Spacer assembly for a drug delivery system

Abstract

To provide a drug delivery system for injecting a medicament.SOLUTION: A drug delivery system for injecting a medicament, the drug delivery system comprising: a barrel configured to contain a medicament; a stopper movably disposed within the barrel; and a drive assembly comprising: A drug delivery system, comprising: a first plunger coupled to the stopper; a second plunger telescopically coupled to the first plunger; and a drive assembly comprising: a rotatable indicator coupled to the first and second plungers and configured such that rotation of the rotatable indicator moves the first and second plungers in an axial direction; and a constant force spring coupled to the rotatable indicator to drive rotation of the rotatable indicator.SELECTED DRAWING: Figure 89

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to syringe devices and methods for delivering fluids into a patient's body by injection. [Background technology]

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 62 / 347,911, filed June 9, 2016, and U.S. Patent Application No. 15 / 616,183, filed June 7, 2017, each of which is incorporated herein by reference in its entirety.

[0003] Various types of automatic injection devices have been developed to allow untrained individuals to administer or self-inject medications and other therapeutic liquid formulations. These devices generally include a reservoir prefilled with the therapeutic liquid formulation and some type of automatic needle injection mechanism that can be activated by the user. When the volume of fluid or medication to be administered is below a certain volume, typically 1 mL, an autoinjector, typically having an injection time of approximately 10 to 15 seconds, is typically used. When the volume of fluid or medication to be administered exceeds 1 mL, the injection time generally becomes longer, making it more difficult for the patient to maintain contact between the device and the target area of ​​the patient's skin. Furthermore, as the volume of medication to be administered increases, it becomes desirable to increase the duration of the injection. The conventional method for slowly injecting medication into a patient is to initiate an intravenous injection to slowly inject the medication into the patient's body. Such procedures are typically performed in a hospital or outpatient setting.

[0004] Certain devices allow for self-injection in a home environment and can slowly inject the liquid therapeutic formulation into a patient's skin. In some cases, these devices are small enough (both in height and overall size) to allow them to be "worn" by the patient while the liquid therapeutic formulation is being injected into the patient. These devices typically include a pump or other type of delivery mechanism to force the liquid therapeutic formulation out of the reservoir and into the injection needle. Such devices also typically include a valve or flow control mechanism to initiate the flow of the liquid therapeutic formulation at the appropriate time, and a triggering mechanism to begin the injection. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2013 / 155153 Brochure [Patent Document 2] International Publication No. 2014 / 179774 Brochure [Patent Document 3] International Publication No. 2015 / 081337 Brochure Summary of the Invention [Means for solving the problem]

[0006] In one embodiment, a drug delivery system for injecting a medicament includes a container configured to receive the medicament, the container including a stopper and a closure, the stopper configured to move within the container from a pre-use position to a post-use position. The system includes a drive assembly configured to move the stopper between a first position and a second position, and a spacer assembly configured to engage with the stopper of the container and be engaged by the drive assembly. The spacer assembly includes a first spacer portion received within the stopper, a second spacer portion spaced a predetermined distance from the first spacer portion, an inner plunger, and a spacer shuttle received by the inner plunger. The inner plunger, spacer shuttle, and second portion are configured to move relative to the stopper, with movement of the second spacer portion limited by the spacer shuttle, movement of the spacer shuttle limited by the inner plunger, and movement of the inner plunger limited by the stopper.

[0007] The inner plunger can have a first portion and a second portion axially spaced from the first portion, and the spacer shuttle is restricted from axial movement when the inner plunger is in the first position and movable relative to the stopper when the inner plunger is in the second position. The second spacer portion can be restricted from axial movement via the spacer shuttle when the inner plunger is in the first position and movable relative to the stopper when the inner plunger is in the second position. The stopper can have a closed first end and a second open end, and the closed first end of the stopper is axially movable relative to the container between a use position in which the closed first end of the stopper is engaged with the inner plunger and an end-of-dosing position in which the closed first end of the stopper is spaced from the inner plunger, and the inner plunger is freely movable from the first position to the second position when the stopper is in the end-of-dosing position. The stopper can be configured to move between the use position and the end-of-dosing position based on engagement with a medicament received in the container.

[0008] The stopper can have a closed first end and a second open end, the closed first end of the stopper being axially movable relative to the container between a use position in which the closed first end of the stopper is engaged with the inner plunger and a dosing end position in which the closed first end of the stopper is spaced from the inner plunger, and the inner plunger is freely movable from the first position to the second position when the stopper is in the dosing end position. The stopper can be configured to move between the use position and the dosing end position based on engagement with a medicament received in the container. Movement of the second portion of the spacer assembly a predetermined distance can be configured to cause the drive assembly to retract the needle. The spacer shuttle can be rotatable relative to the inner plunger, and axial displacement of the second portion of the spacer assembly is configured to cause rotation of the spacer shuttle. The second portion of the spacer assembly can define an access opening configured to allow direct engagement of the first spacer portion of the spacer assembly.

[0009] In a further aspect, a spacer assembly for a drug delivery system for injecting a medicament includes a first spacer portion configured to be received by a stopper, a second spacer portion spaced a predetermined distance from the first spacer portion, an inner plunger, and a spacer shuttle received by the inner plunger, wherein the inner plunger, the spacer shuttle, and the second spacer portion are configured to move relative to the first spacer portion, and movement of the second spacer portion is limited by the spacer shuttle, and movement of the spacer shuttle is limited by the inner plunger.

[0010] The inner plunger can have a first position and a second position axially spaced from the first position, and the spacer shuttle can be restricted from axial movement when the inner plunger is in the first position and movable relative to the stopper when the inner plunger is in the second position. The second spacer portion can be restricted from axial movement via the spacer shuttle when the inner plunger is in the first position and movable relative to the stopper when the inner plunger is in the second position. The second portion of the spacer assembly can be freely movable toward the first portion of the spacer assembly when the first plunger is in the second position. The spacer shuttle can be rotatable relative to the inner plunger, and axial displacement of the second portion of the spacer assembly is configured to cause rotation of the spacer shuttle. The second spacer portion of the spacer assembly can define an access opening configured to allow direct engagement of the first spacer portion of the spacer assembly. The first portion of the spacer assembly and the second portion of the spacer assembly can be fixed to each other while allowing relative axial movement over a predetermined distance.

[0011] In a further aspect, a drug delivery system for injecting a medicament includes a container configured to receive the medicament, the container including a stopper and a closure, the stopper configured to move within the container from a pre-use position to a post-use position. The system also includes a spacer assembly including a fixed spacer and an adjustable spacer, the fixed spacer received by the stopper. The adjustable spacer is secured to the fixed spacer and is movable a predetermined axial distance relative to the spacer assembly.

[0012] The adjustable spacer can be movable only in a first axial direction relative to the fixed spacer. The spacer assembly can include a ratchet mechanism, wherein one of the fixed spacer and the adjustable spacer includes a plurality of detents and the other of the fixed spacer and the adjustable spacer includes a spring detent arm, and wherein rotation of the adjustable spacer in a first rotational direction relative to the fixed spacer moves the adjustable spacer a predetermined axial distance. The system can also include a shim configured to be secured to the adjustable spacer.

[0013] In a further aspect, a drug delivery system for injecting a medicament includes a container configured to receive the medicament, the container including a stopper configured to move within the container and a closure, and a drive assembly, the drive assembly including a plunger member configured to move the stopper within the container, the plunger member having a first position and a second position axially spaced from the first position, a biasing member configured to move the plunger member from the first position to the second position, and a plunger actuation member movable relative to the plunger member. The plunger actuation member has a first position where the plunger member is axially fixed relative to the plunger actuation member and a second position where the plunger member is axially movable relative to the plunger actuation member. The system also includes a needle actuator assembly including a needle configured to be in fluid communication with the container, the needle being movable between the first position and the second position spaced from the first position, a limiting member configured to limit movement of the needle actuator assembly, and a spacer assembly including a fixed spacer and an adjustable spacer, the fixed spacer being received by the stopper. The adjustable spacer is secured to the fixed spacer and is movable a predetermined axial distance relative to the spacer assembly.

[0014] The restricting member may be configured to engage a rear portion of the container. [Brief explanation of the drawings]

[0015] These and other features and advantages of the present disclosure, as well as methods for achieving them, will become more apparent, and the disclosure itself will be better understood, by referring to the following description of embodiments of the present disclosure in conjunction with the accompanying drawings.

[0016] [Figure 1] 1 is a perspective view of a drug delivery system according to one embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional perspective view of the drug delivery system of FIG. 1 according to one embodiment of the present invention. [Figure 3] FIG. 2 is a cross-sectional front view of the drug delivery system of FIG. 1 according to one embodiment of the present invention. [Figure 4] 2 is a top view of the drug delivery system of FIG. 1 showing the drug delivery system in a pre-use position with a top portion of the housing removed according to one embodiment of the present invention. [Figure 5] 2 is a cross-sectional top view of the drug delivery system of FIG. 1 according to one embodiment of the present invention, showing the drug delivery system in a pre-use position. [Figure 6] 2 is a cross-sectional front view of the drug delivery system of FIG. 1 showing the drug delivery system in a pre-use position according to one embodiment of the present invention. [Figure 7] 2 is a top view of the drug delivery system of FIG. 1 showing the drug delivery system in an initial actuated position with the top portion of the housing removed, according to one embodiment of the present invention. [Figure 8] 2 is a cross-sectional top view of the drug delivery system of FIG. 1 according to one embodiment of the present invention, showing the drug delivery system in an initial actuated position. [Figure 9] 2 is a cross-sectional front view of the drug delivery system of FIG. 1 according to one embodiment of the present invention, showing the drug delivery system in an initial actuated position. [Figure 10] 2 is a top view of the drug delivery system of FIG. 1 showing the drug delivery system in a position of use with a top portion of the housing removed according to one embodiment of the present invention. [Figure 11]2 is a cross-sectional top view of the drug delivery system of FIG. 1 according to one embodiment of the present invention, showing the drug delivery system in a position of use. [Figure 12] 2 is a cross-sectional front view of the drug delivery system of FIG. 1 showing the drug delivery system in a position of use according to one embodiment of the present invention. [Figure 13] 2 is a top view of the drug delivery system of FIG. 1 showing the drug delivery system in a post-use position with a top portion of the housing removed according to one embodiment of the present invention. [Figure 14] 2 is a cross-sectional top view of the drug delivery system of FIG. 1 showing the drug delivery system in a post-use position according to one embodiment of the present invention. [Figure 15] 2 is a cross-sectional front view of the drug delivery system of FIG. 1 showing the drug delivery system in a post-use position according to one embodiment of the present invention. [Figure 15A] 2 is a cross-sectional front view of the drug delivery system of FIG. 1 in a pre-use position and showing the pad according to one embodiment of the present invention. FIG. [Figure 15B] 2 is a cross-sectional perspective view of the drug delivery system of FIG. 1 in a pre-use position and showing the pad according to one embodiment of the present invention. FIG. [Figure 15C] 2 is a cross-sectional perspective view of the drug delivery system of FIG. 1 in a pre-use position and showing the pad according to one embodiment of the present invention. FIG. [Figure 16] 2 is a partial cross-sectional view of the drug delivery system of FIG. 1 showing a valve assembly according to one embodiment of the present invention. [Figure 17] FIG. 1 is a perspective view of a drive assembly for a drug delivery system according to one embodiment of the present invention. [Figure 18] 18 is a cross-sectional view of the drive assembly of FIG. 17 showing the drive assembly in a pre-use position according to one embodiment of the present invention. [Figure 19] 18 is a cross-sectional view of the drive assembly of FIG. 17 showing the drive assembly in an in-use position according to one embodiment of the present invention. [Figure 20] 18 is a cross-sectional view of the drive assembly of FIG. 17 showing a post-use position of the drive assembly according to one embodiment of the present invention. [Figure 21] FIG. 18 is a cross-sectional view of a plunger actuation member of the drive assembly of FIG. 17 according to one embodiment of the present invention. [Figure 22] FIG. 18 is a perspective view of a first plunger member of the drive assembly of FIG. 17 according to one embodiment of the present invention. [Figure 23] 18 is a perspective view of the plunger actuation member and first plunger member of the drive assembly of FIG. 17 according to one embodiment of the present invention, showing the plunger actuation member engaged with the first plunger member. FIG. [Figure 24] FIG. 18 is a perspective view of the plunger actuation member and first plunger member of the drive assembly of FIG. 17 according to one embodiment of the present invention, showing the plunger actuation member disengaged from the first plunger member. [Figure 25] FIG. 18 is a perspective view of the plunger actuating member and first plunger member of the drive assembly of FIG. 17 according to one embodiment of the present invention, showing the plunger actuating member disengaged from and axially displaced relative to the first plunger member. [Figure 26] FIG. 18 is a front view of the first plunger member and the second plunger member of the drive assembly of FIG. 17 according to one embodiment of the present invention. [Figure 27] FIG. 10 is a top view of a drive assembly for a drug delivery system according to a further aspect of the present invention. [Figure 28] FIG. 28 is a perspective view of the drive assembly of FIG. 27 according to one embodiment of the present invention. [Figure 29] FIG. 28 is a cross-sectional view of the drive assembly of FIG. 27 showing the drive assembly in a pre-use position according to one embodiment of the present invention. [Figure 30] FIG. 28 is a perspective view of the drive assembly of FIG. 27, showing the drive assembly received by the bottom portion of the housing, according to one embodiment of the present invention. [Figure 31] FIG. 31 is a perspective view of the housing of FIG. 30 according to one embodiment of the present invention. [Figure 32] 28 is a top view of the drive assembly of FIG. 27 showing engagement of the drive assembly with a portion of the needle actuator in an initial actuated position of the drive assembly according to one embodiment of the present invention. [Figure 33]28 is an enlarged perspective view of the drive assembly of FIG. 27 showing engagement of the drive assembly with a portion of the needle actuator in the actuated position of the drive assembly according to one embodiment of the present invention. FIG. [Figure 34] FIG. 1 is a front view of a needle actuator assembly according to one embodiment of the present invention. [Figure 35] FIG. 35 is a left perspective view of the needle shuttle of the needle actuator assembly of FIG. 34 according to one embodiment of the present invention. [Figure 36] FIG. 35 is a right-side perspective view of the needle shuttle of the needle actuator assembly of FIG. 34 according to one embodiment of the present invention. [Figure 37A] FIG. 35 is a front view of the needle actuator assembly of FIG. 34 showing the needle actuator assembly in a pre-use position according to one embodiment of the present invention. [Figure 37B] FIG. 35 is a front view of the needle actuator assembly of FIG. 34 showing the needle actuator assembly in the use position according to one embodiment of the present invention. [Figure 37C] FIG. 35 is a front view of the needle actuator assembly of FIG. 34 showing the needle actuator assembly in an initial, post-use position according to one embodiment of the present invention. [Figure 37D] FIG. 35 is a front view of the needle actuator assembly of FIG. 34 showing the needle actuator assembly in a post-use position according to one embodiment of the present invention. [Figure 38A] FIG. 35 is a perspective view of the needle actuator assembly of FIG. 34 showing the needle actuator assembly in a use position according to one embodiment of the present invention. [Figure 38B] FIG. 35 is a perspective view of the needle actuator assembly of FIG. 34 showing the needle actuator assembly in an initial, post-use position according to one embodiment of the present invention. [Figure 39] FIG. 35 is a perspective view of an actuator button and the needle actuator assembly of FIG. 34, showing the needle actuator assembly in an initial, post-use position, according to one embodiment of the present invention. [Figure 40A] 35 is a cross-sectional view of an actuator button and needle actuator assembly of FIG. 34 according to one embodiment of the present invention, showing the needle actuator assembly in an initial, post-use position. FIG. [Figure 40B] FIG. 35 is a perspective view of an actuator button and the needle actuator assembly of FIG. 34, showing the needle actuator assembly in a post-use position, according to one embodiment of the present invention. [Figure 41] FIG. 10 is a perspective view of a drive assembly for a drug delivery system according to a further aspect of the present invention. [Figure 42] FIG. 42 is a perspective view of the drive assembly of FIG. 41 with the top portion of the housing removed, according to one embodiment of the present invention. [Figure 43] FIG. 42 is a cross-sectional view of the drive assembly of FIG. 41 according to one embodiment of the present invention. [Figure 44] FIG. 42 is a perspective view of the drive assembly of FIG. 41 according to one embodiment of the present invention. [Figure 45] FIG. 42 is a cross-sectional view of the drive assembly of FIG. 41 showing the drive assembly in a pre-use position according to one embodiment of the present invention. [Figure 46] FIG. 42 is a cross-sectional view of the drive assembly of FIG. 41 showing the drive assembly in a pre-use position according to one embodiment of the present invention. [Figure 47] FIG. 42 is a top view of the drive assembly of FIG. 41 in accordance with one embodiment of the present invention, showing the drive assembly in a pre-use position. [Figure 48] FIG. 42 is a top view of the drive assembly of FIG. 41 in accordance with one embodiment of the present invention, showing the drive assembly in an initial actuated position. [Figure 49] FIG. 42 is a top view of the drive assembly of FIG. 41 in accordance with one embodiment of the present invention, showing the drive assembly in an initial actuated position. [Figure 50] FIG. 42 is a top view of the drive assembly of FIG. 41 in accordance with one embodiment of the present invention, showing the drive assembly in an initial actuated position. [Figure 51] FIG. 42 is a top view of the drive assembly of FIG. 41 in accordance with one embodiment of the present invention, showing the drive assembly in an in-use position. [Figure 52] FIG. 42 is a top view of the drive assembly of FIG. 41 in accordance with one embodiment of the present invention, showing the drive assembly in an in-use position. [Figure 53] FIG. 42 is a cross-sectional view of the drive assembly of FIG. 41 showing the drive assembly in an in-use position according to one embodiment of the present invention. [Figure 54] FIG. 42 is a top view of the drive assembly of FIG. 41 in accordance with one embodiment of the present invention, showing the drive assembly in an in-use position. [Figure 55] FIG. 42 is a cross-sectional view of the drive assembly of FIG. 41 showing the drive assembly in an in-use position according to one embodiment of the present invention. [Figure 56] FIG. 42 is a cross-sectional view of the drive assembly of FIG. 41 showing the drive assembly in an in-use position according to one embodiment of the present invention. [Figure 57] FIG. 42 is a top view of the drive assembly of FIG. 41 in accordance with one embodiment of the present invention, showing the drive assembly in an in-use position. [Figure 58] FIG. 42 is a top view of the drive assembly of FIG. 41 showing the drive assembly in an initial, post-use position according to one embodiment of the present invention. [Figure 59] FIG. 42 is a perspective view of the drive assembly of FIG. 41 showing the drive assembly in an initial, post-use position according to one embodiment of the present invention. [Figure 60] FIG. 42 is a top view of the drive assembly of FIG. 41 showing the drive assembly in a post-use position according to one embodiment of the present invention. [Figure 61] FIG. 42 is a top view of the drive assembly of FIG. 41 showing the drive assembly in a post-use position according to one embodiment of the present invention. [Figure 62] FIG. 42 is a cross-sectional view of the drive assembly of FIG. 41 showing the drive assembly in a pre-use position according to one embodiment of the present invention. [Figure 63] FIG. 42 is a cross-sectional view of the drive assembly of FIG. 41 showing the drive assembly in an in-use position according to one embodiment of the present invention. [Figure 64] FIG. 10 is a perspective view of a drive assembly according to a further aspect of the present invention. [Figure 65A] FIG. 1 is a front view of a needle actuator assembly according to one embodiment of the present invention, showing the needle actuator assembly in a use position. [Figure 65B] FIG. 65B is a front view of the needle actuator assembly of FIG. 65A according to one embodiment of the present invention, showing the needle actuator assembly in the use position. [Figure 65C]FIG. 65B is a front view of the needle actuator assembly of FIG. 65A showing the needle actuator assembly in an initial, post-use position according to one embodiment of the present invention. [Figure 65D] FIG. 65B is a front view of the needle actuator assembly of FIG. 65A showing the needle actuator assembly in a post-use position according to one embodiment of the present invention. [Figure 65E] FIG. 65B is a front view of the needle actuator assembly of FIG. 65A according to one embodiment of the present invention, showing the needle actuator assembly in a pre-use position. [Figure 65F] FIG. 65B is a cross-sectional view of the needle actuator assembly of FIG. 65A according to one embodiment of the present invention, showing the needle actuator assembly in a pre-use position. [Figure 65G] FIG. 65B is a front view of the needle actuator assembly of FIG. 65A showing the needle actuator assembly in a pre-use position with the button actuator axially displaced according to one embodiment of the present invention. [Figure 65H] FIG. 65B is a cross-sectional view of the needle actuator assembly of FIG. 65A showing the needle actuator assembly in a pre-use position with the button actuator axially displaced according to one embodiment of the present invention. [Figure 66] FIG. 65B is a perspective view of a button spring of the needle actuator assembly of FIG. 65A according to one embodiment of the present invention. [Figure 67] FIG. 65B is a perspective view of an actuator button of the needle actuator assembly of FIG. 65A according to one embodiment of the present invention. [Figure 68] FIG. 65B is a cross-sectional view of the button spring and actuator button of the needle actuator assembly of FIG. 65A according to one embodiment of the present invention. [Figure 68A] FIG. 65B is a perspective view of an actuator button of the needle actuator assembly of FIG. 65A according to a further embodiment of the present invention. [Figure 68B] FIG. 65B is a bottom view of the actuator button of the needle actuator assembly of FIG. 65A according to a further embodiment of the present invention. [Figure 68C] FIG. 65B is a front view of an actuator button of the needle actuator assembly of FIG. 65A according to a further embodiment of the present invention. [Figure 68D] FIG. 65B is a top view of the actuator button of the needle actuator assembly of FIG. 65A according to a further embodiment of the present invention, showing the actuator button in a pre-use position. [Figure 68E] FIG. 65B is a front view of the actuator button of the needle actuator assembly of FIG. 65A according to a further embodiment of the present invention, showing the actuator button in a pre-use position. [Figure 68F] FIG. 65B is a top view of the actuator button of the needle actuator assembly of FIG. 65A according to a further embodiment of the present invention, showing the actuator button in a use position. [Figure 68G] FIG. 65B is a front view of the actuator button of the needle actuator assembly of FIG. 65A according to a further embodiment of the present invention, showing the actuator button in the use position. [Figure 69] FIG. 65B is a top view of the actuator button of the needle actuator assembly of FIG. 65A according to one embodiment of the present invention. [Figure 70A] FIG. 2 is a schematic diagram of a drive assembly according to one embodiment of the present invention, showing the drive assembly in a pre-use position. [Figure 70B] FIG. 70B is a schematic diagram of the drive assembly of FIG. 70A according to one embodiment of the present invention, showing the drive assembly in a use position. [Figure 70C] FIG. 70B is a schematic diagram of the drive assembly of FIG. 70A according to one embodiment of the present invention, showing the drive assembly in a use position. [Figure 70D] FIG. 70B is a schematic diagram of the drive assembly of FIG. 70A according to one embodiment of the present invention, showing the drive assembly in a use position. [Figure 70E] FIG. 70B is a schematic diagram of the drive assembly of FIG. 70A according to one embodiment of the present invention, showing the drive assembly in a use position. [Figure 70F] FIG. 70B is a schematic diagram of the drive assembly of FIG. 70A showing the drive assembly in a post-use position according to one embodiment of the present invention. [Figure 70G] FIG. 70B is a schematic diagram of the drive assembly of FIG. 70A showing the drive assembly in a post-use position according to one embodiment of the present invention. [Figure 71]1 is a perspective view of a spacer assembly of a drug delivery system according to one embodiment of the present invention, showing the spacer assembly in an assembled, pre-use position. FIG. [Figure 72] FIG. 72 is a perspective view of the spacer assembly of FIG. 71 showing the spacer assembly in use position according to one embodiment of the present invention. [Figure 73] 72 is a perspective view of the spacer assembly of FIG. 71 showing the initial, post-use position of the spacer assembly according to one embodiment of the present invention. [Figure 74] FIG. 1 is a perspective view of a restricting member according to one embodiment of the present invention. [Figure 75] FIG. 10 is a front view of a spacer assembly for a drug delivery system according to a further aspect of the present invention. [Figure 76] FIG. 1 is a top view of a spacer assembly for a drug delivery system according to one embodiment of the present invention. [Figure 77] FIG. 77 is a perspective view of the spacer assembly of FIG. 76 according to one embodiment of the present invention. [Figure 78] FIG. 77 is a cross-sectional view of the spacer assembly of FIG. 76 according to one embodiment of the present invention. [Figure 79] FIG. 10 is a perspective view of a spacer assembly for a drug delivery system according to a further aspect of the present invention. [Figure 80] FIG. 10 is a perspective view of a spacer assembly for a drug delivery system according to another aspect of the present invention. [Figure 81A] 81 is a cross-sectional view of the spacer assembly of FIG. 80 showing a pre-assembly position of the spacer assembly according to one embodiment of the present invention. [Figure 81B] 81 is a cross-sectional view of the spacer assembly of FIG. 80 showing the spacer assembly in an assembled position according to one embodiment of the present invention. [Figure 82] FIG. 1 is a perspective view of a drive assembly for a drug delivery system according to one embodiment of the present invention. [Figure 83] FIG. 83 is a perspective view of the drive assembly of FIG. 82 with the top portion of the housing removed, according to one embodiment of the present invention. [Figure 84] FIG. 83 is a cross-sectional view of the drive assembly of FIG. 82 showing the drive assembly in a pre-use position according to one embodiment of the present invention. [Figure 85] FIG. 83 is an enlarged cross-sectional view of the drive assembly of FIG. 82 showing the drive assembly in a pre-use position according to one embodiment of the present invention. [Figure 86] FIG. 83 is a top view of a biasing member of the drive assembly of FIG. 82 according to one embodiment of the present invention. [Figure 87] FIG. 83 is a perspective view of the drive assembly of FIG. 82 showing the limiting member engaged with the drive assembly according to one embodiment of the present invention. [Figure 88] FIG. 1 is a perspective view of a drive assembly for a drug delivery system according to one embodiment of the present invention. [Figure 89] FIG. 89 is a perspective view of the drive assembly of FIG. 88 showing the drive assembly in a pre-use position according to one embodiment of the present invention. [Figure 90] FIG. 89 is a cross-sectional view of the drive assembly of FIG. 88 according to one embodiment of the present invention. [Figure 91] FIG. 89 is a perspective view of the drive assembly of FIG. 88 showing the drive assembly in a post-use position according to one embodiment of the present invention. [Figure 92] FIG. 89 is a cross-sectional view of the drive assembly of FIG. 88 showing the drive assembly in a pre-use position according to one embodiment of the present invention. [Figure 93] FIG. 89 is a front view of the drive assembly of FIG. 88 according to one embodiment of the present invention, showing the drive assembly in use position. [Figure 94] FIG. 1 is a perspective view of a spacer assembly for a drug delivery system according to one embodiment of the present invention. [Figure 95] FIG. 95 is a front view of the spacer assembly of FIG. 94 according to one embodiment of the present invention. [Figure 96] FIG. 95 is a cross-sectional view of the spacer assembly of FIG. 94 according to one embodiment of the present invention. [Figure 97] FIG. 95 is a perspective view of the spacer assembly of FIG. 94 shown with the shim removed according to one embodiment of the present invention. [Figure 98] FIG. 95 is a perspective view of a fixed spacer of the spacer assembly of FIG. 94 according to one embodiment of the present invention. [Figure 99] FIG. 95 is a perspective view of an adjustable spacer of the spacer assembly of FIG. 94 according to one embodiment of the present invention. [Figure 100] FIG. 95 is a perspective view of a shim of the spacer assembly of FIG. 94 according to one embodiment of the present invention.

[0017] Corresponding reference characters indicate corresponding parts throughout the several views. The illustrations presented herein illustrate exemplary embodiments of the present disclosure, and such illustrations should not be construed as limiting the scope of the present disclosure in any way. DETAILED DESCRIPTION OF THE INVENTION

[0018] The following description is provided to enable those skilled in the art to make and use the described embodiments contemplated for carrying out the invention. However, various modifications, equivalents, variations, and alternatives will remain readily apparent to those skilled in the art. All such modifications, variations, equivalents, and alternatives are intended to be within the spirit and scope of the present invention.

[0019] In the following description, the terms "upper," "lower," "right," "left," "vertical," "horizontal," "top," "bottom," "lateral," "longitudinal," and their derivatives refer to the present invention as oriented in the drawings. However, it should be understood that the present invention is capable of various alternative forms, unless expressly stated otherwise. It should also be understood that the specific devices illustrated in the accompanying drawings and described in the following detailed description are merely exemplary embodiments of the present invention. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered limiting.

[0020] 1-16, a drug delivery system 10 according to one embodiment of the present invention includes a drive assembly 12, a reservoir 14, a valve assembly 16, and a needle actuator assembly 18. The drive assembly 12, the reservoir 14, the valve assembly 16, and the needle actuator assembly 18 are at least partially positioned within a housing 20. The housing 20 includes a top portion 22 and a bottom portion 24, although other suitable configurations for the housing 20 may be utilized. In one embodiment, the drug delivery system 10 is an injector device configured to be worn or secured to a user and configured to deliver a predetermined dose of a medication provided in the reservoir 14 into the user's body via injection. The system 10 may be utilized to deliver a "bolus injection," in which the medication is delivered within a set period of time. The medication may be delivered over a period of up to 45 minutes, although other suitable injection volumes and durations may be utilized. The bolus administration or delivery may be performed with or without specific rate control. System 10 can deliver medication to a user at a constant pressure with variable rates. The general operation of system 10 is described below with reference to Figures 1-16, and details of drive assembly 12, needle actuator assembly 18, and other features of system 10 are discussed below in connection with Figures 17-93.

[0021] 1-16, system 10 is configured to operate via engagement of actuator button 26 by a user, which results in puncture of the user's skin by needle 28 of needle assembly 18; actuation of drive assembly 12, which places needle 28 in fluid communication with container 14 to expel fluid or medication from container 14; and withdrawal of needle 28 after medication injection is complete. The general operation of a drug delivery system is shown and described (e.g., see U.S. Patent Nos. 5,629,992 and 5,729,992, which are incorporated herein by reference in their entireties). Housing 20 of system 10 includes an indicator window 30 for viewing an indicator mechanism 32 configured to provide a user with an indication regarding the status of system 10, and a container window 31 for viewing container 14. Indicator window 30 may be a magnifying glass to provide a clearly visible status of indicator mechanism 32. Indicator mechanism 32 moves with needle actuator assembly 18 during use of system 10 to indicate the pre-use, use, and post-use states of system 10. The indicator mechanism 32 provides a visual indication of the status, although other suitable indications, such as audible or tactile, may be provided as alternative or additional indications.

[0022] 4-6, during the pre-use position of system 10, container 14 is spaced apart from drive assembly 12 and valve assembly 16, and needle 28 is in a retracted position. As shown in FIGS. 7-9, during initial actuation of system 10, drive assembly 12 engages container 14 and moves container 14 toward valve assembly 16, which is configured to pierce closure 36 of container 14 and place medicament within container 14 in fluid communication with needle 28 via tubing (not shown) or other suitable mechanism. Drive assembly 12 is configured to engage stopper 34 of container 14, which initially moves the entire container 14 into engagement with valve assembly 16 due to the incompressibility of the fluid or medicament within container 14. Initial actuation of system 10 is triggered by engagement of actuator button 26 by a user, which releases needle actuator assembly 18 and drive assembly 12, as discussed in more detail below. During initial actuation, needle 28 is still in the retracted position and is about to move to the extended position to inject the user of system 10 .

[0023] As shown in FIGS. 10-12 , during the use position of system 10, needle 28 is at least partially outside of housing 20 in an extended position, and drive assembly 12 is moving stopper 34 within container 14 to deliver medication from container 14 through needle 28 to the user. In the use position, valve assembly 16 has already pierced closure 36 of container 14, placing container 14 in fluid communication with needle 28, which also allows drive assembly 12 to move stopper 34 relative to container 14 so that fluid can be dispensed from container 14. As shown in FIGS. 13-15 , in the post-use position of system 10, needle 28 is in a retracted position and engaged with pad 38, which seals needle 28 and prevents any residual flow of fluid or medication from container 14. Container 14 and valve assembly 16 may be the container 14 and valve assembly 16 shown and described in U.S. Patent Application Publication No. 2009 / 0129994, which is incorporated herein by reference in its entirety.

[0024] 15A-15C, the pad 38 is biased into the needle actuator body 96 as it moves from the use position to the post-use position. Specifically, the pad 38 is received by a pad arm 122 having a cam surface 124 that cooperates with a cam track 126 on the bottom portion 24 of the housing 20. The pad arm 122 is connected to the needle actuator body 96 via a torsion bar 128. The cam surface 124 is configured to engage the cam track 126 and bias the pad arm 122 downward, thereby allowing the pad 38 to pass directly beneath the needle 28 before being biased upward toward the needle 28. The torsion bar 128 allows the pad arm 122 to twist about a pivot on the needle actuator body 96. The pad 38 may be press-fit into the opening in the pad arm 122, although other suitable configurations for securing the pad 38 may be utilized.

[0025] Referring to Figures 1-33, a drive assembly 12 according to one embodiment of the present invention is shown. As described above, the drive assembly 12 is configured to move a container 14 to pierce a closure 36 of the container 14 and to move a stopper 34 within the container 14 to dispense a fluid or medication from the container 14. The drive assembly 12 shown in Figures 17-33 is configured to engage and cooperate with a spacer assembly 40 that is received by the stopper 34 of the container 14. The spacer assembly 40 includes a spacer 42 and a spacer retainer 44. The spacer retainer 44 is received by the stopper 34, and the spacer 42 is received by the spacer retainer 44. The spacer retainer 44 includes a first threaded portion 46 that engages a corresponding threaded portion of the stopper 34, although other suitable configurations may be utilized. The spacer 42 also includes a threaded portion 48 that engages a corresponding second threaded portion 50 of the spacer retainer 44 to secure the spacer 42 to the spacer retainer 44, although other suitable configurations may be utilized. The drive assembly 12 is configured to dispense a range of predetermined fill volumes of the container 14 while maintaining the functional features of the system 10 described above, including, but not limited to, retracting the needle 28 after completion of administration and providing an indication of the status of the system 10, and while minimizing accidental engagement of the stopper 34 by the drive assembly 12. The drive assembly 12 is configured to dispense multiple discrete fill volume ranges by utilizing multiple sizes of spacers 42. In one embodiment, 12 fill volume ranges and 12 spacer 42 sizes are provided. In one embodiment, the length of the spacer 42 is varied to accommodate various fill volumes in the container 14. Alternatively, a single size spacer 42 may be utilized, with multiple fill volumes in the container 14 accommodated by utilizing multiple shims received by the spacer 42.

[0026] 17-26, the drive assembly 12 includes a first plunger member 52, a second plunger member 54 received by the first plunger member 52, a first biasing member 56, a second biasing member 58, a plunger actuation member 60, and an indexing member 62. The first plunger member 52 is movable from a pre-use position (shown in FIG. 18), to a use position (shown in FIG. 19), to a post-use position (shown in FIG. 20), and the first plunger member 52 is configured to engage the spacer assembly 40 and move the stopper 34 within the container 14 to dispense the medicament from the container 14. The first plunger member 52 is configured to move axially. The second plunger member 54 and the first plunger member 52 form a telescopic configuration, and the second plunger 54 is configured to move axially after the first plunger member 52 has moved a predetermined axial distance. Movement of the first and second plunger members 52, 54 is achieved by first and second biasing members 56, 58 which are compression springs, although other suitable configurations for the biasing members 56, 58 may be utilized.

[0027] The first biasing member 56 is received by the second plunger member 54 and is captured between the plunger actuation member 60 (and indexing member 62) and the first spring seat 64 of the second plunger member 54. The second biasing member 58 is positioned radially inward from the first biasing member 56 and is received by the second plunger member 54. The second biasing member 58 is captured between the second spring seat 66 of the second plunger member 54 and the first plunger member 54. The second biasing member 58 is configured to bias the first plunger member 52 from a pre-use position to a use position and then to a post-use position toward the container 14. The first biasing member 56 is configured to bias the second plunger member 54 toward the container 14, which sequentially biases the first plunger member 52 from a pre-use position to a use position and then to a post-use position toward the container 14. More specifically, the second biasing member 58 is configured to press the first plunger member 52 against the spacer assembly 40 or the stopper 34 to move the container 14 into engagement with the valve assembly 16, thereby piercing the closure 36 of the container 14 and placing the container 14 in fluid communication with the needle 28. The first biasing member 56 is configured to move the stopper 34 within the container 14 to dispense the medicament from the container 14. The second biasing member 58 has a different spring constant than the first biasing member 56. Specifically, the second biasing member 58 is stiffer than the first biasing member 56 to provide a greater force for piercing the closure 36 of the container 14, while the first biasing member 56 provides a weaker force for dispensing, consistent with the viscosity of the fluid or medicament within the container 14.

[0028] 17-26, the plunger actuation member 60 has an annular portion 68 and a spindle portion 70. The plunger actuation member 60 is rotationally movable relative to the first plunger member 52 between a first rotational position and a second rotational position spaced apart from the first rotational position. The first rotational position may be located 15 degrees from the second rotational position, although other suitable positions may be utilized. The annular portion 68 includes a drive surface 72 including a plurality of teeth 74, although other suitable configurations may be utilized for the drive surface 72. The spindle portion 70 includes an actuator locking surface 76 configured for engagement and disengagement with a plunger locking surface 78 of the first plunger member 52. The plunger locking surface 78 includes a plurality of protrusions 80 configured to be received by a plurality of grooves or notches 81 defined by the actuator locking surface 76.

[0029] 18 and 23, in a first rotational position of the plunger actuation member 60, the plurality of protrusions 80 and the plurality of grooves or notches 81 are misaligned such that the plunger actuation member 80 is engaged with the first plunger member 52 to prevent movement of the first and second plunger members 52, 54, with the first and second biasing members 56, 58 biasing the first and second plunger members 52, 54 away from the plunger actuation member 60. In a second rotational position of the plunger actuation member 60, as shown in FIGS. 19 and 24, the plurality of protrusions 80 and the plurality of grooves or notches 81 are aligned such that the plunger actuation member 60 is disengaged from the first plunger member 52 to allow movement of the first and second plunger members 52, 54, thereby initiating the dispensing process from the container 14.

[0030] 7 and 33, the drive surface 72 of the plunger actuation member 60 is configured to be engaged by a portion of the needle actuator assembly 18. After engagement of the actuator button 26 and release of the needle actuator assembly 18, discussed in more detail below, the needle actuator assembly 18 moves within the housing 20 from a pre-use position to a use position to a post-use position. During the initial movement of the needle actuator assembly 18, a portion of the needle actuator assembly 18 engages the drive surface 72 of the plunger actuation member 60 to move the plunger actuation member 60 from a first rotational position to a second rotational position. As shown in FIG. 33, an angled blade portion 82 of the needle actuator assembly 18 engages the drive surface 72 of the plunger actuation member 60 to cause rotation of the plunger actuation member 60.

[0031] 11, 13, and 26, the second plunger member 52 includes a plurality of coded projections 84, a pre-selected one of which is configured to engage a limiting member 86 of the system 10. As discussed in more detail below, the limiting member 86 cooperates with the needle actuation assembly 18 to limit movement of the needle actuation assembly 18 from the use position to the post-use position until a predetermined end-of-dose position of the stopper 34 is reached. In one embodiment, the limiting member 86 is configured to limit axial movement of the needle actuation assembly 18 from the use position via engagement between the limiting member 86 and a portion of the needle actuation assembly 18. Such engagement between the limiting member 86 and the needle actuation assembly 18 is released by rotation of the limiting member 86 when the stopper 34 reaches the end-of-dose position. During the use position of the needle actuator assembly 18, the restricting member 86 is rotationally biased, with rotation of the restricting member 86 prevented through engagement between the restricting member 86 and one of a plurality of coded protrusions 84 on the second plunger member 54. The plurality of coded protrusions 84 may be axial ribs of various lengths, although other suitable configurations may be utilized. Each coded protrusion 84 defines a position to which the restricting member 86 can rotate to release the needle actuator assembly 18. The smooth portion of the second plunger member may also provide an additional “code” that determines when the system 10 transitions to the end-of-dose position.

[0032] As described above, indicator mechanism 32 moves such that various portions of indicator mechanism 32 are visible through indicator window 30 as system 10 moves from a pre-use position, a use position, and a post-use or end-of-dose position. More specifically, indicator mechanism 32 engages a portion of restrictor member 86 and moves with restrictor member 86 through various stages of system 10 to provide an indication to the user regarding the status of system 10.

[0033] During assembly of the system 10, a dose in the container 14 is aligned with a particular spacer 42 having a set length, and a corresponding one of the plurality of coded projections 84 is aligned with the restrictor member 86. Thus, as described above, the container 14 can include multiple dose volumes, each volume corresponding to a particular spacer 42 and coded projection 84. Thus, even with different dose volumes, the system 10 is configured to minimize accidental engagement of the stopper 34 by the drive assembly 12 while simultaneously pricking the needle 28 into the user to deliver a dose of medication from the container 14, retracting the needle 28 after administration is complete, and providing an indication of the status of the system 10. Specifically, the size of the stopper 34 can be selected to minimize the distance between the first plunger member 52 and the spacer assembly 40 and not require the use of damping.

[0034] 27-33, a drive assembly 12A according to a further embodiment of the present invention is shown. The drive assembly 12A shown in FIGS. 27-33 is similar to and operates similarly to the drive assembly 12 shown in FIGS. 17-26 and described above. However, in the drive assembly of FIGS. 27-33, the first plunger member 52 is received by and extends from the second plunger member 54 during axial movement from the pre-use position to the use position. Additionally, the first plunger member 52 includes an extension portion 88 configured to engage the second plunger member 54 after the first plunger member 52 has moved a predetermined axial distance such that the first and second plunger members 52, 54 move together. First and second biasing members 56, 58 engage and act on first and second plunger members 52, 54 in a manner similar to drive assembly 12 of Figures 17-26.

[0035] 27-32 , the indexing member 62 includes a plurality of ratchet teeth 90 positioned about the first and second plunger members 52, 54 and configured to engage flexible tabs 92 positioned on the bottom portion 24 of the housing 20. When the drive assembly 12, 12A is installed within the bottom portion 24 of the housing 20, engagement of the ratchet teeth 90 of the indexing member 62 with the flexible tabs 92 of the housing 20 provides unidirectional rotation of the indexing member 62. The indexing member 62 is configured to align one of the coded protrusions 84 of the second plunger member 52 with the limiting member 86 based on the dose volume and spacer 42 size, as described above. The indexing member 62 may provide 24 rotational positions for the drive assembly 12, 12A, 12 of which may have unique dose values ​​associated with them.

[0036] 1-16 and 34-40B, a needle actuator assembly 18 according to one embodiment of the present invention is shown. The needle actuator assembly 18 includes a needle actuator body 96 having a guide surface 98, a needle shuttle 102 having a cam surface 104, and a needle 28 configured to be received by the needle shuttle 102 and to be in fluid communication with the container 14 as described above. The needle actuator body 96 is generally rectangular, with the guide surface 98 projecting radially inward. The needle shuttle 102 is received within the needle actuator body 96. As described above, the needle actuator body 96 is movable within the housing 20 from a pre-use position (shown in FIGS. 4-6), an initial actuated position (FIGS. 7-9), a use position (FIGS. 10-12), and a post-use position (FIGS. 13-15). The needle actuator body 96 is biased from the pre-use position to the post-use position via a tension spring 106, although other suitable biasing configurations may be utilized. The needle actuator body 96 is released to move freely from the pre-use position to the use position in response to engagement of the actuator button 26, which will be discussed in more detail below. The needle actuator body 96 moves from the use position to the post-use position following rotation of the restricting member 86 as described above in connection with Figures 17-33.

[0037] 34-40B, the needle shuttle 102 is movable along a vertical axis between a retracted position, in which the needle 28 is positioned within the housing 20, and an extended position, in which at least a portion of the needle 28 extends outside the housing 20. The needle shuttle 102 is configured to move between the retracted and extended positions through engagement between a guide surface 98 of the needle actuator 96 and a cam surface 104 of the needle shuttle 102. The cam surface 104 is provided by first and second cam members 108, 110, with the first cam member 108 being spaced apart from the second cam member 110. The housing 20 includes a guide post 112 having a recess configured to receive a T-shaped protrusion 114 on the needle shuttle 102, although other shapes and configurations may be utilized for the guide post 112 and the T-shaped protrusion 114. The needle shuttle 102 moves along the guide post 112 between the retracted and extended positions. The guide posts 112 are linear and extend generally perpendicularly from the housing 20, although other suitable configurations may be utilized. The guide surfaces 98 of the needle actuator body 86 are non-linear and each include a first side 116 and a second side 118 positioned opposite the first side 116.

[0038] As discussed below, the guide surfaces 98 of the needle actuator body 96 cooperate with the cam members 108, 110 of the needle shuttle 102 to move the needle shuttle 102 vertically between the retracted and extended positions as the needle actuator body 96 moves axially from the pre-use position to the post-use position. The needle shuttle 102 also includes a shuttle biasing member 120 configured to engage the housing 20 or the actuator button 26. Specifically, the shuttle biasing member 120 engages and provides a biasing force to the housing 20 or the actuator button 26 as the needle actuator body 96 transitions from the use position to the post-use position. When the needle actuator body 96 is fully transitioned to the post-use position, the cam members 108, 110 of the needle shuttle 102 disengage from the guide surfaces 98 of the needle actuator body 96, and the shuttle biasing member 120 biases the needle shuttle 102 downward such that the needle 28 engages the pad 38, as described above. 1-16, the pad 38 may also be biased toward the needle 28 rather than biasing the needle shuttle 102 downward via the shuttle biasing member 120. The needle actuator body 96 may interact with the actuator button 26 to prevent the actuator button 26 from bouncing back until a post-use position is reached, which is discussed in more detail below.

[0039] 37A-40B, in the pre-use position (FIG. 37A), the needle shuttle 102 is in a retracted position and the cam members 108, 110 are spaced apart from the guide surface 98 of the needle actuator body 96. As the needle actuator body 96 moves to the use position (FIGS. 37B and 38A), the second cam member 110 of the needle shuttle 102 engages the second side 118 of the guide surface 98, moving the needle shuttle 102 from the retracted position to the extended position. During transition of the needle actuator body 96 from the use position to the post-use position (FIG. 37C), the first cam member 108 of the needle shuttle 102 engages the first side 116 of the guide surface 98, moving the needle shuttle 102 from the second position to the first position. After the needle actuator body 96 is fully transitioned to the post-use position (FIGS. 37D and 38B), the shuttle biasing member 120 biases the needle shuttle 102 downward, with the needle 28 engaged with the pad 38, as the cam members 108, 110 disengage from the guiding surface 98 of the needle actuator body 96. The transition of the needle actuator body 96 and the corresponding position of the needle shuttle 102 are also shown in FIGS. 39-40B. The interaction between the actuator button 26 and the needle actuator body 96 is discussed in detail in connection with FIGS. 65A-67. Referring to FIGS. 41-64, a drug delivery system 200 according to a further embodiment is shown. The system 200 includes a housing 202 having an upper housing 204 and a lower housing 206. The housing has a proximal end 205 and a distal end 207. The upper housing 204 has a status viewing port 208 to allow a user to view the operating status of the system 200. System 200 also includes a valve assembly 212 and a tube 214 that fluidly connects valve assembly 214 with a patient needle 215 disposed within the proximal end of needle arm 216. A spring 218 biases needle actuator 220 distally.

[0040] 42-46, system 200 further includes a container or drug container 222 having a stopper 224 movably disposed therein, although stopper 224 is omitted from the various views for clarity. The distal end of drug container 222 preferably has a septum assembly 228, which is spaced from valve assembly 212 prior to actuation of device 222, as best shown in FIG.

[0041] For manufacturing purposes, it is often desirable to use one size for a drug container, even if multiple fill volumes or doses are intended for use with that container. In such cases, different fill volumes result in various stopper positions when the drug container is filled. To accommodate such various stopper positions and to accommodate stopper manufacturing variations, embodiments of the present invention include a custom or custom-made spacer 226 positioned proximal to stopper 224 within the proximal end of container 222. In other words, the custom spacer 226 provides the option of dispensing a range of predetermined fill volumes set by the manufacturer through the selection of various spacers 226, and reduces or eliminates the need for assembly work. The size of the spacer 226 can be adapted to account for the missing volume of the container 222 and to provide a consistent support surface at the proximal end of the container.

[0042] Spacer 226 is selected from a plurality of spacers 226 of various sizes to occupy the space from the proximal end of stopper 224 to the proximal end of container 222. According to one embodiment, as shown in Figures 45-47, spacer 226 is selected to be substantially flush with the proximal end of container 222. Furthermore, according to one embodiment, spacer 226 has a "top hat" shape, including a central column 230 and a distal flange 232, as best shown in Figure 45.

[0043] 44-47 , the system 200 also includes a drive assembly 234 for distally displacing the container 222 to establish a fluid connection between the container 222 and the patient needle 215 and for dispensing the medication from the container 222. More specifically, the drive assembly 234 includes an inner spring 236 disposed within a central plunger 238, an outer plunger 240, an outer spring 242 disposed between the central plunger 238 and the outer plunger 240, a telescoping member 244, and a release gate 246.

[0044] The inner spring 236 preferably has a larger spring constant than the outer spring 242 and is therefore stronger or stiffer than the outer spring 242. The inner spring 236 is disposed inside the central plunger 238 and presses between a spring flange 248 (best shown in FIG. 46 ) in the lower housing and the central plunger 238, which bears directly against the proximal end of the spacer 226 after device actuation. The outer spring 242 is disposed inside the outer plunger 240 and presses between a proximal outer flange 250 of the central plunger 238 and a distal inner flange 252 of the outer plunger 240. Thus, the inner spring 236 and the outer spring 242 can be nested to provide a more compact drive assembly (and therefore a more compact system 200) than using a single spring.

[0045] According to one embodiment, the inner spring 236 acts only to displace the container 222 and establish a fluid connection with the patient needle 215, and the outer spring 242 acts only to subsequently dispense the medication from the container 222. According to another embodiment, the inner spring 236 acts to displace the container 222 and establish a fluid connection with the patient needle 215 and also to initiate the dispense of the medication from the container 222, and the outer spring 242 also acts to complete the dispense of the medication. In a further embodiment, the inner spring 236 causes the initial piercing of the container 222, and the outer spring 242 completes the piercing and dispense of the medication from the container 222.

[0046] As shown in FIGS. 44-47, and as described in more detail below, outer plunger 240 includes a pair of proximal flanges or feet 254, each having a sloped surface that interacts with a corresponding sloped surface on the release gate to retain and subsequently release the power module after actuation of device 200.

[0047] As best shown in FIGS. 46 and 47 , when initially assembled, the container 222 is spaced apart from the drive assembly 234 and the valve assembly 212. Side flanges 256 on the needle actuator 220 axially retain the drug container 222, and the needle actuator 220 prevents the release gate 246 from displacing laterally. According to one embodiment, a spring (not shown) biases the needle actuator 220 distally, but the activation button 210 (and / or its associated assembly) prevents distal displacement of the needle actuator 220 prior to actuation of the device 200. A status bar 258 is disposed on the needle actuator 220 and has a top surface that is viewable through the status viewing port 208. According to one embodiment, the top surface of the status bar has multiple colors or patterns, and a first color or pattern, such as yellow, is visible through the status viewing port 208 when the device is in a pre-actuated state.

[0048] 48-52 are top views of system 200 illustrating operation during actuation of system 200 and subsequent events. In FIG. 47, a user slides activation button 210 proximally and then displaces button 210 vertically into housing 202, thereby allowing needle actuator 220 to displace distally under the influence of a spring (omitted for clarity). As shown in FIG. 49, as the needle actuator displaces distally, track 260 on needle actuator 220 interacts with lateral boss 262 on needle arm 216 to insert patient needle 215. At this stage, preferably, the proximal end of needle actuator 220 has not yet moved away from release gate 246, and thus drive assembly 234 has not yet been released. However, lateral flange 256 has displaced distally, and thus container 222 is unconstrained.

[0049] 50 and 51, as distal displacement continues, the proximal end of the needle actuator 220 moves away from the release gate 246 (thereby releasing the drive assembly 234). The needle actuator 220 momentarily rests against a feature on the rotatable release flipper 264, driving the release flipper 264 against the outrigger 266 (best shown in FIGS. 44 and 59) of the telescoping member 244. The needle actuator 220 remains in this position until the medication has been dispensed. In this position, a second color or pattern, such as green, of the status bar 258 is preferably visible through the status viewing port 208.

[0050] At this stage, the force of springs 236 and 242 and the interaction of the sloped surface of proximal flange or foot 254 with a corresponding sloped surface on release gate 246 displaces release gate 246 laterally, thus freeing outer plunger 240 from its constraining interaction with release gate 246. Up until this point, outer plunger 240 has been constraining central plunger 238.

[0051] 52 and 53 (inner spring 236 is omitted from FIG. 52 for clarity), stiff inner spring 236 drives central plunger 238 distally into contact with spacer 226. Because drug reservoir 222 is filled with a substantially incompressible fluid, continued distal displacement of central plunger 238 displaces spacer 226, stopper 224, and reservoir 222 distally relative to housing 202. This distal displacement causes septum assembly 228 to be pierced by valve assembly 212, establishing fluid communication between reservoir 222 and patient needle 215. Central plunger 238 moves distally until its proximal external flange 250 (best shown in FIG. 59) contacts a flange on lower housing 206, limiting the "piercing travel." Preferably, another flange on the lower housing 206 and / or a side flange 256 on the needle actuator 220 limits the distal movement of the reservoir 222 .

[0052] 54 and 55, because inner spring 236 can no longer distally displace central plunger 238, softer outer spring 242 displaces outer plunger 240 distally relative to central plunger 238 into contact with distal flange 232 of spacer 226. As will be explained in more detail below, contact between outer plunger 240 and spacer 226 is preferably damped to minimize impact forces. Further extension of outer spring 242 displaces outer plunger 240 distally, dispensing the medicament.

[0053] 56 and 57 , as outer spring 242 continues to expand and displace outer plunger 240 distally, an exterior feature or flange 268 on outer plunger 240 interacts with an interior distal feature or flange 270 of telescoping member 244 to “pick up” telescoping member 244 in response to a predetermined distal displacement of outer plunger 240 relative to telescoping member 244. This ensures that further distal displacement of outer plunger 240 results in a corresponding distal displacement of telescoping member 244. This paired distal displacement continues until the end of drug dispensing.

[0054] As previously noted, outrigger 266 is disposed on telescoping member 244. The axial length of the outrigger and the distal movement of telescoping member 144 control the timing of the engagement and disengagement of outrigger 266 with release flipper 264. As shown in FIGS. 58 and 59 , at the end of drug dispensing, the proximal end of outrigger 266 bypasses release flipper 264. This allows release flipper 264 to rotate out of engagement with needle actuator 220 ( FIG. 60 ), and also allows needle actuator 220 to continue its distal displacement to retract patient needle 215 ( FIG. 61 ). At this stage, a different color or pattern, such as red, of status bar 258 is visible through status viewing port 208, indicating that device 200 has completed its operation.

[0055] As previously noted, contact between outer plunger 240 and spacer 226, as shown in FIGS. 62 and 63, is preferably damped to minimize impact forces. For underfilled syringes containing viscous fluids, the highest level of energy dissipation is desired, as outer spring 242 can be made stiffer to provide the desired dispense rate. For fully filled syringes containing low viscosity fluids, the lowest level of energy dissipation is desired, as outer spring 242 can be made less stiff to provide the desired dispense rate. Various methods can be used to adjust the level of damping, such as air damping or closed-cell foam damping.

[0056] As another method of damping impact forces, FIG. 64 shows an embodiment of a spacer 226 in which one or more axial interference ribs 272 are arranged circumferentially around the central column 230 of the spacer 226. In this embodiment, the outer plunger 240 must pass through the interference ribs 272, which provide frictional resistance to distal displacement of the outer plunger 240 relative to the spacer 226. The frictional force created by the interference between the interference ribs 272 and the outer plunger 240 is independent of plunger velocity. The frictional force preferably does not exceed the minimum dispensing spring load to avoid jamming the weaker spring. The interference can be adjusted to provide the desired level of frictional resistance. There can be various (axial and / or radial) sizings of the interference ribs 272 for different fluid viscosities. This could mean a custom or individually made spacer for each viscosity and fill level combination, or it could mean that depending on the number of springs required for a viscosity range, there could be multiple toothed positions that allow the spacer to be set to a specific position for a spring of a particular coefficient (the position is interference / damping tuned for that particular spring load / viscosity situation).

[0057] 65A-69, an actuator button mechanism 280 for activating the system 10 according to one embodiment of the present invention is shown. The actuator button mechanism 280 includes an actuator button 26, a button spring 284, and a needle actuator body 286. The needle actuator body 286 may be similar to the needle actuator bodies 96, 220 described above and may be configured to move within the housing 20 to transition the needle shuttle 102 or needle 28 between a retracted position and an extended position. As shown in FIG. 69, the actuator button 26 includes a user interface portion 288 for user interaction. The user interface portion 288 is preferably approximately 22 mm long and approximately 10 mm wide, although other suitable dimensions may be utilized. The actuator button 26 includes two pairs of lockout arms 290, 292 that interact with button contact surfaces 294, 296 on the needle actuator body 286 to prevent the needle actuator body 286 from swinging upward prior to device activation. As shown in Figure 65H, the overlap between the needle actuator body 286 and the housing 20 prevents premature actuation. Referring to Figure 66, the button spring 284 includes a first bearing surface 298 and a second bearing surface 300 spaced from the first bearing surface 298, as well as a cantilevered central spring arm 302 surrounded by a pair of outer arms 304 connected by the first bearing surface 298.

[0058] The actuation button mechanism 280 is configured to provide one or more of the following features, which are discussed in more detail below: unidirectional axial displacement or sliding of the actuator button 26; lateral movement of the actuator button 26 (raised and depressed positions), where the actuator button 26 remains depressed during the use position of the needle actuator body 286; and lockout of the actuator button 26 in a post-use position of the needle actuator body 286, where the button 26 is in the raised position and cannot be depressed by the user.

[0059] To activate the system 10 using the actuator button 26, the user first slides the user interface portion 288 in a first axial direction, shown as toward the right in FIGS. 65G and 65H. The user may be required to slide the user interface portion 288 approximately 10 mm or approximately 8 mm, although other suitable distances may be utilized. Moving the actuator button 26 axially moves the lockout arms 290, 292 to clear button contact surfaces 294, 296 on the needle actuator body 286, allowing the actuator button 26 to move from a raised position to a depressed position.

[0060] As the user slides the user interface portion 288 distally, the central spring arm 302 of the button spring 284 overcomes the spring arm 306 support surface on the housing 20, while the first and second support surfaces 298, 300 engage first and second support ramps 308, 310 on the housing 20. The force exerted on the button spring 284 is balanced through engagement with the spring arm support surface 306 and the first and second support ramps 308, 310 to provide smooth axial displacement or sliding of the actuator button 26.

[0061] 65H, when the actuator button 26 and button spring 284 reach the end of their axial sliding travel, the central spring arm 302 and first support surface 298 pass the ends of the respective stops 312, 314, preventing the actuator button 26 from returning to its initial position. Furthermore, once the actuator button 26 and button spring 284 reach the end of their axial sliding travel, the user engages the user interface portion 288 to move the actuator button 26 downward to its depressed position. The actuator button 26 may be depressed approximately 2 mm, and the minimum force required to depress the actuator button 26 is approximately 3 N, most preferably approximately 2.8 N, although other suitable distances and minimum forces may be utilized.

[0062] As shown in Figures 65A and 65B, when a user presses down on the user interface portion 288, the actuator button 26 rotates the needle actuator body 286 to release it, thereby allowing it to move from the pre-use position to the use position. As shown in Figure 65B, as the needle actuator body 286 moves to the use position, the lockout arms 290, 292 ride along the underside of the button contact surfaces 294, 296 to prevent the actuator button 26 from bouncing upward. After the medication is delivered, as shown in Figure 65C, as the needle actuator body 286 transitions from the use position to the post-use position, the lockout arms 290, 292 disengage from the button contact surfaces 294, 296, allowing the actuator button 26 to bounce upward under the influence of the button spring 284. 65D, once the needle actuator body 286 has fully transitioned to the post-use position, the actuator button 26 has completed its movement from the depressed position to the raised position due to the biasing force of the button spring 284. When the needle actuator body 286 is in the post-use position, the spring arm 316 on the needle actuator body 286 engages the actuator button 26, preventing it from moving to the depressed position, while axial movement is still limited by the engagement of the spring arm 302 with the stops 312, 314. Thus, the actuator button 26 is locked after medication delivery is complete, providing a clear indication between a used and an unused system.

[0063] Additionally, if the user depresses the actuator button 26 while medication is being dispensed, proper administration and needle retraction will still be completed, but the actuator button 26 will not spring back to the raised position until the button 26 is released.

[0064] In one embodiment, the button spring 284 is made of plastic. The button spring 284 may alternatively be a stamped metal spring, although any other suitable metal may be utilized.

[0065] 68A-68G, rather than providing a separate actuator button 26 and button spring 284, the spring may be integral with the button 26. More specifically, an actuator button 320 according to a further embodiment of the present invention includes an integral spring arm 322. The actuator button 320 also includes a lockout arm 324, a retention arm 326, and a rear pivot 328. As shown in FIGS. 68D and 68E, the spring arm 322 engages a prong 330 within the top portion 22 of the housing 20. During transition of the system 10 from the pre-use position to the use position, the spring arm 322 slides past a detent on the prong 330 to provide an axial spring force. The distal end of the spring arm 322 engages a portion of the top portion 22 of the housing 20 to provide a vertical spring force as the spring arm 322 deflects. The actuator button 320 is configured for smooth movement between the sliding and lowering movements of the button 320, similar to the operation of button 26 described above, even though two separate movements occur. During the transition between the pre-use and use positions, the button 320 pivots about a rear pivot 328, with a retaining arm 326 engaging a portion of the needle actuator body 286 to maintain the button 320 in a depressed position until the end-of-dose position is reached, in a manner similar to actuator button 26. The lockout arm 324 is biased inward to engage a portion of the needle actuator body 286 as the needle actuator body 286 moves to the end-of-dose position, thereby preventing further movement of the actuator button 320, in a manner similar to actuator button 26 described above.

[0066] Aspects of the present invention offer improvements over previous button designs. For example, the activation button mechanism 280 provides multiple surfaces to hold the needle actuator body 286 in place against the needle actuator spring 106 prior to activation, thereby reducing the likelihood of premature activation during a drop impact. The activation button mechanism 280 physically prevents the needle actuator body 286 from moving prior to activation by holding it in a tilted (locked) position so that no surfaces have room to separate and pre-activate.

[0067] Additionally, the button slide force of the activation button mechanism 280 is more precisely controlled by utilizing a bending arm rather than using a simple bump detent. This allows for a longer sliding stroke of the button 26 with better force control, resulting in a more ergonomically effective design. Additionally, the activation button mechanism 280 causes the button 26 to spring back to its original position at the end of the injection, providing the user with additional visual, audible, and tactile indication that medication delivery is complete.

[0068] According to one embodiment, the fluid delivery volume of system 10 is determined by the end position of the plunger relative to its position inside the housing, regardless of the actual fill volume, container inner diameter, and stopper starting position and length. Because the tolerances for the above factors can be significant, dosing accuracy variations can be substantial. Embodiments of the present invention allow for some or all of these tolerances to be removed from the dosing equation, resulting in a more accurate and less variable injection volume of medication.

[0069] 70A-70G, a spacer assembly 400 for use with a drive assembly according to one embodiment of the present invention is shown.

[0070] Elements in the tolerance chain for the stopper spacer assembly 400 include the thickness (A) of the flange 402 of the inner plunger 404, the internal length (B) between the internal proximal end 408 of the outer plunger 406 and the internal shoulder 410, and the initial offset distance (C1) between the internal plunger flange 402 and the internal proximal end 408 of the outer plunger. This initial offset distance (C1) is preferably greater than the clearance distance (C2) between the outer plunger 406 and the proximal end of the drug barrel 412. The tolerance chain for the stopper spacer assembly 400 also includes the internal barrel diameter (D). When assembled, the stopper spacer 414 and outer plunger 406 are unique for a given drug volume.

[0071] 70B-70G illustrate the operation of the stopper-spacer assembly 400. As shown in FIG. 70B, when the system is actuated, both the inner plunger 404 and the outer plunger 406 are released. The outer spring 416 pushes the outer plunger 406 into the barrel 412, compressing the damping material 418 and the inner spring 420. The stopper 422 does not yet move relative to the barrel 412 due to the drug fluid.

[0072] 70C, the outer spring 416 then distally displaces the outer plunger 406 and barrel 412, opening a valve (not shown) at the distal end of the barrel 412 which establishes fluid communication with the needle (not shown). Due to the incompressibility of the liquid medication, the stopper 422 cannot be displaced relative to the barrel 412 until the valve is opened, establishing a fluid path to the patient needle.

[0073] Subsequently, inner spring 420 displaces inner plunger 404, stopper spacer 414, and stopper 422 to dispense fluid, as shown in Figures 70D and 70E.

[0074] Figure 70F shows the end of drug delivery when the proximal flange 402 of the inner plunger 404 contacts the internal shoulder 410 of the outer plunger 406, thereby ceasing displacement of the inner plunger 404 (as well as the stopper spacer 414 and stopper 422) relative to the drug barrel 212 and stopping the flow of drug.

[0075] According to one embodiment, as shown in FIG. 70G, cessation of displacement of the inner plunger 404 relative to the drug barrel 412 activates an end-of-dose indicator of the system.

[0076] 71 and 72, the collapsible spacer assembly 430 includes a front spacer portion 432 secured to a stopper 434, an inner plunger 436, a rear spacer portion 438, and a rotational shuttle 440. The inner plunger 436 can translate relative to the front spacer portion 432 but cannot rotate relative to it. Similarly, the rear spacer portion 438 can also move axially relative to the front spacer portion 432 but cannot rotate relative to it. As will be explained in more detail below, the rotational shuttle 440 first rotates and then translates.

[0077] According to one embodiment, the front spacer portion 432 is securely attached to the stopper 434. Those skilled in the art will appreciate that many methods may be used to secure the front spacer portion 432 to the stopper 434, such as adhesives, mechanical fasteners, or any other suitable mechanism. The front spacer portion 432 preferably includes threads that engage threaded holes in the stopper 434.

[0078] When the stopper spacer assembly 430 is threaded onto the stopper 434, an axial load is applied through an access opening 442 in the rear spacer portion 438. This force can be used to push the stopper 434 forward, applying pressure to the fluid drug. This pressure causes the front (distal) face of the stopper 434 to flex proximally, exerting pressure and pushing back against the rear spacer portion 438, causing the rotating shuttle to rotate to its "as-assembled" state. In other words, when the drug barrel is filled with drug and the system's plunger applies an axial force to the drug via the spacer assembly 430, the distal face of the stopper 434 is deformed by the drug pressure. During drug delivery, pressure is applied by the drive assembly (via the plunger) to the rear spacer portion 438, which in turn applies a rotational torque to the rotating shaft 440 via the torsional surface 444 of the rear spacer portion 438. However, stopper deformation by the drug exerts a rearward or proximal force on inner plunger 436 which prevents rotation of rotating shuttle 440 .

[0079] According to one embodiment, the axial reaction load on the inner plunger 436 can be increased by increasing the length of the inner plunger 436 .

[0080] Once drug delivery is complete, as shown in FIG. 73 , pressure on the stopper 434 is reduced, thereby allowing the distal end of the inner plunger 436 to displace distally. This distal displacement allows the rotating shuttle 440 to rotate. A sustained axial force applied by the drive assembly rotates and displaces the rotating shuttle 440 distally due to the interaction of the torsion surface 444 on the rear spacer portion 438 with the corresponding cam surface arm 446 on the rotating shuttle 440. According to one embodiment, this final movement of the rotating shuttle 440 causes the drive assembly to cause needle retraction.

[0081] 74 and 75, a limiting member 452 according to one embodiment of the present invention is positioned with the drive assembly. The limiting member 452 influences the timing of the final displacement of the needle actuator body 96, 220 after completion of drug administration. The limiting member 452 floats rather than rotates about a fixed post. When the plunger is displaced distally enough relative to the gap to align with the limiting member 452 (as shown in FIGS. 74 and 75), the limiting member 452 is displaced laterally toward the gap due to the force of the spring on the needle actuator 96, 220 and the sloped surface 454 (best shown in FIG. 75) on the rear of the arm of the limiting member 174 that engages the needle actuator body. Once the limiting member no longer holds the needle actuator body 96, 220, the needle actuator body 96, 220 is free to complete its axial movement to the post-use position. Additionally, as shown in FIG. 75, the restrictor member 452 is biased onto the rear of the barrel portion of the container 14, which minimizes tolerance chains of the various components and improves dose accuracy.

[0082] 76-78, there is shown a spacer assembly 460 according to a further embodiment of the present invention. The spacer assembly 460 shown in Figures 76-78 allows for elimination of the effects of increasing manufacturing tolerances through adjustment of the spacer assembly, thus allowing each system to inject the same amount of medication.

[0083] 77, spacer assembly 460 includes a stopper 462 and a stopper spacer 464. Stopper spacer 464 includes a fixed spacer piece or spacer 466 fixedly connected to stopper 462 and an adjustable spacer piece or spacer 468 rotationally displaceable in one direction relative to fixed spacer 466.

[0084] Those skilled in the art will appreciate that many methods may be used to secure fixed spacer 466 to stopper 462, such as, for example, adhesives, mechanical fasteners, or any other suitable mechanism. Fixed spacer 466 preferably includes one or more external threads that engage one or more threads on stopper 462. According to one embodiment, adjustable spacer 468 has a distal stem with external threads 470. Distal stem threads 470 engage internal threads 472 (best shown in FIG. 78 ) on fixed spacer 466 to rotationally control the axial displacement of adjustable spacer 468 relative to fixed spacer 466.

[0085] 76 and 77, fixed spacer 466 includes radially spaced detents 474, and adjustable spacer 468 includes spring detent arms 476, the free ends of which engage selected ones of detents 474 to prevent rotation and axial displacement of adjustable spacer 468 toward fixed spacer 466. The free ends of spring detent arms 476 are shaped to allow rotation and proximal axial displacement of adjustable spacer 468 past detents 474 in one direction and away from fixed spacer 466.

[0086] The adjustable spacer 468 can be adjusted relative to the fixed spacer 466 to provide a constant axial length of the stopper assembly 460 despite variations in stopper and container dimensions.

[0087] As shown in FIG. 78 , once the container is filled, an axial load, such as that which would be experienced when installed in the system 10, 200, can be applied to the adjustable spacer 468 (and thus the fixed spacer 466 and stopper 462). When the axial load is applied, the adjustable spacer 468 is retracted proximally to ensure a consistent gap 478 between the proximal end of the drug barrel 480 and the proximal face of the adjustable spacer, thereby compensating for variations in drug barrel glass and the compressibility of entrapped air. In other words, the spacer assembly 460 allows the adjustable spacer 468 to have a predetermined set position relative to the container 14, regardless of variations in the container 14 and stopper length. Thus, the starting position of the spacer assembly 460 is a predetermined distance from the container 14, and the ending position of the spacer assembly 460 is also a predetermined distance from the container 14, so that the stroke of the stopper 462 is determined by the effective length of the plungers 52, 54 of the drive assembly 12.

[0088] 79 and 80 , a base column 482 and cap 484 of a self-adjusting spacer 486 according to one aspect of the present invention are shown. The base column 482 includes a base portion 488 and an axially extending column 490. According to one embodiment, the base column 482 includes a plurality of post-like protrusions 491, each having a plurality of ratchet teeth 492 disposed on a proximal portion thereof. A locking barb 493 is disposed at the proximal end of each of the plurality of ratchet teeth 492. The cap 484 is hollow, and a distal end of the cap 484 includes one or more axial springs 494. According to one aspect, the axial springs 494 are curved cantilevered arms formed during molding of the cap 484. According to another aspect, a separate biasing member, such as a compression spring, may be used with the self-adjusting spacer 486. When assembled with base column 482, spring 494 engages base portion 488 to maintain an initial spacing between base column 482 and cap 484. According to one embodiment, spring 494 is omitted. Cap 484 also includes a plurality of flexible cantilevered arms or tabs 496, each having a free proximal portion including a plurality of internal ratchet teeth 497. The proximal end of each flexible tab 496 includes a foot 498.

[0089] 81B shows a self-adjusting spacer cap positioned within a proximal recess of a stopper 494 at the proximal portion of a drug barrel. A base column 482 is assembled within the hollow cap 484 with the base portion 482 engaging the stopper 494 and the feet 498 positioned outside the proximal end of the barrel.

[0090] In operation, as shown in Figures 81A and 81B, the cap 484 is positioned distally relative to the base column 482 (and stopper 494 and barrel) until the proximal end of the cap 484 is flush with the end of the drug barrel. This action engages and displaces the foot 498 radially inward with the interior surface of the barrel, thereby forcing the ratchet teeth 492 into locking engagement with the ratchet teeth 497. The locking barb 493, the engagement of the ratchet teeth 492 and 497, and the engagement of the foot 498 with the interior surface of the barrel prevent displacement of the cap 484 relative to the base column 482. Thus, the automatically adjusting spacer 486 can accommodate differences in stopper, barrel diameter, and drug fill volume to automatically provide a support surface flush with the proximal end of the drug barrel.

[0091] One embodiment of the present invention is a spacer assembly 486 that is positioned in the system against the stopper in the container. The spacer design is such that its effective length can be adjusted to allow for precise dispensing of a drug. The length adjustment is intended to compensate for manufacturing tolerances in the container, fill volume, and especially stopper length, which can ultimately account for one-third of the variability in the dose delivered using a non-adjustable spacer. The spacer length can be adjusted through several techniques, depending on the specific embodiment. The spacer length can be self-adjusting based on its position to the rear of the container, it can be adjusted by assembly equipment at the time of final assembly of the main container to the subassembly, or it can be made as an integral part of the stopper and adjusted as a subassembly prior to filling. The adjustable spacer 486 allows for a more precise amount of fluid to be injected compared to a non-adjustable spacer.

[0092] 82-87, a drive assembly 500 for a drug delivery system according to one embodiment of the present invention is shown. Drive assembly 500 includes an actuation button 506, a reservoir 508, a needle actuator assembly 510, an actuation release or flipper 512, a lead screw 514, and a plunger 516. The lead screw includes a drum portion 518 with radially protruding external vanes 520 and a threaded portion 522, as best shown in FIGS. 84 and 85 and as will be described in more detail below. Prior to actuation, one end 513 of actuation release 512 engages one of the vanes 520 to prevent rotation of lead screw 514, as best shown in FIGS. 83 and 86.

[0093] According to one embodiment, as shown in FIGS. 84-86 , a threaded portion 522 of the lead screw 514 engages with internal threads of a nut 524 connected to a plunger 516. According to another embodiment, the nut and its internal threads are integrally formed with the plunger as a unitary structure. Additionally, a constant force spring 526 is received within the drum portion 518 to rotationally bias the lead screw 514. According to one embodiment, the spring 526 is secured to the base cover 504. According to another embodiment, as shown in FIGS. 84-86 , a drive assembly housing 528 is disposed within the system, and the spring 526 is secured to the power pack housing 528.

[0094] Unlike helical springs, such as compression springs, which have a force profile proportional to their displacement, constant force springs, such as constant force spring 526, maintain a relatively flat or uniform force profile over a long operating length. A uniform force profile advantageously provides an injection force proportional to the spring force. This provides a flat or uniform injection force and, therefore, a substantially constant injection rate for the medicament. While spring 526 is shown in FIG. 86 as having only two turns of material, one skilled in the art will understand that fewer or more turns may be used. Preferably, an assembler winds spring 526 when drive assembly 500 is assembled, and spring 526 is stored in the wound position until actuation.

[0095] Upon actuation of the system, the needle actuator assembly 510 is released and displaces axially (to the right in FIGS. 82-85) from a pre-use position to a post-use position under the influence of a biasing member 530 (best shown in FIG. 83). During this displacement, the needle actuator assembly 510 abuts the second end 532 of the actuation release 512, causing the release 512 to rotate counterclockwise, as shown in FIG. 87. This counterclockwise rotation of the actuation release 512 releases its first end 513 from engagement with the vanes 520. Following disengagement of the first end 513 from the vanes 520, the spring 526 unwinds and rotates the lead screw 514, which, in combination with the nut 524, advances the plunger 514 to dispense the medicament.

[0096] As the lead screw 514 rotates, the rotation of the drum portion 518 and vanes 520 is visible through a window 534 in the housing. This window 534 indicates the progress of the screw in a more obvious manner than viewing the linear movement of the stopper 536 within the container 508. In fact, this rotational movement is many times more sensitive than linear movement. Those skilled in the art will understand that the exact amount of benefit or increase will depend on the pitch of the threaded portion 522 of the lead screw 514, the diameter of the drum portion 518, and the number of vanes 520 on the drum portion 518.

[0097] 88-93, a drive assembly 600 for a drug delivery system according to a further embodiment of the present invention is shown. The drive assembly 600 serves to store the mechanical energy of a spring and activate it when actuated. The drive assembly 600 includes a drug barrel 601, a stopper 602 slidably disposed within the barrel 601, a first valve plunger 603, a second valve plunger 604, a first rotating nut 605, and a second rotating nut 606. The drive assembly 600 also includes a rotary indicator 607, a locking element 608, a constant force spring 609 disposed within the rotary indicator 607, and an actuation release or flipper 610. The drive assembly 600 is at least partially disposed within a housing 611, which can be assembled within the drug delivery system.

[0098] A constant force spring 609 is housed within the drum portion 616 of the rotary indicator 607 between the housing 611 and the rotary indicator 607. The inactive state of the drive assembly is such that energy is applied by releasing the spring 609 and this energy is geometrically utilized by the housing 611, the rotary indicator 607, and the actuation release 610. When the drive assembly 600 is deactivated, the spring recoils, converting mechanical energy into rotational motion of the rotary indicator.

[0099] The telescoping multi-part plunger is oriented along a force axis between the medication barrel 601 and the rotary indicator 607. The rotary indicator 607 features a threaded shaft 618. According to one embodiment, the threads are double-lead and square or rectangular in nature. The multi-part telescoping plunger includes a two-part threaded nut (first rotary nut 605 and second rotary nut 606) and a two-part plunger (first valve plunger 603 and second valve plunger 604). The second rotary nut 606 is a threaded shaft that mates with the rotary indicator 607 and the first rotary nut 605 and features matching threads (female and male threads, respectively) on its inner and outer surfaces to mate with them. The second rotating nut 606 also has a circular collar 620 (best seen in FIG. 92) on its proximal end that seats on the second valve plunger 604. The second rotating nut 606 is free to rotate along the force axis. The first rotating nut 605 is also a threaded shaft that features threads on its inner diameter that correspond to the external threads of the second rotating nut 606 to mate with the second rotating nut 606.

[0100] According to one embodiment, the first rotating nut 605 has a hexagonal collar on one end that is press-fit onto the first valve plunger 603 to fixedly connect the first valve plunger 603 to the first rotating nut 605. In the drive assembly 600, the first rotating nut is not free to rotate and only translates when the power module subassembly is actuated.

[0101] The second valve plunger 604 is a hollow cylindrical component including a small collar 622 on its distal end, a large collar 624 on its proximal end, and an extended L-shaped arm 626 (best shown in FIG. 93 ) projecting from the large collar 624. According to one embodiment, the small collar 622 is discontinuous and features four leaf cantilever arms or leaf springs 623 that allow the collar to flex and mate with the first valve plunger 603. The inner surface of the second valve plunger 604 has a relief groove along its length and terminates at its proximal end in a ledge 628 that projects radially inward of the large collar 624. The ledge 628 engages the second rotating nut 606 within the telescoping assembly.

[0102] First valve plunger 603 is a hollow cylindrical component that attaches to stopper 602 and mates with second valve plunger 604. More specifically, first valve plunger 603 features a cylindrical protrusion 630 on its distal end to mate with stopper 602. According to one embodiment, as best shown in FIG. 89 , four through grooves 632 are located on the proximal quadrant of first valve plunger 603 to mate with leaf springs or arms 623 and small collar portion 622 of second valve plunger 604. Both first valve plunger 603 and second valve plunger 604 are free to slide.

[0103] Nesting is achieved when the constant force spring 609 recoils and the rotary indicator 607 begins to rotate. The threaded connection between the rotary indicator 607 and the second rotating nut 606 causes the second rotating nut 606 to rotate. However, because the second rotating nut 606 is threaded onto the first rotating nut 605, the first rotating nut 605 is unable to rotate and experiences resistance to distal translation due to pressure created by the drug within the barrel 601, causing the second rotating nut 606 to displace proximally and bottom out on the radially inwardly projecting ledge 628 of the second valve plunger. The second valve plunger 604 is prevented from displacing proximally by the housing 611. Subsequently, as rotation of the rotary indicator 607 continues, the second rotary nut 606 is threadedly engaged with the first rotary nut 605 (which cannot rotate), causing the first rotary nut 605 to translate distally, pushing the first valve plunger 603 (and stopper 602) and dispensing the drug from the barrel 601.

[0104] The first valve plunger 603 is displaced distally relative to the second valve plunger 604 until small collar sections 622 (located on the distal ends of the leaf springs or arms 623 of the second valve plunger 604, respectively) engage corresponding proximal ends of grooves 632 of the first valve plunger 603. This locks the relative orientation of the first and second valve plungers 603, 604, and as rotation of the rotary indicator 607 continues, both valve plungers translate distally while simultaneously pushing the second rotating nut (due to its proximal engagement with ledge 624).

[0105] The initial and final positions of the telescopic plunger, and therefore the drug dose, are controlled by the rectangular thread profile of the threaded shaft 618 of the rotary indicator 607, the threaded shaft on the drum portion 616 of the rotary indicator 607, and a shoulder pin that acts as the locking element 608. According to one embodiment, the threaded shaft on the drum portion 616 of the rotary indicator 607 is single lead and the remaining components in the telescopic chain have double lead threads, so that the axial travel of the other threaded components is twice the axial travel of the lock 608 for the rotary indicator.

[0106] According to one embodiment, lock 608 is cylindrical and features a hemispherical tip on one end and a cylindrical collar on the other end. Threads on the exterior of rotary indicator drum portion 616, along with grooves and undercuts 636 in the bottom of housing 611, trap lock 608 in place and allow it to slide parallel to the force axis. Thus, when spring 609 is released and rotary indicator 607 rotates, lock 608 also translates, creating a positive stop when the distal end of the threads on the exterior of rotary indicator drum portion 616 is reached.

[0107] One advantage of embodiments of the drive assembly 600 includes the use of a constant force spring 609, whose mechanical energy is converted into a substantially constant linear force on the drug within the barrel 601, which in turn creates a uniform drug delivery rate. Another advantage is the use of telescoping plungers driven by thread forms, which allows the drive assembly to provide up to 0.75 inches (1.905 cm) of inline space savings compared to other plunger designs. Additionally, the drive assembly provides a controlled drug dose through initial and final mechanical constraint within the same component.

[0108] As previously noted, other drug delivery systems utilize compression coil springs that exert a maximum force upon actuation, which gradually weakens as the spring expands. The weakening force on the plunger results in inconsistent drug delivery times and drug ejection pressures. By using a constant force spring, the force applied to the plunger is constant throughout administration. Furthermore, the distance the coil spring must travel, in addition to the static plunger length that requires translation inside the drug container, can create a long assembly. In contrast, in embodiments of the present invention, the constant force spring is radially contained and does not require any additional space before or after actuation. Furthermore, the telescoping plunger aspect allows the plunger length to be significantly reduced compared to the static plunger length.

[0109] Previous drug delivery systems have erratic dose accuracy performance because the mechanical components that enable drug delivery create geometric dependencies by being based on a reservoir that cannot be made to tight tolerances. Some embodiments of the present invention provide control over the start and end times of the translating plunger through the use of a thread profile in the rotary indicator and a constant force spring.

[0110] The drive assembly creates a space-saving geometry along with well-controlled time, volume, and pressure for the drug delivery device, which translates into a more attractive, compact, and precise drug delivery device.

[0111] Some embodiments of the drive assembly implement three rotating threaded shafts, resulting in a linear space savings of approximately 0.75 inches (1.905 cm). In other embodiments, a similar concept may be employed using two rotating threaded shafts, resulting in a space savings of approximately 0.5 inches (1.27 cm). Some embodiments of the present invention convert the rotational energy of a constant force spring into translational force motion of a plunger.

[0112] 94-100, a spacer assembly 660 according to a further embodiment of the present invention is shown. The spacer assembly 660 is similar to the spacer assembly 460 described above and shown in FIGS. 76-78, operates in a similar manner, and provides similar advantages. The spacer assembly 660 includes a fixed spacer 666 and an adjustable spacer 668. The fixed spacer 666 is configured to be received by the stopper 462, with a lug 670 engaging the stopper 462 to secure the fixed spacer 666 within the stopper 462, although other suitable securing mechanisms, such as threads, may be utilized. The fixed spacer 666 includes internal threads 672 that receive the external threads 678 of the adjustable spacer 668. The fixed spacer 666 includes a plurality of detents 674 positioned on a helical portion of the fixed spacer 666. The adjustable spacer 668 includes a spring detent arm 676 that engages one of the detents 674 to prevent rotation and axial displacement of the adjustable spacer 668 relative to the fixed spacer 666. The spring detent arm 676 is shaped and configured to pass over the detents 674 in one direction, allowing rotation and axial displacement of the adjustable spacer 668 away from the fixed spacer 666. The adjustable spacer 668 may be initially secured to the fixed spacer 666 via the screws 672, 678 by applying a force to the top of the spring detent arm 676 that urges the spring detent arm 676 away from the detent 674, allowing the spacers 666, 668 to be secured together. Thus, the adjustable spacer can be freely rotated in one axial direction to adjust the length of the spacer assembly 660, in a manner similar to that described above in connection with the spacer assembly 460.

[0113] Referring again to FIGS. 94-100 , the spacer assembly 660 further includes a shim 680 configured to be received and secured to the adjustable spacer 668. Rather than providing multiple sizes of adjustable spacers 468, 668, multiple shim 680 sizes may be provided to accommodate multiple different fill volumes within the container 14. The shim 680 may be secured to the adjustable spacer 668 via a connector 682 extending from the shim 680 that is received by the adjustable spacer 668 using a snap fit, although other suitable securing mechanisms may be utilized. A central portion 684 of the fixed spacer 666 is configured to engage while the adjustable spacer 668 is rotated relative to the fixed spacer 668 to prevent the fixed spacer 666 from rotating with the adjustable spacer 268. The central portion 684 of the fixed spacer 666 is accessible through an opening in the shim 680.

[0114] Elements of one disclosed embodiment may be combined with elements of one or more other disclosed embodiments, all of which are contemplated as falling within the scope of the present invention.

[0115] While this disclosure has been described as having an exemplary design, the disclosure can be further modified within the spirit and scope of the disclosure. Accordingly, this application is intended to cover any variations, uses, or adaptations of the disclosure using its general principles. Further, this application is intended to cover such departures from the disclosure as come within known or customary practice in the art to which this disclosure pertains and fall within the limits set forth in the appended claims.

Claims

1. 1. A drug delivery system for injecting a medicament, comprising: a barrel configured to contain the medicament; a stopper movably disposed within the barrel; 1. A drive assembly comprising: a first plunger coupled to the stopper; a second plunger telescopically coupled to the first plunger; a rotary indicator coupled to the first and second plungers, the rotary indicator configured to cause axial movement of the first and second plungers upon rotation of the rotary indicator; a drive assembly coupled to the rotary display and including a constant force spring for driving the rotary display to rotate; A drug delivery system comprising:

2. The system of claim 1 , wherein the rotary indicator includes a threaded shaft coupled to the first and second plungers.

3. The system of claim 1 , wherein the first plunger includes a hollow cylindrical body.

4. The system of claim 3 , wherein the first plunger includes a protrusion at a distal end of the hollow cylindrical body that mates with the stopper.

5. The system of claim 1 , wherein the second plunger comprises a hollow cylindrical body.

6. The system of claim 5 , wherein the second plunger includes a first collar at a distal end of the hollow cylindrical body and a second collar at a proximal end of the cylindrical body.

7. The system of claim 6 , wherein the first plunger is configured to be displaced distally relative to the second plunger until the first collar engages the first plunger.

8. The system of claim 1 , wherein the first plunger includes a plurality of slots configured to mate with a plurality of arms of the second plunger.

9. The system of claim 1 , wherein the constant force spring rebounds to drive rotation of the rotary display.

10. The system of claim 1 , wherein the drive assembly further comprises a lock coupled to the rotary indicator and configured to limit rotation of the rotary indicator.

11. The system of claim 1 , further comprising an actuation release configured to actuate the constant force spring to drive rotation of the rotary indicator.

12. The system of claim 1 , wherein the rotating indicator includes a drum portion defining a threaded outer surface.

13. The system of claim 12 , wherein the upper force spring is housed in the drum portion.

14. The system of claim 12 , further comprising a lock configured to engage the drum portion to limit rotation of the rotary indicator.

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