(12) United States Patent
`Brimhall et al.
`
`USOO6379333B1
`(10) Patent No.:
`US 6,379,333 B1
`(45) Date of Patent:
`Apr. 30, 2002
`
`(54) CATHETER AND INTRODUCER NEEDLE
`ASSEMBLY WITH NEEDLE SHIELD
`
`(75) Inventors: Greg L. Brimhall, West Jordan;
`Stephen L. Thoresen, Orem; Weston
`F. Harding, Lehi; Glade H. Howell;
`Timothy J. Erskine, both of Sandy, all
`of UT (US)
`
`(73) Assignee: Becton, Dickinson and Company,
`Franklin Lakes, NJ (US)
`s
`Subject to any disclaimer, the term of this
`p
`is Sh used under 35
`
`(*) Notice:
`
`(21) Appl. No.: 09/312,335
`(22) Filed:
`May 14, 1999
`Related U.S. Application Data
`(63) Continuation-in-part of application No. 09/057,718, filed on
`Apr. 9, 1998, now Pat. No. 6,004,294.
`(51) Int. Cl. .......................... A61M 5/178; A61M 5/00
`(52) U.S. Cl. ................................... 604/164.11; 604/110
`(58) Field of Search ....................... 604/164.01, 16408,
`604/110, 192, 197, 198, 263,264, 164.11,
`523; 128/919
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`4,816,024 A 3/1989 Sitar et al. .................. 604/192
`4,832,696 A 5/1989 Luther et al. ............... 604/164
`4,846,811 A 7/1989 Vanderhoof................. 604/263
`4,964,854 A 10/1990 Luther ........................ 604/166
`5,049,136 A * 9/1991 Johnson
`5,085,648 A 2/1992 Purdy et al. ................ 604/198
`5,215.528 A 6/1993 Purdy et al. ................ 604/164
`RE34,416 E
`10/1993 Lemieux ..................... 604/164
`5,409,461 A 4/1995 Steinman .................... 604/110
`5,558,651. A 9/1996 Crawford et al. ........... 604/263
`5,601,536 A 2/1997 Crawford et al. ........... 604/263
`5,613,952 A
`3/1997 Pressly, Sr. et al. ........ 604/110
`C. A ... .." tal
`6,117,108 A * 9/2000 Woehr et al.
`
`OW e a
`
`2Y-- a---
`
`sk -
`
`cited by examiner
`
`Primary Examiner Michael J Hayes
`(74) Attorney, Agent, or Firm-Eric M. Lee
`(57)
`ABSTRACT
`A catheter and introducer needle assembly with needle
`Shield is provided wherein the needle includes an enlarged
`diameter portion and a distally facing shoulder. The needle
`Shield includes a means for engaging the distallv facin
`gaging
`y
`9.
`shoulder to prevent unwanted distal movement of the needle
`once the needle has been withdrawn into the needle shield.
`The needle shield also includes a Small diameter opening
`adjacent to its proximal portion to limit proximal movement
`of the needle out of the needle shield.
`
`4,810.248 A 3/1989 Masters et al. ............. 604/192
`
`3 Claims, 15 Drawing Sheets
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`B. Braun 2010
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`US. Patent
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`Apr. 30, 2002
`Apr. 30, 2002
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`US. Patent
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`Apr. 30, 2002
`Apr. 30, 2002
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`U.S. Patent
`US. Patent
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`A r. 30, 2002
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`US 6,379,333 B1
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`U.S. Patent
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`Apr. 30, 2002
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`Apr. 30, 2002
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`Sheet 10 of 15
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`Apr. 30, 200
`Apr. 30, 2002
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`Apr. 30, 2002
`Apr. 30, 2002
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`Sheet 15 Of 15
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`1
`CATHETER AND INTRODUCER NEEDLE
`ASSEMBLY WITH NEEDLE SHIELD
`
`This application is a continuation-in-part of application
`Ser. No. 09/057,718, filed Apr. 9, 1998, now U.S. Pat. No.
`6,004,294.
`
`BACKGROUND OF THE INVENTION
`The Subject invention relates to a catheter and introducer
`needle assembly that includes a needle shield that will safely
`shield the sharp distal tip of the introducer needle after the
`needle has been used to insert the catheter into a patient.
`Catheters, particularly intravenous (IV) catheters, are
`used for infusing fluid, Such as normal Saline Solution,
`various medicaments and total parenteral nutrition, into a
`patient or withdrawing blood from a patient. Peripheral IV
`catheters tend to be relatively short, and typically are on the
`order of about two inches or less in length. The most
`common type of IV catheter is an over the needle peripheral
`IV catheter. AS its name implies, an over the needle catheter
`is mounted over an introducer needle having a Sharp distal
`tip. The catheter and the introducer needle are assembled So
`that the distal tip of the introducer needle extends beyond the
`distal tip of the catheter with the bevel of the needle facing
`up away from the patient's skin.
`The catheter and introducer needle assembly is inserted at
`a shallow angle through the patient's skin into a peripheral
`blood vessel, i.e. a Smaller blood vessel that is not connected
`directly to the heart but is one of the branches of the central
`blood vessels that is directly connected to the heart. In one
`technique, the introducer needle and catheter are inserted
`completely into the blood vessel together. In another
`technique, the introducer needle is partially withdrawn into
`the catheter after the initial Venipuncture. The catheter is
`then inserted completely into the blood vessel. In order to
`Verify proper placement of the assembly in the blood vessel,
`the clinician confirms that there is flashback of blood in the
`needle and in a flashback chamber located at the proximal
`end of the needle and which is typically formed as part of the
`needle hub. Once proper placement is confirmed, the clini
`cian applies preSSure to the blood vessel by pressing down
`on the patient's skin over the distal tip of the introducer
`needle and the catheter. This finger pressure occludes further
`blood flow through the introducer needle. The clinician
`withdraws the introducer needle, leaving the catheter in
`place, and attaches a fluid delivery device, a PRN or a
`deadender cap to the catheter hub. Once the introducer
`needle is withdrawn from the catheter, it is a “blood con
`taminated 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' must be
`immediately disposed. This concern has arisen 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 AIDS infected person must
`be avoided. AS noted above, if an introducer needle has been
`used to place a catheter in the vein of an AIDS infected
`perSon, the introducer needle is a vehicle for the transmis
`Sion of the disease. Although clinicians are aware of the need
`to properly handle “blood contaminated Sharps’, unfortu
`nately in certain medical environments, Such as emergency
`Situations or as a result of inattention or neglect, needlestickS
`with a contaminated introducer needle Still occur.
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`2
`AS a result of the problem of accidental needlesticks by
`“blood contaminated sharps’, various needle shields have
`been developed. Generally, such needle shields work for
`their intended purpose but could be improved. For example,
`Some needle Shields are bulky, difficult to use or require
`Special features or techniques to be operative.
`SUMMARY OF THE INVENTION
`It is therefore an object of this invention to provide a
`needle Shield that is compact.
`It is another object of this invention to provide a needle
`Shield that is simple and easy to use.
`It is still another object of this invention to provide a
`needle shield that requires no special features or technique
`to be operative.
`The catheter and introducer needle assembly with needle
`Shield of this invention includes a catheter having a distal
`end and a proximal end connected to the distal end of a
`catheter hub. The introducer needle has a Sharp distal tip and
`a proximal end connected to the distal end of a needle hub.
`A flashback chamber is defined in the needle hub. Typically
`a porous plug is located in the open proximal end of the
`flashback chamber to allow air to escape from the flashback
`chamber when blood enters the flashback chamber from the
`introducer needle. The catheter is coaxially disposed over
`the introducer needle So the Sharp distal tip of the introducer
`needle is distal of the distal end of the catheter. The
`introducer needle also defines, along a distal portion thereof,
`an enlarged diameter portion with a distally facing shoulder
`immediately distal thereof and a tapered portion immedi
`ately proximal thereof. The enlarged diameter portion coop
`erates with a needle Shield to prevent unwanted proximal
`movement of the introducer needle with respect to the
`needle shield once the introducer needle has been withdrawn
`into the needle shield after use. The distally facing shoulder
`cooperates with the needle Shield to prevent unwanted distal
`movement of the introducer needle once the introducer
`needle has been withdrawn proximally into the needle shield
`after use.
`The needle shield includes a main body portion defining
`a longitudinally extending passage through which the intro
`ducer needle extends. The needle Shield also includes a
`means for engaging the distally facing shoulder of the
`introducer needle to prevent distal movement of the intro
`ducer needle once the introducer needle has been proximally
`withdrawn into the needle shield. The longitudinally extend
`ing passage has a proximal portion that has a diameter
`sufficient to allow the proximal portion of the introducer
`needle to extend therethrough but that is too small to allow
`the enlarged diameter portion of the introducer needle from
`passing therethrough.
`The means for engaging the distally facing shoulder of the
`introducer needle can take many forms. For example, a
`Spring gate can be located in a hollow cavity portion of the
`main body portion of the needle Shield and about a portion
`of the introducer needle. The Spring gate has a generally U
`shaped configuration with a pair of tines that allow the
`introducer needle to pass between the tines. A biasing
`mechanism forces the Spring gate up into contact with the
`introducer needle. When the introducer needle is withdrawn
`proximally into the needle Shield, the introducer needle rides
`past the tines. When the enlarged diameter portion passes by
`the tines, the Spring gate is forced downwardly against the
`bias of the biasing mechanism to allow the enlarged diam
`eter portion of the introducer needle to pass proximally past
`the Spring gate. The proximal movement of the introducer
`
`17
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`

`3
`needle into the needle Shield is facilitated by a tapered
`portion of the introducer needle immediately proximal of the
`enlarged diameter portion that ensures a Smooth transition
`from the proximal portion of the introducer needle to the
`enlarged diameter portion. Once the distally facing shoulder
`is proximal of the Spring gate, the biasing mechanism forces
`the Spring gate into engagement with the shaft of the
`introducer needle. This ensures that the introducer needle
`engages the Spring gate So the tines extend up past the
`introducer needle. If a clinician then tried to advance the
`introducer needle distally, the distally facing shoulder would
`butt up against the Spring gate which in turn would butt up
`against the distal wall of the cavity in the main body portion
`and prevent the introducer needle from being moved distally.
`Thus the sharp distal tip of the introducer needle would be
`prevented from being reexposed distally from the needle
`shield.
`A variation of the Spring gate discussed above is a leaf
`Spring. The leaf Spring has a proximal wall, a Support leg and
`a locking leg. The Support leg and the locking leg are
`configured into a generally V-shape, with the apex of the V
`facing distally. The locking leg is contoured to approximate
`a portion of the circumference of the introducer needle and
`rides along the introducer needle shaft. The configuration of
`the leaf Spring ensures that the locking leg is biased toward
`the introducer needle but can be moved down away from the
`introducer needle So that the locking leg can ride over the
`enlarged diameter portion as the introducer needle is moved
`proximally into the needle shield. Once the distally facing
`shoulder is moved proximally of the proximal end of the
`locking leg of the leaf Spring, the locking leg moves back
`into contact with the shaft of the introducer needle. If the
`introducer needle is moved distally, the proximal end of the
`locking leg of the leaf Spring will engage the distally facing
`shoulder and prevent further distal movement of the intro
`ducer needle.
`An alternative means for engaging the distally facing
`shoulder is a tube formed in the main body portion. The tube
`is coaxially located in the longitudinal passage of the main
`body portion and includes at least one movable lanced
`protrusion or tab that extends inwardly into the tube.
`Because the tab is movable, the distally facing shoulder can
`move proximally past the tab. Once the introducer needle
`has been withdrawn proximally into the needle shield such
`that the tab is distal of the distally facing shoulder, any distal
`movement of the introducer needle will be prevented when
`the distally facing shoulder engages the tab.
`Yet another means for engaging the distally facing shoul
`der is a disk that is formed in or added to the main body
`portion. The disk is coaxially located in the longitudinal
`passage of the main body portion and defines a through hole
`and at least one proximally oriented, inwardly extending tab
`adjacent the through hole. The tab is also preferably oriented
`at an angle less than 90 degrees to the introducer needle. The
`through hole should be slightly larger than the diameter of
`the introducer needle to allow the major portion of the
`introducer needle to pass therethrough. Because the tab is
`movable, the distally facing shoulder can move proximally
`past the tab. Once the introducer needle has been withdrawn
`proximally into the needle shield such that the tab is distal
`of the distally facing shoulder, any distal movement of the
`introducer needle will be prevented when the distally facing
`shoulder engages the tab. In addition, Since the tab is
`proximally oriented at an angle less than 90 degrees to the
`introducer needle, additional force would be required to
`allow the introducer needle to be subsequently moved
`distally. And in certain instances a distally facing shoulder
`
`4
`may not be necessary as long as the tab engages the Surface
`of the introducer needle if it is moved distally.
`The distal portion of the needle shield includes a plurality
`of longitudinally extending fingers and radially inwardly
`extending projections that engage the proximal end of the
`catheter hub. This ensures that the needle shield remains
`engaged with the catheter until the introducer needle has
`been completely removed from the catheter and is safely
`shielded in the needle shield.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`The preferred embodiments are illustrated in the drawings
`in which like reference numerals refer to like elements and
`in which:
`FIG. 1 is a perspective view of the catheter and introducer
`needle assembly with the needle shield of this invention;
`FIG. 2 is an enlarged elevation view, partially in croSS
`Section, of the distal portion of the introducer needle used in
`the catheter and introducer needle assembly with the needle
`shield of this invention;
`FIG. 3 is a cross-sectional view of a first embodiment of
`the needle shield and the distal portion of the introducer
`needle with the sharp distal tip of the introducer needle
`extending from the distal end of the needle shield;
`FIG. 4 is a cross-sectional view of the first embodiment of
`the needle shield and the distal portion of the introducer
`needle with the sharp distal tip of the introducer needle
`withdrawn into the needle shield;
`FIG. 5 is a cross-sectional view of the first embodiment of
`the needle shield and the distal portion of the introducer
`needle with the sharp distal tip of the introducer needle
`locked in the needle shield in its distal most position;
`FIG. 6 is a perspective view of the Spring gate that is used
`in the embodiment of FIGS. 3 through 5 to lock the
`introducer needle in the needle Shield;
`FIG. 7 is a perspective croSS-Sectional view of a Second
`embodiment of the needle shield and the distal portion of the
`introducer needle with the sharp distal tip of the introducer
`needle extending from the distal end of the needle shield;
`FIG. 8 is a cross-sectional view of the second embodiment
`of the needle shield and the distal portion of the introducer
`needle with the sharp distal tip of the introducer needle
`locked in the needle shield;
`FIG. 9 is a perspective view of the leaf spring that is used
`in the embodiment of FIGS. 7 and 8 to lock the introducer
`needle in the needle shield;
`FIG. 10 is a cross-sectional view of a third embodiment
`of the needle shield and the distal portion of the introducer
`needle with the sharp distal tip of the introducer needle
`extending from the distal end of the needle shield;
`FIG. 11 is a cross-sectional view of the third embodiment
`of the needle shield and the distal portion of the introducer
`needle with the sharp distal tip of the introducer needle
`locked in the needle shield;
`FIG. 12 is a perspective cross-sectional view of the tube
`that is used in the embodiment of FIGS. 10 and 11 to lock
`the introducer needle in the needle shield;
`FIG. 13 is a cross-sectional view of a fourth embodiment
`of the needle shield and the distal portion of the introducer
`needle with the sharp distal tip of the introducer needle
`extending from the distal end of in the needle shield;
`FIG. 14 is a cross-sectional view of the fourth embodi
`ment of the needle shield and the distal portion of the
`introducer needle with the sharp distal tip of the introducer
`needle locked in the needle Shield; and
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`FIG. 15 is a perspective cross-sectional view of the disk
`that is used in the embodiment of FIGS. 13 and 14 to lock
`the introducer needle in the needle shield.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`AS used herein, the term “proximal' refers to a location on
`the catheter and introducer needle assembly with the needle
`Shield of this invention closest to the clinician using the
`device and farthest from the patient in connection with
`whom the device is used. Conversely, the term “distal” refers
`to a location on the catheter and introducer needle assembly
`of this invention farthest from the clinician using the device
`and closest to the patient in connection with whom the
`device is used.
`Although this invention is described herein in connection
`with a typical peripheral IV catheter, it is to be understood
`that this invention is applicable to other catheterS Such as
`catheters with extension tubes and extended dwell catheters
`requiring the needle to be connected to the needle hub by a
`stylet as well as other medical devices where it is desirable
`for a needle to be shielded after use. In addition, while this
`invention is satisfied by embodiments in many different
`forms, there are shown in the drawings and herein described
`in detail, preferred embodiments of the invention with the
`Scope of the invention measured by the appended claims.
`The catheter and introducer needle assembly of this
`invention is identified generally by the numeral 10. It
`includes a catheter assembly 20 and an introducer needle
`assembly 30 that includes a needle shield 40.
`Catheter assembly 20 includes a catheter 21 that has a
`proximal end 22, a distal end 23 and a catheter hub 24
`affixed to catheter proximal end 22. Suitable materials for
`catheter 21 include, but are not limited to, thermoplastic
`resins such as polytetrafluoroethylene (PTFE), polyurethane
`and the like. Preferably, catheter 21 is formed from a
`thermoplastic hydrophilic polyurethane that Softens with
`exposure to physiological conditions present in the patient's
`body. Suitable materials for catheter hub 24 include, but are
`not limited to, thermoplastic polymeric resins Such as
`polycarbonate, polystyrene, polypropylene and the like.
`Catheter hub 24 may include a radially outwardly extending
`tab, not shown, which is useful for advancing catheter 21
`into the patient’s blood vessel.
`Introducer needle assembly 30 includes introducer needle
`31 having a sharp distal tip 32 defined by bevel 32a and a
`proximal end 33 connected to needle hub 34. Introducer
`needle 31 is preferably formed from stainless steel. Needle
`hub 34 can include an integrated flashback chamber having
`an open proximal end 35. Needle hub 34 is preferably
`formed from the same types of materials that are used to
`form catheter hub 24. Preferably, open proximal end 35 is
`closed to fluid flow by a porous plug 36 which allows air but
`not fluid to flow therethrough.
`Introducer needle assembly 30 also includes needle shield
`40 which includes main body portion 41 and which in turn
`defines a longitudinally extending passage 42 having a
`proximal portion 43, a distal portion 44 and a distal opening
`45. This allows introducer needle 31 to extend longitudinally
`through main body portion 41. The diameter of proximal
`portion 43, distal portion 44 and distal opening 45 is slightly
`larger than the diameter of the main portion of introducer
`needle 31. This allows the main portion of introducer needle
`31 to easily pass through proximal portion 43, distal portion
`44 and distal opening 45. Main body portion 41 also
`includes a radially extending flange 46 and a plurality of
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`6
`longitudinally extending fingers 47. FingerS 47 also include
`radially inwardly directed projections 48. Fingers 47 and
`projections 48 engage catheter hub 24 to hold introducer
`needle assembly 30 together with catheter assembly 20.
`Introducer needle 31 includes a distally facing shoulder
`37, an enlarged diameter portion 38 and a tapered proximal
`portion 39. See FIG. 2. Preferably, distally facing shoulder
`37, enlarged diameter portion 38 and tapered proximal
`portion 39 are formed on introducer needle 31 by centerless
`grinding a larger diameter introducer needle. Enlarged diam
`eter portion 38 should have a diameter greater than the
`diameter of proximal portion 43. This ensures that intro
`ducer needle 31 cannot be pulled in a proximal direction
`completely out of needle Shield 40 because enlarged diam
`eter portion 38 blocks further movement of introducer
`needle 31 through proximal portion 43. Alternatively, a
`washer 49 having an opening therein with a diameter Smaller
`than the diameter of enlarged diameter portion 38 can be
`placed over the distal opening to proximal portion 43 of
`longitudinally extending passage 42 to prevent enlarged
`diameter portion 38 from passing into proximal portion 43.
`The annulus formed by distally facing shoulder 37 against
`the shaft of introducer needle 31 should have a diameter of
`at least about 0.002 inches. It has been Surprisingly found
`that this dimension is Sufficient, when used in conjunction
`with needle shield 40 of this invention, to prevent introducer
`needle 31 from being moved distally out of needle shield 40
`after introducer needle 31 has been withdrawn proximally
`into needle shield 40 to lock sharp distal tip 32 in needle
`shield 40. To ensure a sufficiently large diameter for the
`annulus of distally facing shoulder 37, that portion of
`introducer needle 31 immediately distal to distally facing
`shoulder 37 can be formed with a slightly increasing taper
`from distally facing shoulder 37 toward the distal end of
`introducer needle 31. This taper can be formed by grinding
`that portion of introducer needle 31 immediately distal of
`distally facing shoulder 37.
`The means for engaging distally facing shoulder 37 of
`introducer needle 31 can take many forms. For example, as
`shown in FIGS. 3 through 6, a spring gate 50 can be used to
`lock introducer needle 31 in place in needle shield 40.
`Spring gate 50 is located in a hollow cavity portion 48 of
`main body portion 41 of needle shield 40 and about intro
`ducer needle 31. Spring gate 50 has a generally Ushape with
`a pair of tines 51 that allow introducer needle 31 to pass
`through spring gate 50 between tines 51. The distance
`between times 51 is slightly larger than the diameter of the
`main portion of introducer needle 31 and is less than the
`diameter of enlarged diameter portion 38. A biasing mecha
`nism 55 forces spring gate 50 up into contact with introducer
`needle 31 and ensures that Spring gate 50 remains engaged
`with introducer needle 31. Biasing mechanism 55 may take
`any appropriate form. For example, it may be a helical
`Spring as shown in the FIGS. or it may be a compressible
`rubber-like material that acts as a Spring. Spring gate 50 also
`includes a Seat 52 that extends generally perpendicular to
`tines 51 to ensure that Spring gate 50 maintains contact with
`biasing mechanism 55 and remains in proper position.
`When introducer needle 31 is withdrawn proximally into
`needle shield 40, introducer needle 31 rides past tines 51. As
`tapered proximal portion 39 passes by tines 51, Spring gate
`50 is forced downwardly against the bias of biasing mecha
`nism 55 to allow enlarged diameter portion 38 to pass
`proximally past Spring gate 50. Once enlarged diameter
`portion 38 is proximal of Spring gate 50, biasing mechanism
`55 forces Spring gate back into engagement with introducer
`needle 31. When enlarged diameter portion 38 is proximal of
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`7
`spring gate 50, sharp distal tip 32 defined by bevel 32a is
`proximal of distal opening 45 and is thus Safely located in
`needle shield 40. Distal movement of introducer needle 31
`is prevented because distally facing shoulder 37 engages
`tines 51 which in turn engage the distal wall of cavity 48 to
`prevent distal movement of enlarged portion 38 into distal
`portion 44 of longitudinally extending passage 42. Thus, if
`a clinician then tried to advance introducer needle 31
`distally, biasing mechanism 55 would ensure that Spring gate
`50 is in contact with the distal portion of the shaft of
`introducer needle 31 and distally facing shoulder 37 would
`butt up against Spring gate 50 which in turn would butt up
`against the distal wall of cavity 48. This would prevent
`introducer needle 31 from being moved distally and thus
`prevent sharp distal tip 32 of introducer needle 31 from
`being reexposed from needle Shield 40. And as discussed
`above, further proximal movement of introducer needle 31
`from needle shield 40 is prevented because enlarged diam
`eter portion 38 blocks further proximal movement of intro
`ducer needle 31 through proximal portion 43.
`A variation of Spring gate 50 discussed above is to use a
`leaf spring 60. See FIGS. 7 through 9. Leaf spring 60 has a
`proximal wall 61 defining an opening 62 therein aligned
`with proximal portion 43 of longitudinally extending pas
`Sage 42. Proximal wall 61 is generally perpendicular to the
`longitudinal axis of needle shield 40. Preferably the diam
`eter of opening 62 is slightly larger than the diameter of the
`shaft of introducer needle 31 but Smaller than the diameter
`of enlarged diameter portion 38. Leaf spring 60 also has a
`Support leg 63 and a locking leg 64 which are configured
`into a generally V-shape lying on its side, with the apex of
`the V facing distally. This V-shaped configuration ensures
`that locking leg 64 is biased toward introducer needle 31.
`Locking leg 64 is contoured along its proximal portion to
`form a generally Semi-circular cross-section to approximate
`a portion of the circumference of introducer needle 31.
`Locking leg 64 rides along the shaft of introducer needle
`31 as introducer needle 31 is withdrawn proximally into
`needle shield 40. Locking leg 64 rides over tapered proximal
`portion 39 and enlarged diameter portion 38 as introducer
`needle 31 continues to be withdrawn into needle shield 40.
`Tapered proximal portion 39 facilitates movement of
`enlarged diameter portion 38 past locking leg 64. Once
`enlarged diameter portion 38 and distally facing shoulder 37
`are moved proximally of the proximal end of locking leg 64,
`locking leg 64 moves back into contact with the Shaft of
`introducer needle 31. If introducer needle 31 is moved
`distally, the proximal end of locking leg 64 will engage
`distally facing shoulder 37 and prevent further distal move
`ment of introducer needle 31. Further proximal movement
`of introducer needle 31 is prevented by the engagement of
`enlarged diameter portion 38 with proximal wall 61.
`Another alternative means for engaging distally facing
`shoulder 37 is a tube 70 located in needle shield 40. See
`FIGS. 10 through 12. Tube 70 is coaxially located in
`longitudinally extending passage 42 and includes at least
`one movable lanced tab 71 that extends inwardly into tube
`70 in a proximal direction. Preferably two such tabs 71 are
`formed on opposite sides of tube 70. Because tabs 71 are
`movable, tapered proximal portion 39 and enlarged diameter
`portion 38 can move past the proximal ends of tabs 71 as
`introducer needle 31 is withdrawn proximally into needle
`shield 40. Again the proximal movement of introducer
`needle 31 is facilitated by proximal tapered portion 39. Once
`introducer needle 31 has been withdrawn proximally into
`needle shield 40 such that tabs 71 are distal of distally facing
`shoulder 37, any distal movement of introducer needle 31
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`US 6,379,333 B1
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`8
`will be prevented by the engagement of the proximal ends of
`tabs 71 with distally facing shoulder 37. Further proximal
`movement of introducer needle 31 is prevented by the
`engagement of enlarged diameter portion 38 with proximal
`portion 43.
`Yet another alternative means for engaging distally facing
`shoulder 37 is a disk 80 located in needle shield 40. See
`FIGS. 13 through 15. Disk 80 is located in cavity 48 of main
`body portion 41 of needle shield 40 and about introducer
`needle 31. Disk 80 defines a through hole 81 that has a
`diameter slightly larger than the diameter of introducer
`needle 31. This allows introducer needle 31 to freely pass
`through disk 80. Disk 80 also includes at least one but
`preferably a plurality of movable tabs 82 that are proximally
`oriented and extend inwardly toward the proximal end of
`introducer needle 31. The ends of tabs 82 define the cir
`cumference of through hole 81. Preferably tabs 82 are
`oriented at an angle less than 90 degrees with respect to
`introducer needle 31 as seen in FIGS. 13 through 15.
`Because tabs 82 are proximally oriented and movable,
`tapered proximal portion 39 and enlarged diameter portion
`38 can move easily past the proximal ends of tabs 82 as
`introducer needle 31 is withdrawn proximally into needle
`shield 40. Again the proximal movement of introducer
`needle 31 is facilitated by proximal tapered portion 39. Once
`introducer needle 31 has been withdrawn proximally into
`needle shield 40 such that tabs 82 are distal of distally facing
`shoulder 37, any distal movement of introducer needle 31
`will be prevented by the engagement of the proximal ends of
`tabs 82 with distally facing shoulder 37. Further proximal
`movement of introducer needle 31 is prevented by the
`engagement of enlarged diameter portion 38 with proximal
`portion 43 or washer 49.
`The generally proximal orientation of tabs 82 prevents
`unwanted distal movement of introducer needle 31.