Injection needle having shield activated valve

Abstract

The present invention relates to a needle assembly having a build-in valve (30). The needle assembly is built up from a hub (20) carrying a needle cannula (10) and a telescopically movable shield (40) which axially covers the distal tip (13) of the needle cannula (10) between injections. The valve (30) is operated by the shield (40) and is arranged such that it is closed when the distal tip (13) of the needle cannula (10) is covered by the shield (40) and is opened when the telescopically movable shield (40) has been retracted a specific distance (X) proximally to the distal tip (13) of the distal cannula part (11).

Claims

1. A needle assembly having a built-in valve, comprising: a hub comprising structure for connecting the hub to an injection device, a proximal cannula part for penetrating into a reservoir containing a liquid drug, a distal cannula part having a distal tip for penetrating the skin of an object, a telescopically movable shield which is movable relative to the hub between: a first position wherein the shield axially covers the distal tip of the distal cannula part, and a second position wherein the shield is axially retracted proximally towards the proximal cannula part, a valve positioned between the proximal cannula part and the distal cannula part and which valve is closed when the telescopically movable shield is in the first position and open when the telescopically movable shield is in the second position such that the valve is opened when the telescopically movable shield has been retracted a specific distance (X) proximally to the distal tip of the distal cannula part, and wherein the needle assembly is multiple usable such that the same distal needle cannula part is used for several injections and the telescopically movable shield carries a reservoir containing an antiseptic liquid in which the distal tip of the distal cannula part is maintained and cleaned between injections.

2. A needle assembly according to claim 1, wherein the distal cannula part and the proximal cannula part are separate cannulae.

3. A needle assembly according to claim 2, wherein the distal part and the proximal part are connected by a flexible tube.

4. A needle assembly according to claim 3, wherein the distal part, the proximal part and the flexible tube are carried by the hub.

5. A needle assembly according to claim 3, wherein the valve compresses the flexible tube when the telescopically movable shield is in the first position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be explained more fully below in connection with a preferred embodiment and with reference to the drawings in which:

(2) FIG. 1 shows a cross-sectional view of the shielded injection needle.

(3) FIG. 2 shows a view of the valve arrangement in the closed position.

(4) FIG. 3 shows a view of the valve arrangement in the open position.

(5) FIG. 4A-B shows a view of a further embodiment of the shielded needle cannula.

(6) FIG. 5A-B Shows a view of an embodiment having a uniform needle cannula.

(7) The figures are schematic and simplified for clarity, and they just show details, which are essential to the understanding of the invention, while other details are left out. Throughout, the same reference numerals are used for identical or corresponding parts.

DETAILED DESCRIPTION OF EMBODIMENT

(8) When in the following terms as upper and lower, right and left, horizontal and vertical, clockwise and counter clockwise or similar relative expressions are used, these only refer to the appended figures and not to an actual situation of use. The shown figures are schematic representations for which reason the configuration of the different structures as well as there relative dimensions are intended to serve illustrative purposes only.

(9) In that context it may be convenient to define that the term distal end in the appended figures is meant to refer to the end of the needle cannula penetrating the skin of the user during injection whereas the term proximal end is meant to refer to the opposite end pointing away from the user and used to penetrate the cartridge in the injection device to which the needle assembly is attached.

(10) In the different embodiments disclosed, the same elements are identified by the same reference numbers. The major elements being; A needle cannula 10, a hub 20, a valve 30, a movable shield 40, and an insert 50.

(11) FIG. 1 discloses an embodiment having a build in valve arrangement 30 which is disclosed in further details in FIGS. 2 and 3.

(12) The needle cannula 10 has a distal part 11 and a proximal part 12 both secured to the hub 20 and connected to each other through a flexible tube 31 which flexible tube 31 constitutes a part of the valve arrangement 30 as shown in FIG. 2-3.

(13) The valve arrangement 30 comprises a number of squeeze arms 32 which are able to squeeze the flexible tube 31 such that the liquid drug cannot flow through the lumen of the flexible tube 31. These squeeze arms 32 are provided on suspended bridge parts 33 which are also secured to the hub 20.

(14) When the bridge part 33 is in a situation of rest as disclosed in FIG. 2, the squeeze arms 32 squeezes the flexible tube 31 such that the valve arrangement 30 in this position is closed. All though the figures only disclose two such bridge arms 33 any number can be provided for.

(15) The radial movement of these squeeze arms 32 are controlled by the axial movement of the shield 40. The shield 40 is urged in the distal direction by a first compression spring 21 which is located between the hub 20 and the shield 40. The spring 21 can be made as a separate metallic spring or it can alternatively be formed as a plastic spring moulded integral with e.g. the hub 20. The shield 40 is further provided with a plurality of axially extending arms 41. When the shield 40 is moved proximally during injection as disclosed in FIG. 3 these axially extending arms 41 activates the bridge part 33 via an actuation member 34 whereby the bridge part 33 flex away from is axial rest position. The squeeze arms 32 moves together with the bridge part 33 to a position in which the squeeze arms 32 does not compress the flexible tube 31 thus allowing the liquid drug to flow freely through the flexible tube 31.

(16) As best seen in FIG. 3, the valve arrangement 30 opens once the shield 40 has been moved a predetermined distance (X) in the proximal direction and the axially extending arms 41 of the shield 40 moves the squeeze arms 32 radially. The result being that the valve arrangement 30 is opened and respectively closed only when the distal tip 13 of the needle cannula 10 is the same predetermined distance (X) inside the body of the user as the distal surface 42 of the shield 40 abuts the body of the user during injection.

(17) When the distal tip 13 of the distal part 11 is removed from the object, the spring 21 urges the movable shield 40 into its first position in which it covers the distal tip 13. During retraction of the needle cannula 10 from the body of the user, the valve arrangement 30 shuts off the liquid flow through the lumen of the needle cannula 10 when the distal surface 42 of the shield 40 has passed the predetermined distance (X) from the tip 13 of the needle cannula 10 moving towards the distal tip 13.

(18) A different embodiment is disclosed in FIG. 4A-B.

(19) The needle cannula 10 is also here separated into two parts, a distal part 11 and a proximal part 12. The proximal part 12 is secured to the hub 20 and penetrates into the cartridge 25 when the needle assembly is attached to an injection device.

(20) In this embodiment, the hub 20 further carries the insert 50 which insert 50 has one single chamber 55 into which the liquid drug flows whenever the proximal part 12 is located in liquid communication with the interior of the cartridge 25.

(21) A needle shield 40 slides telescopically on the hub 20 and is urged in the distal direction by a spring 21. The distal part 11 is secured to a needle plate 23 which is urged in the distal direction by a second compression spring 24 provided between the needle plate 23 and the hub 20.

(22) The first position of the needle shield 40 is depictured in FIG. 4A. In this situation of rest, the first spring 21 urges the shield 40 in the distal direction such that the shield 40 covers the distal end 13 of the distal part 11 and the second spring 24 urges the distal part 11 in the distal direction such that the proximal end 19 of the distal part 11 is located distally to the single chamber 55 and concealed within the insert 50. In this situation the valve arrangement 30 is shut.

(23) In the second position wherein the user performs an injection, the distal surface 42 of the shield 40 is pressed in the proximal direction by the impact with the skin of the user. Once the first spring 21 is compressed, the needle plate 23 and with it the distal part 11 is moved in the proximal direction against the bias of the second spring 24. During this proximally movement of the distal part 11 the proximal end 19 of the distal part 11 is moved into the single chamber 55 thereby creating a liquid flow from the interior of cartridge 25 and into the skin of the user. The valve arrangement 30 is thus open.

(24) FIG. 5A-B discloses a different embodiment in which the distal part 11 and the proximal part 12 are uniform such that they form part of one and the same needle cannula 10. The needle cannula 10 is secured to the hub 20.

(25) The needle cannula 10 is provided with two radial openings 14, 15; a proximal opening 14 and a distal opening 15. The lumen of the needle cannula 10 is blocked by an insert 16 which divides the lumen into a proximal lumen 17 and a distal lumen 18. The proximal lumen 17 is, in operation, in contact with the liquid drug inside the cartridge 25, however the insert 16 prevents the liquid drug to flow from the proximal lumen 17 and into the distal lumen 18. The distal opening 14 forms a liquid communication with the distal lumen 17 and the proximal opening 15 form a liquid communication with the distal lumen 18.

(26) The shield 40 which is urged in the distal direction by the spring 21 encompassed between the shield 40 and a ridge 22 provided on the hub 20, carries an insert 50. The insert 50 is preferably made from a rubber material in order to obtain an adequate liquid seal against the needle cannula 10.

(27) The insert 50 can be formed integral with the shield 40 or alternatively it can be a separate insert 50, which, as disclosed in FIG. 5A-B, are connected to a plate 43 which is then attached to the shield 40.

(28) The insert 50 is provided with a distal chamber 51 and a proximal chamber 52. These two chambers 51, 52 are separated by a flange 53 which slides on the needle cannula 10 in a liquid tight seal.

(29) In one embodiment the distal chamber 51 contains an antiseptic liquid suitable for keeping the distal tip 13 of the needle cannula 10 sterile or at least clean.

(30) The proximal chamber 52 is empty and is in the non-use situation (disclosed in FIG. 5A) located in a position distal to the distal opening 15 in the needle cannula 10. In this situation, the tip 13 of the needle cannula 10 is located inside the distal chamber 51. Further, the proximal chamber 52 has a length sufficient for it to axially connect the distal opening 14 and the proximal opening 14 in order to form a liquid flow-way between the two openings 14, 15.

(31) During injection, as disclosed in FIG. 5B, the shield 40 together with the insert 50 is slided in the proximal direction against the bias of the spring 21 such that the distal tip 13 of the needle cannula 10 penetrates through a distal end 54 of the insert 50. In this position, the proximal chamber 52 forms a liquid flow-way connecting the proximal opening 14 and the distal opening 15 thereby allowing the liquid drug to flow from the proximal lumen 17 and into the distal lumen 18, and ultimately to flow into the user.

(32) Some preferred embodiments have been shown in the foregoing, but it should be stressed that the invention is not limited to these, but may be embodied in other ways within the subject matter defined in the following claims.