WO2022066901A1

WO2022066901A1 - Biasing member for medical injection device

Info

Publication number: WO2022066901A1
Application number: PCT/US2021/051746
Authority: WO
Inventors: Bradley M. Wilkinson; Stephen C. SIMMONS; Stephen SIMANTIRAS; Kayla KASPAR
Original assignee: Becton, Dickinson And Company
Priority date: 2020-09-25
Filing date: 2021-09-23
Publication date: 2022-03-31

Abstract

A biasing member for a medical injection device having a housing, a brake member, a cartridge, and an injection needle, with the biasing member including an annular body having a top surface and a bottom surface positioned opposite the top surface, and a raised portion extending from the body in a direction extending from the bottom surface of the body to the top surface of the body. The raised portion is resilient.

Description

BIASING MEMBER FOR MEDICAL INJECTION DEVICE

CROSS-REFERENCE TO RELATED APPLICATION

[0001] The present application claims priority to United States Provisional Application No. 63/083,550, entitled “Biasing Member for Medical Injection Device”, filed September 25, 2020, the entire disclosure of which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

[0002] The present disclosure relates generally to a biasing member for a medical injection device.

Description of Related Art

[0003] Medical injection devices often utilize resilient members, such as springs, placed between various components, to bias the components in order to ensure more accurate drug delivery. However, there are shortcomings to the use of current resilient members used in medical injection devices, such as a lack of control and load recovery. Accordingly, there is a need in the art for a more robust component to allow for greater load recovery.

SUMMARY OF THE INVENTION

[0004] In one aspect or embodiment, a biasing member for a medical injection device having a housing, a brake member, a cartridge, and an injection needle, includes an annular body having a top surface and a bottom surface positioned opposite the top surface, and a raised portion extending from the body in a direction extending from the bottom surface of the body to the top surface of the body. The raised portion is resilient.

[0005] The raised portion may extend from the top surface of the body. The raised portion may be curved. The raised portion may be semi-cylindrical. The annular body may define an opening positioned adjacent to the raised portion. The biasing member may further include a plurality of projections extending radially outward from the annular body, with the plurality of projections configured to engage the housing. The bottom surface of the body may be configured to engage a portion of the cartridge, with the raised portion configured to engage the brake member. The biasing member may be formed from a metallic material. The annular body may be integrally formed with the raised portion. A cross-sectional thickness of the annular body and the raised portion may be equal. The raised portion may include a plurality of raised portions equally spaced apart from each other. [0006] In a further aspect or embodiment, a medical injection device includes a housing having a distal end and a proximal end, a brake member received within the housing, a cartridge received within the housing, the cartridge configured to receive a medicament, a cartridge housing received within the housing distally of the brake member and configured to hold the cartridge, a biasing member according to any aspect or embodiment described above, with the biasing member received within the housing and positioned between the brake member and the cartridge, an injection needle at the distal end of the housing and in fluid communication with the cartridge, and an actuation member configured to actuate the medical injection device to deliver the medicament through the injection needle.

[0007] The bottom surface of the body of the biasing member may be engaged with the cartridge.

[0008] In another aspect or embodiment, a biasing member for a medical injection device having a housing, a brake member, a cartridge, and an injection needle, includes a first annular member having a top surface and a bottom surface positioned opposite the top surface, a second annular member having a top surface and a bottom surface positioned opposite the top surface, a plurality of connecting members each having a first end and a second end positioned opposite to the first end, with each of the connecting members extending between the first annular member and the second annular member. Each of the connecting members is resilient.

[0009] The first end of each connecting member may be attached to the first annular member and the second end of each connecting member may be attached to the second annular member. The plurality of connecting members may be configured to be biased radially inward upon movement of the first annular member toward the second annular member.

[0010] In a further aspect or embodiment, a medical injection device includes a housing having a distal end and a proximal end, a brake member received within the housing, a cartridge received within the housing, the cartridge configured to receive a medicament, a cartridge housing received within the housing distally of the brake member and configured to hold the cartridge, a biasing member according to the aspect or embodiment described above, the biasing member received within the housing and positioned between the brake member and the cartridge, an injection needle at the distal end of the housing and in fluid communication with the cartridge, and an actuation member configured to actuate the medical injection device to deliver the medicament through the injection needle.

[0011] The first annular member may be engaged with the cartridge and the second annular member may be engaged with the brake member. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is a perspective view of a medical injection device according to one aspect or embodiment of the present application.

[0013] FIG. 2 is an exploded view of the medical injection device of FIG. 1.

[0014] FIG. 3A is a partial perspective view of a brake member, biasing member, and cartridge of the medical injection device of FIG. 1.

[0015] FIG. 3B is an enlarged view of the biasing member of FIG. 3 A.

[0016] FIG. 4 is a partial cross-sectional view of the medical injection device of FIG. 1, showing a pre-engagement position of the biasing member.

[0017] FIG. 5 is a partial cross-sectional view of the medical injection device of FIG. 1, showing an engagement position of the biasing member.

[0018] FIG. 6 is a partial perspective view of a medical injection device according to another aspect or embodiment of the present application.

[0019] FIG. 7 is a partial cross-sectional view of the medical injection device of FIG. 6, showing a pre-engagement position of the biasing member.

[0020] FIG. 8 is a partial cross-sectional view of the medical injection device of FIG. 6, showing an engagement position of the biasing member.

DESCRIPTION OF THE INVENTION

[0021] The use of numerical values in the various ranges specified in this application, unless expressly indicated otherwise, are stated as approximations as though the minimum and maximum values within the stated ranges are both preceded by the word “about”. As used herein, the term “about” means the stated value ± 10%. In this manner, slight variations above and below the stated ranges can be used to achieve substantially the same results as values within the ranges. Also, unless indicated otherwise, the disclosure of these ranges is intended as a continuous range including every value between the minimum and maximum values. For definitions provided herein, those definitions refer to word forms, cognates and grammatical variants of those words or phrases.

[0022] The figures accompanying this application are representative in nature, and should not be construed as implying any particular scale or directionality, unless otherwise indicated. For purposes of the description hereinafter, the terms “upper”, “lower”, “right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “lateral”, “longitudinal” and derivatives thereof shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting. [0023] Referring to FIGS. 1-5, according to one aspect or embodiment of the present application, a medical injection device 10 includes a button 12, button spring 14, dose set knob 16, bearing insert 18, driver 20, housing 22, a biasing member 24, a brake member 28, lead screw 30, piston rod 32, stopper 34, cartridge 36, cartridge housing 38, cap 40, outer shield 42, and needle 44. The medical injection device 10 is utilized to deliver a medicament or composition contained within the cartridge 36 to a person. The medical injection device 10 may be similar and operate in the same manner as the injection device shown and described in U.S. Patent No. 9,421,334, which is incorporated herein by reference in its entirety.

[0024] Referring to FIGS. 1 and 2, the housing 22 receives a plurality of dose setting and injection components. The housing 22 is connected to the cartridge housing 38, which receives the cartridge 36. The cap 40 covers the cartridge 36 and the cartridge housing 38 when the injection device 10 is not in use. The dose set knob 16 includes a knob-like portion that is rotated by a person to set a desired dose. The dose set knob 16 can also include a plurality of numerals or markings 46 that correspond to a number of dosage units that are visible through a window 48 provided on the housing 22. The dose set knob 16 is rotated until the desired dose is visible in the window 48. The housing 22 can include an arrow or other indicator 50 to precisely indicate the set dose. Once the desired dose is set, the button 12 is pressed until the set dosage amount is completely injected. The outer shield 42 can cover the needle 44 to prevent accidental needle sticks upon removal of cap 40.

[0025] The button 12 can include an annular bead or rim 52 that engages with a corresponding annular groove (not shown) provided on the internal surface of the dose set knob 16. The annular rim 52 and groove connection can be a friction fit that maintains the push button 12 in a biased position on the dose set knob 16 under the force of the button spring 14, but allows the button 12 to be pushed into the dose set knob 16 for injecting a set dose. The interior of the button 12 can accommodate the bearing insert 18 that rests on an internal surface at a proximal end of the driver 20. The push button 12 can be designed to rotate freely on the bearing insert 18.

[0026] The driver 20 can be a cylindrical member, coaxial with and surrounded by the dose set knob 16. The driver 20 can be provided co-axially around the brake member 28, which is axially and rotatably fixed to the housing 22. The brake member 28 co-axially surrounds the piston rod 32. The piston rod 32 includes a set of keys (not shown) that engage a slot (not shown) internal to the brake member 28 to rotatably lock the piston rod 32 to the brake member 28. The piston rod 32 can include a plurality of threads (not shown) provided on the interior surface thereof. The piston rod 32 co-axially surrounds the lead screw 30, which includes a series of threads 54 at least at its distal end. The lead screw threads 54 are configured to be in threaded engagement with the internal threads (not shown) provided on the interior of the piston rod 32. Due to its threaded engagement with the lead screw 30, the piston rod 32 can be moved into the cartridge 36 during injection to press on the stopper 34 provided inside the cartridge 36 to expel a dose of medication from the cartridge 36. To set a dose using the injection device 10 as described herein, a user rotates the knob portion of the dose set knob 16 relative to the housing 22. An outer surface of the dose set knob 16 can include a thread 56 that is in threaded engagement with a plurality of threads 58 provided on the internal surface of the housing 22. Accordingly, as the dose set knob 16 is rotated relative to the housing 22, the dose set knob 16 screws or advances a distance out of the housing 22.

[0027] With regard to the injection mechanism, as described above, the lead screw 30 includes the plurality of threads 54 at its distal end that engage with a plurality of threads (not shown) provided along the entire length of a hollow piston rod 32. The piston rod 32 is held non-rotatably with respect to the housing 22 due to a non-rotatable coupling with the brake member 28, which can be held axially and rotatably fixed with respect to the housing 22. The piston rod 32 can include a key or set of keys 60 at its distal end that engage with a slot (not shown) provided on the internal surface of the brake member 28 to prevent relative rotation therebetween while permitting the piston rod 32 to move axially with respect thereto. The threads 54 of the lead screw 30 can include a flat portion (not shown) corresponding to a flat portion 62 of the piston rod 32, such that axial movement of the lead screw 30 during dose setting does not result in axial movement of the piston rod 32. Accordingly, rotation of the lead screw 30 during injection of a dose can cause the threads 54 of the lead screw 30 to engage the threads of the piston rod 32, thereby axially moving the piston rod 32. Because the piston rod 32 can be non-rotatable with respect to the housing 22, as the lead screw 30 is caused to rotate during injection, as described above due to its rotational coupling with the driver 20, the piston rod 32 through its threaded engagement with the lead screw 30 can be caused to move in the distal direction to press against the stopper 34 provided in the medicament cartridge 36, thus expelling a liquid medication therefrom.

[0028] Referring to FIGS. 1-5, the biasing member 24 of the injection device 10 is positioned between a distal end 70 of the brake member 28 and the cartridge 36 in an axial direction to bias the cartridge 36 in a distal direction to prevent movement of the cartridge 36 during injection thereby ensuring an accurate dose is injected. As shown in FIGS. 4 and 5, during assembly of the device 10 and prior to insertion of the cartridge 36 (FIG. 4), the biasing member 24 has an unbiased position where the biasing member 24 has a maximum length. After assembly of the device 10 with the cartridge 36 inserted and engaged with the biasing member 24 (FIG. 5), the biasing member 24 is in a biased position where the biasing member 24 is compressed with a length less than the maximum length of the biasing member 24.

[0029] Referring to FIGS. 3A and 3B, the biasing member 24 includes an annular body 74 having a top surface 76 and a bottom surface 78 positioned opposite the top surface 76 and a plurality of raised portions 80 extending from the annular body 74 in a direction extending from the bottom surface 78 of the annular body 74 to the top surface 76 of the annular body 74. The raised portions 80 are resilient. The raised portions 80 may be resilient due to the geometry and/or material of the raised portions 80. The raised portions 80 extend from the top surface 76 of the annular body 74. Each of the raised portions 80 is curved and, more specifically, may be semi-cylindrical. The annular body 74 defines a plurality of openings 82 adjacent to each raised portion 80. The biasing member 24 includes a plurality of projections 84 extending radially outward from the annular body 74. The plurality of projections 84 are configured to engage and provide a friction fit with the housing 22. The bottom surface 78 of the annular body 74 is configured to engage a portion of the cartridge 36 and the raised portions 80 are configured to engage the brake member 28. Although four equally-shaped raised portions 80 are provided, one or more raised portions 80 may be utilized. In one aspect or embodiment, three raised portions 80 are provided to allow for three points of contact with the brake member 28.

[0030] In one aspect or embodiment, the biasing member 24 is manufactured or formed from a metallic material, such as spring steel, although other suitable materials may be utilized. In one aspect or embodiment, the biasing member 24 is formed from a polymeric material, such as nylon or polypropylene.

[0031] In one aspect or embodiment, the annular body 74 and the raised portions 80 are integrally formed with each other. The biasing member 24 is configured to be formed as a single, unitary piece. A cross-sectional thickness of the annular body 74 and the raised portions 80 are equal. The biasing member 24 may be manufactured via a stamping and/or die cut process, although other suitable processes may be utilized.

[0032] Referring to FIGS. 6-8, a biasing member 102 according to a further aspect or embodiment of the present application is shown. The biasing member 102 may replace the biasing member 24 discussed above and would function in a similar manner. As shown in FIGS. 7 and 8, during assembly of the device 10 and prior to insertion of the cartridge 36 (FIG. 7), the biasing member 102 has an unbiased position where the biasing member 102 has a maximum length. After assembly of the device 10 with the cartridge 36 inserted and engaged with the biasing member 102 (FIG. 8), the biasing member 102 is in a biased position where the biasing member 102 is compressed with a length less than the maximum length of the biasing member 102.

[0033] The biasing member 102 includes a first annular member 104 having a top surface 106 and a bottom surface 108 positioned opposite the top surface 106, and a second annular member 110 having a top surface 112 and a bottom surface 114 positioned opposite the top surface 112. The biasing member 102 further includes a plurality of connecting members 116 each having a first end 118 and a second end 120 positioned opposite the first end 118. Each of the connecting members 116 extends between the first annular member 104 and the second annular member 110. Each of the connecting members 116 is resilient. The connecting members 116 may be resilient due to the material and/or geometry of the connecting members 116. The first end 118 of each connecting member 116 is attached to the first annular member 104 and the second end 120 of each connecting member 116 is attached to the second annular member 110. In one aspect or embodiment, each connecting member 116 is a vertical post or L-shaped post extending between the first and second annular members 104, 110. The connecting members 116 are configured to be biased radially inward upon movement of the first annular member 104 toward the second annular member 110. In one aspect or embodiment, the housing 22 is configured to constrain the connecting members 116 such that the connecting members 116 are biased inwardly upon compression of the biasing member 102. The first annular member 104 is configured to be engaged with the cartridge 36 and the second annular member 110 is configured to be engaged with the brake member 28.

[0034] In one aspect or embodiment, the connecting members 116 are initially biased radially outward, but are deflected and biased inward upon movement of the first annular member 104 toward the second annular member 110 when constrained by the housing 22.

[0035] In one aspect or embodiment, the biasing member 102 is manufactured or formed from a polymeric material, although other suitable non-brittle plastically deforming or elastomeric materials may be utilized.

[0036] In one aspect or embodiment, the first annular member 104, the second annular member 110, and the connecting members 116 are formed integrally with each other. The biasing member 102 is configured to be formed as a single, unitary piece. The biasing member 102 may be manufactured via 3D printing or a molding process, such as a plastic injection molding process, although other suitable processes may be utilized. [0037] Although the devices have been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the systems and methods are not limited to the disclosed embodiments, but on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present systems and methods contemplate that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.

Claims

THE INVENTION CLAIMED IS:

1. A biasing member for a medical injection device having a housing, a brake member, a cartridge, and an injection needle, the biasing member comprising: an annular body having a top surface and a bottom surface positioned opposite the top surface; and a raised portion extending from the body in a direction extending from the bottom surface of the body to the top surface of the body, wherein the raised portion is resilient.

2. The biasing member of claim 1, wherein the raised portion extends from the top surface of the body.

3. The biasing member of claim 1 or claim 2, wherein the raised portion is curved

4. The biasing member of any of claims 1-3, wherein the raised portion is semi- cylindrical.

5. The biasing member of any of claims 1-4, wherein the annular body defines an opening positioned adjacent to the raised portion.

6. The biasing member of any of claims 1-5, further comprising a plurality of projections extending radially outward from the annular body, wherein the plurality of projections are configured to engage the housing.

7. The biasing member of any of claims 1-6, wherein the bottom surface of the body is configured to engage a portion of the cartridge, and wherein the raised portion is configured to engage the brake member.

8. The biasing member of any of claims 1-7, wherein the biasing member comprises a metallic material.

9. The biasing member of any of claims 1-8, wherein the annular body is integrally formed with the raised portion.

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10. The biasing member of any of claims 1-9, wherein a cross-sectional thickness of the annular body and the raised portion are equal.

11. The biasing member of any of claims 1-10, wherein the raised portion comprises a plurality of raised portions equally spaced apart from each other.

12. A medical injection device comprising: a housing having a distal end and a proximal end; a brake member received within the housing; a cartridge received within the housing, the cartridge configured to receive a medicament; a cartridge housing received within the housing distally of the brake member and configured to hold the cartridge; a biasing member according to any of claims 1-11, the biasing member received within the housing and positioned between the brake member and the cartridge; an injection needle at the distal end of the housing and in fluid communication with the cartridge; and an actuation member configured to actuate the medical injection device to deliver a medicament through the injection needle.

13. The medical injection device of claim 12, wherein a bottom surface of a body of the biasing member is engaged with the cartridge.

14. A biasing member for a medical injection device having a housing, a brake member, a cartridge, and an injection needle, the biasing member comprising: a first annular member having a top surface and a bottom surface positioned opposite the top surface; a second annular member having a top surface and a bottom surface positioned opposite the top surface; a plurality of connecting members each having a first end and a second end positioned opposite to the first end, each of the connection members extending between the first annular member and the second annular member, wherein each of the connecting members is resilient.

15. The biasing member of claim 14, wherein the first end of each connecting member is attached to the first annular member and the second end of each connecting member is attached to the second annular member.

16. The biasing member of claim 14 or claim 15, wherein the plurality of connecting members are configured to be biased radially inward upon movement of the first annular member toward the second annular member.

17. A medical injection device comprising: a housing having a distal end and a proximal end; a brake member received within the housing; a cartridge received within the housing, the cartridge configured to receive a medicament; a cartridge housing received within the housing distally of the brake member and configured to hold the cartridge; a biasing member according to any of claims 14-16, the biasing member received within the housing and positioned between the brake member and the cartridge; an injection needle at the distal end of the housing and in fluid communication with the cartridge; and an actuation member configured to actuate the medical injection device to deliver the medicament through the injection needle.

18. The medical injection device of claim 17, wherein the first annular member is engaged with the cartridge and the second annular member is engaged with the brake member.

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