WO2005060679A2

WO2005060679A2 - Safety shield for medical needles

Info

Publication number: WO2005060679A2
Application number: PCT/US2004/042560
Authority: WO
Inventors: Mark F. Ferguson; Donald Solomon; Roy Barrus; Jeremy Snow
Original assignee: Specialized Health Products, Inc.
Priority date: 2003-12-18
Filing date: 2004-12-17
Publication date: 2005-07-07
Also published as: WO2005060679A3

Abstract

A medical needle shield apparatus (46) is provided that includes a needle hub (101) having a needle cannula (43) extending therefrom. At least one shield is extensible from a retracted position to an extended position to enclose a distal end of the needle. The shield includes a binding member (47) disposed within the shield and defines binding surfaces that form an aperture configured for slidable receipt of the inner needle. The binding member includes at least one drag inducing member (64) that engages the inner needle during slidable receipt to create a drag force. The drag force facilitates inclination of the binding member such that the binding surfaces engage the inner needle to prevent slidable movement. The shield includes at least one retention element engageable between the shield and the needle hub.

Description

SAFETY SHIELD FOR MEDICAL NEEDLES BACKGROUND 1. Technical Field The present disclosure generally relates to safety shields for medical needles, and more particularly, to safety shields that protect a needle point of a medical needle. 2. Description of the Related Art Problems associated with inadvertent needle sticks are well known in the art of blood sampling, percutaneous medication injection and other medical procedures involving use of medical needles. Significant attention has been focused on needle stick problems due to the contemporary sensitivity of exposure to AIDS, Hepatitis and other serious blood-borne pathogen exposures. Procedures for removing a needle from a patient commonly require a technician to use one hand to place pressure at the wound site where the needle is being withdrawn, while removing the needle device with the other hand. It is also common practice for an attending technician to give higher priority to care for the patient than is given to disposal of a needle. In the case of typical needle devices without safety shields, such priority either requires the convenience of an available sharps container within reach or another means for safe disposal without leaving the patient's side. Providing adequate care while following safety procedures is often compounded by the patient's physical condition and mental state, such as in burn units and psychiatric wards. Under such conditions, it is difficult to properly dispose of a used needle while caring for a patient. The widespread knowledge and history associated with needle care and disposal problems have resulted in numerous devices for preventing accidental needle sticks. Problems of current safety devices include difficulty of use and high cost due to their complexity and number of parts. Other known devices employ sheaths that are spring activated, telescoping, pivoting, etc. These devices, however, may disadvantageously misfire or be cumbersome to activate. Further drawbacks of current devices include high manufacturing costs due to complexity and the number of parts. Thus, these types of prior art devices may not adequately and reliably shield medical needle apparatuses to prevent hazardous exposure. It is desirable during certain medical procedures to retain a safety shield to a needle hub. It is also desirable to prevent a needle safety shield from becoming dislodged during handling and preparation for use. For example, it is important to prevent a needle safety shield from disengaging a needle hub during removal of a sheath from certain types of medical needle devices. Consequently, there remains a need to provide a more satisfactory solution for needle safety devices by overcoming the disadvantages and drawbacks of the prior art. Therefore, it would be desirable to provide a more adequate and reliable medical needle shield apparatus that employs a safety shield slideably movable along a medical needle to prevent hazardous exposure to a needle tip. Such a needle shield apparatus should be easily and reliably movable to shield a needle tip of a needle cannula. Further, it would be desirable to provide a needle shield apparatus that allows adequate viewing of fluid flashback.

SUMMARY Accordingly, the present disclosure addresses a need for a medical needle shield apparatus which effectively and inexpensively protects a tip of a medical needle after use. The present disclosure resolves related disadvantages and drawbacks experienced in the art. More specifically, the apparatus and method of this invention constitute an important advance in the art of safety needle devices. hi one particular embodiment, a medical needle shield apparatus is provided in accordance with the principles of the present disclosure. The medical needle shield apparatus includes a needle hub having an outer needle cannula extending therefrom to a distal end. An inner needle is disposed for slidable movement with the outer needle cannula. At least one shield is extensible from a retracted position to an extended position to enclose a distal end of the inner needle. The shield includes a binding member disposed within the shield and defines binding surfaces that form an aperture configured for slidable receipt of the inner needle between the retracted position and the extended position. The binding member includes at least one drag inducing member such that the member engages the inner needle during slidable receipt of the inner needle to create a drag force with the inner needle. The drag force facilitates inclination of the binding member relative to a longitudinal axis of the inner needle such that the binding surfaces engage the inner needle to prevent slidable movement of the inner needle in the extended position of the shield. The binding member further includes a retainer extending therefrom such that the retainer is engageable with the inner needle to prevent inclination of the binding member prior to the extended position. The binding member may be inclinable, relative to a longitudinal axis of the inner needle, between a non-binding orientation whereby the inner needle is slidable relative to the binding member and a binding orientation whereby the binding surfaces engage the inner needle to prevent slidable movement of the inner needle in the extended position of the at least one shield. The binding member may include one or more outwardly arcuate arms that extend to the needle-communicating surface. The inner needle can be attached to a handle for manipulation thereof. The needle hub may define a hub slot configured for receipt of a retention element. The needle hub may be releasably mountable with a housing of the at least one shield. The medical needle shield apparatus may further include a plurality of shields. The at least one drag inducing member may define a cavity that is substantially aligned with the aperture. The cavity is configured for slidable receipt of the needle to create the drag force with the needle. The binding member may include a substantially planar aperture plate that includes the binding surfaces that form the aperture. The at least one drag inducing member may include a pair of arms extending from the aperture plate. The arms can have curled end portions spaced apart from the aperture plate. The arms can include deflectable members. The shield can include a housing that defines at least one blocking member extending from an interior surface thereof. The at least one blocking member can be engageable with the binding member for urging the binding member to a binding orientation. The aperture plate is axially movable for engagement with the at least one blocking member that causes inclination of the binding member to a binding orientation. The medical needle shield apparatus may further include an outer housing that encloses the at least one shield. The outer housing supports the at least one shield for relative rotational movement therewith. The at least one shield can be supported for relative rotational movement by the outer housing by at least one bearing. In the medical needle shield apparatus of this embodiment the shield also includes a sheath retention element extending therefrom. The sheath retention element has a releasable fit with a sheath such that disengagement of the sheath with the sheath retention element does not disengage the retention element engaged between the shield and the hub. The sheath retention element can be configured for press fit, snap fit or threaded fit with the sheath, for example. A hub retention element is formed with the shield and configured for releasable engagement with a shield retention element formed with the needle hub.

The shield includes a binding member disposed within the shield. The binding member defines binding surfaces that form an aperture configured for slidable receipt of the outer needle cannula between the retracted position and the extended position. The binding member includes at least one drag inducing member which engages the outer needle cannula during slidable receipt of the outer needle cannula to create a drag force with the outer needle cannula. The drag force facilitates inclination of the binding member relative to a longitudinal axis of the outer needle cannula such that the binding surfaces engage the outer needle cannula to prevent slidable movement of the outer needle cannula in the extended position of the shield. The binding member further includes a retainer exitending therefrom such that the retainer is engageable with the outer needle cannula to prevent inclination of the binding member. In yet another embodiment, the present disclosure provides a medical needle shield apparatus including a needle hub and a needle disposed with the hub. The needle hub includes a magnifier section configured for viewing fluid flashback exiting the needle. At least one shield is extensible from a retracted position to an extended position to enclose a distal end of the needle. A binding member is disposed within the shield and defines binding surfaces that form an aperture configured for slidable receipt of the inner needle between the retracted position and the extended position. In this embodiment, the magnifier includes a curved section defining a viewing area that refracts light from a smaller focal area for magnified viewing thereof. The medical needle shield apparatus according to this embodiment can be configured for use with particular hubs known in the art such as, for example, one- wall introducer needle hubs, biopsy needle hubs, spinal hubs or epidural hubs. The medical needle shield as described herein can be adapted for use with a

Seldinger Needle, One- Wall Introducer Needle, Cournand Needle, Biopsy Needle, Introducer Needle, Bone Biopsy Needle, Huber Needle, Spinal Needle, Epidural Needle, Fine Aspiration needle, or Co-axial Needle and the like. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other features and advantages of the present invention will be more fully understood from the following detailed description of the exemplary embodiments, taken in conjunction with the accompanying drawings in which: FIGURE 1 is a perspective view of one particular embodiment of a medical needle shield apparatus in accordance with the principles of the present disclosure; FIGURE 2 is a perspective view of a needle device for insertion through the needle device shown in FIGURE 1 ; FIGURE 3 is a perspective view of the needle device shown in FIGURE 2 inserted into the needle device shown in FIGURE 1; FIGURE 4 is a cross-sectional perspective view of the medical shield apparatus as shown in FIGURE 3; FIGURE 5 is an enlarged cutaway perspective view of the medical shield apparatus as shown in FIGURE 3; FIGURE 6 is a perspective view of the needle device shown in FIGURE 3 with the shield apparatus in the extended position; FIGURE 7 is a cross-sectional perspective view of the medical shield apparatus as shown in FIGURE 6; FIGURE 8 is an enlarged cutaway perspective view of the medical shield apparatus as shown in FIGURE 7; FIGURE 9 is a perspective view of an alternative embodiment of the medical needle shield apparatus according to the present disclosure; FIGURE 10 is an enlarged perspective view of the alternative embodiment of the medical shield apparatus as shown in FIGURE 9; FIGURE 11 is an enlarged cutaway perspective view of the alternative embodiment of the medical shield apparatus as shown in FIGURE 9; FIGURE 12 is an enlarged perspective view of the alternative embodiment of the medical shield apparatus as shown in FIGURE 9 showing engagement between a safety shield retention element and a hub retention element; FIGURE 13 is an enlarged perspective view of the alternative embodiment of the medical shield apparatus as shown in FIGURE 9 showing partial disengagement between a safety shield retention element and a hub retention element; FIGURE 14 is an enlarged perspective view of the alternative embodiment of the medical shield apparatus as shown in FIGURE 9 showing partial disengagement between a safety shield retention element and a hub retention element; FIGURE 15 is an enlarged perspective view of the alternative embodiment of the medical shield apparatus as shown in FIGURE 9 showing disengagement between a safety shield retention element and a hub retention element; FIGURE 16 is a perspective view of the alternative embodiment of the medical shield apparatus as shown in FIGURE 9 showing an extended needle shield; FIGURE 17 is a perspective view of an alternative embodiment of a medical shield apparatus similar to the embodiment shown in FIGURE 9 showing an extended needle shield; FIGURE 18 is a perspective view of an alternative embodiment of the medical needle shield apparatus according to the present disclosure; FIGURE 19 is an enlarged cutaway perspective view of the alternative embodiment of the medical shield apparatus as shown in FIGURE 18; FIGURE 20 is a perspective view of an alternative embodiment of the medical needle shield apparatus according to the present disclosure; FIGURE 21 is an enlarged perspective view of an alternative embodiment of a medical shield apparatus similar to the embodiment shown in FIGURE 9 showing a sheath having a sheath retention element; FIGURE 22 is perspective view of an alternative embodiment of a medical shield apparatus shown in FIGURE 9 showing a sheath retention element; FIGURE 23 is an enlarged perspective view of an alternative embodiment of a medical shield apparatus shown in FIGURE 21 showing a sheath disengaged from a sheath retention element; FIGURE 24 is an enlarged perspective view of a hub of a medical shield apparatus having a magnifier section according to an alternative embodiment of the present invention; FIGURE 25 is a an enlarged cutaway perspective view of the hub according to the alternative embodiment of the medical needle shield apparatus shown in FIGURE 24; and FIGURE 26 is a cross-sectional view of the hub according to the alternative embodiment of the medical needle shield apparatus shown in FIGURE 24.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS The exemplary embodiments of the medical needle shield apparatus and methods of operation disclosed are discussed in terms of medical needles for infusion of intravenous fluids, medication infusion or fluid collection, guiding of other needles, e.g., biopsy, and more particularly, in terms of needle shield apparatus employed with a needle cannula that prevent hazardous exposure to the needle tip, including, for example, inadvertent needle sticks. It is envisioned that the present disclosure, however, finds application to a wide variety of cannula needles and devices for the infusion of preventive medications, medicaments, therapeutics, etc. to a subject, such as, for example, epidural needles, spinal needles, biopsy needles, chiba needles, potts cournand needles, coaxial introducer needles, Y-sites, etc. It is also envisioned that the present disclosure may be employed for collection of body fluids and/or tissues, including those collected during procedures relating to soft tissue biopsy, bone biopsy, phlebotomy, digestive, intestinal, urinary, veterinary, etc. It is contemplated that the medical needle shield apparatus may be utilized with other medical needle applications including, but not limited to, fluid infusion, fluid collection, catheters, catheter introducers, guide wire introducers, biopsy needle introducers, spinal and epidural, biopsy, aphaeresis, dialysis, blood donor, Neress needles, Huber needles, etc. In the discussion that follows, the term "proximal" refers to a portion of a structure that is closer to a clinician, and the term "distal" refers to a portion that is further from the clinician. As used herein, the term "subject" refers to a patient that receives infusions or has blood, fluid and/or tissue collected therefrom using the medical needle shield apparatus. According to the present disclosure, the term "clinician" refers to an individual administering an infusion, performing fluid or tissue collection, installing or removing a needle cannula from a medical needle shield apparatus and may include support personnel. The following discussion includes a description of the medical needle shield apparatus, followed by a description of the method of operating the medical needle shield apparatus in accordance with the present disclosure. Reference will now be made in detail to the exemplary embodiments of the disclosure, which are illustrated in the accompanying figures. Turning now to the figures, wherein like components are designated by like reference numerals throughout the several views. Referring initially to FIGURES 1- 8, there is illustrated a medical needle shield apparatus, constructed in accordance with at least one embodiment of the principals of the present disclosure. The medical needle shield apparatus includes a shield 46 that is extensible from a retracted position (FIGURES 1 and 3) to an extended position (FIGURE 6) to enclose a distal end 50 of inner needle 51. In the retracted position, shield 46 is disposed adjacent to a needle hub 45 of outer needle 43. Although inner needle 51 in FIGURES 1-8 is shown as an epidural needle point, it is envisioned that shield 46 may be used with any needle tip. hi the illustrative embodiment, the needle assembly includes a hollow outer needle 43. Inner needle 51 is slideably and concentrically disposed with outer needle 43 for employment therewith during a medical needle application, as will be discussed. A handle 52 is comiected to inner needle 51 to facilitate manipulation thereof. Other needle assemblies are also contemplated, including for example, needle cannulae, guide wire/introducers, etc. A binding member 47 is disposed within shield 46 and defines binding surfaces 60. Binding surfaces 60 form an aperture 62 configured for slidable receipt of inner needle 51 and outer needle 43 between the retracted position and the extended position of shield 46. Binding member 47 includes a drag inducing member, such as, for example, friction members 64 extending therefrom. Binding member 47 has a retainer 57 that is engageable with outer needle 43 and inner needle 51 to prevent inclination of binding member 47. Friction members 62 are configured for slidable engagement with outer needle

43 and inner needle 51 between the retracted position and the extended position such that friction members 62 engage inner needle 51 to create a drag force with outer needle 43. It is envisioned that one or a plurality of friction members 62 may be employed. The drag force in conjunction with one of blocking members 48 and/or 55, cause binding member 47 to move to a binding position (FIGURES 7 and 8). The force created by blocking members 48 and/or 55 acts in a direction opposite to the drag force. This causes a force couple, which moves binding member 47 to the binding position. As inner needle 51 is released from engagement with retainer 57, binding member 47 moves to the binding position. Inclination of binding member 47 is no longer opposed by engagement with inner needle 51 at retainer 57. Thus, binding member 47 is subject to inclination into the binding position. Inclination of binding member 47 causes binding surfaces 60 to frictionally engage inner needle 51 to prevent movement thereof. Blocking members 48 and/or 55 cause binding member 47 to move to the binding position as forces imposed on shield 46 cause relative movement thereof in either direction along longitudinal axis x. This maintains inner needle 51 within shield 46 to avoid hazardous exposure to distal end 51. It is envisioned that retainer 57 may include ribs, projections, cavities, etc. for engagement with inner needle 51 or that a portion of retainer 57 engages inner needle 51. Shield 46 includes a housing 66 that encloses binding member 47. In the illustrative embodiment, housing 66 may comprise two separate sections. It is envisioned that the housing sections may be variously configured and dimensioned such as, for example, rectangular, spherical, etc. It is further envisioned that the housing sections may be joined by any appropriate process such as, for example, snap fit, adhesive, solvent weld, thermal weld, ultrasonic weld, screw, rivet, etc. Alternatively, housing 66 may be monolithically formed or integrally assembled of multiple housing sections and may be substantially transparent, opaque, etc. Housing 66 may include ribs, ridges, etc. to facilitate manipulation of the medical needle shield apparatus. It is contemplated that binding surfaces 60 may include sharp edges to increase frictional engagement. It is further contemplated that the binding friction force may be created and varied by one or more altering factors, such as, for example, aperture 62 configuration and dimension, inner needle 51 configuration and dimension, binding member 47 thickness, the dimension from blocking members 48, 55 contact point to the centerline of inner needle 51, and the coefficient of friction between aperture 62 and inner needle 51 depending on the particular requirements of a needle application. It is envisioned that friction members 64 may be configured so as to vary the drag force with variation of the inclination of the binding member 47, this variation in drag force may be accomplished by geometric changes in the shape of the friction members 64, such as wedge shapes or the inclusion of notches to engage inner needle 51. This variation in drag force may also be accomplished through the selective application of friction modifying materials or coatings such as oils, jells, greases, or coatings which increase friction. In certain procedures an introducer needle, such as outer needle 43, is first inserted into the patient in order to provide access for a through-the-needle device, such as inner needle 51 having a smaller diameter which is placed within and concentric to the outer needle 43. The inner needle 51 is inserted through the outer needle 43 foπning a co-axial assembly 49. After the inner needle 51 is introduced through the outer needle 43 and the medical procedure is complete, the co-axial assembly 49 may be removed all together and intact from the patient as illustrated in FIGURE 3. In order to protect the shaip point 50 of inner needle 51 as part of the coaxial assembly, the safety shield 46 is extended from the retracted position adjacent to hub 45, beyond the point 44 of outer needle 43, and out to the sharp point 50 of inner needle 51. Since the inner needle 51 is through outer needle 43, the binding member 47 cannot pivot to lock to the point 44 of outer needle 43. Binding member 47 must continue to be advanced to the sharp point 50 of inner needle 51 where retainer 57 senses the end of the device (i.e., sharp point 50) and binding member 47 moves into a binding orientation on inner needle 51 as previously described. The outer needle point 44 is protected by the inner needle 51 that is through the bore of outer needle 43. Outer needle 43 remains floating on inner needle 51 and is captured between the handle 52 of inner needle 51 and shield 46, which is locked in the extended position to inner needle 51. If inner needle 51 is removed from outer needle 43 prior to the activation of shield 46, shield 46 may still be advanced to the end of outer needle 43 where it will sense point 44 of outer needle 43 and lock in place as previously described. Referring now to FIGURES 9 - 20, an embodiment of the medical needle shield apparatus according to the present disclosure includes means for releasably retaining the safety shield to the hub of a medical needle. As shown in FIGURES 9- 11, the hub 101 includes a safety shield retention element 102, which interacts with a hub retention element on the safety shield 104. This interaction retains the safety shield 104 to the hub 101 until intentionally removed. The interaction may include, for example, a bayonet fitting, ramp, detents (see e.g., FIGURE 6 showing detent 68 and corresponding slot 70 in hub 45), snaps deformable geometry, friction fitting suction, magnets or any suitable removable retention configurations kno i in the art. The safety shield may be released from the retention element 118 by overcoming the interaction method. One configuration shown in FIGURES 12 - 17 includes a bayonet fitting. This fitting is overcome, for example, by rotating the safety shield 104 and then extending the safety shield 104 distally. Other such fittings and interaction methods are similarly overcome. This configuration also provides a safety shield 104 with an external grip element 110. The external grip element may be used to facilitate actuation of the safety shield 104. The clinician may grasp the external grip element 110 and dislodge the retention element 118 (if necessary) and extend the safety shield 104 distally until the safety shield 104 is activated. A safety shield 104, based on a binding component as described herein, is adapted for use with external grip element 110. The external grip element can include, for example, wings, tabs, buttons, annular rims, and the like. Selected textures such as ribs, grips contours and the like may also be provided on the safety shield surface to aid griping. Referring now to FIGURES 18 - 20, depicted is another means for releasably retaining the safety shield to the hub of a medical needle. Safety shield 104 includes a safety shield retention element 118, which interacts with hub 101 via a friction fit at surface 105. This interaction retains the safety shield 104 to the hub 101 until intentionally removed. The interaction between retention element 118 and hub 101 may also serve as an alignment feature for safety shield 104 relative to the hub 101. The safety shield may be released from the retention element 118 by overcoming the friction fit at surface 105. It is envisioned that one or more retention elements 118 may be utilized. FIGURE 20 shows another embodiment of retention element 118 for releasably retaining the safety shield to the hub of a medical needle. Retention element 118 includes an extended surface, which interacts with hub 101 via a friction fit at surface 105. This interaction retains the safety shield 104 to the hub 101 until intentionally removed. The interaction between retention element 118 and hub 101 may also serve as an alignment feature for safety shield 104 relative to the hub 101. The safety shield may be released from the retention element 118 by overcoming the friction fit at surface 105. It is envisioned that one or more retention elements 118 may be utilized. A particular configuration shown in FIGURES 21 - 23 includes a sheath 120 fitting to safety shield 104 by means of a sheath retention element 121. The sheath retention element may be coupled with safety shield retention element 102 such that removal of the sheath 120 does not interfere or dislodge the safety shield 104. The sheath retention element 121 may include, for example, friction fit, press fit, suction, bayonet fitting, detents, deformable geometry, snaps and the like. The sheath retention element 121 retains sheath 120 until intentionally removed. To remove sheath 120 a clinician may grasp sheath 120 and urge sheath 120 distally until sheath retention element 121 is overcome. Referring to FIGURES 24 - 26, another particular embodiment of the medical safety shield apparatus according to the present disclosure includes a hub 201 having a magnifier section 202 for viewing fluid flashback therein. Hub 201 includes a magnifier section 202 formed or installed with the hub 201 for viewing fluid flashback directly after the flashback exits needle 203. Viewing area 204 of the magnifier section 202 as shown in FIGURE 25 is larger than a focal area 205 of the magnifier section 202. A clinician is thereby allowed to view a small section of flashback area 206 through a larger viewing area 204 to more easily view fluid flashback and thereby decrease response time to certain medical procedures. Magnifier section 202 on hub 201 enhances viewing of focal area 205 by refracting light from focal area 205 to the clinician's viewing area 204. FIGURE 26 illustrates refraction of light from focal area 205 through the magnifier section 202 as the light passes through curved section 207 of viewing area 204 from focal area 205. The focal area 205 is thereby magnified when viewed from viewing area 204 and visual detection of fluid flashback is thereby enhanced. The size and location of focal area 205 and the amount of magnification are dependent on the curvature of curved section 207. Focal area 205, curved section 207 and viewing area 204 can be adapted to better suit a specific application. For example, such adaptations include, but are not limited to, large and smaller focal areas 205, more or less magnification, and larger or smaller viewing areas 2O4. It is contemplated that magnifier section 202 can be constructed from any of a large number of transparent materials such as, for example, polycarbonate, polystyrene, acrylic, PNC, glass or the like. It is further contemplated that magnifier section 202 may be formed integrally with hub 201, for example, wherein hub 201 is constructed from a substantially transparent material. The invention of the present disclosure may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

WHAT IS CLAIMED IS: 1. A medical needle shield apparatus comprising: a needle hub; a needle disposed with said hub; at least one shield being extensible from a retracted position to an exitended position to enclose a distal end of said needle; a binding member disposed within said shield and comprising binding surfaces that define an aperture configured for slidable receipt of said needle between a retracted position and an extended position, the binding member comprising a retainer extending therefrom such that the retainer is engageable with the needle to prevent inclination of the binding member while the retainer is engaged with the needle, the binding member further comprising at least one drag inducing member configured to engage the needle and create a drag force with the needle to cause inclination of the binding member relative to a longitudinal axis of the needle once the retainer extends beyond the distal end of the needle such that the binding surfaces engage the needle to prevent slidable movement of the needle in the extended position of the shield; and at least one retention element engageable between said shield and said hub.

2. The medical needle shield apparatus according to claim 1, wherein said retention element comprises a hub retention element formed with said shield and configured for releasable engagement with a shield retention element formed with said hub.

3. The medical needle shield apparatus according to claim 1, wherein said at least one retention element comprises one of a bayonet fitting, ramp, detent, snap, deformable geometry, friction fitting, magnet couple or suction device.

4. The medical needle shield apparatus according to claim 1, wherein said shield comprises a sheath retention element extending therefrom having a releasable fit with a sheath such that disengagement of said sheath with said sheath retention element does not disengage said retention element engaged between said shield and said hub.

5. The medical needle shield apparatus according to claim 5, wherein said sheath retention element is configured for one of press fit, snap fit or threaded fit with said sheath.

6. A medical needle shield apparatus as recited in claim 1, wherein said binding member is inclinable relative to a longitudinal axis of said needle between a non-binding orientation whereby said needle is slidable relative to said binding member and a binding orientation whereby said binding surfaces engage said needle to prevent slidable movement of said needle in an extended position of said shield.

7. A medical needle shield apparatus as recited in claim 1, further comprising an outer housing that encloses said shield, said outer housing supporting said shield for relative rotational movement therewith.

8. A medical needle shield apparatus as recited in claim 7, wherein said shield is supported for relative rotational movement by said outer housing by at least one bearing.

9. A medical needle shield apparatus as recited in claim 1, wherein said needle is attached to a handle for manipulation thereof.

10. A medical needle shield apparatus as recited in claim 1, wherein said needle hub comprises a magnifier section configured for viewing fluid flashback exiting said needle.

11. The medical needle shield apparatus according to claim 10, wherein said magnifier comprises a curved section defining a viewing area, said curved section refracting light from a smaller focal area for magnified viewing of said focal area.

12. The medical needle shield apparatus according to claim 10, wherein said hub is one of a one-wall introducer needle hub, a biopsy needle hub, a spinal hub or an epidural hub.

13. A medical needle shield apparatus as recited in claim 1, wherein said needle shield is adapted for use with an inner needle inserted into said needle.

14. A medical needle shield apparatus as recited in claim 1, wherein said shield initially resides on the needle in the refracted position and then on the inner needle in the extended position.