ASSEMBLY OF NEEDLE AND PROTECTOR

Abstract: An assembly of a needle and a device for protecting the needle tip is disclosed. The assembly (10) comprises an elongate housing (11) which mounts the needle (22). A needle guard (23) is slidably mounted within the housing and is adapted to be moved forward along the needle. Following use, the needle and housing are retracted and the needle guard becomes permanently locked with the housing while it occludes or covers the needle.

Description: This invention relates to a new and improved assembly of a needle and a protective needle guard therefor. Following use, needles are usually broken, and discarded as waste. However, there is always a small possibility that the discarded needle points may inadvertently stick or scratch medical health personnel. Also, it is desirable that persons who use or come in proximity with used needles should not have to contact them prior to, or subsequent to their use. This is becoming of increasing importance in reducing accidental infections from patients who have HIV (AIDS) virus, hepatitis, and other infectious diseases. There is presently on the market a device sold by ICU Medical which functions to almost completely enclose the needle subsequent to use. However, the device does not provide a housing or protective cover for the needle tip. This, of course, leaves open the possibility of a health care worker being accidentally stuck or scratched. U.K. Patent Specification 2178322A discloses a safety device for a hypodermic syringe having a sheath for encapsulating a needle once used. The document describes an assembly of a needle and protector therefor, comprising: (a) an elongate outer housing providing sidewalls, and a first part of a detent means defined thereon; (b) a needle connected to the housing and projecting through the forward open end of the housing; and (c) a needle guard slidably mounted relative to the housing, the needle guard being provided with a second part of said detent means arranged to be complementarily engageable with said first part of said detent means. According to the invention, the needle guard is slidably mounted within the housing, and is provided at its forward end with a pull tab, and also a hub support defining a bore therein, wherein a luer-lock type locking hub and catheter are mounted on the hub support, with the needle aligned within the hub support, hub and catheter, and projecting through the catheter to expose a tip thereof; such that following insertion of the needle and a catheter into a patient, the housing and attached needle are adapted to be retracted from the patient, and the needle is adapted to be retracted into the needle guard thereby enabling the walls of the housing to slide in relation to the needle guard until the first and second parts of said detent means are biased into complementary locking engagement with one another, the needle guard being sized to completely enclose the needle upon locking with the housing and the hub and catheter remain with the patient whilst the housing and enclosed needle are separated from the hub, catheter and patient. Preferred embodiments of the invention will now be described with reference to the accompanying drawings, in which: Fig.1 is an external, perspective view of an exemplary assembled device of this invention; Fig.2 is an external, perspective view, partly cut-away, showing the slidable needle guard portion of the assembly; Figs.3 and 3A are cross sectional, upper views of the device, with the needle guard in the retracted position, with and without an attached syringe; Figs.4 and 4A are cross sectional, upper views showing the needle guard in the extended position covering the needle, and being locked into its associated housing; and Figs.5 and 6 are sectional views in side elevation of a further embodiment showing a retractable needle support and attached needle, the support providing a handle with detent slots for engaging detent means on an associated needle guard. Referring to Figures 1 to 4, an assembly 10 comprises a rectangular, elongate housing 11 of clear plastic such as injection moulded polycarbonate or polystyrene. The clear plastic enables flashback to be readily observed. The housing provides enclosure walls 12 defining inside surfaces 12a, and a magnification portion 13 to better enable viewing blood flashback. At its closed end, a rear mount 14 with extension 14a inside the housing are adapted to mount and secure a needle. An open end 15 is defined by the housing through which the needle guard moves, and through which the needle projects. Fingergrip ridges 16 are formed on the exterior of the walls, and these also serve to a certain extent to reinforce the housing structure. Stop wings 17 are provided at the open end 15 of the housing along with detent slots 18, the latter being designed to engage the needle guard. A needle 22 having a bevelled tip 22a is secured within the housing 11 on the extension 14a, the needle projecting through the open end 15 of the housing. A needle guard 23 is slidably mounted within the housing 11, and provides a forwardly located pull tab 24 and outwardly bent locking ears 25, 25. When the needle guard 23 is positioned in the housing 11, the locking ears 25, 25 are biased inwardly by contact with the inside surfaces 12a of the housing walls 12. The biasing is accomplished by using a plastic construction such as polystyrene, polycarbonate etc., which have flexible properties in a thin wall form. A forward bore element 26 is provided by the needle guard through which the needle 22 projects. As shown in FIGS. 3 and 4, the combined effect of the fixed rear mount 14, extension 14a and forward bore 26 enables the needle to be maintained stiff and in alignment when it is thrust forward into a patient. Since the extension 14a is manufactured of a plastic material, this represents far less expense than if the extension were to be manufactured of a stainless steel, as shown in the embodiments of FIGS, 3A and 4A. A rear bore 27 connects the housing 11 with a hypodermic syringe 28. If the syringe 28 is eliminated, the device takes the form shown in FIGS. 3A and 4A. A luer-lock hub 30 and catheter 31 are mounted on the bore element 26 with the other catheter covering the needle, and only the needle tip 22a being exposed. A cover 32 having wings 33 is usually employed to cover the luer-lock hub, catheter and needle to reduce loss of sterility and protect the user from the needle 22. The cover 32 is secured to the device by a light interlock with the wings 17 of the housing 11. When the device is to be used, the cover 32 is removed, as shown in FIG. 2, and the needle 22 and catheter 31 are inserted into a patient. With the catheter remaining in the patient, the needle can be withdrawn by pressing against the forward tab 24 while retracting the housing 11 and attached needle 22. Consequently, the needle guard 23 will remain stationary while the locking ears 25, 25 ride along the inside surfaces 12a of the walls 22 of the housing. The locking ears will then snap into their normally outwardly extending configuration (with a clicking sound) and lock into the detent slots 18 of the housing 11. This operation is shown in FIGS. 4 and 4A. The needle guard is, of course, sized to accommodate the appropriate length of needle within the enclosure of the guard and within the forward bore element 26, as shown in FIG. 4, or within the enclosure of the guard. Since the needle guard and housing are now permanently engaged, the device can be disposed of without becoming a subsequent source of injury or infection to health care personnel. It will also be appreciated that when the needle is retracted from the patient, it will pass through the catheter and directly into the needle guard enclosure without any exposure to personnel, and this represents an additional safety feature. Figs. 5 and 6 illustrate another embodiment of this invention, and show a needle guard 60 providing outwardly biased, rear locking elements 61, 62 and a hollow bore 63 in fluid connection with a needle. A hydrophobic plug 64 prevents blood flow beyond the bore 63. The exterior of the needle guard 60 defines a longitudinal side wall 65 which terminates in a catheter mount 66 having a bore 71; a catheter hub 74 and attached catheter 75 are mounted thereon. A handle 67 defining gripping ridges 68 on its exterior surface is mounted for movement on the side wall 65. The needle handle defines slot elements 69, 70 which are adapted to engage the rear locking elements 61, 62 of the needle guard 60. The needle handle 67 provides a hollow centrally disposed needle support member 72 on which a needle 73 is mounted. When the needle handle is in the forward position, as shown in Fig. 5, the needle 73 projects through the bore 71 of the hub 66, making a close fit therewith; this provides a good support for the needle. After needle puncture, and needle withdrawal from the patient, the needle handle 67 and attached needle 73 are retracted along the needle guard until the outward biasing of the rear locking elements 61, 62 of the needle guard engage the slot elements 69, 70 thereby locking and recessing the needle well within the needle guard. The catheter hub 74 and catheter 75 remain with the patient for connection to, say, an I.V. unit. A wide range of needle sizes may be employed in the assembly, and typically range from about 12 - 26 gauge. Also, many types of catheters may be used insofar as materials are concerned, such as expandable, hydrophillic polymers, teflon, pvc, nylon, polyurethane, etc., which are all commercially available.

Claims: An assembly of a needle and protector therefor, comprising: (a) an elongate outer housing (11,67) providing sidewalls, and a first part of a detent means (18,69) defined thereon; (b) a needle (22,73) connected to the housing and projecting through the forward open end of the housing; (c) a needle guard (23,60) slidably mounted relative to the housing, the needle guard being provided with a second part (25,61) of said detent means arranged to be complementarily engageable with said first part of said detent means characterised in that the needle guard is slidably mounted within the housing and is provided with a pull tab (24) at its forward end, and the needle guard further providing at its forward end a hub (26,66) support defining a bore therein, wherein a luer-lock type locking hub (30,74) and catheter (31,75) are mounted on the hub support, with the needle aligned within the hub support, hub and catheter, and projecting through the catheter to expose a tip (22a) thereof; such that following insertion of the needle and a catheter into a patient, the housing and attached needle are adapted to be retracted from the patient, and the needle is adapted to be retracted into the needle guard thereby enabling the walls of the housing to slide in relation to the needle guard until the first and second parts of said detent means are biased into complementary locking engagement with one another, the needle guard being sized to completely enclose the needle upon locking with the housing and the hub and catheter remain with the patient whilst the housing and enclosed needle are separated from the hub, catheter and patient. An assembly according to claim 1, wherein the second part of the detent means comprises resilient outwardly biased ears provided on the needle guard for engagement with complementary recesses provided on the sidewalls of the housing. An assembly according to claim 1 or claims 2, wherein the housing has a rearwardly closed end with the needle being attached thereto so as to be in communication with a hypodermic syringe via a bore provided in the closed end. An assembly according to claim 1 or claim 2, wherein the housing is in the form of a hollow handle mounted on the needle guard.

Inventors: CHOKSI, PRADIP V., LUTHER, RONALD B.
Applicants: LUTHER MEDICAL PRODUCTS, INC.
Application year: 1988
Main classification: A61M5
IPC codes: A61M25, A61M5