Drug delivery system for injection of a medicament

Abstract

A drug delivery system for injecting a medicament, comprising: a container configured to receive a medicament; a drive assembly configured to expel the medicament from the container upon actuation; a needle for injecting the medicament into a patient; a needle actuator assembly comprising a movable portion biased by a biasing member and configured to move the needle between a pre-use position, a use position for delivering the medicament to the patient, and a post-use position after completion of delivery of the medicament; and a tube in fluid communication with the container and the needle, the tube comprising an expandable portion having an expanded state and a non-expanded state, wherein the expandable portion is configured to be in the expanded state upon actuation of the drive assembly and in the non-expanded state when the needle is in the post-use position.

Description

[0001] This application is a divisional application of Chinese invention patent application No. 201880075628.4, which is entitled "Dose End Detection for Drug Delivery System" and has entered the Chinese national phase with the international application PCT / US2018 / 055879 filed on October 15, 2018.

[0002] Cross-references to related applications

[0003] This application claims priority to U.S. Provisional Application Serial No. 62 / 572,722, filed October 16, 2017, entitled “Drug-of-Dose Detection for Drug Delivery System,” the entire disclosure of which is incorporated herein by reference. Technical Field

[0004] This disclosure generally relates to a syringe device and method for delivering fluid into a patient via injection, and more particularly to a dose end detection device for preventing needle actuator movement during fluid delivery and for controlling needle withdrawal from the patient at the end of the dose. Background Technology

[0005] Various types of automated injection devices have been developed to allow drug solutions and other liquid therapeutic preparations to be administered or self-injected by untrained personnel. Typically, these devices consist of a reservoir pre-filled with the liquid therapeutic preparation and some type of automated needle injection mechanism that can be triggered by the user. When the volume of the fluid or drug to be administered is typically less than a certain volume (e.g., 1 mL), an automated injector is usually used, with an injection time typically around 10 to 15 seconds. When the volume of the fluid or drug to be administered is greater than 1 mL, the injection time typically becomes longer, making it difficult for the patient to maintain contact between the device and the target area of ​​the patient's skin. Furthermore, as the volume of the drug to be administered increases, it becomes desirable to increase the time period used for injection. The traditional method of slowly injecting drugs into a patient is to initiate an intravenous infusion and slowly inject the drug into the patient. This procedure is typically performed in a hospital or outpatient setting.

[0006] Some devices allow for self-injection in a home setting and are capable of gradually injecting liquid therapeutic preparations into the patient's skin. In some cases, these devices are small enough (both in height and overall size) to be "worn" by the patient while the liquid therapeutic preparation is being infused into the body. These devices typically include a pump or other type of discharge mechanism to force the liquid therapeutic preparation out of the reservoir and into the injection needle. Such devices often also include valves or flow control mechanisms to initiate the flow of the liquid therapeutic preparation at the appropriate time and a trigger mechanism to initiate the injection. Summary of the Invention

[0007] According to one aspect of the invention, a drug delivery system for injecting a drug includes: a container configured to deliver the drug; a drive assembly configured, when actuated, to displace the drug from the container; a needle for injecting the drug into a patient; a needle actuator assembly including a movable portion biased by a biasing member and configured to move the needle between a pre-use position, a use position for delivering the drug to a patient, and a post-use position after drug delivery; and a tube in fluid communication with the container and the needle, the tube including an expandable portion having an expanded state and a non-expanded state, wherein the expandable portion is configured to be in an expanded state when the drive assembly is actuated and in a non-expanded state when the needle is in the post-use position.

[0008] When the needle is in the pre-use position, the expandable portion of the tube is in a non-expanded state. When the expandable portion of the tube is in the expanded state, the movable portion of the needle actuator assembly engages with the expandable portion of the tube. The expandable portion of the tube is configured to be in the expanded state by pressure within the container caused by actuation of the drive assembly. When the pressure within the container caused by actuation of the drive assembly decreases due to a lack of medication within the container, the expandable portion of the tube is configured to change from the expanded state to the non-expanded state. When the tube enters the non-expanded state, the engagement between the needle actuator assembly and the tube is released, thereby allowing the needle actuator assembly to move and retract the needle.

[0009] The drug delivery system may further include a housing that surrounds at least a portion of the container, drive assembly, needle, needle actuator assembly, and tube. When in the use position, at least a portion of the needle extends from the housing.

[0010] According to one design, the tube can be associated via a slot provided in the top portion of the needle actuator in order to hold the tube in place.

[0011] Using the dosing end device of the present invention allows the stopper or plunger component to bottom out inside the container and automatically withdraws the needle from the patient after the dose is finished.

[0012] According to another embodiment of the present invention, a drug delivery system for injecting a drug includes: a container configured to deliver a drug; and a drive assembly configured to displace the drug from the container upon actuation. The system further includes: a needle for injecting the drug into a patient; a needle actuator assembly including a movable portion biased by a biasing member and configured to move the needle between a pre-use position, a use position for delivering the drug to a patient, and a post-use position after drug delivery; and a dose end detection assembly that prevents the needle actuator from moving during drug delivery.

[0013] In some configurations, the dose end detection component includes an expandable portion that expands during drug delivery and collapses at the end of the dose to allow needle movement.

[0014] In other configurations, the expandable portion collapses due to a pressure drop in the fluid path defined between the container and the needle. Attached Figure Description

[0015] The above and other features and advantages of this disclosure, as well as the ways in which they are implemented, will become more apparent and the disclosure itself will be better understood by referring to the following description of examples of this disclosure taken in conjunction with the accompanying drawings, wherein:

[0016] Figure 1 This is a perspective view of a drug delivery system according to one aspect of the present invention.

[0017] Figure 2 According to one aspect of the present invention Figure 1 A perspective cross-sectional view of a drug delivery system.

[0018] Figure 3 According to one aspect of the present invention Figure 1 A front cross-sectional view of a drug delivery system.

[0019] Figure 4 According to one aspect of the present invention Figure 1 A top view of the drug delivery system, showing the top portion of the housing removed and the drug delivery system in its pre-use position.

[0020] Figure 5 According to one aspect of the present invention Figure 1 The top cross-sectional view of the drug delivery system shows the drug delivery system in its pre-use position.

[0021] Figure 6 According to one aspect of the present invention Figure 1 A front cross-sectional view of the drug delivery system, showing the drug delivery system in its pre-use position.

[0022] Figure 7 According to one aspect of the present invention Figure 1 A top view of the drug delivery system, showing the top portion of the housing removed and the drug delivery system in the initial actuation position.

[0023] Figure 8 According to one aspect of the present invention Figure 1 The image shows a top-view cross-sectional view of the drug delivery system in its initial actuation position.

[0024] Figure 9According to one aspect of the present invention Figure 1 A front cross-sectional view of the drug delivery system, showing the drug delivery system in the initial actuation position.

[0025] Figure 10 According to one aspect of the present invention Figure 1 A top view of the drug delivery system, showing the top portion of the housing removed and the drug delivery system in its use position.

[0026] Figure 11 According to one aspect of the present invention Figure 1 The image shows a top-view cross-sectional view of the drug delivery system, indicating the system in its place of use.

[0027] Figure 12 According to one aspect of the present invention Figure 1 A front cross-sectional view of the drug delivery system, showing the drug delivery system in the usage position.

[0028] Figure 13 According to one aspect of the present invention Figure 1 A top view of the drug delivery system, showing the top portion of the housing removed and the drug delivery system in its post-use position.

[0029] Figure 14 According to one aspect of the present invention Figure 1 The image shows a top-view cross-sectional view of the drug delivery system in its post-use position.

[0030] Figure 15A According to one aspect of the present invention Figure 1 A front cross-sectional view of the drug delivery system, showing the drug delivery system in its post-use position.

[0031] Figure 15B According to one aspect of the present invention Figure 1 A front cross-sectional view of a drug delivery system, showing the pad in the pre-use position of the drug delivery system.

[0032] Figure 15C According to one aspect of the present invention Figure 1 A perspective cross-sectional view of a drug delivery system, showing the pad in the pre-use position.

[0033] Figure 15D According to one aspect of the present invention Figure 1 A perspective cross-sectional view of a drug delivery system, showing the pad in the pre-use position.

[0034] Figure 16 According to one aspect of the present invention Figure 1 A partial cross-sectional view of a drug delivery system, showing the valve assembly.

[0035] Figure 17 This is a top view of a drug delivery system including a dose end detection device according to one aspect of the invention, wherein the top portion of the housing is removed and the drug delivery system is in the pre-use position.

[0036] Figure 18 yes Figure 17 A top view of the drug delivery system and dose end detection device, in which some components of the drug delivery system have been removed.

[0037] Figure 19A It is in an uninflated state according to one aspect of the invention. Figure 17 A perspective view of the dose-controlled detection component.

[0038] Figure 19B It is in an inflated state according to one aspect of the invention. Figure 17 A perspective view of the dose-controlled detection component.

[0039] Throughout these views, corresponding reference numerals denote corresponding parts. The examples described herein illustrate exemplary aspects of this disclosure, and such examples should not be construed as limiting the scope of this disclosure in any way. Detailed Implementation

[0040] The following description is provided to enable those skilled in the art to make and use the embodiments intended for carrying out the invention. However, various modifications, equivalents, variations, and substitutions will still be readily apparent to those skilled in the art. Any and all such modifications, variations, equivalents, and substitutions are intended to fall within the spirit and scope of the invention.

[0041] For the purposes described below, the terms “upper,” “lower,” “right,” “left,” “vertical,” “horizontal,” “top,” “bottom,” “lateral,” “longitudinal,” and their derivatives shall be used in relation to the orientation of the invention as shown in the accompanying drawings. However, it should be understood that various alternative variations of the invention may be taken unless explicitly stated otherwise. It should also be understood that the specific devices shown in the drawings and described in the following description are merely exemplary embodiments of the invention. Therefore, specific dimensions and other physical characteristics relating to the embodiments disclosed herein should not be considered limiting.

[0042] refer to Figure 1-18According to one aspect of the invention, a drug delivery system 10 includes a drive assembly 12, a container 14, a valve assembly 16, and a needle actuator assembly 18. The drive assembly 12, container 14, valve assembly 16, and needle actuator assembly 18 are at least partially located within a housing 20. The housing 20 includes a top portion 22 and a bottom portion 24, but other suitable arrangements of the housing 20 may also be used. In one aspect, the drug delivery system 10 is a syringe device configured to be worn or secured to a user and to deliver a predetermined dose of drug disposed within the container 14 by injection into the user. The system 10 can be used to deliver a "bolus injection," in which drug is delivered over a set time period. Drug can be delivered over a time period of up to 45 minutes, but other suitable injection volumes and durations may also be used. The bolus administration or delivery may be performed with or without specific rate control. The drug delivery system 10 can deliver drug to the user at a variable rate with a fixed pressure. The general operation of the system 10 is described below. Figure 1-18 The details of the drive assembly 12, the needle actuator assembly 18, and other features of the system 10 are shown and described in U.S. Provisional Application No. 62 / 347,899, filed June 9, 2016, which are incorporated herein by reference in their entirety.

[0043] Refer again Figure 1-18 System 10 is configured to be operated by user engagement of actuation button 26, which causes the needle 28 of the needle actuator assembly 18 to pierce the user's skin, actuating the drive assembly 12 to fluidly communicate the needle 28 with and expel fluid or medication from the container 14, and withdrawing the needle 28 after the medication injection is completed. The general operation of the medication delivery system is shown and described in International Publications WO 2013 / 155153 and WO 2014 / 179774, which are incorporated herein by reference in their entirety. The housing 20 of system 10 includes: an indicator window 30 for viewing an indicator device 32 configured to provide the user with indications about the status of system 10; and a container window 31 for viewing the container 14. The indicator window 30 may be a magnifying glass for providing a clear view of the indicator device 32. The indicator device 32 moves with the needle actuator assembly 18 during use of system 10 to indicate the pre-use, used, and post-use status of system 10. The indicator device 32 provides a visual indication of the state, but may also provide other suitable indications as alternatives or additional indications, such as auditory or tactile indications.

[0044] Reference Figure 4-6During 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 the retracted position. During the initial actuation of system 10, as... Figure 7-9 As shown, the drive assembly 12 engages the container 14 to move the container 14 toward the valve assembly 16, which is configured to pierce the closure 36 of the container 14 and allow fluid communication of the medication within the container 14 with the needle 28 via the tube 61, as... Figure 17 and Figure 18 As shown. It is understood that other suitable arrangements may be provided to establish fluid communication between the medication within the container and the needle 28. The actuation assembly 12 is configured to engage the plug 34 of the container 14, which initially moves the container 14 to engage with the valve assembly 16 due to the incompressibility of the fluid or medication within the container 14. Initial actuation of the system 10 is caused by the user engaging the actuation button 26, which releases the needle actuator assembly 18 and the actuation assembly 12, as will be discussed in more detail below. During initial actuation, the needle 28 remains in the retracted position and is about to move to the extended position to administer an injection to the user of the system 10.

[0045] During the use of system 10, such as Figure 10-12 As shown, the needle 28 is in an extended position, at least partially outside the housing 20, where the actuation assembly 12 moves the stopper 34 within the container 14 to deliver medication from the container 14 to the user via the needle 28. In the use position, the valve assembly 16 has pierced the closure 36 of the container 14 to provide fluid communication between the container 14 and the needle 28. This also allows the actuation assembly 12 to move the stopper 34 relative to the container 14, as fluid can be dispensed from the container 14. In the post-use position of the system 10, as... Figure 13-15D As shown, needle 28 is in the retracted position and engages with pad 38 to seal needle 28 and prevent any residual fluid or drug from flowing out of container 14. Container 14 and valve assembly 16 can be those shown and described in International Publication No. WO 2015 / 081337, which is incorporated herein by reference in its entirety.

[0046] Reference Figures 15A-15DWhen the needle actuator body 96 moves from the used position to the post-use position, the pad 38 is biased into the needle actuator body 96. 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 with the cam track 126 to deflect the pad arm 122 downward, allowing the pad 38 to pass under the needle 28 before being biased upward into it. The torsion bar 128 allows the pad arm 122 to twist about a pivot of the needle actuator body 96. The pad 38 can be press-fitted into the opening of the pad arm 122, but other suitable arrangements can also be used to secure the pad 38.

[0047] Reference Figure 1-18 A drive assembly 12 according to one aspect of the invention is shown. As described above, the drive assembly 12 is configured to move a container 14 to pierce the closure 36 of the container 14 and also to move a stopper 34 within the container 14 to dispense fluid or medication from the container 14. The drive assembly 12 is shown and described in further detail in the aforementioned U.S. Provisional Application No. 62 / 347,899, and is configured to engage and cooperate with a spacer assembly 40 received by the stopper 34 of the container. 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 that engages with a corresponding threaded portion of the stopper 34, but other suitable arrangements may also be used. The spacer 42 also includes a threaded portion that engages with a corresponding second threaded portion of the spacer retainer 44 for securing the spacer 42 to the spacer retainer 44, but other suitable arrangements may also be used. The drive assembly 12 is configured to dispense a series of predetermined filling volumes into the container 14 while maintaining the functional characteristics of the system 10 described above, including but not limited to retracting the needle 28 after the dose is dispensed and providing an indication of the status of the system 10, while also minimizing abrupt engagement of the drive assembly 12 with the stopper 34. The drive assembly 12 is configured to dispense multiple discrete filling volume ranges 42 by utilizing spacers 42 of various sizes. In one aspect, twelve filling volume ranges and twelve spacer 42 sizes are provided. In another aspect, the length of the spacers 42 is varied to accommodate different filling volumes in the container 14. Alternatively, a single-size spacer 42 may be used, and multiple filling volumes in the container 14 may be accommodated by utilizing multiple pads received by the spacers 42.

[0048] Continue to refer to Figure 1-18The drive assembly 12 includes a first plunger member 52, a second plunger member 54 telescopically received by the first plunger member 52, a first biasing member 56, and a second biasing member 58. The first plunger member 52 is movable from a pre-use position to a use position and to a post-use position, wherein the first plunger member 52 is configured to engage with the spacer assembly 40 and move the stopper 34 within the container 14 to dispense medication 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 arrangement, wherein the second plunger member 54 is configured to move axially after the first plunger member 52 has moved a predetermined axial distance. The movement of the first plunger member 52 and the second plunger member 54 is provided by the first biasing member 56 and the second biasing member 58, which are compression springs, but other suitable arrangements for the biasing members 56 and 58 may also be used.

[0049] The first biasing member 56 is received by the second plunger member 54 and constrained between the plunger actuation member and the indexing member and the first spring seat of the second plunger member 54. The second biasing member 58 is radially inwardly positioned from the first biasing member 56 and received by the second plunger member 54. The second biasing member 58 is constrained between the second spring seat of the second plunger member 54 and the first plunger member 52. The second biasing member 58 is configured to bias the first plunger member 52 toward the container 14 from the pre-use position to the use position and to the post-use position. The first biasing member 56 is configured to bias the second plunger member 54 toward the container 14, which in turn biases the first plunger member 52 toward the container 14 from the pre-use position to the use position and to the post-use position. More specifically, the second biasing member 58 is configured to drive the first plunger member 52 against the spacer assembly 40 or the plug 34 to move the container 14 into engagement with the valve assembly 16, thereby piercing the closure 36 of the container 14 and enabling fluid communication between the container 14 and the needle 28 via the tube 61, as... Figure 17 and Figure 18 As shown. The first biasing member 56 is configured to move the stopper 34 within the container 14 to dispense the drug within the container 14. The second biasing member 58 has a different spring constant than the first biasing member 56. In particular, the second biasing member 58 is stiffer than the first biasing member 56 to provide a larger force for piercing the closure 36 of the container 14, while the first biasing member 56 provides a smaller force for dispensing, depending on the viscosity of the fluid or drug within the container.

[0050] When the actuator button 26 is engaged and the needle actuator assembly 18 is released (which will be discussed in more detail below), the needle actuator assembly 18 moves within the housing 20 from a pre-use position to a use position and then to a post-use position. During the initial movement of the needle actuator assembly 18, a portion of the needle actuator assembly 18 engages with the drive surface of the plunger actuator member to move the plunger actuator member 60 from a first rotational position to a second rotational position.

[0051] Reference Figure 10-11 13 and 17, the second plunger member 54 includes a plurality of coded protrusions 84, wherein a pre-selected one of the plurality of coded protrusions 84 is configured to engage with a restraining member or baffle member 86 of system 10. As described in more detail below, the restraining member 86 cooperates with and restricts movement of the needle actuator assembly 18 from a use position to a post-use position until the stopper 34 reaches a predetermined dose-end position. In one aspect, the restraining member 86 is configured to restrict axial movement of the needle actuator assembly 18 from the use position by engagement between the restraining member 86 and a portion thereof. When the stopper 34 reaches the dose-end position, this engagement between the restraining member 86 and the needle actuator assembly 18 is released by rotation of the restraining member 86. During the use position of the needle actuator assembly 18, the restraining member 86 is biased in the rotational direction, wherein rotation of the restraining member 86 is prevented by engagement between the restraining member 86 and one of the plurality of coded protrusions 84 of the second plunger member 54. The plurality of coded protrusions 84 may be axial ribs of varying lengths, but other suitable arrangements may also be used. Each coded protrusion 84 defines the position in which the limiting member 86 can rotate to release the needle actuator assembly 18. The smooth portion of the second plunger member 54 may also provide additional "coding" for determining when the system 10 transitions to the dose end position.

[0052] As described above, as the system 10 moves from the pre-use position, the use position, and the post-use or dose-end position, the indicator device 32 moves, with different portions of the indicator device 32 visible through the indicator window 30. More specifically, the indicator device 32 engages a portion of the restraining member 86 and moves together with the restraining member 86 at various stages of the system 10 to provide the user with indications about the status of the system 10.

[0053] During the assembly of system 10, the dose of container 14 is matched with a specific spacer 42 of a predetermined length, and a corresponding one of the plurality of coded protrusions 84 is aligned with the restraining member 86. Correspondingly, as described above, container 14 may be provided with multiple dose volumes, each corresponding to a specific spacer 42 and coded protrusion 84. Thus, even for different dose volumes, system 10 is configured to inject needle 28 into the user to deliver a dose of medication from container 14, retract needle 28 after the dose is administered, and provide an indication of the status of system 10 while minimizing abrupt engagement of the actuator assembly 12 with the stopper 34. In particular, 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 damping is not required.

[0054] Refer again Figure 1-18 A needle actuator assembly 18 according to one aspect of the 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 received by the needle shuttle 102 and configured to be in fluid communication with a container 14, as described above. The needle actuator body 96 is generally rectangular, wherein the guide surface 98 projects radially inward. The needle shuttle 102 is received within the needle actuator body 96. As described above, the needle actuator body 96 is capable of being moved from its pre-use position (in the housing 20) within the housing 20. Figure 4-6 (shown in the image), initial actuation position ( Figure 7-9 ), Location of use ( Figure 10-12 ) and location after use ( Figure 13-15D The needle actuator body 96 is biased from the pre-use position to the post-use position via the tension spring 106, but other suitable biasing arrangements may also be used. When the actuator button 26 is engaged, the needle actuator body 96 is released and freely moves from the pre-use position to the use position. After the restraining member 86 rotates, the needle actuator body 96 moves from the use position to the post-use position.

[0055] Continue to refer to Figure 1-18The needle shuttle 102 is movable along a vertical axis between a retracted position where the needle 28 is positioned within the housing 20 and an extended position where at least a portion of the needle 28 extends out of the housing 20. The needle shuttle 102 is configured to move between the retracted and extended positions via engagement between a guide surface 98 of the needle actuator body 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, wherein the first cam member 108 is spaced apart from the second cam member 110. The housing 20 includes a guide post 112 with a recess configured to receive a T-shaped protrusion 114 on the needle shuttle 102; however, other shapes and configurations may be used 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 post 112 is linear and extends generally perpendicularly from the housing 20; however, other suitable arrangements may also be used. The guide surface 98 of the needle actuator body 96 is non-linear and includes a first side and a second side positioned opposite to the first side.

[0056] As described below, the guide surface 98 of the needle actuator body 96 cooperates with the cam members 108, 110 of the needle shuttle 102 to vertically move the needle shuttle 102 between a retracted position and an extended position when the needle actuator body 96 is axially moved from a pre-use position to a post-use position. The needle shuttle 102 also includes a shuttle biasing member (not shown) configured to engage the housing 20 or the actuator button 26. In particular, the shuttle biasing member engages the housing 20 or the actuator button 26 and provides biasing force when the needle actuator body 96 is switched from the use position to the post-use position. When the needle actuator body 96 is fully switched to the post-use position, the cam members 108, 110 of the needle shuttle 102 disengage from the guide surface 98 of the needle actuator body 96, and the shuttle biasing member biases the needle shuttle 102 downward, causing the needle 28 to engage the pad 38 as discussed above. However, as described above... Figure 1-18 As discussed, pad 38 can also be biased into needle 28, instead of biasing needle bobbin 102 downwards via bobbin bias member 120. Needle actuator body 96 can interact with actuator button 26 to prevent actuator button 26 from springing back to the used position, which will be discussed in detail below.

[0057] Reference Figure 3-15D Before use (position) Figure 5-6 The needle shuttle 102 is in the retracted position, wherein the cam members 108, 110 are spaced apart from the guide surface 98 of the needle actuator body 96. When the actuator body 96 moves to the use position ( Figure 10-12 During the retracted position, the second cam member 110 of the needle shuttle 102 engages the guide surface 98 to move the needle shuttle 102 from the retracted position to the extended position. This occurs during the transition of the needle actuator body 96 from the used position to the post-use position. Figure 13-15D The first cam member 108 of the needle shuttle 102 continues to engage the guide surface 98 to move the needle shuttle 102 from the extended position to the retracted position. After the needle actuator body 96 has fully transitioned to the used position, as the cam members 108, 110 disengage from the guide surface 98 of the needle actuator body 96 with the needle 28 engaging the pad 38, the shuttle biasing member biases the needle shuttle 102 downward.

[0058] Now refer to Figure 17-18 and Figures 19A-19B The diagram illustrates a dose end detection device, generally designated 71. The dose end device functions as an in-line pressure sensor to prevent movement of the needle actuator during fluid delivery and to control the withdrawal of the needle 28 from the patient at the end of the drug dose. The dose end detection device 71 includes an expandable portion or balloon 73 in tube 61, which is in fluid communication with container 14 and needle 28. During drug delivery, the expandable portion 73 is configured to expand upon actuation of drive assembly 12 to prevent movement of needle actuator assembly 18 and withdrawal of needle 28. The expandable portion 73 is also configured to collapse or remain in a non-expanded state at the end of the drug dose due to a drop in drug pressure caused by the lack of drug within container 14. When the expandable portion is in the non-expanded state, as... Figure 19A As shown, the needle actuator assembly 18 is permitted to be moved to a post-use position, thereby retracting the needle 28 from the patient's body. An example of the tube 61 including the expandable portion 73 could be a SmartForm available from Creganna Tactx Medical. TM A balloon catheter is used, but it is understood that other balloon catheters may be used in this invention. It is also understood that the dose end detection device 71 may be used in conjunction with a drug delivery device or a syringe.

[0059] Continue to refer to Figure 17-18 According to one embodiment, a portion of tube 61 straddles a slot 75 on the top portion 77 of needle actuator assembly 18. When device 10 is activated, needle actuator assembly 18 is stopped by a restraining member or baffle 86, which straddles a plug or plunger member 34 when needle 28 is inserted into the patient. Pressure in the fluid path increases, and expandable portion 73 expands or inflates. Movement of plug or plunger member 34 releases restraining member or baffle 86, allowing needle actuator assembly 18 to be held by expandable portion 73 while the needle remains in the patient. As pressure in fluid path or tube 61 decreases at the end of the dose, expandable portion 73 deflates and allows needle actuator assembly 18 to retract needle 28 from the patient.

[0060] The use of the dosing end device 71 of the present invention allows the stopper or plunger component 34 to touch the bottom of the container 14 and to automatically withdraw the needle 28 from the patient after the dose is finished.

[0061] An element of one disclosed aspect may be combined with elements of one or more other disclosed aspects to form different combinations, all of which are considered to be within the scope of the invention.

[0062] Although this disclosure has been described as having an exemplary design, further modifications can be made to this disclosure within its spirit and scope. Therefore, this application is intended to cover any variations, uses, or adaptations of this disclosure using its general principles. Furthermore, this application is intended to cover such deviations from this disclosure that fall within the known or customary practice in the field to which this disclosure pertains and fall within the limitations of the appended claims.

Claims

1. A drug delivery system for injecting a drug, the drug delivery system comprising: a container configured to deliver a drug; a drive assembly configured to expel the drug from the container upon actuation; a needle for injecting the drug into a patient; a needle actuator assembly comprising a movable portion biased by a biasing member and configured to move the needle between a pre-use position, a use position for delivering the drug to the patient, and a post-use position after the delivery of the drug is complete; and a tube in fluid communication with the container and the needle, the tube comprising an expandable portion having an expanded state and a non-expanded state, wherein the expandable portion is configured to be in the expanded state upon actuation of the drive assembly and in the non-expanded state when the needle is in the post-use position, wherein the expandable portion comprises a balloon that is inflated to the expanded state upon actuation of the drive assembly.

2. The drug delivery system of claim 1, wherein, The expandable portion of the tube is in the non-expanded state when the needle is in the pre-use position.

3. The drug delivery system of claim 1, wherein, The movable portion of the needle actuator assembly engages the expandable portion of the tube when the expandable portion of the tube is in the expanded state.

4. The drug delivery system of claim 1, wherein, The expandable portion of the tube is configured to be in the expanded state by action of pressure within the container caused by actuation of the drive assembly.

5. The drug delivery system of claim 4, wherein, The expandable portion of the tube is configured to change from the expanded state to the non-expanded state when the pressure within the container caused by actuation of the drive assembly is reduced due to lack of drug within the container.

6. The drug delivery system of claim 3, wherein, The engagement between the needle actuator assembly and the tube is released when the tube is in the non-expanded state, thereby allowing the needle actuator assembly to move and retract the needle.

7. The drug delivery system of claim 1, further comprising a housing that encloses at least a portion of the container, the drive assembly, the needle, the needle actuator assembly, and the tube.

8. The drug delivery system of claim 7, wherein, In the use position, at least a portion of the needle extends from the housing.

9. The drug delivery system of claim 1, wherein, The tube is associated with the needle actuator assembly.

10. The drug delivery system of claim 9, wherein, The drug delivery system comprises a slot in the needle actuator assembly configured to receive a portion of the tube.

11. A drug delivery system for injecting a drug, the drug delivery system comprising: a container configured to deliver a drug; a drive assembly configured to expel the drug from the container upon actuation; a needle for injecting the drug into a patient; a needle actuator assembly comprising a movable portion biased by a biasing member and configured to move the needle between a pre-use position, a use position for delivering the drug to the patient, and a post-use position after the delivery of the drug is complete; a tube connecting the container to the needle; and a dose end detection assembly that prevents the needle actuator assembly from moving during drug delivery, wherein the end-of-dose detection assembly includes a balloon that inflates to an expanded state upon actuation of the drive assembly and during drug delivery, and the balloon collapses to allow movement of the needle at the end of dose.

12. The drug delivery system of claim 11, wherein, The balloon collapses due to a pressure drop in a fluid path defined between the container and the needle.

13. The drug delivery system of claim 11, wherein, The balloon radially expands during drug delivery.

14. The drug delivery system of claim 11, wherein, The end-of-dose detection assembly is configured to allow movement of the needle actuator assembly to the post-use position when the balloon is in a non-expanded state.

15. The drug delivery system of claim 11, wherein, The end-of-dose detection assembly is configured to retain the needle actuator assembly when the balloon is in an expanded state.

16. The drug delivery system of claim 11, further comprising: a stopper configured to move within the container to expel drug from the container; and a restriction member configured to restrict movement of the needle actuator assembly from the use position to the post-use position until the stopper reaches a predetermined end-of-dose position, wherein movement of the stopper releases the restriction member such that the end-of-dose detection assembly retains the needle actuator assembly in the use position.

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