Medical injection device
The medical injection device addresses assembly complexity and actuation resistance by using a preloaded resilient element to generate an acoustic signal, reducing parts and ensuring clear feedback without process interruptions.
Patent Information
- Application Number
- JP2025187885
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-02-02
- Filing Date
- 2025-11-06
- Publication Date
- 2026-02-03
AI Technical Summary
Existing medical injection devices face issues with complex assemblies, increased manufacturing effort, susceptibility to failure, and undesirable interruptions due to high actuation resistance in generating acoustic feedback, often requiring multiple parts and lacking multifunctional components.
A medical injection device with a housing, actuation element, and resilient element, where the resilient element is preloaded and configured to move relative to the housing, generating an acoustic signal by a striking portion striking a receiving portion upon injection completion, reducing parts and actuation resistance.
The configuration minimizes assembly complexity, manufacturing effort, and reduces the risk of interruptions, while providing a clear acoustic signal with reduced parts and improved actuation efficiency.
Smart Images
Figure 2026016780000001_ABST
Abstract
Description
[Technical Field]
[0001] The present disclosure relates to a medical injection device configured to generate an acoustic signal. [Background technology]
[0002] For medical injection devices, such as automatic injection devices or pen injectors, it is often necessary to provide feedback to the patient upon reaching and / or releasing a particular operating state of the medical injection device. For example, in the case of an automatic injector that injects an emergency medication, such as adrenaline, in the event of allergic shock, it is necessary to let the patient know when the medication has been fully administered. Otherwise, it is impossible to know if the injection has been interrupted, for example, due to a technical malfunction. It is understood that this can pose a significant health risk to the patient.
[0003] It has been found that acoustic feedback is often required in addition to a visual indication of the extent to which a substance has been administered from a medical injection device. The reasons for this are manifold. For example, it must be ensured that feedback is provided to individuals with visual impairments. Furthermore, the injection area may be positioned such that the visual indication is not within the patient's field of view. Furthermore, it is understood that feedback regarding injection status / progress is also required under poor lighting conditions.
[0004] Various solutions are known from the prior art for providing acoustic feedback in medical injection devices, for example when the injection process is completed or started, but these solutions have various drawbacks, as listed below:
[0005] First, prior art medical injection devices configured to provide an acoustic signal, such as those described in WO 2018 / 082886, often include assemblies with multiple parts to generate the acoustic signal. This results in multiple parts, sometimes in complex arrangements. Multiple parts, especially complex arrangements, increase assembly effort and / or time. Furthermore, the presence of multiple parts increases the risk of incorrect assembly. Furthermore, an increased number of parts increases manufacturing effort because more parts must be manufactured. Furthermore, the susceptibility to failure increases, especially if failure of one part leads to failure of the medical injection device and / or the assembly that functions to generate the acoustic signal.
[0006] Second, in prior art medical injection devices configured to provide an acoustic signal, undesirable instances sometimes occur in which the assembly functioning to generate the acoustic signal slows down or even interrupts the injection. One reason for this is that the assembly has a high actuation resistance, which slows down or even interrupts the injection process. Yet another reason may be that an elastic element of the assembly is preloaded toward another component of the medical injection device that is required to move during the injection, thereby preventing that component from moving. A possible example of such a configuration is shown in Figures 4 and 6 of U.S. Patent No. 10,918,811.
[0007] Third, components within a medical injection device that generate an acoustic signal typically have only the function of generating an acoustic signal, although in principle it would be desirable to assign more than one function to individual components of a medical injection device, for example to reduce the total number of components required in the medical injection device. Summary of the Invention [Problem to be solved by the invention]
[0008] Accordingly, it is an object of the present disclosure to provide a medical injection device that at least partially overcomes the above-mentioned drawbacks. [Means for solving the problem]
[0009] This object is at least partly achieved by a medical injection device as defined in the independent claims. Further aspects of the present disclosure are defined in the dependent claims.
[0010] In particular, this object is achieved by a medical injection device comprising a housing having a retaining portion, an actuation element movably disposed within the housing, and a resilient element movably disposed within the housing. In an initial state of the medical injection device, the resilient element is preloaded, and the resilient element comprises an actuation portion, a striking portion, and an abutment portion, the abutment portion being in compressive engagement with the retaining portion in the initial state. The resilient element is configured to move relative to the housing by moving the actuation element toward the actuation portion, such that upon movement, the abutment portion disengages from the retaining portion and expansion of the preloaded resilient element causes the striking portion to strike a striking portion of the medical injection device, thereby generating an acoustic signal.
[0011] The medical injection device may be an auto-injector, a pen injector and / or a syringe, but preferably the medical injection device is an auto-injector, as it is important, particularly for auto-injectors, to let the patient know when the medication has been fully administered and / or when the injection has begun.
[0012] The housing may include multiple components, for example, the housing may have two substantially hollow cylindrical components that are inserted into each other after the components are installed in the housing.
[0013] The retaining portion is preferably formed integrally with the housing, in particular the retaining portion may be formed integrally with the part of the housing that at least partially accommodates the elastic element, thus eliminating the need for a separate retaining portion and reducing the number of parts.
[0014] The term "elastic" as used throughout this disclosure may refer to the ability of a material to withstand elastic deformation without plastic deformation. Thus, a resilient element being preloaded may refer to the manner in which the resilient element is elastically deformed.
[0015] The initial state of the medical injection device can be referred to as the state before the medical injection device starts the injection process.
[0016] Furthermore, the actuating portion, the impact portion and / or the abutment portion may be separable sections of the elastic element, but the actuating portion, the impact portion and / or the abutment portion of the elastic element may also continuously transition into one another and / or overlap.
[0017] The abutting portion compressively engaging the retaining portion in the initial state can also be said to apply pressure to the retaining portion. Furthermore, those skilled in the art will understand that the abutting portion compressively engaging the retaining portion can maintain a preload on the elastic element in the initial state.
[0018] In particular, the resilient element may be configured to move relative to the housing when moved by the actuation element abutting the actuation portion.
[0019] From the manner in which the striking portion strikes the receiving portion due to the extension of the preloaded elastic element, a person skilled in the art will understand that the striking portion may undergo an acceleration process.
[0020] The resilient element may be configured such that after being struck by the striking portion, the preload within the resilient element is reduced to a lower amount or to zero.
[0021] A medical injection device according to the present disclosure has a variety of advantages, at least two of which are described in more detail below.
[0022] First, compared to conventional medical injection devices, the configuration of the present medical injection device allows for a reduced number of parts and / or a less complex arrangement. Therefore, assembly effort and / or assembly time can be reduced. Furthermore, manufacturing effort and / or the risk of incorrect assembly can be minimized. This is due, among other things, to the arrangement of the elastic element and the mechanically simple actuation mechanism that relies on moving the elastic element relative to the housing.
[0023] Secondly, it has been found that the described configuration can achieve reduced injection resistance and / or actuation resistance in the medical injection device. Thus, the risk that actuation of the elastic element will slow down or even interrupt the injection process can be reduced. This is particularly because the elastic element is configured to be movable relative to the housing, which allows for a configuration in which unintended interruptions during movement can be avoided.
[0024] It will be appreciated that the above advantages may also be expressed in various ways as follows:
[0025] The elastic element may be a metal element, which optionally consists of a bent sheet metal. Metal elements have proven to be advantageous since metals do not normally creep. Furthermore, elastic elements made of bent sheet metal are particularly suitable since the bending allows for a precise setting of the preload that the elastic element has in its initial state.
[0026] The elastic element may have an elongated shape, with the longitudinal axis of the elastic element being substantially parallel to the longitudinal axis of the medical injection device. This arrangement allows for a space-saving arrangement of the components. Furthermore, a stable guidance of the elastic element within the housing can be achieved. These advantages are particularly true when the housing has a substantially hollow cylindrical shape.
[0027] The elastic element and / or the actuating element may be configured to move relative to the housing along a direction substantially parallel to the longitudinal axis of the medical injection device, and optionally, the elastic element and / or the actuating element may be configured to move relative to the housing in the injection direction. This arrangement allows the movement of a component within the medical injection device, such as a plunger, that causes the ejection of a substance to be easily used to move the elastic element. Since no redirection of motion is required, this reduces friction and the number of required parts. In particular, the elastic element and the actuating element configured to move relative to the housing in the injection direction allows for a reduction in injection resistance and / or actuation resistance within the medical injection device. This reduces the risk that the actuation of the elastic element will slow down or even interrupt the injection process. The injection direction may be referred to as the direction in which a substance is ejected from the medical injection device. Furthermore, the injection direction may be referred to as the direction in which a cannula of the medical injection device is inserted into the injection area.
[0028] The elastic element may be configured such that the abutment portion disengages from the holding portion when the elastic element moves relative to the housing in the injection direction. This configuration allows, in particular, for reduced injection resistance and / or actuation resistance within the medical injection device, but also allows for a simple configuration of the medical injection device. Illustratively, this configuration allows for the movement of a component within the medical injection device, such as a plunger, that causes the substance to be expelled, to be used to move the elastic element. This eliminates the need for a redirected movement, thereby reducing friction and the number of parts.
[0029] The elastic element may include a bending portion forming a first end of the elastic element. The bending portion allows for specific adjustment of the bending characteristics of the elastic element, particularly when the elastic element is formed from sheet metal. Furthermore, the bending portion may be used to form two spring arms, with the bending portion forming an elastic joint between the spring arms. For example, one spring arm may include an actuating portion, and the other spring arm may include a striking portion and an abutting portion. Furthermore, a more compact design of the elastic element may be achieved by bending, thereby reducing the required installation space. Optionally, in an initial state, the bending portion has a bending angle ranging from 160° to 210°, optionally from 170° to 200°, and even optionally from 180° to 190°. These angles have been proven to allow for sufficient preload within the elastic element.
[0030] The elastic element is configured such that the abutment portion moves in a direction substantially perpendicular to the longitudinal axis of the medical injection device after the abutment portion disengages from the holding portion, and optionally the abutment portion may be configured to move toward the longitudinal axis of the medical injection device. By configuring the elastic element such that the abutment portion moves in a direction substantially perpendicular to the longitudinal axis of the medical injection device after the abutment portion disengages from the holding portion, impacts on portions extending along the longitudinal axis can be achieved. This allows for better sound propagation and thus a clearer acoustic signal. Furthermore, it has been found that by configuring the abutment portion to move toward the longitudinal axis of the medical injection device, the volume of the acoustic signal can be increased, particularly compared to when the abutment portion is configured to move outward from the longitudinal axis of the medical injection device. One reason for this is direct noise attenuation in the event of an outward impact. This is because the medical injection device is surrounded by the patient's hand, whereas an inward impact, i.e., toward the longitudinal axis of the medical injection device, is not the case. However, it is understood that in an alternative configuration, the abutment portion may move away from the longitudinal axis of the medical injection device after it disengages from the holding portion.
[0031] The impact portion may be adjacent to the abutment portion, which allows the striking portion to be subjected to a particularly high acceleration, which allows the acoustic signal to be provided at a high volume.
[0032] The elastic element may comprise a sliding portion in sliding contact with the housing, optionally the sliding portion being in substantial surface contact with the housing. By the sliding contact of the elastic element with the housing, high actuation resistance that would slow down or even interrupt the injection process can be avoided. In particular, by the sliding portion being in substantial surface contact with the housing, particularly low injection and / or actuation resistance can be achieved in the medical injection device.
[0033] Optionally, the strike-receiving portion forms part of the actuating element. This allows the actuating element to perform more than one function within the medical injection device. Therefore, the total number of parts required for the medical injection device can be further reduced. For example, an additional strike-receiving portion does not need to be provided. However, a configuration in which the strike-receiving portion does not form part of the actuating element is also conceivable, for example, if the abutting portion moves away from the longitudinal axis of the medical injection device after disengaging from the holding portion.
[0034] The impact portion may abut the striking portion after striking the striking portion, and optionally the elastic element may remain taut. This prevents the elastic element from loosening within the medical injection device and thereby generating a confusing acoustic signal. Furthermore, the elastic element remaining taut after striking the striking portion may achieve an accurate acoustic signal, since the lack of tension reliably prevents the striking portion from striking the striking portion multiple times.
[0035] Optionally, the actuating element is surrounded by a housing, and a resilient element is arranged between the actuating element and the housing. This arrangement facilitates movement of the resilient element relative to the housing by moving the actuating element towards the actuating part so that the abutment part disengages from the retaining part of the housing. Further optionally, the resilient element is arranged in a notch formed inside the housing. Preferably, the retaining part is thereby also arranged in the notch. The notch provides an improved guide for the resilient element.
[0036] The housing and / or the actuating element may have a hollow shape, optionally the housing and / or the actuating element have a substantially hollow cylindrical shape, which shapes allow for a particularly space-saving design, especially in connection with the technical embodiments described herein.
[0037] The actuating element may have an actuating surface for abutting against the actuating portion. For example, if the actuating element has a substantially hollow cylindrical shape, the actuating surface for abutting against the actuating portion may be provided on a circumferential protrusion that protrudes radially from the actuating element. Optionally, after the injection is completed, the actuating surface abuts against the actuating portion, and the actuating portion abuts against the holding portion. This may prevent further movement of the actuating element within the medical injection device. This may prevent the actuating element from unintentionally interfering with another element of the medical injection device.
[0038] The acoustic signal may have an acoustic pressure of at least 30 dB, optionally at least 60 dB, further optionally at least 80 dB, and further optionally at least 100 dB. These values have been proven to allow for sufficient volume of the acoustic signal for various applications. The acoustic pressure may be affected, for example, by the selected material and / or the selected preload.
[0039] The accompanying drawings are briefly described below. [Brief explanation of the drawings]
[0040] [Figure 1] FIG. 1 illustrates a portion of a medical injection device according to the present invention prior to generating an acoustic signal. [Figure 2] FIG. 2 is a detailed view of FIG. [Figure 3] FIG. 10 illustrates a portion of the medical injection device after generating an acoustic signal. [Figure 4] FIG. 4 is a detailed view of FIG. 3. DETAILED DESCRIPTION OF THE INVENTION
[0041] As shown in Figures 1 to 4, medical injection device 1 includes a housing 10 having a holding portion 12, an actuating element 20 movably disposed within housing 10, and a resilient element 30 movably disposed within housing 10. Resilient element 30 includes an actuating portion 32, a striking portion 34, and an abutting portion 36. Retaining portion 12 is integrally formed with a portion of housing 10. The illustrated medical injection device 1 is configured to generate an acoustic signal when the injection process is complete, i.e., when the substance has been completely expelled from medical injection device 1.
[0042] Furthermore, although it is not explicitly shown whether the injection process has started, a person skilled in the art will understand, based on a comparison of Figures 2 and 4, that in the initial state of the medical injection device 1, before the injection process has started, a preload is applied to the elastic element 30. In particular, in the initial state, the abutment portion 36 is in compressive engagement with the holding portion 12. This maintains the preload on the elastic element 30.
[0043] 2 and 4, the resilient element 30 is configured to move relative to the housing 10 by moving the actuating element 20 toward the actuating portion 32, such that upon movement, the abutment portion 36 disengages from the holding portion 12 and the preloaded extension of the resilient element 30 causes the striking portion 34 to strike the striking portion 22 of the medical injection device 1, thereby generating an acoustic signal. The striking portion 22 forms part of the actuating element 20. As shown, movement of the actuating element 20 is achieved by relaxation of the stress of a coil spring, although other means for achieving this movement are contemplated.
[0044] The elastic element 30 has an elongated shape, and a longitudinal axis 38 of the elastic element 30 is substantially parallel to the longitudinal axis 2 of the medical injection device 1. Furthermore, the elastic element 30 and the actuation element 20 are configured to move relative to the housing 10 along a direction that is substantially parallel to the longitudinal axis 2 of the medical injection device 1. More specifically, the elastic element 30 and the actuation element 20 are configured to move relative to the housing 10 in the injection direction 5. Furthermore, the elastic element 30 is configured such that the abutment portion 36 disengages from the holding portion 12 when the elastic element 30 moves relative to the housing 10 in the injection direction 5.
[0045] 2, the elastic element 30 has a bent portion 39 forming a first end 39 of the elastic element 30, whereby in an initial state, the bent portion 39 has a bent angle in the range of 180° to 190°. Furthermore, the elastic element 30 has a sliding portion 31 that is in sliding contact with the housing 10, and the sliding portion 31 is in substantial surface contact with the housing 10. Furthermore, the striking portion 34 is adjacent to the abutting portion 36.
[0046] 1-4, the elastic element 30 is configured such that the abutment portion 36 moves in a direction substantially perpendicular to the longitudinal axis 2 of the medical injection device 1 after the abutment portion 36 disengages from the holding portion 12. In particular, the abutment portion 36 moves towards the longitudinal axis 2 of the medical injection device 1.
[0047] As shown in FIG. 4, after striking the striking portion 34 against the striking-receiving portion 22, the striking portion 34 abuts against the striking-receiving portion 22, and therefore the elastic element 30 remains taut.
[0048] FIG. 4 further shows that the actuating element 20 has an actuating surface 24 for abutting against the actuating portion 32, and that when the injection is completed, the actuating surface 24 abuts against the actuating portion 32, which in turn abuts against the holding portion 12.
[0049] The actuating element 20, which has a substantially hollow cylindrical shape, is surrounded by the housing 10, which also has a substantially hollow cylindrical shape, so that the elastic element 30 is located between the actuating element 20 and the housing 10, i.e., in the recess 14 formed on the inside of the housing 10. [Explanation of symbols]
[0050] 1 Medical injection device 2. Longitudinal axis of the medical injection device 5 Injection direction 10. Housing 12 Holding part 14 Notch 20 Actuating Elements 22 Impact receiving part 24 Working Surface 30 Elastic Elements 31 Sliding part 32 Working parts 34 Striking part 36 Contact part 38 longitudinal axis of elastic element 39 First end / bend
Claims
1. A medical injection device (1), comprising: a housing (10) having a holding portion (12); an actuating element (20) movably disposed within said housing (10); a resilient element (30) movably disposed within said housing (10); Equipped with In the initial state of the medical injection device (1), a preload is applied to the elastic element (30), and the elastic element (30) an actuating part (32); a striking portion (34); an abutment portion (36) compressively engaging the holding portion (12) in the initial state; Equipped with The elastic element (30) is configured to move relative to the housing (10) by moving the actuating element (20) toward the actuating portion (32), and upon movement, the abutment portion (36) disengages from the holding portion (12) and the stretching of the preloaded elastic element (30) causes the striking portion (34) to strike against a striking receiving portion (22) of the medical injection device (1), thereby generating an acoustic signal.
2. 2. The medical injection device (1) according to claim 1, wherein said elastic element (30) is a metal element, optionally said elastic element (30) consisting of a bent sheet metal.
3. 3. The medical injection device (1) according to claim 1 or 2, wherein the elastic element (30) has an elongated shape and the longitudinal axis (38) of the elastic element (30) is substantially parallel to the longitudinal axis (2) of the medical injection device (1).
4. 4. The medical injection device (1) according to any one of claims 1 to 3, wherein the elastic element (30) and / or the actuating element (20) are configured to move relative to the housing (10) along a direction substantially parallel to the longitudinal axis (2) of the medical injection device (1), and optionally the elastic element (30) and / or the actuating element (20) are configured to move relative to the housing (10) in an injection direction (5).
5. 5. The medical injection device (1) according to any one of claims 1 to 4, wherein the elastic element (30) is configured such that the abutment portion (36) disengages from the holding portion (12) when the elastic element (30) moves relative to the housing (10) in the injection direction.
6. 6. The medical injection device (1) according to any one of claims 1 to 5, wherein the elastic element (30) comprises a bent portion (39) forming a first end (39) of the elastic element (30), and optionally, in the initial state, the bent portion (39) has a bent angle in the range of 160° to 210°, further optionally in the range of 170° to 200°, further optionally in the range of 180° to 190°.
7. 7. The medical injection device (1) according to any one of claims 1 to 6, wherein the elastic element (30) is configured such that after the abutment portion (36) disengages from the holding portion (12), the abutment portion (36) moves in a direction substantially perpendicular to the longitudinal axis (2) of the medical injection device (1), and optionally the abutment portion (36) moves towards the longitudinal axis (2) of the medical injection device (1).
8. 8. The medical injection device (1) according to any one of claims 1 to 7, wherein the striking portion (34) is adjacent to the abutment portion (36).
9. 9. The medical injection device (1) according to any one of claims 1 to 8, wherein the elastic element (30) has a sliding portion (31) that is in sliding contact with the housing (10), and optionally the sliding portion (31) is in substantial surface contact with the housing (10).
10. 10. The medical injection device (1) according to any one of the preceding claims, wherein the striking portion (22) forms part of the actuating element (20).
11. 11. The medical injection device (1) according to any one of claims 1 to 10, wherein the striking portion (34) abuts against the striking receiving portion (22) after striking the striking receiving portion (22), optionally so that the elastic element (30) remains taut.
12. 12. The medical injection device (1) according to any one of claims 1 to 11, wherein the actuating element (20) is surrounded by the housing (10), and the elastic element (30) is arranged between the actuating element (20) and the housing (10), and optionally, the elastic element (30) is arranged in a notch (14) formed in the housing (10).
13. 13. The medical injection device (1) according to any one of claims 1 to 12, wherein the housing (10) and / or the actuating element (20) have a hollow shape, optionally the housing (10) and / or the actuating element (20) have a substantially hollow cylindrical shape.
14. 14. The medical injection device (1) of any one of claims 1 to 13, wherein the actuating element (20) has an actuating surface (24) for abutting against the actuating portion (32), and optionally, in a state after the injection is completed, the actuating surface (24) abuts against the actuating portion (32), and the actuating portion (32) abuts against the holding portion (12).
15. 15. The medical injection device (1) of any one of claims 1 to 14, wherein the acoustic signal has an acoustic pressure of at least 30 dB, optionally at least 60 dB, further optionally at least 80 dB, and further optionally at least 100 dB.