Note: Descriptions are shown in the official language in which they were submitted.
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LEAK PROOF TUBE CONNECTION SITE
TECHNICAL FIELD
This invention relates generally to fluidic connectors.
Specifically, the present invention relates to a leak proof
connection site for fluidic connectors that is adapted to
re-ceive different size male adapters for connection to a
tube. More particularly, the present invention relates to a
leak proof connection site that utilizes different sealing
surfaces for capping the connection site and securely
sealing the male adaptor therein without any attendant
stretching or leaking of the connection site.
BACKGROUND ART
Fluidic connectors, such as Y-site connectors and
single connectors, are well known in the art and a variety
l5 of different designs have heretofore been proposed to
satisfy the objectives of various applications. For
example, fluidic connectors are used in enteral feeding
systems where the fluidic connector acts as a connection
si-to between the feeding tube lumen and the tube assembly
leading to a patient and ensures uninterrupted fluid
communication between the feeding system and the patient
during operation.
A typical fluidic connector comprises a proximal end
connection site for fluid supply or withdrawal and a distal
end connection site for attachment to a lumen leading to a
patient. When the lumens leading to the proximal and distal
end connection sites are connected thereto, the lumens are
in closed fluid communication. The proximal end connection
site is typically a "female" connection site with a hollow
inner portion. This hollow inner portion accommodates a
"male" adaptor, through an interference fit, and provides
fluid communication with the patient lumen. Further, the
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proximal end connection site usually incorporates a closure
means where a plug tethered to the proximal end connection
site is inserted into the hollow portion of the proximal end
connection site in order to securely seal the lumen from
S fluid communication therethrough.
A fluidic connector with distal and proximal end
connection sites designed to receive a lumen which can
alternatively be plugged by a cap tethered to the connector
is described in U.S. Patent No. 5,242,389 to Schrader et al.
Schrader et al. describes a fluidic connector with a
proximal end connection site that has an inner surface
adapted to receive both a male adaptor for facilitating
attachment to a lumen as well as a plug for closing off the
connection site when the lumen is detached. However, using
the same inner surface at the connection site to receive the
male adapter and the plug suffers from a phenomena called
permanent set or plastic deformation.
A phenomena referred to as plastic deformation
synonomously known in the art as "creep" can occur in two
ways. First, if a non-conforming male adapter that is too
large is inserted into the connection site it can over-
stretch the connection site, thereby leading to a permanent
deformation of the connection site. Finally, a non-
conforming male adaptor that is left inserted into the
connection site for a prolonged period can also lead to
plastic deformation. Typically, this plastic deformation or
stretching of the connection site occurs because different
types of male adaptors are commonly used in one type of
fluidic connector with little or no conformity in size or
design of the male adaptor by vendors. Thus, a
nonconforming male adaptor is inserted into a proximal end
connection site that is ill-suited in size to accommodate
the adaptor to the extent that the adaptor begins to
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permanently stretch out the inner surface of the connection -
site over time due to its nonconforming size. Further, this
' stretching of the connection site causes the connection
site's inner surface to become unsuited for subsequent
insertion of a plug because the plug no longer securely fits
the stretched out connection site opening, thereby causing
the connection site to leak fluid even when plugged.
Accordingly, creep is responsible for a loss of sealing
function in the female when a non-conforming male adapter is _
inserted into the female receptacle for a prolonged period
of time. Creep is also responsible for a loss of capping
function because the part of the female_responsible for
capping is actually coupled to or part of the sealing
surface.
U.S. Patent No. 5,267,983 to Oilschlager et al used a
tethered cap as a strap retainer to hold the male adaptor
together with the proximal connection site in order to
ensure a secure fit with the adaptor at all times. However,
oilschlager et al did not address the attendant problem of
peaking due to stretching out of the connection site opening
since both the capping and sealing surfaces were the same
integral structure and the dimensional integrity of. the
capping surface could still be compromised when plastic
deformation occurred.
Referring to FIG. 1, a prior art fluidic connector 1 is
shown. The fluidic connector 1 comprises a wall 4 with
patient connection site 2 atthe distal end of connector 1
and a tube connection site 3 located at the proximal end of
connector 1. The tube connection site 3 is adapted to
receive a male adaptor (not shown) for facilitating
connection to a tubing assembly while the patient connection
site 2 is adapted to connect to tubing leading to a patient.
The tube connection site 3 further includes an opening
5 which leads into a cavity 6 that is adapted to receive the
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male adaptor. The cavity 6 includes a sealing and plugging
portion 7 which extends from the opening 5 to the patient
connection site 2 and is designed to form a secure - '
interference fit with the male adaptor when the adaptor is
inserted therein. The sealing and plugging portion 7 also
serves as a plugging surface wherein a cap (not shown) is
inserted through the opening 5 and engages a cap retaining
groove 8 that closes off the opening 5 from fluid
communication therethrough.
As of yet, nothing in the prior art has addressed the
problem of developing a connection site for a fluidic
connector that permits the use of various nonconforming male
adapters to facilitate connection to a lumen without
stretching out the inner surface of the connection site so
that a plug will also securely fit thereto without leakage
from the connection site.
To add complexity to the present situation, in Europe,
reversed luer tapers are used for feeding tube connections.
In other words, in Europe, the source has a female
connection. The provision of a female connection by the
source is the opposite from that used in intravenous
connections. The reasoning employed by such the European
system is that a female connection at source ehiminates the
possibility that a feeding source could be inadvertently
connected to an intravenous cannula. Therefore, any
universal fluidic connection solution to the creep problem
would necessarily require some accommodation for the
European system. Accordingly, there is not only a need in
the art to develop a connection site for a fluidic connector
that permits the use of non-conforming male adapters without
creep, but there is also a need for one or more point-of-use
adapters that would permit such a fluidic connector to be
attached to any other type of connector, such as a male luer
for the European market.
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DISCLOSURE OF INVENTION
' In brief summary, the present invention relates to a
fluidic connector with a improved connection site that
5 includes a first larger diameter portion, a second smaller
diameter portion and a deformable buckling region that forms
a part of both the first and second portions. The first
larger diameter portion forms a separate inner surface for
receiving a plug to securely seal the connection site from
fluid flow communication therethrough while the second
smaller diameter portion is adapted to receive and securely
sea-1 different sizes of male adapters for attaching a lumen.
Finally, the deformable buckling region forms a structural
buffer zone between the first and second portions that
maintains the dimensions of the first larger diameter
portion when the second smaller diameter portion is
stretched out by the adaptor due to short or long term
insertion of the adaptor therein.
Accordingly, a principal object of the present
invention is to provide a fluidic connector having a first
larger diameter portion whose dimensions and features will
not be compromised when a second smaller diameter portion is
stretched out.
Another object of the present invention is to provide a
fluidic connector with a connection site having two portions
of different diameters that are structurally distinct from
one- another.
A further important object of the present invention is
to provide a fluidic connector with smaller diameter portion
that may accommodate different types and sizes of male
adapters for insertion in an interference-type fit that
minimizes the tendency for the connection site or the
capping site to under plastic deformationand maximizes the
axial retention force of the male adaptor and cap.
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Another object of the present invention is to
provide a fluidic connector with a first larger diameter
portion that will not leak when a second smaller diameter
portion thereof is stretched out.
A further important object of the present
invention is to provide a fluidic connector with a
deformable buckling region as a buffer between the first and
second diameter portions.
These and other objects of the present invention
are realized in a presently preferred embodiment thereof,
described by way of example and not necessarily by way of
limitation, which provides for a fluidic connector with a
connection site having two portions of different diameters.
The first larger diameter portion is designed to securely
receive a plug without leakage caused by attendant
stretching of the connection site by an nonconforming male
adaptor inserted therein and a second smaller diameter
portion is adapted for securely receiving a variety of male
adapters. Finally, a deformable buckling region is provided
as a buffer between the first and second diameter portions
that maintains the shape and size of the larger diameter
portion when the smaller diameter portion is stretched out.
In accordance with a first broad aspect, the
invention provides a connection site for a fluidic
connector, said connection site comprising: an inner portion
comprising: i) a first diameter portion; and ii) a second
diameter portion adjacent to said first diameter portion,
said first diameter portion having a larger diameter than a
diameter of said second diameter portion; and a deformable
region between said first and second diameter portions
adapted to buckle for allowing said first diameter portion
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to retain the same shape when the diameter of said second
diameter portion is increased.
In accordance with a second broad aspect, the
invention provides a connection site for a fluidic
connector, said connection site comprising: an inner portion
comprising: i) a first diameter portion; and ii) a second
diameter portion adjacent to said first diameter portion,
said first diameter portion having a larger diameter than a
diameter of said second diameter portion; and a deformable
region forming a part of said first and second diameter
portions and adapted to buckle in such a manner that when
said second diameter portion stretches in a radial direction
said first diameter portion translates axially.
In accordance with a third broad aspect, the
invention provides a connection site for a fluidic
connector, said connection site comprising: an inner portion
comprising: i) a first diameter portion; ii) a second
diameter portion adjacent to said first diameter portion,
said first diameter portion having a larger diameter than a
diameter said second diameter portion; and a deformable
region forming a part of said first and second diameter
portions adapted to buckle in such a manner that allows the
first diameter portion to move axially and said second
diameter portion to stretch in a radial direction and
adapted to allow said first diameter portion to retain its
original diameter when said deformable region buckles.
In accordance with a fourth broad aspect, the
invention provides a fluidic connector comprising: a
connection site comprising: an inner portion comprising: i)
a first diameter portion; and ii) a second diameter portion
adjacent to said first diameter portion, said first diameter
portion having a larger diameter than a diameter of said
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second diameter portion; and a deformable region between
said first and second diameter portions and adapted to
buckle for allowing said first diameter portion to retain
the same shape when the diameter of said second diameter
portion is increased.
Additional objects, advantages and novel features
of the invention will be set forth in the description which
follows, and will become apparent to those skilled in the
art upon examination of the following more detailed
description and drawings in which like elements of the
invention are similarly numbered throughout.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows a cross-section view of a fluidic
connector with a prior art connection site;
FIG. 2 shows a section view of a fluidic connector
with a connection site formed in accordance with the present
invention;
FIG. 3 shows a section view of the fluidic
connector of FIG. 2 with the deformable buckling region
highlighted;
FIG. 4 is the prior art connection site of FIG. 1
showing in phantom how the connection site wall stretches
out after prolonged insertion of a male adaptor;
FIG. 5 is the connection site formed in accordance
with the present invention showing in phantom how the
deformable buckling region stretches in order to maintain
the dimensional stability of the capping portion;
FIG. 6 is a partial view of the connection site
formed in accordance with the present invention showing how
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the original dimensions of the deformable buckling region
stretch in phantom;
FIG. 7 is a section view of a fluidic connector
showing the preferred embodiment of the connection site
formed in accordance with the present invention;
FIG. 8 is a plan view of the European luer adapter
and the fluidic connector; and
FIG. 9 is a plan view of the European luer adapter
as inserted into the fluidic connector.
BEST MODE FOR CARRYING OUT THE INVENTION
Referring to FIG. 2, a fluidic connector 10 in
accordance with the present invention will be discussed.
The fluidic connector 10 comprises a tube connection site 11
at its proximal end and a patient connection site 12 at its
distal end. The fluidic connector 10 further comprises a
wall 13 that forms an inner portion shown as hollow cavity
14 inside connector 10. The hollow cavity 14 extends
between both connection sites 11, 12 and permits fluid
communication therethrough. The tube connection site 11
includes a first larger diameter portion
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15 and a second smaller diameter portion 16. The first
larger diameter portion 15 provides an area for closing off
the tube connection site 11 with a plug while the second "
smaller diameter portion 16 provides a separate surface used
for securely sealing, in an interference fit, a male adaptor
(not shown) when the adaptor is inserted into the tube
connection site-11.
The first larger diameter,portion 15 includes an
opening 17 and a cap retaining groove 18 located below
opening 17 for securely engaging the cap or plug upon
insertion of a plug (not shown) into opening 17 therein.
Although only one cap retaining groove l8,is shown, it is
within the scope and spirit of the present invention that
any suitable number of grooves 18 can be used to retain the
cap. Further, the first larger diameterportion 15 is of
sufficient diameter to allow a tight fit-for the cap, while
permitting sufficient clearance between an inner surface 23
of portion 15 and the adaptor when the adaptor is inserted
therein. Finally, the tube connection site 11 further
includes a deformable buckling region 19 that forms a
structural buffer zone between the first and second portions
15, 16.
Referring to FIG. 3, the deformable buckling region 19,
the highlighted region of FIG. 3 that overlays a zone that
partially includes both the first and second portions 15, 16
of the tube connection site 11 where the two portions 15, 16
join. Specifically, the deformable buckling region 19 is
the area-beginning at an outer annular ridge 20 and ending
where a curved portion 21 of the tube connection site 11
terminates. The outer annular ridge 20 serves to maintain
the radial dimensional integrity of the first larger
diameter portion 15 and provides termination of the buckling
zone.
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Referring to FIGS. 4 and 5, the operation of the
deformable buckling region will be explained. As seen in
FIG. 4, the original configuration of the prior art fluidic
connector 1 before plastic deformation occurs is shown in
solid while the configuration of that same connector 2 after
the sealing and plugging portion 7 have been stretched out
is shown in phantom. Without the deformable buckling region
19, the entire length of the sealing and plugging portion 7
is subject to stretching out. Leakage occurs when the
1D opening 27 is plugged because the same surface is used to
both plug the tube connection site 11 as well as to form a
seal against the male adaptor. Thus, when a nonconforming
male adaptor is inserted into the tube connection site 11
for a prolonged period, the entire length of the sealing and
plugging portion 7 is stretched out permanently in a radial
direction, denoted as direction A in FIG. 4. This radial
displacement of the wall 13 creates a larger diameter _ ._
aperture at the opening 17. Radial displacement of opening
17 also results in an attendant loss of axial retention
2o force when a plug is used to seal off the tube connection
site 11 since the plug no longer securely fits the opening
27.
Referring to FIG. 5, the fluidic connector 20 of the
present invention is shown. The original configuration of
the fluidic connector 10 before insertion of a male adapter
into the smaller diameter portion 16 is shown in solid,
while the configuration of the connector 10 after plastic
deformation has occurred is shown in phantom. When the tube
connection site 21 is subjected to plastic. deformation, the
second smaller diameter portion 16 is stretched radially or
in the A direction, the deformable buckling region 19
deforms, with the deformation terminating at the outer
annular ridge 20 and possibly resulting in translation of
the first larger diameter portion 15 axially without
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affecting the size and shape of the larger diameter portion
with respectto it's plugging function.
Referring to FIG. 6, an enlarged view of the fluidic '
connector 10 with the deformable buckling region 19 is
5 shown. In. the preferred embodiment, a male connector (not
shown) is inserted into the second smaller diameter portion
16, expanding portion 16 radially in the A direction.
However, the buckling or unwrapping effect of the deformable
buckling region 19 allows the portion of the first larger
10 diameter portion 15 that is adjacent to the deformable
buckling region 19 to be isolated from forces that would
expand it radially, even in the absence of an outer annular
ridge 20. However, the addition of one or more annular
ridges 20 will further isolate the first larger diameter
15 portion 15 from any forces which might expand it radially.
The axial component of the deformation of the deformable
buckling region 19 can result in a change in the overall
length of the first larger diameter portion 15, either
longer or shorter, depending on the specific configuration
of the deformable buckling region 19. The net effect of
this change in length, which is shown in phantom in FIG. 6,
is an axial translation of the first larger diameter portion
15 relative to the rest of the connection site. 11.
Referring to FIG. 7, the preferred enbodiment of the
present invention is shown. The preferred embodiment
consists of a Y-Site connector 110 comprising a tube
connection site 121 at the proximal end of connector 110, a
patient connection site 112 at the distal end of connector
210, and a flushing port 11.4 at the midpoint along connector
110 which is set at an angle in relation to the tube
connection site 111. Further, the tube connection site 111
has a male adaptor 113 inserted therein for connection to a
lumen (not shown) while the patient connection site 112 is
adapted to receive a barbed connector 115 for attachment to
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a lumen (not shown) leading to a patient. The Y-Site
connector 110 also includes a cap 116 tethered to the tube
connection site 111 by an arm member 117 and is used to plug
the opening 118. Finally, a luer taper adaptor 120 in
combination with a flushing port cap 121 is tethered to the
flushing port 114 by a flushing port arm member 119. The
tube connection site 3.11 further includes a first larger
diameter portion 122 and a second smaller diameter portion
123 with a deformable buckling region 124 overlaying parts
of both portions 122, 123 where portions 122, 123 join. The
deformable buckling region 124 includes an outer annular
ridge 125 and a curved portion 126 and functions in the same
manner as explained above by acting as a buffer for the
first larger diameterportion 122.
Referring to FIG. 8, a fluidic connector is shown
generally at 130. Fluidic connector 130 is preferably
identical to or similar to ~luidic connector 10 or Y-site
connector 110. Above fluidic connector 130 is a luer adapter
shown generally at 132.
Luer adapter132 comprises male-to-male luer 134,
optional luer skirt 136 disposed on male-to-male luer 134,
tether-138 disposed at one end on male-to-male luer 134, and
luer cap 140 disposed at the other end of tether 138.
Optional leer skirt 136 has internal threads (not shown) and
is disposed on a hub portion 142 of male-to--male luer 134
and retained by enlarged portions 144 (only one side shown)
of male-to-male luer 134. One end of tether 138 is also
disposed an a hub portion 142 of male-to-male leer 134. The
other end of tether 138 retains luer cap 140. Luer cap 140
has an external thread146 which is adapted to engage the
internal threads of luer skirt 136. Male-to-male luer-134
itself is made from and has a graduated tube portion 148, a
rib portion 150 wherein a plurality of gripping ribs 152 are
provided to assist in providing a reliable connection with
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fluitlic connector 130, a flange 154, an assembly-retaining
area 156, and a male connector 158 for connecting to a
female source.
Referring to FIG. 9, luer adapter 132 is shown fully
inserted into fluitlic connector 130. In operation, leer
adapter 132 is inserted into fluitlic connector 130 to permit
male connector 158 to be presented to a female source (not
shown). The interior of fluitlic connector 130 is internally
graduated to accommodate various sizes of male connectors.
Graduated tube portion 148 of luer adapter 132 as shown has
two different diameter portions adapted to the internal
graduations in fluitlic connector 130 to provide a reliable
seal between the adapter 132 and the connector 130. When
luer adapter 132 is fully inserted into fluitlic connector
130, a plurality of ribs 152 present an increasing outer
diameter to meet the internally graduated fluitlic connector
130. The plurality of ribs 152 are adapted to present a non-
continuous circular surface area of contact to the interior
of fluitlic connector 130. The surface area presented helps
prevent creep or plastic deformation in fluitlic connector
130, but is adequate to permit a reliable friction fit. It
is also preferred that a redundant seal system which
prevents fluid leakage or introduction of foreign matter
into adapter 232 is preferred. Accordingly, flange 154 of
luer adapter 132 provides a function similar to a cap to
seal the unfilled remainder of the opening of fluitlic
connector 130 and held in place by friction fit between the
inner portion of the opening of fluitlic connector 130 and a
downwardly extending cylindrical portion 155 of-flange 154.
Once sealed, a -cap portion 160 for closing the opening of
fluitlic connector may be cut off or otherwise removed.
Initial results obtained in accordance with the present
invention show that all adapters tested above 17,593 kg/m2
{25) psi over a thirty day pressure leak test, which exceeds
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by over three times the specification requirement of 5630
kg/m2 (8 psi). In addition, the pull force required to
remove the luer adapter 132 from fluidic connector 130
ranged from above 4.54 kg to 6.81 kg (10 pounds to 15
pounds) on average, which surpasses the typical pull force
requirement of 5 pounds for solvent bonded connection in
Dobhoff feeding tubes.
Although particular embodiments of the invention have
been shown, it is not intended that the invention be limited
thereby, instead the scope of the present invention is
intended to be limited by the appended claims.
