WO1999020322A1

WO1999020322A1 - Sterile adapter

Info

Publication number: WO1999020322A1
Application number: PCT/IL1998/000511
Authority: WO
Inventors: Eli Matalon
Original assignee: Vascular Technologies Ltd.
Priority date: 1997-10-20
Filing date: 1998-10-19
Publication date: 1999-04-29
Also published as: AU9559498A; IL122005A0; IL122005A

Abstract

A sterile adapter to be used with syringes or intra-vascular needles is provided. The adapter includes a body (1) and a vent (10). The body (1) has a male end (3) to enable the mounting of the adapter to a needle or the like, and for mounting the adapter to a male/female end (5). The vent (10) establishes communication between the inner side of the adapter and the atmosphere and is adapted to release trapped air.

Description

STERILE ADAPTER

FIELD OF THE INVENTION

The present invention relates to a sterile adapter to be used with syringes or intra-vascular needles.

BACKGROUND OF THE INVENTION

A device for identification of penetration by an intra-vascular needle into a blood-conducting vein or artery is based on recognition of the pressure within the blood vessel. It is expected that when the needle punctures the second wall of the blood vessel, part of the blood which entered the needle will be absorbed by the tissue, and consequently the decrease of the pressure will be recognized. However, in some cases the decrease of the pressure is not fast enough. The pressure within a blood vessel can be measured by means of any kind of blood pressure indicator which is attached to the proximal end of the needle. However, there are a number of problems with this:

When an intra-vascular needle has entered a blood-conducting vein or artery, the blood does not enter the syringe to its full length but only to its free distal end. This occurs because the air which is locked within the needle has no vent to escape and is compressed within the needle. In cases of very thin needles, after the needle has been removed from the blood vessel a phenomenon of the capillarity of the needle occurs, namely, the pressure within the needle remains. (This capillary phenomenon is reduced when the diameter of the needle is larger.) Due to this phenomenon it is not possible to detect double puncture of a blood-conducting vein or artery.

The use of an adapter for the pressure release at the distal end of the needle could solve the problem.

DESCRIPTION OF THE INVENTION

In order to neutralize the phenomenon of capillary pressure when the needle is removed or is not within the blood vessel, it is proposed to add means for releasing the pressure within the needle in a controlled manner. Consequently, when the needle is not within or removed from the blood vessel, the pressure within the needle will be reduced.

The means for releasing the pressure will not allow any liquid

to be released from the needle, since it is mounted at the distal end of the

needle. The diameter there is relatively large, and consequently the

capillary phenomenon will not exist. Liquid which reaches the point where

air is released will be sealed.

As long as the distal end of the needle is under pressure, the

air locked within the needle is slowly released through the vent. Since the

rate of flow of blood into the needle is larger than the rate of release of

locked air, the blood pressure will be sensed by the appropriate sensor.

When the needle is not within the blood vessel, such as in the case of

double puncture, the flow of the blood into the needle stops, which will be

sensed by the appropriate sensor.

Since the rate of release of the air through the vent is quite

slow, the needle may be fully penetrated into the blood vessel before the

blood reaches the vent and possibly seals it.

The vent could be effected either by hydrophobic material or by

means of small slots or bore as will be indicated. According to^~ the invention the adapter comprises a body

having a luer male end to enable the connection to a needle, a male/female

end to enable the connection to a sensing device, and a vent which

establishes communication between the inner side of the adapter and the

atmosphere, adapted to release locked air.

The invention will now be described with reference to the

annexed drawings in which:

Figure 1 is a cross-section of the adapter where the vent is an aperture sealed with hydrophobic material. Figure 2 is a cross-section of the adapter where the vent comprises longitudinal narrow slots.

Figure 3 is a cross-section along line A-A of Figure 2.

Turning first to Figure 1 the adapter according to the invention comprises a body 1 having a male end part 3 and a male/female end part 5. In this embodiment an aperture 7 is provided intermediate both ends. The aperture 7

and outlet 9 are stuffed with a porous hydrophobic material 10 which enables the escape of air but prevents the outflow of blood, hence the sterility of the adapter. Instead of aperture 7 a small diameter bore could be provided.

In the embodiment seen in Figure 2 and 3 the vent is made of longitudinal narrow slots 11 provided on the outer circumference of male end part

3 of the adapter. The narrow slots allow the air to escape in the space between the outer side of the male end part 3 of the adapter and the inner side of the needle. It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the invention is defined by the claims which follow:

Claims

1. An adapter to be used with needles or syringes which comprises: a body having a male end to enable the mounting of the adapter to a needle or the like, and to a male/female end; and a vent which establishes communication between the inner side of the adapter and the atmosphere said vent being adapted to release trapped air.

2. An adapter according to claim 1 wherein said vent is an aperture provided intermediate both ends of the adapter.

3. An adapter according to either of claims 1 and 2 wherein said aperture and the outlet of the adapter are provided with hydrophobic and porous material.

4. An adapter according to claim 1 wherein the circumference of said male end part is provided a plurality of longitudinal narrow vent slots.