AU2006200679B2

AU2006200679B2 - Spring clip as needle tip protection for a safety IV catheter

Info

Publication number: AU2006200679B2
Application number: AU2006200679A
Authority: AU
Inventors: Kevin Woehr
Original assignee: B Braun Melsungen AG
Current assignee: B Braun Melsungen AG
Priority date: 1997-08-20
Filing date: 2006-02-17
Publication date: 2008-11-20
Anticipated expiration: 2018-08-18
Also published as: AU783650B2; AU783650C; AU4207001A; AU2006200679A1

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT

(ORIGINAL)

Name of Applicant(s): B. Braun Melsungen AG, Carl-Braun-Strasse 1, 34212 Melsungen, Germany Actual Inventor(s): Address for Service: Invention Title: Kevin WOEHR DAVIES COLLISON CAVE, Patent Trademark Attorneys, of 1 Nicholson Street, Melbourne, 3000, Victoria, Australia Ph: 03 9254 2777 Fax: 03 9254 2770 Attorney Code: DM Spring clip as needle tip protection for a safety IV catheter The following statement is a full description of this invention, including the best method of performing it known to us:- 1 P:%OPER\LKA\12724490 Ispadoc. 13ATE IOERGEFORIOAT 00

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0 SPRING CLIP AS NEEDLE TIP PROTECTION FOR A SAFETY IV CATHETER The invention relates to an intravenous catheter.

o An intravenous catheter (IV catheter) is known from US-A-5 135 504 (McLees) wherein the needle guard is a hollow cylinder with a split end and slanted- Soverlapping end caps. The needle tip at the distal end of the needle is flared out c' and is slightly larger in diameter than the needle shaft and the inside diameter of the needle guard. A retaining ring is held tightly by a friction fit with the catheter hub wherein the outside diameter of the needle guard is less than the inside diameter of this retaining ring so that normally the needle guard can easily slide through the ring. When the needle is withdrawn and the flared out needle tip goes inside the needle guard, the needle guard end caps are free to close and the needle tip shoulder pulls the needle guard through the retaining ring thus forcing the flared end of the needle guard closed.

The McLees protective device requires an irksome, extra pulling action or tug on the needle guard through a retention ring to remove the protected needle from the catheter hub. The McLees device also requires the assembly of two separate components and is thus relatively costly to manufacture. In addition, the needle in the McLees device includes a larger diameter portion near and at the needle tip. This feature of the McLees device would require that the remainder of the needle be of a lesser diameter which would have the adverse effect of slowing the blood flashback through the needle.

Additionally this flared out needle tip is impractical for a number of reasons. The device can not be assembled in the usual manner by inserting the needle tip first through the catheter, without damaging the catheter. Further, when the user wants to withdraw the needle, the flared out needle tip must expand the catheter material to allow it to pass.

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o I.V. catheters are primarily used to administer fluids, sometimes containing O medications, directly into a patient's vascular system. The catheter is inserted into a patient's vein by a health care worker by using a handheld placement device that includes a sharp tip needle. The needle is positioned in the interior hollow portion of the catheter with its tip extended slightly beyond the edge of the catheter. The end of the apparatus opposite the needle tip is made up of the O needle connected to a needle hub which is capable of being held by the health care worker during the insertion procedure.

The insertion procedure contains four basic steps: the health care worker inserts the needle and catheter together into the patient's vein; after insertion into the vein with the needle point, the catheter is forwarded into the vein of the patient by the health care worker pushing the catheter with his or her finger; the health care worker withdraws the needle by grasping the hub end (opposite the point end) while at the same time applying pressure to the patient's skin at the insertion site with his or her free hand; and the health care worker then tapes the now inserted catheter to the patient's skin and connects the exposed end of the catheter, the catheter hub, to the source of the fluid to be administered into the patient's vein.

The problem is that immediately after the withdrawal of the needle from the patient's vein, the health care worker who is, at this time, involved in at least two urgent procedures must place the exposed needle tip at a nearby location and address the tasks required to accomplish the needle withdrawal. It is at this juncture that the exposed needle tip creates a danger of an accidental needle stick occurring, which under the circumstances, leaves the health care worker vulnerable to the transmission of various, dangerous blood-borne pathogens, including AIDS and hepatitis.

This danger to the health care worker from accidental needle sticks has caused an impetus for the development of a safer IV catheter in which the occurrence of such accidental needle sticks is prevented. Safety catheters that have been P:OPER\LKAMI2724490 Isp do- 13ATE IOERCEORIOAT 00 -3o developed to achieve this result are disclosed, for example, In Lemieux Reissue NO Patent No. Re. 34,416, Crawford U.S. Patent No. 5,558,651 Gaba U.S. Patent No. 5,697,907, and Dombrowski U.S. Patent No. 4,978,344. Kulli U.S. Patent No.

4,929,241and Chamuel U.S. Patent No. 5,053,017 disclose a protective needle 5 guard for use with a hypodermic needle.

c The prior art safety catheters all exhibit one or more drawbacks that have thus far Slimited their usefulness and full acceptance by health-care workers. For example, Sin the safety catheter disclosed in the Lemieux patent, the force required to engage the needle slot within the guard flange is relatively great and would interfere with the removal of the needle. Reducing this force to a more acceptable level would create the possibility of the needle guard remaining in the catheter hub after the needle is removed from the catheter. As a result, the safety catheter disclosed in the Lemieux patent would not consistently function in a reliable manner.

Similarly, the user of the safety catheter disclosed in the Dombrowski patent would have to exert a considerable force to remove the protective cap from the catheter hub, when the cap engages a needle. The safety catheter disclosed in the Dombrowski patent would also be relatively expensive to fabricate because of its inclusion of a flexible flange and a tether.

It is an object of this invention to provide an intravenous catheter which will overcome or at least ameliorate one or more of the above disadvantages.

Accordingly, in one aspect this invention provides an intravenous catheter comprising a catheter hub attached to the proximal end of a tubular catheter and having a chamber, a needle having a needle shaft and a needle tip, wherein the needle is provided with an increased diameter, and a needle guard retained in a ready position wholly in the chamber of the catheter hub, wherein the needle guard has two resilient arms which are urged away from each other by said needle shaft in the ready position, each arm being provided at the distal end with a distal guard wall positioned on the shaft of the needle in the ready position and wherein PAOPERLKA2724490 Isp.doc 13ATE IOERCEFORIOAT 00 -4c, o the distal guard walls overlap each other in front of the needle tip when the needle _guard is in a blocking position, wherein the needle shaft has a segment slightly proximal to the needle tip, the segment being provided with an increased diameter C in relation to the needle tip, and the needle guard having a rear wall from which the O 5 arms extend in a distal direction wherein the rear wall includes an opening through which the needle shaft passes, wherein the diameter of the increased diameter IDsegment is greater than that of said opening, and wherein an inner wall of the Schamber of the catheter hub is provided with a retaining means in the form of an annular groove by which the needle guard is retained in the catheter hub in the ready position.

At least embodiments of the invention provide an intravenous catheter, which reliably and automatically prevents accidental, inadvertent contact with the needle tip after use.

At least embodiments of the invention further provide an intravenous catheter which provides reliable protection to the health care practitioner against needle sticks without requiring any change in the manner of use of the safety catheter by the practitioner.

At least embodiments of the invention further provide an intravenous catheter of the type described which is relatively simple and inexpensive to manufacture.

At least embodiments of the invention further provide a safety catheter of the type described in which removal of the needle from the needle guard after use is prevented.

The safety IV catheter of the invention preferably includes a resilient spring clip needle guard. The spring clip is inserted into the catheter hub and is urged by the needle shaft into contact with the inner walls of the catheter hub so that the needle guard is reliably retained therein. When the needle is withdrawn from the catheter, the force it had previously exerted on the needle guard is released. At this time, the distal end wall of the needle guard blocks the distal pointed end tip P:kOPERkLKAI272449O Ispadow- OATE IOERGEFORLOAT 00 o of the needle. In addition, the spring clip and protected needle can be readily IDand safely removed from the catheter hub. The needle may be provided with a bulge which cooperates with the needle guard to prevent the inadvertent removal of the needle from the needle guard after their removal from the catheter hub.

In the embodiment of the spring clip safety catheter of the invention, a retaining N groove or bump is formed in the inner wall of the catheter hub, which, in the Sready position, engages arm of the spring clip to add in the retention of the spring Sclip in the catheter hub.

In the embodiment of the invention the spring clip needle guard is in the form of resilient intersecting arms, each terminating at a distal guard wall. When the needle is in the ready position it passes through the guard and urges the resilient arms away from each other and against, the inner wall of the catheter hub. When the needle is retracted past the guard walls, the resilient arms spring to the safety position in which both of the guard walls are positioned distally from the needle tip, thereby to form a barrier that prevents inadvertent contact with the needle tip.

An embodiment of the present invention will now be described, by way of example only, with respect the accompanying drawings, in which: Figs. 1A and 1B are views in partial cross-section of a safety IV catheter in accordance with an embodiment of the invention shown in the ready and protected positions, respectively; and Fig. 2 is a perspective of the needle guard clip of the embodiment of Fig. B.

The safety IV catheter of the invention, generally designated 10, includes a needle hub 12 that includes an axial opening which securely receives the proximal end of a needle 16 having a sharpened tip 18. The needle hub 12, as is conventional, is hollow and includes a flash chamber. As is also conventional, the needle 16 is received within a hollow tubular catheter 24, the proximal end of which is concentrically affixed within the distal end of a catheter hub 26 having a distal section and a contiguous, larger diameter proximal section.

P:\OPER.KA2724490 Ispdoc- 13ATE I IOERGEFORIOAT 00 -6o The catheter hub 26 terminates at its proximal end in a luer fitting adapted to IDreceive a tubing set, which in a known manner, administers intravenous fluid into the patient. The catheter 24 is secured within an axial passageway in distal hub section by means of a sleeve received within passageway, which engages the C 5 proximal end of the catheter.

c In the ready position of the catheter shown in Fig. 1A, the distal end of the needle hub 12 is snugly received in the proximal end of the interior of a chamber such c that the needle 16 extends through the chamber, the passageway and distally beyond the catheter hub 26 and catheter 24 so that its tip extends beyond the tapered distal end of the catheter and the increased diameter segment in form of a bulge 138 of the needle is positioned within the catheter 24.

In use, the distal tip of the needle and the catheter are inserted into a patient's vein. Thereafter, the health care practitioner manually places the catheter further into the vein and then withdraws the needle by grasping and moving by hand the proximal end of the needle hub 12. The luer of the catheter hub 26 is then fitted with a source of the fluid that is to be administered into the patient's vein.

In accordance with the present invention, as the needle 16 is being withdrawn from the patient, a protective needle guard 120 located within hub chamber automatically snaps into a retracted position in which it blocks access to the distal needle tip and prevents further distal movement of the needle tip, thereby to prevent accidental contact by the health care practitioner with the needle tip.

As shown in Figs. 1A and 1B, the needle guard 120, is in the form of a unitary spring clip that is preferably made of a resilient metal such as stainless steel.

The embodiment of the spring clip needle guard 120 disclosed in Figs. 1A, 1B, and 2 comprises first and second arms 122 and 124 respectively joined at their proximal ends in a hinged arrangement at 125 to the ends of a rear wall 126. The distal ends of arms 122, 124 each include a curved protrusion 128 extending to a distal end or guard wall 130, which in turn terminates in a lip 132. As seen best in P:OPERLKA%1272449C Ispd- 13ATE IOERGEFORIOAT 00 -7-

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o Fig. 2, rear wall 126 includes a central opening 134, and arms 122 and 124 each IDinclude a narrow portion 142 that extends between a distal wide portion 140 and a proximal wide portion 144. A lateral clamping edge 146 is defined at the distal- C wide portion 144.

NO

As shown in Fig. 1A, when the needle guard 120 is in its ready position, the Ccurved protrusions 128 in each of arms 122, 124 are received in an annular groove or ring 136 formed in the inner wall of catheter hub 26, which is removably Sfit into the distal end of a needle hub 12. The needle 16 having a sharpened tip 18 at its distal end is received within a tubular catheter 24, which is secured to the distal end of catheter hub 26. The proximal end of needle 16 passes through opening 134 in rear wall 126. Needle 16 includes an increased diameter bulge 138, which is sufficiently small to allow needle 16 to move axially along catheter 24, but greater in diameter than opening 134 for reasons to be described below.

In the ready position illustrated in Fig. 1A, the needle shaft passes through the needle guard and applies an outward radial force on resilient arms 122, 124 by means of its engagement with lips 132, so as to urge the curved protrusions 128 of each of the arms into the annular groove 136, so as to retain needle guard 120 in a fixed position within the inner wall of catheter hub 26. The shaft of needle 16 that passes through the needle guard 120 frictionally engages the inner edges of the narrow portions 142 of arms 122, 124 so as to further retain the needle in its ready position.

When the needle is retracted axially, to the right as viewed in Fig. 1A, within the catheter hub, and moves past the end lip 132 of the needle guard, the radial force previously exerted on arms 122, 124 of needle guard 120 is suddenly released.

This causes the distal end walls 130 of the needle guard to be released from their seat in the annular groove 136 and to pivot inwards into the catheter hub until, as seen in Fig. 1B, the end walls 130 overlap one another at a location distally in front of the needle tip, thereby to form a barrier that prevents inadvertent contact r PIOPERLKA%'12724490 Ipado- HATE IOERGEFOR OAT 00 -8with, and distal movement of, the needle tip. At the same time, the clamping edges 146 of the needle guard are urged against the needle tip to restrict further axial movement of the needle.

NO As also shown in Fig. 1B, the needle guard 120 and the needle clamped to the 0 needle guard after needle retraction can be removed from the catheter hub as a Iunitary assembly, and safely discarded. If an attempt is made, intentionally or Sinadvertently, to pull the needle further to the right, as viewed in Fig. 1B, out of the needle guard, the bulge 138 on the needle shaft will come into contact with the end wall 126, and since its diameter is greater than that of opening 134, the end wall 126 will at this point prevent any further axial movement of the needle out of the needle guard.

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

Claims

1. An intravenous catheter comprising a catheter hub attached to the proximal end of a tubular catheter and having a chamber, a needle having a needle shaft and a needle tip, wherein the needle is Sprovided with an increased diameter, and \D Sa needle guard retained in a ready position wholly in the chamber of the catheter Shub, wherein the needle guard has two resilient arms which are urged away from each other by said needle shaft in the ready position, each arm being provided at the distal end with a distal guard wall positioned on the shaft of the needle in the ready position and wherein the distal guard walls overlap each other in front of the needle tip when the needle guard is in a blocking position, wherein the needle shaft has a segment slightly proximal to the needle tip, the segment being provided with an increased diameter in relation to the needle tip, and the needle guard having a rear wall from which the arms extend in a distal direction wherein the rear wall includes an opening through which the needle shaft passes, wherein the diameter of the increased diameter segment is greater than that of said opening, and wherein an inner wall of the chamber of the catheter hub is provided with a retaining means in the form of an annular groove by which the needle guard is retained in the catheter hub in the ready position.

2. An intravenous catheter according to claim 1, wherein the distal end of an arm includes a curved protrusion extending to the distal guard wall.

3. An intravenous catheter according to claim 2, wherein the curved protrusion is engaging the annular groove formed in the inner wall of the catheter hub.

4. An intravenous catheter according to claim 1, wherein the increased PA\OPERMLKA\I224490 lsp.do- I3AIE IOERGEFORIOAT 00 O o diameter segment of the needle is a bulge on the needle shaft. An intravenous catheter according to claim 1, wherein the arms each include a narrow portion that extends between a wide distal portion and a proximal wide portion such that the shaft of the needle can pass between intersecting arms.

IN

6. An intravenous catheter according to any one of claims 1 to 5, wherein 0 the distal guard wall terminates in a curved lip engaging the shaft of the needle.

7. An intravenous catheter according to claim 1, wherein there is a hinged arrangement between the proximal ends of the arms and the rear wall.

8. An intravenous catheter according to any one of the preceding claims wherein the increased diameter segment of the needle is positioned within the tubular catheter in the ready position.

9. An intravenous catheter substantially as described with reference to the accompanying drawings.