Note: Descriptions are shown in the official language in which they were submitted.
CA 02366864 2002-O1-03
Express Mail Label No.: E. 16966327US P-4523/12
Date of Deposit: ~o,,en~br~ 1 ~~ 1co ~
BLOOD COLLECTION ASSEMBLY
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001) The subject invention relates to a blood collection set having a needle
cannula and
a shield that can be driven forwardly to safely shield the needle cartnula.'
2. Description of the Related Art
[0002] A prior art blood collection set includes a small diameter needle
cannula having a
pointed distal end and a proximal end mounted to a thermoplastic hub. Portions
of the blood
collection set near the hub may be provided with a pair of flexible wings. The
wings can be
folded into face-to-face engagement with one another to facilitate digital
manipulation of the
small needle cannula. The wings then can be folded away from one another and
taped into face-
to-face engagement with the skin of the patient near a puncture site. The
prior art blood
collection set further includes a flexible plastic tube that has one end
connected to the hub and an
opposed end connected to a fitting. The fitting can be placed in communication
with a reservoir
to which collected blood may be directed.
[0003] The needle cannula of the prior art blood collection set typically is
shielded prior
to and after use to prevent accidental sticks. Needle shields used with prior
art blood collection
sets have taken many forms. Typically, a prior art blood collection set is
packaged with a rigid
tubular cap telescoped over the needle cannula to prevent accidental sticks
prior to use. This
tubular cap is removed from the needle cannula immediately prior to use of the
blood collection
set. Most prior art blood collection sets further include a second shield that
is telescoped over
the needle cannula and hub. The second shield may include at least one slot
through which
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wings of the prior art hub may extend. Thus, the medical technician who uses
the prior art blood
collection set wilt hold the wings of the needle hub in one hand and the
shield in the other hand
after removing the needle cannula from the patient or blood donor. The wings
then are slid
proximally relative to the shield, thereby drawing the needle cannula into the
shield. Some prior
art shields are configured to engage the wings when the needle cannula has
been shielded to
make a re-exposure of the needle cannula difficult.
[0004] The digital manipulation that is required to shield the used needle
cannula of a
prior art blood collection set creates the potential for generating the
accidental needle stick that
the shield is intended to avoid. In particular, it is undesirable to rely upon
a shielding that
requires two hands to be moved in opposite directions in proximity to the
point of a used needle
cannula. Accordingly, the inventors herein have recognized the desirability of
providing an
automatically shieldable needle cannula for a blood collection set.
SUMMARY OF THE INVENTION
[0005] The subject invention relates to a blood collection set which comprises
a needle
cannula having a proximal end, a pointed distal end and a lumen extending
therebetween.
[0006] The blood collection set further includes a hub that may be molded from
a
thermoplastic material. The hub includes opposite proximal and distal ends.
The hub ftuther
includes concentric spaced apart inner and outer tubes extending between the
proximal and distal
ends. The inner and outer tubes are connected to one another at their
respective proximal ends.
However, the inner and outer tubes of the hub are not connected at the distal
end. Thus, a
cylindrical space extends proximally from the distal end of the hub and
between the inner and
outer tubes. A passage extends continuously between the proximal and distal
ends of the inner
tube of the hub. The distal end of the inner tube of the hub is securely
mounted to the proximal
end of the needle cannula. Thus the lumen through the needle cannula
communicates with the
passage through the inner tube of the hub.
z
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[0007] A pair of deflectable fins projecting transversely from opposite sides
of the outer
tube of the hub at locations adjacent the distal end of the outer tube. The
fins can be rotated
toward one another about the outer tube and into a position where the rotated
fins can be engaged
by a thumb and forefinger for gripping and manipulating the blood collection
set. At least one of
the fins further includes a projection that extends at least partly across the
opening between the
inner and outer tubes at the distal end of the hub when the fins project
transversely from the outer
tube. However, rotation of the fins toward one another will cause the
projection to rotate away
from the opening to the cylindrical space between the inner and outer tubes.
[0008] The hub may further include a dorsal fin that projects radially
outwardly from the
outer tube at a location adjacent the distal end of the hub. The transverse
fins can be rotated into
engagement against the dorsal fin. Thus, the dorsal fin permits manipulation
of the blood
collection set when the transverse fins are in their unbiased condition and
extending away from
one another. However, the transverse fins can be rotated toward one another
and into
engagement with opposite surfaces of the dorsal fin. Thus, a user can
simultaneously grip the
transverse fins and the dorsal fin for manipulating the blood collection set.
The outer tube may
fiuther include at least one locking aperture extending through the outer tube
at a location near
the distal end of the outer tube.
[0009] The blood collection set may further include a length of flexible
tubing having
opposed proximal and distal ends. The distal end of the flexible tubing may be
connected to the
proximal end of the hub such that the lumen through the needle cannula and the
passage thmugh
the hub both communicate with the passage through the flexible tubing. The
flexible tubing
fiirther includes a proximal end that may be connected to a fitting. The
fitting may comprise a
needle cannula that enables the blood collection set to be placed in
communication with a
reservoir for receiving a sample of blood. The tubing and the fitting may be
of conventional
design.
(0010] The blood collection set may further include a substantially rigid
generally tubular
safety cap mounted over the needle cannula for protection against accidental
needle sticks prior
to use of the blood collection set. The safety cap may include a proximal end
that is frictionally
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engaged with the hub. The rigid tubular safety cap may be removed immediately
prior to use of
the blood collection set.
[0011 ] The blood collection set further includes a safety shield that is
telescoped over at
least portions of the inner tube of the hub and cannula and at least partly
within the outer tube.
Thus, the safety shield is movable within the cylindrical space between the
inner and outer tubes
of the hub from a proximal position, where the needle cannula is exposed, to a
distal position,
where the needle cannula is safely shielded. Biasing means are provided
between the shield and
the hub for urging the shield to the distal position. The biasing means may be
a coil spring that
surrounds a portion of the inner tube of the hub.
[0012] The projections on the transverse fins function as a retainer for
releasably
retaining the shield in the proximal position relative to the hub and the
needle cannuIa and
against the stored energy of the biasing means. Rotation of the transverse
fins towards one
another and/or toward the dorsal fin moves the projections of the transverse
fins away from the
opening to the cylindrical space between the inner and outer tubes of the hub.
Thus, the safety
shield is free to move in response to the stored energy of the biasing means.
The safety shields
and the hub may further include a lock for preventing complete removal of the
safety shield from
the hub when the transverse fins are moved into a position that permits the
distal movement of
the shield. The lock' may further prevent a return proximal movement that
could re-expose the
used needle cannula.
DESCRIPTION OF THE DRAWINGS
r
[0013] FIG. 1 is a perspective view of a blood collection set in accordance
with the
subject invention.
[0014] FIG. 2 is a top plan view of the needle assembly shown in FIG. 1 with
the safety
cap removed.
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(0015] FIG. 3 is a top plan view similar to FIG. 2 but showing the shield
after actuation
by the wings.
[0016] FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. 3.
DETAILED DESCRIPTION
[0017] A blood collection set in accordance with the subject invention is
identified by the
numeral 10 in FIGS 1-4. Blood collection set 10 includes a needle assembly 12
with a hub 14, a
needle cannula 16, a safety cap 18, a safety shield 20, and a spring 22. Blood
collection set 10
also includes a flexible tube 24 and a fitting 30. Fitting 30 is configured to
be placed in
communication with a reservoir into which blood drawn by needle assembly 12
may be
deposited.
(0018] Hub 14 includes an annular proximal wall 32, a distal end 34, a tubular
inner wall
36 (FIG. 4) extending distally from proximal wall 32 and a tubular outer wall
38 extending
distally from proximal wall 32. Outer wall 38 is in spaced concentric
relationship to tubular
inner wall 36. Portions of tubular inner wall 36 at distal end 34 of hub 14
are mounted to needle
cannula 16 substantially as with the first embodiment. Outer wall 38 of hub 14
has an inwardly
directed stop flange 39. Additionally, outer wall 38 is provided with a
locking aperture 40 in
proximity to distal end 34.
[0019] Outer wall 38 includes a pair of actuator wings 42 projecting
transversely
therefrom. Actuator wings 42 include retainer projections 44 extending toward
needle cannula
16 and partly across outer wall 38 at distal end 34 of hub 14. As explained
further herein,
projections 44 retain safety shield 20 within outer wall 38. Actuator wings 42
can be rotated
toward one another substantially as in the previous embodiment. However, such
rotation of
wings 42 moves projections 44 away from needle cannula 16 and out of blocking
engagement
with shield 20. Outer wall 38 includes a dorsal fin 45 projecting transversely
therefrom and at a
location separated from actuator wings 42 by approximately 90°.
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[0020) Shield 20 initially is slidably disposed within outer wall 38 and in
surrounding
relationship to inner wall 36 of hub 14. Shield 20 can be moved from the
proximal position
shown in FIGS. 2 and 3 to the distal position shown in FIGS. 3 and 4. Shield
20 defines a length
sufficient to cover all of needle cannula 16 when shield 20 is in its distal
position of FIGS. 3 and
4.
[0021) As shown most clearly in FIG. 4, shield 20 includes locking projections
48 at
' proximal end portions thereof. Locking projections 48 are dimensioned and
disposed to
lockingly engage stop flange 39 and locking aperture 40 when shield 20 is in
its distal position.
Spring 22 is disposed between proximal wall 32 of hub 14 and locking
projections 48 of shield
20. Thus, in the ready-to-use condition of FIGS. 3 and 4, spring 22 is in a
compressed
condition.
[0022] Needle assembly 12 is used by initially gripping dorsal fin 45 and then
removing
safety cap 18. Needle cannula 16 then is inserted into the patient to draw a
sample of blood.
Needle assembly 12 then can be gripped by dorsal fin 45 to remove needle
cannula 16 from the
patient. Upon removal, actuator wings 42 are rotated toward one another. This
rotation causes
retainer projections 44 to rotate away from shield 22, and thereby removes
blocking forces that
had been exerted on shield 20. As a result, spring 22 is released and propels
shield 20 distally
and into shielding engagement over needle cannula 16. After sufficient distal
movement,
locking projections 48 at the proximal end of shield 20 will engage stop
flange 39 of outer wall
38. Simultaneously, locking projections 48 will engage in lock aperture 40.
Thus, shield 20 is
locked in a distal position protectively surrounding needle cannula 16.
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