U.S. patent application number 13/163981 was filed with the patent office on 2011-10-13 for obturator with safety shield.
This patent application is currently assigned to TYCO HEALTHCARE GROUP LP. Invention is credited to David Rork Swisher, Joel D. Wiesner.
Application Number | 20110251518 13/163981 |
Document ID | / |
Family ID | 37662575 |
Filed Date | 2011-10-13 |
United States Patent
Application |
20110251518 |
Kind Code |
A1 |
Swisher; David Rork ; et
al. |
October 13, 2011 |
Obturator with Safety Shield
Abstract
An obturator for use with a needle assembly to remove a sample
of biological material collected in a hollow needle of the needle
assembly includes a grip for holding and manipulating the
obturator. A shaft extending from the grip is sized and shaped for
reception in a central axial passageway of the needle assembly for
pushing the sample out of the central axial passageway. A shield is
slidably supported on the shaft for engaging and shielding a sharp
end of the hollow needle when the obturator shaft is being inserted
into the needle to remove the sample.
Inventors: |
Swisher; David Rork; (St.
Charles, MO) ; Wiesner; Joel D.; (St. Peters,
MO) |
Assignee: |
TYCO HEALTHCARE GROUP LP
Mansfield
MA
|
Family ID: |
37662575 |
Appl. No.: |
13/163981 |
Filed: |
June 20, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11741529 |
Apr 27, 2007 |
7976498 |
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13163981 |
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PCT/US2005/038965 |
Oct 27, 2005 |
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11741529 |
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11179090 |
Jul 11, 2005 |
7828773 |
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PCT/US2005/038965 |
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11179438 |
Jul 11, 2005 |
7905857 |
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11179090 |
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Current U.S.
Class: |
600/567 |
Current CPC
Class: |
A61B 10/025 20130101;
A61M 5/3273 20130101; A61B 17/3472 20130101; A61B 2090/08021
20160201; A61B 17/3494 20130101; A61B 2010/0258 20130101 |
Class at
Publication: |
600/567 |
International
Class: |
A61B 10/02 20060101
A61B010/02 |
Claims
1. An obturator for use with a needle assembly to remove a sample
of biological material collected in a hollow needle of the needle
assembly, the obturator comprising: a grip for holding and
manipulating the obturator; a shaft extending from the grip, the
shaft being sized and shaped for reception in a central axial
passageway of the hollow needle for pushing the sample out of the
central axial passageway; a shield slidably supported on the shaft
for engaging and shielding a sharp end of the hollow needle when
the obturator shaft is being inserted into the needle to remove the
sample.
2. An obturator as set forth in claim 1 further comprising a spring
supported by the shaft and biasing the shield toward an end of the
shaft opposite the grip.
3. An obturator as set forth in claim 2 wherein the spring is a
coil spring and the shaft extends generally through the coil.
4. An obturator as set forth in claim 2 wherein the spring engages
the grip at one end of the spring and engages the shield at an
opposite end for biasing the shield on the shaft away from the
grip.
5. An obturator as set forth in any one of claim 1 in combination
with the needle assembly.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional application of co-pending
U.S. patent application Ser. No. 11/741,529, filed Apr. 27, 2007,
which is a continuation of PCT/US2005/038965, filed Oct. 27, 2005
(expired), which is a continuation of U.S. patent application Ser.
Nos. 11/179,090, and 11/179,438, both filed Jul. 11, 2005, the
entireties of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to needle assemblies and
more particularly to needle assemblies that have shields to cover
sharp ends of needles.
[0003] 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.
[0004] 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.
[0005] Some needle assemblies, including bone needle assemblies,
have associated safety mechanisms that shield the sharp tips of the
needle components when they are not 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.
[0006] 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
[0007] In one aspect of the present invention, an obturator for use
with a needle assembly to remove a sample of biological material
collected in a hollow needle of the needle assembly generally
comprises a grip for holding and manipulating the obturator. A
shaft extending from the grip is sized and shaped for reception in
a central axial passageway of the needle assembly for pushing the
sample out of the central axial passageway. A shield is slidably
supported on the shaft for engaging and shielding a sharp end of
the hollow needle when the obturator shaft is being inserted into
the needle to remove the sample.
[0008] Other objects and features of the present invention will be
in part apparent and in part pointed out hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective of a bone needle assembly including
an obturator;
[0010] 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;
[0011] 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;
[0012] FIG. 4 is the fragmentary elevation of FIG. 2 but showing
use of the obturator to reset a locking mechanism of the safety
shield;
[0013] 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;
[0014] FIG. 6 is an end elevation of the obturator;
[0015] FIG. 7 is a perspective of a needle assembly of a second
embodiment including an obturator;
[0016] 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;
[0017] 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;
[0018] 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;
[0019] 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;
[0020] FIG. 12 is a perspective of a needle assembly of a third
embodiment including an obturator;
[0021] FIG. 13 is a perspective of a modified obturator similar to
that of FIG. 12;
[0022] 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;
[0023] FIG. 15 is a perspective of an obturator of a needle
assembly of a fourth embodiment;
[0024] FIG. 16 is a fragmentary partial section of the obturator
partially inserted into the needle assembly with parts broken away
to show internal construction;
[0025] FIG. 17 is a perspective of a bone needle assembly of a
fourth embodiment including an obturator;
[0026] FIG. 18 is a fragmentary partial section of the needle
assembly with the obturator entering a safety shield of the needle
assembly;
[0027] 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;
[0028] FIG. 20 is the fragmentary elevation of FIG. 18 but showing
use of the obturator to reset a locking mechanism of the safety
shield;
[0029] 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;
[0030] FIG. 22 is a fragmentary perspective of the obturator with
parts broken away to show internal construction;
[0031] FIG. 23 is an end view of the obturator;
[0032] FIG. 24 is a fragmentary perspective of the obturator
entering the safety shield;
[0033] FIG. 25 is a fragmentary partial section of a needle
assembly of a fifth embodiment in a configuration similar to FIG.
19;
[0034] FIG. 26 is a fragmentary perspective of an obturator of the
needle assembly of FIG. 25;
[0035] FIG. 27 is a fragmentary perspective of an end of a shield
of the needle assembly of FIG. 25;
[0036] FIG. 28 is a perspective of a bone needle assembly of a
sixth embodiment including an obturator;
[0037] FIG. 29 is a fragmentary partial section of the needle
assembly with the obturator entering a safety shield of the needle
assembly;
[0038] 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;
[0039] FIG. 31 is the fragmentary elevation of FIG. 29 but showing
use of the obturator to reset a locking mechanism of the safety
shield;
[0040] 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;
[0041] FIG. 33 is a fragmentary perspective of the obturator with
parts broken away to show internal construction;
[0042] FIG. 34 is an end view of the obturator;
[0043] FIG. 35 is a fragmentary perspective of the needle assembly
showing the safety shield;
[0044] 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;
[0045] FIG. 37 is a perspective view of the obturator of FIG. 36
and another part of the needle assembly during resettable
engagement;
[0046] FIG. 38 is the perspective of FIG. 37 with parts broken away
to show internal construction;
[0047] FIG. 39 is an enlarged fragment of the perspective of FIG.
37;
[0048] FIG. 40 is the perspective of FIG. 37 with the obturator
inserted through a needle of the needle assembly;
[0049] FIG. 41 is the perspective of FIG. 40 with parts broken away
to show internal construction;
[0050] FIG. 42 is an enlarged fragment of the perspective of FIG.
41;
[0051] FIG. 43 is a perspective view of an obturator;
[0052] FIG. 44 is a perspective view of a funnel for guiding an
obturator;
[0053] FIG. 45 is a cutaway view of a funnel placed over a
needle;
[0054] FIG. 46 shows locating features on the safety shield for
guiding the obturator to the inner diameter of the needle;
[0055] FIG. 47 shows an obturator inserted into a funnel;
[0056] FIG. 48 is a perspective view of an alternative embodiment
of the medical needle shield apparatus according to the present
disclosure;
[0057] FIG. 49 is a cutaway view of the embodiment shown in FIG.
48;
[0058] FIG. 50 is an enlarged view of the safety shield of the
embodiment shown in FIG. 48;
[0059] FIG. 51 is a cutaway view of the safety shield having a
needle inserted;
[0060] FIG. 52 is a perspective view of the safety shield having an
obturator inserted;
[0061] FIG. 53 is an enlarged perspective view of the safety shield
having an adjustable guide;
[0062] FIG. 54 is an enlarged perspective view of the safety shield
having an adjustable guide with a reset area;
[0063] FIG. 55 is a guiding member integrated with an
obturator;
[0064] FIG. 56 is a guiding member integrated with an obturator
having a spring;
[0065] FIG. 57 is an enlarged view of the guiding member shown in
FIG. 56;
[0066] FIG. 58 is an elevation of a guiding member integrated with
an obturator of another embodiment just prior to mating with a
cannula;
[0067] FIG. 59 is the elevation of FIG. 58 with the obturator
inserted into the cannula;
[0068] FIG. 60 is an obturator handle having a resettable
feature;
[0069] FIG. 61 is an obturator handle having a resettable
feature;
[0070] FIG. 62 is an obturator handle having a resettable feature
inserted into a needle;
[0071] FIG. 63 is an alternative embodiment of the medical needle
shield apparatus according to the present disclosure;
[0072] FIG. 64 is a safety shield incorporating a reset member;
and
[0073] FIG. 65 is a longitudinal section of the safety shield.
[0074] Corresponding reference characters indicate corresponding
parts throughout the several views of the drawings.
DETAILED DESCRIPTION
[0075] 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.
[0076] 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 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.
[0077] 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.
[0078] 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 Ser. No. 11/146,173, filed
Jun. 6, 2005, the disclosure of which is incorporated herein by
reference.
[0079] 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.
[0080] 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 assembly may be
used to collect a sample other than of bone marrow within the scope
of the present invention.
[0081] 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.
[0082] FIG. 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 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.
[0083] 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 10 can be used to obtain a second sample.
[0084] 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.
[0085] 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.
[0086] 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.
[0087] FIGS. 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 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.
[0088] 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.
[0089] 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 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.
[0090] 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.
[0091] 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. 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.
[0092] 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.
[0093] 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 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.
[0094] 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.
[0095] 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.
[0096] 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 (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.
[0097] 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.
[0098] 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.
[0099] 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, 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.
[0100] 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
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 Ser. No. 11/146,173, filed
Jun. 6, 2005, the disclosure of which is incorporated herein by
reference.
[0101] 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.
[0102] 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 the reset plunger 470 is forcibly moved,
it normally does not interfere with the operation of the locking
mechanism 452.
[0103] 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.
[0104] 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. 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.
[0105] FIG. 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.
[0106] 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.
[0107] 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 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 may be 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.
[0108] 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 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.
[0109] 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.
[0110] 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. 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.
[0111] 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.
[0112] 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 members 622, 624 can be disconnected and
moved apart for removing the stylet 618 from the cannula 620.
[0113] 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 Ser. No.
11/146,173, filed Jun. 6, 2005, the disclosure of which is
incorporated herein by reference.
[0114] 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 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.
[0115] 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.
[0116] 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.
[0117] FIG. 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.
[0118] 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.
[0119] 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.
[0120] 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 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.).
[0121] 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 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.
[0122] 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.
[0123] 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.
[0124] 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.
[0125] 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.
[0126] 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.
[0127] 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.
[0128] 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 guide an obturator 791 to
the inner diameter of the needle 796. This also allows for
conventional use without safety devices.
[0129] 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.).
[0130] 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.
[0131] FIGS. 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.
[0132] 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 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.
[0133] 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.
[0134] 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.
[0135] 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 831A' of the
obturator 831' through the shield 832', but is blocked from passing
through the shield by the size of the opening. The 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.
[0136] 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.
[0137] 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.
[0138] 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.).
[0139] 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.
[0140] 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.
[0141] 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.
* * * * *