U.S. patent application number 10/706795 was filed with the patent office on 2004-05-20 for single-use syringe.
Invention is credited to Capes, David Francis, Pons, Martin Clapes, Villas, Marcos Calucho.
Application Number | 20040097884 10/706795 |
Document ID | / |
Family ID | 27383106 |
Filed Date | 2004-05-20 |
United States Patent
Application |
20040097884 |
Kind Code |
A1 |
Capes, David Francis ; et
al. |
May 20, 2004 |
Single-use syringe
Abstract
A syringe includes a barrel having a fluid chamber, a proximal
end, a distal end and an elongated tip extending from the distal
end and having a passageway therethrough in fluid communication
with the chamber. A collar surrounds the tip and includes at least
one deflectable locking tab projecting radially inwardly from the
collar. The locking tab is adapted to engage the hub of a needle
assembly to prevent removal of a needle assembly away from the tip.
The locking tab is configured to allow the assembly of the needle
assembly to the barrel through axial motion of the hub toward the
barrel. A plunger is provided for drawing fluid into and out of the
barrel. The plunger includes an elongated plunger rod having a
proximal portion and a distal portion connected by a breakable
connection. The breakable connection is strong enough to hold the
proximal portion and distal portion together during normal use of
the syringe and breakable upon application of additional force to
the proximal portion.
Inventors: |
Capes, David Francis;
(Singapore, SG) ; Villas, Marcos Calucho;
(Fraga-Huesca, ES) ; Pons, Martin Clapes;
(Alcobendas - Madrid, ES) |
Correspondence
Address: |
BECTON, DICKINSON AND COMPANY
1 BECTON DRIVE
FRANKLIN LAKES
NJ
07417-1880
US
|
Family ID: |
27383106 |
Appl. No.: |
10/706795 |
Filed: |
November 12, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10706795 |
Nov 12, 2003 |
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09941030 |
Aug 28, 2001 |
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10706795 |
Nov 12, 2003 |
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09274117 |
Mar 23, 1999 |
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6361525 |
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09274117 |
Mar 23, 1999 |
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09249431 |
Feb 12, 1999 |
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09249431 |
Feb 12, 1999 |
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09124447 |
Jul 29, 1998 |
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Current U.S.
Class: |
604/240 |
Current CPC
Class: |
A61M 5/3134 20130101;
A61M 5/5066 20130101; A61M 39/10 20130101; A61M 25/0014 20130101;
A61M 2005/3279 20130101; A61M 2005/31516 20130101; A61M 5/50
20130101; A61M 5/5013 20130101; A61M 5/348 20130101 |
Class at
Publication: |
604/240 |
International
Class: |
A61M 005/00 |
Claims
What is claimed is
1. A syringe comprising: a barrel having a fluid chamber, a
proximal end, a distal end and an elongated tip extending from said
distal end having a passageway therethrough in fluid communication
with said chamber, a collar surrounding said tip, and at least one
deflectable locking tab projecting radially inwardly from said
collar a needle assembly including a cannula having a proximal end,
a distal end and a lumen therethrough, a hub having an open
proximal end with a cavity therein, and a distal end joined to said
proximal end of said cannula so that said lumen is in fluid
communication with said cavity, an outside surface of said hub,
said needle assembly being connected to said barrel so that said
elongated tip of said barrel is in said cavity of said hub and said
outside surface on said hub is adjacent to said locking tab so that
said locking tab prevents removal of said needle assembly from said
barrel through contact between said locking tab and said outside
surface of said hub, said locking tab being configured to allow
assembly of the needle assembly to said barrel through axial motion
of the hub toward the barrel; and a plunger including an elongated
plunger rod having a longitudinal axis, a proximal portion and a
distal portion connected by a breakable connection, said distal
portion including a stopper slidably positioned in fluid-tight
engagement with an inside surface of said chamber for drawing fluid
into and out of said chamber by movement of said plunger relative
to said barrel, said breakable connection being strong enough to
hold said proximal portion and said distal portion together during
normal use of said syringe and breakable upon application of an
additional force to said proximal portion.
2. The syringe of claim 1 wherein one of said proximal portion and
said distal portion includes an axial projection having a plurality
of transverse protuberances projecting therefrom, said
protuberances being connected to the other of said proximal portion
and said distal portion, said breakable connection being on said
protuberances.
3. The syringe of claim 1 wherein the at least one deflectable
locking tab comprises a plurality of locking tabs.
4. The syringe of claim 3 wherein the tabs are cantilevered members
extending radially inward and proximally from the collar.
5. The syringe of claim 1 further comprising means on the hub
between the distal end and the proximal end of the hub for allowing
the hub to break upon application of bending force to the hub.
6. A syringe comprising: a barrel having a fluid chamber, a
proximal end, a distal end and an elongated tip extending from said
distal end having a passageway therethrough in fluid communication
with said chamber, a collar surrounding said tip, and at least one
deflectable locking tab projecting radially inwardly from said
collar a needle assembly including a cannula having a proximal end,
a distal end and a lumen therethrough, a hub having an open
proximal end with a cavity therein, and a distal end joined to said
proximal end of said cannula so that said lumen is in fluid
communication with said cavity, an outside surface of said hub, a
fracturable section between said proximal end and said distal end
of said hub for allowing said hub to break upon application of a
bending force to said hub, said needle assembly being connected to
said barrel so that said elongated tip of said barrel is in said
cavity of said hub and said outside surface on said hub is adjacent
to said locking tab so that said locking tab prevents removal of
said needle assembly from said barrel through contact between said
locking tab with said outside surface of said hub, said locking tab
being configured to allow assembly of the need assembly to said
barrel through axial motion of the hub toward the barrel; and a
plunger including an elongated plunger rod having a longitudinal
axis, a proximal portion and a distal portion connected by a
breakable connection, said distal portion including a stopper
slidably positioned in fluid-tight engagement with an inside
surface of said chamber for drawing fluid into and out of said
chamber by movement of said plunger relative to said barrel, said
breakable connection being strong enough to hold said proximal
portion and said distal portion together during normal use of said
syringe and breakable upon application of an additional force to
said proximal portion so that said proximal portion can be removed
from said syringe barrel and said distal portion remains in said
barrel.
7. The syringe of claim 6 wherein the at least one deflectable
locking tab comprises a plurality of locking tabs and wherein the
tabs are cantilevered members extending radially inward and
proximally from the collar.
8. The syringe of claim 7 wherein one of said proximal portion and
said distal portion includes an axial projection having a plurality
of transverse protuberances projecting therefrom, said
protuberances being connected to the other of said proximal portion
and said distal portion, said breakable connection being on said
protuberances.
9. A syringe comprising: a barrel having a fluid chamber, a
proximal end, a distal end and an elongated tip extending from said
distal end having a passageway therethrough in fluid communication
with said chamber, and a collar surrounding said tip; a needle
assembly including a cannula having a proximal end, a distal end
and a lumen therethrough, a hub having an open proximal end with a
cavity therein, and a distal end joined to said proximal end of
said cannula so that said lumen is in fluid communication with said
cavity, an outside surface of said hub, said needle assembly being
connected to said barrel so that said elongated tip of said barrel
is in said cavity of said hub and means for preventing removal of
said needle assembly from said barrel; and a plunger including an
elongated plunger rod having a longitudinal axis, a proximal
portion and a distal portion connected by a breakable connection,
said distal portion including a stopper slidably positioned in
fluid-tight engagement with an inside surface of said chamber for
drawing fluid into and out of said chamber by movement of said
plunger relative to said barrel by exertion of an operation force
to the proximal portion of the plunger, said connection being
adapted to hold said proximal portion and said distal portion
together during operation of the syringe until the stopper is
disposed near the distal end of the barrel, and means for allowing
said connection to break by application of breaking force to said
proximal portion of the plunger while the stopper is disposed near
the distal end of the barrel, wherein the breaking force is greater
than the operation force.
10. The syringe of claim 9 wherein the means for allowing the
connection to break includes a plurality of transverse
protuberances projecting from one of said proximal portion and said
distal portion, said protuberances being connected to the other of
said proximal portion and said distal portion.
11. The syringe of claim 9 wherein the means for preventing removal
of said needle assembly from said barrel includes a plurality of
cantilevered members extending radially inward and proximally from
the collar.
12. The syringe of claim 9 further comprising means on the hub
between the distal end and the proximal end of the hub for allowing
the hub to break upon application of bending force to the hub.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a continuation-in-part of U.S.
patent application Ser. No. 09/249,431 filed on Feb. 12, 1999 which
is a continuation-in-part of U.S. patent application Ser. No.
09/124,447 filed on Jul. 29, 1998.
FIELD OF THE INVENTION
[0002] The present invention relates to a syringe having a
breakable plunger rod to prevent further use of the syringe after
fluid delivery or injection. The present invention also relates to
fluid transfer devices having improved needle attaching features
and in particular, structure to help prevent the removal of a
hypodermic needle assembly from a fluid transfer device such as a
hypodermic syringe.
BACKGROUND
[0003] Throughout the world the re-use of hypodermic syringe
products which are intended for single-use only is instrumental in
drug abuse and in the transfer of contagious diseases. Intravenous
drug users who routinely share and re-use syringes are a high-risk
group with respect to the AIDS virus. Also, the effects of multiple
use are a major concern in some countries where the repeated use of
syringe products during mass inoculation. programs may be
responsible for the spread of many diseases. Syringes are often
recycled in developing countries without proper sterilization.
[0004] Many attempts have been made to remedy this problem. Some
designs involve the inclusion of structure which will allow the
destruction or defeating of the syringe function through a
conscious act by the user, such as breaking a syringe or one of its
components. In addition, there are single-use hypodermic syringes
which become incapable of further use automatically upon delivery
of the medication without any additional act on the part of the
user. Such syringes are taught in U.S. Pat. No. 4,961,728.
[0005] With single-use syringes using needle assemblies having a
hub attached to a needle cannula there is a need to prevent the
removal of the needle assembly after the use of the single-use
syringe so that the needle assembly cannot be used again with other
syringes. In addition to preventing the removal of the needle
assembly, there is also a need for structure which will allow the
easy attachment of the needle assembly to the syringe so that the
needle assembly may be attached at the time of use and an
appropriately sized needle may be used.
SUMMARY OF THE INVENTION
[0006] A fluid transfer device comprises a barrel having a fluid
chamber, a proximal end, a distal end and an elongated tip
extending from the distal end having a passageway therethrough in
fluid communication with the chamber. A collar surrounds the tip.
For the purposes of the present invention collar is intended to
include not only continuous structures but also discontinuous
structures such as a wall with gaps in its structure. At least one
deflectable locking tab projects radially inwardly from the collar
and is adapted to engage the hub of a needle assembly to prevent
the removal of the needle assembly away from the tip. The locking
tab is configured to allow assembly of the needle assembly to the
barrel through axial motion of the hub toward the barrel.
[0007] Another embodiment of the present fluid transfer device
includes a needle assembly having a cannula with a proximal end, a
distal end, and a lumen therethrough. A hub includes an open
proximal end with a cavity therein and a distal end is joined to
the proximal end of the cannula so that the lumen is in fluid
communication with the cavity. The hub includes an outside surface.
A barrel having a fluid chamber includes an open proximal end, a
distal end and an elongated frusto-conically shaped tip extending
from the distal end having a passageway therethrough in fluid
communication with the chamber. A collar surrounding the tip
includes a plurality of deflectable locking tabs projecting
radially and proximally inwardly from the collar defining an inner
aperture surrounding the tip. The tip extends distally beyond the
aperture defined by the locking tabs. The needle assembly is
connected to the barrel so that the elongated tip of the barrel is
in the cavity of the hub and the outside surface of the hub is
adjacent to the inner aperture defined by the locking tabs so that
the locking tabs prevent removal of the needle assembly from the
barrel through contact between the locking tabs and the outside
surface of the hub.
[0008] Another embodiment of the present fluid transfer device
includes means on the hub between the distal end of the hub and the
proximal end of the hub for allowing the hub to break upon
application of a bending force to the hub. Such means includes a
fracturable section between the proximal end and the distal end of
the hub such as an annular discontinuity on the outside surface of
the hub or an annular discontinuity in the cavity of the hub. The
fracturable section is provided to prevent removal of the needle
assembly from the fluid transfer device by allowing the hub to
break if an excessive bending force is applied to the hub.
[0009] Another embodiment of the present invention includes a
plunger having an elongated plunger rod, a proximal portion and a
distal portion. The distal portion includes a stopper slidably
positioned in fluid-tight engagement with an inside surface of the
barrel for drawing fluid into and out of the barrel by movement of
the plunger relative to the barrel. The plunger further includes
means for allowing the connection between the proximal portion of
the plunger rod and the distal portion of the plunger rod to break
upon application of additional force to the proximal portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective view of a fluid transfer device of
the present invention with a needle assembly attached;
[0011] FIG. 2 is an exploded prospective view of the fluid transfer
device and needle assembly of FIG. 1;
[0012] FIG. 3 is an enlarged cross-sectional view of the fluid
transfer device of FIG. 2 taken along line 3-3;
[0013] FIG. 4 is a side-elevational view of the left side of the
fluid transfer device of FIG. 2;
[0014] FIG. 5 is an enlarged partial cross-sectional view of the
needle assembly and fluid transfer device of FIG. 1 taken along
line 5-5;
[0015] FIG. 6 is a perspective view of the needle assembly of FIG.
2;
[0016] FIG. 7 is an alternative needle assembly, similar to the
needle assembly of FIG. 6;
[0017] FIG. 8 is an enlarged partial cross-sectional view of an
alternative fluid transfer device of the present invention;
[0018] FIG. 9 is an enlarged cross-sectional view of another
alternative embodiment of the present invention;
[0019] FIG. 10 is an enlarged side-elevational view of an
alternative embodiment of the present invention including a
flexible tube;
[0020] FIG. 11 is an enlarged cross-sectional view of the fluid
transfer device of FIG. 10 taken along line 11-11;
[0021] FIG. 12 is an enlarged cross-sectional view illustrating the
barrel of the fluid transfer device of FIG. 2 during the
manufacturing process;
[0022] FIG. 13 is a side elevational view of an alternative
embodiment of the fluid transfer device of the present
invention;
[0023] FIG. 14 is an enlarged cross-sectional view of the fluid
transfer device of FIG. 13 taken along line 14-14;
[0024] FIG. 15 is a side-elevational view of the fluid transfer
device of FIG. 13 illustrating the hub breaking upon application of
a bending force;
[0025] FIG. 16 is an enlarged cross-sectional view of another
alternative fluid transfer device;
[0026] FIG. 17 is a perspective view of the plunger of an
alternative embodiment of the present invention;
[0027] FIG. 18 is a side elevation view of a syringe assembly using
the plunger of FIG. 17;
[0028] FIG. 19 is a side elevational view of the syringe of FIG. 18
illustrated with a force being applied to break the connection to
the proximal and distal ends of the plunger rod; and
[0029] FIG. 20 is a side elevational view of the syringe of FIG. 19
illustrating the separated proximal and distal ends of the plunger
rod.
DETAILED DESCRIPTION
[0030] While this invention is satisfied by embodiments in many
different forms, there is shown in the drawings and will herein be
described in detail preferred embodiments of the invention with the
understanding that the present disclosure is to be considered as
exemplary of the principles of the invention and is not intended to
limit the invention to the embodiments illustrated. The scope of
the invention will be measured by the appended claims and their
equivalents.
[0031] Adverting to FIGS. 1-7 a fluid transfer device such as
syringe 20 includes a barrel 21 having a barrel inside surface 22,
a fluid chamber 23, a proximal end 25, a distal end 27 and an
elongated tip 28 extending from the distal end having a passageway
29 therethrough in fluid communication with the chamber. In this
embodiment the elongated tip is preferably frusto-conically
shaped.
[0032] Barrel 21 further includes a collar 31 having an inside
surface 32 and at least one deflectable locking tab projecting
radially inwardly from the collar. The collar preferably but not
necessarily surrounds the tip. In this preferred embodiment, there
are a plurality of locking tabs 34 projecting radially and
proximally inwardly from the inside surface. In this preferred
embodiment a distal end 30 of elongated tip 28 extends distally
beyond distal end 33 of the collar. It is preferable that the
collar and the locking tabs are integrally formed of a single
material preferably a metal such as stainless steel or a plastic
material such as polypropylene. Also, the collar can be made of
thermoplastic material and the locking tabs of metal, such as
stainless steel attached to the collar.
[0033] The fluid transfer device of the present invention is
intended to be used with a needle assembly 40 including a cannula
41 having a proximal end 43 a distal end 44 and a lumen 45
therethrough. The needle assembly also includes a hub 47 having an
open proximal end 49 with a cavity 50 therein, and a distal end 51
joined to proximal end 43 of cannula 41 so that lumen 45 is in
fluid communication with cavity 50. Hub 47 also includes outside
surface 52. The hub in this embodiment preferably, but not
necessarily, includes at least one projection extending radially
outwardly from outside surface 52 of the hub. This embodiment
includes two projections 53. It is within the purview of the
present invention to include needle assemblies having one-piece
construction wherein the cannula and the hub are formed of one
piece.
[0034] Some prior art syringe barrels include a collar around the
distal tip having a thread on the inside surface of the collar.
This configuration is often referred to as a locking luer collar. A
needle assembly having a hub with outwardly extending projections
is placed on the distal end of the syringe by aligning the distal
tip of the syringe with a cavity in the hub and moving the needle
assembly toward the syringe so that the outward projections of the
hub engage the thread. The needle assembly is then rotated or
screwed into the locking luer collar so that the needle assembly is
held tightly on the distal tip of the syringe barrel through
interaction of the locking luer collar thread and the projections
on the hub. This is an excellent structure for most applications
since it allows for applying the appropriate sized needle assembly
at the time of use and for changing needle assemblies during a
procedure which may require two or more different sizes. However,
for many applications it is not desirable to have structure which
provides for the easy removal of the needle assembly. For example,
in mass inoculation programs using single-use syringes, a needle
assembly which is not removable compliments the syringe assembly
which is not reusable. Although most healthcare institutions have
procedures for disposal of used fluid transfer devices, an
unscrupulous healthcare worker can, if the structure allows, remove
the relatively small hypodermic needle assembly before disposing of
the larger syringe assembly catheter or I.V. set.
[0035] The present invention provides structure to prevent removal
of the needle assembly during normal use of the fluid transfer
device. In particular, the locking tab projecting radially inwardly
from the inside surface of the collar is adapted to engage the
outside surface of the hub of the needle-assembly to prevent
removal of the needle assembly away from the tip of the barrel. The
locking tab is configured to allow assembly of needle assembly to
the syringe barrel through axial motion of the hub toward the
barrel. In use, the needle assembly is connected to the barrel by
moving the needle assembly toward the barrel so that elongated tip
28 of the barrel is in cavity 50 of the hub and outside surface 52
of the hub is adjacent to locking tabs 34 so that the locking tab
prevents removal of the needle assembly from the barrel through
contact of the locking tabs with the outside surface of the hub.
Accordingly, the force for removal of the needle assembly from the
syringe is much higher than the force for installation of the
needle assembly to the barrel. This is an important feature of the
present invention.
[0036] Although only one locking tab is required for the present
invention, the preferred embodiment illustrated herein includes a
plurality of locking tabs 34 which are deflected by the proximal
end and/or the outside surface of the hub when the needle assembly
is installed onto the barrel. Tabs 34 are separated by gaps 35 to
allow them to flex more freely and provide for lower forces when
attaching the needle assembly to the barrel. The locking tabs
include distal ends 37 which in this preferred embodiment describe
a opening 39 which is preferably circularly shaped and smaller than
the outside surface of the hub and/or the width described by
projections 53 so that the locking tabs deflect when the needle
assembly is installed onto the barrel. Because the locking tabs are
facing radially and proximally inwardly after needle attachment
they are very resistant to flexing outwardly to allow the removal
of the needle assembly, as best illustrated in FIG. 5. Some portion
of the outside surface of the hub preferably describes a dimension
which is larger than the opening 39 described by the distal ends 37
of the locking tabs so that an attempt to remove the needle
assembly there will not be enough space for the tabs to move
towards a position which is perpendicular to the longitudinal axis
of the barrel.
[0037] In this preferred embodiment, the needle assembly includes
projections 53 projecting outwardly from the outside surface of the
hub to help prevent removal of the needle assembly from the barrel
through contact between the locking tabs and the projections. The
present invention can accomplish its purpose without the radial
projection or projections on the hub however the projection or
projections provide a stronger attachment of the needle assembly to
the barrel and allow for more liberal tolerances for the locking
tab dimensions.
[0038] An alternate needle assembly 140 is illustrated in FIG. 7.
This needle assembly is similar to the needle assembly 40 and
includes cannula 141 and hub 147. Hub 147 includes one projection
153 extending 360.degree. around the hub. This structure is
especially desirable if only one or two locking tabs are used so
that it is not necessary to align the projection on the needle hub
with the locking tabs since the projection on the hub will always
be positioned so that it can contact a locking tab.
[0039] The syringe of the present embodiment further comprises a
plunger 59 including a plunger rod 61 having an elongated body
portion 62 having a proximal end 63, a distal end 64 and a stopper
65 at the distal end. The stopper is slidably positioned in
fluid-tight engagement with the barrel inside surface. The plunger
rod extends outwardly from proximal end 25 of the barrel. The
plunger rod is accessible outside of proximal end 25 of the barrel
and is provided to move the stopper along the barrel to force fluid
into and out of chamber 23 through passageway 29. Disc-shaped
plunger rod flange 67 is provided as a convenient structure for
applying forces to move the plunger rod with respect to barrel 21.
A flange 26 is also provided at the proximal end of the barrel to
facilitate handling and for maintaining the relative position of
the barrel with respect to the plunger rod during fluid transfer
using known procedures.
[0040] It is within the purview of the present invention to include
plunger rods and stoppers which are separately formed or integrally
formed of the same material or different materials such as in
two-color molding, or separately formed of the same or different
materials and joined together by mechanical means, adhesives,
ultrasonic welding, heat sealing or other suitable means. It is
understood that the plunger of the present embodiment merely
illustrates these many possibilities.
[0041] FIG. 8 illustrates an alternative embodiment of the present
invention. This embodiment is structurally and functionally similar
to the embodiment of FIGS. 1-7. In this embodiment, barrel 121
having a chamber 123, a distal end 127 and an elongated.
frusto-conically shaped tip 128 extending from the distal end and
having a passageway 129 in fluid communication with the chamber. A
collar 131 preferably surrounds the tip. A plurality of deflectable
locking tabs 134 project radially and proximally inward from the
collar and toward the tip. Distal ends 137 of the locking tabs
define an opening for allowing attachment of a needle assembly to
the barrel. In this embodiment, distal end 130 of tip 128 does not
extend beyond distal end 133 of the collar as it does in the
preferred embodiment of FIGS. 1-7. Having the distal end of the tip
extend beyond the distal end of the collar is preferred because it
is easier to see the tip of the barrel and to align the barrel tip
with the hub cavity for attachment of the needle assembly to the
barrel. However, this structure is preferred and not necessary to
carry out the present invention. A shorter tip may be desired for
various reasons including reducing the amount of material in the
barrel.
[0042] FIG. 9 illustrates another alternative embodiment of the
present invention. This embodiment is similar to the embodiment of
FIGS. 1-7. In this alternative embodiment, barrel 221 includes an
elongated tip 228 extending from distal end 227 of the barrel and
having a passageway 229 therethrough in fluid communication with a
chamber 223. A collar 231 surrounds the tip. A mounting element 224
is attached to the collar. The mounting element includes at least
one locking tab, and in this embodiment, a plurality of locking
tabs 234. In this embodiment it is preferred that mounting element
224 and locking tabs 234 are integrally formed of the same material
selected form the group of plastic and metal with stainless steel
being preferred. The mounting element allows for molding the barrel
with a straight collar after which the mounting element can be
attached to the distal end of the collar. In this embodiment,
deflectable locking tabs are projecting radially inwardly. They are
configured so that when the needle assembly is attached to the
barrel the hub will force the locking tabs to project radially
inwardly and proximally inwardly in an orientation similar to the
locking tabs of FIGS. 3 and 8 to prevent the removal of the needle
assembly away from the tip after attachment. In this embodiment the
locking tabs can also be positioned to project radially inwardly
and proximally before the installation of the needle assembly as
with the locking tabs of FIGS. 3 and 8. The mounting element can be
attached to the collar through various means such as adhesive,
welding and/or mechanical means such as press fitting or having
locking tabs in the mounting element which allow it to be pressed
onto the collar but not removed.
[0043] FIGS. 10 and 11 illustrate another alternative embodiment of
the present invention. This embodiment is illustrated with needle
assembly 40 which is identical to the needle assembly of FIG. 6. In
this embodiment, fluid transfer device 320 includes a barrel 321
having a chamber 323 and an elongated tip 328 extending from distal
end 327 of the barrel and having a passageway 329 therethough in
fluid communication with the chamber. A collar 331 preferably
surrounds the tip and includes a plurality of deflectable locking
tabs 334 projecting radially and proximally inwardly from said
collar. A flexible tube 370 having a proximal end, a distal end 371
and a bore 373 therethrough. The distal end of flexible tube 370 is
connected to barrel 321 so that bore 373 is in fluid communication
with said passageway. Tube 370 can be a catheter or it can be part
of an I.V. fluid administration set or various other fluid transfer
devices.
[0044] One method of manufacturing barrel 21 of the present
invention is to injection mold the barrel out of thermoplastic
material so that deflectable locking tabs 34 are projecting
radially and distally inwardly from collar 31 as illustrated in
FIG. 12. This configuration allows for easy removal of the barrel
from the injection mold. After molding, locking tabs 34 are bent
inwardly using force or heat or a combination thereof so that the
locking tabs assume a radially and proximally inwardly directed
orientation as illustrated in FIG. 3.
[0045] FIGS. 13-15 illustrate another alternative embodiment of the
fluid transfer device of the present invention. This embodiment is
similar to the embodiment of FIGS. 1-7. In this embodiment, fluid
transfer device 420 includes a barrel 421 having an elongated tip
428 extending from distal end 427 of the barrel and having a
passageway 429 therethrough. A collar 431 preferably surrounds the
tip and includes a plurality of deflectable locking tabs 434
projecting radially and proximally inwardly from the collar.
[0046] A needle assembly 440 includes a cannula 441 having a
proximal end 443, a distal end 444 and a lumen therethrough. The
needle assembly also includes a hub 447 having an open proximal end
449 with a cavity 450 therein, and a distal end 451 joined to the
proximal end 443 of the cannula so that the lumen is in fluid
communication with the cavity. Hub 447 also includes outside
surface 452. The hub in this embodiment preferably, but not
necessarily, includes projections 453 extending radially outwardly
from the outside surface of the hub.
[0047] A needle shield 480 includes an open proximal end 481, a
distal end 482 and a side wall 483 therebetween defining a cavity
484 in the shield. The cavity includes inside surface 485. The
shield is removably connected to hub 447 so that distal end 444 of
the cannula is contained within cavity 484 of the shield. The
removable connection between the shield and the hub is preferably
achieved by frictional engagement between inside surface 485 of the
shield and outside surface 452 of the hub. There are numerous ways
for removably connecting a shield to a hub including a snap-fit
arrangement or threaded engagement with the frictional engagement
described herein being merely representative of these many
possibilities, all of which are within the purview of the present
invention. The needle shield is provided to protect the cannula
from damage or contamination.
[0048] In this embodiment, hub 447 further includes means on the
hub between the distal end and the proximal end of the hub for
allowing the hub to break upon application of bending force to the
hub. In this embodiment, the means for allowing the hub to break
includes a fracturable section in the form of annular discontinuity
454 on outside surface 452 of the hub which creates a fracturable
section which will cause the hub to break upon application of force
F illustrated in FIG. 15. As indicated hereinabove, the fluid
transfer device of the present invention provides structure to
prevent removal of the needle assembly in the form of one or more
locking tabs projecting radially inwardly from the inside surface
of the collar which are adapted to engage the outside surface of
the hub of the needle assembly. This structure is provided to
prevent the improper and undesirable removal of the needle assembly
from the barrel. However, an unscrupulous healthcare worker may
attempt to apply excessive force to remove the needle assembly by
grasping the needle shield and applying a bending force which is
generally perpendicular to the longitudinal axis of the cannula in
an attempt to cause the hub to overcome the resisting force of the
deflectable locking tabs. Since substantial force can be applied it
is desirable to have a means on the hub for allowing the hub to
break upon the application of a force to the hub which is in excess
of the hub forces normally encountered during the known and proper
use of the fluid transfer device. In this embodiment, a fracturable
section is provided in the form of annular discontinuity 454 on the
outside surface of the hub. When force F, illustrated in FIG. 15 is
applied the hub will break, preferably in the area of annular
discontinuity 454. The discontinuity can, as does in this case,
produce an area of reduced cross section in the hub so that this
area is the weakest portion of the hub. The discontinuity can also
be in the shape of a sharp edge or edges which produce a stress
concentration when the hub is subject to bending. In this
situation, the result may be obtained without reducing the
cross-sectional area significantly or at all. The design would rely
on the stress concentration to promote breaking just as scoring of
a medication tablet will allow the tablet to break in half along
the score line. In this embodiment, sharp annular edge 455 is also
provided to promote a stress concentration in the area where the
hub is intended to break. Breaking in the area of the fracturable
section will cause the cannula to be safely trapped within the
needle shield and the needle assembly to be rendered non-reusable.
Also, the presence of the proximal end of the hub on the fluid
transfer device prevents the addition of a new needle assembly to
the device which could allow the undesirable second use of the
fluid transfer device. The discontinuity may be on the outside
surface of the hub or in the cavity of the hub.
[0049] Also, means for allowing the hub to break can be achieved
through the use of a brittle material in the entire hub. or in the
desired breaking area so that bending force will fracture the hub
in the area of the brittle material. This result can be achieved
using two-part or multi-part molding wherein, for example, the
proximal end of the hub is molded of a resilient plastic and the
breaking area and the distal end of the hub is molded of a brittle
plastic so that the hub will tend to break close to the
intersection of the two difference plastics where the largest
bending moment on the brittle plastic would be experienced. Since
many plastics can be formulated to exhibit a wide variety of
properties from very ductile to very brittle, the choice of a hub
material is quite broad. When using two-part molding, the plastics
should be chosen for their properties and for their compatibility
with each other at the intersection of the two plastic materials in
the hub. Polypropylene, polyethylene, styrene and polycarbonate are
preferred plastic materials for the hub. Styrene and polycarbonate
can be formulated to be very brittle and/or sensitive to surface
discontinuities and can be used for the entire hub for the part of
the hub where the fracture is desired. All of the above-described
materials and structures are within the purview of the present
invention.
[0050] It is an important feature of the present embodiment that it
provides two means for preventing the unwanted removal of the
needle assembly from the fluid transfer device. The first is the
resisting action of the deflectable locking tab or tabs against the
outside surface of the hub and the second is the fracturable
section of the hub which will cause the hub to break upon the
application of excessive force used in an attempt to overcome the
action of the deflectable locking tabs.
[0051] FIG. 16 illustrates another alternate embodiment of the
fluid delivery device of the present invention. In this embodiment,
needle assembly 540 includes a cannula 541 and a hub 547. The hub
includes open proximal end 549 with a cavity 550 therein and a
distal end 551. Needle assembly 540 further includes a fracturable
section between the proximal end and the distal end of the hub for
allowing the hub to break upon application of a bending force to
the hub. In this embodiment, the fracturable section includes an
annular discontinuity 554 in cavity 550. Annular discontinuity 554
also preferably includes sharp annular stress concentrating edge
555 to help promote breakage in the area of the discontinuity. This
embodiment, like the embodiment of FIGS. 13-15 provides two-step
protection against the undesirable removal of the needle assembly
from the fluid transfer device. The first protection is offered by
the interaction of flexible locking tabs 534 to hold the hub in its
position on projection 553. The second protection is the
fracturable section for allowing the hub to break upon the
application of bending forces on the hub in excess of those
experienced during normal proper use of the fluid transfer
device.
[0052] FIGS. 17-20 illustrate another alternative embodiment of the
present invention. In this embodiment the fluid delivery device is
syringe 620 comprising barrel 621 having a fluid chamber 623, a
proximal end 625, a distal end 627 and an elongated tip 628
extending from the distal end and having a passageway 629
therethrough in fluid communication with the chamber. A collar 631
surrounds the tip. At least one deflectable locking tab projects
radially inwardly from the collar. In this embodiment, there are a
preferably a plurality of locking tabs 634.
[0053] A needle assembly 640 includes a cannula 641 having a
proximal end 643, a distal end 644 and a lumen therethrough. A hub
647 includes an open proximal end 649 with a cavity therein, and a
distal end 651 joined to the proximal end of the cannula so that
the lumen is in fluid communication with the cavity of the hub. The
hub further includes an outside surface 652. The needle assembly is
connected to the barrel so that the elongated tip of the barrel is
in the cavity of the hub and the outside surface of the hub is
adjacent to the one or more locking tabs so that the locking tabs
prevent removal of the needle assembly from the barrel through
contact between the locking tab and the outside surface of the hub.
Locking tabs are configured to allow the assembly of the needle
assembly to the barrel through axial motion of the hub toward the
barrel.
[0054] A plunger 659 includes an elongated plunger rod 661 having a
longitudinal axis 662, a proximal portion 663 and a distal portion
664 connected by a breakable connection 668. Distal portion 664
includes a stopper 665 slidably positioned in fluid-tight
engagement with an inside surface 622 of the chamber for drawing
fluid in and out of the chamber by movement of the plunger relative
to the barrel. Stopper 665 may be a separate element connected to
distal portion 664 or it may be integrally molded with the distal
portion in a one-piece plastic construction. Separate stoppers are
preferably made of elastomeric material such as natural rubber,
synthetic rubber, thermoplastic elastomers and combinations
thereof. Breakable connection 668 is strong enough to hold proximal
portion 663 and distal portion 664 together during normal use of
the syringe and is breakable upon application of additional force
to the proximal portion.
[0055] Proximal end 663 further includes a flange 667 for applying
forces to move the plunger rod with respect to the barrel and for
breaking the breakable connection. A flange 626 is also provided at
the proximal end of the barrel to facilitate handling of the
syringe and for applying forces to the plunger using a one-handed
procedure as will be explained in more detail hereinafter.
[0056] In this embodiment, there are a plurality of breakable
connections connecting proximal portion 663 and distal portion 664.
Specifically, proximal portion 663 includes a distal projection 669
having at least one transverse protuberance projecting therefrom.
In this preferred embodiment, there are four transverse
protuberances 670. The protuberances are connected to distal
portion 664 and the breakable connection is on the protuberance. In
this preferred embodiment breakable connection 671 is on the distal
end of the protuberance. The distal projection may be circularly
shaped and fit into a cylindrically shaped recess in the distal
portion. With this structure a single protuberance extending up to
360 degrees may be used. The structure may also be reversed so that
the projection extends proximally from the distal portion toward
the proximal portion.
[0057] In this preferred embodiment, proximal portion 663 and
distal portion 664 and the breakable connections are integrally
molded of plastic material. A wide variety of plastic materials are
suitable for molding the plunger with polystyrene and polyethylene
being preferred.
[0058] The breakable connections can be anywhere along the
protuberance, at its proximal end, its distal end, or in between,
depending on, among other things, the geometry of the protuberance.
A breakable connection can also be made by connecting the
protuberance to the distal end or to the proximal end using a
frangible adhesive. The protuberance may be very short and made
entirely of adhesive or frangible material. The connection can also
be made using a shear pin passing through the distal projection 669
and distal portion 664. The shear pin may be made of plastic with
one or more notches or stress risers suitably placed to cause
breaking at the desired force levels. The breakable connection
between the proximal portion and the distal portion may also be
accomplished by using a snap-fit arrangement a portion of which is
damaged or broken when the desired force is applied. In this latter
situation, the distal portion and the proximal portion can be
individually molded and snapped together during the assembly
process.
[0059] In use, the syringe of this embodiment can be filled from a
vial, ampoule or other suitable container using known safe
procedures. An important advantage of the present embodiment is
that the plunger can be moved back and forth along the barrel as
many times as necessary to properly fill the syringe barrel. For
example, the syringe barrel may be filled with sterile water and
then the sterile water can be injected into a vial containing a
lyophilized medication which is then drawn back into the syringe
barrel. Many single-use syringes in the prior art only allow one
proximal motion of the plunger with respect to the barrel. With
these single-use syringes, once the plunger is moved in a distal
direction with respect to the barrel it can no longer be withdrawn.
Therefore, mixing sterile water and a lyophilized medication as
described above is not possible.
[0060] Another advantage of the present embodiment is that the
plunger can be moved to its distal-most position with respect to
the barrel and then moved proximally. Some prior art single use
syringes automatically lock the plunger to the barrel when the
plunger is moved to its distal-most position. These prior art
designs can lead to unintentional locking of the plunger before use
and can compromise filling and mixing procedures.
[0061] The liquid in the barrel can now be injected into a patient
or delivered in another suitable manner such as through the
pierceable septum of a catheter connector. Upon completion of the
injection the user can apply an additional force indicated as A in
FIG. 19, to the proximal portion. In this embodiment the breakable
connections are broken by the application of a distally directed
force A applied to the proximal end of the proximal portion along
longitudinal axis 662. Force A is sufficient to break the breakable
connections which causes the plunger rod to separate into two or
more unusable pieces. In this enablement the proximal portion and
the distal portion are separated as illustrated in FIG. 20.
[0062] An important advantage of the present invention is that the
breakable connection can be broken using any one-handed technique,
for example, pressing on plunger rod flange 667 in direction A with
the thumb of one hand while holding the syringe barrel and/or the
syringe barrel flange with some or all of the remaining fingers.
This is desirable over a two-handed technique wherein the barrel
must be held by one hand and the plunger by another to carry out a
breaking manipulation such as bending or twisting.
[0063] The embodiment of FIGS. 17-20 is a significant advance over
single-use syringes of the prior art. In particular, it allows
multiple strokes of the plunger with respect to the barrel without
automatically locking and rendering the syringe unusable. This
design also allows the plunger to move to its distal-most position
inside the barrel without automatically locking the plunger to the
barrel. It also provides two mechanisms to prevent or discourage
re-use. First, the needle assembly is securely locked in place so
that it cannot be removed from the barrel for improper re-use.
Second, the plunger is breakable so that its proximal and distal
ends are separated and the syringe, with the needle locked in
place, can no longer be used to inject medication. Further, the
plunger breaking feature is accomplished by a simple one-handed
procedure.
* * * * *