WO2003090602A2

WO2003090602A2 - Apparatus for shielding a needle

Info

Publication number: WO2003090602A2
Application number: PCT/US2003/012527
Authority: WO
Inventors: Larry Partika; David E. Desalvo
Original assignee: Becton Dickinson And Company
Priority date: 2002-04-24
Filing date: 2003-04-23
Publication date: 2003-11-06
Also published as: AU2003231045A1; WO2003090602A3; AU2003231045A8

Abstract

An apparatus is provided for capturing the tip of an epidural needle (50), which includes a substantially cylindrical body and a curved tip. The apparatus includes a cap (10) having a distal end (12) and a proximal end (11), a top (13) and a bottom (14), and two side ends (15). The side ends (15) provide a gripping surface for a user's fingers. A yoke (20) is disposed on the proximal end (11) of the cap (10). A rigid sleeve (21) is attached to the yoke (20) and extends in a distal direction from the collar. The sleeve (21) may be formed of two distinct collars (27,28) separated by a selected distance. A channel (26) is disposed in the sleeve (21). An arm (23) is attached to the distal portion of the sleeve (21) and extends in the distal direction from the sleeve (21) . A front plate (24) is attached to the arm (23) remote from the sleeve (21) and disposed at the proximal end (12) of the cap (10). An aperture (25) is disposed in the front plate (24) along the axis (31) of the channel (26). The aperture (25) is sized to permit passage of the body (51) of the needle (50) and the tip (52) of the needle there through. The sleeve (21) is sized to permit passage of the body (51) of the needle (50) but to prevent passage of the tip (52) of the needle (50). The length of the sleeve (21) may be increased to improve the performance of the apparatus. Specifically, as the length of the sleeve (21) increases, the requirement for tight tolerances of the sleeve (21) on the body (51) of the needle (50) is reduced. A clip (40) may be included to prevent reemergence of the tip (52) from the cap (10). Further, a tether (200) may be provided to restrict movement of the cap (10) off the needle tip (52).

Description

APPARATUS FOR SHIELDING A NEEDLE

Field Of The Invention

[0001] The subject invention relates to the field of needles, h particular, the invention is related to an apparatus for shielding the tip of a needle after use.

Background Of The Invention

[0002] There are two optional procedures for administering a liquid anesthesia into the epidural space of a spine. In the first procedure, an epidural needle is inserted into the epidural space, and the anesthesia is administered directly through the epidural needle. The second procedure employs an epidural needle to introduce a catheter into the epidural space. The epidural needle then is withdrawn, and the catheter is left in place. The catheter then may be used to administer anesthesia over a longer period of time. [0003] With either approach, once the introducer needle is withdrawn from the patient, it is a "blood contaminated sharp" and must be properly handled. In recent years, there has been great concern over the contamination of clinicians with a patient's blood and a recognition that "blood contaminated sharps" are preferably disposed of immediately. This concern has arisen, in part, because of the advent of currently incurable and fatal diseases, such as Acquired Immunosuppressive Deficiency Syndrome ("AIDS"), which can be transmitted by the exchange of body fluids from an infected person to another person. Thus, contact with the body fluid of an HIN-infected person should be avoided. As noted above, if a needle has been used to place a catheter in the vein of an HlV-infected person, the needle may be a vehicle for the transmission of the disease. Although clinicians are aware of the need to properly handle "blood contaminated sharps," in certain medical environments, such as emergency situations or as a result of inattention or neglect, needle sticks from contaminated needles may occur.

[0004] As a result of the problem of accidental needle sticks by "blood contaminated sharps," various needle shields have been developed. Examples of such shields are disclosed in U.S. Patent 6,004,294 and U.S. Patent Application 09/717,148 (filed November 21, 2000), both incorporated herein by reference. These shields operate by engaging a feature, such as an enlarged diameter portion, formed on the needle. The engaging means may take many forms, such as a spring gate biased to contact the enlarged diameter portion of the needle when the tip of the needle is within the shield. [0005] Due to the particularly delicate nature of the procedure for delivering epidurals, and in view of the relatively long length of epidural needles, caregivers responsible for administering epidurals are particularly sensitive to the design and performance of the epidural needle. Consequently, it is believed that caregivers are reluctant to use epidural needles that are modified to include an enlarged diameter portion because of a change in performance. Further, due to the substantial length of the needle and its delicate structure, it has been difficult to provide a shielding device that can withstand adequate force without affecting the operation of the needle itself.

Summary Of The Invention

[0006] In accord with an aspect of the invention, an apparatus is provided for capturing the tip of an epidural needle. The needle includes a substantially cylindrical body and a curved tip. The apparatus includes a cap having a distal end and a proximal end, a top and a bottom, and two side ends. The side ends provide a gripping surface for a user's fingers. A yoke is disposed on the proximal end of the cap. A rigid sleeve is attached to the yoke and extends in a distal direction from the collar. The sleeve may be formed of two distinct collars separated by a selected distance. A channel is disposed in the sleeve. An arm is attached to the distal portion of the sleeve and extends in the distal direction from the sleeve. A front plate is attached to the arm remote from the sleeve and disposed at the proximal end of the cap. An aperture is disposed in the front plate along the axis of the channel. The aperture is sized to permit passage of the body of the needle and the tip of the needle there through. The sleeve is sized to permit passage of the body of the needle but to prevent passage of the tip of the needle. The length of the sleeve may be increased to improve the performance of the apparatus. Specifically, as the length of the sleeve increases, the requirement for tight tolerances of the sleeve on the body of the needle is reduced. [0007] Certain implementations of this aspect of the invention provide that a clip, such as a leaf spring, is mounted to the sleeve and extends in a distal direction. A tab is mounted to the leaf spring and extends through the axis of the channel when the leaf spring is in an unbiased condition. A hook may be provided at the end of the tab to better engage the tip of the needle. The leaf spring, tab and hook may be stamped from a single piece of metal. The sleeve, arm and front plate may be integrally formed. The clip is preferably disposed completely within the footprint of the cap, whether actuated or not actuated, such that expose of the clip to inadvertent manipulation is reduced.

[0008] In accord with another aspect of the invention, an apparatus is provided for capturing the tip of a needle. At its tip, the needle is curved to form an offset, which results in a tip width that is larger than the cross section of the body of the needle. The apparatus includes a cap having a proximal end and a distal end. A sleeve is fixedly positioned within the cap. A channel extends through the sleeve from a proximal end to a distal end and includes a distal opening located at the distal end of the sleeve. The distal opening is larger than the cross section of the body of the needle but smaller than the tip width. Consequently, the body of the needle may pass through the distal opening but the tip is prevented from passing there through. The sleeve closely contains the body of the needle so that it cannot rotate to permit the tip to slide through the distal opening.

[0009] In accord with another aspect of the invention, an epidural needle assembly includes an epidural needle having a proximal end and a distal end. A needle tip is disposed at the distal end of the epidural needle and is curved to form an offset. A needle hub is attached to the epidural needle at the proximal end. A cap having a proximal end and a distal end is slidingly mounted to the needle and selectively engaged to the needle hub. A sleeve is fixedly positioned within the cap. A channel extends through the sleeve from a proximal end to a distal end. A proximal opening is located at the proximal end of the sleeve. The sleeve opening is sized to permit passage of the body portion of the needle there through but to prevent passage of the tip portion. [0010] Certain implementations of this aspect of the invention provide that a mounting post on the needle hub is selectively engaged to the cap via friction; fingers are mounted to the needle hub near the mounting post such that, when the cap is disposed proximally on the needle, the fingers engage the cap, wherein the fingers include a flanged portion remote from the needle hub that engages the needle hub; a cover is selectively engaged to the fingers and including a rib with a seat wherein, when the cover is engaged to the fingers, the flanged portion of the fingers is disposed in the seat; and a clip is provided for preventing the needle tip passing through the distal end of the cap. [0011] In accord with another aspect of the invention, an apparatus is provided comprising a needle having a substantially cylindrical body portion and a tip portion that extends radially beyond the body portion a predetermined distance, thereby defining a tip width. A cap has a proximal collar and a distal collar. The distal collar has an opening that is aligned with an opening in the proximal collar. The opening in the distal collar is larger than the body portion but smaller than the tip width to prevent the tip from sliding through the distal opening. The opening in the proximal collar is sized to prevent rotation of the needle so that the tip cannot be slipped through the distal opening. The distance between the proximal collar and the distal collar may be increased to reduce the requirement of a close size fit between the proximal opening and the distal opening and the outer diameter of the body portion of the needle. The distal collar and the proximal collar may be integrally formed as part of a sleeve that encloses the needle body. Further, a front plate may be attached to the cap at its distal end having an aperture that is aligned with the openings in the distal collar and the proximal collar. Means may be provided for preventing distal movement of the tip portion through the front plate. Such preventing means may include a leaf spring mounted within the housing that is movable to an unbiased position in which it blocks movement of the tip portion through the aperture.

Brief Description of the Drawings

[0012] Fig. 1 is a perspective exploded view of an epidural needle with a shield in accord with aspects of the invention;

[0013] Fig. 1A is a side elevation view of the tip of the epidural needle depicted in Fig. 1;

[0014] Fig. 2 is a perspective view of the epidural needle of Fig. 1 shown assembled before actuation of the shield;

[0015] Fig. 3 is a perspective view of the epidural needle of Fig. 1 shown assembled after actuation of the shield; [0016] Fig. 3 A is a perspective view of an embodiment of the invention employing a tether, shown assembled after actuation of the shield; [0017] Fig. 4 is a top perspective exploded view of the shield of Fig. 1 ;

[0018] Fig. 5 is a side cut-away view of the epidural needle of Fig. 1 with a safety cover before actuation of the shield;

[0019] Fig. 6 is an isolation view of the shield of Fig. 5, shown mounted on a needle before use;

[0020] Fig. 7 is a cut-away side view of the safety cover of Fig. 5;

[0021] Fig. 8 is a side cut-away view of the epidural needle of Fig. 1 after actuation of the shield;

[0022] Fig. 9 is an isolation view of the shield of Fig. 8, shown mounted on a needle after use;

[0023] Fig. 10 is an isolation view of the shield of Fig. 8, shown mounted on a needle after use, depicting the operation of the shield despite rotation of the needle; and

[0024] Fig. 11 is an isolation view similar to Fig. 9, depicting another implementation of the invention.

Detailed Description

[0025] As used herein, the term "proximal" refers to a location on the device that is closest to the clinician using the device and farthest from the patient in connection with whom the device is used when the device is used in its normal operation (that is, to the right in Fig. 5). Conversely, the term "distal" refers to a location on the device that is farthest from the clinician using the device and closest to the patient in connection with whom the device is used when the device is used in its normal operation (that is, to the left in Fig. 5).

[0026] In accord with one aspect of the instant invention, a needle assembly 100 includes and an apparatus or shield 1 for shielding the tip of a curved needle, such as an epidural needle 50. Typically, epidural needles have a smooth exterior surface, that is, they are free from external features, other than the curved tip. Of course, the epidural needle may be of a variety of configurations and still practice aspects of the invention. For example, the needle may include a secondary bevel, such as disclosed in U.S. Patent 6,273,877, incorporated herein by reference. Further, the needle may be employed with a catheter, or as part of a catheter/needle assembly kit, such as disclosed in U.S. Patent 5,470,318, incorporated herein by reference. Further, the needle may be employed with other accessories, such as apparatus for regulating the length of a combined spinal-epidural needle, such as disclosed in U.S. Patents 5,480,389 and 5,836,914, each incorporated herein by reference. While the instant invention is currently intended for use with an epidural needle, it will be appreciated that aspects of the invention may be employed with any needle having a tip width that is larger than the diameter of the needle body, or a curve (or other structure) that results in a portion of the needle at or near the tip extending radially outward beyond the radial limit of the body of the needle. Such needles would include needles having a curved end and bifurcated needles. [0027] The needle 50 includes a body portion 51 that has a substantially cylindrical shape. A tip 52 is located at the distal end of the body portion. The needle is provided with a central cavity 150 that permits fluid flow through the needle. The tip portion of the needle is curved such that it extends radially beyond the exterior of the body portion, forming an offset 53 (see Fig. 1A). The width of the needle including the offset is referred to herein as the tip width 54. While the dimensions of the needle will vary depending upon the desired application, one exemplary needle has an overall useful length of 3.5 inches, with a diameter of 0.054 inches, and an offset of 0.010 inches.

[0028] The apparatus or shield 1 for shielding the needle 50 includes a cap or housing 10 that is slidingly mounted to the body portion 51 of the needle at the proximal end of the needle (see Fig. 2). As discussed more fully below, after the needle is used, the caregiver may slide the cap distally along the needle. As the cap slides over the tip portion 52, the tip portion is captured within the cap (see Fig. 3). The cap engages the tip portion, preventing further sliding movement in either a distal or a proximal direction. Alternatively, or additionally, a tether may connect the cap 10 to the needle hub 70, thereby restricting distal movement of the cap with respect to the needle (see Fig. 3A). Preferably, the cap includes finger grips 16 formed on the side ends 15 of the cap to direct the placement of the caregiver' s fingers and to provide a more assured grip. The side ends, bottom 14, top 13, front plate 24 and yoke 20 of the cap prevent access to the mechanisms in the cap that hold the tip in place. [0029] The cap 10 includes a yoke 20 disposed at the proximal end 11 of the cap.

In accord with one aspect of the invention, the yoke is a cylindrical ring with a central opening 32. A rigid sleeve 21 is attached to the distal end of the yoke and extends toward the distal end 12 of the cap. A channel 22 is disposed within the sleeve. Preferably, the channel has a cylindrical shape and extends along an axis 31. The sleeve forms a proximal collar 28 with a proximal opening 26, and a distal collar 29 with a distal opening 27. As shown in Fig. 9, for example, the proximal collar and the distal collar are integrally formed with the sleeve but other arrangements may be employed and still practice aspects of the invention. For example, as seen in Fig. 11, the distal collar and the proximal collar can be distinct structures, separated by a selected distance. As discussed below, the diameter of the channel (whether the channel is defined by integral or distinct collars) is slightly larger than the outer diameter of the body portion of the needle. This close tolerance prevents the needle from bending significantly as the curved tip contacts the proximal collar. As the length of the sleeve increases (or the distance between the proximal collar and the distal collar increases), there is less need for a close fit between the channel and the body portion of the needle. [0030] An arm 23 is attached to the distal end of the sleeve 21 (or distal collar 29) at the bottom. The arm extends toward the distal end 12 of the cap 10. A front plate 24 is attached to the arm at its distal end. An aperture 25 is disposed in the front plate and is aligned with the axis 31 of the sleeve. The aperture extends completely through the front plate, forming a passageway for the needle 50, including the tip 52. In accord with one aspect of the invention, the cap, including the front plate, the arm, the sleeve, the side ends and the yoke are integrally formed from a rigid plastic material, such as polypropylene, polystyrene, acrylic, polycarbonate or the like.

[0031] Means are provided for preventing distal movement of the tip portion 52 after it is captured within the cap 10. In accord with one aspect of the invention, a clip, such as a leaf spring 40, is mounted to the sleeve 21 by a pin 30. The leaf spring extends distally from the pin toward the front plate 24. A tab 41 is attached to the distal end of the leaf spring. A hook 42 is attached to the tab, remote from the leaf spring. In accord with one aspect of the invention, the leaf spring, tab and hook are stamped from a single piece of metal, such as stainless steel. As discussed more fully below, the leaf spring is movable from a first, biased position (see Fig. 6) in which the hook engages the needle 50, preventing the leaf spring from actuating, to a second, unbiased position (see Fig. 9) in which the needle is moved out of engagement with the hook and the leaf spring is actuated. [0032] Referring specifically to Figs. 6 and 9, it will be appreciated that the clip 40 is contained within the footprint of the side ends 15 of the cap 10, whether the clip is in the actuated condition or the unactuated condition. Specifically, the clip is sized in view of the side ends such that no portion of the clip extends beyond the cap. This arrangement reduces the likelihood of inadvertent interference with the clip and the shield. Further, the sleeve 21 (or proximal collar 28 and distal collar 29) is contained within the footprint of the side ends, reducing the ability to interfere with the operation of the shield. [0033] The proximal end of the needle body 51 is secured to a needle hub 70.

Specifically, the needle body is inserted into a mounting post 73 and secured in place by gluing or insert molding. A luer lock 71 or other connector is located at the proximal end of the needle hub. Finger guards 72 extend radially outward from the needle hub. A mounting post 73 is positioned at the distal end of the needle hub, surrounding the needle. The post provides additional area of interface between the needle and the needle hub to ensure that the needle is securely maintained on the hub. Locking fingers 74 are mounted to the distal end of the needle hub, disposed near to the mounting post. Preferably, the needle hub, luer lock, mounting post and finger guards are integrally formed from a rigid plastic material such as polypropylene, polystyrene, acrylic, polycarbonate or the like. It will be appreciated that the needle hub could be assembled from distinct parts and different materials and still practice aspects of the invention.

[0034] A flexible, solid rod 80 is provided having a rod hub 82 attached at its proximal end. Before use, the rod is disposed within the central cavity 150 such that the proximal end 81 of the rod is relatively flush with the distal opening of the needle 50. A tab 84 on the rod hub is slidingly engaged within a slot 75 in the needle hub. The rod hub is positioned such that the tab is disposed in the slot it can be readily grasped by the practitioner to remove the rod from the needle during use.

[0035] A safety cover 90 is provided having a proximal end 92 and a distal end 91.

Ribs 94 are mounted to the wall 95 of the cover at the proximal end and extend radially within the cover. A seat 96 is provided along the ribs to selectively mate with the fingers 74, as discussed more fully below. [0036] To use the shield 1 of the instant invention, the proximal portion of the body

51 of the needle 50 is threaded through the aperture 25 in the front plate 24. The leaf spring 40 is displaced from the unbiased position so that the tab 41 is no longer aligned with the aperture and the channel 26. Alternatively, the leaf spring may be mounted to the sleeve 21 by the pin 30 after the needle is inserted into the cap 10. Once in place, the hook 42 engages the needle, preventing the leaf spring from actuating and thereby preventing the tab from being moved to a position aligned with the sleeve and aperture. The cap is then slid along the length of the needle to the proximal end of the needle for use by the caregiver. [0037] As the shield 1 is moved proximally, the mounting post is seated within the opening 32. Optionally, the mounting post fits snugly within the opening such that there is some frictional interference between the post and the surface forming the opening. In the proximal position, the yoke 20 is disposed between the fingers 74 and the mounting post. The yoke forces the fingers outward such that the fingers engage the seat 96 of the ribs 94 of the cover 90. Consequently, the cover is held in place on the fingers until removed by the caregiver. As depicted in the drawings, the fingers are flanged outward at the point remote from the finger guards 72. This flanged portion 174 is displaced into engagement with the cover. It will be appreciated that other arrangements could be employed and still practice aspects of the invention. For example, the cover could be provided with an internal rib that mates directly with the finger guard or needle hub. Further, the shield could be provide with a rib that selectively mates with the mounting post 73, thereby maintaining the shield in place until actuated by the caregiver.

[0038] In use, the caregiver removes the safety cover 90 by pulling it off the distal end of the needle. The caregiver then inserts the needle in a traditional fashion. Due to the location of the cap 10 at the proximal end of the needle 50 there is minimal change in the performance or "feel" of the needle. Further, no additional "feature" on the needle (beyond the traditional structure of such needles) is required which might modify the performance of the needle as it passes through the human tissue. [0039] After insertion, the caregiver removes the rod 80, attaches a fluid line (such as a syringe or drip chamber) to the luer lock 75 and delivers anesthesia through the central cavity 150. After delivery of the anesthesia, the caregiver removes the needle from the patient, grips the finger grips 16 and slides the cap 10 distally, toward the tip 52 of the needle 50. As the shield is displaced axially, it is pulled out of engagement with the fingers. The aperture 25 is sized to allow passage of the body 51 of the needle as well as the tip 52 of the needle. Specifically, the aperture is large enough to accommodate the offset 53 at the tip. As the tip of the needle moves toward the distal end 12 of the cap, it engages the distal opening in the sleeve 21 (or in the distal collar 29) (see Fig. 9). The distal opening is sized to permit passage of the body of the needle but to prevent passage of the tip. Specifically, the distal opening is sized to be smaller than the tip width 54. Preferably, the distal opening is sized to be just slightly larger than the body portion of the needle. Since the needle is within the sleeve, it cannot pivot to allow the tip through the distal opening. Further, the shield prevents removal of the needle despite rotation of the needle within the shield. Consequently, the tip cannot pass through the sleeve and the cap cannot be pulled off the needle in a distal direction. [0040] As the tip 52 is moved proximally within the cap 10, it passes the hook 42. Consequently, the hook is no longer engaged to the needle (see Fig. 9). The leaf spring therefore actuates, returning to its unbiased position, lying substantially flat against the exterior of the sleeve. The tab is then displaced toward the bottom 14 of the cap such that it is aligned with the channel 26 and the aperture 25. Should the needle be moved distally within the cap, the needle tip would engage the tab, preventing the tip from passing back through the aperture. The hook 42 is designed to trap the tip should the tab be deformed by force.

[0041] In accord with another aspect of the invention, a tether 200 is provided, attaching the needle hub 70 to the shield body 10. The tether is provided with a length, in view of the curvature of the needle, that allows the shield to be moved along the needle 50 until the tip passes the hook 42 (thereby actuating the spring 41). However, the tether prevents the removal of the shield from the tip. When such a tether is used, the sleeve is not required to be used to prevent the removal of the shield from the needle. Consequently, the sleeve may be designed to achieve ease of manufacture. Of course, a tether may be employed in conjunction with a sleeve to restrict movement of the shield off the needle tip. [0042] It will be appreciated that other structures may be employed to prevent the tip of the needle from passing back out through the aperture. For example, other structures are disclosed in U.S. Patent 6,004,294 and U.S. Patent Application 09/717,148 (filed November 21, 2000), both incorporated herein by reference, which may be employed advantageously with the structure disclosed herein and still practice aspects of the instant invention.

Claims

I claim:

1. An apparatus for capturing the tip of an epidural needle, which needle includes a substantially cylindrical body and a curved tip, the apparatus including: a cap having a distal end and a proximal end, a top and a bottom, and two side ends, wherein the side ends provide a gripping surface for a user's fingers; a yoke disposed on the proximal end of the cap; a rigid sleeve attached to the yoke and extending in a distal direction from the yoke, wherein a channel is disposed in the sleeve, the channel having an axis; an arm attached to the distal portion of the sleeve and extending in the distal direction from the sleeve; a front plate attached to the arm remote from the sleeve and disposed at the proximal end of the cap, wherein an aperture is disposed in the front plate along the axis of the channel; wherein the aperture is sized to permit passage of the body of the needle and the tip of the needle there through; wherein the sleeve is sized to permit passage of the body of the needle but to prevent passage of the tip of the needle.

2. The apparatus of claim 1 further comprising a spring within the cap that extends into the channel when the spring is in an unbiased condition.

3. The apparatus of claim 2 wherein the spring is a leaf spring mounted to the sleeve and extending in a distal direction, and further comprising a tab that extends through the axis of the channel when the leaf spring is in an unbiased condition.

4. The apparatus of claim 2 further comprising a hook mounted to an end of the tab.

5. The apparatus of claim 2 wherein the leaf spring is contained within the footprint of side ends of the cap.

6. An epidural needle assembly comprising: an epidural needle having a proximal end and a distal end; a needle tip disposed at the distal end of the epidural needle, wherein the needle tip is curved to form an offset; a needle hub attached to the epidural needle at the proximal end; a cap having a proximal end and a distal end, slidingly mounted to the needle, and selectively engaged to the needle hub; a sleeve fixedly positioned within the cap, wherein a channel extends through the sleeve from a proximal end to a distal end, and wherein a proximal opening is located at the proximal end of the sleeve; wherein the sleeve opening is sized to permit passage of the body portion of the needle there through but to prevent passage of the tip portion.

7. The apparatus of claim 6 wherein the epidural needle defines a central cavity and further comprising a flexible rod removably disposed within the central cavity.

8. The apparatus of claim 6 wherein the needle hub comprises a mounting post selectively engaged to the cap.

9. The apparatus of claim 8 wherein the mounting post is frictionally engaged to the cap.

10. The apparatus of claim 6 further comprising a means to selectively engage the cap's exterior to the needle hub.

11. The apparatus of claim 6 further comprising fingers mounted to the needle hub near the mounting post such that, when the cap is disposed proximally on the needle, the fingers engage the cap.

12. The apparatus of claim 11 wherein the fingers include a flanged portion remote from the needle hub that engages the needle hub.

13. The apparatus of claim 12 further comprising a cover selectively engaged to the fingers.

14. The apparatus of claim 13 wherein, when the cover is engaged to the fingers, the fingers are biased inward into engagement with the cap.

15. The apparatus of claim 14 wherein the cover includes a rib with a seat wherein, when the cover is engaged to the fingers, the flanged portion of the fingers is disposed in the seat.

16. The apparatus of claim of claim 6 further comprising a front plate secured to the distal end of the cap and means for preventing the needle tip passing through the front plate.

17. The assembly of claim 6 further comprising a tether attached to the cap and the needle hub.

18. The apparatus of claim 6 further comprising: a mounting post on the needle hub attached to the epidural needle; fingers mounted to the needle hub near the mounting post such that, when the cap is disposed proximally on the needle, the fingers engage the cap, wherein the fingers include a flanged portion remote from the needle hub that engages the needle hub; a cover selectively engaged to the fingers and including a rib with a seat wherein, when the cover is engaged to the fingers, the flanged portion of the fingers is disposed in the seat; and a clip mounted within the cap for preventing the needle tip passing through the distal end of the cap.

19. An needle assembly comprising: a needle having a proximal end and a distal end, with a body portion near the proximal end and an offset near the distal end; a cap having a proximal end and a distal end, the cap being movable along the needle from a proximal position to a distal position; a proximal collar fixedly mounted to the cap at a proximal location; a distal collar, separate from the proximal collar, fixedly mounted to the cap at a distal location; wherein the proximal collar and the distal collar are separated by a selected distance such that the offset is prevented from passing through the proximal collar.

20. An apparatus for capturing the tip of a needle, which needle includes a substantially cylindrical body and a curved tip defining an offset, the apparatus including: a cap having a distal end and a proximal end, a top and a bottom, and two side ends, wherein the side ends define a footprint; a proximal collar fixedly mounted to the cap at a proximal location; a distal collar fixedly mounted to the cap at a distal location; wherein the proximal collar and the distal collar define a channel and are separated by a selected distance such that the offset is prevented from passing through the proximal collar; a clip disposed within the cap and movable from an unactuated condition in which the clip is outside of the channel to an actuated condition in which the clip is disposed in the channel; wherein the clip is disposed within the footprint in both the actuated and unactuated conditions.