driver 36, or in the example depicted, to the plunger rod 61. In the illustrated embodiment, one such collar 64 is shown connected to the rod 61 at the rear of the ampoule 12 and at the front end of the head portion 62 of the plunger rod. The collar 64 and possibly a plurality of said collars are advantageously positioned in the forward path of the head end of the plunger rod 61. The one or more collars 64 stop forward movement of the plunger rod 61 when a selected first dose has been expelled from the syringe subassembly 10 or 11.

If the second dose remains in the ampoule after the first injection, the syringe subassembly 10 or 11 may be removed from the barrel to enable access to the collar 64, and the collar 64 may then be removed from the plunger rod 61 to allow further movement of the plunger to deliver a further dose.

After the syringe and collar are removed, the syringe driver 36 may be re-cocked, but the cocking process requires that the barrel 31 be held in response to the force required to re-compress the drive spring 50. This can be difficult in the configurations shown and described herein because the firing sleeve or trigger handle 57 extends over a substantial length of the barrel 31. In other embodiments or considerations, the syringe may be re-cocked by holding the barrel and inserting a screw drive or similar tool and compressing the drive rod 37 and associated drive spring 50. If recocked, the syringe subassembly can be reinserted into the barrel to automatically inject a second or further dose that can be used when the plunger is allowed to travel further forward in response to a subsequent trigger.

The length dimension of the collar 64 or collars may be selected according to the desired dose to be administered. Although not shown, multiple collars may be stacked along the plunger rod, with each collar representing a dose of medicament or other substance from the ampoule. The separate injections may be performed after successive removal of the stop collar. Alternatively, in the case where a single dose is required, a single or even no stop collar may be selected depending on the single dose required.

Stop collar 64 can be made with different arcuate dimensions. In some cases the collar extends completely around the plunger shaft. The presently preferred stop collar has an arcuate dimension of about 180 to 200 radians. Fig. 16 and 17 show a presently preferred design having open sides and an arcuate dimension 110 of about 185 to 190 radians. The opposite open side 111 is advantageously provided with an end face 112 which is inclined so as to converge inwardly. These features provide for easier mounting of the actuator during production and easier removal by the user after the first or other previous dose has been injected.

Other features that facilitate removal of stop collar 64 shown in fig. 16 and 17 are the configuration of ribs, grooves, striations or other friction features 120. These friction features improve the manual grip of the collar to remove it from the outside of the plunger shaft 61. This configuration allows the user to remove the collar using the thumb and forefinger of a single hand. It improves the removal work so that two hands are not required, unlike in the case of earlier designs. This improvement greatly reduces the chance that the action of removing the stop collar will result in inadvertent compression or upward movement of the plunger 14 which compromises the accuracy of the second dose.

The outer portion of stop collar 64 is also advantageously provided with circumferential portions 121 and flat portions 122 between friction features 120. The flat portion 122 facilitates mounting of the stop collar 64 on the plunger rod 61.

The inner surface 124 is preferably semi-cylindrical and sized to mate with the plunger rod 61. The particular size may vary based on the size of the ampoule 12 and the size and type of plunger rod 14 used.

Hood or nozzle end piece

Fig. 6 shows the nose cap 45, which may be advantageously detached from the barrel to allow insertion and removal of the syringe subassembly. The hood 45 may be generally cup-shaped to be received over the forward end of the barrel 31. In the illustrated embodiment, the nose cap fits over the outward surface of the barrel. The hood is attached to the surface using threads or other suitable connectors. Depending on the particular configuration used, the hood may alternatively fit within the barrel.

For precision in needle penetration depth control, the nose cap 45 is preferably axially fixed against a positive stop, such as a shoulder 47 formed along the barrel 31. A shoulder 47 may be provided along the barrel 31 to precisely locate the mounted nose cap 45 in a repeatable manner. This is preferred in order to provide axial accuracy of the relative position of the nose cap 45 on the barrel. This is desirable because the nose cap can be repeatedly removed and reinstalled, enabling removal and replacement of the ampoule and needle subassembly.

It is advantageous to use threads 46 to precisely locate the nose cap 45. Threads 46 are provided along the nose cap 45 and barrel 31 to facilitate secure engagement between the abutment shoulder 47 and the nose cap 45. However, unlike the threads 46 shown, a secure arrangement between the nose cap 45 and barrel 31 may be used. For example, a bayonet, barb and snap or other releasable connection arrangement may also be used to releasably interlock the nose cap and adjacent forward portion of barrel 31 to provide repeatable precision positioning.

The forward end of the nose cap 45 defines the needle aperture or passage 34 as shown. The needle aperture or passage 34 is advantageously arranged to receive the needle shield 19 therein. As shown in fig. 9 and 10, the needle safety shield may protrude through the aperture 34. The sheath 19 may be provided with a blunt front end which may extend to the front end of the nozzle end 34. The protrusion of the sheath 19 facilitates rapid removal of the sheath 19 prior to use.

The outside of the nose cap 45 may advantageously be provided with ribs, grooves, striations or other frictional surfaces to facilitate installation and removal of the nose cap from the barrel. The configuration shown uses a threaded connection between the nose cap and barrel. An external friction surface that allows torque to be applied is therefore preferred in this configuration. Preferably, the rubbing surface has minute linear longitudinal stripes (not shown).

Sheath remover

Removal of the sheath 19 from the syringe subassembly 10 or 11 may be achieved or facilitated by the provision of a sheath remover 80 releasably mounted at the nozzle end 32. Fig. 18 shows a typical sheath remover 80 from the front. Fig. 19 shows a side view of the sheath remover. The illustrated construction includes a sheath 19 holder 81. The holder has a central bore 85 disposed in generally axial relation to the needle-receiving bore 34 of the hood. The central bore 85 receives the sheath 19 therein.

The holder 81 also preferably includes radially inwardly projecting fingers 82 that flexibly hold the sheath 19 adjacent the tip of the sheath remover 80 behind a lip 89 (see fig. 3). The inwardly projecting fingers 82 provide sufficient flexibility to allow the sheath remover to be pushed over and fit over the enlarged end of the sheath 19 adjacent the lip 89.

The collar portion 84 extends rearwardly of the end face 87 and is received over the nose cap 45. The collar portion 84 may be provided with axial ribs 83 to improve the manual grip of the sheath remover 80 in order to facilitate pulling the sheath 19 and sheath remover from the syringe.

The fingers 82 flex back during sheath 19 removal and catch on the lip 89 and securely grip the sheath 19 when the remover 80 is pulled forward. In doing so, the fingers will catch behind the lip and further adhere and pull the sheath 19 from the needle assembly hub 90 (fig. 3) to expose the outwardly facing needle 17. The sheath 19 and sheath remover 80 may be later reinstalled in the event that it is needed to re-cover the needle for safety purposes.

Puncture controller

When triggered, syringe driver 36 urges syringe subassembly 10 or 11 forward in barrel cavity 35. This drives the needle 17 forward through the aperture 34 to pierce the patient's muscles. The depth of penetration according to the present invention is advantageously determined using penetration controller 38 (fig. 9-15) and other alternatives described herein. The penetration controller stops penetration at the desired repeatable penetration depth of the needle 17. This is different from dose control because the penetration depth is measured from the nose cap which actually contacts the muscle during automatic injection.

A preferred form penetration control 38 is positioned along the barrel 31 with an abutment surface 39 spaced from the nozzle end 32 at a selected and desired needle penetration depth stop position. The penetration control is engaged by the syringe assembly to stop forward movement of the muscle penetration needle 17 at the selected penetration depth. This is done to eliminate the need for the user to determine the penetration depth. By providing a penetration control 38, the device can be selected or adjusted so that the needle can penetrate only to the desired depth as an automatic function of the device. Adjustment is preferably provided using a lancing sleeve, spring, or other lancing controller 38 element.

First exemplary puncture controller 38

In a preferred form, penetration control is provided by penetration controller 38. The penetration controller 38 may be configured in a more specialized form having a tubular sleeve 70 portion retained within the nose cap 45. Fig. 22 and 23 show the penetration controller 38 in detail. The penetration controller 38 includes a control sleeve 70 having a flange 170 connected thereto. Advantageously, the sleeve 70 and flange 170 are shaped to frictionally engage in the nose cap 45. This is desirable so that removal of the nose cap may also result in removal of the penetration control 38. This is facilitated by the flange blades 170a tending to tilt in the cavity of the nose cap 45 (FIG. 22). This mounting arrangement also helps to provide repeatable and accurate axial positioning of the abutment surface 39 in the barrel 31 and relative to the outer front face of the nose cap or other muscular interface of the syringe. The thickness of the flange sleeve 70 and flange 170 define the length of the controller. The end of the barrel opposite the flange provides a syringe abutment surface 39 at a selected distance from the nozzle end. In this example, surface 39 is at the rear end of sleeve 70 and faces the needle subassembly in cavity 35.

The overall length of the controller 38 is generally defined by the length of the sleeve 70. The length may be selected from a group having varying axial dimensions to affect different needle penetration depths. One sleeve can therefore be used for subcutaneous injections, while the other can be selected when deeper muscle penetration is required. The choice of different axial length sleeves may be used depending on the drug to be provided into the syringe or the particular needle penetration depth required.

The sleeve 70 also serves to house a forward or return spring 71, preferably of the helical compression type, which may be disposed in the barrel between the nose cap 45 and the needle hub. A forward or return spring 71 is provided to yieldably resist forward movement of the needle subassembly, holding the subassembly in the retracted position until the syringe driver 36 is triggered. The spring 71 also helps reduce contact of the syringe assembly with the penetration control, thereby reducing or eliminating breakage of the hub or penetration control.

The penetration control unit 38 may be used to connect the return spring 71 in position in the barrel using the flange 170. This also helps retain the spring for removal with the nose cap 45 (fig. 13). To this end, the spring diameter may be enlarged at its forward end 72 to provide a friction fit between the spring 71, the sleeve 70 and the nose cap 45, while allowing the remainder of the spring to move freely within the confines of the sleeve portion 70.

An important function of the return spring is to maintain the needle in a concealed, retracted position after the sheath is pulled off. This prevents the user from seeing the needle and from being frightened by the needle. The return spring acts quickly to remove the shield to return the barrel upward into the barrel so that the user does not see the remainder of the needle positioned in the concealed position.

By providing the above-described return spring 71 and sleeve 70 arrangement, the fully axially compressed spring length will be less than the length of the sleeve. The penetration depth is thus determined by the selected length of the sleeve 70 and flange 170. With proper design, the yieldable resistance provided by spring 71 will remain within appropriate limits regardless of the length of the sleeve selected to adjust the penetration depth.

The above arrangement, in which the return spring 71, the selection sleeve 70 and the flange 170 and the nose cap 45 are interconnected, advantageously simplifies connection to and removal from the barrel 31. A user wishing to access the needle subassembly for replacement or a second injection need only unscrew the nose cap 45 from the barrel end. The return spring 71 and sleeve 70 will move with the nose cap to allow free access to the cavity 35. The vanes 170a may interact with the internal threads of the nose cap when disconnected from the barrel to help prevent free fly motion of the nose cap, sleeve and forward spring.

Second exemplary puncture controller

Another form of penetration controller may be provided in the form and configuration of: using a special selected spring of fully compressed length dimension. Fig. 15A to 15C show as an example several springs 75, 76, 77 which may have different fully compressed lengths but the same length when mounted in the device 30. In each spring, one end of the spring will act as an abutment against which the needle hub engages or against which other components engage (as will be explained further below). The needle hub will stop when the spring is fully compressed and the desired penetration depth is reached.

By using a spring 75 selected for the desired compression length, the spring itself becomes the penetration controller when fully compressed between the needle hub and the nose cap 45. The spring can thus have a dual function. Providing a yieldable resistance to slow forward movement of an adjacent needle subassembly; and stopping the forward movement once the needle reaches the selected depth and the spring becomes fully compressed.

Selected springs 75 to 77 may be friction fit in the nose cap 45 to hold the springs and nose cap together. This simplifies access to the chamber 35 and the needle assembly therein. It also mitigates rapid movement temporary discharge of the nose cap and spring when disconnected. Thus, the cover 45 and spring can be assembled so that both can be removed from the bucket as a unit at the same time.

Changing one spring for another to accommodate different penetration depths is a simple matter of removing the nose cap from the barrel and changing the spring. Alternatively, an assembly comprising a nose cap and a different spring may be used to vary the penetration depth.

Fig. 15D, 15E and 15F illustrate other novel concepts of using a forward spring for puncturing the controller 38 and absorbing energy from the moving drive and syringe assembly. Fig. 15D shows the spring 78 in a free and uncompressed state. The spring 78 has three portions 78a, 78b and 78 c. Section 78a has spaced helical or spiral windings that can contract due to the force applied by the drive through the syringe assembly. Portion 78b includes one or more inelastic windings that are in close proximity or tight and generally not compressed due to the axial compressive force applied to spring 78. Portion 78c is an enlarged end coil or wire that contracts radially when installed in the nose cap receiving portion and serves to tie the spring and nose cap together.

By adjusting the relative proportions of portions 78a, 78b and 78c, the compression and energy absorption characteristics of the forward spring can be adjusted to provide different penetration controls and different deceleration characteristics. More inelastic coils reduce energy absorption when the forward spring 78 is compressed because there are fewer active coils to absorb energy. The inelastic coil can therefore be used to hold sufficient energy to inject and dispense the medicament.

Fig. 15E shows the spring 78 in a fully compressed but axially aligned and stacked state. This occurs when the spring has stronger and/or larger spring wires. A spring made of a stronger wire will thus reach a fully compressed state and then stop fairly abruptly at the exemplary puncture depth for that spring's design.

Fig. 15F shows a spring 79 similar to spring 78, with similar parts. However, spring 79 exhibits a different type of performance when fully compressed. The spring wire is made thinner but less strong. This causes the spring to compress and then twist into a distorted, collapsed state. This state provides a two-stage compression action. In a first stage or period, the springs are compressed into a typical or near typical stacked arrangement. In a second phase or period, the spring is twisted and the various windings are forced to change radially, thereby twisting and collapsing and some windings move inside or overlap other windings. This configuration effectively provides shock absorption and energy absorption capabilities, reduces shock after the springs have been fully compressed and allows energy absorption after fully compressed into a stacked array and helps eliminate leakage of the syringe hub and other parts of the injector. It also provides buffering when the syringe and drive are slowed to a stopped state.

For example, a coiled or coiled piano wire having a wire diameter dimension of about 0.015 inches tends to collapse and twist, as shown in fig. 15F. In contrast, a spring wound from piano wire having a diameter size of 0.018 inches is easily retained as a stacked coil array, as shown in fig. 15E.

These are the presently preferred wire sizes for injection devices that use only a spring as the penetration controller. While the configurations are not accurate in demonstrating consistent penetration depths, they are consistent enough for many injections of drugs. They are also more economical to produce and eliminate a puncture control member having a tubular sleeve 70 and a flange 170 or other similar relatively inelastic puncture control element. They are also relatively inexpensive to produce and assemble.

The use of thinner spring wires has another beneficial effect. The spring tends to twist more easily and further reduces the risk of rapid movement of the nose cap and spring assembly when removed, such as when preparing for injection of a second or subsequent dose.

-syringe assembly front spring load distribution, guidance and buffering

Figures 24 and 25 show the front of an injection device having many of the same parts as described anywhere herein. The description of the common parts is denoted by the same reference numerals and the same description, and will not be repeated below.

The difference between fig. 24 and 25 is that the load distribution ring 171 is provided to act with multiple capabilities. The first capability is to distribute the force generated between front spring 75 and the syringe, particularly at syringe assembly hub 21. The second capability is to act as a guide to help maintain the coaxial position of the syringe assembly hub in the barrel cavity. A third capability is to also distribute the force around the circular abutment 170 and equalize the force so that the force to the syringe is not concentrated.

The ring 171 is preferably made the same size as the barrel cavity portion in which the ring is guided to move during operation of the syringe. This is advantageously accomplished by forming the ring to be in the range of about-0.001 inches to about-0.004 inches compared to the inner diameter of the adjacent barrel cavity 35. Other dimensional relationships are also operable.

The ring 171 is preferably made of stainless steel or other suitable material that is strong and sufficiently hard to help evenly distribute the load applied through the ring.

Figs. 24 and 25 also show a resilient gasket in the form of a gasket or washer 172 surrounding the syringe hub 90. The gasket is preferably made of an elastomeric material such as natural rubber or Santoprene 8281-45-med having a durometer value of about 45. The diameter of the spacer ring 172 in the uncompressed state is approximately 0.030 inches smaller than the load distribution and guide 171. This allows the washer to expand radially outward as the syringe is driven against the front spring and resistance is created in relation to fluid medicament dispensed from the front needle when a load is applied thereto. An outside diameter greater than and close to the inside diameter of an adjacent bucket body may cause lateral strain that causes frictional resistance to the gasket 172 with the bucket body cavity. This in turn requires the provision of a greater driving force in order to overcome friction and create increased stress and strain on the syringe and other components of the injector.

Fig. 26 and 27 show another embodiment similar to that shown in fig. 24 and 25. The embodiment of fig. 26 and 27 is not provided with the load distributor and guide ring 171 of fig. 24 and 25. Instead, the liner 172 bears directly on the syringe hub and the front spring. While this configuration is not as preferred as in fig. 24 and 25, it is also considered to be operational. Due to the less uniform load application, a stiffer and more durable elastomeric material is required to allow for reuse of the syringe 30 so configured.

In either of the configurations shown in fig. 24-27, the pad 172 has been found to work well under the appropriate forces experienced by the syringe hub 90, and thereby reduce the risk of failure or damage to the hub 90 or other parts of the syringe assembly.

Summary of front return spring function

The front spring or return spring thus performs some important functions. It maintains the syringe assembly in the retracted position prior to use, such as during handling, transport, and carrying by the user, and other circumstances. Any of these functions may be caused by accidental or incidental forces generated on the syringe and return spring. The return spring thereby retains or helps to retain the syringe in the retracted position prior to firing, but does so in a manner that absorbs shock and minimizes the risk of the syringe ampoule breaking.

The return spring also serves to help retain the needle inside the hood or barrel to keep it in a hidden position, preventing the user from being alarmed when seeing the needle.

Another function of the return spring is to block the drive spring when an injection is triggered. The drive spring accelerates the syringe along the barrel, kinetic energy and stored spring energy preferably being dissipated to prevent or reduce the risk of breaking the syringe ampoule or other components of the front end of the injector that must gain force and dissipate energy in one way or another. The dissipation of energy is particularly enhanced when the spring is deformed, as shown in fig. 15F.

Another important aspect of the forward or return spring is that it provides, in some embodiments, proper insertion of the seal insertion needle 22 into and through the ampoule seal 23. This is accomplished by selecting a return spring that generates the required return force to seat the ampoule and insert the needle 22 at or slightly before the final penetration depth is reached. Thus, the spring may provide for a delayed injection of the medicament until the needle penetration depth is correct.

In some versions of the invention, the front or return spring itself may be used as the penetration controller. This simplifies the construction of the injector and saves costs, wherein the required consistency of the penetration controller for the medicament is within the exemplary consistency of the penetration controller spring to be used, which is desirable. Wherein these parameters are not required to conform to the more complex sleeve of the penetration controller.

Yet another advantageous function of the front return spring is to retain or help retain the spring with the hood. In the embodiment shown, this is achieved by using a spring with a coil that expands towards the front end. These larger coils serve to hold the spring with the hood when the hood is removed. This prevents or minimizes any risk of rapid disengagement of the nose cap from the spring. This nature of retaining the spring and the nose cap also simplifies handling the nose cap by holding the nose cap, spring, and any tubular penetration controller 38 together as an assembly.

It will thus be seen that the front return spring can perform a surprising number of different functions and advantages or a combination of different functions and advantages.

Consideration of the double needle syringe subassembly

The description in this regard is more general with respect to the different needle subassemblies 10, 11, as two needle forms may be used for the described structure. With respect to the dual needle subassembly, however, penetration depth controller 38 and syringe driver 36 are configured to perform the additional function of penetrating seal 23 using penetrating needle 22.

The seal piercing task is completed when the triggered syringe driver 36 forces the needle subassembly 11 forward. As the subassembly is advanced, hub 21 slides into abutment with the syringe abutment surface 39 of penetration controller 38. Although hub 21 and needle 22 will remain in an axially stationary relationship with abutment surface 39, continued application of force will cause the associated ampoule 12 to slide forwardly. The forwardly moved ampoule 12 will thereby be pierced by the rearwardly protruding needle 22.

It should be understood that the tissue penetration depth is not affected by the operation of puncturing ampoule 12. When hub 21 is moved to engage abutment surface 39, forward needle 24 will move toward the selected penetration depth. When the rearward needle 22 pierces the seal 23, the continued forward force exerted by the driver 36 on the syringe subassembly will cause the injection needle 24 to continue to be extended. Hub 21 is thus in place when full penetration of forward needle 24 occurs. Further movement of the driver 36 causes the medicament from the ampoule to be dispensed and injected.

In some cases, it may be preferable for the dual needle subassembly 11 to be in open communication with the single needle subassembly 10. This is observed as the injection needle will penetrate completely or almost completely into the muscle before the injected medicament is dispersed into the muscle. The use of a single syringe has the potential impact of placing the drug above the final needle injection depth. The double ended needle may then in practice provide a more controlled and/or reproducible dispensing of the medicament at the final needle depth. This is done in a hospital setting and manual injection consists in the doctor or nurse first setting the needle to the required depth and then depressing the plunger. It also prevents loss of medication when the injection needle passes through the intervening tissue.

The wire of some return springs has a diameter suitable for enabling the placement and desired insertion of the ampoules through the needles 22, while the injection needles reach their desired final penetration depth. This is because the spring is weak enough (less spring rate) to allow the puncture controller sleeve to perform the final placement and insertion of the needle 22 past the seal 23. In other embodiments, such as when only a spring is used as the penetration controller, the spring rate of the return spring is selected to similarly provide placement and insertion of the needle 22 through the seal 23 also at or near the desired final penetration depth. In either case, this provides proper administration to the tissue that is the tissue designated for the desired final penetration depth.

When used with a double syringe assembly such as 11, the syringe also performs another important new function. The assembly requires that the needle assembly 11 be placed manually or using a device holder prior to performing a manual injection. The act of firing the syringe carrying the double barrel causes the needle assembly to seat or mate with the sealed ampoule. The syringes used manually are therefore formed automatically. This represents the multiple functions provided by the syringes described herein. One function is to automatically administer the first dose. Another function is to house a double syringe assembly with a sealed ampoule to form a manual dose from the double syringe and sealed ampoule. A further function is to provide a reliable spare syringe for the following situations: the syringe may be misused and the second dose is the only dose and can be manually injected as a final reliable means when required in difficult situations such as battlefields or otherwise.

Storage and carrying case

Fig. 28 to 36 show a preferred outer or carrying case in which the syringes described herein may be carried in a protected manner. Fig. 28 shows a preferred carrying case 200 having a lower or bottom portion 201 and an upper or top portion 202. The upper and lower portions are connected by a detachable joint for holding the components together until such time as they are required to be used as a syringe, such as syringe 30, which can be removed from the carrying case. Before explaining the operation of the carrying case 200, a detailed explanation of the features thereof will now be given.

The carrying case 200 is designed to carry a syringe and the driver and trigger ends of the syringe are inserted into the upper case portion 202. The nozzle and needle end of the injector are inserted into the lower box section 201.

In the preferred construction shown, the bottom end receiving portion 205 receives the nozzle end of a syringe. This is preferably done so that the front wall 82 of the sheath remover rests on the support ledge 206. The protruding portion 206 is preferably padded with a ring pad 209. This configuration prevents loading of the exposed needle shield to force it to deploy during movement, handling of the carrying case in which the syringe is supported, and mishandling (such as dropping).

The length between the ledge 206 and the upper end of the case upper portion 202 is nearly equal to, but slightly less than, the length of the syringe between the safety cap 56 or other tip portion and the surface 82 of the sheath remover 80. This configuration advantageously provides a small amount of clearance to allow the syringe to be unloaded in an axial manner when stored in the carrying case.

Fig. 28 shows that the upper portion 202 of the carrying case is advantageously provided with a clip mount 206 which may be welded to the upper portion 202 or integrally formed therewith when the upper portion is formed. A clip holder is used to hold a clip 207 similar to a clip on a pen. The clip is preferably made of metal having a spring characteristic that holds the clip end 208 against the upper box portion 202. The clip may be used to help retain the carrying case in a user's pocket or other portion of a piece of luggage, briefcase, vanity or user's clothing or apparel.

Fig. 34 and 35 show the clip holder 206 in more detail. Other configurations are also possible. In any design, the holder is preferably durable, preventing the clip 207 or holder 206 from breaking away from the carrying case upper portion 202.

Fig. 28 shows that the upper and lower tank sections are preferably configured to form a knockdown joint 210. While threaded connectors are acceptable, it has been found more preferable to have connectors that can be easily and quickly removed to allow the syringe to be quickly accessed for injection of medication without delay in an emergency. In the illustrated construction, the base 201 includes an insert portion 220 (FIG. 29) sized and shaped to fit within an insert receiving portion 230 (FIG. 36) formed on the open complementary end of the upper box portion 202. The insert portion 220 is advantageously provided with one or more detent projections 221 which are received in an annular groove 231 (fig. 36) to provide a detent or mating engagement which holds the two tank sections together until desired by the user.

The connector 210 is also advantageously provided with a quick release which may be provided in the form of two protrusions 241 which are received in complementary receiving portions formed on the mating part 201. The protrusion is preferably semi-circular to fit in a semi-circular receiving portion 242 adjacent the insertion portion 220. This configuration allows the tank to be easily opened by twisting the two tank sections 201 and 202 relative to each other by only a very small angular displacement. The semicircular projections and the receiving portions thus interact to move the two tank sections away from each other and move the stopper projection 221 out of the annular groove 231. Thus, the carrying case is opened and the syringe contained therein can be easily removed simply by twisting the two case portions less than about 1/10 turns.

Fig. 36 also shows shoulder 232 recessed by an amount that extends male portion 220 into the splice-receiving portion, engaging the end face of the male portion with shoulder 232. This also facilitates the correct extension of the insert into the receiving portion with the protrusion 221 correctly fitting in the annular groove 231. Sharpness processor (sharps disposal)

The new configurations shown herein are also advantageous in that they are adapted to provide one or more sharps containers for holding the syringe assembly after an injection of medicament. In one form, the syringe assembly is removed or withdrawn from the injector through the nozzle end without the needle shield thereon. The front ends of the return spring and associated parts of the syringe assembly are also removed. The needle end of the syringe is first used and then the syringe is inserted into the barrel cavity in the opposite orientation. The nose cap 45, without the return spring and any penetration control sleeve, is then connected or attached to the barrel to protect the syringe therein for safe operation and proper disposal.

In another form, the syringe assembly is inserted into the carrying case and the two parts of the carrying case are reconnected. The carrying case acts as a portable sharps container. The invention thus provides means for carrying the cartridge and associated needle or needles for transport and handling of larger sharps containers. It can also be placed in a carrying case, providing a very good combination of damage protection and needle exposure.

Additional methods and operations

In addition to the various descriptions given anywhere herein regarding the methods and operation of the elements of the present invention, the following added explanations are provided to supplement the description.

A method aspect according to the present invention is provided for driving an injection needle 24 or 17 to a selected penetration depth. Aspects of the method will be discussed in conjunction with a description of the operation and use of the present invention.

The process initially includes placing the injector in a cocked position. This is preferably done during the manufacturing process. The injector is ready to fire with the safety cap 55 removed and the driver bar 37 pressed rearwardly. The barbs 54 on the driver shaft move and extend into the holes 60 at the firing end of the firing sleeve 57. This compresses the drive spring 50 and hooks the barbs 54 onto the ring piece 43. Once the device is ready to fire, a safety cap 55 may be installed to prevent accidental firing of the driver 36. This action positions the pin 56 between the barbed legs of the actuator stem 37. The pins 56 prevent the barbed ends from moving toward each other and releasing the driver rod or shaft. This prepares the apparatus for receiving the selected syringe assembly.

The process then involves selecting the appropriate syringe subassembly. The selection involves a barrel having the desired fluid volume, injection needle length, and durability for the intended purpose. In preparation for installation of the syringe subassembly, since the syringe is provided with a multi-dose loading, the plunger rod 61 may be connected with the syringe plunger 14, allowing the step of wherein the at least one stop collar 64 may be connected with the plunger rod 61 to be performed for dose control. If the plunger rod 61 can be adjusted in axial length, the plunger rod 61 is now adjusted to provide a desired or constant discharge volume or dose. The step of determining that a dose has been dispensed from the device is therefore complete. Once the adjusting and/or determining step has been completed, the dose setting step is completed.

A further preferred method includes inserting a selected syringe subassembly through the open forward end of barrel 31. The method further includes positioning and mounting the syringe subassembly to a desired location within the interior of barrel 31. This is accomplished by removing the nose cap 45 and sliding the selected syringe subassembly having the first open end 13 into the barrel cavity.

The above steps and procedures according to the present invention may generally be accomplished using a fixed needle or double syringe subassembly 10 or 11.

Further procedures according to the present invention may also include adjusting the penetration depth. Adjusting lancing may be accomplished by selecting a desired lancing control, spring lancing control 38, or other lancing control 38 having a length that positions abutment surface 39 at a desired position. This may include a selectable number of puncture stop positions. This can be accomplished while disengaging the nose cap 45 from the barrel 31 by either disposing a selected length of the penetration controller 38 sleeve in the nose cap or by disposing selected penetration controller springs 75-79 in the nose cap. A combination of a control spring and a fixed control element is also possible.

In the example shown in fig. 3 to 6, a sleeve-type penetration controller 38 is used which is frictionally positioned in the cap so as to abut the inner front wall of the head housing in the vicinity of the needle aperture 34. A return spring 71 is also disposed in the sleeve 70 prior to installation of the controller and spring subassembly in the interior cavity of the nose cap 45. This is preferably accomplished by the enlarged end of the spring engaging the forward flanged end 170 of the sleeve 38.

The spring, penetration controller and nose cap assembly can then be mounted to the barrel. This is advantageously accomplished in the illustrated embodiment by screwing the nose cap 45 onto the barrel 31 until the stop shoulder 47 is engaged by the rear end of the nose cap 45 to ensure proper axial spacing between the syringe abutment surface 39 and the syringe hub. The return spring may be made to abut an annular stainless steel guide and load distributor 171 (fig. 24 and 25) to help ensure precise firing and a small deceleration stop for the syringe subassembly.

Alternatively, a spring of a selected compressed length (e.g., one of springs 75-79) may be used to determine the penetration depth. In this aspect, a spring having an axially compressed length that is related to the desired needle penetration depth is selected. The selected spring is then mounted to the nose cap 45, such as by frictionally sliding the spring into position in the end cap and/or along the guides 171. The end of the spring now facing the syringe hub becomes the syringe abutment surface and the penetration depth will be measured by the fully compressed length of the spring. The spring may have various active coil counts and in some designs inelastic coils to help provide sufficient energy for the desired puncture depth for puncture. Once the selected spring is installed in the nose cap, the assembly may be threaded onto barrel 31 at a point that engages stop shoulder 47.

If not already in position on the nose cap 45, the sheath remover 80 can be slid into position on the nose cap 45 to position the sheath engaging fingers 82 over the sheath. The fingers will flex allowing the sheath remover to act by sliding over the length of the needle sheath 19 of the forward exposed nose cap 45.

Once the nose cap 45 and sheath remover 80 are in position and the safety 55 is connected, the device is loaded, cocked and in a near-ready-to-use safe state. The device can be safely carried or stored in this state until the moment of injection.

The following discussion will describe single dose and double dose uses of the illustrated and other autoinjectors according to the present invention. The described uses are all capable of using the same or similar procedures with either a single fixed needle cartridge assembly 10 or a dual needle sub-assembly 11.

Prior to injection, the user may remove the protective sheath 19 from the needle subassembly by movement, such as by sliding the sheath remover 80 forward. This performs a disengagement step to disengage the sheath remover from the nose cap. The sheath remover fingers 82 engage and capture or bond with the sheath lip 89. Further removal of the sheath remover applies an axial force to the sheath by pulling the sheath outwardly through the needle aperture 34 in the nose cap 45. The sheath remover 80 thereby performs the action of removing the sheath from the syringe assembly and other parts of the auto-injector.

The user may perform a removal step to remove the safe from the opposite end of the tub. This is advantageously done by pulling the safety 55 and attached safety pin 56 from between the barbed legs of the drive rod 37 or other drive shaft assembly. This arming step involves removing or disabling the safety device, thereby preparing the injection device for dose injection.

To perform an injection, the user presses the hood against the area of tissue to be injected. The pressing action causes the firing sleeve 57 to move forward relative to the barrel. The barbs on the drive bar or shaft assembly will move toward one another by engaging the barbs against the walls of the openings 60 and collapsing inwardly. This action releases the actuator rod, which is now permitted to move forward, such as by sliding, in response to the force applied by the actuator. The urging of the driver shaft serves to free the driver release 53 into a driving action in which the driver rod moves forward and acts by engaging the plunger rod. The driving action also urges the needle subassembly forward. This is done by puncturing adjacent tissue with a needle, and also by puncturing any second needle through the ampoule seal.

When the needle subassembly is moved forward, either return spring 71 or selected penetration control springs 75-79 are acted upon to perform the compression of the forward spring. The spring, nose cap and any penetration control act by re-constraining and stopping the forward movement of the needle hub. In arrangements where the engaging end of the return spring also constitutes the syringe abutment surface, the selected spring will fully compress at the preselected axial location, stopping needle penetration at the desired penetration depth. The same penetration depth may be achieved with an arrangement in which the return spring 71 is compressed to the point where the needle hub engages the fixed abutment surface 39 on the selected sleeve-type penetration controller 70. The penetration depth is determined by the selected axial position of the abutment surface (whether it is on the lancing controller sleeve or not) or by fully collapsing the spring of the desired fully compressed length.

Once the abutment surface or the entire spring compression point is reached, the drive spring 50 will continue to push the plunger rod forward to dispense the medicament. In the case of a single needle syringe subassembly 10, continued forward movement of the plunger will result in the injection of the medicament. The medicament is also injected after the double needle assembly 11 is provided in the barrel 31 and the ampoule is driven forward onto the seal piercing needle 22.

The medicament is injected as the spring 36 forces the plunger forward. The urging continues until such time as the plunger shaft engaging head engages any desired stop collar 64 or stack of stop collars. This marks the end of the injection and the prescribed dose is injected at the selected penetration depth. The device is now ready for either recocking and reloading another syringe subassembly, or for injecting a second or subsequent dose of medicament still in the ampoule due to the stopping action performed by the stop collar(s) 64.

As mentioned above, the penetration depth and dosage are controllable. This is advantageously done by providing a removable or adjustable stop arrangement in the barrel 31. The dose may be selectively controlled by a stop collar 64 and an adjustable length plunger rod 61. The penetration depth may be selectively controlled by selecting the axial position at which the needle hub stops in the barrel 31, such as by the penetration controller 38 or the retraction condition of the penetration controller spring, as a function of selecting or adjusting the penetration controller 38.

The novel method may further comprise performing a second injection. According to some versions of the invention, this may be accomplished using the same syringe assembly. Alternatively, this may be done using a second or subsequent syringe assembly. When using a single syringe, the user does so by removing the nose cap 45 and sliding or withdrawing the syringe assembly from the barrel cavity. Any one or more of the stop collars 64 or portions may then be removed, such as by laterally removing the one or more collars or portions from the plunger rod, thereby allowing the plunger to be pushed further forward in the ampoule to inject another dose. This is preferably used to inject the second dose in a manual mode of operation.

If the injector is used to inject a second dose, the injector is cocked by removing the syringe assembly and then holding the barrel and pressing the driver using a screw driver or other tool that extends into contact with the driver rod or shaft 37.

The safety device (such as safety cap 55) can now be repositioned on the back end of the device. This arming action causes arming pin 56 to be inserted with the actuator lever leg forming an arming opening that receives arming pin 56. The safety devices are installed by keeping them separated and putting the device into a safe state, thereby avoiding unintentional firing.

When the syringe subassembly 10 or 11 is re-received in the barrel (such as with the stop collar 64 removed), the ampoule will slide further back into the barrel until it abuts the spring guide sleeve 33 (fig. 8). When the nose cap 45 is replaced, the subassembly will be held in this position by the spring 71 (or by selected other springs 75-79). Replacement of the nose cap completes the steps required for a second or subsequent use of the device to deliver a second autoinjector dose. If the injection is performed immediately, the sheath and sheath remover need not be replaced. However, if the second injection is delayed for a period of time, the sheath 19 and sheath remover 80 may be reinstalled even if the needle is now safely carried in the nose cap. Alternatively, the sheath and sheath remover are not reinstalled to reduce the risk of injury or contamination.

The second dose administration can be accomplished automatically in the same manner as described above. In which operation the driver will depress the plunger through the axial distance previously occupied by stop collar 64.

The injection device according to the invention may also allow the injection of a second or subsequent dose to be performed manually. In an alternative mode of operation the syringe assembly is removed from the barrel in the same or similar manner as described above. If the initial dose is not sufficiently effective, the user can manually insert the forward needle into the patient's muscle and depress the plunger with the thumb. This procedure may be used when it is difficult or impossible to re-prime the driver, or to expedite a second or subsequent dose injection.

More than one stop collar may be provided and more than two injections may be made from the same barrel. It should also be noted that the injection device may be provided without a stop collar, so that the barrel may be used for only one automatic injection. Excess medicament may be provided in a syringe for manual injection. The dose can be more accurately determined by axially adjusting the head 62 of the plunger rod 61. In any case, the device may be reused. In a first mode of operation, the device may be reset by cocking and installing the same syringe previously used. In a second mode of operation, the device may be reset in the manner described above, and the second syringe subassembly may be installed and used and operated in the same manner as the first syringe.

Mode of manufacture

Many of the components of the auto-injector are preferably made by molding (such as injection molding) a suitable medical grade clear plastic into the construction shown and described herein. The metal pieces are turned or manufactured according to various known metal working processes. Preferred elements for the syringe are detailed below or have been described above.

The plunger shaft 61 is preferably made of a metallic material, such as 2024 grade aluminum, which is anodized with a transparent material in accordance with military specification MIL a 8625C colorless and transparent requirements.

The tubular penetration control sleeve is preferably made of a suitable plastic, which is molded to the desired shape and size. The preferred material is a commercially available material designated Celcon TX90 Plus. Other materials are also possible, such as Nylon 6(Capron 8253) or M270 Celcon.

The spring is preferably made of music wire, which is small in size but has high strength and excellent elastic retention. The return spring can vary, but a 0.015 inch diameter is preferred in some forms, type a 228; however, heavier wires are also preferred in various configurations. The drive spring is preferably ASTM-A313 type 17-7 PH stainless steel wire, 0.033 inch diameter.

The driver release ring 43 is preferably made of a suitable steel, such as 12L 14 grade a steel, which is preferably galvanized according to ASTM B633-85 type III SEI.

The nose cap, safety cap and sheath remover are preferably made of molded plastic such as Amoco #4039 polypropylene or Polymerland # 1120.

The needle shield is preferably made of high density polyethylene Spec. # MS-4079.

The carrying case is preferably made of an opaque or translucent colored plastic such as polypropylene, e.g., Rexene #17C9A polypropylene.

The spring clip on the carrying case is preferably made of a suitable steel (such as steel plated with chrome or other metal that does not rust easily) or a suitable stainless steel, such as 0.010 inch 301 stainless steel, with a #2 finish half hardness.

The sheath remover and safety cap are preferably made of DuPont Zytel 101L.

The firing sleeve and plunger adjustment screw are preferably made of Bayer Markrolon #2607 and 1112 polycarbonate.

The drive spring bushing is preferably made of Amoco #4039 polypropylene.

The barrel is preferably made of plexiglass DR 101 Acrylic. The spring guide for the drive spring is preferably made of Dow 478-27-W high impact polystyrene.

The stop collar and the bushing edge against which the collar abuts are preferably made of Amoco #4039 polypropylene or Polymerland # 1120.

The spring releaser is preferably made of 8 NOS high density 70/30 brass CL C2600 according to ASTM B36-91A.

Other aspects and features

The foregoing description has set forth various features and aspects of the present invention and preferred embodiments thereof. These aspects and features may be further defined in accordance with the following claims, which may stand alone or in various combinations of the recited features to thereby help define the invention.

Notes on description

The invention has been described with reference to the current embodiments shown and described in connection with various structural and methodological features. The scope of protection defined by the claims does not necessarily have to be limited to the specific features shown and described. Other forms and equivalents for carrying out the invention may also be employed without departing from the scope of the concept as properly claimed thereby.

Industrial applicability

The present invention is useful for administering and carrying medical injection devices.

Claims (5)

1. An apparatus forming a medical injector that can be used by an individual in an emergency to inject medicine through the skin of a user in an automatic mode of operation or an assisted manual mode of operation, comprising:

an elongate tubular barrel formed of a suitable medically acceptable material of suitable strength having a nozzle end with a needle-receiving bore;

a syringe subassembly receiving chamber disposed along the barrel adjacent the nozzle end and releasably and slidably receiving the syringe subassembly for movement toward and away from the nozzle end, and through which the needles of the syringe subassembly can project;

a syringe subassembly retained within the syringe subassembly receiving cavity and movable therein;

a syringe driver connected to the barrel having a driver rod capable of resisting movement of the syringe subassembly toward the nozzle end and into the syringe subassembly receiving cavity to move the syringe subassembly to dispense medication from the syringe subassembly;

a penetration controller mounted to said nozzle end of said barrel having a syringe subassembly abutment spaced from said nozzle end to achieve a desired needle penetration depth position, said penetration controller including a forward spring retaining said syringe subassembly in a retracted position within said tubular barrel with the needles of said syringe subassembly within said barrel unless said syringe driver is actuated to extend the needles of said syringe subassembly through said needle-receiving apertures therefrom;

a removable nose cap at the nozzle end of the barrel that allows a user to access the syringe subassembly for a second or subsequent dose administration when desired, wherein the removable nose cap and a penetration controller with a forward spring are connected to form a nose cap penetration control assembly that can be removed by releasing the removable nose cap;

wherein, the puncture controller comprises a puncture control sleeve, the puncture control sleeve is connected with the head cover, and the front end of the forward spring is positioned between the puncture control sleeve and the head cover.

2. An apparatus forming a medical injector that can be used by an individual in an emergency to inject medicine through the skin of a user in an automatic mode of operation or an assisted manual mode of operation, comprising:

an elongate tubular barrel formed of a suitable medically acceptable material of suitable strength having a nozzle end with a needle-receiving bore;

a syringe subassembly receiving chamber disposed along the barrel adjacent the nozzle end and releasably and slidably receiving the syringe subassembly for movement toward and away from the nozzle end, and through which the needles of the syringe subassembly can project;

a syringe subassembly retained within the syringe subassembly receiving cavity and movable therein;

a syringe driver connected to the barrel having a driver rod capable of resisting movement of the syringe subassembly toward the nozzle end and into the syringe subassembly receiving cavity to move the syringe subassembly to dispense medication from the syringe subassembly;

a penetration controller mounted to said nozzle end of said barrel having a syringe subassembly abutment spaced from said nozzle end to achieve a desired needle penetration depth position, said penetration controller including a forward spring retaining said syringe subassembly in a retracted position within said tubular barrel with the needles of said syringe subassembly within said barrel unless said syringe driver is actuated to extend the needles of said syringe subassembly through said needle-receiving apertures therefrom;

a removable nose cap at the nozzle end of the barrel that allows a user to access the syringe subassembly for a second or subsequent dose administration when desired, wherein the removable nose cap and a penetration controller with a forward spring are connected to form a nose cap penetration control assembly that can be removed by releasing the removable nose cap;

wherein the penetration controller comprises a penetration control sleeve with a flange having blades that engage the nose cap to help retain the connection of the nose cap penetration control assembly.

3. The apparatus of claim 2, wherein the flange engages internal threads of the nose cap.

4. An apparatus forming a medical injector that can be used by an individual in an emergency to inject medicine through the skin of a user in an automatic mode of operation or an assisted manual mode of operation, comprising:

an elongate tubular barrel formed of a suitable medically acceptable material of suitable strength having a nozzle end with a needle-receiving bore;

a syringe subassembly receiving chamber disposed along the barrel adjacent the nozzle end and releasably and slidably receiving the syringe subassembly for movement toward and away from the nozzle end, and through which the needles of the syringe subassembly can project;

a syringe subassembly retained within the syringe subassembly receiving cavity and movable therein;

a syringe driver connected to the barrel having a driver rod capable of resisting movement of the syringe subassembly toward the nozzle end and into the syringe subassembly receiving cavity to move the syringe subassembly to dispense medication from the syringe subassembly;

a penetration controller mounted to said nozzle end of said barrel having a syringe subassembly abutment spaced from said nozzle end to achieve a desired needle penetration depth position, said penetration controller including a forward spring retaining said syringe subassembly in a retracted position within said tubular barrel with the needles of said syringe subassembly within said barrel unless said syringe driver is actuated to extend the needles of said syringe subassembly through said needle-receiving apertures therefrom;

a removable nose cap at the nozzle end of the barrel that allows a user to access the syringe subassembly for a second or subsequent dose administration when desired, wherein the removable nose cap and a penetration controller with a forward spring are connected to form a nose cap penetration control assembly that can be removed by releasing the removable nose cap;

wherein the penetration controller comprises a penetration control sleeve having blades engaged in the removable nose cap.

5. An apparatus forming a medical injector that can be used by an individual in an emergency to inject medicine through the skin of a user in an automatic mode of operation or an assisted manual mode of operation, comprising:

an elongate tubular barrel formed of a suitable medically acceptable material of suitable strength having a nozzle end with a needle-receiving bore;

a syringe subassembly receiving chamber disposed along the barrel adjacent the nozzle end and releasably and slidably receiving the syringe subassembly for movement toward and away from the nozzle end, and through which the needles of the syringe subassembly can project;

a syringe subassembly retained within the syringe subassembly receiving cavity and movable therein;

a syringe driver connected to the barrel having a driver rod capable of resisting movement of the syringe subassembly toward the nozzle end and into the syringe subassembly receiving cavity to move the syringe subassembly to dispense medication from the syringe subassembly;

a penetration controller mounted to said nozzle end of said barrel having a syringe subassembly abutment spaced from said nozzle end to achieve a desired needle penetration depth position, said penetration controller including a forward spring retaining said syringe subassembly in a retracted position within said tubular barrel with the needles of said syringe subassembly within said barrel unless said syringe driver is actuated to extend the needles of said syringe subassembly through said needle-receiving apertures therefrom;

a removable nose cap at the nozzle end of the barrel that allows a user to access the syringe subassembly for a second or subsequent dose administration when desired, wherein the removable nose cap and a penetration controller with a forward spring are connected to form a nose cap penetration control assembly that can be removed by releasing the removable nose cap;

wherein said penetration controller comprises a penetration control sleeve with a flange and said forward spring, said spring having an enlarged end winding positioned between said flange and said removable nose cap.