GB2457258A

GB2457258A - Needle safety sheath

Info

Publication number: GB2457258A
Application number: GB0802267A
Authority: GB
Inventors: Nicholas Jones-Ford
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-02-07
Filing date: 2008-02-07
Publication date: 2009-08-12
Also published as: GB0802267D0

Abstract

The sheath has guiding means 5, 8 adapted to guide at least part of the needle 1 towards a receiving cavity 6. The sheath may comprise a cap 12 for attachment to the sheath once the needle portion 2 is inside. The guiding means may comprise a V-shaped notch 8. The needle portion 2 may be prevented from rotating when in the sheath by ridges 11 on the inner surface.

Description

A Sheath

Field of the Invention

The present invention relates to a sheath, and more particularly, but not exclusively the invention relates to a sheath for sharp implements; more particularly the invention relates to needles and specifically hypodermic needles.

Background

In the medical profession hypodermic needles are widespread and of fundamental importance. The vast majority of medical needles are used only once and then must be disposed. Needle disposal is necessarily therefore a highly frequent task. However disposal of used hypodermic needles has in the past typically involved successfully isolating the used needles whilst maintaining minimum contact, avoiding getting stuck by the needle point.

These needles were then typically placed in a secure container which was subsequently incinerated.

Before a used needle was permanently disposed there was therefore a continuing risk of needle stick injuries to medical professionals and other individuals. This sort of injury has the possibility of leading to contamination from the contents of the needle and the needle point, of particular risk regarding HIV and hepatitis.

Needles are also commonly used in chemical, biological and microbiological fields. It will be appreciated that in each of these fields there is risk of needle stick injuries and contamination with substances in the syringe, as there is with the medical profession.

Previously any users would have to be extremely careful with needles before placement in a suitable container for permanent disposal.

Unlike other needle uses, needles used in dentistry are often not single use.

Where a patient needs increased painkilling the needle will be reused to increase the dosage. In times between doses the needle is redundant.

However, as it may potentially be required again, it must be kept sterile, free from contamination and cross-infection, and safely secure.

There is therefore a need for a safety device, which is able to give protection to the user and anyone else who comes within close proximity of the needle, particularly when the needle has been used and is contaminated.

This is allied to the wider need to provide needle use safety and simplicity, and provide a means to expeditiously dispose of needles.

Prior Art

Various existing hypodermic needles have a cap which may be replaced over the needle after its use. The replacement of the cap required a degree of dexterity in placing the narrow tip of a needle into a relatively small aperture of the cap. If a user were tired, distracted and/or were to miss the aperture when placing the cap over the needle there was a risk of a needle stick injury, with the disastrous result that the needle or syringe could contaminate the user. This risk was increased in busy hospital environments or high pressure environments. In such situations there was the increased danger of distraction or passing people who could knock into someone attempting to re-insert a needle into its protective cap.

United States Patent US-A1-6 796 968 (Ferguson et al) discloses a safety device for hollow bore medical needles, the device comprising a retractable sheath connected to a hub, which is attached to the syringe. The sheath slid over the needle by way of two segments connected by a hinge. A latch enabled the sheath to be locked and unlocked if the needle was required.

Though the safety device protected the user from injury when the needle was in use, it was ineffective once the needle had to be disposed of, in part due to the inability to sheath it from the user once removed from the syringe.

Published European Patent Application EP-A-0 460 821 (Hollister) discloses a safety device for a needle, comprising a base flexibly connected to a housing which is positioned to envelope the needle and a means to lock the housing in place. The base comprises two portions: one connected to the syringe; the second connected to the needle. A disadvantage of this device was that on disposal of the needle, it was necessary to separate the needle from the syringe and this was difficult due to the base portions being attached to one another each.

Published International Patent Application WO-A-03 006 082 (Hwang) discloses a needle sheath for medical devices comprising: a hub, a needle cannula, having a proximal end and a distal end and a lumen. The proximal end is attached to the hub which is connected to a medical device, such as a syringe. The distal end sheaths the point of the needle and is attached to the proximal end by a hinge, which has one or more locking members. The disadvantage of the needle sheath was that it prevented the release of the needle without exposing the point of the needle from the medical device thereby preventing it from being disposed safely.

It is an object of the present invention to overcome the aforementioned problems by providing a sheath that is easy to place over a used hypodermic needle in order to reduce the risk of needle stick injuries, facilitate in the disposal of used needles and provide a safe and secure means of holding needles whilst in use.

Summary of the Invention

According to the present invention there is provided a sheath for encapsulating a pointed implement comprising: a female portion, capable of receiving a male implement portion and guiding means adapted to guide, in use, at least part of the male portion towards a receiving cavity in the female portion.

In a preferred embodiment the guiding means comprises a V-shaped recess cut or formed into the female receiving portion, wherein the recess provides a gully into which a needle point is guided, as it is placed in and urged into the entrance to the cavity. This gully may also be formed with other convergent shapes.

Needles, in use are typically connected to syringes. The syringes are typically as currently used or in an alternative may be specially configured for compatibility with the needles.

The syringe and needle may be configured to be attached to each other wherein a mechanism is employed to simply and firmly connect the two components. In a preferred embodiment the mechanism comprises a screw and threaded portion. In the dental profession such a screw fixing is common in related items. It may comprise a clip. Most needles in medical use are currently push-fit. Although all needles should be sheathed before being disposed of in a sharps bucket, in practice they are not and the present invention facilitates this process.

Brief Description of the Drawincis

Preferred embodiments of the invention will now be described, by way of example only and with reference to the Figures in which: Figure 1 shows an isometric view of a needle assembly comprising a male portion, a female portion and a cap top; and Figures 2A, 2B and 2C show overall, diagrammatical views of the needle and sheath in use.

Detailed DescriDtion of the Preferred Embodiments of the Invention Figure 1 shows an overall view of a needle 1, for example of the type used as a hypodermic syringe in dentistry or by physicians. Needle us supported by and passes through the centre of male portion 2. Male portion 2 is in the form of a screw cap, with an internal thread. Male portion 2 is received into female portion 4 and engages therewith by way of an interference fit.

Female portion 4 may be supplied in two parts, namely a female portion 4 and an end cap 12. The female portion 4, prior to use, is connected to the end cap 12 by way of a tamper evident seal 3. This ensures that the female portion is sterile as it will later receive (and possibly re-receive) the male portion 2, in which the needle I is located.

Prior to use seal 3 is broken and female portion 4 may then be separated and is able to receive the male portion 4 with a needle. In a preferred embodiment the seal 3 may comprise a paper seal capable of being separated by ripping.

Figure 1 also shows a guiding means 5, which is in the form of a V-shaped cut in the wall 9 of the female portion 4. The V-shaped cut may be formed integrally with the female portion 4 or it may be cut subsequent to manufacture of the female portion. V-shaped cut 5 leads into cavity 6, defined by the female portion 4, so that in use a needle tip may be directed to a portion where it is rendered safe to insert, as described in greater detail below.

On the male portion 2 there is shown a series of angled faces 13 to interfere with like faces, defined by ridges 11, on an inner surface of the female portion.

These serve to arrest the male portion 2 and prevent relative movement of the male portion 2, about the longitudinal axis of the inserted needle, within female portion 4.

Screw thread 14 located on an inner surface of the male portion, is configured to receive a matching screw thread on a syringe 7, as shown in Figures 2. A collar or stop ring 15 prevents further movement of the needle I into the cavity 6 and this ensures the needle stops short of the end of the cavity, thereby ensuring that the needle is not damaged or contacts any surface.

Mention will now be made to the invention in use, by way of reference to Figures 2 and in particular 2A, which shows the male portion 2, attached to a syringe 7. The female portion 4 is depicted separate from the male portion 2 and being held in a users left hand, whilst the male portion 4 and syringe 7 is being held in the users right hand.

Figure 2A is the first view of a sequence of three views which show how the needle I and syringe 7 are inserted safely into the female portion 4. This may occur after use of the syringe 7. Arrow A depicts an arc indicating the direction of movement of the users right hand (holding the syringe) relative to the left hand (holding the female portion).

Figure 2B, which is a view of the users hand shortly after Figure 2A, shows the syringe 7, more particularly the needle 1 being placed in contact with the guide means 5. When the needle 1 reaches the narrowest point (or apex) 8 of the guiding gully 5, the needle I flexes with any further movement of the users hand. This flexing gives rise to a contact pressure between the needle 1 and a peripheral region of the wall 9 of the female portion 4 that defines the gully 5.

In the action of bringing the needle I into contact with the V-shaped notch 5 of the female portion 4, so that the needle flexes, and by withdrawing the needle by a small amount, the tip of the needle springs into the cavity defined by the female portion. When this occurs and the needle hits the inner wall 9 of the female portion and an audible "click" informs the user that positioning is accomplished and safe insertion is possible. This process may be repeated if the needle is being used a number of times as there is no physical damage to either the needle or the sheath.

Figure 2C illustrates the situation following the audible "click".. The click is audible and can be felt through the gloved hand, therefore the user is aware that the needle I is correctly positioned for insertion into the cavity 6. Once inserted the combination of the angled faces I and 13, and collar 15 militates against inadvertent release of the syringe from the encapsulating female portion 4, even when the syringe is rotated. After the syringe 7 has been unscrewed from the male portion 2, the cap 12 may be placed over the joined male and female portions so as to encapsulate the combined female and male portion with the needle syringe and any fluid or blood retained therein.

Alternatively, or in addition to, cap 12 may be used to close or cover the female portion 4 when the needle is removed, for example when the needle is being used to re-inject a patient a second or subsequent occasion A mechanism or device may be provided to secure the cap 12 when placed upon the female portion. This may consist of a clip mechanism. Alternatively it be a simple push-fit or a screw mechanism.

It is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in

the description or illustrated in the drawings.

It will also be appreciated that the invention is capable of other embodiments and of being practised and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.

The foregoing description is considered as illustrative only of the principles of the invention.

Variation to the above embodiments may be made without departing from the scope of the invention, for example a finger guard may be supplied with or fitted to or as a part of the needle sheath so as to reduce the risk of accidental stick injury to the user or patient.

Claims

Claims 1. A sheath for encapsulating a pointed implement comprising: a female portion, capable of receiving a male implement portion and guiding means adapted to guide, in use, at least part of the male portion towards a receiving cavity in the female portion.
2. A sheath according to claim 1 wherein the male portion is adapted to connect to or receive the implement.
3. A sheath according to claim 2 wherein the implement is a needle, for example a hypodermic syringe.
4. A sheath according to claim 3 wherein the means of connection comprises a screw fitting.
5. A sheath according to any preceding claim wherein the male portion is prevented from twisting about its longitudinal axis when received by the female portion.
6. A sheath according to any preceding claim wherein a cap is provided for the female portion.
7. A sheath according to claim 6 wherein a locking means is provided for locking the cap to the female portion is provided.
8. A sheath according to any preceding claim wherein the guiding means, when in use, provides positive feedback to a user.
9. A sheath according to any of claims 7 or 8 wherein the locking means, in use, gives positive feedback to the user.
1O.A sheath according to claims 8 or 9 wherein the positive feedback is audible.
11.A sheath according to any preceding claim wherein the guiding means comprises a V-shaped recess in the female portion.
12.A sheath according to any preceding claim where the locking means has an irreversible anti-tamper fit.
13. A sheath according to any preceding claim which is in the form of a plurality of sheaths.
14. A sheath according to any preceding claim which has a finger guard.
15.A method of forming a sheath for encapsulating a pointed implement comprising the steps of: forming at least two portions and providing a means of guiding the second portion implement point towards a receiving cavity in the first portion as hereinbefore described with reference to the Figures.
16.A method of forming a sheath according to claim 15 wherein a plurality of sheaths are formed in a single stage.