Note: Descriptions are shown in the official language in which they were submitted.
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NEEDLE ASSEMBLY INCLUDING OBTURATOR WITH SAFETY RESET
BACKGROUND OF THE INVENTION
[0001] This invention relates generally to needle assemblies and more
particularly
to needle assemblies that have shields to cover sharp ends of needles.
[0002] Needle assemblies of the present invention have particular, although
not
exclusive application in the field of medicine and have needles with sharpened
ends for use in
piercing the skin to withdraw materials as needed. The needle is supported by
some other
structure that is used to manipulate the needle. The most common example is a
syringe.
However, some needle assemblies require the application of substantial force
in use. One
example of such a needle assembly is a bone marrow needle assembly that is
used to
penetrate cortical bone to reach the intramedullary canal for withdrawing
liquid or a biopsy
sample of bore marrow, or for infusing the canal with a selected material.
Typically, the
needle includes a cannula and a stylet that is received in the cannula and has
a hard, sharp tip
that can penetrate cortical bone. The tip projects out from the distal end of
the cannula. The
stylet can be withdrawn from the cannula after the needle penetrates the bone
to the so that
the hollow interior of the cannula can be used as a conduit for liquid or a
receptacle to collect
bone marrow.
[0003] In order to penetrate cortical bone, a substantial amount of force must
be
applied to the needle. For this reason, bone needle assemblies conventionally
mount the
needle in a handle that is sized and shaped so that the technician may
comfortably grip the
handle and apply the force necessary to penetrate the bone. The handle may
comprise two
handle members that can be selectively put together and separated for
inserting the stylet into
the cannula and removing the stylet from the cannula. A proximal handle member
mounts
the stylet and a distal handle member mounts the cannula. "Proximal" and
"distal" refer to
the relative location of the handle members to the technician when the needle
assembly is in
use. The proximal handle member is in contact with the palm of the
technician's hand in use,
and the distal handle member is on the opposite side of the proximal handle
member from the
palm.
[0004] Some needle assemblies, including bone needle assemblies, have
associated
safety mechanisms that shield the sharp tips of the needle components when
they are not
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needed and after they have become contaminated with potentially hazardous
biological
material. The safety mechanism includes a shield and usually a mechanism for
locking the
shield in place over the sharpened tip. As a matter of convenience, and to
enhance the
probability that the safety feature will be used by a medical technician, the
safety feature may
be secured to the needle assembly. However, the safety feature must be
retained out of the
way when the needle assembly is being used, for example, to collect a liquid
or solid sample
from the intramedullary canal. The safety feature then must be released from
its stowed
position and moved to an operative position in which its shield covers the
sharpened tip of the
needle.
In cases where a sample (e.g., a bone marrow sample) is collected by the
needle assembly,
the sample has to be removed from the needle assembly. An obturator is a
device including a
long thin shaft, and in some cases includes a blunt tip, that can fit inside
the cannula for
pushing the sample of bone marrow out of the cannula. This can be done with
the safety
shield in position covering the sharp end of the cannula to protect the
technician. In some
cases it will be determined that the sample is not satisfactory and it will be
necessary to
obtain a second sample. It is not necessary to use a new needle assembly,
because the needle
assembly would be reused on the same patient. However, the shield is held in
place over the
tip of the needle assembly making it unusable for a collecting a second
sample. Accordingly,
there is a need for a needle assembly that can be easily reset for multiple
uses, but which will
not result in inadvertent release of the safety shield.
SUMMARY OF THE INVENTION
[00051 In one aspect of the present invention, a needle assembly generally
comprises mounting structure and a needle mounted on the mounting structure
and extending
outwardly therefrom. The needle has a longitudinal axis, a sharp end and a
central axial
passageway. A safety shield associated with the needle comprises a tubular
housing adapted
for movement relative to the needle between a stowed position in which the
tubular housing
is spaced from the sharp end of the needle and a deployed position in which
the tubular
housing covers the sharp end. A locking mechanism is adapted to releasably
lock the tubular
housing in position covering the sharp end of the needle. The tubular housing
has distal and
proximal ends and at least one peripheral slot extending radially inwardly
from the periphery
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and axially along the housing from the distal end of the housing. A reset key
adapted to
actuate release of the locking mechanism to permit the shield to be moved
relative to the
needle comprises a support and at least one rib on the support sized and
arranged for
reception in the peripheral slot of the tubular housing for entering the
tubular housing to
actuate release of the locking mechanism.
[0006] In another aspect of the present invention, a reset key for use in
releasing a
locking mechanism of a safety shield covering a sharp tip of a needle for
movement of the
safety shield relative to the needle generally comprises a support defining a
central open
space sized and shaped for receiving at least a portion of the safety shield.
Ribs mounted on
the support and located at positions spaced circumferentially of each other
generally around
the perimeter of the central open space are shaped and arranged for reception
in slots on the
safety shield when the safety shield is received in the central open space for
actuating release
of the locking mechanism.
[0007] In yet another aspect of the present invention, a reset key for use in
releasing a locking mechanism of a safety shield covering a sharp tip of a
needle for
movement of the safety shield relative to the needle generally comprises a
shroud sized and
shaped for receiving at least a majority of the safety shield therein. A rib
associated with the
shroud can actuate release of the locking mechanism when the safety shield is
received in the
shroud.
[0008] In still another aspect of the present invention, a needle assembly
generally
comprises mounting structure and a needle mounted on the mounting structure
and extending
outwardly therefrom. The needle has a longitudinal axis, a sharp end, and a
central axial
passageway. A safety shield associated with the needle comprises a tubular
housing adapted
for movement relative to the needle between a stowed position in which the
tubular housing
is spaced from the sharp end of the needle and a deployed position in which
the tubular
housing covers the sharp end. A locking mechanism is adapted to releasably
lock the tubular
housing in position covering the sharp end of the needle. An unlocking
mechanism is
adapted to engage the locking mechanism to unlock the tubular housing from the
needle. An
obturator includes a shaft sized and shaped for reception in the central axial
passageway of
the needle. A reset member operatively connects to the shaft and selectively
operatively
engages the unlocking mechanism of the safety shield for moving the unlocking
mechanism
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into selective engagement with the locking mechanism for releasing the locking
mechanism
to permit the tubular housing to move away from the sharp end of the needle.
[0009] In a further aspect of the present invention, a resettable needle
safety shield
for use in selectively shielding and unshielding a sharp tip of a needle
generally comprises a
housing sized and shaped for substantially surrounding the sharp needle tip to
hinder access
to the sharp tip and a locking mechanism associated with the housing. The
locking
mechanism is adapted to lock the housing in position substantially surrounding
the sharp
needle tip. An unlocking mechanism is associated with the housing for movement
relative to
the housing between a first position in which the locking mechanism is free to
lock the
housing in position relative to the sharp needle tip and a second position in
which the
unlocking mechanism releases the locking mechanism to permit movement of the
housing
relative to the needle.
[0010] In yet a further aspect of the present invention, a needle assembly
generally
comprises a mounting structure and a needle mounted on the mounting structure
and
extending outwardly therefrom. The needle has a longitudinal axis, a sharp end
and a central
axial passageway. A safety shield is associated with the needle and comprises
a tubular
housing having an open end. The tubular housing is adapted for movement
relative to the
needle between a stowed position in which the tubular housing is spaced from
the sharp end
of the needle and a deployed position in which the tubular housing covers the
sharp end. A
locking mechanism is adapted to releasably lock the tubular housing in
position covering the
sharp end of the needle. A reset member is selectively operatively engageable
with the
locking mechanism of the safety shield for releasing the locking mechanism to
permit the
tubular housing to be move away from the sharp end of the needle. The safety
shield further
comprises a resilient membrane substantially covering the open end of the
tubular housing.
The membrane is resiliently deformable upon engagement with the reset member
to permit
the reset member to move into operative engagement with the locking mechanism
for
releasing the locking mechanism.
[0011] In another aspect of the present invention, a needle assembly generally
comprises mounting structure and a needle mounted on the mounting structure
and extending
outwardly therefrom. The needle has a longitudinal axis, a sharp end and a
central axial
passageway. A safety shield associated with the needle comprises a tubular
housing that may
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have an open end. The tubular housing is adapted for movement relative to the
needle
between a stowed position in which the tubular housing is spaced from the
sharp end of the
needle and a deployed position in which the tubular housing covers the sharp
end. A locking
mechanism is adapted to releasably lock the tubular housing in position
covering the sharp
end of the needle. A reset member supported on the safety shield for sliding
movement
relative to the safety shield generally parallel to a outer surface of the
safety shield, the resent
member being selectively operatively engageable with the locking mechanism of
the safety
shield for releasing the locking mechanism to permit the tubular housing to be
move away
from the sharp end of the needle.
[0012] Other objects and features of the present invention will be in part
apparent
and in part pointed out hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a perspective of a bone needle assembly including an
obturator;
[0014] FIG. 2 is a fragmentary partial section of the needle assembly with the
obturator engaging a safety shield of the needle assembly and parts broken
away to show
internal construction;
[0015] FIG. 3 is the fragmentary elevation of Fig. 2 but showing the obturator
inserted to a position in which a sample collected by the needle assembly is
pushed out of the
needle assembly;
[0016] FIG. 4 is the fragmentary elevation of Fig. 2 but showing use of the
obturator to reset a locking mechanism of the safety shield;
[0017] FIG. 5 is the fragmentary elevation of Fig. 2 but showing the safety
shield
being withdrawn from a sharp end of the needle assembly after release of the
locking
mechanism;
[0018] FIG. 6 is an end elevation of the obturator;
[0019] FIG. 7 is a perspective of a needle assembly of a second embodiment
including an obturator;
[0020] FIG. 8 is a fragmentary partial section of the needle assembly of Fig.
7
illustrating the obturator just prior to insertion into the needle assembly
and parts broken
away to show internal construction;
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[0021] FIG. 9 is the fragmentary partial section of Fig. 8 but showing the
obturator
inserted into the needle assembly a distance sufficient to remove a sample
from the obturator;
[0022] FIG. 10 is the fragmentary partial section of Fig. 8 but showing a
reset
feature of the obturator entering a safety shield of the needle assembly;
[0023] FIG. 11 is the fragmentary partial section of Fig. 8 but showing the
obturator resetting a locking mechanism of the safety shield to permit the
safety shield to be
withdrawn from a sharp end of the needle assembly;
[0024] FIG. 12 is a perspective of a needle assembly of a third embodiment
including an obturator;
[0025] FIG. 13 is a perspective of a modified obturator similar to that of Fig
12;
[0026] FIG. 14 is a fragmentary partial section showing the obturator of Fig.
13
inserted into the needle assembly but prior to resetting a locking mechanism
thereof with
parts broken away to show internal construction;
[0027] FIG. 15 is a perspective of an obturator of a needle assembly of a
fourth
embodiment;
[0028] FIG. 16 is a fragmentary partial section of the obturator partially
inserted
into the needle assembly with parts broken away to show internal construction;
[0029] FIG. 17 is a perspective of a bone needle assembly of a fourth
embodiment
including an obturator;
[0030] FIG. 18 is a fragmentary partial section of the needle assembly with
the
obturator entering a safety shield of the needle assembly;
[0031] FIG. 19 is the fragmentary elevation of Fig. 18 but showing the
obturator
inserted to a position in which a sample collected by the needle assembly is
pushed out of the
needle assembly;
[0032] FIG. 20 is the fragmentary elevation of Fig. 18 but showing use of the
obturator to reset a locking mechanism of the safety shield;
[0033] FIG. 21 is the fragmentary elevation of Fig. 18 but showing the safety
shield set for withdrawal from a sharp end of the needle assembly after
release of the locking
mechanism;
[0034] FIG. 22 is a fragmentary perspective of the obturator with parts broken
away to show internal construction;
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[0035] FIG. 23 is an end view of the obturator;
[0036] FIG. 24 is a fragmentary perspective of the obturator entering the
safety
shield;
[0037] FIG. 25 is a fragmentary partial section of a needle assembly of a
fifth
embodiment in a configuration similar to Fig. 19;
[0038] FIG. 26 is a fragmentary perspective of an obturator of the needle
assembly
of Fig. 25;
[0039] FIG. 27 is a fragmentary perspective of an end of a shield of the
needle
assembly of Fig. 25;
[0040] FIG. 28 is a perspective of a bone needle assembly of a sixth
embodiment
including an obturator;
[0041] FIG. 29 is a fragmentary partial section of the needle assembly with
the
obturator entering a safety shield of the needle assembly;
[0042] FIG. 30 is the fragmentary elevation of Fig. 29 but showing the
obturator
inserted to a position in which a sample collected by the needle assembly is
pushed out of the
needle assembly;
[0043] FIG. 31 is the fragmentary elevation of Fig. 29 but showing use of the
obturator to reset a locking mechanism of the safety shield;
[0044] FIG. 32 is the fragmentary elevation of Fig. 29 but showing the safety
shield being withdrawn from a sharp end of the needle assembly after release
of the locking
mechanism;
[0045] FIG. 33 is a fragmentary perspective of the obturator with parts broken
away to show internal construction;
[0046] FIG. 34 is an end view of the obturator;
[0047] FIG. 35 is a fragmentary perspective of the needle assembly showing the
safety shield;
[0048] FIG. 36 is a perspective view of an obturator of a needle assembly of a
seventh embodiment incorporating an integral funnel guide and reset feature;
[0049] FIG. 37 is a perspective view of the obturator of Fig. 36 and another
part of
the needle assembly during resettable engagement;
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[0050] FIG. 38 is the perspective of Fig. 37 with parts broken away to show
internal construction;
[0051] FIG. 39 is an enlarged fragment of the perspective of Fig. 37;
[00521 FIG. 40 is the perspective of Fig. 37 with the obturator inserted
through a
needle of the needle assembly;
[0053] FIG. 41 is the perspective of Fig. 40 with parts broken away to show
internal construction;
[0054] FIG. 42 is an enlarged fragment of the perspective of Fig. 41;
[0055] FIG. 43 is a perspective view of an obturator;
[0056] FIG. 44 is a perspective view of a funnel for guiding an obturator;
[00571 FIG. 45 is a cutaway view of a funnel placed over a needle;
[0058] FIG. 46 shows locating features on the safety shield for guiding the
obturator to the inner diameter of the needle;
[0059] FIG. 47 shows an obturator inserted into a funnel;
[0060] FIG. 48 is a perspective view of an alternative embodiment of the
medical
needle shield apparatus according to the present disclosure;
[0061] FIG. 49 is a cutaway view of the embodiment shown in Fig. 48;
[0062] FIG. 50 is an enlarged view of the safety shield of the embodiment
shown
in Fig. 48;
[0063] FIG. 51 is a cutaway view of the safety shield having a needle
inserted;
[0064] FIG. 52 is a perspective view of the safety shield having an obturator
inserted;
[0065] FIG. 53 is an enlarged perspective view of the safety shield having an
adjustable guide;
[00661 FIG. 54 is an enlarged perspective view of the safety shield having an
adjustable guide with a reset area;
[0067] FIG. 55 is a guiding member integrated with an obturator;
[0068] FIG. 56 is a guiding member integrated with an obturator having a
spring;
[0069] FIG. 57 is an enlarged view of the guiding member shown in Fig. 56;
[00701 FIG. 58 is an elevation of a guiding member integrated with an
obturator of
another embodiment just prior to mating with a cannula;
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[0071] FIG. 59 is the elevation of Fig. 58 with the obturator inserted into
the
cannula;
[0072] FIG. 60 is an obturator handle having a resettable feature;
[0073] FIG. 61 is an obturator handle having a resettable feature;
[0074] FIG. 62 is an obturator handle having a resettable feature inserted
into a
needle;
[0075] FIG. 63 is an alternative embodiment of the medical needle shield
apparatus
according to the present disclosure;
[0076] FIG. 64 is a safety shield incorporating a reset member; and
[0077] FIG. 65 is a longitudinal section of the safety shield.
[0078] Corresponding reference characters indicate corresponding parts
throughout
the several views of the drawings.
DETAILED DESCRIPTION
[0079] Referring now to the drawings and in particular to Fig. 1, a medical
instrument constructed according to the principles of the present invention is
shown in the
form of a bone needle assembly, generally indicated at 10. The bone needle
assembly
includes a handle 12 (broadly, "mounting structure"), a needle 14 and a
cannula safety shield
16, all reference numbers indicating their subjects generally. The needle 14
includes a stylet
18 and a cannula 20 that can receive the stylet. The handle 12 includes a
first or proximal
handle member (indicated generally at 22) mounting the stylet 18, and a second
or distal
handle member (indicated generally at 24) mounting the cannula 20. It will be
understood
that a needle could include only a single component part, or more than two
parts within the
scope of the present invention. Similarly, a handle could be a single part or
more than two
parts. The mounting structure for the needle 14 can be other than a handle
without departing
from the present invention. The needle assembly 10 further includes an
obturator 26
(described more fully below) that may be used to remove a sample captured in
the cannula
20.
[0080] The cannula 20 has a central axial passage extending the length of the
cannula and opening at both ends of the cannula. A distal tip 28 of the
cannula 20 is beveled
and sharpened. A proximal end portion of the cannula 20 is received in the
distal handle
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member 24. The stylet 18 is solid and includes a sharp distal tip, and a
proximal end portion
received in the proximal handle member 22. The stylet 18 can be inserted
through the axial
passage opening in the proximal end portion of the cannula 20 and received
entirely through
the axial passage of the cannula so that its sharp distal tip projects axially
outward from the
distal tip 28 of the cannula. The stylet 18 provides the tool for penetrating
the cortical bone,
and can be removed from the cannula 20 once the intramedullary canal is
accessed by the
needle 14.
[0081) The handle 12 formed by the proximal and distal handle members 22, 24
has an ergonomic shape that can be comfortably received in a medical
technician's hand, and
allows the technician to easily control the needle assembly 10 as he or she
applies the
substantial forces needed to penetrate the bone. More specifically, the top or
proximal
surface 38 of the proximal handle member 22 is rounded in conformance with the
shape of
the palm of the hand. The bottom or distal surface 40 of the distal handle
member 24 is also
rounded, but is undulating in shape thereby forming finger wells 40A for
receiving the
technician's fingers. The form of the handle can be other than described
herein without
departing from the scope of the present invention. The proximal and distal
handle members
22, 24 can be connected together in a suitable manner when the stylet 18 is
received in the
cannula 20, so that the handle 12 acts essentially as a single piece when used
to drive the
needle 14 through a patient's skin and into the bone. The proximal and distal
handle
members 22, 24 can be disconnected and moved apart for removing the stylet 18
from the
cannula 20.
[00821 The cannula safety shield 16 may be moved to cover the distal tip 28 of
the
cannula 20 after the needle assembly 10 has been used. The safety shield 16
includes a
generally tubular housing 50 and an internal locking mechanism (generally
indicated at 52 in
Fig. 2) capable of releasably locking the tubular housing in position covering
the distal tip 28
of the cannula 20. The tubular housing 50 may have any shape that is suitable
for hindering
access to the sharp tip 28. The tubular housing 50 need not be solid or
circular in cross
section within the scope of the present invention. The tubular housing 50 and
handle 12 may
include structure to secure the tubular housing in a retracted position
adjacent the handle
when not needed. An example of such structure is shown in co-assigned U.S.
application
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Serial No. 11/146,173, filed June 6, 2005, the disclosure of which is
incorporated herein by
reference.
[0083] The locking mechanism 52 inside the safety shield 16 comprises a
canting
member including a base 56 having a hole and a pair of arms 60 (only one is
shown)
extending generally axially from the base. The arms 60 are connected together
by a U-
shaped member 62 at their ends and each has an upwardly (as oriented in the
figures) bent tab
64 (only one is shown) projecting axially outward from the end. Before the
locking
mechanism 52 is activated to lock the tubular housing 50 in position, the ends
of the arms 60
ride on the exterior surface of the cannula 20. This holds the canting member
so that the base
56 is orthogonal so the longitudinal axis of the cannula 20 and the base can
move along the
cannula (with the safety shield 16), with the cannula sliding unimpeded
through the hole in
the base. Once the ends of the arms 60 pass the distal tip 28 of the cannula
20, the locking
mechanism 52 is weighted so that the ends of the arms move in a generally
radial direction
toward an opposite side of the longitudinal axis of the needle 14. This causes
the base 56 of
the canting member to cant relative to the axis of the needle 14 so that the
hole in the base is
no longer orthogonal to the axis of the cannula. As a result, the base 56 at
the edge of the
hole grippingly engages the cannula 20 to lock the safety shield 16 in place.
It will be
understood that a locking mechanism could take on other forms than shown and
described
without departing from the scope of the present invention. Moreover, the
canting member
may take on other configurations within the scope of the present invention.
[0084] The needle assembly 10 is driven into the bone by grasping the handle
12
and pushing the stylet 18 through the skin, underlying tissue and cortical
bone. Once this
penetration has been achieved, the stylet 18 is no longer required. The
proximal handle
member 22 is disconnected from the distal handle member 24 and moved axially
away from
the distal handle member so that the stylet 18 slides out of the central axial
passageway of the
cannula 20 while the cannula remains in the bone. In order to collect a sample
of bone
marrow, the distal handle member is advanced further into the bone. The sharp
tip 28 of the
cannula 20 cuts into the bone marrow and a sample is received in the central
axial
passageway of the cannula. The cannula 20 can then be withdrawn from the
patient by
pulling on the distal handle member 24. The sample remains lodged in the
central axial
passageway of the cannula 20 near the sharp tip 28. It will be understood that
a needle
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assembly may be used to collect a sample other than of bone marrow within the
scope of the
present invention.
[00851 The obturator 26 is used to remove a lodged sample of bone marrow that
has been collected in the central axial passageway of cannula 20. The
obturator 26 includes a
grip 68 and a long, thin shaft 70 extending from the grip that is sized to be
received in the
central axial passageway of the cannula 20 in generally close fitting relation
therein. The grip
68 is sized and shaped to be grasped by a user for manipulating the obturator
26, as will be
described. A tubular reset member 72 extends from the grip 68 in the same
direction as the
shaft 70 and is generally coaxial with the shaft in the illustrated
embodiment. The reset
member 72 has an open end 73 opposite the grip 68. A coil compression spring
74 surrounds
the reset member 72 and is operatively secured to the grip 68. An annular
aligning device in
the form of a cap 76 is slidably mounted on the free end of the shaft 70
(opposite the grip 68),
and is capable of centering the shaft relative to the tubular housing 50. In
one version (not
shown) the cap 76 may be attached to the spring 74 for use in retaining the
cap on the
obturator 26. The cap 76 has an opening 78 having an annular, resilient
membrane that can
engage and center the shaft 70 in the opening. As shown in Fig. 2, the cap
receives a distal
end portion of the tubular housing 50 in generally close-fitting relation so
that the shaft 70 of
the obturator 26 is aligned with the central axial passageway of the cannula
20. The cap 76
and tubular housing 50 may be formed so that the cap has a releasable, snap-
acting
attachment with the housing when engaging the housing. However, the attachment
may be
omitted or take on other forms without departing from the scope of the present
invention.
[0086] Figure 2 illustrates the initial position of the obturator 26 with the
cap 76
engaging the proximal end of the tubular housing 50. The free end of the shaft
70 has not yet
entered the central axial passageway of the cannula 20. The grip 68 is pushed
to advance the
shaft 70 into the central axial passageway, which pushes the sample toward the
proximal end
of the central axial passageway. As shown in Fig. 3, the shaft 70 is advanced
until it
protrudes out of the proximal end of the central axial passageway, thereby
pushing the
sample (not shown) out of the cannula 20 where it can be collected in a Petri
dish or other
suitable container. As the shaft 70 is advanced, it slides through the cap 76.
The locking
mechanism 52 remains engaged so that the safety shield 16 does not move. In
the position
shown in Fig. 3, the spring 74 surrounding the reset member 72 engages the cap
76, but is not
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substantially deflected by this engagement. Thus, the technician experiences
slight resistance
to further inward movement of the shaft 70 into the central axial passageway
of the cannula
20.
[00871 The technician may observe the sample ejected from the central axial
passageway of the cannula 20. If it is determined that the sample is
satisfactory, the obturator
26 can be pulled so that the shaft 70 slides back through and out of the
cannula 20. The
needle assembly 10 can be discarded, or possibly but less likely, cleaned and
sterilized for a
subsequent use. However, if the sample is not satisfactory it will be
necessary to obtain a
second sample. This can be done using the same needle assembly 10, but the
tubular housing
50 is locked in place by the locking mechanism 52 over the sharp tip 28 of the
cannula 20.
The tubular housing 50 needs to be moved away from the tip 28 before the
needle assembly
can be used to obtain a second sample.
[00881 The obturator 26 of the present invention is particularly adapted to
permit
the tubular housing 50 to be released and moved back from the sharp tip 28 of
the cannula 20.
From the position shown in Fig. 3, the grip 68 can be advanced toward the
tubular housing 50
against the bias of the spring 74 so that the reset member 72 is received into
the tubular
housing and engages the locking mechanism 52. More particularly, the tabs 64
of the canting
member engage a leading free edge portion 80 of the reset member 72 so that
the reset
member wedges the canting member up to a position in which the base is again
substantially
orthogonal to the axis of the cannula 20, as shown in phantom in Fig. 4. The
open end 73 can
receive a portion of the cannula 20 to allow the reset member 72 to be
advanced far enough to
reset the locking mechanism 52. Movement of the canting member in this manner
positions
the hole in the base 56 so that the cannula 20 can slide easily through the
canting member.
Thus as shown in Fig. 5, the tubular housing 50 can be grasped to pull back
the safety shield
16 toward the distal housing member 24 so that the sharp tip 28 of the cannula
20 is once
again exposed. The obturator shaft 70 can be removed and the stylet 18 can be
reinserted into
the cannula 20 for a second collection of a sample. It will be appreciated
that the spring 74
inhibits the accidental release of the locking mechanism 52. The technician
must
intentionally overcome the resisting bias of the spring to de-activate the
locking mechanism
52.
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100891 Referring now to Figs. 7-11, a needle assembly 110 of a second
embodiment is shown to comprise a handle 112 and a needle 114 extending from
the handle.
A cannula safety shield 116 received on the cannula 120 can be slid down to
cover the sharp
tip 128 of the cannula. The construction and operation of the handle 112 and
needle 114 are
substantially the same as for the handle 112 and needle 114 of the needle
assembly 110 of the
first embodiment. The same reference characters will be used to indicate
corresponding parts
of the needle assembly 110 of the second embodiment, plus "100". Moreover, the
handle 112
and needle 114 will not be further described in view of their similarity to
the first
embodiment. The safety shield 116 includes a tubular housing 150 and a locking
mechanism
152. The locking mechanism 152 may be substantially the same as the locking
mechanism
152 of the first embodiment. The tubular housing 150 is similar to the tubular
housing 150 of
the first embodiment. However, a proximal end of the tubular housing 150 would
be open
except for an annular, flexible membrane 151 (broadly, "an aligning device")
that covers the
open end. The membrane 151 has a central aperture 153 that is aligned with the
proximal
opening of the central axial passageway in the cannula 120. The membrane 151
is used to
guide an obturator 126 into the central axial passageway, as will be
described.
[0090] The obturator 126 comprises a grip 168 and a long, thin shaft 170
extending
from the grip and sized for being received in the central axial passageway of
the cannula 120.
The obturator 126 further includes a tubular reset member 172 projecting from
the grip 168
and surrounding the portion of the shaft 170 adjacent to the grip. The
construction of the
obturator 126 is similar to the obturator 126 of the first embodiment, except
that there is no
spring 174 or annular cap 176.
[0091] Figures 8-11 illustrate the operation of the obturator 126 of the
second
embodiment to remove a bone marrow sample (not shown) from the central axial
passageway
of the cannula 120 and, if desired, to de-activate the locking mechanism 152
of the safety
shield 116 to permit the shield to be withdrawn from the sharp tip 128 of the
cannula to reset
the needle assembly 110 for a second use. As shown in Fig. 8, the medical
technician aligns
the shaft 170 with the aperture 153 in the membrane 151 of the safety shield
116, which
results in the shaft also being aligned with the central axial passageway of
the cannula 120.
The shaft 170 is then inserted through the aperture 153 and into the central
axial passageway,
as shown in Fig. 9. It will be appreciated that the membrane 151 engages the
shaft 170 when
CA 02595683 2009-01-16
the shaft is inserted into the aperture 153 and thereby operates to guide the
shaft into the
central axial passageway. However, other structure for guiding the obturator
shaft 170 may
be provided, or guiding structure may be entirely omitted without departing
from the scope of
the present invention. The shaft 170 is sized in length so that at about the
same time as a
leading edge portion 180 of the reset member 172 engages the membrane 151, or
slightly
before, the shaft will have passed completely through the cannula 120 and
project out the
proximal end thereof. The sample (not shown) will have been ejected from the
cannula 120
at this point. The reset member 172 may engage the membrane 151, which
provides a slight
resistance to further advancement of the shaft 170 into the safety shield 116
and central axial
passageway of the cannula 120. This signals to the operator that the obturator
126 has been
pushed far enough into the cannula 120.
[00921 If the sample is satisfactory, the obturator 126 can be withdrawn from
the
cannula 120 and tubular housing 150, and the needle assembly 110 discarded.
However, if a
second bone marrow sample needs to be taken, the obturator 126 can be advanced
from the
position shown in Fig. 9 further into the safety shield 116. As shown in Fig.
10, the reset
member 172 deflects and stretches the membrane 151, causing the aperture 153
to enlarge to
the extent that the reset member 172 is admitted into the tubular housing 150
through the
aperture. The reset member 172 is the only part of the obturator shown in
section in Fig. 10.
The reset member 172 continues to advance to the position in Fig. 11. As the
reset member
172 advances, the leading edge portion 180 engages the tabs 164 of the locking
mechanism
152 pushing the locking mechanism back to its position where the safety shield
116 is free to
slide along the cannula 120. Thus in substantially the same was as shown in
Fig. 5, the
tubular housing 150 can be grasped and moved proximally away from the sharp
tip 128 of the
cannula 120 to ready the needle assembly 110 for a second use.
[00931 A needle assembly 210 of a third embodiment is shown in Fig. 12. Parts
of
the needle assembly 210 of the third embodiment are indicated by the same
reference
numerals as for the needle assembly 210 of the first embodiment, plus "200".
The obturator
226 includes a grip 268 having a generally tubular portion 269 that extends
along the shaft
270 to a distance which fully surrounds the reset member 272. The cross
section of an
opening 273 defined by the tubular portion 269 of the grip 268 is elliptical
(or otherwise not
the same shape as the cross section of the tubular housing 250). The shaft 270
may be
CA 02595683 2009-01-16
16
inserted into the tubular housing 250 and central axial passageway of the
cannula 220 as
before. However when the grip 268 reaches the tubular housing 250, it engages
the tubular
housing because the elliptical cross sectional shape of the opening 273 does
not match the
circular cross sectional shape of the tubular housing. This prevents the reset
member 272
from being inadvertently inserted into the tubular housing 250 resulting in an
unintended
release of the locking mechanism 252 which could cause the contaminated sharp
tip 228 of
the cannula 220 to be exposed when the obturator 226 is removed from the
central axial
passageway.
[0094] If it is necessary to de-activate the locking mechanism 252 and
withdraw
the safety shield 216 from the sharp tip (not shown) of the cannula 220, the
obturator 226 can
be reconfigured so that the reset member 272 can move into the tubular housing
250. This
can be accomplished by squeezing on opposite sides of the grip 268, such as
indicated by the
arrows in Fig. 12. For instance, the points at which the grip 268 is engaged
for squeezing
may be the opposite ends of the major axis of the ellipse. The grip 268 is
formed of an elastic
and resilient material that allows the elliptical shape of the opening 273 to
become more
nearly circular to match the shape of the tubular housing 250. Once the shapes
are matched,
the grip 268 and reset member 272 can be advanced, with the grip receiving the
tubular
housing 250 therein and the tubular housing receiving the reset member 272.
The reset
member operates to de-activate the locking mechanism 252 in the same way as
described
previously herein.
[0095] Referring now to Figs. 13 and 14, a modified obturator 226' of the
second
embodiment is shown. The same reference numerals as used for the needle
assembly 210 of
the third embodiment will be used to indicate corresponding parts in the
modified version,
with the addition of a trailing prime. It is noted that the tubular housing
250' of the safety
shield 216' does not include the membrane 151 of the second embodiment, but
otherwise may
be of the same construction. However, a membrane (not shown) could be employed
in this
modified version. The principle of operation is similar to the third
embodiment. More
specifically the grip 268' includes a circular base 268a' from which two
projecting members
269' extend a distance greater than the axial extent of the reset member 272'.
The projecting
members 269' at their free ends are spaced apart across an opening 273' a
distance less than
the diameter of the tubular housing 250', but are not sized to fit inside the
tubular housing.
CA 02595683 2009-01-16
17
Accordingly when the obturator shaft 270' is inserted into the central axial
passageway of the
cannula 220' a distance which brings the grip 268' into engagement with the
tubular housing
250', the free ends of the projecting members 269' engage the tubular housing
and prevent
further advancement. Thus, the reset member 272' remains outside the tubular
housing 250'
and the locking mechanism 252' is not inadvertently de-activated.
[0096] To allow the locking mechanism 252' to be de-activated and the safety
shield 216' withdrawn from the sharp tip of the cannula 220, the grip 268' is
provided with
wings 273', each projecting outward from the base 268a' adjacent to a
respective one of the
projecting members 269'. The wings extend generally in the opposite direction
from the base
268a' as the projecting members 269, but also extend radially outward so that
the wings 273'
diverge from each other. The wings 273' can be gripped and squeezed as
indicated in Fig. 14
so that the free ends of the projecting members 269' move apart from each
other. The base
268a' acts as the fulcrum about which the projecting members 269' pivot. This
movement
allows the projecting members 269' to receive the tubular housing 250' between
them. The
reset member 272' can be advanced into the tubular housing 250' to de-activate
the locking
mechanism 252' as described previously herein.
[0097] Referring now to Figs. 15 and 16, a needle assembly 310 of a fourth
embodiment includes component parts that are indicated by the same reference
numerals as
used for the needle assembly 310 of the first embodiment, plus "300". The
needle 314 and
safety shield 316 shown in Fig. 16 may have the same construction and
operation as the
corresponding parts in the embodiment shown in Fig. 14. The obturator 326 of
the fourth
embodiment includes a grip 368 and a hollow cylindrical portion 375 extending
axially from
the grip. The reset member 372 is located on the axially opposite side of the
hollow portion
375 from the grip 368. A hole 377 in the hollow portion 375 allows its
interior to
communicate with the interior of the tubular reset member 372. The shaft 370
includes an
obstruction 379 positioned adjacent the free edge portion 380 of the reset
member 372. The
shaft 370 extends through the reset member 372 and the hole 377 into the
hollow portion 375.
The end of the shaft 370 is formed with an indicator plaque 381 that is wider
than the hole
377 in the hollow portion 375 so that the shaft 370 may not be withdrawn from
the hollow
portion. It will be understood that the plaque 381 may have other shapes
(e.g., cylindrical
with a larger diameter than the hole 377) without departing from the scope of
the present
CA 02595683 2009-01-16
18
invention. The shaft 370 may be moved axially relative to the reset member 372
and hollow
portion 375. A coil compression spring 374 is located in the tubular reset
member 372. The
spring bears against a wall around the hole 377 that separates the interior of
the reset member
372 from the interior of the hollow portion 375. The other end of the spring
374 bears
against the obstruction 379 on the shaft 370. Thus, the spring 374 biases the
shaft 370 axially
outwardly from the grip 368, hollow portion 375 and reset member 372.
[00981 The hollow portion 375 includes a window 383 defined in the hollow
portion 375 that is transparent or translucent. The window could be formed
simply by an
opening in the hollow portion. The other parts of the hollow portion 375 are
opaque. Thus,
when the plaque 381 is in the position shown in solid lines in Fig. 16, it
cannot be seen
through the window 383. However as will be described, the shaft 370 can be
moved to bring
the plaque 381 into registration with the window 383 so that the plaque is
visible through the
window. The plaque 381 may be colored to increase its visibility.
[00991 In operation to remove a bone marrow sample from the cannula 320, the
shaft 370 is aligned with the central axial passage of the cannula and
inserted. Although no
alignment device is shown, a cap like the cap 376 shown in Fig. 1, a membrane
like the
membrane 151 shown in Fig. 8, or some other suitable aligning device can be
used to assist
getting the shaft 370 inside the central axial passageway can be used. The
shaft 370 can be
easily advanced through the central axial passageway of the cannula 320 until
the obstruction
379 engages the distal end of the cannula. The obstruction 379 is too large to
fit into the
central axial passageway and so resistance to further advancement of the shaft
370 into the
cannula 320 is felt by the medical technician. The shaft 370 is sized so that
at this point the
shaft extends completely through the cannula 320 and the sample (not shown)
will have been
ejected.
[001001 If it is necessary to reset the needle assembly 310 for collecting
another
bone marrow sample, then the obturator 326 can be advanced against the bias of
the spring
374. This allows the reset member 372 to enter the tubular housing 350 of the
safety shield
316 for engaging the locking mechanism 352 to de-activate it as described
previously.
However, the shaft 370 remains stationary relative to the cannula 320 because
of the
engagement of the obstruction 379 with the cannula. This causes the plaque 381
to move
relative to the hollow portion 375 so that it is brought into registration
with the window 383
CA 02595683 2009-01-16
19
(shown in phantom in Fig. 16). The appearance of the plaque 381 indicates that
the reset
member 372 has been inserted far enough to de-activate the locking mechanism
352. The
technician is given visual confirmation that de-activation has occurred so
that he or she
knows that the safety shield 316 can be withdrawn (i.e., substantially as
shown in Fig. 5). It
will be understood that other ways of confirming de-activation of the locking
mechanism 352
can be used within the scope of the present invention.
[00101] Referring now to Figs. 17-24, a medical instrument constructed
according to
the principles of the present invention is shown in the form of a bone needle
assembly,
generally indicated at 410 (see, Fig. 17). The bone needle assembly includes a
handle 412
(broadly, "mounting structure"), a needle 414 and a cannula safety shield 416,
all reference
numbers indicating their subjects generally. The needle 414 includes a stylet
418 and a
cannula 420 that can receive the stylet. The handle 412 includes a first or
proximal handle
member (indicated generally at 422) mounting the stylet 418, and a second or
distal handle
member (indicated generally at 424) mounting the cannula 420. It will be
understood that a
needle could include only a single component part, or more than two parts
within the scope of
the present invention. Similarly, a handle could be a single part or more than
two parts. The
mounting structure for a needle can be other than a handle without departing
from the present
invention. The needle assembly 410 further includes an obturator 426, which is
described
more fully below, that may be used to remove a sample captured in the cannula
420.
[00102] The cannula 420 has a central axial passage extending the length of
the
cannula and opening at both ends of the cannula. A distal tip 428 of the
cannula 420 is
beveled and sharpened, and a proximal end portion of the cannula 420 is
received in the distal
handle member 424. The stylet 418 is solid and includes a sharp distal tip,
and a proximal
end portion of the stylet is received in the proximal handle member 422. The
stylet 418 can
be inserted through the central axial passage opening in the proximal end
portion of the
cannula 420 and received entirely through the axial passage of the cannula so
that its sharp
distal tip projects axially outward from the distal tip 428 of the cannula (as
shown in Fig. 17).
The stylet 418 provides the tool for penetrating the cortical bone, and can be
removed from
the cannula 420 once the intramedullary canal is accessed by the needle 414.
[00103] The handle 412 formed by the proximal and distal handle members 422,
424 has an ergonomic shape that can be comfortably received in a medical
technician's hand,
CA 02595683 2009-01-16
and allows the technician to easily control the needle assembly 410 as he or
she applies the
substantial forces needed to penetrate the bone. More specifically, the top or
proximal
surface 438 of the proximal handle member 422 is rounded in conformance with
the shape of
the palm of the hand. The bottom or distal surface 440 of the distal handle
member 424 is
also rounded, but is undulating in shape thereby forming finger wells 442 for
receiving the
technician's fingers. The form of the handle can be other than described
herein without
departing from the scope of the present invention. Moreover, needle mounting
structure can
be other than a handle within the scope of the present invention. The proximal
and distal
handle members 422, 424 can be connected together in a suitable manner when
the stylet 18
is received in the cannula 420, so that the handle 412 acts essentially as a
single piece when
used to drive the needle 414 through a patient's skin and into the bone. The
proximal and
distal handle members 422, 424 can be disconnected and moved apart for
removing the stylet
418 from the cannula 420.
[001041 The cannula safety shield 416 may be moved to cover the distal tip 428
of
the cannula 420 after the needle assembly 410 has been used. The safety shield
416 includes
a generally tubular housing 450 and an internal locking mechanism (generally
indicated at
452 in Fig. 18) capable of releasably locking the tubular housing in position
covering the
distal tip 428 of the cannula 420. The tubular housing 450 has a proximal end
closer to the
handle 412 and a distal end farther away from the handle. A distal end piece
of the tubular
housing 450 (generally indicated at 454) includes a funnel-shaped distal end
surface 456 of
the tubular housing 450 and a central aperture 458 generally aligned with the
central axial
passageway of the cannula 420. Although illustrated as a separately formed
part attached to
the tubular housing 450, the distal end piece 454 and tubular housing may be
formed as a
single piece of material. The shape of the distal end surface 456 may be other
than described
(e.g., lying in a plane perpendicular to the longitudinal axis of the cannula
420) within the
scope of the present invention. Three slots 460 located on the periphery of
the tubular
housing distal end piece 454 each extend radially inwardly from the periphery
of the end
piece at its distal end and also extend axially along the end piece toward the
proximal end of
the tubular housing 450. The number of slots and their precise configuration
may be other
than described without departing from the scope of the present invention. The
function of the
slots 460 will be described hereinafter. The tubular housing 450 and handle
412 may include
CA 02595683 2009-01-16
21
structure to secure the tubular housing in a retracted position adjacent the
handle when not
needed. An example of such structure is shown in co-assigned U.S. application
Serial No.
11/146,173, filed June 6, 2005, the disclosure of which is incorporated herein
by reference.
[00105] The locking mechanism 452 inside the safety shield 416 comprises a
canting member including a base 462 having a hole and a pair of arms 464 (only
one is
shown) extending generally axially from the base. The arms 464 are connected
together by a
U-shaped member 466 at their ends and each has an upwardly (as oriented in the
figures) bent
tab 468 (only one is shown) projecting axially outward from the end. Before
the locking
mechanism 452 is activated to lock the tubular housing 450 in position, the
ends of the arms
464 ride on the exterior surface of the cannula 420. This holds the canting
member so that
the base 462 is generally orthogonal so the longitudinal axis of the cannula
420 and the base
can move along the cannula (with the safety shield 416), with the cannula
sliding
substantially unimpeded through the hole in the base. Once the ends of the
arms 464 pass the
distal tip 428 of the cannula 420, the locking mechanism 452 is constructed so
that the ends
of the arms move in a generally radial direction toward an opposite side of
the longitudinal
axis of the cannula 420. This causes the base 462 of the canting member to
cant relative to
the axis of the cannula 420 so that the hole in the base is no longer
orthogonal to the axis of
the cannula. As a result, the base 462 at the edge of the hole grippingly
engages the cannula
420 to lock the safety shield 416 in place. The locking mechanism 452 further
includes
angled surfaces 469A, 469B fixed to the tubular housing 450 that can engage
the canting
member base 462 to keep the canting member in its canted, locking position
upon movement
of the tubular housing 450 in either direction relative to the cannula 420. It
will be
understood that a locking mechanism could take on other forms than shown and
described
without departing from the scope of the present invention.
[00106] The safety shield 416 further includes an annular reset plunger 470
located
inside the tubular housing 450 near its distal end. The reset plunger 470 is
movable axially
relative to the housing 450 toward the proximal end and includes a
frustoconically shaped
front surface 472 that is engageable with the tabs 468 of the locking
mechanism to release the
locking mechanism, as will be more fully described hereinafter. A spring 474
engages the
reset plunger 470 and biases it toward the distal end of the tubular housing
450. Thus, unless
CA 02595683 2009-01-16
22
the reset plunger 470 is forcibly moved, it normally does not interfere with
the operation of
the locking mechanism 452.
[001071 The needle assembly 410 is driven into the bone by grasping the handle
412
and pushing the stylet 418 through the skin, underlying tissue and cortical
bone. Once this
penetration has been achieved, the stylet 418 is no longer required. The
proximal handle
member 422 is disconnected from the distal handle member 424 and moved axially
away
from the distal handle member so that the stylet 418 slides out of the central
axial passageway
of the cannula 420 while the cannula remains in the bone. In order to collect
a sample of
bone marrow, the distal handle member 424 is advanced further into the bone.
The sharp tip
428 of the cannula 420 cuts into the bone marrow and a sample is received in
the central axial
passageway of the cannula. The cannula 420 can then be withdrawn from the
patient by
pulling on the distal handle member 424. The sample remains lodged in the
central axial
passageway of the cannula 420 near the sharp tip 428. It will be understood
that a needle
assembly may be used to collect a sample other than of bone marrow within the
scope of the
present invention. Moreover, it is not necessary that a cannula be used to
collect any sample.
For instance, the cannula could also be used to withdraw or infuse fluid.
[001081 The obturator 426 is used to remove a lodged sample of bone marrow
that
has been collected in the central axial passageway of cannula 420. The
obturator 426
includes a grip 478 and a long, thin shaft 480 extending from the grip that is
sized to be
received in the central axial passageway of the cannula 420 in generally close
fitting relation
therein. The grip 478 is sized and shaped to be grasped by a user (e.g.,
between the thumb
and pointer finger) for manipulating the obturator 426, as will be described.
As shown best in
Figs. 22 and 23, a reset key, generally indicated 482, extends from the grip
478 in the same
direction as the shaft 480, and as illustrated is formed as one piece of
material with the grip.
In the illustrated fourth embodiment, the reset key 482 (broadly, "a reset
member") comprises
a tubular shroud 484 (broadly, "a support") defining a central open space 486
sized and
shaped to receive a portion of the tubular housing 450 therein. Although shown
as a solid
tubular piece of material with an open end, the shroud 484 need not be solid
around its
circumference within the scope of the present invention. Three elongate ribs
488 formed on
an inner wall 490 of the tubular shroud 484 extend generally parallel to the
axis of the shroud
and are arranged for reception in the slots 60 of the tubular housing 450 as
will be described.
CA 02595683 2009-01-16
23
It will be appreciated that a reset key (not shown) may not be part of an
obturator (i.e., the
reset key would not include a shaft like shaft 480) without departing from the
scope of the
present invention.
[00109] Figure 18 illustrates the initial position of the obturator 426 with
the shaft
480 entering the distal end of the tubular housing 450. The free end of the
shaft 480 has not
yet entered the central axial passageway of the cannula 420 or the aperture
458 of the distal
end piece 454. The funnel-shaped surface 456 of the distal end piece 454
guides the shaft
480 toward the aperture 458 that is aligned with the central axial passageway
of the cannula
420, thereby facilitating reception of the shaft in the passageway. The grip
478 is pushed to
advance the shaft 480 through the aperture 458 in the funnel-shaped surface
456 and into the
central axial passageway, which pushes the sample toward the proximal end of
the central
axial passageway. The shaft 480 is advanced until it protrudes out of the
proximal end of the
central axial passageway, thereby pushing the sample (not shown) out of the
cannula 420
where it can be collected in a Petri dish or other suitable container. The
relative location of
the tubular shroud 484 and safety shield 416 are in this position are
illustrated in Fig. 19. As
the shaft 480 is advanced, it slides through the aperture 458 in the distal
end piece 454. The
locking mechanism 452 remains engaged so that the safety shield 416 does not
move and the
sharp tip 428 remains covered.
[00110] The technician may observe the sample ejected from the central axial
passageway of the cannula 420. If it is determined that the sample is
satisfactory, the
obturator 426 can be pulled so that the shaft 480 slides back through and out
of the cannula
420. The needle assembly 410 can be discarded, or possibly but less likely,
cleaned and
sterilized for a subsequent use. If the sample is not satisfactory, however,
it will be necessary
to obtain a second sample from the same patient. This can be done using the
same needle
assembly 410, but the tubular housing 450 is locked in place by the locking
mechanism 452
over the sharp tip 428 of the cannula 420. The tubular housing 450 needs to be
moved away
from the tip 428 before the needle assembly 410 can be used to obtain a second
sample.
[00111] The obturator 426 of the present invention is particularly adapted to
permit
the safety shield 416 to be released and moved back from the sharp tip 428 of
the cannula
420. It should be understood, however, that a device other than an obturator
426
incorporating the resetting, or unlocking, features of the obturator described
herein, but not
CA 02595683 2009-01-16
24
functioning as an obturator, is also contemplated as within the scope of the
present invention.
From the position shown in Fig. 19, the grip 478 can be advanced toward the
tubular housing
450 so that the ribs 488 are received into the corresponding peripheral slots
460 in the tubular
housing 450. It will be necessary to align the ribs 488 with corresponding
ones of the slots
460 before the ribs may enter the slots. The slots 460 and ribs 488 maybe
shaped and/or
arranged to make this easier or harder to accomplish as desired. In the
illustrated
embodiment, the three slots 460 and three ribs 488 are all the same size and
shape and located
at 120 degree intervals. This arrangement makes it relatively easy to align
the obturator 426
and safety shield 416 so that the ribs 488 will be received in the slots 460.
However, as
stated previously, other arrangements and configurations are envisioned. For
example and
without limiting the breadth of the present disclosure, the slots 460 and ribs
488 can be
arranged at unequal intervals. Moreover, the slots 460 and ribs 488 may have
different sizes
so that the ribs will be received in the slots in only one relative
orientation of the obturator
426 and the safety shield 416. Those of ordinary skill in the art will
appreciate other possible
configurations and/or arrangements. The bias of the spring 474 resists further
advancement
of the ribs 488 and hence of the obturator 426. This provides a tactile signal
to the technician
that the obturator shaft 480 has been inserted far enough into the central
axial passageway of
the cannula 420 to remove the sample, and that further insertion will result
in release of the
locking mechanism 452.
[00112] If the safety shield 416 is to be reset to expose the sharp tip 428 of
the
cannula 428, the grip 478 can be advanced toward the tubular housing 450 so
that the ribs
488 move into the slots 460 and push the reset plunger 470 against the bias of
the spring 474
axially toward the proximal end of the tubular housing 450. The front surface
472 of the
reset plunger 470 engages the tabs 468 of the canting member moving the arms
464 back to a
position more nearly parallel to the longitudinal axis of the cannula 420.
This moves the base
462 of the canting member to a position substantially orthogonal to the
longitudinal axis of
the cannula 420 so that the cannula can once again slide freely through the
hole in the base
(Fig. 20). The locking mechanism 452 is thereby released. Thus as shown in
Fig. 21, the
tubular housing 450 can be grasped to pull back the safety shield 416 toward
the distal
housing member 424 so that the sharp tip 428 of the cannula 420 is once again
exposed. The
obturator shaft 480 can be removed and the stylet 418 can be reinserted into
the cannula 420
CA 02595683 2009-01-16
for a second collection of a sample. When the ribs 488 move back out of the
slots 460, the
spring 474 moves the reset plunger 470 back toward the distal end of the
tubular housing 450
so that the locking mechanism 452 is again free to operate for locking the
safety shield 416
over the sharp tip 428 of the cannula 420.
[00113] Referring now to Figs. 25 and 26, a needle assembly of a fifth
embodiment
is shown. Parts of the needle assembly of the fifth embodiment are given the
same reference
numerals as the corresponding parts of the needle assembly of the fourth
embodiment, plus
"100". A safety shield 516 may have substantially the same construction as the
safety shield
516. In particular, the shield 516 includes a tubular housing 550 having
peripheral slots 560,
as in the fourth embodiment. An obturator 526 and reset key 582 also have
similar
constructions (e.g., including ribs 588) as in the fourth embodiment. However,
a tubular
shroud 584 of the fifth embodiment has a length which is sufficiently great so
that a central
open space 586 of the shroud can receive substantially the entire tubular
housing 550.
Preferably at least a majority of the tubular housing 550 is received in the
open space 586 of
the shroud 584. The operation of ribs 588 associated with the tubular shroud
584 to release a
locking mechanism 552 may be as described for the fourth embodiment. However
by
receiving tubular housing 550 in the central open space 586 of the shroud 584,
the tubular
housing is shielded from being inadvertently grasped as the obturator is
pulled away from the
safety shield so that the safety shield 516 is not unintentionally pulled off
of the cannula 520,
or otherwise prematurely removed from the needle. As best seen in Fig. 27, the
peripheral
edge of a distal end piece 554 of the tubular housing 550 is shaped to include
edge segments
592 arranged at converging angles to funnel the ribs 588 into the slots 560
when the ribs
engage the distal end piece. Because the ribs 588 are located deep inside the
tubular shroud
584 at the bottom of the open space 586, alignment of the ribs with the slots
560 could be
difficult. However, the shaped peripheral edge segments 592 engage the ribs
588 and urge
the rotation of the obturator 526 to properly orient the reset key 582 so that
the ribs move into
the slots 560.
[00114] Referring now to Figs. 28-35, a medical instrument of a sixth
embodiment
is shown in the form of a bone needle assembly, generally indicated at 610
(Fig. 28). The
bone needle assembly includes a handle 612 (broadly, "mounting structure"), a
needle 614
and a cannula safety shield 616, all reference numbers indicating their
subjects generally.
CA 02595683 2009-01-16
26
The needle 614 includes a stylet 618 and a cannula 620 that can receive the
stylet. The
handle 612 includes a first or proximal handle member (indicated generally at
622) mounting
the stylet 618, and a second or distal handle member (indicated generally at
624) mounting
the cannula 620. It will be understood that a needle could include only a
single component
part, or more than two parts within the scope of the present invention.
Similarly, a handle
could be a single part or more than two parts. The mounting structure for the
needle 614 can
be other than a handle without departing from the present invention. The
needle assembly
610 further includes an obturator 626, which is described more fully below,
that may be used
to remove a sample captured in the cannula 620.
[00115] The cannula 620 has a central axial passage extending the length of
the
cannula and opening at both ends of the cannula. A distal tip 628 of the
cannula 620 is
beveled and sharpened. A proximal end portion of the cannula 620 is received
in the distal
handle member 624. The stylet 618 is solid and includes a sharp distal tip,
and a proximal
end portion of the stylet is received in the proximal handle member 622. The
stylet 618 can
be inserted through the axial passage opening in the proximal end portion of
the cannula 620
and received entirely through the axial passage of the cannula so that its
sharp distal tip
projects axially outward from the distal tip 628 of the cannula. The stylet
618 provides the
tool for penetrating the cortical bone, and can be removed from the cannula
620 once the
intramedullary canal is accessed by the needle 614.
[00116] The handle 612 formed by the proximal and distal handle members 622,
624 has an ergonomic shape that can be comfortably received in a medical
technician's hand,
and allows the technician to easily control the needle assembly 610 as he or
she applies the
substantial forces needed to penetrate the bone. More specifically, the top or
proximal
surface 638 of the proximal handle member 622 is rounded in conformance with
the shape of
the palm of the hand. The bottom or distal surface 640 of the distal handle
member 624 is
also rounded, but is undulating in shape thereby forming finger wells 640A for
receiving the
technician's fingers. The form of the handle can be other than described
herein without
departing from the scope of the present invention. The proximal and distal
handle members
622, 624 can be connected together in a suitable manner when the stylet 618 is
received in the
cannula 620, so that the handle 612 acts essentially as a single piece when
used to drive the
needle 614 through a patient's skin and into the bone. The proximal and distal
handle
CA 02595683 2009-01-16
27
members 622, 624 can be disconnected and moved apart for removing the stylet
618 from the
cannula 620.
[001171 The cannula safety shield 616 may be moved to cover the distal tip 628
of
the cannula 620 after the needle assembly 610 has been used. The safety shield
616 includes
a generally tubular housing 650 and an internal locking mechanism (generally
indicated at
652 in Fig. 29) capable of releasably locking the tubular housing in position
covering the
distal tip 628 of the cannula 620. As shown best in Fig. 635, the distal end
of the tubular
housing 650 includes a funnel-shaped guide 653 leading to an opening 654
directed toward
the central axial passageway of the cannula 620. The tubular housing 650 may
have any
shape that is suitable for hindering access to the sharp tip 628. The tubular
housing 650 need
not be solid or circular in cross section within the scope of the present
invention. The tubular
housing 650 and handle 612 may include structure to secure the tubular housing
in a retracted
position adjacent the handle when not needed. An example of such structure is
shown in co-
assigned U.S. application Serial No. 11/146,173, filed June 6, 2005, the
disclosure of which
is incorporated herein by reference.
[00118] The locking mechanism 652 inside the safety shield 616 comprises a
canting member including a base 656 having a hole and a pair of arms 660 (only
one is
shown) extending generally axially from the base. The arms 660 are connected
together by a
U-shaped member 662 at their ends and each has an upwardly (as oriented in the
figures) bent
tab 664 (only one is shown) projecting axially outward from the end. Before
the locking
mechanism 652 is activated to lock the tubular housing 650 in position, the
ends of the arms
660 ride on the exterior surface of the cannula 620. This holds the canting
member so that
the base 656 is orthogonal so the longitudinal axis of the cannula 620 and the
base can move
along the cannula (with the safety shield 616), with the cannula sliding
unimpeded through
the hole in the base. Once the ends of the arms 660 pass the distal tip 628 of
the cannula 620,
the locking mechanism 652 is weighted so that the ends of the arms move in a
generally
radial direction toward an opposite side of the longitudinal axis of the
needle 614. This
causes the base 656 of the canting member to cant relative to the axis of the
needle 614 so
that the hole in the base is no longer orthogonal to the axis of the cannula.
As a result, the
base 656 at the edge of the hole grippingly engages the cannula 620 to lock
the safety shield
616 in place. It will be understood that a locking mechanism could take on
other forms than
CA 02595683 2009-01-16
28
shown and described without departing from the scope of the present invention.
Moreover, a
canting member may take on other configurations (e.g., having only a single
arm) within the
scope of the present invention.
[00119] The needle assembly 610 is driven into the bone by grasping the handle
12
and pushing the stylet 618 through the skin, underlying tissue and cortical
bone. Once this
penetration has been achieved, the stylet 618 is no longer required. The
proximal handle
member 622 is disconnected from the distal handle member 624 and moved axially
away
from the distal handle member so that the stylet 618 slides out of the central
axial passageway
of the cannula 620 while the cannula remains in the bone. In order to collect
a sample of
bone marrow, the distal handle member is advanced further into the bone. The
sharp tip 628
of the cannula 620 cuts into the bone marrow and a sample is received in the
central axial
passageway of the cannula. The cannula 620 can then be withdrawn from the
patient by
pulling on the distal handle member 624. The sample remains lodged in the
central axial
passageway of the cannula 620 near the sharp tip 628. It will be understood
that a needle
assembly may be used to collect a sample other than of bone marrow within the
scope of the
present invention.
[00120] The obturator 626 is used to remove a lodged sample of bone marrow
that
has been collected in the central axial passageway of cannula 620. The
obturator 626
includes a grip 668 and a long, thin shaft 670 extending from the grip that is
sized to be
received in the central axial passageway of the cannula 620 in generally close
fitting relation
therein. The grip 668 is sized and shaped to be grasped by a user for
manipulating the
obturator 626, as will be described. As shown best in Figs. 34 and 35, a reset
member,
generally indicated at 672, extends from the grip 668 in the same direction as
the shaft 670.
In the illustrated sixth embodiment, the reset member 672 comprises projecting
portions 678
(e.g., three projecting portions) extending from the grip 668 in the same
direction as the shaft
6670. The grip 668 further comprises a protective collar 680 extending from
the grip 668 to
surround the projecting portions 678 and protect the projecting portions from
damage. The
collar 680 is further adapted to slidably receive the tubular housing 650 in
close-fitting
relation for proper alignment of the projecting portions 678, as will be
discussed in greater
detail below with respect to Fig. 31.
CA 02595683 2009-01-16
29
[00121] Figure 629 illustrates an initial position of the obturator 626 with
the shaft
670 entering the distal end of the tubular housing 650. The free end of the
shaft 670 has not
yet entered the central axial passageway of the cannula 620. As shown best in
Fig. 635, the
distal end of the tubular housing 650 includes the funnel-shaped guide 653
(broadly, "end
wall") for guiding the shaft 670 toward the opening 654 in the funnel-shaped
guide leading to
the central axial passageway of the cannula 620. The grip 668 is pushed to
advance the shaft
670 through the funnel-shaped guide 653 and into the central axial passageway,
which pushes
the sample toward the proximal end of the central axial passageway. Referring
to Fig. 30, the
shaft 670 is advanced until it protrudes out of the proximal end of the
central axial
passageway, thereby pushing the sample (not shown) out of the cannula 620
where it can be
collected in a Petri dish or other suitable container. As the shaft 670 is
advanced, it slides
through the funnel-shaped guide 653 at the distal end of the tubular housing
650. The
locking mechanism 652 remains engaged so that the safety shield 616 does not
move. In the
position shown in Fig. 30, free ends of the projecting portions 678 engage the
funnel-shaped
guide 653. Thus, the technician experiences a resistance to further inward
movement of the
shaft 670 into the central axial passageway of the cannula 620 because the
funnel-shaped
guide 653 is restricting movement of the projecting portions 678 of the
obturator 626. As
would be readily understood by one skilled in the art, the distal end of the
tubular housing
650 may be other than funnel-shaped according to the present invention. For
example, the
distal end may be generally orthogonal to the central axial passageway (or
concave or
convex) with an opening leading to the central axial passageway of the cannula
620.
[00122] The technician may observe the sample ejected from the central axial
passageway of the cannula 620. If it is determined that the sample is
satisfactory, the
obturator 626 can be pulled so that the shaft 670 slides back through and out
of the cannula
620. The needle assembly 610 can be discarded, or possibly but less likely,
cleaned and
sterilized for a subsequent use. If the sample is not satisfactory, however,
it will be necessary
to obtain a second sample from the same patient. This can be done using the
same needle
assembly 610, but the tubular housing 650 is locked in place by the locking
mechanism 652
over the sharp tip 628 of the cannula 620. The tubular housing 650 needs to be
moved away
from the tip 628 before the needle assembly 610 can be used to obtain a second
sample.
CA 02595683 2009-01-16
[00123] The obturator 626 of the present invention is particularly adapted to
permit
the tubular housing 650 to be released and moved back from the sharp tip 628
of the cannula
620, without requiring the technician to remove the contaminated obturator
from the cannula.
This allows the obturator 626 to be used to both eject the sample and reset
the safety shield
616 without utilizing an additional resetting device. This is advantageous
because the
technician can eliminate the extra steps of removing the obturator, locating
the resetting
device, and inserting the resetting device. Moreover, removing the obturator
626 is
undesirable because it is contaminated and its removal may contaminate
surrounding
surfaces. It should be understood, however, that even with the benefits of an
obturator having
resetting capabilities, a device other than an obturator 626 incorporating the
resetting, or
unlocking, features of the obturator described herein, but not functioning as
an obturator, is
also contemplated as within the scope of the present invention. From the
position shown in
Fig. 30, the grip 668 can be advanced toward the tubular housing 650 so that
the projecting
portions 678 are received into a corresponding number of holes 690 (see Fig.
35) in the
funnel-shaped guide 653 of the tubular housing. The holes 690 have a generally
rectangular
shape corresponding to the cross-sectional shape of the projecting portions
678, although
other hole shapes are also contemplated as within the scope of the claimed
invention. In the
example shown, the holes 690 have a different shape than the opening 654 to
encourage a
user of the device to correctly insert the cylindrical shaft 670 into the
opening and the
projecting portions 678 into the holes. The grip 668 and projection portions
678 are rotatable
together with respect to the tubular housing 650 about a longitudinal axis of
the shaft 670,
whereby the obturator 626 may be rotated to a particular angular orientation
relative to the
tubular housing so that the projecting portions precisely align with
respective holes 690.
Thus, only at this particular angular orientation will the projecting portions
678 be capable of
releasing the locking mechanism 652. Guiding structure (not shown) could be
provided to
guide the projecting portions 678 into the holes 690.
[00124] As depicted in the example of Fig. 35, three holes 690 of the tubular
housing 650 are arranged in a pattern having a first order rotational
symmetry. In other
words, the holes 690 of the tubular housing 650 (Fig. 35) and the projecting
portions 678 of
the obturator 626 (Figs. 33 and 34) will only fit together in one angular
orientation. In
another example (not shown), the holes 690 and projection portions 678 may be
located at
CA 02595683 2009-01-16
31
120 degree intervals relative one another, providing third order rotational
symmetry, whereby
the holes of the tubular housing 650 and the projecting portions of the
obturator 626 may fit
together in three distinct angular orientations. Other orders of rotational
symmetry (e.g.,
second, fourth, fifth, etc.) including a fewer or greater number of projection
portions 678 and
holes 690 are also contemplated as within the scope of the claimed invention.
Generally, a
higher order of rotational symmetry provides more angular orientations where
the holes 690
of the tubular housing 650 and the projecting portions 678 of the obturator
626 will fit
together for unlocking the safety shield 616. It should be understood that the
cross-sectional
areas and shapes of the projecting portions 678 and holes 690 need not be the
same, as long
as the holes are large enough to receive corresponding projecting portions.
Other means for
requiring a particular orientation of the obturator 626 with respect to the
tubular housing 650
for releasing the locking mechanism 652 are also contemplated as within the
scope of the
claimed invention (e.g., corresponding collar and tubular housing shapes,
mating channels,
etc.).
[00125] The safety shield 616 further comprises an unlocking mechanism,
generally
indicated 696, for selective, movable engagement with the locking mechanism
652 for
releasing the locking mechanism to permit the tubular housing 650 to move away
from the
sharp end 628 of the cannula 620. The unlocking mechanism 696 is movable
between a first
position in which it is free to lock the safety shield 616 in position
relative to the sharp end
628 of the cannula 620 and a second position in which the unlocking mechanism
releases the
locking mechanism 652 to permit movement of the safety shield relative to the
sharp end of
the cannula. In one example, the unlocking mechanism 696 comprises a generally
rigid body
such as a cylindrical sleeve 698, or other annular shape, slidably enclosed
within and
supported by the tubular housing 650 for movement relative to the tubular
housing and the
locking mechanism 652. In the example shown, the sleeve 698 moves freely
within the
tubular housing 650, although connections between the sleeve and the tubular
housing or the
sleeve and the base 656 are also contemplated as within the scope of the
invention.
Moreover, the sleeve 698 may be biased away from the base 656 to inhibit
inadvertent release
of the locking mechanism 652. With the projecting portions 678 aligned with
the holes 690,
the grip 668 can be advanced toward the tubular housing 650 so that the
projecting portions
678 pass through the holes 690 and into the tubular housing to engage the
sleeve 698 for
CA 02595683 2009-01-16
32
movement of the sleeve toward the base 656 of the canting member. During
advancement of
the grip 668, the collar 680 slidably, yet snugly, receives the tubular
housing 650 in relatively
close engagement to minimize canting of the collar with respect to the tubular
housing,
thereby facilitating proper alignment of the projecting portions 678 within
the holes 690.
Moreover, as a leading edge free portion of the sleeve 698 engages the base
656 of the
canting member, the sleeve wedges the base of the canting member up to a
position in which
the base is again substantially orthogonal to the axis of the cannula 620, as
shown in phantom
in Fig. 31. This positions the hole in the base 656 so that the cannula 620
can slide easily
through the canting member. In another example, the sleeve 698 may engage
another portion
of the canting member (e.g., the bent tab 664) to reset the canting member,
without departing
from the scope of the claimed invention.
[00126] Thus, as shown in Fig. 32, the tubular housing 650 can be grasped to
pull
back the safety shield 616 toward the distal housing member 624 so that the
sharp tip 628 of
the cannula 620 can be exposed. The obturator shaft 670 can be removed, as
shown in
phantom in Fig. 32, and the stylet 618 can be reinserted into the cannula 620
for a second
collection of a sample. It will be appreciated that the arrangement of the
projecting portions
678 and holes 690 such that only one angular orientation of the obturator 626
will unlock the
locking mechanism 652 inhibits the accidental release of the locking
mechanism. The
technician must intentionally align the projecting portions 678 and holes 690
to de-activate
the locking mechanism 652. In this manner, the funnel-shaped guide 653 acts as
a reset
inhibitor by only permitting de-activation the locking mechanism 652 with
proper alignment
of the projecting portions 678 and the holes 690.
[00127] As would be readily understood by one skilled in the art, the grip 668
may
additionally comprise a cavity 700 opposite the open collar 680 and projecting
portions 678
for accommodating the portion of the cannula 620 extending from the distal end
of the
tubular housing 650 when the projecting portions have fully extended into the
holes 690 of
the tubular housing.
[00128] Referring to Figs. 36-63, there are illustrated additional embodiments
of the
present invention incorporating a resettable feature. As shown in Figs. 36-43,
an obturator
761 having reset geometry 762 ("a reset member") interacts with a reset
element 763.
CA 02595683 2009-01-16
33
[00129] The obturator 761 may have a handle 770. The handle 770 may include a
cavity 765 to protect the needle 766 during resetting. The obturator 761 may
also include a
funnel 764 to guide the obturator 761 through the safety shield 769 to the
inner diameter of
the needle 766. The funnel 764 may include locating surfaces 767 on the
housing to facilitate
guiding. The funnel 764 is slidable along the obturator 761 such that the
funnel 764 allows
the obturator 761 to pass through the funnel 764. The funnel 764 may be a
separate piece.
The obturator 761 may also include a blocking element 768 positioned to
prevent resetting.
The blocking element 768 may also be movable relative to the obturator 761 so
that the
blocking element 768 may receive the safety shield 769 through the blocking
element to
allow the resetting geometry 762 to interact with the reset element 763. The
means for
moving the blocking element 768 includes, but is not limited to, levers,
hinges, buttons,
locks, snaps, detents, etc.
[00130] In this embodiment the obturator 761 is configured such that after the
obturator 761 is through the needle 766 and expels a sample, the blocking
element 768 in a
blocking position engages the safety shield 769 and precludes the resetting
geometry 762
from interacting with the reset element 763.
[00131] The blocking element 768 is then moved to a non-blocking position such
that the resetting geometry 762 interacts with the reset element 763. The
resetting geometry
762 interacts with the reset element 763 such that the binding member 760 is
released from a
locked position. This allows the safety shield 769 to be ready for reuse. It
is also envisioned
that the resetting geometry 762 may be placed in other locations on the
obturator 761
including, but not limited to, the opposite end of the obturator 761.
[00132] As illustrated in Figs. 44-47, a funnel 792 guides an obturator 791 to
the
inner diameter of a needle 796. The funnel 792 may be configured such that it
allows for a
locking or friction fit to the needle 796. The funnel 792 may also be
configured such that it
incorporates locating features 793 on the safety shield 799 for guiding the
obturator 791 to
the inner diameter of the needle 796. The locating features 793 on the safety
shield 799 may
also be configured such that a desirable fit is accomplished to maintain
position. Such fit
interfaces include, but are not limited to, snap fit, friction fit, detents,
etc. The option to use
the funnel 792 with or with out the safety shield 799 may be desirable so that
clinicians may
choose to use the funnel 792 with the safety shield 799 protecting the
contaminated sharp to
CA 02595683 2009-01-16
34
guide an obturator 791 to the inner diameter of the needle 796. This also
allows for
conventional use without safety devices.
[00133] Referring to Figs. 48-63, in certain applications it may be desirable
to
funnel an obturator through the needle device. It may also be desirable to
incorporate this
guiding member in a safety shield, which may require activation of the safety
shield prior to
using the funnel. Furthermore, it may be desirable to reset a binding member
that protects a
contaminated sharp (e. g. medical needle, stylet, etc.).
[00134] One embodiment illustrates a guiding member 802 that is integral to
the
safety shield 801. The guiding member 802 includes an interface of a
particular geometry that
allows for guiding a through-the-needle device, such as an obturator 803, etc.
The guiding
member 802 is configured such that the through-the-needle device 803 cannot
interfere with
the locking mechanism 804 in the safety shield 801. Other embodiments include
a geometry
that continues to allow for guiding of guiding member 802, but which also
provides reset
areas 806 for the safety shield 801.
[00135] Figures 50-51 show a guiding member 812 having flexible members 815
allowing the guiding member 812 to change sizes. This allows for guiding of a
through the
needle device 813 (e.g., an obturator). The flexible members 815 also allow
for a larger
opening that provides a reset area 816. The reset area 816 is an area that
will allow reset
geometry 817 ("reset member"), or other geometry that interacts with the reset
geometry 817,
to be brought into a position such that it interacts with the reset element
818 to allow the
locking mechanism 814 to be released from binding the safety shield 811 in
place on the
needle. This allows for the safety shield 811 to be ready for reuse.
[00136] As shown in Figs. 52-54, another embodiment includes a guiding member
822 having adjustable members 825 that can be positioned by a positioning
member 829. The
adjustable members 825 may be either rigid or flexible. The positioning member
829 may
include, but is not limited to, a sleeve, button, lever, collar, or other
member intended to
interact with the adjustable members 825. The adjustable members 825 are
configured such
that the positioning member 829 interact with the adjustable members 825
causing the
adjustable members 825 to be positioned so as to guide a through-the-needle
device 823 (e.g.,
an obturator). The adjustable members 825 may be configured such that a
tighter guiding
member 822 may be obtained, than otherwise may fit around the needle 820. The
positioning
CA 02595683 2009-01-16
member 829 may contain grip surfaces 824. The grip surfaces 824 may be
configured such
that upon subsequent activation of the safety shield 821, the positioning
member 829 will
position the flexible members 825 upon activation. The positioning member 829
may also be
configured such that the positioning member 829 may be repositioned wherein
the adjustable
members 825 provide a reset area 826.
[00137] As seen in Figs. 55-57, another embodiment is illustrated wherein a
guiding
member 832 is integrated with the obturator 831. The guiding member 832 may be
configured such that it remains attached to the obturator 831. The guiding
member 832 may
also be configured such that it is slidable along the obturator 831.
[00138] This embodiment depicts the guiding member 832 having a spring 833
(see
Figs. 56-57). The spring 833 may include, but is not limited to, a spring,
folded plastic,
telescoping features, line, wire, etc. It is configured such that the natural
resting position of
the guiding member 832 is at the end of the obturator 831. This allows for
guiding of the
obturator 831. The guiding member 832 is configured such that when the needle
830 is
brought toward the obturator 831, the guiding member 832 guides the needle to
the center.
This guiding takes place with little resistance. When the needle 830 contacts
the center of the
guiding member 832, there are locking surfaces 834 configured such that the
needle 830
tends to lock onto the guiding member 832, such as for example a luer taper.
After the needle
830 is locked onto the guiding member 832, continued motion tends to make the
guiding
member 832 slide along the obturator 831. The obturator 831 is then guided
into the needle
830 and expels the sample.
[00139] In another embodiment shown in Figs. 58 and 59, a shield 832' similar
to
the guiding member 832 is slidably secured to the obturator 831' so that the
obturator can
slide through the guiding member while compressing a spring 833'. The shield
832'
substantially covers the sharpened end of the needle 830' to protect the user
from an
accidental stick. The spring 833' keeps the shield 832' in place on the end of
the needle 830'
throughout the operation of removing the sample illustrated schematically in
Figs. 58 and 59.
The shield 832' may or may not have a guiding function for guiding the
obturator 831' into
the central passageway of the hollow needle 830'. The sharpened tip of the
needle 830' is
received in a tapered opening that also passes a shaft 831 A' of the obturator
831' through the
shield 832', but is blocked from passing through the shield by the size of the
opening. The
CA 02595683 2009-01-16
36
shaft 831A' of the obturator 831' will enter the central passageway of the
needle 830' as the
two parts are pushed further together (see, Fig. 59). However, the shield 832'
remains in
place, held by the sharpened end of the needle 830' and the bias of the spring
833'. As the
obturator 831' is removed from the needle 830', the bias of the spring 833'
keeps the shield
832' against the sharpened end of the needle so that the sharpened end is
substantially
covered at all times during the operation of removing the sample. Once the
shaft 831A' of the
obturator 831' is completely withdrawn from the needle 830', further
separation will move the
shield 832' off of the sharpened end of the needle so that the needle can be
used again.
Preferably, the shield 832' is retained on the obturator shaft 831A' at all
times.
[00140] As shown in Figs. 60-61, the obturator grip or handle 845 may be
configured such that reset geometry (or a "reset member") in the form of three
pins 847 is
integrated onto the obturator handle 845. The obturator handle 845 may also
contain locking
surfaces 844 configured such that the needle 840 tends to lock onto the
obturator handle 845.
The number of pins may be other than three within the scope of the present
invention.
[00141] Other embodiments include modifications to the end sensing member 852
(see Fig. 62). The end sensing member 852 includes needle communicating
surfaces 851 that
rides on the needle 850 and provides a force to resist binding. When the
geometry of the
needle 850 changes (e. g., end of the needle, needle grind, needle taper,
etc.), the end sensing
member 852 senses the change of the needle 850 and binding is no longer
resisted. Changing
the needle 850 geometry includes, but is not limited to, angled surfaces,
notched surfaces,
bumps, or any surface intended to amplify end sensing. Angled surfaces 854 are
shown in
Fig. 62. The angled surfaces 854 are configured such that a slight needle 850
geometry
change causes the angled surfaces 854 to translate dramatically. This is due
to the geometry
condition that exists from the angled surfaces 854.
[00142] Another embodiment is shown in Fig. 63 having a separate needle
communicating surface 861. This needle communicating surface 861 applies a
frictional force
to the needle 860. This force is used in combination with needle communicating
members
862 to oppose binding. The frictional force that opposes binding on the needle
860 is
available for geometry changes in the needle 860 that prevent the friction
forces from being
applied (e. g., needle taper, needle grind, end of the needle, etc.).
CA 02595683 2009-01-16
37
[00143] Referring now to Figs. 64 and 65, a safety shield 916 of a needle
assembly
is shown to comprise a tubular housing 950 containing a locking mechanism 952
substantially similar to the locking mechanisms (52, etc.) described above.
The safety shield
916 can be used with needle assemblies as shown and described previously
herein. In the
embodiment of Figs. 64 and 65, a reset member 972 comprises an annular
engaging portion
972A and a pair of slides 972B (broadly, "actuating members"). The engaging
portion 972A
is located inside the tubular housing 950 and the slides 972B are located on
the exterior of the
housing. The connection of the engaging portion 972A with the slides 972B
occurs through
respective slots 973 in the tubular housing. Moving the slides 972B in a
direction that is
generally parallel to the outer surface of the tubular housing 950 toward the
proximal end of
the tubular housing moves the engaging portion 972A into engagement with a
base 956 of the
locking mechanism 952. The engaging portion 972A can push the base 956 so that
the
locking mechanism 952 releases its lock on the needle (not shown), allowing
the safety shield
916 to be moved away from a sharpened end of the needle so that the needle can
be reused.
As described for earlier embodiments, in the release position the locking
mechanism base 956
is more nearly perpendicular to the longitudinal axis of the needle and arms
960 of the
locking mechanism are more nearly parallel to the longitudinal axis of the
needle. The reset
member 972 can be biased in a direction out of engagement with the locking
mechanism 952
so that it does not interfere with normal operation of the locking mechanism.
[00144] When introducing elements of the present invention or the preferred
embodiment(s) thereof, the articles "a", "an", "the" and "said" are intended
to mean that there
are one or more of the elements. The terms "comprising", "including" and
"having" are
intended to be inclusive and mean that there may be additional elements other
than the listed
elements. Moreover, the use of "up", "down", "top" and "bottom" and variations
of these
terms is made for convenience, but does not require any particular orientation
of the
components.
[00145] As various changes could be made in the above without departing from
the
scope of the invention, it is intended that all matter contained in the above
description and
shown in the accompanying drawings shall be interpreted as illustrative and
not in a limiting
sense.
