A signalling module for a medicament delivery device

Abstract

The present invention relates to a signalling module (100) for a medicament delivery device (10), the medicament delivery device comprising a power pack (42), in turn comprising a drive spring (44) operably connected to a plunger rod (46), the plunger rod arranged to, when the power pack is activated, act on a syringe (36) for delivering a dose of medicament, the signalling module (100) comprising: a signalling element (102; 110) comprising at least one biased force element (106; 114) operably connected to said plunger rod; an impact surface (44; 56); the signalling element (102; 110) being held in a tensioned state by the plunger rod (46) in an initial state, wherein, when the power pack (42) is activated, causes a linear movement of the plunger rod (46) in a proximal direction, thereby releasing the signalling element (102; 110) at a position close to end of dose delivery, wherein said signalling element hits said impact surface (44; 56) and causes an indication to a user that a dose of medicament has been delivered.

Description

[0001] A SIGNALLING MODULE FOR A MEDICAMENT DELIVERY DEVICE

[0002] TECHNICAL AREA

[0003] The present invention relates to a signaling module for a medicament delivery device such as an auto-injector.

[0004] BACKGROUND OF INVENTION

[0005] Medicament delivery devices have been on the market for many years for selfadministration of drugs. Many of these are designed as auto-injectors with the aim that the end-user should be required to perform as few steps as possible in order to initiate an injection. In order to provide the user with information regarding for instance the injection sequence and in particular when the injection sequence has ended, wherein the medicament has been delivered to the user, and that it is safe to remove the medicament delivery device, signalling elements have been developed that provide audible and / or tactile signals at the end of the injection sequence.

[0006] EP 2 485 786 discloses an auto-injector with an information means that provides information when an injection sequence is completed. The information means comprises an activator member that is held in a tensioned state by a plunger rod and its drive spring. When the plunger rod has moved near its end stroke, the activator member is released and is moved distally by the remaining force from the drive spring, wherein the activator strikes an end wall of the device, providing an audible signal.

[0007] WO 2015 / 185311 discloses an auto-injector having a power pack with a plunger rod driver in tensioned state by a drive spring. When the device is activated, the plunger rod driver drives the plunger rod to inject a dose of medicament. A signal generating element is releasably connected to the proximal end of the plunger rod driver and moves together with the plunger rod driver during the injection. At the end of the injection sequence, the signal generating element is disconnected from the plunger rod driver, whereby the latter is forced rapidly in the proximal direction by the drive spring and hitting a surface of the signal generating element. This impact causes an audible and / or tactile signal that the medicament has been delivered. Even though many of these devices on the market have adequate functionality regarding end of injection information, there is always room for improvements.

[0008] BRIEF DESCRIPTION OF INVENTION

[0009] The aim of the present invention is to provide a signalling module for a medicament delivery device with a high degree of robustness and reliable functionality.

[0010] This aim is obtained with a medicament delivery device according to the features of the independent patent claim. Preferable embodiments of the invention form the subject of the dependent patent claims.

[0011] According to a main aspect, a signalling module for a medicament delivery device is provided, where the medicament delivery device comprises a power pack, in turn comprising a drive spring operably connected to a plunger rod, the plunger rod being arranged to, when the power pack is activated, act on a syringe for delivering a dose of medicament.

[0012] The signalling module comprises a signalling element comprising at least one biased force element operably connected to said plunger rod, an impact surface, the signalling element being held in a tensioned state by the plunger rod in an initial state, wherein, when the power pack is activated, causes a linear movement of the plunger rod in a proximal direction, thereby releasing the signalling element at a position close to end of dose delivery, wherein said signalling element hits said impact surface and causes an indication to a user that a dose of medicament has been delivered.

[0013] With this solution, the signalling element is directly connected to the plunger rod and is held by the plunger rod in the tensioned state. This provides a direct action by the signalling element when the plunger rod is moved as well as a solution with few components, although providing a positive and reliable feedback to the user that a dose has been delivered.

[0014] According to an aspect, the signalling element may comprise two force elements in the form of two arms interconnected and biased apart in a non-tensioned state. In this regard, the arms may be forced together and arranged in a space of the plunger rod. Thus, the tension or force is built-in in the signalling element, thereby requiring very few components.

[0015] According to a further aspect, the signalling element may be held stationary in relation to the plunger rod and when the plunger rod approaches the end of dose delivery position, the arms of the signalling element are moved out of contact with the space of the plunger rod, and due to the tension built-up in the arms, they will move rapidly and hit the impact surface.

[0016] According to one embodiment, the space of the plunger rod may comprise an elongated recess in which the arms fit in the tensioned state.

[0017] As an alternative embodiment, the space of the plunger rod may comprise two opposite grooves forming two distally directed tongues, and wherein each of the arms of the signalling element further comprises a transversal end portion that in the tensioned state rests on a respective side surface of the tongues. In this regard, the arms of the signalling element may be crossed in the tensioned state, which will increase the built-in force of the signalling element.

[0018] These and other aspects of, and advantages with, the present invention will become apparent from the following detailed description of the invention and from the accompanying drawings.

[0019] BRIEF DESCRIPTION OF DRAWINGS

[0020] In the following detailed description of the invention, reference will be made to the accompanying drawings, of which

[0021] Fig. 1 is a perspective view of an embodiment of a medicament delivery device according to the invention,

[0022] Figs. 2-3 are cross-sectional views of the device of Fig. 1 , Fig. 4 is a detailed view of a signalling module comprised in the device of Fig. 1 and interacting component of the device,

[0023] Figs. 5-6 are functional views of the signalling module of Fig. 4,

[0024] Figs. 7-8 are detailed views of an alternative signalling module comprised in the device of Fig. 1 and interacting components, and

[0025] Figs. 9-10 are functional views of the signalling module of Figs. 7-8.

[0026] DETAILED DESCRIPTION OF THE INVENTION

[0027] In the detailed description, the word longitudinal will be used, defining directions coinciding with an axis L as shown in Fig. 1 . The word transversal or radial will be used, defining directions generally perpendicular to the axis L. Further the word proximal will be used, P in Fig. 1 , defining the part or end or direction of / or the device that is pressed against a dose delivery site of a patient or user. The word distal will also be used, D in Fig. 1 , defining the part or end or direction of / or the device that is opposite to proximal.

[0028] The signalling module according to the invention may be used in several different types of medicament delivery devices provided with different features and functionalities. For the sake of understanding, the signalling module will now be described in connection with an exemplary medical delivery device. The exemplary medicament device 10 shown in the drawings comprises a generally elongated, tubular body 12, Fig. 1 . A generally tubular end cap should further be provided but is omitted in the drawings for the sake of clarity.

[0029] The device 10 is further provided with a generally tubular needle cover 22, Figs. 1 and 3. The proximal end of the needle cover 22 is provided with an end wall 24 having a central opening 26. The needle cover 22 is preferably provided with distally directed activating elements 28, Fig. 2.

[0030] The needle cover 22 is arranged outside a generally tubular syringe holder 30, Fig. 2. The syringe holder 30 is fixated to the body 12 by suitable means. The syringe holder 30 may further be arranged with an outwardly directed circumferential ledge 32 at its proximal end. The proximally directed surface of the ledge 32 is provided with a seat in which a distal end of a helical needle cover spring 34 fits. The proximal end of the needle cover spring 34 will be in contact with an inner surface of the end wall 24 of the needle cover 22.

[0031] Inside the syringe holder 30 a syringe 36 can be fitted, Fig. 3. The syringe 36 is provided with an injection needle 38 at its proximal end. The needle 38 is protected and kept sterile by a needle shield (not shown). The syringe 36 is filled with medicament which is contained there by a resilient stopper 40.

[0032] Distally of the syringe holder 30 a power pack 42 is arranged, Fig. 2. The power pack 42 is provided with a compression or drive spring 44, Figs. 2 and 3. Further, inside the drive spring 44, an elongated tubular plunger rod 46 is provided, Figs 2, 3. The proximal end of the plunger rod 46 is arranged with a distally directed ledge 48 on which the proximal end of the drive spring 44 rests. The distal end of the plunger rod 46 may be provided with a recess 50. In the recess 50, ledges 52 of a locking element 54 is arranged for holding the plunger rod 46 in a tensioned state by the drive spring 44. Fig. 3. A generally tubular spring housing 56 is further provided outside the drive spring, the spring housing 56 is provided with an annular ledge 58. In the initial state of the device, the locking element 54 rests against the annular ledge 58 of the spring housing 56 and holds the plunger rod 46 with the drive spring 44 tensioned as seen in Fig. 2. The power pack 42 is operably connected to the needle cover 22 via the activating elements 28. The device is further provided with an end hat 60 attached to the distal end of the body, Fig. 2.

[0033] According to the invention, the device is provided with a signalling module 100 that in the first embodiment comprises a signalling element 102. According to Figs. 4-6, the signalling element 102 comprises a metal wire having a distal end loop 104 and two force elements in the form of arms 106 provided with an inherent bias force. Fig. 4 shows the signalling element 102 in a non-tensioned state with the arms 106 inclined in relation to each other. The arms 106 are pressed together and placed in an interior cavity 62 of the plunger rod 50, Fig. 5, wherein the arms 106 of the signalling element 102 are forcibly biased together in the cavity 62 of the plunger rod 46. The distal end loop of the signalling element 102 is positioned in the device against suitable stop ledges 63 preventing the force element to move in the proximal direction.

[0034] The device is intended to function as follows. When the device is to be used, an end cap (not shown) may be removed by pulling it off from the body. A user then presses the proximal end of the device, i.e. the needle cover 22 that is protruding out of the body 12 as seen in Fig. 1 , against a dose delivery site. This causes the needle cover 22 to move into the body 12 of the device, wherein a penetration of the needle is performed on the dose delivery site. The movement of the needle cover 22 causes its activation elements 28 to activate the activation mechanism such that the ledges 52 of the locking element 54 are moved out of engagement with the recess 50 of the plunger rod 46, Fig. 6.

[0035] The plunger rod 46 is now released and due to the force of the drive spring 44, the plunger rod 46 is moved proximally and acting on the stopper 40 of the syringe 36, whereby an injection is performed in that the stopper 40 is moved proximally in the syringe 36 and expels medicament through the injection needle 38, Fig. 6.

[0036] When the plunger rod 46 has moved a distance wherein the syringe 36 is about to be emptied, the two force elements, arms 106 of the signalling element 102 are moved out of the interior cavity 62 of the plunger rod, Fig. 6, and by the biasing force of the arms 106, they will hit an impact surface comprised in the signalling module, which in the embodiment shown is inner surfaces of the drive spring 44, creating an audible and / or tactile end of dose signal. However, the impact surface of the signalling module could be an inner wall of the housing of the device or another component of the device, thereby creating an audible and / or tactile end of dose signal.

[0037] When the injection is completed, the device is removed from the injection site. The needle cover 22 is free to move and will be pushed in the proximal direction by the needle cover spring 34. The proximal movement of the needle cover 22 will cause a lock-out mechanism (not shown) to engage with the needle cover 22 in the extended position, thereby locking the needle cover 22 in this extended position covering the needle 38. The device can now be discarded. An alternative solution to a signalling module 100 is shown in the figures 7-9. In this embodiment, the signalling element 110 of the signalling module 100 comprises an end loop 112 of metal wire wound with two coils and is also provided with two proximally extending force elements in the form of arms 114 that are provided with an inherent biasing force. Fig. 7 shows the signalling element 110 in a non-tensioned state with the arms 114 inclined in relation to each other. Further, the free ends of the arms 114 are provided with transversally extending end portions 116. Moreover, the plunger rod is provided with two oppositely positioned longitudinal elongated slots or grooves 64, creating two distally extending tongues 66. When assembled, the signalling element 110 is pressed together so that the arms 114 are crossed and positioned in the grooves 64 of the plunger rod 46 wherein each of the transversal end portions 116 rest on a respective side surface of the tongues 66, Fig. 8. Thus, the signalling element 110 is held in a tensioned state by the end portions being retained by each tongue 66 with the arms crossed, Fig. 9.

[0038] Thus, as the device is activated and the plunger rod 46 is moving in the proximal direction as described above, the end portions 116 move along the tongues 66 of the plunger rod 46 until the distal end of the plunger rod 46 passes or leaves the end portions 116 near or at the end of injection. This will cause the biased arms 114 to move rapidly outwards leaving the crossed position and hitting an impact surface of the signalling module as mentioned above, Fig. 10, in this embodiment a part of the spring housing 56, thereby causing an audible and / or tactile indication of the end of the injection sequence.

[0039] Even though the signalling element of the second embodiment is described having a number of coils, it could of course have an end shape more in line with the first embodiment, but with the arms crossed. In this regard, the tensioned force of both embodiments may be chosen and adjusted by the choice of metal material, thickness of the wire, length of the arms, etc, depending on the desired size of the feedback.

[0040] As mentioned above, the signalling module 100 according to the invention may be used in many different types of medicament delivery devices requiring an end of medicament delivery indication and thereby it is to be understood that it is not limited to the above described exemplary device, merely providing a context where the present invention may be utilized.

[0041] It is to be understood that the embodiment described above and shown in the drawings is to be regarded only as a non-limiting example of the invention and that it may be modified in many ways within the scope of the patent claims.

Claims

PATENT CLAIMS1 . A signalling module (100) for a medicament delivery device (10), the medicament delivery device comprising a power pack (42), in turn comprising a drive spring (44) operably connected to a plunger rod (46), the plunger rod arranged to, when the power pack is activated, act on a syringe (36) for delivering a dose of medicament, the signalling module (100) comprising: a signalling element (102; 110) comprising at least one biased force element (106; 114) operably connected to said plunger rod; an impact surface (44; 56); the signalling element (102; 110) being held in a tensioned state by the plunger rod (46) in an initial state, wherein, when the power pack (42) is activated, causes a linear movement of the plunger rod (46) in a proximal direction, thereby releasing the signalling element (102; 110) at a position close to end of dose delivery, wherein said signalling element hits said impact surface (44; 56) and causes an indication to a user that a dose of medicament has been delivered.

2. A signalling module according to claim 1 , wherein the signalling element (102; 110) comprises two force elements (106; 1 14 in the form of two arms interconnected and biased apart in a non-tensioned state.

3. A signalling module according to claim 2, wherein the arms (106, 114) are forced together and arranged in a space (62; 64)of the plunger rod (46).

4. A signalling module according to claim 4, wherein the signalling element (102; 110) is held stationary in relation to the plunger rod (46) and when the plunger rod (46) approaches the end of dose delivery position, the arms (106; 114) of the signalling element (102; 110) are moved out of contact with the space (62; 64) of the plunger rod (46),and due to the tension built-up in the arms (106, 114), they will move rapidly and hit the impact surface (44; 56).

5. A signalling module according to claim 3 or 4, wherein the space of the plunger rod comprises an elongated recess (62) in which the arms(106) fit in the tensioned state.

6. A signalling module according to claim 3 or 4, wherein the space of the plunger rod comprises two opposite grooves (64) forming two distally directed tongues (66), and wherein each of the arms (114) of the signalling element further comprises a transversal end portion (116) that in the tensioned state rests on a respective side surface of the tongues (66).

7. A signalling module according to claim 6, wherein the arms (114) of the signalling element (110) are crossed in the tensioned state.

Images