Abstract
A reloadable auto injector includes a syringe with a needle movably positioned in a housing between a first position with the needle inside the housing and a second position with the needle protruding outside the housing. A plunger rod advances in the syringe for delivering a dose of medicament. A plunger rod tube having deflectable locking members interacts with a plunger rod stop to lock the plunger rod. A syringe driver moves the syringe from the first position to the second position. The syringe driver advances the plunger rod tube with the plunger rod to the second position. A plunger rod driver advances the plunger rod in the syringe for delivering a dose of medicament upon unlocking each of the deflectable locking members. A reload mechanism retracts the syringe from the second position to the first position and reloads for repeated activation of the syringe driver.
Claims
1. A reloadable auto injector having a housing (500) for accommodation of: a syringe (1000) with a needle, the syringe being movably positioned in the housing (500) between a first position in which position the needle is accommodated inside the housing (500) and a second position in which position the needle protrudes outside the housing (500), a plunger rod (1500) configured to be advanced in the syringe for delivering at least one dose of medicament, a plunger rod tube (1100) having two or more deflectable locking members (1108) configured to interact with a plunger rod stop (1508) to normally lock the plunger rod (1500) to the plunger rod tube (1100), a syringe driver (1200) configured to apply a force to the syringe (1000) thereby moving the syringe (1000) from the first position to the second position, the syringe driver (1000) being further configured to advance the plunger rod tube (1100) with the plunger rod (1500) to the second position, a plunger rod driver (1600) being configured to apply a force to the plunger rod (1500) to advance the plunger rod (1500) in the syringe (1000) for delivering one dose of medicament upon unlocking of each of the two or more deflectable locking members (1108), wherein the a plunger rod (1500) is hollow and the plunger rod driver (1600) extends inside the hollow plunger rod (1500).
2. A reloadable auto injector according to claim 1, further comprising: a reload mechanism configured to retract the syringe from the second position to the first position and reload the syringe driver to allow a repeated activation of the syringe driver, wherein the reload mechanism, the reload mechanism comprising activation of the auto injector for a further injection, requires an operator input,
3. A reloadable auto injector according to claim 2, wherein the reload mechanism is configured to unlock a first deflectable locking member (1108) upon a first movement of the syringe (1000) from the first position to the second position to thereby release the plunger rod (1500) from the plunger rod tube (1100) for delivering a first dose of medicament, and unlock a further deflectable locking member (1110) upon a further movement of the syringe (1000) from the first position to the second position to thereby release the plunger rod (1500) from the plunger rod tube (1100) for delivering a further dose of medicament.
4. A reloadable auto injector according to claim 1, further comprising a plunger rod driver guide (1700) extending inside the plunger rod driver (1600), the plunger rod driver guide (1700) being configured for guiding the plunger rod driver (1600) inside the hollow plunger rod (1500).
5. A reloadable auto injector according to claim 4, wherein the plunger rod driver guide (1700) is made from stainless steel.
6. A reloadable auto injector according to claim 3, wherein the housing further comprises a reload handle (1400), wherein the handle (1400) has a first opening configured to be aligned with the first deflectable member when the plunger rod tube (1100) is advanced to the second position a first time and a further opening configured to be aligned with the further deflectable locking member when the plunger rod tube is advanced to the second position a further time.
7. A reloadable auto injector according to claim 2, wherein the reload mechanism is connected to the syringe and the plunger rod tube so that user operation of the reload mechanism is configured to retract the syringe and the plunger rod tube to the first position and to simultaneously reload the syringe driver to thereby ready the auto injector for delivering a further dose of medicament.
8. A reloadable auto injector according to claim 1, wherein the plunger rod driver (1600) and the syringe driver (1200) are separate drivers.
9. A reloadable auto injector according to claim 1, wherein the plunger rod driver (1600) and the syringe driver (1200) are partly displaced.
10. A reloadable auto injector according to claim 1, wherein the plunger rod driver (1600) is longer than the syringe driver (1200).
11. A reloadable auto injector according to claim 1, wherein the syringe driver (1200) is provided outside the plunger rod tube (1100) and the hollow plunger rod accommodating the plunger rod driver (1600) is provided inside the plunger rod tube (1100).
12. A reloadable auto injector according to claim 1, wherein the auto injector is configured to deliver two separate doses of medicament.
13. A reloadable auto injector according to claim 12, wherein the plunger rod driver (1600) is configured to move the hollow plunger rod (1500) a first distance upon a first activation of the plunger rod driver, and a further second distance upon a second activation of the plunger rod driver.
14. A reloadable auto injector according to claim 1, wherein the auto injector is activated upon unpacking of the device.
15. An auto injector according to claim 1, wherein the syringe driver (1200) and/or the plunger rod driver (1600) comprises a resilient device, such as a spring, such as a compression spring.
16. An auto injector according to claim 1, further comprising a skin sensor (700), the skin sensor having a locked forward position and an unlocked forward position.
17. A reloadable auto injector according to claim 16, wherein the skin sensor is unlocked in the forward position before a first injection and/or upon operation of the reload handle.
18. A reloadable auto injector according to claim 1, further comprising a syringe lock (600) configured to lock the syringe (1000) in the first position, and a skin sensor (700) configured to release the syringe lock upon engagement with the skin of a user wherein the skin sensor is activated by pressing the skin sensor onto a user's skin.
19. A reloadable auto injector according to claim 18, wherein the syringe lock controls the injection of the needle.
20. A reloadable auto injector according to claim 18, wherein the plunger rod tube (1100) comprises a plunger rod tap being configured to move in a syringe lock guide slot from a released position adjacent the ledge to a syringe lock end stop and wherein the plunger rod tube, engaged with the syringe, is moved from the first position to the second position when the plunger rod tab travels in the syringe lock guide slot from the released position to the syringe lock end stop.
21. A reloadable auto injector according to claim 18, wherein a skin sensor driver (800) upon removal of the auto injector from a patient's skin is configured to push the skin sensor forward to shield the needle before and after each injection cycle.
22. A reloadable auto injector according to claim 1, wherein the reload mechanism comprises a reload handle (1400) configured to rotate, the auto injector further comprising an intermediate component (torsion ring) (1800) transferring the rotational movement of the reload handle to a translational movement of at least the syringe assembly (1000) and wherein the intermediate component (1800) has a tap (1802) configured to move along an inclined surface of the reload handle (1402) upon operation of the reload handle (1400).
23. A reloadable auto injector according to claim 22, wherein a complete operation of the reload handle forces the tap over an inclined surface top and into a second reload handle slot (1404).
24. A reloadable auto injector according to claim 23, wherein the syringe and the plunger rod tube (1100) is configured to rest on a syringe lock ledge (1002) when the intermediate component tap reaches the second handle slot.
25. A reloadable auto injector according to claim 23, wherein the second reload handle slot (1404) has an inclined surface to allow for continuous reloading to the auto injector.
26. A reloadable auto injector according to claim 23, wherein the second reload handle slot (1404) allows for longitudinal movement only to thereby prevent further reload of the auto injector.
27. A reloadable auto injector according to claim 1, wherein the reload operation is configured to reverse the operation of the auto injector.
28. A reloadable auto injector according to claim 1, wherein the auto injector housing further comprises an inspection window for indicating a ready state and a done state of the auto injector.
29. A reloadable auto injector according to claim 16, wherein the skin sensor extends over the length of the needle when the syringe assembly is in the first position to hide the needle from a user's and/or patient's view.
30. A reloadable auto injector according to claim 29, wherein the skin sensor is configured to extend over the length of the needle immediately after a dose has been delivered.
31. A reloadable auto injector according to claim 1, wherein the auto injector further comprises an anti-tampering component.
32. A reloadable auto injector according to claim 311, wherein the anti-tampering component comprises a ratchet mechanism.
33. A reloadable auto injector according to claim 32, wherein the syringe is replaceable.
34. A reloadable auto injector for epinephrine injection comprising separate needle insertion driver and medicine injection driver wherein needle insertion driver action is configured to be re-activated upon reloading.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0120] FIG. 1 shows an exploded view of an auto injector,
[0121] FIGS. 2A-G show exemplary a view of the auto injector in various states as seen from a user perspective,
[0122] FIGS. 3A-C show indicators in different states,
[0123] FIGS. 4A-C show an auto injector handle top and corresponding casing,
[0124] FIGS. 5A-G show a cross sectional view of an auto injector according to the invention during different stages of operation,
[0125] FIGS. 6A-F show a reload handle, plunger rod tube and plunger rod in various stages,
[0126] FIGS. 7A-C show details of a skin sensor,
[0127] FIGS. 8A-B show a detailed view of an inspection window,
[0128] FIGS. 9A-F show a reloading mechanism according to the present invention,
[0129] FIGS. 10A-E show a syringe lock guiding trail in various stages,
[0130] FIGS. 11A-B show a reload handle for single or repeated delivery of doses,
[0131] FIG. 12 shows a syringe assembly in more detail,
[0132] FIG. 13 shows a cross-sectional view of the protective casing,
[0133] FIGS. 14A-C show the recap prevention cap and the recap prevention spring.
[0134] FIG. 15 shows a view of the lower part of the auto injector.
DETAILED DESCRIPTION OF THE DRAWING
[0135] In the following an auto injector according to any of the above described aspects of the disclosure will be described in more detail and with reference to the drawings. A reloadable auto-injector 10 with a housing 500 for accommodation of a syringe assembly 20 is provided. The syringe assembly 20 may comprise a syringe 1000 with a needle 1002, and the syringe assembly 20 may be movably positioned in the housing 500 between a first position in which position the needle 1002 is accommodated inside the housing 500 and a second position in which position the needle 1002 protrudes outside the housing 500. The syringe assembly 20 may further comprise a syringe stopper 1004 movably positioned in the syringe 1000 and sealing the syringe content 1006. The auto-injector further comprises a plunger rod 1500 configured to engage the syringe stopper 1004, and a plunger rod driver 1600 being configured to apply a force to the plunger rod 1500 to advance the plunger rod 1500 in the syringe 1000 for delivering at least one dose of medicament. Furthermore, a syringe driver 1200 may be accommodated inside the housing 500 and be configured to apply a force to the syringe assembly thereby moving the syringe 1000 from the first position to the second position. The housing 500 may still further comprise a reload handle 1400 configured to reload the auto injector 10 for injecting a further dose of medicament, wherein the reload handle 1400 may be connected to the syringe assembly 20 so that user operation of the reload handle 1400 is configured to retract the syringe assembly 20 to the first position and to simultaneously reload the syringe driver 1200 to thereby ready the auto injector 10 for delivering a further dose of medicament.
[0136] In FIG. 1 an exploded view of an auto-injector according to an embodiment of the present disclosure is provided. A protective cap in the form of a casing 100 is provided as a transport casing and is configured to be removed by the user before use of the auto injector 10. A rigid needle shield remover 200 preferably cooperates with the casing 100 and the rigid needle shield 950 so that the rigid needle shield remover 200 may be easily removed with the casing 100.
[0137] The auto injector has a housing 500 configured to enclose the further auto injector parts, including the syringe lock 600 and the skin sensor 700 which parts cooperate to release and lock the needle shield 950 and the syringe assembly 20. The skin sensor driver 800 may be a spring. The syringe tube is provided to accommodate the syringe 1000 with needle (not visible in FIG. 1), and is interconnected to the plunger rod tube 1100. A syringe driver 1200 is configured to act on the syringe 1000 in the syringe tube 900. Housing lock ring 1300 interconnects the housing 500 and reload handle top 1900. The reload handle 1400 is interconnected with the handle top 1900 and allows for reloading of the device, in co-operation with syringe lock 600 and skin sensor 700 as further described below. The plunger rod driver 1600 is configured to apply a force to the plunger rod 1500 and protrudes inside the hollow plunger rod 1500 in the assembled state.
[0138] Torsion ring 1800 transmits the rotational movement of the handle top 1900 to a translational movement of the syringe assembly. Handle top 1900 is positioned at an end of the auto injector, and is configured to be rotated with respect to the housing 500 upon reloading of the device.
[0139] The auto injector 10 may also comprise a recap prevention cap 300 and one or more recap prevention springs 400 positioned outside and around the front end 506 of the housing 500, i.e. the housing is partly protruding through the recap prevention cap (300) with the recap prevention springs (400). Inside the protective casing 100 is a first casing recess 102 (see FIG. 13) which is configured for interacting with the one or more recap prevention springs 400 if the protective casing 100 is pushed onto the auto injector again after removal of the casing 100. This is on order to prevent that the auto injector can be fully inserted inside the protective casing 100 once the protective casing has been removed from the auto injector.
[0140] FIG. 2 illustrates the auto injector in various use states as seen from the point of the user or patient. In FIG. 2A, the auto injector 10 is enclosed in casing 100 and the casing 100 is adjoining handle top 1900. In FIG. 2B, the casing 100 is removed and auto injector 10 has become visible. The auto injector 10 comprises housing 500 having an inspection window 502 and a skin sensor 700. A medicament 1006 in the syringe 1000 is visible through the inspection window 502, as indicated by the dark color of the window thereby indicating to a user that the auto injector is ready to use. The handle top 1900 is configured to interact with reload handle 1400 which is partly visible below the handle top 1900 in FIG. 2B. The skin sensor 700 is in an extended forwards position, completely shielding the needle. In FIG. 2C, the skin sensor 700 is pushed slightly backwards in relation to the skin of a patient, and the needle 1002 is visible in the skin sensor opening 702. The automatic needle insertion is not yet activated. In FIG. 2D, the skin sensor 700 is pushed backwards and is in the retracted position, and the automatic needle insertion has been activated so that needle 1002 protrudes from the skin sensor and the tip of the syringe 1000 is visible in the skin sensor opening 702. In this position, the needle 1002 is configured to be inserted into the skin of a patient. When the user removes the needle 1002 from the skin after injection, the skin sensor 700 is pushed forward and shields the needle 902. The needle sensor 700 is in a locked position. It is seen that in neither of the FIGS. 2C to 2E is the medicament visible through the inspection window 502 thereby indicating to a user that the device is not in an initial position ready to deliver a dose. In FIG. 2F, the auto injector 10 is re-loaded by turning the handle top 1900 with respect to the housing 500, the skin sensor 700 is in an unlocked position and the medicament 1006 in the syringe 1000 is visible through the inspection window 502. In FIG. 2G, the skin sensor 700 is in a locked position after a second dose has been delivered, and the inspection window 502 indicates that the device is not in a ready position.
[0141] In FIG. 3, indicator windows 502, 504 are provided. The auto injector 10 may alternatively only have the inspection window 502. The inspection window 502 and the label window 504 of auto injector 10 is shown in more detail. In FIG. 3A, the auto injector 10 is in a ready state with the cap and casing removed. The inspection window 502 is open and thus exposes the medicament 1006 in the syringe 1000 and the skin sensor driver 800 is furthermore visible through the window. It is seen that the skin sensor 700 is in the unlocked forward position and the device is ready to deliver a dose, as is also indicated by label window 504 reading READY. In FIG. 3B, the needle 1002 has been injected into a patient's skin 2000. The skin sensor 700 is fully retracted and the housing 500 is resting on the patient's skin 2000. The inspection window 502 is closed and does not reveal the medicament, and the label window 504 has the reading DONE when the dose has been injected. In FIG. 3C, the skin sensor 700 is fully extended and is in the locked forward position and skin sensor lock tabs 708 are visible. The inspection window 502 is closed and the label window 504 still has the reading DONE. It is seen that during the injection process, the needle 1002 is not visible for the user or the operator activating the auto injector 10 and the skin sensor 700 also acts as a needle shield or needle shroud. It is seen from the FIGS. 2 and 3 that the overall length of the auto injector is not significantly increased when delivering a further dose and it is a benefit of the present disclosure that a compact auto injector is provided which is capable of delivering one or more doses. The compact size is obtained due to the reversible features of the auto injector as further described below.
[0142] FIG. 4 shows the mechanism for removing casing 100 in more detail. As seen in FIG. 4A, the casing 100 is adjoining the handle top 1900. The casing may be held in place by a ring snap mechanism in place between the handle 1400 and the casing 100. The casing 100 and the handle top 1900 may be sealed by a piece of adhesive tape (not shown) wrapped around the casing 100 and handle top 1900 assembly. Upon activation, that is when the user unpack the auto injector 10, the casing 100 is removed from the auto injector 10 by twisting it slightly against the handle top 1900, utilizing a tapered knob 1402 on the auto injector, such as on the reload handle 1400 to translate the rotational force into a longitudinally movement which breaks adhesive as shown in FIG. 4B. In FIG. 4B, in which the casing is slightly turned to break the seal and disengage the ring snap mechanism. The casing 100 is removed partly by the rotation and partly by the longitudinal displacement following both the longitudinal movement initiated by the tapered knob 1402 and a pulling action initiated by the user.
[0143] FIGS. 5A-G show cross sectional views of an auto injector in a number of injection stages. In FIG. 5A, the auto injector is in a storing stage. The auto injector 10, apart from the handle top 1900 is encompassed in casing 100. The RNS 950 and the RNS remover 200 are in position to protect the needle 1002 and facilitate removal of the RNS 950, respectively. The hollow plunger rod 1500 is in an initial position and a forward end 1510 of the hollow plunger rod 1500 is positioned at a distance from a syringe stopper 1004 surface. Thereby, a slight accidental movement of the plunger rod 1500 will not impact the syringe stopper 1004.
[0144] In FIG. 5B, the casing 100, the RNS 950 and the RNS remover 200 have been removed from the auto injector shown FIG. 5A.
[0145] In FIGS. 5C and 5D, the auto injector is shown immediately before injection of a first dose and immediately after the injection of a first dose, respectively. In FIG. 5D, the needle 1002 is exposed and inserted into the skin of a patient (not shown) and the hollow plunger rod 1500 has been moved forward under influence of plunger rod driver, i.e. spring, 1600, so that the protrusion 1508 of the plunger rod rests against a first stop 1108 of the plunger rod tube 1100, see further details in FIG. 6. The stopper 1004 has been moved forward to expel a first dose of medicament and the skin sensor 700 is the retracted position.
[0146] After the needle 1002 has been retracted from the skin, in FIG. 5E, the skin sensor 700 is moved to a forward locked position by skin sensor driver 800. At the stage in FIG. 5E, the auto injector may be either discarded as it is or reloaded for delivering of a second or further dose.
[0147] FIG. 5F shows the auto injector 10 after reloading of the device and before firing of the second dose: The hollow plunger rod 1500 has been moved forward under influence of plunger rod driver, i.e. spring, 1600, so that the protrusion 1508 of the plunger rod 1500 rests against a second stop 1110 of the plunger rod tube 1100, see further details in FIG. 6. The stopper 1004 has been moved forward to expel a first dose of medicament and the skin sensor 700 is the retracted position.
[0148] The skin sensor 700 has been unlocked and is in the forward unlocked position, the syringe driver 1200 has been reloaded, i.e. retracted, into an initial compressed position and the syringe 1000, the syringe tube 900, the plunger rod tube 1100, the plunger rod 1500 and the plunger rod driver 1600 have been retracted without moving the mentioned parts in relation to each other.
[0149] In FIG. 5G, the auto injector is shown when the needle has been retracted from the skin after the second or further injection has been made. The plunger rod 1500 has been moved forward under influence of plunger rod driver, i.e. spring, 1600, so that the protrusion 1508 of the plunger rod rests against a second stop 1110 of the plunger rod tube 1100, see further details in FIG. 6. The stopper 1004 has been moved forward to expel a second or further dose of medicament. The skin sensor 700 is in the forward locked position and the auto injector may be discarded, a further injection may be performed or the auto injector may be re-used by for example re-fitting the auto injector with a new pre-filled syringe.
[0150] In FIGS. 5A-G, it is seen that the plunger rod driver 1600 comprises a plunger rod spring 1600. It is seen that the plunger rod driver 1600 applies the driving force directly onto the plunger rod 1500, such as onto a lower inner surface of the hollow plunger rod. In FIGS. 5A-G, it is seen that the plunger rod driver acts on the bottom of the hollow plunger rod 1500.
[0151] The housing further accommodates a syringe tube 900 for holding the syringe 1000, and the syringe has a syringe flange 1008 which is locked between the syringe tube 900 and the plunger rod tube 1100. In the present example, the syringe tube 900 and the plunger rod tube 1100 are provided as two separate units to ease assembly, however, it is envisaged that the syringe tube and the driver rod tube may be one tube holding the syringe, the plunger rod and the plunger rod driver.
[0152] It is seen that the plunger rod driver 1600 is provided inside the hollow plunger rod 1500, which in turn is provided inside the plunger rod tube 1100, and the syringe driver 1200 is provided outside the plunger rod tube 1100.
[0153] In FIGS. 6A-F, a reload handle 1400 and the cooperation with the plunger rod tube 1100 and the plunger rod 1500 is shown. Only a top portion of an auto injector as e.g. seen in any of the FIGS. 1-5 above or any of the figures is seen in FIGS. 6A-F.
[0154] The auto injector as shown in FIGS. 6A-F, is capable of sequentially control the needle insertion and dose injection. The function of the sequential control is illustrated in stages A through F
[0155] FIGS. 6A-F show the reload handle 1400, the plunger rod tube 1100 and the plunger rod 1500 in various stages of the process. The plunger rod 1500 is configured to be advanced in the syringe (not shown in FIGS. 6A-F) for delivering at least one dose of medicament. The plunger rod tube 1100 has a least one locking member 1108 configured to interact with a plunger rod stop 1508 (not visible in FIGS. 6A-F) to normally lock the plunger rod 1500 to the plunger rod tube 1100. The syringe driver 1200 is not shown in FIGS. 6A-F, however the activation of the syringe driver is illustrated by the arrows 42, 44, that is the plunger rod tube 1100 and the plunger rod 1500 are both moved forwards, i.e. from the first position to the second position. The plunger rod driver 1600 is not shown in FIGS. 6A-F, however, the activation of the plunger rod driver 1600 is illustrated by single arrow 42 illustrating that only the plunger rod is moved forward, i.e. the force applied by the plunger rod driver 1600 forces the plunger rod 1500 to advance in the syringe (not shown) for delivering at least one dose of medicament. It is seen that the housing 500, or in the present case an intermediate element 1400, i.e. the reload handle 1400, comprises an opening or an aperture 1420. The housing or intermediate element 1400 is configured to unlock the locking member 1108 and release the plunger rod 1500 from the plunger rod tube 1100 when the syringe (not shown) and the plunger rod tube 1100 is advanced to the second position, thereby activating the plunger rod driver (not shown) to advance the plunger rod 1500 in the syringe for delivering of at least one dose of medicament.
[0156] The locking member 1108 comprises at least one deflectable member 1108 and the housing 500 and/or the intermediate member 1400 is configured to allow for the at least one deflectable member 1108 to deflect away from the plunger rod 1500 when the syringe (not shown) and the plunger rod tube 1100 is advanced to the second position. Thus, it is seen in FIG. 6A that the plunger rod 1500 in the plunger rod tube 1100 is in an initial position, i.e. a first position, ready to deliver a dose of medicament. In the second position after forwards movement of the plunger rod tube 1100 and the plunger rod 1500, the plunger rod tube is in the second position. It is seen in FIG. 6B, that the plunger rod 1500 has not been moved with respect to the plunger rod tube 1100 and both the plunger rod tube 1100 and the plunger rod 1500 has been moved forwards relative to the housing or intermediate member 1400. The plunger rod driver is typically positioned inside the hollow plunger rod 1500 configured to apply a force to the bottom surface 1510 inside the hollow plunger rod 1500
[0157] The plunger rod tube 1100 and the syringe (not shown) are typically interconnected so that the plunger rod tube 1100 cannot move with respect to syringe 1000 and vice versa. The plunger rod tube 1100 may be interconnected to the syringe 1000 or the syringe tube 900, for example via plunger rod tube tabs 1110.
[0158] The housing 500 has an opening 1420, the opening 1420 being a window, or an aperture, configured to be aligned with the at least one deflectable member when the plunger rod tube 1500 is advanced to the second position. The first deflectable locking member 1108 is aligned with the window or aperture 1420 (see e.g. FIG. 6C) thereby allowing the locking member 1108 to deflect and allow passage of the plunger rod protrusion 1508, such as the plunger rod stop 1508. It is seen in FIG. 6C that upon release of the plunger rod 1500, the plunger rod driver 1600 advances the plunger rod 1500 within the syringe 1000 in that the plunger rod stop 1508 is able to pass the deflected locking member. A deflectable locking member 1108, 1110 is positioned at either side of the plunger rod, and thus also the openings 1420, 1422 are provided on either side.
[0159] In FIG. 6D, the handle 1400 is rotated as illustrated by arrow 1401 and the plunger rod tube 1100 with plunger rod 1500 is rotated and retracted to the same initial position as illustrated in FIG. 6A, while the plunger rod maintain the advanced position with respect to the plunger rod tube 1100, and the plunger rod driver (not shown in FIGS. 6A-F) also maintaining a first extended position. From this position, a second dose delivery is performed, and FIGS. 6E and 6F illustrate the repeated forward motion of the plunger rod tube with the plunger rod, as illustrated by arrows 42, 44 so as to align the second window 1422 with the second deflectable locking member 1110 and allow deflection of the locking member 1110. Thereby, the plunger rod driver 1600 is released or activated to push the plunger rod 1500 pass the second locking member 1110, for delivering of a second dose as illustrated by single arrow 42, and FIG. 6F illustrates the plunger rod in the advanced position within the syringe. The plunger rod driver is thus configured to move the plunger rod 1500 a first distance upon a first activation of the plunger rod driver 1600, and a further distance upon a further activation of the plunger rod driver 1600.
[0160] It is seen that the second activation of the plunger rod driver follows a reload of the auto injector, and thereby a repeated movement of the syringe assembly, i.e. such as syringe 1000, syringe tube 900, plunger rod 1500, and plunger rod tube 1100 from the first position to the second position.
[0161] Thus, the auto injector may deliver at least one or two separate doses of medicament.
[0162] The plunger rod stop may further have an angled surface normally pressing against an angular surface of the deflectable locking member 1108. The deflectable locking member 1108, 1110 is hinged to the plunger rod tube 1100 in a downward position with respect to the movement of the plunger rod. Hereby, the deflectable locking member may deflect only when the entire length of the deflectable locking member 1108, 1110 opposes the full opening 14.
[0163] The at least one deflectable member is configured to deflect upon being aligned with the opening in the housing 500 and/or the intermediate member 1400.
[0164] When the deflectable locking members 1108, 1110 are not aligned with the window 1420, the deflectable locking members 1108, 1110 are typically prevented from deflection by an inner surface of the handle 1400 or housing 500, such that the deflectable locking member 1108, 1110, is not entirely within the window 1420, 1422 and therefore not able to deflect.
[0165] The plunger rod tube 1100 may thus comprise at least a first and a second locking member 1108, 1110 configured to engage with the plunger rod stop 1508.
[0166] FIG. 7 shows the skin sensor 700 and the interaction of the skin sensor 700 with syringe lock 600 in more detail. In FIG. 7A, the skin sensor 700 and the syringe lock 600 are in their initial positions, and the skin sensor 700 is thus in the forward unlocked position. A protrusion 704 having an angled surface 706 is seen at the skin sensor 700. In FIG. 7B, the skin sensor 700 is activated, by e.g. pressing the skin sensor 700 against the skin of a patient, and the skin sensor 700 is moved towards the syringe lock 600. Hereby, the angled surface 706 engages with a syringe lock angled surface 612 to thereby force the syringe lock 600 to rotate while the skin sensor 700 is retracted. In FIG. 7C, the skin sensor 700 is fully depressed, i.e. fully retracted, and engaged with the syringe lock after rotation. FIG. 7D shows a detailed view of the syringe lock protrusion 704 and the angled surface 604 of the syringe lock 600.
[0167] FIG. 8 shows a detailed view of the inspection window 502. In FIG. 8A, housing inspection window 502, syringe tube inspection window 902 and syringe lock inspection window 602 are aligned and the medicament 1006 in the syringe 1000 is visible. Furthermore, the skin sensor driver 800 is visible through the housing inspection window 502 and the syringe lock inspection window 602. In FIG. 8B, it is seen that the inspection windows are not aligned and that only a part of the syringe lock 600 is visible behind the housing inspection window indicating that the device is not ready for delivering an injection dose.
[0168] Thus, a user or patient is able to see the medicament through the inspection windows 502, 602 and 902 at the time of injection of the medicament, as it gives the user a sense of what is injected.
[0169] In FIGS. 9A-D, a reloading mechanism is shown in more detail. In FIG. 9A, the syringe 1000 with needle 1002 is seen projecting from syringe tube 900 in a first end, such as a forward end, 904. The syringe tube 900 is engaged with plunger rod tube 1100 and tabs 1110 on the forward end 1101 of plunger rod tube 1100 engages with the syringe tube 900 to interconnect the plunger rod tube 1100 and the syringe tube 900. Typically, during assembly, the pre-filled syringe 1000 with needle 1002 will be inserted into syringe tube 900 and plunger rod tube 1100, comprising hollow plunger rod 1500 and plunger rod driver 1600, will be mounted onto the syringe 1000 and syringe tube 900 and the lips 1010 of the syringe will be locked between the syringe tube 900 and plunger rod tube 1100. A tab 1112 on the plunger rod tube 1100 is configured to interact with syringe lock 600 (see FIG. 10 for further details).
[0170] The syringe tube 900 has a syringe tube inspection window 902 configured to interact with syringe lock inspection window 602 and housing inspection window 502. Syringe tube protrusions 906 may interact with skin sensor 700 and provide an initial force which must be overcome by the user when activating the auto injector. This is a further safety feature which reduces the risk of accidental activation of the auto injector.
[0171] Reload handle 1400 is slid onto the plunger rod tube 1100 and torsion ring 1800 interconnects reload handle 1400 and plunger rod tube 1100 via torsion ring tab 1802.
[0172] In FIG. 9A, a first dose has been delivered and it is seen that torsion ring tab 1802 is provided in a first reload handle slot 1404, and the torsion ring tab 1802 has moved forwards along slot side 1406 and is positioned at the bottom of the first reload handle slot 1404.
[0173] The reload handle 1400 as well as torsion ring 1800 may be symmetric, so as to evenly distribute the force applied, and that there is thus a torsion ring tab 1802 provided symmetrically on each side of the torsion ring, each torsion ring tab 1802 interconnecting each of the first reload handle slots provided symmetrically about the reload handle slot.
[0174] In FIG. 9B, the reload handle 1400 is rotated as indicated by arrow 1401, thereby forcing the torsion ring 1800 which cannot rotate itself, along the inclined slot side 1408 via torsion ring tab 1802. In FIG. 9B, it is seen that the torsion ring tab 1802 has moved slightly along the inclined slot side 1804 after having rotated the reload handle slightly, e.g. about 30 degrees. This pulls the syringe assembly comprising the syringe 1000, syringe tube 900, plunger rod tube 1100, as well as plunger rod 1500 and plunger rod driver 1600 (not shown in FIG. 9) backwards and into the reload handle 1400 as illustrated by arrow 24.
[0175] In FIG. 9C, the reload handle 1400 is further rotated, e.g. rotated 45 degrees in total, and the torsion ring tab 1802 has moved towards the top edge 1410 of the first reload handle slot 1404 further retracting the syringe assembly 20 comprising syringe 1000, syringe tube 900, plunger rod tube 1100, as well as plunger rod 1500 and plunger rod driver 1600 (not shown in FIG. 9) backwards and further into the reload handle 1400. While rotating the reload handle 1400 the plunger rod tube tabs 1112 also rotates towards a resting ledge 606 of the syringe lock 600, as may be seen from FIG. 10.
[0176] As seen in FIG. 9D, continued rotation of the reload handle 1400 lifts the torsion ring tab 1802 together with torsion ring 1800 and syringe assembly 20 over the top edge 1410 of the first reload handle top 1400 and into second reload handle slot 1414. The torsion ring 1800 including the torsion ring tab 1802 and the syringe assembly will move forward a short distance, such as a few mm, before the syringe assembly 20, and more specifically, the plunger rod tube tabs 1112 hang on the syringe lock resting ledge 606. The auto injector 10 is then in the initial position and ready to deliver a second or further injection. In that the second reload handle slot is a slot allowing only for movement longitudinally along an axis of the auto injector, the auto injector is locked after having delivered a second dose, and the auto injector is thus not configured to deliver more than two doses. Thus, the auto injector may deliver no more than two doses. Also, alternative configurations have been.
[0177] FIGS. 10A-F show a detailed view of the syringe lock guiding trail 604 enabling the skin sensor 700 to rotate the syringe lock 600 and control the dosing mechanism. Initially, as seen in FIG. 10A, the spring loaded syringe assembly 20 rests on a syringe lock resting ledge 606 in the syringe lock 600 by plunger rod tube tabs 1112, restricting forward movement of the syringe assembly 20. The skin sensor 700 is in the unlocked forward position.
[0178] In FIG. 10B, the skin sensor is pressed against the skin of a patient, and the syringe lock is rotated as indicated by arrow 24. Hereby, the syringe assembly 20 is lifted free of the syringe lock resting ledge 606.
[0179] In FIG. 10C, the syringe assembly 20 has moved downwards along syringe lock guiding trail 604, pushing the syringe assembly 20 forwards causing injection of needle 1002. During injection of the needle 1002, the syringe lock 600 is further rotated to align dosing clips with dosing windows to allow for injection of a medicament. After injection, as seen in FIG. 10D, and as the needle 1002 is retracted from the skin of a patient, the skin sensor 700 is pushed forward by skin sensor driver 800. At this point, the two clips of the skin sensor are resting on a shelf on the syringe lock, locking them in position to protect the needle. In FIG. 10E, the device is reloaded and the syringe assembly 20 is in the initial position and the skin sensor 700 in the forward unlocked position in FIG. 10F.
[0180] A friction ring may be encircling the front end 614 of the syringe lock 600. In the figures, the friction ring is not shown as a separate item, but should be understood as fitting around the small recess shown at the front end 614 of the syringe lock 600 The friction ring is for reduce friction between the syringe lock 600 and the housing 500 when the syringe lock 600 is rotated in connecting with reloading of the device. The friction ring may be fully clipped to syringe lock so that it does not move relative to syringe lock 600.
[0181] In FIGS. 11A-B, a reload handle 1400 is shown having a reload handle slot 1414 having a straight side for the injection process and an inclined side 1416 which the torsion ring tab 1802 follows upon reloading. It is seen that the reload handle is provided with only two symmetric reload handle slots 1414, and that therefore an infinite number of reloads is possible as the rotation of the handle is never locked. This reload handle allows for re-fitting with for example a new syringe assembly. The number of reload slots is primarily limited by the size of the auto injector. The difference between FIGS. 11A and 11B is the rotation of the re-load handle 1400 in relation to the torsion ring 1800 and the plunger rod tube 1100.
[0182] In FIG. 12, a syringe assembly 20 is shown comprising syringe tube 900, syringe 1000 with a rigid needle shield, plunger rod tube 1100, hollow plunger rod 1500, plunger rod driver 1600 and plunger rod driver guide 950. It is envisaged that the parts may be assembled using various connector parts, and furthermore, the plunger rod tube 1100 and syringe tube 900 may be provided as one part. It is seen that the syringe assembly 20 may be moved as one element and either be pushed forward by a syringe driver (1200 not shown in FIG. 12) acting on syringe tube flange 906 and/or plunger rod flange 1114 or retracted by a reload handle action acting on the syringe assembly 20, such as on the syringe assembly tab 1112.
[0183] FIG. 13 shows a cross-sectional view of the protective casing 100 comprising the first casing recess 102. The casing recess 102 is a small protrusion inside the casing 100, which is configured for interacting with the one or more recap prevention springs 400 shown in FIGS. 14B-C if a user tries to push the protective casing 100 onto the auto injector again after removal of the casing 100. This ensures that the second (or subsequent) dose of medication is not by mistake pushed out of the auto injector due to a user trying the push the casing 100 on to the auto injector again.
[0184] The recap prevention cap 300 and two recap prevention springs 400 are shown in FIG. 14A, and FIGS. 14B-C, respectively. The recap prevention cap 300 comprises two openings 302 through which each of the two recap prevention springs 400 protrudes. The one or more recap prevention springs 400 are preferably made from a bio-compatible metal material. Examples of such are titan or stainless steel.
[0185] The recap prevention cap 300 shown in FIG. 13 comprises a front end 304 and a rear end 306 where in between is found two protruding portions 302. The protruding portions 302 are positioned in front of the recap prevention spring 400. When the protective casing 100 is removed from the auto injector, the recap prevention springs 400 push the protruding portions 302 outwardly as indicated with the arrows 308 in FIG. 15. This makes the protruding portions 302 extend outwardly such that the protrusions 302 interact with the casing recess 102 whereby the casing is prevented from being pushed fully onto the auto injector after use.
[0186] In FIG. 15, the position of the recap prevention cap 300 and the recap prevention springs can be seen in the view of the lower part of the auto injector.
[0187] As shown in FIG. 14C, the recap prevention springs 400 will normally have two bending portions 402, 404 allowing the springs 400 to fit behind the recap prevention cap.
[0188] The recap prevention springs 400 are shown as separate springs in FIGS. 14B-C, but may also be connected in a ring-shaped configuration.
REFERENCES
[0189] 10 auto injector [0190] 20 syringe assembly [0191] 100 casing/protective cap [0192] 102 first casing recess [0193] 200 rigid needle shield (RNS) remover [0194] 300 recap prevention cap [0195] 302 protruding portions in the recap prevention cap [0196] 304 front end of the recap prevention cap [0197] 306 rear end of the recap prevention cap [0198] 400 recap prevention spring [0199] 402 bending portion [0200] 404 bending portion [0201] 500 housing [0202] 502 indicator window [0203] 504 indicator window [0204] 506 front end of the housing [0205] 600 syringe lock [0206] 602 syringe lock inspection window [0207] 604 syringe lock guide slot/trail [0208] 606 syringe lock ledge [0209] 608 a release position [0210] 610 syringe lock end stop [0211] 612 syringe lock angled surface [0212] 614 front end of the syringe lock [0213] 700 skin sensor [0214] 702 skin sensor opening [0215] 704 protrusion [0216] 706 skin sensor angled surface [0217] 708 skin sensor lock tabs [0218] 800 skin sensor spring/skin sensor driver [0219] 900 tube syringe [0220] 906 syringe tube flange [0221] 950 rigid needle shield [0222] 1000 syringe with needle [0223] 1002 needle [0224] 1004 syringe stopper [0225] 1006 syringe content/medicament [0226] 1008 syringe flange [0227] 1100 plunger rod tube [0228] 1108 deflectable locking members/first stop [0229] 1110 deflectable locking members/second stopper [0230] 1114 plunger rod flange [0231] 1200 insertion spring/syringe driver [0232] 1300 lock ring housing [0233] 1400 handle [0234] 1402 tapered knob [0235] 1420 opening [0236] 1422 opening [0237] 1500 hollow plunger rod [0238] 1504 distal end of the plunger rod [0239] 1506 forward end of the plunger rod [0240] 1508 plunger rod stop/protrusion [0241] 1510 forward end of the plunger stop rod [0242] 1600 injection spring/plunger rod driver [0243] 1602 one end of the plunger rod driver [0244] 1700 pin for injection spring/plunger rod driver guide [0245] 1800 torsion ring [0246] 1900 handle top [0247] 2000 patient's skin
