WO2000002607A1

WO2000002607A1 - Self-destructing needle holder for injection syringes or the like

Info

Publication number: WO2000002607A1
Application number: PCT/NO1999/000218
Authority: WO
Inventors: Olav Ellingsen
Original assignee: Lifecare As
Priority date: 1998-06-30
Filing date: 1999-06-29
Publication date: 2000-01-20
Also published as: AU4400099A; NO309706B1; NO983035L; NO983035D0

Abstract

A needle holder unit (14) for hypodermic or similar syringes, wherein the needle holder unit when ready for use comprises: a needle holder sleeve (14) with a rear opening adapted for interaction with the outlet end (12) of a syringe housing (2); a needle holder (9) with needle (8) capable of displacement in this sleeve (4); a closely fitting seal (6) located at the downstream side of the needle holder (9); a closely fitting seal (7) located against the downstream end of the needle holder sleeve (4); and a medically acceptable, chemical expanding agent or propellant (5) arranged between the seals (6, 7).

Description

SELF-DESTRUCTING NEEDLE HOLDER FOR INJECTION SYRINGES OR THE LIKE

The present invention relates to a self-destructing needle holder for hypodermic or similar syringes.

To be more specific, the subject matter of the invention pertains to syringes of the type which are known as disposable syringes or self-destructing syringes.

Furthermore, the syringe in principle is of the type which is destroyed on use and where later the part representing a hazard, the hypodermic needle itself, can easily be disposed of as the needle is retracted into a housing on destruction of the syringe.

The majority of so-called disposable or self-destmcting syringes are of the type which in principle comprises a syringe housing, a plunger with plunger rod and plunger head and associated seal and a hypodermic needle.

Disposable or single use syringes are becoming increasingly common, not least because it is becoming more and more usual for individuals suffering from various illnesses, for example-, diabetes, to inject themselves either as a preventive measure or as a therapeutic measure.

However, hypodermic syringes also have a regrettably extensive and unfortunately often repeated use, namely their use by "mainliners", addicts who take drugs by injection, and among this user category major problems have arisen in connection with the reuse of syringes, including so-called conventional disposable syringes.

There is therefore an increasing need for inexpensive and simple, but nevertheless dependable, self-destructing, disposable syringes to help in the battle against the spread of disease by transmission via the bloodstream due largely to the fact that the borrowing and lending of syringes is particularly common among drug addicts. Hepatitis B and AIDS are among the most common infectious diseases of this type.

As indicated above, there are various types of auto-destruct syringes on the market which have some form of frangible member that is broken after the syringe has been used for the first time.

However, it has been found that most of the solutions proposed to date have been either excessively expensive to produce or extremely unsafe to use as it has been possible to manipulate the syringe so as to render it reusable.

As examples of prior art in this field, reference will be made to NO 163 263 and to the somewhat more recent NO 301 523.

Furthermore, US 4,978,343 describes a self-destructing syringe wherein the needle holder is secured by movable catches in the cylinder housing wall and wherein, once the injection has been given, the catches are irreversibly forced out of engagement with corresponding grooves in the needle holder so that the needle holder and needle are withdrawn into the plunger housing when the injection pressure ceases.

Reference will also be made to NO Application 970567 which describes self-destructing syringes wherein means are provided inside the syringe housing which are activated on use of the syringe and which, after the injection has been given, force the needle holder and needle backwards so that the needle is retracted into the syringe housing.

This propellant device may be a retracting spring, but it may also consist of expanding chemical agents.

Reference will also be made to NO Application 975103 which represents a further development of the technology described in P970576. ' 103 makes it possible to equip standard syringe housings with an attachable hypodermic needle which is selected according to need.

The device taught in ' 103 is dependable and neat, although it requires an especially made syringe housing for fitment of the needle holder including the retracting means.

The object of the present invention is to simplify the technology described in '103 so as to allow the use of a conventional syringe housing with an ordinary Luer connector in the end for any type of desired needle length and dimension as the needle holder with retracting means is arranged in a sleeve which acts as a pull-back ram housing and which in a conventional manner is equipped at the rear end thereof with a Luer female element.

Here, it should be pointed out that the invention is not limited to standardised syringes of the Luer type. What is essential, of course, is that the male pan of the syringe housing and the female part of the needle holder sleeve should fit one another.

However, if standardised elements are used, a user equipped with a standardised and conventional stock of hypodermic housings and associated plungers will by virtue of the invention nevertheless be able to obtain great variation as regards desired hypodermic needles.

Thus, in addition to obtaining the desired destruction of the needle unit wherein the needle unit sleeve serves as a disposal container for the now '^"harmless" needle, it is also possible that the syringe housing may be reused, health and safety considerations permitting.

Accordingly, the present invention relates to a needle holder unit for hypodermic or similar syringes and this needle holder unit is characterised in that when ready for use it comprises: a needle holder sleeve with a rear opening adapted for interaction with the outlet end of a syringe housing; a needle holder with needle capable of displacement in the sleeve; a closely fitting seal arranged at the downstream side of the needle holder; a closely fitting seal arranged againt the downstream end of the needle holder sleeve; and a medically acceptable, chemical expanding agent or propellant arranged between the seals.

The invention will now be described in more detail with reference to the accompanying drawings, wherein:

Figure 1 a shows a needle holder unit according to the invention in the form in which it will be distributed;

Figure lb shows a syringe equipped with a needle holder unit according to the invention that is ready for use; - Figure 2 illustrates a syringe equipped with a needle holder according to the invention in use immediately prior to the completion of an injection; and

Figure 3 shows the just used and now destroyed syringe.

Figure la shows the needle holder unit 14 according to the invention including the needle holder sleeve 4 and wherein a protective cover 10 is provided around the needle.

Figure lb shows a syringe that is ready for use comprising a syringe housing 2 with plunger rod 1 and plunger 3.

A needle holder unit 14 according to the invention has now been placed on the outlet end 12 of the syringe housing.

The needle holder sleeve 4 has been mounted on the syringe end piece 12 and the protective cover 10 has been removed, thereby exposing the needle 8.

Figure 2 illustrates the situation after an injection has almost been completed. The plunger 3 in the syringe housing 2 has been moved into a position very close to its end position.

In addition to injection liquid thus being forced out through the needle 8 in a conventional manner, a small amount has been forced past a needle holder 9 and a closely fitting seal 6, thereby allowing a small amount of moisture to come into contact with a chemical expanding agent 5.

This can be accomplished in various ways, for example, by forming the needle holder 9 as shown in the inset figure in Figure 2, and also by designing the seal to have, for example, reflux valves or the like.

Another closely fitting seal 7 is preferably provided for downstream sealing.

On expansion of the chemical propellant 5, preferably based on carbonate and formic acid, the seal 6 and the needle holder 9 will be forced back into the needle holder sleeve 4.

This sleeve, in the upstream end thereof, is preferably equipped with an internal groove 13 at a distance from the downstream end wall which essentially corresponds to the length of the needle 8.

Figure 3 shows the situation after full expansion of the chemical propellant 5.

The whole needle holder sleeve 4 has been filled with gas 11 , the seal 6 has pushed the needle holder 9 backwards and owing to a suitable design as indicated in Figure 2, the needle holder 9 will expand in the radial direction and come into engagement in the internal groove 13, thereby locking the needle 8 in the needle holder sleeve 4.

This "destroyed" unit can now be disposed of in a secure manner and the syringe housing and accessories can, if so desired or if possible, be reused. Of course, the retracting means may conceivably be in the form of mechanical means, for, example, a retracting spring, as described, for example, in NO Application 970576, a possibility of this kind being within the scope of the invention, but where the preferred embodiment uses a chemical propellant such as carbonate and citric acid or other crystalline acids, for example, tartaric acid.

The invention ensures safe destruction of a syringe, with the possibility of reusing the one part whilst the destroyed part can be disposed of simply and safely, and at the same time it provides good possibilities for varying the type of syringe according to need.

Claims

P a t e n t c l a i m s

1.

A needle holder unit (14) for hypodermic or similar syringes characterised in that when ready for use it comprises: a needle holder sleeve (4) with a rear opening adapted for interaction with the outlet end (12) of a syringe housing (2); a needle holder (9) with needle (8) capable of displacement in the sleeve (4); a closely fitting seal (6) arranged at the downstream side of the needle holder (9); - a closely fitting seal (7) arranged against the downstream end of the needle holder sleeve (4); and a medically acceptable, chemical expanding agent or propellant (5) arranged between the seals (6, 7).

2.

A needle holder unit according to claim 1 , characterised in that the chemical expanding agent or propellant (5) is based on carbonate and a crystalline acid such as citric acid, tartaric acid and the like, and/or an expandable polymer or other chemicals which are gas-generating in the presence of moisture.

3.

A needle holder unit according to claims 1 and 2, characterised in that the needle holder sleeve (4) in the upstream end thereof is equipped with an internal groove (13) at a distance from the downstream end wall which essentially corresponds to the length of the needle (8).