Needle assembly with propellant actuated needle shield

Abstract

In the field of medical sharp instruments, particularly in the field of subcutaneous injection needles, an improved needle assembly is needed. A needle assembly (10, 80, 100, 110, 120, 130) for engagement with a syringe (58, 90) having an elongate hollow syringe body (56) within which a plunger (34, 88) is slidably received includes a needle assembly body (12) having a hypodermic needle (14) coupled with the needle assembly body to extend from a distal end (16) of the needle assembly body. The needle assembly (10, 80, 100, 110, 120, 130) also includes an actuator valve (18, 132) movably received within the needle assembly body (12) and formed to define a propellant storage volume (22, 122). The actuator valve (18, 132) is movable between a closed position, in which propellant is held under pressure in the propellant storage volume (22, 122), and an open position, in which propellant is released from the propellant storage volume to shield the needle (14).

Description

Technical Field

[0001] The present invention relates to a needle assembly for engagement with a syringe, a method of using such a needle assembly, and an injection device including such a needle assembly. Background Technology

[0002] Sharp objects contaminated with the blood of an infected person, especially hypodermic needles, can transmit more than 20 diseases, including hepatitis B, hepatitis C, and human immunodeficiency virus (HIV). Because of this risk of transmission, needlestick injuries cause anxiety and stress for thousands of victims. Summary of the Invention

[0003] According to a first aspect of the invention, a needle assembly is provided for engagement with a syringe having an elongated hollow syringe body, wherein a plunger is slidably received within the syringe body, the needle assembly comprising:

[0004] A needle assembly body having a hypodermic needle connected to the needle assembly body and extending from a distal end of the needle assembly body; and

[0005] An actuator valve, movably received within the needle assembly body, is configured to define a propellant storage volume.

[0006] The actuator valve can move between a closed position and an open position. In the closed position, the propellant is held in the propellant storage volume under pressure. In the open position, the propellant is released from the propellant storage volume to allow the needle to be shielded.

[0007] Selectively shielding the needle, i.e. shielding the needle after the actuator valve has moved to its open position, is highly advantageous because enclosing or sealing the needle in this way helps prevent needlestick injuries, for example, after using an injection device in which the needle assembly of the present invention is part.

[0008] Meanwhile, actuator valves of the aforementioned types, particularly those using pressurized propellants to shield the needle, ideally provide a suitable prime mover for achieving this shielding. However, this prime mover gradually increases from an initial low level to higher levels, thus applying a mild, somewhat resilient thrust. This contrasts with individual mechanical actuators such as springs, which typically have less tolerant operating modes because they frequently transition from high to low initial forces. Such mechanical actuators are also prone to mechanical creep over time, causing them to become less efficient and potentially unreliable over time.

[0009] Furthermore, providing a gradually increasing motive force reduces the likelihood of any residual medication unintentionally shifting from the internal conduit of the needle during use as the needle is shielded, i.e., reducing the risk of medication "splashing" when the shielding element transitions to its shielding configuration, a risk that tends to occur in devices with mechanical actuators that typically cause sudden movement and have a higher rate of acceleration (e.g., retractable needle devices).

[0010] The actuator valve of the present invention also allows the applied prime mover to be adjusted at any time by changing the stored enthalpy (i.e., initial internal energy) of the pressurized propellant in order to achieve masking in terms of overall amplitude and application rate.

[0011] In addition, an actuator valve is formed to limit the propellant storage volume to allow adjustment of the propellant storage volume size according to the requirements of the needle assembly and / or the characteristics of the propellant thus held.

[0012] Preferably, the actuator valve itself limits the propellant storage volume.

[0013] By limiting the propellant storage volume by the actuator valve itself, the number of seal formations required to maintain the sealing integrity of the propellant storage volume is restricted, thus advantageously providing a corresponding reduction in the risk of leakage via one or more such formations.

[0014] Furthermore, the reduction in the number of seal formations also ideally reduces the amount of force required to move (i.e. operate) the actuator valve to resist the resistance that such seal formations may exert.

[0015] Optionally, the actuator valve includes an external support forming portion having a hollow interior that defines a propellant storage volume.

[0016] This arrangement allows the actuator valve to provide the aforementioned benefits while being easy to manufacture, and the propellant storage volume can be pre-filled once the needle assembly of the present invention is assembled.

[0017] The actuator valve can mate with the needle assembly body to define a propellant storage volume therebetween.

[0018] This arrangement provides further options for adjusting the size of the propellant storage volume.

[0019] Preferably, the actuator valve includes a first and a second seal formation spaced apart axially, forming a propellant storage volume therebetween.

[0020] The propellant storage volume can have a ring shape.

[0021] These features provide further sizing options, while also helping to ensure that propellant can be easily released from the propellant storage volume, for example, when the actuator valve moves to its open position.

[0022] Optionally, the actuator valve defines an abutment forming portion, and the syringe plunger can abut against the abutment forming portion during use to move the actuator valve from its closed position to its open position.

[0023] An actuator valve with such an abutment formation advantageously allows, in use, the continuous insertion of the plunger into the syringe body of a syringe that engages with the needle assembly of the present invention to be converted into the opening of the actuator valve, thereby releasing propellant from the propellant storage volume and ultimately shielding the needle. Therefore, such an actuator valve ideally provides the option of continuous operation using, for example, an injection device in which the needle assembly is incorporated, such as continuously injecting medication into a receptor to influence the operation (i.e., opening) of the actuator valve, thereby automatically shielding the needle.

[0024] In a preferred embodiment of the invention, the movement of the actuator valve into the open position causes the propellant storage volume to be in fluid communication with the vent duct, which is configured to guide the released propellant flow in one or both of the distal and proximal axial directions.

[0025] The actuator valve moves to the open position to fluidly communicate the propellant storage volume with the first vent duct, which extends in the proximal axial direction and is configured to guide the released propellant flow in the proximal axial direction.

[0026] The actuator valve moves to the open position to fluidly communicate the propellant storage volume with the second vent duct, which extends axially at the distal end and is configured to guide the released propellant flow in the axial direction at the distal end.

[0027] The ability to guide the released propellant flow in the distal axial direction ideally provides a first motive force that can extend over the needle, such as a shield, to achieve the desired shielding, while the ability to guide the released propellant flow in the proximal axial direction ideally generates a second motive force that is substantially opposite to the first motive force, which can retract the needle back into the needle assembly body, thereby shielding the needle by the assembly body.

[0028] Preferably, the second ventilation conduit extends through the needle assembly body.

[0029] This arrangement ideally achieves the necessary guidance of the propellant flow along the distal axial direction.

[0030] In another preferred embodiment of the invention, the second venting duct is further configured to be in fluid communication with the first venting duct, thereby, when the actuator valve is moved to the open position, the propellant storage volume is arranged to be in fluid communication with the first venting duct via the second venting duct.

[0031] Optionally, the first ventilation duct also extends in the distal axial direction, thereby being configured to guide the released propellant flow in both the proximal and distal axial directions when the actuator valve is moved to its open position.

[0032] Each of the above-described configurations is advantageously able to provide a first and a second driving force, thus advantageously resulting in the option of using, for example, a combination of a cover extension and a needle retraction to achieve needle shielding.

[0033] Preferably, when the actuator valve is moved to the first open position, the propellant storage volume is arranged in fluid communication with one of the first and second vent ducts, and when the actuator valve is moved to the second open position, the propellant storage volume is arranged in fluid communication with both the first and second vent ducts simultaneously.

[0034] The first and second open positions of the actuator valve ideally provide a choice to initiate one shielding mode, such as shield extension or needle retraction, before both shielding modes occur, thus allowing adjustment of different types of shielding.

[0035] In another preferred embodiment of the invention, a first venting conduit extends between the actuator valve and the needle and terminates at a proximal end, whereby a first drive member securely fixed to the needle seals against the proximal end, thereby acting on the first drive member with proximal axial flow of propellant released into the first venting conduit, causing the first drive member and the needle securely fixed to the first drive member to move in the proximal axial direction.

[0036] It is ideal to drive the needle in this way along the proximal axial direction because it allows the needle to retract into the needle assembly body.

[0037] Meanwhile, the first drive member, configured to be sealed adjacent to the proximal end of the first ventilation duct, advantageously provides a method for converting the propellant flow released into the first ventilation duct into the aforementioned ideal motion of the needle in the proximal axial direction.

[0038] The first ventilation conduit may be defined by a hollow conduit member, which is securely fixed at its distal end to the needle assembly body, and the needle may move axially within the hollow conduit.

[0039] The inclusion of such a hollow conduit component readily provides a conduit extending in a proximal axial direction, thus enabling advantageous guidance of the released propellant flow in this proximal axial direction.

[0040] Preferably, the hollow conduit member has a first opening formed therein to define an inlet orifice leading to the first ventilation conduit.

[0041] Providing an inlet port for the first venting duct ideally allows for the selective introduction of released propellant into the first venting duct, for example, when the actuator valve moves toward the open position.

[0042] Optionally, the actuator valve may slide on the conduit member, and the first drive member is spaced apart on the proximal side of the needle to define a proximal needle portion, whereby movement of the actuator valve toward the open position also exposes the proximal needle portion beyond the actuator valve.

[0043] This configuration advantageously allows the proximal needle portion to be exposed during operation of the actuator valve, thus providing the option to make the proximal needle portion assist the function of the needle assembly (e.g., continuous movement of the needle in the proximal axial direction).

[0044] In another preferred embodiment of the invention, the proximal needle portion cooperates with a second drive member configured to enclose a hollow syringe body of the syringe that engages with the needle assembly in use, thereby, after the initial movement of the first drive member and the needle in the proximal axial direction, the propellant guided to flow through the first conduit in the proximal direction also acts on the second drive member so that the movement of the needle in the proximal axial direction continues.

[0045] The inclusion of a second drive member helps ensure that all propellant released into the first ventilation duct and guided to flow along the proximal axial direction can be utilized to move the needle in the same proximal axial direction.

[0046] The needle assembly can engage with a syringe having a modified plunger configured to carry a second drive member and securely fasten the second drive member to the proximal needle portion before abutting with the abutment formation of the actuator valve.

[0047] Providing this modified plunger helps ensure that the second drive component is firmly secured to the proximal needle portion only before it assists in the proximal axial movement of the needle.

[0048] Preferably, the second drive member and the modified plunger include mutually mating formations to selectively fix the second drive member and the modified plunger to each other.

[0049] This forming part advantageously facilitates the required bearing of the second drive member by modifying the plunger, and, when necessary, fixes it to the proximal needle portion.

[0050] Optionally, at least one of the mating forming parts is elastically deformable.

[0051] The presence of at least one elastically deformable mating portion advantageously allows the second drive member to selectively separate from the modification plunger, for example, when the second drive member is used to move the needle in a proximal axial direction, but it is not desired to move the modification plunger in such a direction.

[0052] In another preferred embodiment of the invention, the released propellant, which is guided to flow in the distal axial direction, is further guided into a foldable chamber that is sealed and fixed to the needle assembly body, thereby releasing the propellant from the propellant storage volume into the foldable chamber, causing the chamber to expand in the distal axial direction.

[0053] This expansion of the chamber in the distal axial direction is ideal because it allows the chamber to extend at least partially over the needle, i.e., to shield the needle.

[0054] Therefore, this foldable chamber advantageously provides a method for converting the flow of propellant along the distal axial direction into the aforementioned ideal motion of the chamber along the distal axial direction.

[0055] The foldable chamber is sealed between the needle assembly body and the protective cover assembly, thereby allowing propellant to be released from the propellant storage volume into the foldable chamber via the second venting conduit, causing the chamber to expand in the distal axial direction and pushing the protective cover assembly across the needle in the distal axial direction.

[0056] The movement of the protective assembly on the needle, that is, completely enclosing and thereby shielding the needle, provides further protection, such as preventing needlestick injuries.

[0057] According to a second aspect of the invention, a method for a needle assembly as described above is provided, comprising the step of moving an actuator valve between a closed position and an open position, wherein in the closed position, propellant is held under pressure in a propellant storage volume, and in the open position, propellant is released from the propellant storage volume to shield the needle.

[0058] According to a third aspect of the invention, an injection device is provided, which includes the needle assembly as described above.

[0059] The second and third aspects of the invention share the benefits of the corresponding features of the components of the invention.

[0060] It should be understood that, unless otherwise stated, the use of terms such as “first” and “second” in this patent specification is intended only to help distinguish similar features and is not intended to indicate the relative importance of one feature to another.

[0061] Within the scope of this application, it is expressly intended that the various aspects, embodiments, examples, and alternatives listed in the foregoing paragraphs, as well as the claims and / or the following description and drawings, particularly their individual features, may be employed independently or in any combination. That is, all embodiments and all features of any embodiment may be combined in any manner and / or combination, unless these features are incompatible. The applicant reserves the right to amend any previously filed claims accordingly or to file any new claims, including the right to amend any previously filed claims to make them subordinate to and / or include features of any other claim, even if not originally claimed in that manner. Attached Figure Description

[0062] Preferred embodiments of the invention will now be briefly described with reference to the following accompanying drawings, by way of non-limiting examples, in which:

[0063] Figure 1 A perspective view of a needle assembly according to a first embodiment of the present invention is shown;

[0064] Figure 2 The following is shown as part of an injection device according to another embodiment of the present invention. Figure 1 A schematic cross-sectional view of the needle assembly shown;

[0065] Figures 3(a) to 3(e) show Figure 1 An enlarged schematic cross-sectional view of a portion of the needle assembly shown;

[0066] Figures 4(a) to 4(c) show enlarged schematic cross-sectional views of a portion of a needle assembly according to a second embodiment of the present invention;

[0067] Figures 5(a) to 5(d) show enlarged schematic cross-sectional views of a portion of a needle assembly according to a third embodiment of the present invention;

[0068] Figures 6(a) to 6(d) show enlarged schematic cross-sectional views of a portion of a needle assembly according to a fourth embodiment of the present invention;

[0069] Figures 7(a) to 7(e) show enlarged schematic cross-sectional views of a portion of a needle assembly according to a fifth embodiment of the present invention;

[0070] Figures 8(a) and 8(b) show schematic cross-sectional views of components of a needle assembly according to a sixth embodiment of the present invention; and

[0071] Figure 9 A partial exploded view of the actuator valve that forms part of the needle assembly shown in Figures 8(a) and 8(b) is shown. Detailed Implementation

[0072] The needle assembly according to the first embodiment of the present invention is generally indicated by reference numeral 10, such as... Figure 1 as well as Figure 2 As shown in Figures 3(a) to 3(e).

[0073] The first needle assembly 10 includes a needle assembly body 12 having a hypodermal injection needle 14 (not all shown in Figures 3(a) to 3(e)) connected thereto, extending from the distal end 16 of the needle assembly body 12 along a distal axial direction A. D extend.

[0074] The needle assembly 10 also includes a first actuator valve 18, which is movably received within the needle assembly body 12, and more specifically, slidably received within the hollow, generally annular interior 20 of the needle assembly body 12, but is not required to be so; other shapes of interiors and only partially hollow interiors are also possible.

[0075] In any case, the actuator valve 18 cooperates with the needle assembly body 12 (i.e., its hollow interior 20) to define a propellant storage volume 22 located in the actuator valve 18 and the needle assembly body 12.

[0076] More specifically, the actuator valve 18 includes a first sealing portion 24 and a second sealing portion 26 spaced axially apart, forming a propellant storage volume 22 between them. Given the annular shape of the hollow interior 20 of the needle assembly body 12, the first sealing portion 24 and the second sealing portion 26 are generally annular to seal against this hollow interior 20, and the resulting propellant storage volume 22 similarly has an annular shape. However, other shapes of the propellant storage volume are also possible.

[0077] Preferably, each sealing portion 24, 26 is formed of a relatively soft, elastically deformable material (such as a natural or synthetic elastomer) (or includes elements formed thereof, such as O-rings or sheaths 28)), while the needle assembly body 12, or at least the portion defining the hollow interior of the actuator valve 18, is formed of or includes a harder, less deformable material. In this case, the internal support portion 30 of the actuator valve 18 may be formed of or include a similar less deformable material.

[0078] In other embodiments, the needle assembly body or at least the portion of its hollow interior where the actuator valve is located may be formed of or include a relatively soft, elastically deformable material, and each seal formation may be formed of a harder, more difficult-to-deform material (or include elements formed of that material).

[0079] In addition to the above, actuator valve 18 can be in the closed position (e.g. Figure 2The needle 14 moves between the closed position (as shown in Figure 3(a)) and the open position (as shown in Figure 3(d)). In the closed position, the propellant (not shown) is held under pressure in the propellant storage volume 22. In the open position, the propellant is released from the propellant storage volume 22 so that the needle 14 is shielded (covered), i.e., completely enclosed or sealed, as shown in Figure 3(e), and will also be described in detail below.

[0080] Preferably, the propellant is a gas, such as hydrofluorocarbons like Solkane®, more specifically Solkane® 227ea, but other propellants may also be used. Furthermore, when maintained in the propellant storage volume 22 under pressure (e.g., at ambient or room temperature), the propellant (e.g., a gas) may be in a liquid or gas phase.

[0081] Furthermore, the actuator valve 18 defines an abutment forming portion 32, which, in use, allows the first syringe plunger 34 to abut against in order to move the actuator valve 18 from its closed position to its open position, as will be described in more detail below.

[0082] The first needle assembly 10 also includes a first ventilation conduit 36, which is located in the proximal axial direction A P Extending upwards and configured to be in the same proximal axial direction A P The propellant stream is guided and released from above.

[0083] More specifically, a first ventilator 36 extends between the actuator valve 18 and the needle 14 and terminates at a proximal end 38. More specifically, in the illustrated embodiment, the first ventilator 36 is defined by a hollow conduit member 40, which is securely attached at a distal end 42 to the needle assembly body 12, in which the needle 14 can move axially, for example, at least in the proximal axial direction A. P Movement. In addition, the hollow conduit member 40 has a first opening 44 formed therein to define an inlet orifice 46 leading to the first ventilation conduit 36.

[0084] However, other types and constructions of the first ventilation duct are also possible.

[0085] Returning to the illustrated embodiment, the first drive member 48 is securely attached to the needle 14 and spaced apart inside the proximal end 50 of the needle 14 to define the proximal needle portion 52. The first drive member 48 is sealingly abutted against the proximal end 38 of the first venting conduit 36 ​​and is selectively held there by the actuator valve 18, more specifically, in the illustrated embodiment, by the relatively soft, elastically deformable outer skin 28 of the actuator valve.

[0086] The proximal needle portion 52 can cooperate with the second drive member 54, which is configured to close (i.e., fluid seal) the hollow syringe body 56 of the first syringe 58. In use, the needle assembly 10 engages with the hollow syringe body 56.

[0087] More specifically, the first syringe 58 has a first modified plunger 34 configured to carry the second drive member 54. More specifically, the first modified plunger 34 and the second drive member 54 include mating portions 60, 62 that selectively secure the second drive member 54 and the first plunger 34 to each other. Each mating portion 60, 62 is elastically deformable, but not necessarily, and in the illustrated embodiment takes the form of corresponding chamfered barbs 64, 66 that can slide against each other during such elastic deformation. However, other types of mating portions are also possible.

[0088] Figures 3(a) through 3(e) schematically illustrate the combined use of the first needle assembly 10 with a first syringe 58 having a syringe body 56 and a first modified plunger 34 (to define the injection device 150 according to an embodiment of the invention), and are described below.

[0089] Before using the first injection device 150, for example before injecting a drug (not shown) into the recipient using the injection device 150, the actuator valve 18 is in its closed position, the propellant (not shown) is maintained under pressure in the propellant storage volume 22, and the first modified plunger 34 is positioned spaced apart from the actuator valve 18, such as Figure 2 As shown in Figure 3(a).

[0090] When medication needs to be dispensed from the injection device 150, a user, such as a medical professional or other healthcare professional, dispenses it in a known manner along the distal axial direction A. D The first plunger 34 is moved to drive medication (not shown) out of the hollow syringe body 56 through the needle 14. The first plunger 34 is positioned axially at the distal end. D This movement causes the first plunger 34 to abut against the abutment formation 32 of the actuator valve 18, as shown, for example, in FIG3(b).

[0091] Subsequently, as shown in Figure 3(c), the first plunger 34 is in the distal axial direction A D Further movement of the actuator valve 18 relative to the needle assembly body 12 begins to move the actuator valve 18 toward its open position.

[0092] This initial movement of actuator valve 18 toward its open position also causes actuator valve 18 to move relative to conduit member 40, more specifically, to slide actuator valve 18 on conduit member 40, which pushes first drive member 48 along proximal axial direction A. P The needle 14 passes through the actuator valve 18, and more specifically through the soft outer sheath 28 of the actuator valve 18, so that the proximal needle portion 52 is exposed beyond the actuator valve 18. Furthermore, when the proximal needle portion 52 is exposed beyond the actuator valve 18, it is driven to engage with the second drive member 54, thereby firmly securing the needle 14 and the second drive member 54 to each other.

[0093] Subsequently, the first plunger 34 moves in the distal axial direction A D Further movement of the actuator valve 18 will move it to its open position, as shown in Figure 3(d).

[0094] This movement of actuator valve 18 to its open position fluidly connects propellant storage volume 22 to the first vent duct 36, i.e., via a connecting duct 68 formed in the support forming portion 30 of actuator valve 18 and an inlet orifice 46 formed in the duct member 40, so that propellant (highlighted in FIG. 3(d)) is released from propellant storage volume 22 and guided along the first vent duct 36 toward its proximal end 38 in the proximal axial direction A. P It flows upward and contacts the first driving member 48.

[0095] At the same time, the actuator valve 18 moves to its open position to separate the second drive member 54 from the first modified plunger 34, i.e., by forcing the deformable chamfered hooks 64, 66 to overlap each other.

[0096] Therefore, as shown in Figure 3(e), the released propellant (highlighted) thus acts on the first drive member 48 to propel it in the proximal axial direction A. P The first drive member 48 is pushed upward (i.e. moved), thereby causing the needle 14 fixed on the first drive member 48 to move in the same proximal axial direction A. P Initial move.

[0097] Furthermore, once the first drive member 48 and the needle 14 are in the proximal axial direction A P Having undergone this initial motion, and with the propellant having escaped past the first drive member 48 and passed the proximal end 38 of the first vent duct 36, the propellant will then act additionally on the second drive member 54 to continue the needle 14 in the proximal axial direction A. P The movement of the needle 14 within the needle assembly 10 and the associated syringe body 56 completes the desired degree of retraction (not shown).

[0098] The needle assembly according to the second embodiment of the present invention is generally indicated by reference numeral 80, as shown in Figures 4(a) to 4(c).

[0099] The second needle assembly 80 shares many features with the first needle assembly 10, and these features are identified by the same reference numerals.

[0100] However, the second needle assembly 80 differs from the first needle assembly 10 in that the second needle assembly 80 does not include the first ventilation tube, but instead includes a distal axial direction A D The upper-extending second ventilation duct 82 is configured to direct the released propellant flow along the same distal axial direction A. D guide.

[0101] More specifically, the second ventilation conduit 82 extends through the needle assembly body 12 and guides the released propellant flow into a collapsible chamber 84 that is sealed within the needle assembly body 12. The collapsible chamber 84 may be additionally sealed between the needle assembly body 12 and the protective cover assembly (not shown).

[0102] Furthermore, the second needle assembly 80 omits the first drive member and instead includes a plug member 86, which is similarly and securely fixed to the needle 14 and spaced inside the proximal end 50 of the needle 14 to define the proximal needle portion 52, but is not used to move the needle 14 under the action of the released propellant. Instead, the plug member 86 simply closes the conduit member 40 that houses the needle 14.

[0103] Furthermore, the proximal needle portion 52 of the second needle assembly 80 can directly mate with the second modification plunger 88 of the second syringe 90. In use, the second needle assembly 80 can engage with the second modification plunger 88 to define the injection device 160 according to another embodiment of the present invention. The second modification plunger 88 differs slightly from the first modification plunger 34 in the first needle assembly 10 because the second modification plunger 88 does not carry the second drive member, but simply includes a receiving forming portion 92 for receiving the proximal needle portion 52.

[0104] The operation (i.e., use) of the second needle assembly 80 is somewhat similar to that of the first needle assembly 10, but there are also differences, as described below.

[0105] Therefore, before using the second injection device 160 where the second needle assembly 80 is located, the actuator valve 18 is also in its closed position, the propellant (not shown) is maintained under pressure in the propellant storage volume 22, and the second modified plunger 88 is separated from the actuator valve 18, as shown in FIG4(a).

[0106] Similarly, when medication needs to be dispensed from the second injection device 160, the user dispenses it along the distal axial direction A. DThe second plunger 88 is moved to drive the drug (not shown) out of the hollow syringe body 56 through the needle 14 in a known manner. The second plunger 88 is located in the distal axial direction A. D This movement causes the second plunger 88 to abut against the abutment formation 32 of the actuator valve 18, as shown, for example, in FIG4(b).

[0107] Subsequently, the second plunger 34 moves in the distal axial direction A D Further movement of the actuator valve 18 relative to the needle assembly body 12 will cause the actuator valve 18 to move toward its open position.

[0108] This initial movement of actuator valve 18 toward its open position also causes actuator valve 18 to move relative to conduit member 40, and more specifically, again causes actuator valve 8 to slide on conduit member 40, which in turn causes plug member 86 to move in the proximal axial direction A. P Pushing past the actuator valve 18, that is, pushing past the soft outer skin 28 of the actuator valve, exposes the proximal needle portion 52 beyond the actuator valve 18. Furthermore, when the proximal needle portion 52 is exposed beyond the actuator valve 18, it is received within the receiving formation 92 of the second modified plunger 88.

[0109] Subsequently, the second plunger 88 moves in the distal axial direction A D Further movement of the actuator valve 18 will move it to its open position, as shown in Figure 4(c).

[0110] This movement of actuator valve 18 to its open position fluidly connects propellant storage volume 22 with the second vent duct 82, causing propellant (highlighted in FIG. 4(c)) to be released from propellant storage volume 22 and guided along the distal axial direction A. D It flows through the second ventilation duct 82 and into the foldable chamber 84.

[0111] Propellant (highlighted) is released from propellant storage volume 22 into collapsible chamber 84, such that chamber 84 is positioned above needle 14 in the distal axial direction A. D The expansion allows the foldable chamber 84 to cover the needle 14 to the desired degree, i.e., shield it.

[0112] Furthermore, in embodiments where the foldable chamber is sealed between the needle assembly body and the protective cover assembly (not shown), the release of propellant from the propellant storage volume into the foldable chamber via a second venting conduit also causes the protective cover assembly to move in the distal axial direction A. D It is pushed onto the needle, so that the needle is shielded by the protective assembly to the desired extent.

[0113] The needle assembly according to the third embodiment of the present invention is generally indicated by reference numeral 100, as shown in Figures 5(a) to 5(d).

[0114] The third needle assembly 100 shares many features with the first needle assembly 10 and the second needle assembly 80, and these features are identified by the same reference numerals.

[0115] In this respect, the third needle assembly 100 includes both a first venting conduit 36 ​​and a second venting conduit 82, but differs from each of the first needle assembly 10 and the second needle assembly 80 in that the second venting conduit 82 is additionally arranged in fluid communication with the first venting conduit 36, such that when the actuator valve 18 is moved to its open position, for example as shown in Figures 5(c) and 5(d), the propellant storage volume 22 is in fluid communication with the first venting conduit 36 ​​via the second venting conduit 82. In the illustrated embodiment, the collapsible chamber 84 fluidly interconnects the second venting conduit 82 with the open distal end 102 of the first venting conduit 36 ​​via a conduit channel 104 formed in the needle assembly body 12. However, other arrangements of fluid interconnection are also possible.

[0116] The third needle assembly 100 can be used in conjunction with the first syringe 58 and the associated first modified plunger 34 (in order to define an injection device 170 according to another embodiment of the invention), as described below.

[0117] Before using the third injection device 170, the actuator valve 18 is once again in its closed position, and the propellant (not shown) is maintained under pressure in the propellant storage volume 22, with the first modified plunger 34 spaced apart from the actuator valve 18, as shown in FIG5(a).

[0118] The first plunger 34, for example, is used to dispense medication (not shown) from the first syringe 58 in the distal axial direction A D The movement causes the first plunger 34 to abut against the abutment forming portion 32 of the actuator valve 18, as shown in Figure 5(b).

[0119] Subsequently, the first plunger 34 moves in the distal axial direction A D Further movement of the actuator valve 18 relative to the needle assembly body 12 will cause the actuator valve 18 to move toward its open position.

[0120] This initial movement of actuator valve 18 toward its open position also causes actuator valve 18 to move relative to conduit member 40 and causes actuator valve 8 to slide on conduit member 40, which pushes first drive member 48 in the proximal axial direction A. PThe needle 14 passes through the actuator valve 18, and more specifically through the soft outer sheath 28 of the actuator valve 18, so that the proximal needle portion 52 is exposed beyond the actuator valve 18. Furthermore, when the proximal needle portion 52 is exposed beyond the actuator valve 18, it is similarly driven to engage with the second drive member 54, thereby firmly securing the needle 14 and the second drive member 54 to each other.

[0121] Subsequently, the first plunger 34 moves in the distal axial direction A D Further movement of the actuator valve 18 will move it to its open position, as shown in Figure 5(c).

[0122] This movement of actuator valve 18 to its open position puts propellant storage volume 22 into fluid communication with the second vent duct 82, and also into fluid communication with the first vent duct 36 due to the fluid interconnection provided by the collapsible chamber 84, duct passage 104 and open distal end 102.

[0123] Therefore, the propellant released from propellant storage volume 22 (highlighted in Figure 5(c)) is guided along the distal axial direction A. D The airflow flows into the collapsible chamber through the second ventilation duct 82, and along the proximal axial direction A. P The airflow flows along the first vent duct 36 toward its proximal end 38 and contacts the first drive member 48. At the same time, the actuator valve 18 moves to its open position to separate the second drive member 54 from the first modified plunger 34, i.e., by forcing the deformable chamfered hooks 64, 66 to overlap each other.

[0124] As shown in Figure 5(c), the released propellant (highlighted) thus acts on the foldable chamber 84 and the first drive member 48.

[0125] The propellant released onto the foldable chamber 84 causes the chamber 84 to move along the distal axial direction A on the needle 14. D The expansion allows the foldable chamber 84 to provide a first degree of coverage, i.e., shielding, of the needle 14.

[0126] Simultaneously, the propellant released acting on the first drive member 48 travels along the proximal axial direction A. P Pushing (i.e. moving) the first drive member 48, and consequently causing the needle 14, which is securely fixed to the first drive member 148, to move along the same proximal axial direction A. P Initial movement.

[0127] Furthermore, once the first drive member 48 and the needle 14 are in the proximal axial direction A PAfter this initial motion, and with the propellant having escaped through the first drive member 48 and passed the proximal end 38 of the first vent duct 36, the propellant will then act additionally on the second drive member 54 to continue the needle 14 in the proximal axial direction A. P The movement of the needle 14 within the needle assembly 100 and the associated syringe body 56 (as shown in FIG5(d)) completes a second desired degree of retraction (not shown).

[0128] Therefore, the first degree of shielding of the needle 14 caused by the release of the propellant expanding the foldable chamber 84, and the second degree of retraction of the needle 14 caused by the release of the propellant acting on the first drive member 48 and then on the second drive member 54, result in the needle 14 being completely enclosed, i.e., completely shielded (not shown).

[0129] As shown in Figures 6(a) to 6(d), the needle assembly according to the fourth embodiment of the present invention is generally indicated by reference numeral 110.

[0130] The fourth pin assembly 110 has many similarities to the third pin assembly 100, and these similar features are identified by the same reference numerals.

[0131] More specifically, the fourth pin assembly 110 is similar to the third pin assembly 100, and is capable of selectively moving along the distal axial direction A. D and proximal axial direction A P The propellant flow is guided, but the fourth needle assembly 110 only includes the first ventilation duct 36.

[0132] Conversely, the first ventilation conduit 36 ​​in the fourth needle assembly 110 also extends along the distal axial direction A D The extension causes it to be configured such that when the actuator valve 18 moves to its open position, it simultaneously moves along the proximal axial direction A. D and distal axial direction A P Guide the release of propellant streams.

[0133] In the illustrated embodiment, this configuration is achieved by extending the first ventilation conduit 36 ​​distally beyond the opening 44 in the conduit member 40, that is, beyond the inlet orifice 46 to the first ventilation conduit 36, to its open distal end 102, and then discharging into the foldable chamber 84 via the conduit passage 104 in the needle assembly body 12.

[0134] Therefore, the inlet orifice 46 is fluidly connected to the first drive member 48 and the foldable chamber 84. However, other fluid interconnection arrangements are also possible.

[0135] The fourth needle assembly 110 can be similarly used in conjunction with the first syringe 58 and the associated first modified plunger 34 (in order to define an injection device 180 according to another embodiment of the invention).

[0136] The fourth needle assembly 110 functions similarly to the third needle assembly 100, such that before the fourth injection device 180 is used, the actuator valve 18 is again in its closed position, the propellant (not shown) is maintained under pressure in the propellant storage volume 22, and the first modified plunger 34 is spaced apart from the actuator valve 18, as shown in FIG6(a).

[0137] The first plunger 34, for example, is used to dispense medication (not shown) from the first syringe 58 in the distal axial direction A D The movement causes the first plunger 34 to abut against the abutment forming portion 32 of the actuator valve 18, as shown, for example, in FIG6(b).

[0138] Subsequently, the first plunger 34 moves in the distal axial direction A D Further movement of the actuator valve 18 relative to the needle assembly body 12 will cause the actuator valve 18 to move toward its open position.

[0139] This initial movement of actuator valve 18 toward its open position also causes actuator valve 18 to move relative to conduit member 40 and causes actuator valve 8 to slide on conduit member 40, which pushes first drive member 48 in the proximal axial direction A. P The needle 14 passes through the actuator valve 18, and more specifically through the soft outer sheath 28 of the actuator valve 18, so that the proximal needle portion 52 is exposed beyond the actuator valve 18. Furthermore, when the proximal needle portion 52 is exposed beyond the actuator valve 18, it is similarly driven to engage with the second drive member 54, thereby firmly securing the needle 14 and the second drive member 54 to each other.

[0140] Subsequently, the first plunger 34 moves in the distal axial direction A D Further movement of the actuator valve 18 will move it to its open position, as shown in Figure 6(c).

[0141] This movement of actuator valve 18 to its open position puts propellant storage volume 22 into fluid communication with the first vent duct 36, i.e., through the connecting conduit 68 in actuator valve 18 and the inlet orifice 46 in the first vent duct 36, and simultaneously into fluid communication with the foldable chamber 84 due to the fluid interconnection with the foldable chamber 84 provided by the duct passage 104 and the open distal end 102 of the first vent duct 36.

[0142] Therefore, the propellant released from propellant storage volume 22 (highlighted in Figure 6(c)) is guided along the proximal axial direction A.P Flowing along the first ventilation duct 36 toward its proximal end 38 and contacting the first drive member 48, and along the distal axial direction A D The airflow flows into the collapsible chamber 84 through the open distal end 102 of the first vent duct 36 and the duct passage 104. Simultaneously, the actuator valve 18 moves to its open position, similarly separating the second drive member 54 from the first modified plunger 34, i.e., by forcing the deformable chamfered hooks 64, 66 to overlap each other.

[0143] Therefore, as shown in Figure 6(c), the released propellant (highlighted) thus acts on the first drive member 48 and the foldable chamber 84.

[0144] The propellant released acting on the first drive member 48 in the proximal axial direction A P The first drive member 48 is pushed upward (i.e. moved), thereby causing the needle 14, which is securely fixed to the first drive member 148, to move in the same proximal axial direction A. P Initial movement.

[0145] Furthermore, once the first drive member 48 and the needle 14 are in the proximal axial direction A P After this initial motion, and with the propellant having escaped through the first drive member 48 and passed the proximal end 38 of the first vent duct 36, the propellant will then act additionally on the second drive member 54 to continue the needle 14 in the proximal axial direction A. P The movement of the needle 14 within the needle assembly 110 and the associated syringe body 56 (as shown in FIG. 6(d)) completes a first desired degree of retraction (not shown).

[0146] Simultaneously, the released propellant acting on the foldable chamber 84 causes the chamber 84 to move along the distal axial direction A on the needle 14. D The expansion allows the foldable chamber 84 to provide a first degree of coverage, i.e., shielding, of the needle 14.

[0147] Therefore, similar to the third needle assembly 100, the first degree of retraction of the needle 14 caused by the released propellant acting on the first drive member 48 and then on the second drive member 54, and the second degree of shielding of the needle 14 caused by the released propellant acting to expand the foldable chamber 84, similarly result in the fourth needle assembly 110 in which the needle 14 is completely enclosed (i.e. completely shielded (not shown)).

[0148] The needle assembly according to the fifth embodiment of the present invention is generally indicated by reference numeral 120, as shown in Figures 7(a) to 7(e).

[0149] The fifth needle assembly 110 shares features with each of the first needle assembly 10 and the second needle assembly 80, and these similar features are identified by the same reference numerals.

[0150] In this respect, the fifth needle assembly 120 includes a first ventilation tube 36 and a second ventilation tube 82, thus enabling selective ventilation along the distal axial direction A. D and proximal axial direction A P Guide the released propellant stream, just like each of the third needle assembly 100 and the fourth needle assembly 110.

[0151] However, in the fifth needle assembly 120, when the actuator valve 18 is moved to the first open position, the modified propellant storage volume 122 is in fluid communication with the second vent duct 82, as shown in FIG7(c), and when the actuator valve 17 is moved to the second open position (as shown in FIG8(d)), the modified propellant storage volume 112 is in fluid communication with the first vent duct 36 and the second vent duct 82.

[0152] In other embodiments of the fifth needle assembly (not shown), the propellant storage volume may be modified to initially be in fluid communication only with the first vent duct when the actuator valve moves to the first open position, and then in fluid communication with both the first and second vent ducts when the actuator valve moves to the second open position.

[0153] Returning to the fifth embodiment shown, this configuration—that is, the ability to fluidly communicate only with the second vent duct 82 in the first open position and with both the first vent duct 36 and the second vent duct 82 in the second open position—is achieved by providing a modified first seal formation 124 to the actuator valve 18. More specifically, the modified first seal formation 124 includes a tapered profile 126 that allows the modified propellant storage volume 122 to fluidly communicate with the second vent duct 82 more quickly, i.e., compared to other cases, such as with each of the second needle assembly 80, the third needle assembly 100, and the fourth needle assembly 110, in the distal axial direction A of the actuator valve 18. D This can be achieved after moving a short distance, and before fluid communication is established between the modified propellant storage volume 122 and the first exhaust channel 36 (as shown in Figure 7(c)).

[0154] Furthermore, as the actuator valve 18 continues to move axially to its second open position, for example as shown in FIG7(d), the modified first seal forming portion 124 keeps the modified propellant storage volume 122 in fluid communication with the second vent duct 82, such that when the modified propellant storage volume 122 is in fluid communication with the first vent duct 36, it is also in fluid communication with the second vent duct 82.

[0155] Therefore, the modified propellant storage volume 122 is first fluidly connected to the collapsible chamber 84, i.e., via the second vent duct 82, and then, after a delay, additionally fluidly connected to the first drive member 48, i.e., via the first vent duct 36. However, other fluid interconnection arrangements are also possible.

[0156] The fifth needle assembly 120 can be similarly used in conjunction with the first syringe 58 and the associated first modified plunger 34 (in order to define the injection device 190 according to another embodiment of the invention).

[0157] The fifth needle assembly 120 functions similarly to the first needle assembly 10 and the second needle assembly 80. Before the fifth injection device 190 is used, the actuator valve 18 is again in its closed position, and the propellant (not shown) is maintained under pressure in the improved propellant storage volume 122, with the first modified plunger 34 spaced apart from the actuator valve 18, as shown in FIG7(a).

[0158] The first plunger 34, for example, is used to dispense medication (not shown) from the first syringe 58 in the distal axial direction A D The movement causes the first plunger 34 to abut against the abutment forming portion 32 of the actuator valve 18, as shown, for example, in FIG7(b).

[0159] Subsequently, the first plunger 34 moves in the distal axial direction A D Further movement of the actuator valve 18 relative to the needle assembly body 12 will cause the actuator valve 18 to move toward its first open position.

[0160] This initial movement of actuator valve 18 toward its first open position also causes actuator valve 18 to move relative to conduit member 40 and to slide on conduit member 40, which pushes first drive member 48 in the proximal axial direction A. P The needle 14 passes through the actuator valve 18, and more specifically through the soft outer sheath 28 of the actuator valve 18, so that the proximal needle portion 52 is exposed beyond the actuator valve 18. Furthermore, when the proximal needle portion 52 is exposed beyond the actuator valve 18, it is similarly driven to engage with the second drive member 54, thereby firmly securing the needle 14 and the second drive member 54 to each other.

[0161] Subsequently, the first plunger 34 moves in the distal axial direction A D Further movement of the actuator valve 18 moves it to its first open position, as shown in Figure 7(c).

[0162] This movement of actuator valve 18 to its open position fluidly connects the modified propellant storage volume 122 to the second vent duct 82, causing propellant (highlighted in FIG7(c)) to be released from the modified propellant storage volume 22 and guided in the distal axial direction A. D It flows through the second ventilation duct 82 and into the foldable chamber 84.

[0163] Propellant (highlighted) is released from propellant storage volume 22 into foldable chamber 84 such that chamber 84 is positioned above needle 14 in the distal axial direction A. D The expansion allows the foldable chamber 84 to provide the required first degree of coverage, i.e., shielding, to the needle 14.

[0164] The actuator valve 18 continues to move further to its second open position, additionally fluidly communicating the modified propellant storage volume 122 with the first vent duct 36, i.e., via the connecting conduit 68 in the actuator valve 18 and the inlet orifice 46 in the first vent duct 36.

[0165] Therefore, another propellant now released from the modified propellant storage volume 122 (highlighted in Figure 7(d)) ​​is guided along the first vent duct 36 toward its proximal end 38 in the proximal axial direction A. P The fluid flows upward and contacts the first drive member 48. At the same time, the actuator valve 18 continues to move further to its second open position, similarly separating the second drive member 54 from the first modified plunger 34, i.e., by forcing the deformable chamfered hooks 64, 66 to overlap each other.

[0166] Therefore, as shown in Figure 7(d), the released propellant (highlighted) now acts on the foldable chamber 84 and the first drive member 48 after a delay.

[0167] Similar to other similar embodiments of the invention, the propellant released acting on the first drive member 48 is in the proximal axial direction A. P The first drive member 48 is pushed upward (i.e. moved), thereby causing the needle 14, which is securely fixed to the first drive member 148, to move in the same proximal axial direction A. P Initial motion.

[0168] Furthermore, once the first drive member 48 and the needle 14 are in the proximal axial direction A P After this initial motion, and with the propellant having escaped through the first drive member 48 and passed the proximal end 38 of the first vent duct 36, the propellant will then act additionally on the second drive member 54 to continue the needle 14 in the proximal axial direction A. PThe movement of the needle 14 within the needle assembly 120 and the associated syringe body 56 (as shown in FIG7(e)) completes a second desired degree of retraction (not shown).

[0169] Therefore, the first degree of shielding of the needle 14 caused by the release of the propellant expanding the foldable chamber 84, and the second degree of retraction of the needle 14 caused by the release of the propellant acting on the first drive member 48 and then on the second drive member 54, similarly make the fifth needle assembly 120 have a fully enclosed needle 14, i.e., fully shielded (not shown).

[0170] As shown in Figures 8(a) and 8(b), the needle assembly according to the sixth embodiment of the present invention is generally indicated by reference numeral 130.

[0171] The sixth pin assembly 130 has many similarities to the first pin assembly 10 and the fourth pin assembly 110. Although not all of these similar features are shown, these features share the same reference numerals.

[0172] Specifically, the sixth needle assembly 130 shares the first ventilation conduit 36 ​​with each of the first needle assembly 10 and the fourth needle assembly 110, and is therefore operable to allow ventilation in the distal axial direction A as needed. D and proximal axial direction A P The propellant stream is guided in one or both directions.

[0173] As shown in the figure, this first ventilation conduit 36 ​​is defined by a hollow conduit member 40, which is securely fixed at its distal end 42 to the needle assembly body 12, in which the needle (not shown) can move axially, for example, at least in the proximal axial direction A. P The hollow conduit member 40 also has a first opening 44 formed therein to define an inlet orifice 46 leading to the first ventilation conduit 36.

[0174] However, other types and constructions of the first ventilation duct are also possible.

[0175] However, including the first ventilation tube 36 does indeed mean that the sixth needle assembly 130 can operate in the same manner as either of the following:

[0176] - First needle assembly 10, i.e., guiding the released propellant flow along the distal axial direction A D Acting on the first drive member (not shown) to retract the relevant pin (not shown); or

[0177] - The fourth needle assembly 110, i.e., simultaneously along the proximal axial direction A D and distal axial direction A PThe propellant flow is guided to act on a first drive member (not shown) to retract the associated needle (not shown) and on a foldable chamber (also not shown) to expand the chamber on the needle.

[0178] However, the sixth needle assembly 130 differs from the first needle assembly 10 and the fourth needle assembly 110 because it includes a second actuator valve 132, which is different from the first actuator valve 18 included in the first needle assembly 10 and the fourth needle assembly 110, respectively.

[0179] More specifically, the second actuator valve 132 itself defines a propellant storage volume 22, and more specifically, it also includes an external support formation 134 having a hollow interior 136 defining the propellant storage volume 22.

[0180] like Figure 9 As shown, the outer support forming portion 134 is formed of an elongated hollow central body 138, preferably having a circular cross-section (but other cross-sectional profiles are also possible), and a first end cap 140 and a second end cap 142 are fixed to the central body 138. Preferably, the second end cap 142 is integrally formed with the central body 138, and the first end cap 140 is bonded to the central body 138 using a UV-curable adhesive 148, but other fixing methods are also possible.

[0181] In other embodiments of the invention (not shown), the first end cap and the second end cap may be modified to extend toward each other and be fixed to each other, thereby eliminating the need for a central body.

[0182] In any case, the first end cap 140 is combined with the third sealing forming portion 144, and the second end cap 142 is combined with the fourth sealing forming portion 146. Both of these sealing forming portions are sealed to the first vent duct 36, that is, sealed to the duct member 36 that defines the first vent duct 40, in order to maintain the sealing integrity of the propellant storage volume 22.

[0183] The external support forming portion 134 and the first end cap 140 and the second end cap 142 of the second actuator valve 132 are thus combined to form a generally annular propellant storage volume 22, but other shapes of the propellant storage volume are also possible.

[0184] Preferably, each of the third sealing forming portion 140 and the fourth sealing forming portion 142 is formed of (or includes elements formed thereof, such as O-rings or skins) a relatively soft, elastically deformable material (e.g., a natural or synthetic elastomer), while the outer support forming portion 134, such as the central body 138 and each end cap 140, 142, is formed of or includes a harder, less deformable material. For example, one or both of the third sealing forming portion 140 and the fourth sealing forming portion 142 may be overmolded onto the corresponding end cap 140, 142 with a thermoplastic elastomer, i.e., creating an additional layer of thermoplastic rubber material.

[0185] Furthermore, the third sealing forming portion 144 and the fourth sealing forming portion 146 are movable relative to the first venting conduit 36, and more specifically, are slidable (while maintaining seal integrity), so that the second actuator valve 132 is movable within the needle assembly body 12, and more specifically, within the hollow, generally annular interior 20 of the needle assembly body 12. However, it is not necessary for this to be the case; other shapes of interiors and only partially hollow interiors are also possible.

[0186] In this manner, the second actuator valve 132 can move between a closed position (as shown in FIG8(a)) and an open position (as shown in FIG8(b)). In the closed position, the propellant (not shown) is held under pressure in the propellant storage volume 22. In the open position, the propellant is released from the propellant storage volume 22 so that the corresponding needle is shielded, i.e. enclosed or sealed (not shown).

[0187] To facilitate this movement of the second actuator valve 132, a second abutment forming portion 32 is similarly defined, which, in use, allows the syringe plunger to abut against in order to move the second actuator valve 132 from its closed position to its open position.

[0188] Before the sixth needle assembly 130 is used, for example before the drug is injected into the receptor using the associated injection device (not shown), the second actuator valve 132 is in its closed position, as shown in FIG8(a), and the propellant (not shown) is held under pressure in the propellant storage volume 22.

[0189] During drug dispensing from the associated injection device, the plunger of the device abuts against the abutment formation 32 of the second actuator valve 132, such that the plunger is positioned in the distal axial direction A. D The continued further movement on the upper part additionally begins to move the second actuator valve 132 relative to the needle assembly body 12 and toward its open position.

[0190] This initial movement of the second actuator valve 132 toward its open position causes the second actuator valve 132 to move relative to the conduit member 40, and more specifically, causes the second actuator valve 132 to slide on the conduit member 40.

[0191] Subsequently, the plunger moves in the distal axial direction A D Further movement of the upper part moves the second actuator valve 132 to its open position, as shown in FIG8(b). This puts the propellant storage volume 22 into fluid communication with the first vent duct 36, i.e., via an inlet orifice 46 formed in the duct member 40, so that propellant (not shown) is released from the propellant storage volume 22 and guided into the first vent duct 36, optionally along the proximal axial direction A. P and distal axial direction A D The flow may occur in one or both directions, for example, acting on the first drive member to retract the relevant needle; and / or acting on the foldable chamber to expand the chamber on the needle.

Claims

1. A needle assembly for engagement with a syringe having an elongated hollow syringe body, wherein a plunger is slidably received within the syringe body, the needle assembly comprising: A needle assembly body having a hypodermic needle connected to the needle assembly body and extending from the distal end of the needle assembly body; as well as An actuator valve, which is movably received within the needle assembly body and configured to define a propellant storage volume, The actuator valve is movable between a closed position and an open position, in which the propellant is held under pressure in the propellant storage volume, and in the open position, the propellant is released from the propellant storage volume to shield the needle.

2. The needle assembly according to claim 1, characterized in that, The actuator valve itself defines the propellant storage volume.

3. The needle assembly according to claim 2, characterized in that, The actuator valve includes an external support forming portion having a hollow interior that defines the propellant storage volume.

4. The needle assembly according to claim 1, characterized in that, The actuator valve cooperates with the needle assembly body to define the propellant storage volume therebetween.

5. The needle assembly according to claim 4, characterized in that, The actuator valve includes a first and a second seal portion that are axially spaced apart, with the propellant storage volume formed between the seal portions.

6. The needle assembly according to any of the preceding claims, characterized in that, The propellant storage volume has an annular shape.

7. The needle assembly according to any one of the preceding claims, characterized in that, The actuator valve defines an abutment formation, which the syringe plunger can abut against during use to move the actuator valve from its closed position to its open position.

8. The needle assembly according to any one of the preceding claims, characterized in that, The movement of the actuator valve into the open position causes the propellant storage volume to be in fluid communication with the venting duct, which is configured to guide the released propellant flow in one or both of the distal and proximal axial directions.

9. The needle assembly according to claim 8, characterized in that, The actuator valve moves to the open position to fluidly communicate the propellant storage volume with the first vent duct, which extends in the proximal axial direction and is configured to guide the released propellant flow in the proximal axial direction.

10. The needle assembly according to claim 8, characterized in that, The actuator valve moves to the open position to fluidly communicate the propellant storage volume with the second vent duct, which extends in the distal axial direction and is configured to guide the released propellant flow in the distal axial direction.

11. The needle assembly according to claim 10, characterized in that, The second ventilation conduit extends through the needle assembly body.

12. The needle assembly according to any one of claims 9, 10, and 11, characterized in that, The second venting duct is further configured to be in fluid communication with the first venting duct, such that when the actuator valve is moved to the open position, the propellant storage volume is arranged to be in fluid communication with the first venting duct via the second venting duct.

13. The needle assembly according to claim 9, characterized in that, The first ventilation duct also extends in a distal axial direction, thereby being configured to guide the released propellant flow in both the proximal and distal axial directions when the actuator valve is moved to its open position.

14. The needle assembly according to any one of claims 9, 10, and 11, characterized in that, When the actuator valve is moved to the first open position, the propellant storage volume is arranged in fluid communication with one of the first and second venting conduits, and when the actuator valve is moved to the second open position, the propellant storage volume is arranged in fluid communication with both the first and second venting conduits.

15. The needle assembly according to claim 9 or any one of the claims dependent on claim 9, characterized in that, The first venting conduit extends between the actuator valve and the needle and terminates at the proximal end, and is securely fixed to the first drive member of the needle, sealing against the proximal end. Thereby, propellant released into the first venting conduit and guided to flow in the axial direction of the proximal end acts on the first drive member to move the first drive member and the needle securely fixed to the first drive member in the axial direction of the proximal end.

16. The needle assembly according to claim 15, characterized in that, The first ventilation conduit is defined by a hollow conduit component, which is securely fixed at its distal end to the needle assembly body, and the needle is axially movable within the hollow conduit component.

17. The needle assembly according to claim 14, characterized in that, The hollow conduit member has a first opening formed therein to define the inlet orifice of the first ventilation conduit.

18. The needle assembly according to claim 16 or 17, characterized in that, The actuator valve is slidable on the catheter member, and the first drive member is spaced apart on the proximal side of the needle to define a proximal needle portion, whereby movement of the actuator valve toward the open position also exposes the proximal needle portion beyond the actuator valve.

19. The needle assembly according to claim 18, characterized in that, The proximal needle portion engages with a second drive member configured to enclose a hollow syringe body that is connected to the syringe assembly during use. Thus, after the initial movement of the first drive member and the needle in the proximal axial direction, the propellant guided to flow through the first conduit in the proximal direction also acts on the second drive member to allow the movement of the needle in the proximal axial direction to continue.

20. The needle assembly according to claim 19, characterized in that, The needle assembly engages with a syringe having a modified plunger configured to carry the second drive member and securely fasten the second drive member to the proximal needle portion before abutting against the abutment formation of the actuator valve.

21. The needle assembly according to claim 20, characterized in that, The second drive member and the modified plunger include mutually cooperating forming portions to selectively fix the second drive member and the modified plunger to each other.

22. The needle assembly according to claim 21, characterized in that, At least one of the mutually cooperating forming parts is elastically deformable.

23. The needle assembly according to claim 10 or any of the claims dependent on claim 10, characterized in that, The released propellant, guided to flow along the distal axial direction, is further guided into a foldable chamber that is sealed and fixed to the needle assembly body, thereby releasing the propellant from the propellant storage volume into the foldable chamber, causing the chamber to expand along the distal axial direction.

24. The needle assembly according to claim 23, characterized in that, The foldable chamber is sealed between the needle assembly body and the protective assembly, thereby releasing propellant from the propellant storage volume into the foldable chamber through the second venting conduit, causing the chamber to expand in the distal axial direction, and also pushing the protective assembly across the needle in the distal axial direction.

25. A method of using a needle assembly according to any one of the preceding claims, characterized in that, The step includes moving the actuator valve between a closed position and an open position, wherein in the closed position the propellant is held under pressure in the propellant storage volume, and in the open position the propellant is released from the propellant storage volume to shield the needle.

26. An injection device comprising the needle assembly according to claim 1.

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