BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present invention relates to a safety needle device including a needle safety shield for protecting users from a used needle tip, such as for use in a blood collection set for safe and convenient handling of needles used in blood collection procedures.
2. Description of Related Art
[0002] Disposable medical devices having medical needles are used for administering medication or withdrawing fluid from the body of a patient. Such disposable medical devices typically include blood collecting needles, fluid handling needles, and assemblies thereof. Current medical practice requires that fluid containers and needle assemblies used in such devices be inexpensive and readily disposable. Existing blood collection devices often employ some form of durable holder onto which disposable medical needles and fluid collection tubes may be mounted. A blood collection device of this nature may be assembled prior to use and then discarded after use.
[0003] A blood collection device or intravenous (IV) infusion device typically includes a needle cannula having a proximal end, a pointed distal end, and a lumen extending therebetween. The proximal end of the needle cannula is securely mounted in a plastic hub defining a central passage that communicates with the lumen extending through the needle cannula. A thin, flexible thermoplastic tube is connected to the hub and communicates with the lumen of the needle cannula. The end of the plastic tube remote from the needle cannula may include a fixture for connecting the needle cannula to a holder or other receptacle. The specific construction of the fixture will depend upon the characteristics of the receptacle to which the fixture is to be connected.
[0004] In order to reduce the risk of incurring an accidental needle-stick wound, protection of used needle cannulas becomes important. With concern about infection and transmission of diseases, methods and devices to enclose or cover the used needle cannula have become very important and in great demand in the medical field. For example, needle assemblies often employ a safety shield that can be moved into shielding engagement with a used needle cannula to minimize risk of an accidental needle stick.
[0005] Some needle safety shields are referred to as "tip guards" and include a small rigid guard that may be telescoped along the length of the needle cannula and extended over the pointed distal end of the needle cannula for protection. Such conventional tip guards may include some form of tether for limiting the travel of the tip guard to the length of the needle cannula. An example of the foregoing is disclosed by
U.S. Patent No. 5,176,655 to McCormick et al. The McCormick et al. patent discloses the use of flexible loop-like straps for limiting the distal movement of a tip guard.
[0006] Needle shields that incorporate movable tip guards are typically manually actuated. For example,
U.S. Patent Nos. Re. 36,447 and
Re. 36,398, both to Byrne et al., disclose a safety device for a hypodermic needle that includes a plastic sheath, which is used to cover the puncture tip of the needle. The plastic sheath incorporates a thumb guard, which the user of the safety device may grasp to move the plastic sheath to a position covering the puncture tip of the needle.
U.S. Patent No. 5,951,525 to Thorne et al. discloses a manually operated safety needle apparatus that includes two pairs of opposed legs adapted to move the tip guard of the apparatus to a position covering the used needle cannula.
U.S. Patent Nos. 5,562,637 and
5,562,636, both to Utterburg, disclose a rectangular needle protector sheath for use with a needle cannula that may be extended over the needle cannula after it is used. Other prior art devices, such as those disclosed by
U.S. Patent Nos. 5,290,264 to Utterberg and
5,192,275 to Burns, provide "grippable" members attached to the tip guards to facilitate moving the tip guards to a position covering the puncture tip of a needle cannula. In addition to providing gripping members for moving the tip guards, prior art devices in this area often include flexible wings, which are used as means for securing the needle assemblies to the body of a patient during a medical procedure. Examples of "winged" needle assemblies may be found in
U.S. Patent Nos. 5,120,320 to Fayngold; and
5,154,699;
5,088,982; and
5,085,639 all to Ryan. Other prior art in this area includes
U.S. Patent Nos. 5,266,072 and
5,112,311, both to Utterberg et al., which also disclose guarded winged needle assemblies.
[0007] U.S. Patent Application Publication No. 2002/0099339 to Niermann discloses a passive safety blood collection set which includes a tip guard slidably movable along a needle cannula. The tip guard is mounted to a needle hub through a pair of collapsible leaves, which are collapsed onto themselves and held in place by a packaging cover. In use, the practitioner holds the leaves in the collapsed or folded state to remove the cover, and then releases the leaves enabling them to unfold to propel the tip guard distally.
[0008] Conventional tip guards, such as those discussed hereinabove, often include a structure that lockingly engages over the pointed distal end of the used needle cannula to prevent a re-exposure of the needle cannula. The structure for preventing the re-exposure of the needle cannula may include a metallic spring clip or a transverse wall formed integrally with one end of the tip guard. An example of a metallic spring clip is disclosed by the McCormick et al. patent discussed previously. Conventional tip guards, such as those discussed hereinabove, often further require extensive mechanics for positioning the tip guard over the needle cannula. This results in complex arrangements that are costly to manufacture and assemble. Additionally, operation of the needle assemblies to move the tip guard into the proper position over the pointed distal end of the needle cannula requires substantial manual manipulation by the user of the device, exposing the user to potential needle-stick wounds.
[0009] U.S. Patent Application Publication No. 2003/0078540 to Saulenas et al. discloses a retractable push button needle assembly, in which a needle is attached to a hub and extends through a barrel. A push button actuator extends from the hub and is in interference engagement with the barrel. Activation is accomplished with a user actively pushing the push button into the barrel, thereby causing the needle to retract within the barrel based on a spring disposed between the hub and the barrel.
[0010] Furthermore,
US 6,547,762 to Botich et al. disclosed a catheter insertion device. The device includes a mechanism allowing an operator to control retraction of a needle, connected to a flashback chamber, whereby the chamber receives a portion of blood from the needle to indicate to an operator that the needle is inserted in a vein. The device further includes a needle retainer having a forward and a rearward portion. The forward portion abuts with the hub of the catheter when the catheter is mounted to the insertion device. The rearward portion includes a release lever having a latch being pivotable between a locked position and an unlocked position.
SUMMARY OF THE INVENTION
[0011] A need exists for a shielding needle assembly that achieves secure and effective shielding of a used needle cannula, and which is simple to manufacture and easy to operate. Additionally, a need exists for a needle assembly, such as for use in a blood collection set, that is passively operated during a normal blood collection procedure.
[0012] The invention is defined in claim 1. Advantageous embodiments are set out in the dependent claims.
[0013] Further details and advantages of the present invention will become apparent from the following detailed description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014]
FIG. 1 is a perspective view of a shielding blood collection set including a needle device in accordance with an embodiment of the present invention, having a releasable packaging cover disposed at a distal end of the needle device.
FIG. 2 is a longitudinal cross-sectional view of the needle device shown in FIG. 1.
FIG. 3 is a longitudinal cross-sectional view of the needle device shown in FIG. 1, showing a user manipulating the needle device.
FIG. 4 is a longitudinal cross-sectional view of the needle device shown in FIG. 1, showing the user applying radial pressure to the needle device and the subsequent removal of the packaging cover.
FIG. 5 is a cross-sectional view of the needle device shown in FIG. 1, showing a needle cannula inserted into the body of a patient.
FIG. 6 is a longitudinal cross-sectional view of the needle device shown in FIG. 1, showing the needle device after the user has substantially released the radial pressure allowing shielding of the needle cannula.
FIG. 7 is a longitudinal cross-sectional view of the needle device shown in FIG. 1, showing the final disposition with shielding of the needle cannula.
FIG. 8 is a perspective view showing the direction of forces for actuation of the shielding needle device.
FIG. 9 is a perspective view of a shielding blood collection set including a needle device in accordance with another embodiment of the present invention, having a releasable packaging cover disposed at a distal end of the needle device.
FIG. 10 is an exploded perspective view of the specific elements of the needle device shown in FIG. 9.
FIG. 11 is a side view of the hub of the needle device of FIG. 9.
FIG. 12 is a perspective view showing the direction of forces for actuation of the shielding needle device of FIG. 9.
FIG. 13 is a perspective view showing of the shielding needle device of FIG. 9 with the packaging cover removed in the retracted position with the needle cannula exposed for use.
FIG. 14 is a perspective view showing of the shielding needle device of FIG. 9 in the extended position with the shield encompassing the needle cannula.
FIG. 15 is a longitudinal cross-sectional view of the needle device taken along lines 15-15 of FIG. 9.
FIG. 16 is a longitudinal cross-sectional view of the needle device taken along lines 16-16 of FIG. 13.
FIG. 17 is a longitudinal cross-sectional view of the needle device taken along lines 17-17 of FIG. 14.
FIG. 18 is a partial cross-sectional view of the needle device in the extended position as shown in the FIG. 14, depicting the locking elements for maintaining the shield in the shielding position.
FIG. 19 is a perspective view of a packaging cover in accordance with the embodiment of FIG. 9.
FIG. 20 is a perspective view of a shielding blood collection set including a needle device in accordance with a further embodiment of the present invention, having a releasable packaging cover disposed at a distal end of the needle device.
FIG. 21 is a longitudinal cross-sectional view of the needle device of FIG. 20.
FIG. 22 is an exploded perspective view of a hub of the needle device of FIG. 20.
FIG. 23A is a side view of a hub of the needle device of FIG. 20.
FIG. 23B is a side view of an alternate hub useful in the needle device of FIG. 20.
FIG. 24 is a side view of a shield of the needle device of FIG. 20.
FIG. 25 is a top cross-sectional view of the needle device of FIG. 20, shown with the packaging cover removed and in the first position ready for use.
FIG. 26 is a perspective view showing the direction of forces for actuation of the shielding needle device of FIG. 20.
FIG. 27 is a perspective view showing of the shielding needle device of FIG. 20 with the packaging cover removed and with a user's fingers maintaining the needle device in the first position with the needle cannula exposed for use.
FIG. 28 is a perspective view showing of the shielding needle device of FIG. 20 in the first position after the user's fingers are released during activation.
FIG. 29 is a perspective view showing of the shielding needle device of FIG. 20 in the second position with the shield encompassing the needle cannula.
FIG. 30 is a side view of the shielding needle device of FIG. 20 shown in the second position with the shield encompassing the needle cannula.
FIG. 31 is a top cross-sectional view of the needle device of FIG. 20, shown in the second position with the shield encompassing the needle cannula.
FIG. 32 is a longitudinal cross-sectional view of the needle device of FIG. 20, shown in the second position with the shield encompassing the needle cannula.
FIG. 33 is a longitudinal cross-sectional similar to FIG. 32, but including the alternate hub of FIG. 23B.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Referring to the drawings in which like reference characters refer to like parts throughout the several views thereof, FIG. 1 illustrates generally a blood collection set 10 in accordance with an embodiment of the present invention and its related features. The present invention is generally described herein in terms of a safety shielding needle assembly for use in a blood collection set, and encompasses a shielding needle assembly, as well as a blood collection set incorporating shielding needle assemblies. It is contemplated that the shielding needle assembly may be incorporated into other medical devices in alternate embodiments of the invention, such as intravenous assemblies, fluid infusion sets, hypodermic syringes, and the like.
[0016] As shown generally in FIG. 1, the blood collection set
10 includes a safety shielding needle device or assembly
12, a flexible tube
14 extending from the needle device or assembly
12 and having first and second ends
15, 16, and a protective cap or shield such as packaging cover
18 removably mounted to the needle assembly
12 opposite tube
14, such as through a frictional engagement. Needle assembly
12 extends from a first end
15 of flexible tube
14, while the second end
16 of flexible tube
14 is adapted for connection with a receptacle for blood collection. For example, the second end
16 of flexible tube
14 may be provided with a proximal fitting
17 which is adapted for engagement with a conventional needle holder (not shown) as is known in the art. Fitting
17 may further define a hub element including a non-patient needle assembly (not shown) as is commonly known in the art for use in blood collection sets. Alternatively, fitting
17 may define a luer connector that can be mated with an appropriate connector of a separate device as is known in the art, such as for mating with an infusion set for infusing a medication into a patient.
[0017] With general reference to FIGS. 2-8, one embodiment of the invention defines the shielding needle assembly
12 generally including a needle cannula
20, a hub
30, a needle cannula safety shield member
70, and a drive member
80 for moving the safety shield
70. The needle cannula
20 includes a rearward or proximal end
22 and an opposing forward or distal end
24, with a lumen
26 extending through needle cannula
20 from the proximal end
22 to the distal end
24. The distal end
24 of needle cannula
20 may be beveled to define a sharp puncture tip
28, such as an intravenous puncture tip. The puncture tip
28 is provided for insertion into a patient's blood vessel, such as a vein, and is therefore designed to provide ease of insertion and minimal discomfort during venipuncture. Needle cannula
20 is desirably constructed of a medical grade metallic material, such as surgical steel or the like.
[0018] The needle assembly
12 further includes a hub
30. The hub
30 is generally tubular or cylindrical in shape, and may be a unitary structure, desirably molded from a resilient thermoplastic material, or may be a multi-component structure. The hub
30 includes a rearward or proximal end
32 and a forward or distal end
34. The proximal end
32 of the hub
30 includes an external portion or structure
36 for mating with the first end
15 of the flexible tube
14, and an internal portion or structure
38 for engaging the drive member
80, which is preferably in the form of a coil spring or like element for biasing the safety shield
70 in the manner described herein. The external and internal portions or structures
36, 38 are generally tubular shaped components adapted to cooperate with the flexible tube
14 and drive member
80, respectively. The external structure
36 may be adapted to cooperate with the flexible tube
14 in a friction-fit manner, and a suitable medical grade adhesive may be used to secure the connection.
[0019] As depicted in FIGS. 2-8, the needle cannula
20 and the hub
30 may be separate parts that are preferably fixedly attached and secured through an appropriate medical grade adhesive, for example, epoxy or the like. In particular, the proximal end
22 of the needle cannula
20 is supported by the proximal end
32 of the hub
30 and, in particular, the internal structure
38 formed in the proximal end
32 of the hub
30. For this purpose, the hub
30 defines a passageway or opening
40 extending between the internal structure
38 and the external structure
36 for receiving and securing the proximal end
22 of the needle cannula
20 therein. The opening
40 preferably extends through the proximal end
32 of the hub
30 and is used to place the needle assembly
12 in fluid communication with the flexible tube
14, or another medical device, such as a tube holder, syringe, and like devices. The proximal end
22 of the needle cannula
20 may extend into the opening
40 and extend into the external structure
36 provided on the proximal end
32 of the hub
30. The needle cannula
20 is secured within the opening
40 by an appropriate medical grade adhesive, and generally extends toward the distal end of the needle assembly
12 through an internal passageway
42 extending through hub
30, with the puncture tip
28 at distal end
24 of needle cannula
20 extending through the forward or distal end
34 of hub
30.
[0020] The needle assembly
12 further includes a shield member such as safety shield
70, which extends telescopically about needle cannula
20, such as in a generally coaxial manner. The safety shield
70 is in telescoping association with the hub
30, such that at least one of hub
30 and/or shield
70 are adapted for relative movement with respect to the other in a generally axial direction, that is in a general direction with respect to the general longitudinal axis L of needle assembly
12. More particularly, the shield
70 and/or the hub
30 are telescopically movable with respect to one another between a first position of the needle assembly
12 in which the puncture tip
28 of needle cannula
20 is exposed from a forward end of the shield
70, and a second position in which the shield
70 generally encompasses the needle cannula
20 and, more particularly, the puncture tip
28, as will be described in more detail herein. The safety shield
70 is generally tubular or cylindrical in shape, and may be a unitary structure, desirably molded from a thermoplastic material, including a rearward or proximal end
72 and a forward or distal end
74. The distal end
74 defines a central opening
76 through which the needle cannula
20 extends. The central opening
76 permits relative telescopic movement between the safety shield
70 and the needle cannula
20 between the first and second positions of the needle assembly
12 noted above.
[0021] The needle assembly
12 further includes drive member
80 extending between the hub
30 and the shield
70, providing a biasing force to bias the hub
30 and the shield
70 axially or longitudinally away from each other. Drive member
80 is generally coaxially positioned with the shield
70 and/or the hub
30, with the needle assembly
12 in the first position. The drive member
80 may be in the form of a coil compression spring or like biasing element and is generally adapted to move the safety shield
70 and/or the hub
30 with respect to each other between the first position and the second position of the needle assembly
12. The drive member
80 has a proximal end
82 and a distal end
84. The proximal end
82 is generally disposed on the internal structure
38 formed internally at the proximal end
32 of the hub
30. The distal end
84 is generally in contact with a portion of the shield
70, such as an interior surface
86 defined within the distal end
74 of the safety shield
70. The biasing force of the drive member
80 is described herein in terms of biasing the hub
30 and shield
70 with respect to each other, such as a biasing force biasing the hub
30 an the shield
70 axially away from each other. It is noted that activation of the needle assembly
12 is based on this biasing force of drive member
80 causing movement of either the hub
30 or the shield
70, or movement of both the hub
30 and the shield
70 with respect to each other. For example, it the user is holding the hub
30 during activation, the biasing member
80 will cause the shield
70 to extend or move distally with respect to hub
30 to the second shielding position of needle assembly
12. On the other hand, if the user is holding the shield
70 during activation, the biasing member
80 will cause the hub
30 to retract or move proximally with respect to shield
70 to the second shielding position of the needle assembly
12.
[0022] A packaging cover
18 may also be provided on the needle assembly
12, such as at the distal end
34 of hub
30, and is preferably provided on the needle assembly
12 during the manufacturing process.
[0023] In a general sense, the hub
30 and the shield
70 are maintained from movement with respect to each other against the bias of the drive member
80 to maintain needle assembly
12 in the first position with puncture tip
28 extending from the forward end of the shield
70. The hub
30 and shield
70 may be maintained in this manner through external pressure applied externally to the structure of needle assembly
12 by a user during the normal use of needle assembly
12. Such external pressure provides an engagement between the hub
30 and the shield
70 to prevent the drive member
80 from biasing the hub
30 and the shield
70 away from each other in a longitudinal direction. Generally speaking, in an initial state such as during shipment and storage, packaging cover or cover
18 may be adapted to apply external pressure to the hub
30 and/or the shield
70 to prevent the drive member
80 from biasing the hub
30 and the shield
70 axially away from each other. Generally during use, a user grasps needle assembly
12 to apply external pressure to the hub
30 and/or the shield
70 and removes the packaging cover
18, with the user maintaining the external pressure on the hub
30 and/or the shield
70 until activation of the needle assembly
12 is desired. In this manner, needle assembly
12 represents a passively activatable structure in that activation occurs during the normal use of the needle assembly
12.
[0024] The hub
30 and safety shield
70 may be provided in various arrangements, as will now be discussed in more detail with reference to specific embodiments of the invention.
[0025] FIGS. 2-8 depict a specific embodiment of the invention in which the shield
70 is retained within the hub
30 against the bias of drive member
80. In particular, as shown in FIGS. 2-8, the hub
30 includes two opposing release members
44. The release members
44 generally extend along opposing sides
46, 48 of the hub
30 and form part of the body of the hub
30. The release members
44 are generally adapted to maintain the safety shield
70 and drive member
80 in a pre-actuated state or position within the body of the hub
30, and also operate to release or actuate the drive member
80, which is generally operable to move the safety shield
70 to a shielding position relative to the needle cannula
20, as discussed in detail herein.
[0026] The release members
44 are desirably pivotally connected to the hub
30, for example, by respective hinge structures
50 (i.e., hinges). The release members
44 are preferably integrally-molded with the body of the hub
30, which is preferably formed of molded plastic material. The hinge structures
50 are thus formed integrally (i.e., as a living hinge) with the release members
44 and the body of the hub
30. The hinge structures
50 permit the release members
44 to pivot relative to the body of the hub
30 and, in particular, to pivot inward toward a central longitudinal axis
L of the blood collection set
10 and shielding needle assembly
12. Alternatively, the release members
44 may be formed separately from the hub
30 and connected thereto by conventional hinges. The release members
44 produce an angle vertex opening towards the distal end
34 of the hub
30. The release members
44 partially form the sidewall of the hub
30, but may pivotally extend inward into the hub
30.
[0027] The opposing release members
44 further include respective finger tabs
52 which provide locations for a user's fingers when manipulating the blood collection set
10 and needle assembly
12. The finger tabs
52 may include raised structures or protrusions
54, such as bumps, for improving the handling characteristics of the needle assembly
12 when manipulated by the user. The release members
44 each include distal ends
56 formed with opposing locking tabs
58, 60. The locking tabs
58, 60 are generally formed as inward-projecting locking tabs
58 and outward-projecting locking tabs
60, which are also referred to herein as first and second locking tabs
58, 60. The first or inward-projecting locking tabs
58 on the release members
44 are generally adapted to engage the safety shield
70, and the second or outward-projecting locking tabs
60 are generally adapted to engage the packaging cover
18, as discussed further herein.
[0028] In particular, in the embodiment of FIGS. 2-8, the safety shield
70 extends generally coaxially about needle cannula
20 and is movable along needle cannula
20 between a first or retracted position coaxially received within the hub
30 (See FIGS. 2-5), and a second or extended position (See FIGS. 6 and 7) generally encompassing the needle cannula
20 and, more particularly, the puncture tip
28. The drive member
80 is generally adapted to move the safety shield
70 axially along the needle cannula
20 from the retracted position to the extended position. In particular, the distal end
84 of the drive member
80 is generally in contact with the distal end
74 of the safety shield
70 and, in particular, an internal side
86 of the distal end
74 of the safety shield
70. The engagement of the distal end
84 of the drive member
80 with the distal end
74 of the safety shield
70 forms the physical interface between the drive member
80 and the safety shield
70 for moving the safety shield
70 from the retracted position to the extended position. The distal end
74 of the safety shield
70 further includes an outward-facing or distal end surface
88, which engages the first or inward-projection locking tabs
58 in the retracted position of the safety shield
70.
[0029] Alternatively, the release members
44 may represent the sidewalls of the hub
30, while they are radially flexible inwardly due to the physical structure of the hub
30. For example, the release members
44 (i.e., hub sidewalls) may be constructed to flex radially inwardly when external lateral pressure is applied to opposing sides of the hub
30. To facilitate this flexing, the opposing sidewalls of the hub
30 may be constructed or molded with a thinner thickness than the proximal or distal portions of the hub
30, allowing for flexing of the opposing sides of the hub
30 at the release members
44. Such inward radial pressure at the release members
44 creates a compressive force establishing a frictional engagement against the safety shield
70 to hold the safety shield
70 in the retracted position. Such an arrangement may also include the locking tabs
58, 60 for further retention of the safety shield
70.
[0030] The packaging cover
18 is provided on the distal end
34 of the hub
30 and is preferably secured to the hub
30 during manufacturing and assembly of the needle assembly
12. The packaging cover
18 is preferably in frictional engagement with the distal end
34 of the hub
30, and is generally adapted to maintain the needle assembly
12 in the pre-actuated state or condition shown, for example, in FIGS. 2-4, with the safety shield
70 in the retracted position. For this purpose, the packaging cover
18 may be formed with an internal locking groove
90, which is engaged by the second or outward-projecting locking tabs
60 formed at the distal ends
56 of the release members
44. The engagement of the outward-projecting locking tabs
60 secures the packaging cover
18 on the distal end
34 of the hub
30, with the aid of the drive member
80, until the needle assembly
12 is actuated by a user.
[0031] In the pre-actuated or "pre-packaged" state or condition of the needle assembly
12, the drive member
80 exerts a distally-directed force on the internal side
86 of the safety shield
70, which urges the distal end
74 of the safety shield
70 into engagement or contact with the first or inward-projecting locking tabs
58 formed on the distal ends
56 of the release members
44. In particular, the distal end surface
88 of the safety shield
70 is urged into contact or engagement with the first or inward-projecting locking tabs
58 on the distal ends
56 of the release members
44. Without the presence of the packaging cover
18, the distally-directed force acting on the distal ends
56 of the release members
44 would cause the release members
44 to pivot outward about their respective hinge structures
50. However, this distally-directed force is prevented from prematurely actuating the needle assembly
12 by the presence of the packaging cover
18, which provides a counter-acting radial force maintaining the compression of the drive member
80 within the safety shield
70 and hub
30. The engagement of the first or outward-projecting locking tabs
60 with the locking groove
90 in the packaging cover
18 prevents premature removal of the packaging cover
18 from the distal end
34 of the hub
30, and therefore premature actuation of the needle assembly
12.
[0032] An optional mechanism for retaining the packaging cover
18 onto hub
30 includes using the locking tabs
60 as external threads to ride within corresponding internal threads (not shown) in the packaging cover
18. In this embodiment, the internal threads would act more like slots than true threads, and the packaging cover
18 would have to be rotated to a position where the locking tabs
60 (i.e., external threads) would allow for the packaging cover
18 to be removed from the hub
30. An alternative configuration to the foregoing could include the locking tabs
60 engaging internal circumferential slots in the packaging cover
18 which connect to internal axial slots in the packaging cover
18. In such a variation, rotation of the packaging cover
18 would cause the locking tabs
60 to slide within the circumferential slots until reaching the axial slots, which would allow the packaging cover
18 to be removed from the hub
30.
[0033] The blood collection set
10 may be packaged in a conventional blister package (not shown). Prior to use, the blood collection set
10 is removed from its package and, if necessary, the second end
16 of the flexible tube
14 may be connected to an appropriate receptacle for providing fluid communication with the lumen
28 through the needle cannula
20. In use, the blood collection set
10 is provided with the needle assembly
12 and flexible tube
14 extending from needle assembly
12 and connected to an appropriate device (not shown), such as a blood collection receptacle.
[0034] To use the blood collection set
10 and needle assembly
12, the user generally grasps the opposing finger tabs
52 provided on the needle assembly
12, as shown in FIGS. 3-5. The user then applies radial pressure to the finger tabs
52. FIG. 8 illustrates the direction of radially applied pressure that is necessary to begin actuation of the blood collection set
10 and needle assembly
12. As the user applies radial pressure to the finger tabs
52, the release members
44 will generally pivot inward toward the central longitudinal axis
L of the blood collection set
10 and needle assembly
12. The release members
44 will generally pivot about their respective hinge structures
50, and will displace inward toward the central longitudinal axis
L of the blood collection set
10 and needle assembly
12, as shown in FIG. 4. As shown in FIG. 4, the radial inward displacement of the release members
44 causes the second or outward-projection locking tabs
60 formed at the distal end
56 of the release members
44 to disengage substantially automatically from the locking groove
90 in the packaging cover
18. With the disengagement of the locking tabs
60 from the locking groove
90, the packaging cover
18 is releasable from secured engagement with the hub
30, and may be removed from the distal end
34 of the hub
30 by the user. The inward movement of the release members
44 generally reduces the diameter (i.e., cross-sectional area) of the distal end
34 of the hub
30 and automatically releases the packaging cover
18 from the distal end
34.
[0035] The user preferably maintains the radial force applied to the finger tabs
52, which causes the release members
44 to remain in substantially laterally-extending positions along the lateral sides
46, 48 of the hub
30. In this configuration, the first or inward-projection locking tabs
58 remain engaged with the outward-facing or distal end surface
88 at the distal end
74 of the safety shield
70, and prevents the drive member
80 from moving the safety shield
70 from the retracted position to the extended position. In particular, the distal end surface
88 of the safety shield
70 engages opposing inward-facing surfaces
92 on the first or inward-projection locking tabs
58 formed on the release members
44. The radial pressure applied by the user maintains the engagement of the locking tabs
58 with the distal end
74 of the safety shield
70, thereby maintaining the safety shield
70 in the retracted position and counteracting the distally-directed biasing force of the drive member
80. The radial pressure applied to the finger tabs
52 generally takes the place of the removed packaging cover
18 for maintaining the safety shield
70 in the retracted position and counteracting the biasing force of the drive member
80.
[0036] The user may then urge the puncture tip
28 at distal end
24 of the needle cannula
20 into a targeted blood vessel of a patient in order to conduct a blood collection procedure or other procedure as desired. When the user releases the radial pressure applied to the finger tabs
52, the drive member
80 is free to exert a distally-directed biasing force on the distal end
74 of the safety shield
70. In particular, with the release of the radial pressure, the drive member
80 urges the outward-facing or distal end surface
88 of the safety shield
70 to slide along the inward-facing surfaces
92 on the inward-projecting locking tabs
58, and generally urges the release members
44 to spread radially apart. The inward-facing surfaces
92 of the locking tabs
58 may be tapered to facilitate the sliding movement of the distal end surface
88 of the safety shield
70, and the concurrent outward-directed movement of the release members
44. As used in this disclosure, the term "release of radial pressure" and like phrases used to describe how the user actuates the needle assembly
12 is not intended to be limited to the complete discontinuing of radial pressure. This terminology is specifically intended to include such a complete discontinuing of radial pressure, such as the user totally removing his or her fingers from the finger tabs
52, as well as a partial or sequential lessening or reducing of radial pressure on the finger tabs
52 sufficient to allow the drive member
80 to move the locking tabs
58 out of engagement with the distal end
74 of the safety shield
70 and move the safety shield
70 to the extended or shielding position. The biasing force inherent in the drive member
80 as well as the profile of any interfering surfaces between the hub
30 and the shield
70 will determine the amount of lessening of the radial pressure required to allow the needle assembly
12 to actuate.
[0037] Once the locking tabs
58 are displaced radially out of engagement with the distal end
74 of the safety shield
70, the safety shield
70 is completely unrestrained and subject entirely to the distally-directed biasing force of the drive member
80. The drive member
80 propels the safety shield
70 distally along needle cannula
20 in an axial direction of arrow
100 (see FIG. 6), with the safety shield
70 sliding or gliding along needle cannula
20 toward distal end
24. During an actual blood collection procedure, the distal movement of the safety shield
70 will terminate when the distal end
74 of the safety shield
70 contacts the skin of the patient, as shown in FIG. 5. The drive member
80 still exerts a distally-directed biasing force on the safety shield
70, but this force is resolved by the frictional force that acts on the needle cannula
20, as a result of being in the blood vessel of the patient. The user may then proceed to complete the blood collection procedure, for example, using evacuated blood collection tubes or a syringe. The user then proceeds to remove the blood collection set
10 from the blood vessel of the patient using the finger tabs
52. As the needle cannula
20 is removed from the blood vessel of the patient, the safety shield
70 is urged by the drive member
80 to move closer to the distal end
24 of the needle cannula
20. As the needle cannula
20 is fully removed from the patient's blood vessel, the safety shield
70 is urged by the drive member
80 to fully encompass the needle cannula
20, as generally depicted in FIGS. 6 and 7. The drive member
80 now extends internally between the distal end
74 of the safety shield
70 and the internal structure
38 formed within the hub
30 at the proximal end
32 of the hub
30, and exerts a biasing force that will aid in preventing the re-emergence of the puncture tip
28 from the central opening
76 in the distal end
74 of the safety shield
70.
[0038] The safety shield
70 may further includes an external locking structure
102 for securing the safety shield
70 in the extended position, once the needle assembly
12 has been actuated. The external locking structure
102 may incorporate an external locking recess or groove
104, which is configured to be engaged by the inward-projecting locking tabs
58 when the safety shield
70 is moved to the extended position. In particular, when the safety shield
70 is moved to the extended position by the drive member
80, the locking tabs
58 preferably snap into engagement with the locking recess
104. It will be appreciated that the external locking recess
104 need not be continuous about the circumference of the safety shield
70. Likewise, the internal locking groove
90 in the packaging cover
18 need not be continuous around the internal circumference of the packaging cover
18.
[0039] An alternate version of the above-described needle assembly is depicted in a further embodiment described with particular reference to FIGS. 9-19. The embodiment of FIGS. 9-19 generally depicts a specific embodiment of the invention in which the shield is retained within the hub against the bias of drive member through a dorsal grasping structure, with a dorsal member and dorsal gripping structure adapted for providing engagement between the hub and the shield upon application of external pressure thereto to retain the shield with respect to the hub against the bias of the drive member. In the embodiment described with reference to FIGS. 9-19, similar components performing similar functions will be numbered identically to those components of FIGS. 1-8, except that a suffix "a" will be used to identify those similar components in FIGS. 9-19.
[0040] Needle assembly
12a as shown in FIGS. 9-19 includes a housing in the form of hub
30a similar to that described above in connection with FIGS. 1-8, with a rearward or proximal end
32a and a forward or distal end
34a, and including an external structure
36a for mating with the first end
15a of the flexible tube
14a, and an internal structure
38a for engaging the drive member
80a and for supporting needle cannula
20a. The second end
16a of the flexible tube
15a may also include a fixture
17a for connection with a separate medical device, for example, to provide a blood collection set
10a. The proximal end
22a of needle cannula
20a is supported at internal structure
38a, and extends through the internal passageway
42a of hub
30a, with puncture tip
28a extending out from the distal end
34a thereof.
[0041] Shield
70a extends generally coaxially about needle cannula
20a and is movable along needle cannula
20a between a first or retracted position coaxially received within the passageway
42a of hub
30a as shown in FIGS. 11 and 15, and a second or extended position generally encompassing the needle cannula
20a and, more particularly, the puncture tip
28a as shown in FIGS. 16 and 17. The drive member
80a is generally adapted to move the shield
70a axially along the needle cannula
20a from the retracted position to the extended position. In particular, the distal end
84a of the drive member
80a is generally in contact with a portion of the shield
70a such as an abutment structure
78a provided on an external surface of the shield
70a. The engagement of the distal end
84a of the drive member
80a with the abutment structure
78a of the shield
70a forms the physical interface between the drive member
80a and the shield
70a for moving the shield
70a from the retracted position to the extended position.
[0042] Needle assembly
12a includes structure adapted to maintain the shield
70a and drive member
80a in a pre-actuated state or position within the body of the hub
30a and to release or actuate the drive member
80a, in a similar manner as with release members
44 described above with reference to FIGS. 1-8. In particular, in the present embodiment, engagement between the hub
30a and the shield
70a is provided through an actuation mechanism in the form of a dorsal grasping structure
108a including a dorsal member
110a extending from an external surface of the hub
30a and a grip structure
112a extending from an external surface of the shield
70a. Dorsal grasping structure
108a is generally symmetrically aligned with the bevel-up orientation of the puncture tip
28a of the needle cannula
20a.
[0043] More particularly, hub
30a includes dorsal member
110a, which extends dorsally from a top surface thereof in the form of a generally planar spine member extending in a plane corresponding to longitudinal axis
L defined by the needle cannula
20a. Shield
70a includes a main body portion such as tubular body
71a, with a grip structure
112a extending from the top surface of the body
71a of shield
70a at the forward or distal end
74a thereof. Grip structure
112a of shield
70a includes a profile generally corresponding to the dorsal member
110a, and may be in the form of at least one, and preferably a pair of flexibly resilient planar leafs
114a, 116a, uniting at forward ends thereof through a bridge
118a. In this manner, the grip structure
112a extends from the body
71a of shield
70a through the bridge
118a, with planar leafs
114a, 116a extending toward the rearward or proximal end
72a of the shield
70a along a top end of the body
71a. The planar leafs
114a, 116a are spaced from each other to define an opening or gap
120a therebetween for accommodating the spine of dorsal member
110a therein when the shield
70a is in the retracted position within hub
30a. The planar leafs
114a, 116a are resilient members which can be bent or flexed toward each other, and are therefore essentially pivotally connected through the bridge
118a in a hinged manner. The shield
70a is preferably molded as a single structure of molded plastic material including the body
71a, bridge
118a and planar leafs
114a, 116a integrally formed. Additionally, one or more bumps
122a may be provided on an external surface of one or both of planar leafs
114a, 116a, providing a tactile surface for the user to grasp the grip structure
112a during use.
[0044] Shield
70a extends coaxially within the internal passageway
42a of hub
30a. To assist in accommodating the grip structure
112a of shield
70a therein, hub
30a may include a cutaway portion
62a at a top surface adjacent distal end
34a thereof. In this manner, the bridge
118a of shield
70a can be slidably accommodated within cutaway portion
62a of hub
30a when the shield
70a is maintained in the first position retracted within the hub
30a.
[0045] External pressure applied between the grip structure
112a of the shield
70a and the dorsal member
110a of the hub
30a maintains the shield
70a in the retracted position against the bias of the drive member
80a. In particular, in the embodiment of FIGS. 9-19, external pressure applied between the planar leafs
114a, 116a, establishes frictional engagement between one or both of the planar leafs
114a, 116a and dorsal member
110a of hub
30a, thereby maintaining the shield
30a in fixed relation with respect to the hub
30a against the bias of the drive member
80a, as will be discussed in more detail herein. Such inward pressure at the planar leafs
114a, 116a creates a compressive force establishing a frictional engagement against the spine of dorsal member
110a, thereby holding the safety shield
70a in the retracted position with respect to the hub
30a. It is contemplated that the grip structure
112a may include only a single planar leaf extending from the shield
70a, in which case engagement of the single planar leaf with the dorsal member
110a of the hub
30a is accomplished by gripping directly between the single planar leaf and the dorsal member
110a between the user's fingers.
[0046] Moreover, the planar leafs
114a, 116a, and the dorsal member
110a may include corresponding structure adapted for interference engagement therebetween when external pressure is applied. For example, dorsal member
110a may include one or more detents
124a on an external surface thereof, and planar leafs
114a, 116a may include one or more corresponding protrusions or protuberances
126a on a corresponding surface within gap
120a. The opposing planar leafs
114a, 116a may also include structure on external finger surfaces thereof for providing a tactile feel for a user's fingers when manipulating the needle assembly
12a and during use, such as raised structures or protrusions in the form of bumps
122a.
[0047] A packaging cover
18a may also be provided on the distal end
34a of the hub
30a in a similar manner as described above with respect to FIGS. 1-8. The packaging cover
18a is preferably in frictional engagement with the hub
30a, and is generally adapted to maintain the needle assembly
12a in the pre-actuated state with the safety shield
70a in the retracted position. In this manner, the packaging cover
18a includes opposing longitudinal arms
128a and
130a, with an opening
132a extending therebetween. With packaging cover
18a secured to the distal end
34a of hub
30a, longitudinal arms
128a and
130a extend rearward along opposing lateral sides of hub
30a. Longitudinal arms
128a and
130a are desirably constructed in a manner so as to be naturally biased radially inwardly, so as to exert a radially compressive force against the outer surface of hub
30a, thereby maintaining packaging cover
18a in a frictional fit over hub
30a. The packaging cover
18a may contact the distal end
74a of the shield
70a, with the radial compressive force of the longitudinal arms
128a and
130a being sufficiently strong so as to maintain shield
70a in the retracted position against the bias of drive member
80a. Moreover, the longitudinal arms
128a and
130a may be sized and shaped so as to contact at least a portion of the respective external surfaces of planar leafs
114a, 116a. In this manner, the radially compressive force exerted by the longitudinal arms
128a and
130a will be transferred to the planar leafs
114a, 116a, thereby providing an external compressive force thereagainst as depicted in FIG. 12 to further maintain shield
70a in the retracted position with respect to hub
30a. In addition or alternatively thereto, the packaging cover
18a may include structure for interlocking engagement with a portion of shield
70a as described above with reference to FIGS. 1-8, such that when planar leafs
114a, 116a are grasped during use, packaging cover
18a is released.
[0048] The hub
30a may further include a pair of wings
134a, 136a, extending laterally from opposing sides of the hub
30a. The wings
134a, 136a are fixed in relation to the hub
30a, and are desirably integrally molded with the hub
30a as a rigid structure. The wings
134a, 136a provide structure for guiding the needle assembly
12a during use thereof, and can be taped to the skin of a patient to maintain the needle assembly
12a in a fixed position during use in a medical procedure such as blood collection. Desirably, the dorsal grasping structure
108a formed by the engagement between the planar leafs
114a, 116a and dorsal member
110a has a profile larger than the profile of wings
134a, 136a. In this manner, a user is encouraged to grasp the needle assembly
12a by the dorsal grasping structure
108a for use, as opposed to grasping needle assembly
12a by attempting to bend wings
134a, 136a toward each other, as is common with conventional needle assemblies.
[0049] To use the needle assembly
12a of the embodiment set forth in FIGS. 9-19, the user generally grasps the dorsal grasping structure
108a to apply external pressure between opposing surfaces of the planar leafs
114a, 116a and the dorsal member
110a in the direction of shown in FIG. 15. As the user applies external pressure to the planar leafs
114a, 116a, the packaging cover
18a is removed from the distal end
34a of the hub
30a by the user. The user maintains the external force applied to the planar leafs
114a, 116a, which causes them to engage with the dorsal member
110a of the hub
30a in a frictional engagement, and in particular causes the protrusions
126a on the planar leafs
114a, 116a to engage the corresponding detents
124a on the dorsal member
110a in an interference engagement. In this manner, the pressure applied by the user maintains the engagement between the planar leafs
114a, 116a and the dorsal member
110a, thereby maintaining the safety shield
70a in the retracted position and counteracting the distally-directed biasing force of the drive member
80a. The radial pressure applied to the planar leafs
114a, 116a generally takes the place of the removed packaging cover
18a for maintaining the safety shield
70a in the retracted position and counteracting the biasing force of the drive member
80a.
[0050] The user may then urge the puncture tip
28a at distal end
24a of the needle cannula
20a into a targeted blood vessel of a patient in order to conduct a blood collection procedure or other procedure as desired. After proper positioning, when the user releases the applied pressure applied to the planar leafs
114a, 116a, the drive member
80a is free to exert a distally-directed biasing force on the distal end
74a of the safety shield
70a. The drive member
80a then propels the safety shield
70a distally along needle cannula
20a in an axial direction of arrow
100a in FIG. 14, with the safety shield
70a sliding or gliding along needle cannula
20a toward distal end
24a. During an actual blood collection procedure, the distal movement of the safety shield
70a will terminate when the distal end
74a of the safety shield
70a contacts the skin of the patient. The drive member
80a still exerts a distally-directed biasing force on the safety shield
70a, but this force is resolved by the frictional force that acts on the needle cannula
20a, as a result of being in the blood vessel of the patient. The user may then proceed to complete the blood collection procedure, for example, using evacuated blood collection tubes or a syringe. The user then proceeds to remove the needle assembly
12a from the blood vessel of the patient by grasping the dorsal member
110a. As the needle cannula
20a is removed from the blood vessel of the patient, the safety shield
70a is urged by the drive member
80a to move closer to the distal end
24a of the needle cannula
20a. As the needle cannula
20a is fully removed from the patient's blood vessel, the safety shield
70a is urged by the drive member
80a to fully encompass the needle cannula
20a, as generally depicted in FIGS. 14 and 17. The drive member
80a exerts a biasing force that will aid in preventing the re-emergence of the puncture tip
28a from the central opening
76a in the distal end
74a of the safety shield
70a.
[0051] The safety shield
70a and the hub
30a may further include interengaging structure for interfering engagement therebetween for securing the safety shield
70a in the extended position to prevent a return movement once the needle assembly
12a has been actuated. For example, the safety shield
70a may include external locking structure in a similar manner as described above with respect to FIGS. 1-8, such as an external locking recess or groove, which is preferably provided through abutment structure
78a in the embodiment of FIGS. 9-19, and which is configured to be engaged by the inward-projecting locking tabs
58a on opposing lateral sides of hub
30a when the safety shield
70a is moved to the extended position, as shown in FIG. 18. Needle assembly
12a can thereafter be appropriately discarded.
[0052] A further variation of the needle assembly is depicted in yet a further embodiment described with particular reference to FIGS. 20-33. The embodiment of FIGS. 20-33 generally depicts a specific embodiment of the invention in which the shield is a barrel-like structure maintained coaxially about the hub against the bias of the drive member, with one or more corresponding release tabs of the shield adapted for providing engagement with a release member of the hub upon application of external pressure thereto to maintain the shield and the hub in fixed relation against the bias of the drive member. In the embodiment described with reference to FIGS. 20-33, similar components performing similar functions will be numbered identically to those components of FIGS. 1-8, except that a suffix "b" will be used to identify those similar components in FIGS. 20-33.
[0053] Needle assembly
12b as shown in FIGS. 20-33 includes a hub
30b similar to that described above in connection with FIGS. 1-8. In particular, as shown in FIGS. 22 and 23A, the hub
30b includes a proximal end
32b, a distal end
34b and an internal passageway
42b extending between the ends. The first end
15b of flexible tubing
14b connects with the hub
30b in a manner as described above. Alternatively, portions of internal passageway
42b adjacent proximal end
32b may be dimensioned to receive the first end
15b of flexible tubing
14b. More particularly, the first end
15b of the tubing
14b may be telescoped into passageway
42b of the hub
30b and bonded in position adjacent the proximal end
32b of the hub
30b. Portions of the passageway
42b adjacent the distal end
34b of the hub
30b may also dimensioned for slidable receipt of the proximal end
22b of the needle cannula
20b.
[0054] External portions of the hub
30b may define a cylindrical portion
140b having a reduced diameter for mounting the drive member
80b thereover. A flange
142b defines a limit for proximal movement of the drive member
80b on the hub
30b and a limit for distal movement of the hub
30b relative to the shield
70b.
[0055] A release member in the form of a protrusion or button
144b extends distally outwardly from an external surface at the forward or distal end
34b of the hub
30b. The button
144b may be symmetrically aligned with the bevel-up orientation of the puncture tip
28b of the needle cannula
20b. The proximal end of the button
144b defines a surface at locking edge
146b which establishes an interference engagement with corresponding structure on the shield
70b, as will be described in more detail herein.
[0056] FIG. 23B and FIG. 33 depict an alternate version of the hub
30b which is similar to that shown in FIG. 23A, but with the button
144b being radially flexible with respect to the body of the hub
30b. In particular, in the embodiment of the hub
30b shown in FIG. 23B and FIG. 33, the button is not merely a protrusion extending outwardly from the external surface of the hub
30b, but instead extends from an actuator arm of the hub
30b which is cantilevered to extend outwardly and distally from the proximal end of hub
30b, in a similar manner as is described with respect to the hub of the retractable needle assembly of
U.S. Patent Application Publication No. 2003/0078540 to Saulenas, the disclosure of which is incorporated herein by reference. In this manner, button
144b is flexible radially inwardly. Such flexing may assist in movement of the hub
30b in the proximal direction during actation of the assembly, in that the button
144b can radially flex inwardly during retraction of the hub 30b to prevent any frictional or interference engagement with the shield
70b.
[0057] In the embodiment of FIGS. 20-33, the shield
70b may be provided as a barrel extending between proximal end
72b and distal end
74b, with an internal passageway
75b therethrough and a central opening
76b extending through the distal end
74b thereof. Desirably, the proximal end
72b and the distal end
74b define separate rearward and forward structures, respectively, which are unitarily formed, interconnected or otherwise attached together. For example, the proximal end of the shield
70b may be provided as a rearward shield structure
150b, in a cylindrical or barrel-like form. Rearward shield structure
150b has an internal diameter substantially the same as or slightly larger than the external diameter of the hub
30b, including the button
144b, and is therefore capable of accommodating hub
30b including the button
144b therethrough in a slidable manner. Rearward shield structure
150b is connected with forward shield structure
152b at a bridge section
154b. The bridge section
154b establishes the rearward shield structure
150b and the forward shield structure
152b as separate ends which are joined to each other.
[0058] The distal end
74b of the shield
70b defined by forward shield structure
152b defines an inwardly extending annular distal flange
156b with an inside diameter less than the outside diameter of the drive member
80b. Thus, distal flange
156b defines a distal stop for drive member
80b and enables drive member
80b to be compressed within the shield
70b. An internal portion of forward shield structure
152b may also define a fixed limit for distal movement of the hub
30b therein.
[0059] Needle assembly
12b includes structure adapted to maintain the hub
30b and drive member
80b in a pre-actuated state or position within the body of the shield
70b and to release or actuate the drive member
80b, in a similar manner as with release members 44 described above with reference to FIGS. 1-8. In particular, the forward shield structure
152b includes at least one, and preferably a pair of release tabs
158b, 160b on opposing lateral sides thereof. The release tabs
158b, 160b extend longitudinally along opposing sides of the forward shield structure
152b, such as in a proximal manner toward rearward shield structure
150b. The release tabs
158b, 160b are desirably integrally formed with the forward shield structure
152b, and may form structure similar to the release members
44 described above in connection with FIGS. 1-8. The release tabs
158b, 160b include distal edge surfaces
162b, 164b, respectively, as well as mating edges
166b, 168b, respectively. In a relaxed and unbiased state, the release tabs
158b, 160b naturally deflect outwardly, such as radially outwardly from the overall barrel structure of the shield
70b, with mating edges
166b, 168b, deflected away from each other. The release tabs
158b, 160b are flexible members with respect to forward shield structure
152b, and can be deflected inwardly to a biased state, such as radially inwardly to a position in which mating edges
166b and
168b substantially meet. In such a biased state of the release tabs
158b and
160b, the distal edge surfaces
162b and
164b of the opposing release tabs
158b and
160b form a perimeter edge of an opening or aperture
170b through the forward shield structure
152b. The aperture
170b thus formed is dimensioned and configured to receive button
144b, with the perimeter edge defined by the distal edge surfaces
162b and
164b configured for engaging proximal edge
146b of the button
144b.
[0060] In this manner, the hub
30b and the shield
70b can be maintained in a first position against the biasing force of the drive member
80b biasing the hub
30b and the shield
70b away from each other, i.e., biasing the hub
30b toward the proximal direction. External pressure applied between the opposing release tabs
158b and
160b of the shield
70b at the forward shield structure
152b in a radially inward direction deflects and biases the release tabs
158b and
160b against their relaxed state, causing mating edges
166b, 168b to meet, thereby establishing aperture
170b. The proximal edge
146b of button
144b is thereby in interference engagement with one or both of the distal edge surfaces
162b, 164b. As such, the drive member
80b is prevented from causing axial movement of the hub
30b and the shield
70b with respect to each other. Such pressure may also create a compressive force establishing a frictional engagement between the inner surfaces of the release tabs
158b, 160b and the external surface of the hub
30b, thus further holding the hub
30b within the shield
70b in the first position.
[0061] A packaging cover
18b is provided about the needle cannula
20b in engagement with a portion of the forward shield structure
152b, similar to that described above with respect to FIGS. 1-8. The packaging cover
18b is preferably in frictional engagement with the distal end
74b of the shield
70b at forward shield structure
152b, and is generally adapted to maintain the needle assembly
12b in the pre-actuated state with the hub
30b in the first position. Accordingly, the internal diameter of the packaging cover
18b is sized so as to exert a radially compressive force against the outer surface of the release tabs
158b, 160b so as to deflect and bias the release tabs
158b and
160b radially inwardly against their relaxed state. The outward pressure exerted by the release tabs
158b and
160b may be sufficient to frictionally maintain the packaging cover
18b in a frictional fit over forward shield structure
152b. Further, the packaging cover
18b includes structure for interlocking engagement with a portion of forward shield structure
152b in a similar manner as described above with reference the release members
44 of FIGS. 1-8, such that when the release tabs
158b and
160b are grasped during use, any such interlocking engagement with the packaging cover 18b is released.
[0062] To use the needle assembly
12b of the embodiment set forth in FIGS. 20-33, the user generally grasps the assembly at opposing sides thereof to apply external pressure between opposing surfaces of the release tabs
158b, 160b in the direction shown in FIG. 27. As the user applies external force through inwardly or radially directed pressure to the release tabs
158b, 160b, the packaging cover
18b is removed from the forward shield structure
152b at the distal end
74b of the shield
70b by the user. The user maintains the external force of the inwardly directed pressure applied to the release tabs
158b, 160b, which maintains the mating edges
166b, 168b in a position substantially meeting each other. As such, button
144b is maintained within the aperture
170b, with the proximal edge
146b of button
144b in interference engagement with distal edge surfaces
162b, 164b. In this manner, the pressure applied by the user maintains the interference engagement between the release tabs
158b, 160b and the release member of button
144b, thereby maintaining the hub
30b in the first position and counteracting the proximally-directed biasing force of the drive member
80b against the hub
30b. The radial pressure applied to the release tabs
158b, 160b generally takes the place of the removed packaging cover
18b for maintaining the hub
30b in the first position and counteracting the biasing force of the drive member
80b.
[0063] The user may then urge the puncture tip
28b at distal end
24b of the needle cannula
20b into a targeted blood vessel of a patient in order to conduct a blood collection procedure or other procedure as desired. After proper positioning, when the user releases the applied pressure applied to the release tabs
158b, 160b, the release tabs
158b, 160b deflect outwardly to their relaxed unbiased state, with mating edges
166b, 168b moving away from each other. At this point, the interference engagement between the proximal edge
146b of the button
144b and the distal edge surface
162b, 164b is released. As such, the drive member
80b is free to exert a biasing force between the hub
30b and the shield
70b, with the drive member
80b propelling the hub
30b proximally through the rearward shield structure
150b. During an actual blood collection procedure, the compressive force of the drive member
80b is insufficient to withdraw the needle cannula
20b from the patient, and instead the shield
70b will move distally and terminate when the distal end
74b of the safety shield
70b contacts the skin of the patient. The drive member
80b still exerts a biasing force between the shield
70b and the hub
30b, but this force is resolved by the frictional force that acts on the needle cannula
20b, as a result of being in the blood vessel of the patient. The user may then proceed to complete the blood collection procedure, for example using evacuated blood collection tubes or a syringe.
[0064] The user then proceeds to remove the needle assembly
12b from the blood vessel of the patient. As the needle cannula
20b is removed from the blood vessel of the patient, the safety shield
70b is urged by the drive member
80b to move closer to the distal end
24b of the needle cannula
20b. As the needle cannula
20b is fully removed from the patient's blood vessel, the safety shield
70b is urged by the drive member
80b to fully encompass the needle cannula
20b, as generally depicted in FIGS. 29 and 30. The drive member
80b exerts a biasing force that will aid in preventing the re-emergence of the puncture tip
28b from the central opening
76b in the distal end
74b of the safety shield
70b.
[0065] The safety shield
70b and the hub
30b may further include interengaging structure for interfering engagement therebetween for securing the safety shield
70b in the extended position to prevent a return movement once the needle assembly
12b has been actuated. For example, the safety shield
70b may include external locking structure in a similar manner as described above with respect to FIGS. 1-8. For example, the rearward shield structure
150b may include resiliently deflectable locking fingers or tabs
58b that are cantilevered proximally and inwardly from opposed locations. As shown in FIG. 31, each locking finger or tab
58b is adapted to engage a portion of the hub
30b when the hub
30b is in the second position with the needle cannula safely encompased within shield
70b. Needle assembly
12b can thereafter be appropriately discarded.
[0066] The particular elements of the needle assembly can be manufactured of any known materials. Desirably, the hub, the shield, and the packaging cover are individually molded from plastic materials such as polycarbonate, polypropylene, polyethylene, acrylic, polystyrene and ABS. Preferably the hub and/or the shield are molded from a transparent or translucent material to enable observation of blood or other fluid flowing through the hub during use of the device.
[0067] The shielding feature of the present invention is passively actuated upon normal usage of the device. In particular, upon removal of the packaging cover prior to insertion, the safety feature is primed and charged, ready for shielding the needle once the user releases the opposing finger tabs. Moreover, in some instances, the needle assembly may be dropped or knocked from the hand of the user before, during, or after use. The shielding feature described above will commence automatically when the needle assembly is dropped or knocked from the user's hand. Thus, the automatic shielding may be triggered by the intentional or unintentional release of the finger tabs by the user.
[0068] Additionally, a user, such as a medical practitioner, does not always enter the targeted blood vessel during the first venipuncture attempt. However, a medical practitioner typically retains a close grip on the needle assembly until the targeted blood vessel has been entered. In this instance, the continued gripping of the finger tabs will prevent the needle assembly from shielding until the targeted blood vessel has been punctured. The second attempt at accessing a targeted blood vessel generally is a very low risk procedure in which the user's hand is spaced considerably from the puncture tip of the needle cannula. Thus, the blood collection set does not involve the inconvenience of having to use a new blood collection set following each unsuccessful venipuncture attempt.
[0069] While the needle assembly of the present invention has been described in terms of various embodiments for use in connection with a blood collection system, it is further contemplated that the needle assembly could be used with other medical procedures, such as in conjunction with a conventional intravenous infusion set, which are well-known in the art for use with needle assemblies. While the present invention is satisfied by embodiments in many different forms, there is shown in the drawings and described herein in detail, the preferred embodiments of the invention, with the understanding that the present disclosure is to be considered as exemplary of the invention defined by the appended claims.