WO1989012474A1

WO1989012474A1 - Safety device for hypodermic needles

Info

Publication number: WO1989012474A1
Application number: PCT/US1988/002053
Authority: WO
Inventors: J. Paul Jones
Original assignee: Jones J Paul
Priority date: 1988-06-21
Filing date: 1988-06-21
Publication date: 1989-12-28

Abstract

An inexpensive add-on device to help prevent any user of hypodermic syringes from having an accidental ''stick'' from an exposed needle. Two round discs (1, 4), with a connecting strap (3), are formed from a sheet of soft plastic. The first mounting disc (4), with a suitable yielding aperture (5), is pressed on to the syringe cylinder (6) up to the hilt; and a second shielding disc (1) is pressed on to the needle cover (8), up to its hilt, before the hypodermic needle (10) has been uncapped or issued to the user. When the needle (10) is uncapped for use, the cap is retained by th connecting strap (3), so it cannot be lost or forgotten. When the needle is recapped for disposal, the limited length of the connecting strap (3) prevents the needle from being approached head-on; and the second disc (1) shields the holding finger tips.

Description

SAFETY DEVICE FOR HYPODERMIC NEEDLES

BACKGROUND

It has been estimated by the Bio edical Business Inter¬ national organization that there are close to one million ac¬ cidental hypodermic needles sticks or scalpel cuts per year among health workers and surgeons. The Occupational Safety and Health Administration estimates that at least 300 health care workers die annually from accidental Hepatitis B infections and complications. Now, the added possibility of contracting lethal blood transferred diseases, such as AIDS, has made the need for new protective methods for the health care workers imperative.

Recently several new products have become available, in response to the dire need. One of these product areas is in the protection of hypodermic needle sets with various forms of slid¬ ing covers. Since this approach adds both complexity and cost to the cost sensitive disposable market, and tends to obsolete the many hypodermic types already in production, it can be pre¬ dicted that this approach will be very slow to take on.

There are injection systems that do not require the syringe needle. Most of these systems propel the medication, at high velocity, through a small orifice that is capable of penetrating the skin. However, these reusable type units require special disposable ampules for the medication; and the reusable units would have to go through a steril zation process between patients, when lethal blood diseases are present. Most phys¬ icians, when dealing with lethal diseases, prefer the disposing of all units that are utilized for each patient; and especially if the disposables can be made nexpensively.

It is, therefore, one object of this invention to provide an inexpensive add-on safety device for the disposable syringes that make up the majority of all hypodermic units used in hos¬ pitals and clinics; and which are presently in stock and in production.

The records of causes for accidental "sticks" from the needle on hypodermic syringes, reduce to the following reasons;

1. The majority of accidental "sticks" occur while recapping the needle on a used syringe. When the syringe ancf cap are held at an average distance, a very small error in depth perception can cause the person to miss the 3/16" hole in the cap, and prick one of the holding finger tips.

2. Fear of the capping danger can cause persons to discard the syringe with an exposed needle. If the non-capped syringe were . to find its way into trash bags, the needle could protrude from a bag, and "stick" an unaware disposal person.

It is , therefore, a specific object of this invention to provide a single add-on method to circumvent the basic problems of (1) exposed finger tips during the recapping process, (2) being lost or forgotten during usage and (3) difficulty in spotting uncapped syringes with exposed needles.

The invention provides a shield for the finger tips of the person who is recapping the needle after use. During use, the shielded cap remains tethered to the syringe by a flexible strap which, by its limited length, forces the person who is recapping the needle to approach the exposed needle from the side; while the finger tips that are grasping the cap are protected by a circular shield.

The inexpensive units may be installed by the manufacturer of the syringes, or the shield may be added to capped syringes, in the stock room, before being dispensed. Three basic shield sizes fit the syringe sizes which constitute over 90* of hos¬ pital usage.

The design of the invention, which provides the many safety features, will be more clearly defined with the following Figures and operational description:

Figure ± Shows an actual size blank of a typical shield unit, consisting of the shield and finger pad discs with associated apertures; and the connecting strap.

Figure 2A Shows the finger shield and finger pad during their application to a capped syringe.

Figure 2B Shows a capped syringe, with the complete safety device installed and ready for use.

Figure .3 Shows a typical equipped syringe during use, with the needle cap and shield tethered by the connecting strap.

Figure 4_ Shows an equipped hypodermic syringe during the re¬ capping process, wherein the limited strap length restricts movement of the cap and finger shield to the side of the needle.

OPERATIONAL DESCRIPTION

With reference to Figure 1, the finger shield invention is shown actual size; this particular example being the size for a standard 3cc syringe. The circular disc 1 is the Finger Shield, and the Aperture 2 is slightly less than the Open End 9 diameter of the Needle Cap 8 for which it is designed. Both the Finger Shield disc 1 and the Finger Pad disc 4 are connected by a Strap 3 , which is a specific length for each specific Syringe.

The Finger Pad 4 is of the same general size as the Finger Shield 1; however, it has an Aperture 5 which is slightly less in diameter than the Syringe Housing 6 for which it is designed. It is a property of the basic plastic material used - for ex¬ ample .040 inch thick polyethylene sheet - that allows the Apertures 2 and 5 to expand when the safety device is forced on to both the Needle Cap 8 and the Syringe Housing 6, as depicted in Figure 2A. The undersized apertures 2 and 5 maintain a good compressive fit on both the Needle Cap 8 and the Syringe Housing 6, when they are forced to the open end of the Cap 9 and the Piston End 7 of the Syringe Housing 6, respectively. The final installed positions of both the Finger Shield 1 and Finger Pad 4 are shown in Figure 2B, with like numbers indicating like parts.

The length of the Strap 3 is accurately determined to just allow the Needle Cap 8 and the affixed Shield 1, as shown in Figure 2B, to reach the End of the Needle 14; when the cap and shield are being removed. The outward movement of the Needle Cap 8 , when being removed, travels away and to the side of the needle point. This limited Strap length, will play a more im¬ portant role in avoiding accidental "sticks", during the recap¬ ping procedure; which will be more fully described in another section, below.

Figure 3 shows a typical hypodermic syringe after it has been uncapped and ready for use. The Needle Cap 8 and the Finger Shield 1 remain tethered to the Finger Pad 4 on the Piston 13 end of the Syringe 6. This tethered cap may cause some annoyance to the user; however, it is only the small degree of annoyance that is necessary to maintain the awareness level of the user when it is time to recap and dispose of the used syringe and needle. The tethering obviously eliminates the possiblity of the cap being lost between uncapping and recapping of the syringe and needle.

The recapping of the needle, which is shown in Figure 4, is ordinarily the most dangerous action, without the installed in- vention. Most of the accidental sticks ordinarily occur during the recapping because of very slight misalignment . It is the primary goal of the invention to prevent the user of the hypo¬ dermic from approaching the needle head-on; and to provide a shield for the two or three fingers that may be used to grasp the needle cap during the recapping operation.

When the user grasps the shielded and tethered Needle Cap 8 and attempts to move the Open End 9 of the cap to the end of the needle 14, the connecting Strap 3 limits the distance the Finger Shield can be moved, to the point where the Cap Opening 9 is just opposite the needle tip, when^" the shield s sti1 para!lei to the axis of the needle. It is virtually impossible for the user to maneuver the cap and shield to approach the needle head- on, so the "natural" action is to lay the needle tip against the face of the Cap Opening 9 , and roll the cap opening and shield over the End of the Needle 14; and then to complete the closing of the Cap 8 on the end of the Syringe Housing 6.

It is important for any safety device to not require elab¬ orate instructions - either written or oral ; because both of these communications can break down, or simply not be present.

The invention has been tested on persons with all levels of intelligence and professional training, without any instruction whatsoever. All persons quickly found the correct and only way to apply the needle cap; and with the protection of the Finger Shield 1 for the fingers used. There is an additional feature gained when the invention is applied to a hypodermic syringe. Ordinarily there is a pair of finger tabs at the piston end of all syringe housings, which are used to grasp the syringe with the first and middle fingers, while depressing the piston with the thumb. These small oppos¬ ing tabs are usually of minimal size, and they require orienta¬ tion of the tabs accross the holding fingers to maintain a grip. When the Finger Pad disc 4 is applied to the Syringe Housing 6, it is actually used as a" retaining ring"; however, it does in effect become a much enlarged finger pad, that overlaps the small original tabs. The added circular Finger Pad 4 does not require orientation, and it is much more comfortable and secure to hold.

SUMMARY

The Hypodermic shield invention provides an easy to implement method for the prevention of accidental used needle "sticks", that now occur routinely in hospitals; and which have become a deadly hazard for all persons that may be handling hypodermic needles after use on a person with one of the lethal blood diseases. In addition, the inexpensive add-on device can be attached to all presently used disposable syringes, either by the manufacturer, or in stockrooms before dispensing.

Claims

THE CLAIMS

1. In combination, a hypodermic syringe and a device for preventing needle sticks:

an annular shaped finger shield having a shield aperture mounting the shield on the cap of the syringe adjacent the open end thereof with the shield surrounding the cap;

an annular shaped finger pad having a pad aperture mounting the finger pad on the housing of the syringe adjacent the piston end thereof with the pad surrounding the housing;

a strap connected between the finger shield and the finger pad;

said finger shield, said finger pad and said strap being made from flexible plastic material;

the length of said strap providing for a cap removal condi¬ tion by that the cap can be disengaged from the housing and moved outwardly along the hypodermic needle axis only until the shield aperture is adjacent the tip of the needle, in which position the cap can be swung away from the tip of the needle ; and CLAIM 1 continued

the length of the said strap providing for a cap replacement condition by that the cap be moved in the same direction as the hypodermic needle axis only until the shield aperture is adjac¬ ent the tip of the needle, in which position the cap can be swung to a position for movement along the needle axis for re¬ engaging the cap with the housing.

2. For a hypodermic syringe, and add-on device for preventing needle sticks;

an annular shaped finger pad having a pad aperture, the pad aperture providing for the finger pad to be placed on and around the housing of a hypodermic syringe and moved to a position adjacent the piston end of the housing;

an annular shaped finger shield having a shield aperture providing for the finger shield to be placed on and around the needle protection cap of a-hypodβrmic syringe and moved to a position adjacent the open end of the cap;

a strap connecting said annular shaped finger shield and said finger pad; and

said finger shield, said finger pad, and said strap being made from flexible plastic material.