This application is a continuation-in-part application of U.S. patent application serial No. 11/006,382 filed on 6.12.2004 and U.S. patent application serial No. 11/175,543 filed on 6.7.2005, the contents of which are incorporated herein by reference in their entirety.
Detailed Description
The present invention provides methods for treating allergic emergencies, such as anaphylaxis. The invention also provides a device for treating allergic emergencies, such as anaphylaxis. In addition, the present invention provides kits for treating allergic emergencies, such as anaphylaxis. As mentioned above, allergic reactions mean acute and severe allergic reactions to allergens (antigens). Treatment of anaphylaxis refers to ameliorating or alleviating the symptoms of anaphylaxis. The treatment may be, and in most cases is temporary. For example, in embodiments of the present invention, the methods, devices or kits of the present invention will provide emergency relief of symptoms of anaphylaxis, providing the patient sufficient time to seek professional medical assistance. Thus, the devices and kits of the present invention are well suited for inclusion in professional child care settings and first aid kits especially for households that are known to be at risk for one or more persons. They are also well suited for use in so-called emergency vehicles that are contained in medical emergency rooms. They may also be conveniently carried by or responsible for caring for those at risk of anaphylaxis. The method of the present invention is suitable for treating a person at risk of an allergic first aid, such as an allergic reaction, in any of the aforementioned settings.
Thus, the treatment of allergic emergencies, for which the present invention is particularly suitable, includes the treatment of anaphylaxis. In addition, treatment of allergic emergencies includes treatment of other allergic conditions that may be treated with epinephrine. For example, the symptoms of a reaction to a drug allergy closely resemble the allergic reaction and are treated in a similar manner. In cases where it is not clear whether the response is a systemic immune response (anaphylaxis) or a systemic toxic response (anaphylactoid response), the first acceptable treatment is the use of epinephrine. In this sense, treatment of an allergic emergency comprises treatment of an allergic reaction, an anaphylactoid reaction, or both.
In some embodiments, the invention provides methods of treating an allergic emergency (such as an allergic reaction) in a patient comprising administering two doses of epinephrine to the patient from the same device. The method comprises automatically injecting into the patient, when it is needed, a first dose of epinephrine consisting essentially of about 0.3mL of epinephrine solution, and then manually injecting into the patient a second dose of epinephrine consisting essentially of about 0.3mL of epinephrine solution. The concentration of epinephrine in the epinephrine solution is approximately 1mg epinephrine per ml of solution. In some embodiments, in addition to approximately 1mg epinephrine per ml of solution, the solution contains one or more non-reactive components, such as sodium bisulfite as a protective agent, a pH buffer, a component that provides isotonicity, or mixtures thereof. The first dose may be self-administered by the patient or administered by someone other than the patient, such as a caregiver or medical practitioner.
It is desirable that the patient monitors his symptoms, or that the patient is cared for the patient to monitor the symptoms. In the case where the symptoms of anaphylaxis were not adequately improved by the first auto-injection of 0.3mL of 1mg/mL epinephrine, this would require manual second dose administration. In addition, a second dose may be administered manually in the event that the patient is unable to receive professional medical assistance before the effective effect of the first auto-injected dose begins to subside. Thus, in some embodiments, the second dose is administered less than about 30 minutes after the first dose, e.g., less than about 20 minutes after the first dose. In certain embodiments, the second dose is administered less than about 10 minutes after the first dose.
The second dose may be self-administered by the patient or administered by another person other than the patient. In some embodiments, the first and second doses are both self-administered by the patient, the first and second doses are both administered by a person other than the patient, the first dose is self-administered and the second dose is administered by a person other than the patient, or the first dose is administered by a person other than the patient and the second dose is self-administered by the patient.
An automatic first injection dose of 0.3mL of a 1mg/mL epinephrine solution followed by a manual injection of the same epinephrine solution dose is particularly suitable for treating adults or children weighing more than 15 Kg. Thus, in some embodiments, the patient weighs at least about 30 Kg. In other embodiments, the patient weighs at least about 15 Kg. The 0.3mg/mL concentration is also particularly suitable for adults and children over 12 years of age.
An automatic first injection dose of 0.3mL of a 1mg/mL epinephrine solution followed by a manual injection of the same epinephrine solution dose is particularly suitable for treating adults or children over 12 years of age. Thus, in some embodiments, the patient is an adult. In other embodiments, the patient is a child over 12 years of age.
In some embodiments, the present invention provides methods for treating anaphylaxis in a patient comprising injecting the patient with two doses of epinephrine from the same device. The method comprises automatically injecting into the patient, when it is needed, a first dose of epinephrine consisting essentially of about 0.15mL of epinephrine solution, and then manually injecting into the patient a second dose of epinephrine consisting essentially of about 0.15mL of epinephrine solution. The concentration of epinephrine in the epinephrine solution is approximately 1mg epinephrine per ml of solution. In some embodiments, the solution contains one or more non-reactive components, such as sodium bisulfite as a protective agent, a pH buffer, a component that provides isotonicity, or a mixture thereof, in addition to 1mg epinephrine per ml of solution.
It is desirable that the patient monitors his symptoms, or that the person caring for the patient monitors the patient's symptoms. In the case where the symptoms of anaphylaxis were not adequately improved by the first auto-injection of 0.15mL of 1mg/mL epinephrine, this would require a second manual dose administration. Additionally, in the event that the patient is unable to receive professional medical assistance before the effective effect of the first auto-injected dose begins to subside, a second dose is manually administered. Thus, in some embodiments, the second dose is administered less than about 30 minutes after the first dose, e.g., less than about 20 minutes after the first dose. In certain embodiments, the second dose is administered less than about 10 minutes after the first dose.
The second dose may be self-administered by the patient or administered by a person other than the patient. In some embodiments, the first and second doses are both self-administered by the patient, the first and second doses are both administered by a person other than the patient, the first dose is self-administered and the second dose is administered by a person other than the patient, or the first dose is administered by a person other than the patient and the second dose is self-administered by the patient.
A smaller dose of epinephrine solution (0.15mg/mL) is particularly suitable for treating smaller patients for whom injection of a larger volume of 0.3mg/mL is uncomfortable, painful or dangerous. Thus, in some embodiments, wherein the dose is 0.15mg/mL, the patient's body weight is 30 Kg. In a particular embodiment, the patient weighs 15 Kg.
A lower dose of epinephrine solution (0.15mg/mL) is particularly suitable for treating patients of a smaller age, particularly children, for whom injection of a larger volume of 0.3mg/mL is uncomfortable, painful or dangerous. Thus, in some embodiments, wherein the dose is 0.15mg/mL of 1: 1000 diluted epinephrine, the patient is a child. In a particular embodiment, the child is less than about 12 years old.
In some embodiments, the present invention provides a delivery device for treating anaphylaxis. The drug delivery device contains enough epinephrine solution for injection of at least two doses of epinephrine solution of 0.15 or 0.3mL each. The epinephrine solution has a concentration of about 1 milligram of epinephrine per milliliter of solution. In some embodiments, the epinephrine solution contains, in addition to 1mg per ml of solution, at least one pharmaceutically non-reactive component, such as sodium bisulfite as a protective agent, a pH buffer, an agent for adjusting the degree of penetration (such as to establish or maintain isotonicity with the tissue into which the solution is injected), or a mixture of two or more of the foregoing. Thus, herein, unless specifically defined, the term "epinephrine solution" refers to a solution of 1mg epinephrine per ml of aqueous solution, optionally including one or more additional ingredients other than epinephrine and water, such as protectants, buffers, agents for adjusting osmolarity.
Embodiments of the device are provided in U.S. patent No. 11/006,382, filed on US5,695,472 and 2004, on 6.12.2004, both of which are incorporated herein by reference in their entirety.
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 tradenameTM. 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 the aforementioned epinephrine solution (1: 1000). The amount of epinephrine solution will be sufficient to deliver the entire amount of at least the first and second doses. When two doses of 0.3mL of 1.0mg/mL epinephrine solution are delivered, the amount of epinephrine solution in ampoule 12 is at least about 0.6mL, at least about 0.7mL, at least about 0.8mL, at least about 1.0mL or more. In embodiments in which two doses of 0.15mL of a 1.0mg/mL epinephrine solution are delivered, the amount of epinephrine solution in ampoule 12 is at least about 0.3mL, at least about 0.4mL, at least about 0.5mL, at least about 0.6mL, at least about 0.8mL or more. The exact amount of epinephrine will be determined by one of skill in the art taking into account factors such as the dead volume of the syringe, etc.
In syringe subassemblies 10 and 11, ampoule 12 includes a rear end 13, which rear end 13 may be capable of being opened to slidably receive plunger 14. The plunger 14 and plunger stopper (not shown) may be moved axially in the chamber 15 of the ampoule 12 by applying an axial force to the plunger shaft 61. When the plunger 14 is compressed toward the forward or needle end, i.e., toward the needle 17 (fig. 1), 24 (fig. 2), the plunger 14 may thereby force the epinephrine solution out through the hollow needle assembly 16 at the forward end of the ampoule 12.
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 epinephrine in the ampoule 12 and may eject epinephrine solution in response to forced fluid expelling motion 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 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 the seal 23 is pierced, the epinephrine solution in the ampoule 12 may be forced through the needle 24 or the needles 22 and 24 when an injection is administered.
The dual needle subassembly 11 may also use a protective needle shield 19. The sheath 19 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 cover, as disclosed in 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 earlier U.S. patents US5,358,489 and US5,665,071.
Injection device
Overall construction
In the drawings a hypodermic injection device 30 according to the invention is shown. The injection device 30 (fig. 3-6) includes a barrel 31 having a nozzle end 32 with a needle-receiving bore 34 that is a passageway that allows the needles 17, 24 to pass through. A syringe subassembly receiving chamber 35 is disposed along barrel 31 and within barrel 31, preferably near nozzle end 32 and accessible from nozzle 32. The chamber 35 is adapted to releasably or slidably receive the syringe subassembly 10 or 11 for movement toward or away from the nozzle end 32. The needle assembly 16 is aligned to project through the needle receiving 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 control 38 or other penetration control 38 is also advantageously provided. The penetration controller 38 may include a penetration control abutment surface 39 that may engage the ampoule 12 assembly, such as on a shoulder or other suitable feature. The penetration control 38 is of a suitable length and configuration relative to the 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. Barrel 31 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, the driver spring guide 33 serves to guide the extension and retraction of the syringe driver spring 36. The drive spring 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 embodiment, the barrel rear end 41 is adapted to mount a firing bushing 43, the firing bushing 43 being an annular end piece, and used in conjunction with the driver 36 (the details of which will be further described below). 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 nozzle end 32 mounts a detachable nose cap 45, the nose cap 45 including a needle aperture 34 or other passageway through which the forward needle 17 extends when fired. The bore 34 of the nose cap 45 is connected to the barrel by internal assembly threads 46, a ring or other protrusion, which together allow the nose cap 45 to be removed from the nozzle end 32. The nose cap 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 rod 61 of the needle subassembly 10 or 11 or is connected to the plunger 14 of the needle subassembly 10 or 11 via the plunger rod 61. Plunger rod 61 may be separate from or integral with plunger 14 and acts as a piston to push the epinephrine solution through the interior cavity of syringes 10, 11 and out of needle 17. The driver 36 is capable of forcing the subassembly in a forward direction to effect needle penetration and act on the plunger 14 to inject the epinephrine solution content of the ampoule 12. The force is applied automatically by a spring or by other suitable user-initiated trigger-operated actuator force.
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, further suitable drivers are presented herein that include 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 that when released can 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 37 (in this figure, the shaft) as an example provides a spring engagement shoulder 52 (see fig. 3) against which the front end 51 of the actuator spring 50 engages. As shown, the driver release 53 includes one or more barbs 54 that fit into a central aperture 114 of the firing bushing 43. Barbs 54 are preferably formed on the flexible end of the actuator release 53 similar to the legs of the actuator stem 37.
A safety, advantageously in the form of a safety cap 55, has a forwardly projecting pin 56 received between the legs of the driver release 53 to retain the barbs 54 in engagement with the firing bushing 43 to prevent forward movement of the driver rod 37 through the aperture 114 until the safety 55 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 actuator rod 37. 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 typical actuator lever 37 having four legs (including a release 53), but other numbers are also contemplated. In some embodiments, the actuator rod 37 is preferably made using two parts 37a and 37b that fit together. These portions 37a and 37b may alternatively be made of metal and formed as a single piece 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 sleeve 57 may include a groove 58 formed on the forward end of the barrel 31 that gradually sinks along a stop 59 (see FIGS. 4-6, 9, and 10). The retainer 59 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 57 from being inadvertently removed from the barrel 31. 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. In some embodiments, 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 61 such as formed by portions 62 and 63, dose control is more accurate because each ampoule 12 can be varied in length and the adjustability can be adjusted to accommodate the variation.
Dose adjustment
The automatic injection device according to the present invention 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 (0.3mL or 0.15mL of epinephrine solution) has been expelled from the syringe subassembly 10 or 11.
After injection of the first dose (0.3mL or 0.15mL of epinephrine solution), the second dose remains in ampoule 12 after the first injection. The syringe subassembly 10 or 11 may be removed from the barrel 31 to access the collar 64, and then the collar 64 may be removed from the plunger rod 61 to allow further movement of the plunger 14 to deliver an additional dose.
After removal of the syringe and collar, the syringe 10 or 11 may be used to manually inject a second dose of epinephrine solution. The needle is first inserted subcutaneously or intramuscularly into the patient. The plunger rod 61 is then depressed by the thumb or finger in the direction of the needle 17, thereby injecting the epinephrine solution (0.3mL or 0.15mL) into the patient.
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 61.
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 the earlier embodiments. 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.
Head cap or nozzle end piece
Fig. 6 shows the nose cap 45, which is advantageously detached from the barrel 31 to allow insertion and removal of the syringe subassembly 11. It is particularly desirable that the nose cap 45 be removable to allow retraction of the syringe subassembly 10 or 11 to allow manual injection of the second dose of epinephrine solution as described herein. The nose cap 45 may be generally cup-shaped to be received over the forward end of the barrel 31. In the illustrated embodiment, the nose cap 45 fits over the outward surface of the barrel 31. The nose cap 45 is attached to the surface using threads 46 or other suitable connectors. Depending on the particular configuration used, the nose cap 45 may alternatively fit within the barrel 31.
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 nose cap 45 on barrel 31. This is desirable because the nose cap 45 can be repeatedly removed and reinstalled, enabling removal and replacement of the ampoule 12 and needle sub-assemblies 10, 11.
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 34 as shown, which is advantageously arranged to receive the needle shield 19 therein. As shown in fig. 9 and 10, the needle safety shield 19 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 45 from the barrel 31. The illustrated construction uses a threaded connection between the nose cap 45 and barrel 31. An external friction surface that allows torque to be applied is therefore preferred in this configuration. The preferred rubbing surface has minute linear longitudinal striations (not shown).
Sheath remover 80
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 38
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 38 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 45 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 controller 38 is incorporated by the syringe assembly to stop forward movement of the muscle puncture 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 lancing control 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 45 may also result in removal of the penetration controller 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 within the barrel 31 and relative to the outer front face of the nose cap 45 or other muscular interface of the syringe. The thickness of the flange sleeve 70 and the flange 170 define the length of the controller 38. The end of the sleeve 70 opposite the flange provides the 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 needle subassembly 11 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 70 may therefore be used for subcutaneous injections and the other may be selected when deeper muscle penetration is required. The choice of different axial length sleeves 70 may be used depending on the drug being provided into the syringe or the particular needle penetration depth desired.
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 31 between the nose cap 45 and the needle hub 90. A forward or return spring 71 is provided to yieldably resist forward movement of needle subassembly 11, holding subassembly 11 in the retracted position until syringe driver 36 is triggered. The return spring 71 also helps reduce contact of the syringe assembly with the penetration controller 38, thereby reducing or eliminating breakage of the hub 21 or penetration controller 38.
The penetration controller 38 may be used to connect the return spring 71 in position in the barrel 31 using the flange 170. This also helps to retain the return spring 71 for removal with the hood 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 71 is to maintain the needle 17 in the retracted position, which is concealed, after the sheath 19 is pulled off. This prevents the user from seeing the needle 17 and from being frightened by the needle. The return spring 71 acts quickly to remove the shield 19 to return the barrel 11 up into the barrel 31 so that the user does not see the remainder of the needle 17 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 70. 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 sleeve 70 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 11 for replacement or a second injection need only unscrew the nose cap 45 from one end of the barrel 31. The return spring 71 and sleeve 70 will move with the nose cap 45 to allow free access to the cavity 35. The leaves 170a may interact with the internal threads of the nose cap 45 when disconnected from the barrel 31 to help prevent free fly motion of the nose cap 45, sleeve 70 and forward spring 71.
Second exemplary lancing control device 38
Another form of penetration controller 38 may be provided in the following form and configuration: using a dedicated selected spring 71 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 21 engages or against which other components engage (as will be explained further below). Hub 21 will stop when spring 71 is fully compressed and the desired penetration depth is reached.
By using springs 75, 76, 77 selected for the desired compression length, the springs themselves become penetration controls 38 when fully compressed between needle hub 21 and 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 75-77 may be friction fit in nose cap 45 to hold springs 75, 76, 77 and nose cap 45 together. This simplifies access to chamber 35 and needle assembly 11 therein. It also mitigates rapid movement temporary discharge of the nose cap 45 and spring 71 when disconnected. Thus, the cover 45 and spring 71 may be assembled so that both may be removed from the bucket 31 as a unit at the same time. Changing one spring for another to accommodate different penetration depths is a simple matter of removing nose cap 45 from barrel 31 and changing springs 75 through 77. Alternatively, an assembly comprising the nose cap 45 and the different springs 75 to 77 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 drive 36 through syringe assembly 11. 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. The portion 78c is an enlarged end coil or wire that contracts radially when installed in the receiving portion of the nose cap 45 and serves to tie the spring 78 and nose cap 45 together.
By adjusting the relative proportions of portions 78a, 78b and 78c, the compression and energy absorption characteristics of forward spring 78 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 increased number of inelastic coils therefore results in less energy being absorbed by the forward spring and allows the driver to better retain sufficient energy for injecting and dispensing the medicament.
Fig. 15E shows the spring 78 in a fully compressed but axially aligned and stacked state. This occurs when the spring 78 has stronger and/or larger spring wires. The spring 78 made of the stronger wire will thus reach a fully compressed state and then stop fairly abruptly at the exemplary penetration depth for that spring 78 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 79 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 79 compress into a typical or near typical stacked arrangement. In a second phase or period, the spring 79 twists and the various windings are forced to change radially, thereby twisting and collapsing and some windings move inside or overlap others. 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 from the syringe hub 21 and other portions of the injector 30. It also provides a buffer when the syringe and drive 36 decelerates 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 presently the preferred wire sizes for injection devices that use only a spring as the penetration controller 38. 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 having a tubular sleeve 70 and flange 170 or other similar relatively inelastic penetration controller 38 elements. 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.
Front spring load distribution, guidance and damping for syringe assemblies
Fig. 24 and 25 show the front of an injection device 30 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 syringe assembly hub 21 in barrel cavity 35. 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 to the same size as the portion of the barrel cavity 35 in which the load distribution ring 171 (acting as a guide ring) moves 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 member 171. This allows the gasket to expand radially outwardly as the syringe is driven against the front spring 75 and a resistance is created in relation to the fluid medicament dispensed from the front needle 24 when a load is applied thereto. An outside diameter greater than and close to the inside diameter of an adjacent barrel can cause lateral strain that causes frictional resistance to the gasket 172 with the barrel cavity 35. 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 pad 172 bears directly on the syringe hub 21 and the front spring 75. 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.
Functional summary of front return spring
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 carriage by a user and otherwise. 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 breaking the syringe ampoule 12.
The return spring also serves to help retain the needle inside the hood or barrel 31 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 barrel 31, kinetic energy and stored spring energy are preferably dissipated to prevent or reduce the risk of breaking the syringe ampoule 12 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 seal 23 of the ampoule 12. This is achieved by selecting a return spring that generates the required return force that provides for a delayed injection of the medicament until the needle penetration depth is correct.
In some versions of the invention, a front or return spring itself may be used as the penetration controller 38. This simplifies the construction of the injector and saves cost, wherein the desired consistency of the penetration controller 38 for the medicament is within the exemplary consistency of the penetration controller 38 spring to be used, which is desirable. Wherein these parameters are not required to conform to the more complex sleeve 70 of the penetration controller 38.
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 double-needle syringe subassemblies
The description in this regard is more general with respect to the needle subassemblies 10, 11, as both needle forms can be used with 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 subassembly 11 is advanced, hub 21 slides into abutment with 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, continued forward force on the syringe subassembly 11 by the driver 36 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 12 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 ampoule 12 through the needle 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 38 to perform the final placement and insertion of the needle 22 through 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 11 to seat or mate with the sealed ampoule 12. 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 the double syringe assembly 11 with the sealed ampoule 12 to form a manual dose from the double syringe and sealed ampoule 12. 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 manual administration may be controlled due to ultimate reliability when the patient is far from the medical facility (such as in rural remote areas, in field-of-war situations, or other difficult situations where professional medical care cannot be quickly or conveniently obtained).
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 210 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 the syringe 30 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 80 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 19 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 that does not allow the syringe 30 to be loaded (compressed) in an axial manner when stored in the carrying case.
Fig. 28 shows that the upper portion 202 of the carrying case 200 is advantageously provided with a clip mount 206 that can be welded to the upper portion 202 or integrally formed therewith when the upper portion 202 is formed. The clip holder 206 is used to hold a clip 207 similar to a clip on a pen. The clip 207 is preferably made of metal having a spring characteristic that keeps the clip end 208 against the upper box portion 201. The clip 207 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 other piece of 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 202, 201 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 241 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. External member
The invention also includes the injection of epinephrine to a patient in need thereof, such as a patient experiencing an allergic reaction, an anaphylactoid reaction, or a group of symptoms similar to an allergic reaction or anaphylactoid reaction of unknown etiology but suspected of requiring an allergic emergency. The kit includes an autoinjector according to the present invention and other items when needed to ease the injection of epinephrine to a patient.
In some embodiments, kits provided according to the invention include a syringe according to the invention and printed instructions for use of the kit. In some embodiments, the printed instructions include one or more instructions related to performing one or more of the operations described above. In particular, printed instructions include instructions configured to perform one or more of the following functions: (1) removing the end cap 45; (2) the safety cap 55 is removed; (3) applying the hood 45 to the thigh or other thick musculature with sufficient force to automatically trigger the release 53 to actuate the device 30 and inject the epinephrine solution into the patient; (4) removing the hood 45; (5) withdrawing the syringe subassembly 10, 11 from the syringe barrel 35; (6) removing the collar 64; (7) inserting the needle 17 into the patient; (8) manually depressing the plunger 14, thereby injecting the epinephrine solution into the patient; (9) withdrawing the needle 17 from the patient; (10) placing the needle subassembly 10, 11 back into the container 200; and (11) safe disposal of the container 200 containing the used needle subassembly 10, 11. Other instructions are also included within the scope of the present invention. The written way of the instructions is to convey the necessary information: self-injecting by the patient the first and/or second dose; injecting the first and second doses into the patient by someone other than the patient; and self-injecting the first or second dose in combination with injecting the first or second dose into the patient by someone other than the patient.
In some embodiments of the invention, a kit according to the invention comprises a container 200 according to the invention. The kit is provided with the device 30 in a container 200. The kit is provided with additional protection for ampoule 12 and hub 21 or 90 in device 30. In addition, the kit provides a convenient package for carrying the automatic injector 30. In some embodiments, the container 200 may be resistant to moisture and even water; and may in some cases be sufficiently buoyant to enable the kit to float when properly assembled, thereby providing a suitable and convenient package for transporting the device 30 under extreme conditions, such as kayaking, canoeing, and other water sports.
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 bar 37 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 release the driver rod or shaft 37. This prepares the apparatus for receiving the selected syringe assembly.
The process then involves selecting an appropriate syringe subassembly 11, which is preferably pre-loaded with an epinephrine solution as described herein. 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 11, as described herein, 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 expelled volume or dose (0.3mL or 0, 15mL of epinephrine solution, depending on the size and/or age of the target patient). 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 11 through the open forward end of barrel 31. The method further includes positioning and mounting the syringe subassembly 11 to a desired location within the interior of the barrel 31. This is accomplished by removing the nose cap 45 and sliding the selected syringe subassembly 11 having the first open end 13 into the barrel cavity 35.
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 the penetration may be accomplished by selecting a desired penetration controller 38, spring penetration controller 38, or other penetration controller 38 having a length that positions the abutment surface 39 at a desired location. 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 45 or by disposing selected penetration controller 38 springs 75-79 in the nose cap 45. 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. The return spring 71 is also disposed in the sleeve 70 prior to installation of the controller and spring subassembly 11 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 38 and nose cap assembly 45 may then be mounted to the barrel 31. This is advantageously accomplished in the illustrated embodiment by threading 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 21 or 90. The return spring 71 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 11.
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, positioning the sheath engagement fingers 82 over the sheath 19. The fingers 82 will flex allowing the sheath remover 80 to act by sliding over the length of the needle sheath 19 of the nose cap 45 that is exposed forwardly.
Once the nose cap 45 and sheath remover 80 are in position and the safety 55 is connected, the device 30 is loaded, cocked and in a near-ready-to-use safe state. The device 30 can be safely carried or stored in this state until the moment of injection. In some embodiments, the device 30 is placed in the container 200 in the manner described above.
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 double needle assembly 11, but the latter is believed to have some advantages, including increased shelf life of the epinephrine solution.
Prior to injection, the user may remove the protective sheath 19 from the needle subassembly 11 by movement, such as by sliding the sheath remover 80 forward. This performs a disengagement step to disengage the sheath remover 80 from the nose cap 45. The fingers 82 of the sheath remover 80 engage and capture or bond with the sheath lip 89. Further removal of the sheath remover 80 applies an axial force to the sheath 19 by pulling the sheath 19 outwardly through the needle aperture 34 in the nose cap 45. The sheath remover 80 thereby performs the action of removing the sheath 19 from the syringe assembly and other parts of the auto-injector.
The user may perform a removal step to remove the safe 55 from the opposite end of the tub 31. 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 31. Barbs 54 on drive bar 37 or the shaft assembly will move toward one another by engaging barbs 54 against the walls of openings 60 to collapse inwardly. This action releases the actuator rod 37, which is now permitted to move forward, such as by sliding, in response to the force applied by the actuator 36. The urging of the driver rod 37 serves to free the driver release 53 into a driving action in which the driver rod 37 moves forward and acts by engaging the plunger rod 61. The driving action also urges the needle subassembly 11 forward. This is done by piercing the patient's adjacent tissue with the needle 24 (which may be the same person as the user who self-injects the epinephrine solution, or may be injected by a person other than the user), and also by piercing any second needle 22 through the ampoule 12 seal.
When the needle subassembly 11 is moved forward, the return spring 71 or the selected penetration control springs 75 to 79 are acted upon to perform the compression of the forward spring. Spring 71, nose cap 45 and any penetration control 38 are acted upon by needle hub 21 or 90 which re-limits and stops forward movement. 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 38, 70. The penetration depth is determined by the selected axial position of the abutment surface (whether or not it is on the penetration controller 38 sleeve) or by fully collapsing the spring of the desired fully compressed length.
Once the abutment surface or the full spring compression point is reached, the drive spring 50 will continue to push the plunger rod forward to dispense epinephrine solution (0.3mL or 0.15 mL). Where a single syringe subassembly 11 is used, continued forward movement of the plunger 14 will result in the injection of the epinephrine solution, which is also injected when the dual needle assembly 11 is provided in the barrel 31 but after the ampoule 12 is driven forward onto the seal piercing needle 22.
The epinephrine solution is injected when the spring 36 urges the plunger 14 forward. The actuation continues until such time as the plunger shaft engaging head 63 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 injection penetration depth. The device is now ready to remove the nose cap 14 to use the syringe assembly 10, 11, allowing manual injection of a second dose of epinephrine (0.3mL or 0.15mL) after removal of 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 new method may further comprise performing a second manual injection. This is accomplished using the same syringe assembly as used in the first automatic injection. First, the syringe assemblies 10, 11 are removed from the barrel 31 in the same or similar manner as described above. If the initial dose does not work sufficiently effectively, the user (patient or someone other than the patient) can manually insert the forward needle into the patient's muscle and use the thumb to depress the plunger rod.
While preferred embodiments have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. The following claims define the method of the invention and methods and structures within the scope of these claims and their equivalents are covered thereby.