Note: Descriptions are shown in the official language in which they were submitted.
CA 02364963 2001-12-13
UNITED STATES PATENT APPLICATION
By: Jamieson William Maclean Crawford and Stefanie Livanos
FOR: BLOOD COLLECTION SET
BACKGROUND OF THE INVENTION
1. Field of the Invention
01] The subject invention relates to a blood collection set having a needle
cannula and
field that can be driven forwardly to safely shield the needle cannula.
2. Description of the Related Art
02] A prior art blood collection set includes a small diameter needle cannula
having a
nted distal end and a proximal end mounted to a thermoplastic hub. Portions of
the blood
lection set near the hub may be provided with a pair of flexible wings. The
wings can be
fed into face-to-face engagement with one another to facilitate digital
manipulation of the
X11 needle cannula. The wings then can be folded away from one another and
taped into face-
:ace engagement with the skin of the patient near a puncture site. The prior
art blood
lection set further includes a flexible plastic tube that has one end
connected to the hub and an
posed end connected to a fitting. The fitting can be placed in communication
with a reservoir
which collected blood may be directed.
03] The needle cannula of the prior art blood collection set typically is
shielded prior
end after use to prevent accidental sticks. Needle shields used with prior art
blood collection
have taken many forms. Typically, a prior art blood collection set is packaged
with a rigid
ular cap telescoped over the needle cannula to prevent accidental sticks prior
to use. This
ular cap is removed from the needle cannula immediately prior to use of the
blood collection
Most prior art blood collection sets further include a second shield that is
telescoped over
needle cannula and hub. The second shield may include at least one slot
through which
CA 02364963 2001-12-13
wings of the prior art hub may extend. Thus, the medical technician who uses
the prior art blood
collection set will 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 proximal and distal ends. The hub
also has inner and
outer tubes that extend between the proximal and distal ends. The inner tube
includes a passage
that extends continuously between the proximal and distal ends of the hub. A
portion of the
inner tube at the distal end 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 hub. The inner and outer tubes are connected to one another adjacent the
proximal end of the
hub. However, a cylindrical space exists at other locations between the inner
and outer tubes and
is open from the distal end of the hub. The outer tube includes an aperture
extending
therethrough and into the cylindrical space between the inner and outer tubes
at a location near
the proximal end of the hub.
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(0007] 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 through
the hub both communicate with the passage through the flexible tubing. The
flexible tubing
further 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.
[0008] The blood collection set may fizrther 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
engaged with the hub. The rigid tubular safety cap may be removed immediately
prior to use of
the blood collection set.
[0009] The blood collection set further includes a safety shield that is
telescoped within
the outer tube of the hub and telescoped over the inner tube of the hub and
cannula. Thus, the
shield can be moved 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 hub.
[0010] The blood collection set fiuther comprises a retainer for releasably
retaining the
shield in the proximal position relative to the hub and the needle cannula and
against the stored
energy of the biasing means. The retainer may define a resiliently deflectable
actuating finger
that projects into the aperture in the outer tube of the hub. The end of the
actuating finger may
be depressed to separate the actuating finger from the aperture and enable the
shield to be
propelled toward the distal position in response to forces exerted by the
biasing means.
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DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a perspective view of a blood collection set in accordance
with the
subject invention with the needle exposed.
[0012] FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. 1.
[0013] FIG. 3 is a perspective view similar to FIG. l, but showing the needle
of the blood
collection set in the shielded condition.
DETAILED DESCRIPTION
[0014] A blood collection set in accordance with the subject invention is
identified
generally by the numeral 10 in FIGS. 1-3. Blood collection set 10 includes a
needle assembly 12
which comprises a needle hub 14, a needle cannula 16, a safety cap (not
shown), a shield 20 and
a spring 22. Hub 14 includes a proximal end 32 and a distal end 34. A tubular
inner wall 36
extends from proximal end 32 to distal end 34 and is connected to needle
cannula 16 as in the
prior embodiments. A tubular outer wall 38 is disposed in concentric spaced
relationship around
tubular inner wall 36. Tubular outer wall 38 is formed with a retention
aperture 40 extending
therethrough at a location near proximal end 32. Wings 66 extend transversely
from tubular
outer wall as in the prior embodiments.
(0015] Shield 20 is telescoped between inner and outer walls 36 and 38 of hub
14 and
includes a proximal end 42 and a distal end 44. A resiliently deflectable
finger 46 projects
proximally and outwardly from a location between proximal and distal ends 42
and 44. Finger
46 includes an actuator 48 that is releasably engaged in retention aperture 40
of outer wall 38 on
hub 14. Spring 22 is captured in a compressed condition between proximal end
32 of hub 14 and
shield 20.
[0016] Needle assembly 12 is used in the conventional manner. After withdrawal
of
needle cannula 16 from the patient, shield 20 is activated merely by exerting
a pressing force on
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actuator 48. This pressing force will disengage actuator 48 from aperture 40
and shield 20 will
be propelled distally into surrounding shielding disposition relative to
needle cannula 16. After
sufficient distal movement, resiliently deflectable finger 46 will pass beyond
distal end 34 of hub
14 and will resiliently move into a position aligned with portions of outer
wall 38 at distal end
34. Thus, re-exposure of needle cannula is substantially prevented. On the
other hand,
engagement between an inwardly directed flange at distal end 34 of hub 14 and
an outwardly
directed flange on shield 20 prevents complete separation of shield 20 from
hub 14.
