U.S. patent application number 11/928414 was filed with the patent office on 2008-03-20 for needle guards.
This patent application is currently assigned to SMITHS MEDICAL ASD, INC.. Invention is credited to David J. French, Richard C. Sircom.
Application Number | 20080071213 11/928414 |
Document ID | / |
Family ID | 34910712 |
Filed Date | 2008-03-20 |
United States Patent
Application |
20080071213 |
Kind Code |
A1 |
Sircom; Richard C. ; et
al. |
March 20, 2008 |
NEEDLE GUARDS
Abstract
A needle guard (1) based upon a canting plate (6) becomes
lockingly engaged with the needle (2) shaft both upon retraction of
the needle tip within the guard (1), and upon any attempt to cause
the needle tip to reemerge from the guard (1). The plate (6) is
positioned to rotate into locking engagement with the shaft of the
needle (2) both when an attempt is made to further withdraw the
needle from the needle guard (1) and when an attempt is made to
cause the needle tip to reemerge from the needle guard (1).
Inventors: |
Sircom; Richard C.;
(Dartmouth, CA) ; French; David J.; (Gatineau,
CA) |
Correspondence
Address: |
WOOD, HERRON & EVANS, LLP
2700 CAREW TOWER
441 VINE STREET
CINCINNATI
OH
45202
US
|
Assignee: |
SMITHS MEDICAL ASD, INC.
160 Weymouth Street
Rockland
MA
02370
|
Family ID: |
34910712 |
Appl. No.: |
11/928414 |
Filed: |
October 30, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10905884 |
Jan 25, 2005 |
|
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|
11928414 |
Oct 30, 2007 |
|
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60544352 |
Feb 17, 2004 |
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Current U.S.
Class: |
604/110 |
Current CPC
Class: |
A61M 2005/3247 20130101;
A61M 2005/325 20130101; A61M 5/3275 20130101; A61M 5/3273
20130101 |
Class at
Publication: |
604/110 |
International
Class: |
A61M 5/50 20060101
A61M005/50 |
Claims
1. A protective device for a needle having a needle tip and a
needle shaft, said device comprising: a containment case having a
cavity therein through which a needle is received; a canting plate
within said cavity, said plate having a hole through which the
needle is received, said hole having an inner face surface bounded
by first and second circumferential edges that provide a close
sliding fit around the needle; a sensing arm coupled to the canting
plate to align the circumferential edges for sliding engagement
with the needle while the needle tip protrudes from the containment
casing; resilient biasing means acting between the casing and the
sensing arm and canting plate to cause the canting plate to rotate
with respect to the needle upon withdrawal of the needle tip into
the containment cavity; a sensing limb on the sensing arm that
contacts the shaft of the needle before the needle is withdrawn
into the containment cavity, restraining the sensing arm and
canting plate from rotating so long as the sensing limb remains in
contact with the shaft of the needle, but permitting such rotation,
once the sensing limb ceases to be in contact with the shaft of the
needle; first and second pressure points present on the canting
plate and sensing arm; first and second abutment means present and
carried within the cavity of the containment case; wherein the
canting plate and sensing arm are aligned within the cavity for
respective contact between said first and second pressure points
and said first and second abutment means, the first pressure point
being positioned to engage with the first abutment means upon
withdrawal of the needle tip into the needle guard cavity, such
engagement effecting the canting of the canting plate, and the
second pressure point being positioned to engage with the second
abutment means once the canting late has assumed a canted
orientation whereby, upon any attempt to further retract the needle
from the needle guard, the canting of the canting plate causes the
first and second circumferential edges bounding the hole in the
canting plate to be directed into locking engagement with the
surface of the needle shaft, and, upon any attempt to cause
reemergence of the needle tip from the needle guard, contact
between the second pressure point and second abutment means tends
to rotate the canting plate so as to further engage the
circumferential edges with the surface of the needle shaft, to
thereby lockingly contain the needle tip within the containment
case of the needle guard against either further withdrawal of the
needle or reemergence of the needle tip.
2. The protective device of claim 1 wherein the sensing arm
comprises a limb that bears against the needle shaft while the
needle tip protrudes from the containment casing preventing the
canting plate from rotating with respect to the needle so long as
the limb on the sensing arm bears against the needle shaft, which
limb, upon retraction of the needle tip past this limb, becomes
free to rotate, allowing the canting plate to take up a canting
orientation that permits locking engagement of the needle guard
with the needle.
3. The protective device of claim 2 wherein the limb on the sensing
arm comprises a plate with a hole positioned and dimensioned to
receive the needle therethrough before the needle is withdrawn into
the needle guard.
4. The protective device of claim 2 wherein the limb on the sensing
arm comprises a plate with a slot positioned and dimensioned to
receive the needle therethrough before the needle is withdrawn into
the needle guard.
5. The protective device of claim 2 wherein the limb on the sensing
arm comprises a finger that prevents displacement of the limb and
sensing arm so long as the finger bears against the needle
shaft.
6. The protective device of claim 1, the canting plate being
shiftable with respect to the containment case in both longitudinal
directions of the needle.
7. The protective device of claim 1 further comprising a resilient
member positioned to bias the canting plate at one end for
displacement towards the needle tip.
8. A protective device for a needle having a needle tip and a
needle shaft, said device comprising: a containment case having a
cavity through which a needle is received; a canting plate within
said cavity, said plate having a hole through which the needle is
received, said hole having an inner face surface bounded by first
and second circumferential edges that provide a close sliding fit
around the needle, the canting plate being shiftable with respect
to the containment case in both longitudinal directions of the
needle; a sensing arm coupled to the canting plate to align the
circumferential edges for sliding engagement with the needle while
the needle tip protrudes from the containment casing; resilient
biasing means acting between the casing and the sensing arm and
canting plate to cause the canting plate to rotate with respect to
the needle upon withdrawal of the needle tip into the containment
cavity; a sensing limb on the sensing arm that contacts the shaft
of the needle before the needle is withdrawn into the containment
cavity, restraining the sensing arm and canting plate from rotating
so long as the sensing limb remains in contact with the shaft of
the needle, but permitting such rotation, once the sensing limb
ceases to be in contact with the shaft of the needle; first and
second pressure points present on the canting plate and sensing
arm; first and second abutment means present and carried within the
cavity of the containment case; a resilient member positioned to
bias the canting plate at one end for displacement towards the
needle tip; wherein the canting plate and sensing arm are aligned
within the cavity for respective contact between said first and
second pressure points and said first and second abutment means,
the first pressure point being positioned to engage with the first
abutment means upon withdrawal of the needle tip into the needle
guard cavity, such engagement effecting the canting of the canting
plate, and the second pressure point being positioned to engage
with the second abutment means once the canting late has assumed a
canted orientation whereby, upon any attempt to further retract the
needle from the needle guard, the canting of the canting plate
causes the first and second circumferential edges bounding the hole
in the canting plate to be directed into locking engagement with
the surface of the needle shaft, and, upon any attempt to cause
reemergence of the needle tip from the needle guard, contact
between the second pressure point and second abutment means tends
to rotate the canting plate so as to further engage the
circumferential edges with the surface of the needle shaft, to
thereby lockingly contain the needle tip within the containment
case of the needle guard against either further withdrawal of the
needle or reemergence of the needle tip.
9. The protective device of claim 8 wherein the sensing arm
comprises a limb that bears against the needle shaft while the
needle tip protrudes from the containment casing preventing the
canting plate from rotating with respect to the needle so long as
the limb on the sensing arm bears against the needle shaft, which
limb, upon retraction of the needle tip past this limb, becomes
free to rotate, allowing the canting plate to take up a canting
orientation that permits locking engagement of the needle guard
with the needle.
10. The protective device of claim 9 wherein the limb on the
sensing arm comprises a plate with a hole positioned and
dimensioned to receive the needle therethrough before the needle is
withdrawn into the needle guard.
11. The protective device of claim 9 wherein the limb on the
sensing arm comprises a plate with a slot positioned and
dimensioned to receive the needle therethrough before the needle is
withdrawn into the needle guard.
12. The protective device of claim 9 wherein the limb on the
sensing arm comprises a finger that prevents displacement of the
limb and sensing arm so long as the finger bears against the needle
shaft.
13. The protective device of claim 8 wherein the resilient member
comprises a pad.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. patent
application Ser. No. 10/905,884 filed Jan. 25, 2005 and U.S.
Provisional Application No. 60/544,352, filed Feb. 17, 2004, the
disclosures of which are incorporated by reference herein.
FIELD OF THE INVENTION
[0002] This invention relates to the field of medical devices. In
particular, it relates to providing protection for "sharps" such as
needles and wires that have been used on a subject and require
provision to prevent personnel from receiving a puncture wound from
the used device that may give rise to a risk of infection for such
personnel. As such, the invention may be characterized as a "needle
guard" although it is intended to apply equally to any sharp device
akin to a needle or wire that requires protection.
BACKGROUND OF THE INVENTION
[0003] U.S. Pat. No. 6,280,419 describes a needle guard device that
automatically engages with a needle when the tip of the needle is
withdrawn into an enclosing volume or cavity contained within the
protective device. The mechanism within the needle guard for
engaging with the needle operates on the principle of a canting
plate that has a hole through which the shaft of the needle passes.
Before deployment of the guard, the plate carrying the hole is
oriented perpendicularly to the axis of the needle shaft, and a
tight sliding fit exists between the needle shaft and the perimeter
of the hole. Once the tip of the needle has been withdrawn into the
guard, the plate is caused by a spring to "cant" or rotate from its
perpendicular orientation with respect to the needle shaft. By
reason of the tight sliding fit between the shaft and the hole in
the canting plate, the edge of the perimeter of the hole forcefully
engages with the surface of the needle, preventing further
retraction of the needle in the direction that would cause the
canting plate to cant at an even further angle.
[0004] In the design of the needle guard of U.S. Pat. No.
6,280,419, the canting plate acts to arrest the needle shaft
against further withdrawal of the needle shaft through the needle
guard's cavity. The canting action described above occurs when the
needle tip has been withdrawn into the cavity and a sensing arm
connected to the canting plate is able to shift its position due to
the retraction of the needle tip past an opening in a limb of the
sensing arm through which the needle passes prior to the initiation
of locking action.
[0005] In the specific design of the referenced patent, provision
is made for a wire to be present, passing through the core of the
needle and the body of the needle guard. As the needle guard and
needle are retracted, they slide along this wire. To permit such
movement to continue after the needle tip has entered within the
cavity of the needle guard, the opening in the limb on the sensing
arm is in the form of a slot. The bottom of the slot is large
enough to permit passage of the needle shaft before the needle
guard is deployed. The slot above the bottom is of a reduced width,
sufficient to allow passage of the wire, but narrow enough to
prevent the reemergence of the needle tip from the needle guard,
once the needle tip has withdrawn from the hole in the limb of the
sensing arm. The reemergence of the needle is prevented in this
design by the presence of the sides of the limb on the sensing arm
that define the borders of the slot. These sides remain in the path
that the needle tip would have to follow if it were to attempt to
re-emerge from the needle guard.
[0006] This system for preventing reemergence of the needle tip
from the needle guard depends critically upon the engagement of the
sidewall of the needle with the sides of the slot in the locking
limb on the sensing plate. As the needle wall is of a relatively
small thickness, this method for preventing reemergence of the
needle tip does not provide maximum reliability.
[0007] The present invention provides a system for preventing
reemergence of the needle tip which is an alternative to, and may
be more reliable than, the system described above.
[0008] The invention in its general form will first be described,
and then its implementation in terms of specific embodiments will
be detailed with reference to the drawings following hereafter.
These embodiments are intended to demonstrate the principle of the
invention, and the manner of its implementation. The invention in
its broadest and more specific forms will then be further
described, and defined, in each of the individual claims which
conclude this Specification.
SUMMARY OF THE INVENTION
[0009] The invention in one aspect is directed to a needle guard
having a containment case through which a needle projects. Within a
cavity within the case, there is a canting plate having an aperture
such as a hole, through which the needle projects, such hole having
an inner face surface bounded by first and second circumferential
edges that provide a close sliding fit around the needle. An
alignment means in the form of a sensing arm coupled to the canting
plate is provided to align the circumferential edges for sliding
engagement with the needle while the needle tip protrudes from the
containment casing. Resilient biasing means act between the casing
and the sensing arm to cause the canting plate to rotate with
respect to the needle upon withdrawal of the needle tip into the
containment cavity. This rotation occurs once the needle tip has
been withdrawn past a sensing limb on the sensing arm that may,
optionally, contain a slot, hole, or other opening. The canting of
the canting plate causes the first and second circumferential edges
bounding at the hole in the canting plate to be directed into
locking engagement with the surface of the needle shaft.
[0010] The canting plate is aligned within the cavity for
connection between first and second pressure points connected to
the canting plate and first and second abutment means present and
carried within the cavity of the containment case. The first
pressure point is positioned to engage with the first abutment
means upon withdrawal of the needle tip into the needle guard
cavity, such engagement effecting the canting of the canting plate
to resist further withdrawal of the needle once the tip is within
the needle guard. The second pressure point is positioned to engage
with the second abutment means once the canting plate has assumed a
canted orientation whereby, upon any attempt to cause reemergence
of the needle tip from the needle guard, contact between the second
pressure point and second abutment means tends to rotate the
canting plate so as to further engage the circumferential edges
with the surface of the needle shaft.
[0011] Thus attempted advancement of the needle in either direction
with respect to the containment case, once the canting plate is
canted with respect to the needle, causes pressure to be applied
through either of the pressure points by the abutment means to
effect further locking engagement of the circumferential edges with
the surface of the needle. The result is to lockingly contain the
needle tip within the containment case against either further
withdrawal of the needle or reemergence of the needle.
[0012] The sensing arm serves as an alignment means for the canting
plate to which it is connected. These parts rotate in unison.
Extending from the canting plate, the sensing arm contains a limb
which, through a hole, slot or finger, bears against the side of
the needle or needle shaft while the needle tip protrudes from the
containment casing. So long as the limb on the sensing arm bears
against the needle shaft, the canting plate cannot rotate with
respect to the needle. Upon retraction of the needle tip past this
limb of the sensing arm, the limb, the sensing arm and the
connected canting plate are free to rotate, allowing the canting
plate to take up a canting orientation that permits locking
engagement of the needle guard with the needle.
[0013] The limb on the sensing arm may be in the form of an
extension to the sensing arm that includes a plate with a hole or
slot positioned and dimensioned to receive the needle therethrough
before the needle is withdrawn into the needle guard. Or it may
simply comprise a finger that prevents displacement of the limb and
sensing arm so long as the finger bears against the needle
shaft.
[0014] As a supplemental protection against reemergence of the
needle from the needle guard case, a barrier portion of the limb
may be extended below the hole or slot formed therein, such barrier
portion resting in the path of the needle when the canting plate
has assumed a locking orientation.
[0015] By further variation of the invention, an alternate
supplemental reemergence barrier may be carried on a separate
biased supporting member with a sensing surface. This separate
supporting member is carried by the containment case, preferably on
the opposite side of the needle to the sensing arm of the locking
plate. When the needle tip is drawn past a separate barrier sensing
surface, the biased supporting member urges the reemergence barrier
into the path of the needle, thereby preventing reemergence of the
needle.
[0016] The needle guard according to the invention may be employed
with or without the presence of a wire passing through the core of
the needle. Thus the needle guard of the invention is suited for
incorporation with the designs of U.S. Pat. Nos. 5,458,658;
5,611,781 and 5,662,610 to Sircom, as well as with other designs
that rely upon the effect of a canting plate.
[0017] The foregoing summarizes the principal features of the
invention and some of its optional aspects. The invention may be
further understood by the description of the preferred embodiments,
in conjunction with the drawings, which now follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate embodiments of
the invention and, together with the general description of the
invention given above and the detailed description of the
embodiments given below, serve to explain the principles of the
present invention.
[0019] FIG. 1 is a cross-sectional side view of one embodiment of
the invention having a containment case containing a locking
mechanism of the invention in an armed condition;
[0020] FIGS. 2 and 3 are views similar to FIG. 1 showing the needle
withdrawn into the containment case and the locking mechanism
engaged with the needle, positioned to prevent further withdrawal
of the needle tip from the containment case or reemergence of the
needle tip, respectively;
[0021] FIG. 4 is a cross-sectional side view of a second embodiment
of the invention having a containment case containing a locking
mechanism and additional reemergence barrier mounted within the
case in an armed configuration; and
[0022] FIG. 5 is a view similar to FIG. 4 with the needle withdrawn
into the containment case and the locking mechanism engaged with
the needle.
DETAILED DESCRIPTION OF THE DRAWINGS
[0023] In FIG. 1, a containment case 1, which may cylindrically
surround a needle 2 with a tip 3, has seated therein a strip of
spring metal 4 which serves to provide the locking mechanism of the
invention. The base end 5 of the strip of metal 4 is seated in a
slot S in the inner wall of the containment case 1 with a close,
sliding fit to allow for slight displacement of base end 5. A
locking plate portion 6 of the strip 4 has an aperture 7 such as a
hole through which needle 2 projects. Strip 4 and plate 6 may be a
single piece of metal strip. Alternatively, locking plate portion 6
may be in the form of a hardened steel plate that is spot-welded to
thinner spring-sheld strip 4. Hole 7 is dimensioned to provide a
close sliding fit with needle 2 when the device is in the armed
condition shown in FIG. 1. The strip 4 extends with a sensing arm
segment or sensing arm 8 with a sensing end 9. The sensing arm 8
may be stiffened by a flange, as by being of "L" shape in
cross-section.
[0024] Extending from the sensing end 9 is a sensing means 10 which
hooks under the needle 2. The sensing means 10 may be the lower
portion of a plate which extends downwardly from the sensing end 9,
such plate having a hole or slot cut into it (seen in FIG. 2), or
may simply be a finger which extends under the needle 2.
[0025] A curved portion 11 of the strip 4 is spring-loaded, biasing
the locking plate portion 6 to seek to rotate in a clockwise
direction in the configuration as shown in FIG. 1. Curved portion
11 of strip 4 biases locking plate portion 6 for rotation, and so
portion 11 can be made of thinner spring or other like metal with
plate portion 6 being of thicker and harder material.
[0026] When the needle tip 3 is withdrawn to the right into the
containment case 1 past the sensing means 10 as shown in FIG. 2,
the sensing means 10 is released to rotate clockwise and upwardly
under the urging of the curved, spring-loaded portion 11. The
sensing arm 8 also rises upwardly, rotating in the clockwise
direction as well. Adjacent inner wall 29 of case 1 may be shaped
to conform to the path of travel of end 9 as sensing arm 8 swings
upwardly. That upward swinging motion, in turn, urges the locking
plate 6 to rotate in a clockwise direction. Because of the close
sliding fit between the needle 2 and hole 7, rotation of the
locking plate 6 is almost immediately arrested. Also, base end 5
may displace within slot 6 leaving a small gap S.sub.G as seen in
FIG. 2 as strip 4 is carried with needle 2.
[0027] A first buttressing surface 12 on the inner surface of the
case 1 receives the lower end 13 of the locking plate portion 6 of
the strip 4. Further attempts to withdraw the needle 2 from the
case 1 (to the right in FIG. 3) urge the locking plate 6 to rotate
further in the clockwise direction. Due to the adjacent edges of
the hole 7 engaging with the surface of the needle 2, substantial
actual rotation does not take place, but the locking plate 6 locks
firmly into place on the surface of the needle 2, thus preventing
further withdrawal of needle 2 from case 1.
[0028] When an attempt is made to advance the needle 2 for
reemergence from the case 1, which would be to the left as shown in
FIG. 3, the now upwardly rotated sensing arm 8 is carried forward
within the case 1 until the upper portion 14 and end 9 of the
sensing arm 8 abut against a second abutment 15 on the interior of
the case 1. Simultaneously, the base end 5 of the strip 4 may shift
forward into gap S.sub.G. Any further attempt at advancement of the
needle 2 to the left for reemergence from the case 1 applies a
force to the upper end 16 of the locking plate 6. As previously,
this urges the locking plate 6 to rotate, to thereby effect a
further locking engagement with the needle 2. Second abutment 15 is
advantageously defined within notch or recess 25 and may present a
receding face to end 9. Also, slot S may alternatively open
upwardly into case 1 as depicted, for sake of convenience, in only
FIG. 3, with the sidewalls 26 (only one shown) of slot S providing
confinement to orient strip 4 to ensure that end 9 is aligned with
abutment surface 15.
[0029] When the upper portion 14 of the sensing arm 8 first rises
to its rotated orientation as shown in FIG. 2, it becomes aligned
with second abutment 15. Notch or recess 25 may be in the form of a
circumferential groove following the curvature of the confinement
case 1 thereat to facilitate the desired alignment. Additionally,
the first abutment 12 may carry a resilient member 17, such as a
resilient pad or coiled spring (the latter not shown), that serves
to assist in shifting the base end 5 forwardly in its slot and to
maintain a rotational bias of locking plate 6 towards engagement
with needle 2.
[0030] The motion depicted in FIG. 3 whereby the upper portion 14
and end 9 of the sensing arm 8 has shifted into abutting contact
against the second abutment 15 is minimal. The resilient member 17
at the location of the first abutment 12 helps ensure that the
lower end of the locking plate 13 is carried forwardly during this
slight advancement of the needle, retaining the locking plate 6 in
its locking orientation. This further ensures that the locking
plate 6 is urged to rotate to effect the further locking engagement
with the needle 2. Where member 17 is a resilient pad, the pad may
be comprised of resilient polymeric material.
[0031] While the needle guard as described in FIGS. 1 to 3 is
locked in place against movement of the needle 2, to prevent
further withdrawal or reemergence of the needle tip 3 from the case
1, a supplemental reemergence barrier 20 may be provided as seen in
FIGS. 4 and 5. This barrier is provided by a second spring-biased
strip 21 seated at its base end in a slot 22 within the inner
surface of the case 1. At the other end of this second strip 21, a
barrier plate 23 is provided with a sensing end 27.
[0032] In FIG. 4, the sensing end 27 bears against the side of the
needle 2. In FIG. 5 the needle tip 3 has been withdrawn past the
sensing end 27, whereupon the spring bias within the strip 21
causes the reemergence barrier plate 23 to rise into the path of
the needle 2. Any attempt to advance the needle thereafter for
reemergence will be arrested by the reemergence barrier plate
23.
[0033] In this manner, extra security may be provided against the
reemergence of the needle tip 3 from the case 1.
[0034] While the present invention has been illustrated by the
description of embodiments thereof, and while the embodiments have
been described in considerable detail, it is not intended to
restrict or in any way limit the scope of the appended claims to
such detail. Additional advantages and modifications will readily
appear to those skilled in the art. The invention in its broader
aspects is therefore not limited to the specific details,
representative apparatus and methods and illustrative examples
shown and described. Accordingly, departures may be made from such
details without departing from the scope or spirit of the general
inventive concept.
* * * * *