WO1990005559A1

WO1990005559A1 - Connector

Info

Publication number: WO1990005559A1
Application number: PCT/GB1989/001349
Authority: WO
Inventors: Sven Ragnar Hanas; Ulf Harry Wahlberg; Rolf Emil Karlberg
Original assignee: The Boc Group Plc
Priority date: 1988-11-15
Filing date: 1989-11-15
Publication date: 1990-05-31
Also published as: SE8804110L; SE8804110D0; AU4658989A

Abstract

A connector for releasable connection to a catheter assembly having on the outer surfaces of its hub (1) an abutment (2) includes a housing (4) slideable onto the catheter hub (1). On the housing (4), there is mounted an elongate, latch arm (8) which is arranged parallel to the housing. A fulcrum (11) is located on the housing between the front and the rear end of the housing and between the front end and rear end of the latch arm (8). The rear end (12) of the latch arm (8) permanently bears on the housing (4), and the front end (13) of the latch arm (8) extends beyond and engages the abutment (2) on the catheter hub (1). Such a spacing exists between the housing (4) and the latch arm (8), over a limited length of the housing (4) and the latch arm (8) that the engagement of the front end (13) of the latch arm (8) with the abutment (2) can be released by pressing on the latch arm (8).

Description

CONNECTOR

The present invention relates to connectors for releasable connection to catheter assemblies.

In medical therapy different types of fluids often need to be administered to a patient through a catheter assembly. The infusion process can extend over long periods of time during which no special monitoring or supervision of the infusion process or the infusion equipment is possible.

One example of this is the infusion of insulin by means of a pump into a diabetic patient leading an active life. In this case it is desirable that the infusion process be conducted without the need for any particular supervision of the infusion equipment. This means, among other things, that the connection between the catheter assembly and the infusion pump or a tube from the infusion pump should be reliable such that the patient or a nurse cannot inadvertently undo the connection. It should also be easy to disconnect the pump from the catheter assembly when so desired, for instance, when the patient wishes to have a bath or a shower, and thereafter to connect it again.. It is also desirable to reduce the risks of contamination as much as possible.

It is known from United States Patent No. 4752292, for a system for infusing medication into a patient to include a connection comprising a cap member having a housing slideable over the hub of a catheter assembly between a first latched position and a second position spaced from the hub. The housing incorporates a latching mechanism including a resilient arm extending parallel to the housing and connected to the outside of the housing by a hinge member. The arm has, at- its distal end, a tip which releasably engages an abutment formed on the hub in the first latched position of the housing. A needle is located within the housing with its spiculated end within and spaced from the open distal end of the housing. When the housing is in the first latched position the needle penetrates a self-sealing membrane arranged at the proximal or rear end of the hub.

A particular disadvantage of this known connection is that the proximal end of the arm is free and spaced from the outside surface of the housing. This allows the possibility for foreign matter such as clothing to catch on said free end and disturb the connection.

Furthermore, it is possible to accidentally press on any part of the arm rearwardly of the hinge to release the connection.

It is an object of the present invention to provide a connector for releasable connection to a catheter assembly which can be released only by applying pressure to a pre-selected area of a latch arm which latch arm is formed with a flange to inhibit the possibility of foreign matter entering between the latch arm and the outer surface of the connector.

According to the present invention a connector for releasable connection to a catheter assembly, said catheter assembly including a hub located at the proximal end of the catheter assembly, the hub including an abutment; includes a housing slideable over the hub between a first latched position and a second position removed from the hub, the housing having an elongate resilient latch arm arranged parallel with the housing, a fulcrum extending between the housing and the latch arm between the opposed ends of the elongate latch arm, the latch arm having a lug at or adjacent its distal or forward end which, in the first position of the housing engages the abutment of the hub, the lug being disengagable from the abutment by pressure on the latch arm towards the housing at a location rearwardly of the fulcrum and is characterised in that at its proximal end the latch arm is provided with a depending flange which engages the outer surface of the housing and spaces at least a por on o u crum rom e ou er surface of the housing to permit flexure of said latch arm, the flange also serving to inhibit the entry of foreign matter between said latch arm and the housing.

A particular advantage of the connector subject of the present application is that the connector cannot be loosened from the catheter assembly unless the latch arm is operated in a clearly intentional yet convenient manner by exerting a pressure with a finger on a particular area of the arm.

An embodiment of the invention will now be described, by way of example, reference being made to the Figures of the accompanying diagrammatic drawings in which:-

Figure 1 is a partial cross-section of a connector releasably connected to a catheter assembly;

Figure 2 is a side view of the connector and catheter assembly of Figure 1; and

Figure 3 is a top plan view of the connector and catheter assembly of Figure 1.

As shown, a catheter assembly includes a soft or non-rigid cannula 20 to which at its proximal or rear end there is fixedly attached thereto a hub 1. The hub 1 is formed on its outside surface with an annular abutment 2. Within the hub 1 rearwardly of the cannula 20 there is located a self-sealing membrane 3 which is retained within the hub in a manner known in the art.

The connector includes a hollow generally tubular housing 4 which as shown is fixedly attached to the distal end of a tube 5 which can, for example, extend from an insulin pump. The tube 5 is connected to a steel needle 6 mounted in the housing 4. The housing 4 comprises generally of a first forward cylindrical portion 22, an intermediate tapered portion 24- and rearward cylindrical portion 26. On the upper (as shown) surface of the cylindrical portion 22 there is formed a bead which, as will be explained, acts as a fulcrum 11. Extending outwardly from each side of the housing 4 are mounting pins 10.

Extending longitudinally of the housing 4 along the upper surface thereof is a resilient elongate latch arm 8. The latch arm 8 includes a cross-member 8b from which depend on each side of the housing 4 lugs 9 each having an aperture such that the pins 10 extend through their respective apertures to hold the latch arm 8 against the bead or fulcrum 11 which is positioned in alignment with the pins .10. At its forward or distal end the latch arm 8 is formed with a lug 13 and at its proximal or rear end the arm 8 is formed with a depending flange 12 the free end of which engages the rear of the housing 4 at the cylindrical portion 26.

A recess 14 is provided in the front of the cylindrical portion 22 and extending forwardly from the recess 14 are a pair of fixing wings 15.

Internally of the housing 4 the forward cylindrical portion 22 terminates in an annular abutment 7. Extending rearwardly from the abutment 7 is the tapered portion 24 which blends into the rearward cylindrical portion 26. The rearward cylindrical portion 26 supports the steel needle 6 the forward spiculated end of which is located within the forward cylindrical portion 22.

When it is desired to assemble the connector to the hub 1 the housing 4 is slid over the hub until the rearward face of the hub 1 engages the abutment 7. In this engaged position the spiculated end of the needle 6 pierces the membrane 3 in a manner known per se. , abutment 2 on the hub 1 thereby latching the connector to the hub 1 in a first latched position.

When it is desired to release the connector from the hub 1 the latch arm 8 is pressed at a location 8a between the fulcrum 11 and the flange 12 thereby resiliently flexing the arm 8 and causing the lug 13 to disengage from the abutment 2. The connector can then be disengaged by moving the housing 4 rearwardly from the hub 2 to a second position removed from the hub 1. The tapered portion 24 of the housing 4 extends rearwardly from the fulcrum 11 and thus the connector will only become released from the hub 1 by intentionally exerting a pressure on the latch arm 8 towards the housing 4 at a point along the tapered portion 24 of the housing 4 and the cylindrical portion 26 where the distance between the latch arm 8 and the outer surface of the housing 4 is sufficient to permit the disengagement of the lug 13 from the abutment 2.

The entire needle 6 including the spiculated end is located within the housing 4 which means that the user is protected from contact with the needle.and the needle is protected from contact with or contamination from the user.

It will be observed that the spiculated end of the needle 6 is situated sufficiently far back from the mouth of the housing 4 so as to pierce the membrane 3 only after a sliding fit engagement between the cylindrical portion 22 and the hub 1 thus a guiding engagement is achieved between the front end of the housing 4 and the rear end of the hub 1. In this manner a predetermined penetration by the needle 6 through the membrane 3 is obtained thereby minimising the risk of leakage through the membrane. A further guiding means is provided by the recess 14 and the upper surfaces of the fixing wings 15 which help to promote said guided penetration by the needle 6 through the membrane 3. It will be evident from the above described embodiment that the flange 12 which is in engagement with the outer surface of the housing 4 inhibits or substantially prevents foreign matter in the form of clothing or bed linen engaging the latch arm 8 and thereby disturbing the connection between the hub 1 and the connector.

Furthermore, the tapered intermediate portion 24 of the housing 4 together with the depending flange 12 ensure that the latch arm 8 can only be actuated to disengage the lug 13 from the abutment 2 by an applied pressure over a small selected area of the latch arm 8.

The fulcrum 11 may be located at a position other than that illustrated in the Figures and may comprise means other than a raised bead. For example, the fulcrum may include pivot pin projections provided on lugs similar to the lugs 9.

Claims

1. A connector for releasable connection to a catheter assembly, said catheter assembly including a hub 1 located at the proximal end of the catheter assembly, the hub 1 including an abutment 2, the connector including a housing 4 slideable over the hub 1 between a first latched position and a second position removed from the hub 1, the housing 4 having an elongate resilient latch arm arranged parallel with the housing 4, a fulcrum extending between the housing 4 and the latch arm 8 between the opposed ends of the elongate latch arm 8, the latch arm 8 having a lug 13 at or adjacent its distal or forward end which, in the first position of the housing 4 engages the abutment 2 of the hub 1, the lug 13 being disengagable from the abutment by pressure on the latch arm 8 towards the housing 4 at a location rearwardly of the fulcrum 11, characterised in that at its proximal end the latch arm 8 is provided, with a depending flange 12 which engages the outer surface of the housing 4 and spaces at least that portion of the latch member 8 rearwardly of the fulcrum 11 from the outer surface of the housing 4 to permit flexure of said latch arm 8, the flange also serving to inhibit the entry of foreign matter between said latch arm 8 and the housing 4.

2. A connector as claimed in Claim 1, characterised in that two members extend one on each side of the latch arm 8 to embrace the housing 4 in the transverse direction thereof and engage pins 10 protruding from each side of the housing 4 to hold the latch arm 8 against the fulcrum 11.

3. A connector as claimed in Claim 1 or 2, characterised in that the housing 4 includes an abutment 7 which is adapted to form a stop which is located such that in the first latched position of the housing 4, the lug 13 is permitted to form a snap engagement against the abutment 2 on the hub 1.