GB2504128A - Automatic injector with a skin contact element - Google Patents

Automatic injector with a skin contact element Download PDF

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Publication number
GB2504128A
GB2504128A GB201212915A GB201212915A GB2504128A GB 2504128 A GB2504128 A GB 2504128A GB 201212915 A GB201212915 A GB 201212915A GB 201212915 A GB201212915 A GB 201212915A GB 2504128 A GB2504128 A GB 2504128A
Authority
GB
United Kingdom
Prior art keywords
movable assembly
housing
skin contact
contact element
needle
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB201212915A
Other versions
GB201212915D0 (en
Inventor
Matthew Young
Ralph George Lamble
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Oval Medical Technologies Ltd
Original Assignee
Oval Medical Technologies Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Oval Medical Technologies Ltd filed Critical Oval Medical Technologies Ltd
Priority to GB201212915A priority Critical patent/GB2504128A/en
Publication of GB201212915D0 publication Critical patent/GB201212915D0/en
Publication of GB2504128A publication Critical patent/GB2504128A/en
Withdrawn legal-status Critical Current

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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/178—Syringes
    • A61M5/20—Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically
    • A61M5/2033—Spring-loaded one-shot injectors with or without automatic needle insertion
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/178—Syringes
    • A61M5/31—Details
    • A61M5/32—Needles; Details of needles pertaining to their connection with syringe or hub; Accessories for bringing the needle into, or holding the needle on, the body; Devices for protection of needles
    • A61M5/3205—Apparatus for removing or disposing of used needles or syringes, e.g. containers; Means for protection against accidental injuries from used needles
    • A61M5/321—Means for protection against accidental injuries by used needles
    • A61M5/3243—Means for protection against accidental injuries by used needles being axially-extensible, e.g. protective sleeves coaxially slidable on the syringe barrel
    • A61M5/326—Fully automatic sleeve extension, i.e. in which triggering of the sleeve does not require a deliberate action by the user
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/178—Syringes
    • A61M5/20—Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically
    • A61M2005/206—With automatic needle insertion
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/178—Syringes
    • A61M5/31—Details
    • A61M2005/3117—Means preventing contamination of the medicament compartment of a syringe
    • A61M2005/3121—Means preventing contamination of the medicament compartment of a syringe via the proximal end of a syringe, i.e. syringe end opposite to needle cannula mounting end
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/178—Syringes
    • A61M5/31—Details
    • A61M5/32—Needles; Details of needles pertaining to their connection with syringe or hub; Accessories for bringing the needle into, or holding the needle on, the body; Devices for protection of needles
    • A61M5/3205—Apparatus for removing or disposing of used needles or syringes, e.g. containers; Means for protection against accidental injuries from used needles
    • A61M5/321—Means for protection against accidental injuries by used needles
    • A61M5/3243—Means for protection against accidental injuries by used needles being axially-extensible, e.g. protective sleeves coaxially slidable on the syringe barrel
    • A61M5/326—Fully automatic sleeve extension, i.e. in which triggering of the sleeve does not require a deliberate action by the user
    • A61M2005/3267—Biased sleeves where the needle is uncovered by insertion of the needle into a patient's body
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M2205/00—General characteristics of the apparatus
    • A61M2205/58—Means for facilitating use, e.g. by people with impaired vision
    • A61M2205/582—Means for facilitating use, e.g. by people with impaired vision by tactile feedback
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/178—Syringes
    • A61M5/24—Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic
    • A61M5/2455—Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic with sealing means to be broken or opened
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/178—Syringes
    • A61M5/31—Details
    • A61M5/32—Needles; Details of needles pertaining to their connection with syringe or hub; Accessories for bringing the needle into, or holding the needle on, the body; Devices for protection of needles
    • A61M5/3202—Devices for protection of the needle before use, e.g. caps
    • A61M5/3204—Needle cap remover, i.e. devices to dislodge protection cover from needle or needle hub, e.g. deshielding devices

Abstract

An automatic injector device comprises a housing 24, 26 and a movable drive assembly including a needle. The movable assembly is positioned within the housing 24, 26 in an initial position. A stored energy source, such as a spring, 32, 34 is located within the housing 24, 26 and, in operation, is configured to drive the movable assembly from the initial position through the housing 24, 26 to an insertion position. A skin contact element 18 is coupled to the housing 24, 26 and configured to contact an injection site in operation. A force transfer mechanism (Fig. 4 19, 40) is configured to transfer force from the movable assembly to the skin contact element 18 when the movable assembly is at or near to the insertion position. Preferably the movable assembly comprises a drug container 10, a drive member 28, 30 positioned between the stored energy source 32, 34 and the drug container 10, a cradle 38 to hold the drug container, and a needle hub. Preferably the force transfer mechanism comprises a portion of the movable assembly and a resilient element.

Description

AUTOMATIC INJECTION DEVICE
Field of the Invention
The present invention relates to automatic injection devices; such as autoinjectors, that S provide for automatic needle insertion, and in particular to a mechanism for indicating to a user that a needle insertion operation has successfully been completed.
Background to the Invention
An autoinjector is a drug delivery device which contains a medical, therapeutic, diagnostic, pharmaceutical or cosmetic compound (drug) before it is administered, and which is used to administer the compound through the skin of the patient via a hollow needle.
Autoinjectors may be used by the patient themselves or by a different user, and are also used to administer drugs to animals.
Autoinjectors are typically used because they reduce the amount of training and effort needed by a user compared with that needed for a syringe, by automating either or both of the processes of inserting the needle into the patient and expelling the drug through the needle. They can also reduce the fear of injection by hiding the needle from the patient.
Autoinjectors typically include a housing containing a drug and a plunger that is driven by an automatic mechanism to move the plunger within the housing to eject the drug through a hypodermic needle. The automatic mechanism may also move the needle relative to the housing to insert the needle into a patient. Motive power for the mechanism may come from a stored energy source or sources, such as one or more metal springs or compressed gas.
It may be that the only indication that the user gets to indicate that the needle has been inserted is any pain that they feel as a result. However, with a very thin needle the user may experience little or no pain. This is of course desirable and efforts continue to be made to reduce pain further. Furthermore, pain is not an indication that the needle has been fully inserted to the desired depth and that the device is functioning properly.
It is an object of the present invention to provide an indication to users of automatic injection devices that needle insertion has been successfully completed.
Summary of the Invention
Aspects of the present invention are defined in the appended independent claims, to which reference should be made. Preferred features of the invention are defined in the dependent claims.
In a first aspect of the invention there is provided an automatic injector device comprising: a housing; a movable assembly including a needle, the movable assembly positioned within the housing in an initial position; a stored energy source within the housing, in operation the stored energy source configured to drive the movable assembly from the initial position through the housing to an ---insertion position; a skin contact element coupled to the housing and configured to contact an injection site on a patient in operation; and a force transfer mechanism configured to transfer force from the movable assembly to the skin contact element when the movable assembly is at or near to the insertion position.
The movable assembly may comprise a drug container coupled to the needle. The needle may be permanently fixed to the drug container and in contact with the drug prior to use of the device. Alternatively the needle may be fixed to a needle hub separate to the drug container, and the drug container and needle hub may then be moved relative to one another during operation of the device, either before or after insertion of the needle into a patient, to bring the needle into fluid communication with the drug. The movable assembly may also comprise a drive member positioned between the stored energy source and the drug container, the drive member pushing the drug container and needle to the insertion position. The movable assembly may also include a cradle configured to hold the drug container. The cradle may comprise mechanical features that form part of automatic mechanisms within the device. The cradle may be fixed to the drug container. The device may be a reloadable device with the cradle configured to receive new drug containers during a reloading operation.
The force transfer mechanism may comprise a portion of the movable assembly and a resilient element coupled to or integral with the skin contact element, wherein the portion of the movable assembly contacts the resilient element coupled to or integral with the skin contact element when the movable assembly is at or near to the insertion position.
In one embodiment the resilient element comprises a spring positioned between the skin contact element and the housing and configured to bias the skin contact element away from the housing. A biasing spring of this type is typically provided to urge the skin contact element into a position covering the needle after the device has been used-This reduces the likelihood of needle stick injury following use. In this embodiment the portion of the movable assembly contacts and compresses the spring which in turn transfers a small force to the skin contact element, which is in contact with the injection site. The user thus experiences a small shock when the movable assembly is at or near to the insertion position. The insertion position typically corresponds to the position at which the needle is fully inserted into the patient to the intended depth.
In other embodiments the resilient element may comprise one or more flexible arms on the skin contact element The one or more flexible arms may be integral components of a moulded or machined skin contact element or may be formed separately to a main body of the skin contact element and subsequently fixed to the main body. The flexible arms may extend towards the movable assembly in a direction substantially parallel to the direction of travel of the movable assembly from the initial position to the insertion position. The flexible arms may then deflect in a direction orthogonal to the direction of travel of the movable assembly from the initial position to the insertion position when they engage with the portion of the movable assembly. Alternatively the flexible arms may extend in a direction non-parallel with the direction of travel of the movable assembly from the initial position to the insertion position. The flexible arms may then deflect in a direction parallel to the direction of travel of the movable assembly from the initial position to the insertion position when they engage with the portion of the movable assembly.
The energy required to deflect the flexible arms or to compress the biasing spring is removed from the movable assembly, so the flexible arms or biasing spring act to slow the movable assembly down at or near to the point when the movable assembly reaches the insertion positiOn..
The portion of the movable assembly may comprise one or more flexible arms that deflect on contact with the resilient element on the skin contact element. This may allow even greater control of the shock or haptic feedback delivered to the user.
The portion of the movable assembly may be positioned on any component of the movable assembly, such as a needle hub, a drug container, a drive member or a cradle for receiving a drug container.
In other embodiments, the resilient element is positioned on the movable assembly rather than on the skin contact element. The force transfer mechanism then comprises a resilient element on the movable assembly and a portion of the skin contact element. The resilient element on the movable assembly contacts the portion of the skin contact element when the movable assembly is at or near to the insertion position.
The resilient element may be positioned on any component of the movable assembly, such as a needle hub, a drug container, a drive member or a cradle for receiving a drug container. The resilient element may be an integral part of that component or separately formed and subsequently fixed to that component.
The resilient element may comprise one or more flexible arms on the movable assembly.
The flexible arms may extend towards the skin contact element in a direction substantially parallel to the direction of travel of the movable assembly from the initial position to the insertion position. The flexible arms may then deflect in a direction orthogonal to the direction of travel of the movable assembly from the initial position to the insertion position when they engage with the portion of the movable assembly. Alternatively the flexible arms may extend in a direction non-parallel with the direction of travel of the movable assembly from the initial position to the insertion position. The flexible arms may then deflect in a direction parallel to the direction of travel of the movable assembly from the initial position to the insertion position when they engage with the portion of the skin contact element. In these embodiments, the portion of the skin contact element may also comprise one or more resilient elements.
The device may further comprise a means to drive the skin contact element to an extended position in which the skin contact element surrounds the needle when the movable assembly is in the insertion position. The means to drive the skin contact element may be a biasing spring positioned between the skin contact element and the housing.
The skin contact element may be configured to move from an initial position towards or into the housing to an activation position to activate the device, wherein the skin contact element is locked in the activation position against the action of the drive means by a locking assembly, and the force transfer mechanism may be configured to release the locking assembly when the movable assembly is at or near to the insertion position. For example, a component of the movable assembly may engage a lacking member on the skin contact element and push it out of engagement with a corresponding locking member on the housing when the movable assembly is at or near to the insertion position.
In a second aspect of the invention, there is provided a method of providing an indication of a needle insertion operation to a user of an automatic injection device, the device comprising a housing, a movable assembly including a needle, the movable assembly positioned within the housing in an initial position, a stored energy source within the housing, in operation the stored energy source configured to drive the movable assembly from the initial position through the housing to an insertion position, and a skin contact element coupled to the housing and configured to contact an injection site in operation, the method comprising: transferring force from the movable assembly to the skin contact element when the movable assembly is at or near to the insertion position.
Brief Description of the Drawings
Embodiments of the invention will now be described in detail, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a cross-sectional view of an autoinjector suitable for incorporating a mechanism in accordance with the invention.
Figure 2 is a cross-sectional view of an autoinjector in accordance with a first embodiment of the invention; Figure 3 is a perspective view of the cradle component of Figure 2, in isolation; Figure 4 is a detail cross-sectional view of the front end of the autoinjector of Figure 2; Figure 5 is a cross-sectional view of the front end of the autoinjector of Figure 2 with the cap removed, prior to activation; Figure 6 is a cross-sectional view of the front end of the autoinjector of Figure 2 with the skin contact element retracted to an activation position; Figure 7 is a cross-sectional view of the front end of the autoinjector of Figure 2 illustrating the operation of the force transfer mechanism; Figure 8 is a cross-sectional view of the front end of the autoinjector of Figure 2 following operation with the skin contact element in an extended position; Figure 9 is a cross-sectional view of an autoinjector in accordance with a second embodiment of the invention; Figure 10 is a cross-sectional view of the front end of the autoinjector of Figure 9 illustrating the operation of the force transfer mechanism; Figure 11 is a cross-sectional view of the front end of the autoinjector of Figure 9 in the insertion position; Figure 12 is a cross-sectional view of an autoinjector in accordance with a third embodiment of the invention; Figure 13 is a perspective view of the skin contact element of Figure 12, in isolation; Figure 14 is a perspective view of a drive member of Figure 12, in isolation; Figure 15 is detailed perspective view of the force transfer mechanism of the third embodiment, with the housing removed for clarity; Figurel 6 is detailed perspective view of the force transfer mechanism of the third embodiment, with the housing removed for clarity, in the insertion position; Figure 17 is a cross-sectional view of an autoinjector in accordance with a fourth embodiment of the invention; Figure 18 is a perspective view of the skin contact element of Figure 17, in isolation; Figurel9 is a perspective view of a drive member of Figure 17, in isolation; Figure 20 is a detailed cross-sectional view of the autoinjector of Figure 17 illustrating the operation of the force transfer mechanism; Figure 21 is a detailed cross-sectional view of the autoinjector of Figure 17 illustrating the the force transfer mechanism in the insertion position; Figure 22 is a cross-sectional view of an autoinjector in accordance with a fifth embodiment of the invention; Figure 23 is a perspective view of the cradle component of Figure 22, in isolation; Figure 24 is a perspective view of the skin contact element of Figure 22, in isolation; Figure 25 is a cross-sectional view of the front end of the autoinjector of Figure 22, illustrating the engagement of the components of the force transfer mechanism; Figure 26 is a cross-sectional view of the front end of the autoinjector of Figure 22 at the completion of drug delivery; Figure 27 is a cross-sectional view of an autoinjector in accordance with a sixth embodiment of the invention; Figure 28 is a perspective view of a drive member of Figure 27, in isolation; Figure 29 is a perspective view of the skin contact element of Figure 27, in isolation; Figure 30 is a cross-sectional view of the autoinjector of Figure 27, illustrating the engagement of the components of the force transfer mechanism; and Figure 31 is a detailed view of the force transfer mechanism of Figure 27, in the insertion position.
Detailed Description
Figure 1 is a cross-sectional view of an autoinjector that includes a mechanism for automatically inserting a needle into a patient prior to delivery of a drug from the autoinjector. The autoinjector shown in Figure 1 comprises a primary drug container 10 housing a drug 12. A plunger l6is positioned within the drug container 10. A seal 11 is provided over a rear end of the drug container 10. In use, the plunger is driven through the drug container to expel the drug through a needle 14, which is fixed to the front end of the drug container 10. Prior to use, the needle is covered by a needle shield 20 which acts both to provide a seal to keep the needle sterile before use and to provide a liquid seal to prevent leakage of the drug 12 through the needle 14. The needle shield 20 is coupled to a cap 22 by latches 23 formed on the cap, so that when the cap is removed from the autoinjector housing 24, the needle shield 20 is removed at the same time.
The autoinjector has a housing 24 which includes a front end portion 26. In the embodiment shown in Figure 1, portion 24 is formed as a separate component to portion 26, but they are fixed relative to one another. The housing 24, 26 houses the drug container 10 as well as a drive mechanism which, in the example shown in Figure 1, comprises a first drive member 28 configured to drive the drug container through the housing by the action of a first drive spring 32, and a second drive member 30, configured to drive the plunger 16 through the drug container 10 by the action of a second drive spring 34. The first drive spring 32 in fact moves an assembly of components, comprising the needle, drug container, cradle element and first drive member. The drive assembly is configured such that the second drive spring 34 is only released after the first drive member 28 has completed, or nearly completed the driving of the drug container through the housing to insert the needle 14 into the patient. The second drive member 30 then breaks the seal 11, engages the plunger 16 and pushes the plunger through the drug container to eject the drug.
The drug container lOis initially restrained from moving through the housing under the action of the first drive spring 32 by latching arms 38 which are integral with the housing 24.
The latching arms 38 engage the cradle element 36 which fits around a front end of the drug container 10. The device is activated by moving a skin contact element 18, referred to in this example as an activation element but which also acts as a needle cover after use, rearwardly into the housing 24 against the action of biasing spring 19 until windows on the activation element 15 align with the latching arms 38 and allow the latching arms 38 to move outwardly into the windows, thereby allowing the drug container to move forward. An autoinjector incorporating this kind of release and drive system is described in more detail in WO 2012/073035.
Figure 2 is a cross-section through an autoinjector of the type shown in Figure 1 the cross-section being at 90 degrees to the cross-section shown in Figure 1. The autoinjector shown in Figure 2 incorporates a force transfer mechanism in accordance with a first embodiment of the invention. In the embodiment shown in Figure 2the drug container 10 is held within a cradle element 38 that includes protrusions 40 formed at its front end. The protrusions 40 are configured to engage a back end of the biasing spring 19, when the cradle element is close to the end of its travel through the housing 24. The protrusions 40 transfer force from the cradle element 38 to the spring 19, to further compress the spring.
The spring transfers force through the activation element 18 to the user.
Figure 3 is perspective view of the cradle element 38 shown in Figure 2. As can be seen in Figure 3, the protrusions 40 are formed as an integral part of the cradle 35, which is a moulded plastic component.
Figure 4 is a cross-sectional perspective view showing the position of the protrusions 40 and spring 19 relative to the other components of the autoinjector. As can be seen in Figure 4, the front end of the housing 42 is modified to include a slot 46. The protrusions 40 are accommodated in the slot 46 so that the protrusions can travel through the slot and engage the back end of the spring 19. The back end of the spring 19 is otherwise supported by the front end portion of the housing 42.
Figures 5, 6, 7 and 8 illustrate the autoinjector shown in Figure 2 at various stages during its operation.
Figure 5 is a cross-sectional view of the front end of the autoinjector, with the cap 22 and needle shield 20 removed. A user pulls or screws off the cap 22 immediately prior to use.
Figure 6 is a cross-sectional view of the front end of the autoinjector of Figure 2 showing the activation element 18 pushed back into the housing 24, compressing spring 19. In this position the drug container is released for forward movement through the housing.
Figure 7 shows the autoinjector of Figure 6, with the moving assembly of the needle, drug container, cradle element and drive member moved forward through the housing to an insertion position in which the needle is fully inserted into the patient. It can be seen in Figure 7 that at this point the protrusions 40 have contacted the back end of the spring 19, to further compress the spring 19 and deliver a small shock to the user through the activation element 18.
Figure 8 shows the front end of the autoinjector of Figure 7 following delivery of the drug and withdrawal of the autoinjector from the injection site. As shown in Figure 8, the inner drive member 30 is engaged to a rear side of the plunger 16 and, under the influence of second drive spring 34, has driven the plunger 16 through the drug container 10 to eject the drug 12 through the needle 14. Following removal of the autoinjector from the injection site, the activation element 18 has been urged away from the housing 24 by the biasing spring 19 to an extended position in which it covers the needle.
Figure 9 is a cross-sectional view of an autoinjector in accordance with a second embodiment of the invention. The second embodiment of the invention shown in Figure 9 differs from the first embodiment shown in Figure 2 in that the cradle element has a different design. In the embodiment shown in Figure 2 the cradle element 48 has a pair of flexible protrusions 50 formed on its front end. The cradle element 48 is a generally cylindrical moulded plastic component as in the first embodiment and the flexible protrusions 50 are integral with the cradle 48. The front end of the housing 52 in the embodiment shown in Figure 9 is modified as compared to the front end of the housing 26 of the first embodiment. The front end of housing 52 and the second embodiment has a longer slot 56 formed in it to allow the flexible finger 50 to travel through the slot to contact the back end of the spring 19 but thereafter to flex inwardly and continue forward travel within the slot 56.
Figure 10 is a cross-sectional view of the front end of the autoinjector shown in Figure 9, with the moving assembly of drug container, needle and cradle element shown in the position at which the flexible protrusions 50 first contact the back end of the biasing spring 19. In this position, the moving assembly is close to, but not quite, in the final insertion position.
Figure 11 illustrates the moving assembly in the insertion position. Following the contact of the flexible lingers at the back end of the spring 19, the flexible fingers 50 are pressed inwardly by the spring 19 and so, in the insertion position; the flexible protrusions are located with the back end of the spring 19. With the embodiments shown in Figures 9 to 11, the flexible fingers allow for a controlled force transfer without requiring tight manufacturing tolerances..
Figure 12 is a perspective view of a third embodiment of the present invention. In the third embodiment shown in Figure 12, force is transferred from the moving assembly of the needle, drug container, cradle and drive member by the engagement of the first drive member with the activation element or needle cover.
As shown in Figure 12, the first drive member 60 which engages the rear end of the drug container 10 includes projections 62 which extend towards the front end of the drug container, outside of the drug container 10. The projections engage with flexible arms 66 formed on the activation element 64. The configuration of activation element 64 is more clearly illustrated in Figure 13.
Figure 13 is a perspective view of the activation element shown in Figure 12 and shows the position of four flexible fingers 66 extending inwardly at the rear end of the activation element. The flexible fingers 66 engage with the projections 62 on the first drive member 60.
Figure 14 is a perspective view of the first drive member 60 illustrating the four projections 62 corresponding to the four flexible fingers 66 formed on the activation element 64. The remaining features of the embodiment shown in Figure 12 are identical to that shown in Figure 1 and so are not described in detail again.
In the embodiment shown in Figure 12, as the drug container is moved towards the insertion position, the first drive member 60 travels through the housing 24 until the projections 62 engage with the flexible fingers 66. This position is shown in a detailed view in Figure 15. In Figure 15 the housing portions 24, 26 have been removed for clarity. The projections 62 each have a tapered end providing a cam surface. As the moving assembly, including the first drive member 60, moves towards the insertion position, the flexible fingers 66 are driven over the cam surfaces of the projections 62 so that the flexible fingers 66 are flexed outwardly, allowing the projections 62 to pass. It is illustrated in Figure 16 which is a perspective view, similar to that shown in Figure 15, a few moments later. The initial engagement of the projections 62 with the flexible fingers 66 transfer force from the first drug member 60 to the activation element. As the activation element is in contact with the injection site, i.e. in contact with the skin of the patient, the patient experiences this transfer of force as a small shock.
Following the completion of the delivery of the drug, the activation element can move back past the projections 62 so that the activation element 64 can move forward to an extended position covering the needle.
Figure 17 is cross-sectional view of an autoinjector in accordance with a fourth embodiment of the invention. The embodiment shown in Figure 17 is similar to that shown in Figures 12 to 16, but in the embodiment of Figure 17, the projections 72 on the first drive member 70 are flexible and engage a rigid portion of the activation element 74. Again, the remaining features of the embodiment shown in Figure 17 are identical to the embodiment shown in Figure 1 so are not described again in detail.
Figure 18 is a perspective view of the activation element 74 shown in Figure 17. The activation element 74 includes four inward facing projections 76 formed on an interior rear end of the activation element. These projections 76 engage with flexible fingers 72 that extend from the first drive member 70. The first drive member 70 is shown more clearly in Figure 19 which is a perspective view of the first drive member in isolation. The four forwardly extending flexible fingers 72 are clearly shown. The flexible fingers 72 are integrally moulded components of the first drive member 70.
Figure 20 is a detailed view showing the point of engagement between the projections 76 and the flexible fingers 72, during travel of the drug container through the housing 24 towards the insertion position. The projections 76 include a chamfered upper surface which engages with a corresponding chamfered surface on the flexible fingers 72. The chamfered surfaces are configured so that following initial contact, as the first drive member 70 continues to move forward through the housing, the flexible fingers are deflected inwardly to move past the projections 76. This is illustrated in Figure 21 which clearly shows the flexible fingers 72 bent inwardly so that the first drive member 70 can move past the projections 76. The initial contact and deflection of the flexible fingers 72 by the projections 76 transfers force from the first drive member 72 to the activation element 74. The activation element 74 is in contact with the skin of the patient and so the patient experiences this transfer of force as a small shock, indicative of the movable assembly reaching the insertion position.
From the description of the first, second, third and fourth embodiments it should be clear that force transfer from the movable assembly, which moves through the housing to insert the needle into the patient, to the activation element or any element in contact with the skin of the patient during the injection, can be achieved using any portion of the movable assembly.
In the embodiments described so far, one portion of the force transfer mechanism is resilient or flexible while the other portion, which the first portion contacts, is rigid.
However1 it is possible for both the component of the force transfer mechanism on the movable assembly and the component of the force transfer element on the activation element or needle cover to be flexible.
Figure 22 is a cross-sectional view of the front end of an autoinjector in accordance with a fifth embodiment of the invention, in which a flexible finger 82 on a cradle element 80 engages a flexible finger 86 on the interior of the activation element 84 to provide a haptic indication of needle insertion. Figure 22 illustrates the fifth embodiment, prior to use.
Again, identical reference numerals have been used to indicate components already described with reference to previous embodiments.
Figure 23 is a perspective view of the cradle 80 incorporating flexible fingers 82, shown in Figure 22. Two flexible fingers are used in the embodiment shown in Figures 22 and 23.
However, it should be clear that any number of fingers may be used.
Figure 24 is a perspective view of the activation element 84 shown in Figure 22, showing the rearward facing flexible fingers 86 formed on the activation element. As the movable assembly, including the cradle 80, moves forwardly through the housing 24 to the insertion position, flexible fingers 82 engage flexible fingers 86 to provide haptic feedback to the user. The front portion of the housing 88 is modified to include a larger opening at its front end to allow the flexible fingers 86 on the activation element to pass through and contact the flexible fingers 82 formed on the cradle element.
Figure 25 illustrates the point of contact between flexible fingers 82 and flexible fingers 86.
Flexible fingers 82 and flexible fingers 86 have correspondingly chamfered ends so that after initial contact they and move past each other. The fingers 86 on the activation element flex inwardly and the fingers 82 on the cradle flex outwardly. This is illustrated in Figure 26.
Figure 27 illustrates a sixth embodiment of the invention. Figure 27 is a cross-sectional view of an autoinjector similar to that shown in Figure 1, including cantilever elements 92 formed on the first drive member 90. Cantilever elements 92 are configured to engage a rearward facing surface of the activation element 94 just before the needle reaches its insertion position. The drive member 90 continues to move forward to the insertion position after the initial point of contact between cantilever element 92 and rearward facing surface 96 on the activation element 94. The cantilever elements 92 then deform, as shown in Figure 31.
Figure 28 is a perspective view of the first drive member 90, in isolation. Four cantilever elements 92 are formed at the front end of the first drive member 90. The cantilever elements 92 are moulded plastic fingers that extend radially outward from the first end of the first drive member 90.
Figure 29 is a perspective view of the activation element 94 used in the sixth embodiment of the invention. Four slots 96 are formed at the rear end of the activation element 94 in positions corresponding to the four cantilever elements 92 formed on the first drive member 90.
Figure 30 illustrates the sixth embodiment at the point of contact between the cantilever elements 92 and the activation element 94. The needle is almost in its fully inserted position and the second drive member 30 has not yet been released to expel the drug from the drug container 10. Contact between the cantilever elements 92 and the activation element 94 transfers force from the first drive member to the activation element 94. The activation element 94 is in contact with the injection site and so the user experiences a small shock indicative of needle insertion nearing completion.
Figure 31 is a detailed view showing the deflection of the cantilever elements 92 as the moving assembly reaches the insertion position. Cantilever element 92 is deflected rearwardly by the activation element 94. Following completion of the drug delivery, the activation element will be released to move forwardly to cover the needle and the cantilever element 92 can then return to its original configuration.

Claims (16)

  1. Claims 1. An automatic injector device comprising: a housing; a movable assembly including a needle, the movable assembly positioned within the housing in an initial position; a stored energy source within the housing, in operation the stored energy source configured to drive the movable assembly from the initial position through the housing to an insertion position; a skin contact element coupled to the housing and configured to contact an injection site on a patient in operation; and a force transfer mechanism configured to transfer force from the movable assembly to the skin contact element when the movable assembly is at or near to the insertion position.
  2. 2. An automatic injector device according to claim 1, wherein the movable assembly comprises a drug container coupled to the needle.
  3. 3. An automatic injector device according to claim 2, wherein movable assembly comprises one or more of a drive member positioned between the stored energy source and the drug container, a cradle configured to hold the drug container and a needle hub to which the needle is fixed.
  4. 4. An automatic injector device according to any preceding claim, wherein the force transfer mechanism comprises a portion of the movable assembly and a resilient element coupled to or integral with the skin contact element, wherein the portion of the movable assembly contacts the resilient element coupled to or integral with the skin contact element when the movable assembly is at or near to the insertion position.
  5. 5. An automatic injector device according to claim 4, wherein the resilient element comprises a spring positioned between the skin contact element and the housing and configured to bias the skin contact element away from the housing.
  6. 6. An automatic injector device according to claim 4, wherein the resilient element comprises one or more flexible arms on the skin contact element.
  7. 7. An automatic injector device according to claim 4, 5 orB, wherein the portion of the movable assembly comprises one or more flexible arms.
  8. 8. An automatic injector device according to any one of claims 4 to 7 when dependent on claim 3, wherein the portion of the movable assembly is a portion of the needle hub, the drug container, the drive member or the cradle.
  9. 9. An automatic injector device according to claim 1, 2 or 3, wherein the force transfer mechanism comprises a resilient element on the movable assembly and a portion of the skin contact element, wherein the resilient element on the movable assembly contacts the portion of the skin contact element when the movable assembly is at or near to the insertion position.
  10. 10. An automatic injector device according to claim 9 wherein the resilient element comprises one or more flexible arms on the movable assembly.
  11. 11. An automatic injector device according to claim 9 or 10, when dependent on claim 3 wherein the resilient element is on the needle hub, cradle, drug container or drive member.
  12. 12. An automatic injector device according to claim 9, 10 or 11, wherein the portion of the skin contact element comprises one or more resilient elements.
  13. 13. An automatic injector device according to any preceding claim further comprising means to drive the skin contact element to a final position in which the skin contact element surrounds the needle when the movable assembly is in the insertion position.
  14. 14. An automatic injector device according to any preceding claim wherein the skin contact element is configured to move from an initial position towards the housing to an activation position to activate the device, wherein the skin contact element is locked in the activation position by a locking assembly, and wherein the force transfer mechanism is configured to release the locking assembly when the movable assembly is at or near to the insertion position.
  15. 15. A method of providing an indication of a needle insertion operation to a user of an automatic injection device, the device comprising a housing, a movable assembly including a needle, the movable assembly positioned within the housing in an initial position, a stored energy source within the housing, in operation the stored energy source configured to drive the movable assembly from the initial position through the housing to an insertion position, and a skin contact element coupled to the housing and configured to contact an injection site in operation, the method comprising: transferring force from the movable assembly to the skin contact element when the movable assembly is at or near to the insertion position.
  16. 16. An automatic injector device substantially as described herein with reference to any one of the accompanying drawings.
GB201212915A 2012-07-20 2012-07-20 Automatic injector with a skin contact element Withdrawn GB2504128A (en)

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Application Number Priority Date Filing Date Title
GB201212915A GB2504128A (en) 2012-07-20 2012-07-20 Automatic injector with a skin contact element

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Application Number Priority Date Filing Date Title
GB201212915A GB2504128A (en) 2012-07-20 2012-07-20 Automatic injector with a skin contact element

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GB201212915D0 GB201212915D0 (en) 2012-09-05
GB2504128A true GB2504128A (en) 2014-01-22

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003068290A2 (en) * 2002-02-11 2003-08-21 Antares Pharma, Inc. Intradermal injector
GB2463093A (en) * 2008-04-15 2010-03-03 Medical House Plc Autoinjector with manual trigger to retract the needle
WO2010053574A1 (en) * 2008-11-07 2010-05-14 Becton, Dickinson And Company Pen needle assembly for intradermal medication injection
WO2012073035A1 (en) * 2010-12-02 2012-06-07 Oval Medical Technologies Limited Delivery mechanism for an autoinjector

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003068290A2 (en) * 2002-02-11 2003-08-21 Antares Pharma, Inc. Intradermal injector
GB2463093A (en) * 2008-04-15 2010-03-03 Medical House Plc Autoinjector with manual trigger to retract the needle
WO2010053574A1 (en) * 2008-11-07 2010-05-14 Becton, Dickinson And Company Pen needle assembly for intradermal medication injection
WO2012073035A1 (en) * 2010-12-02 2012-06-07 Oval Medical Technologies Limited Delivery mechanism for an autoinjector

Also Published As

Publication number Publication date
GB201212915D0 (en) 2012-09-05

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