Note: Descriptions are shown in the official language in which they were submitted.
CA 02443243 2005-03-16
NON-REMOVABLE CONNECTOR FOR PATIENT FLUID
COLLECTION SYSTEM
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to non-refluxing suction canister systems and
components therefor, and more specifically to such systems having canisters
closed by anti-refluxing valves or which have flexible liners.
Related Art
During operative surgery and other medical and biological procedures,
suction canister systems are used to collect fluids from a patient, including
blood,
saline, and any other fluids which may accumulate or must be removed and
contained during the procedure and disposed of after the procedure. The
collection system uses suction canisters and a vacuum source. While a single
canister can be and are often used, a multiple canister suction system will be
described because the use and operation of a. single canister system is
apparent
from that for a multiple system. Multiple canisters are arranged in tandem
with a
first canister having a suction tube to collect fluids from a source and to
deposit
the fluids in the first canister. Downstream ~~anisters are coupled together
with
their vacuum sources applied in series or in parallel from a vacuum source
connected at the end canister.
Typically, a canister unit includes an open-top cylindrical canister closed
by a cover or lid to which is sealed an internal liner to be contained in the
canister.
Vacuum is applied through the canister wall to the space or cavity between the
liner and the canister wall to expand the liner outwardly toward the canister
wall.
Vacuum is also applied for each canister to a vacuum port in the lid to
develop a
subatmospheric pressure or vacuum within the liner, which vacuum then also
develops at the collection tube at the desired level. Tandem tubes connect the
interior of the liner of the first canister to the: inlet
CA 02443243 2004-10-26
2
port on the lid of the next succeeding canister so that when the first
canister fills,
fluid in the first canister thereafter passes to the second canister, and so
on.
The lid typically includes several access ports with associated attachment
or connection elements. A vacuum port accepts a tube from the vacuum source
to apply vacuum internal to the liner. An inlet or patient port accepts one
end of
the suction tube. A large access port is typically capped until a fluid
setting
agent such as IsolizerT~ is bo be added. An outlet or "ortho" port includes a
wider riser portion than the patient port for connection of a suction tube
during
orthopaedic operations or for connection of a tandem tube for connecting an
additional collection canister to the fast. The vacuum port of each catrist~
includes a float valve to prevent withdrawal of fluids into the vacuum system.
However, the other ports in the lid which are exposed to the fluids lack any
valve
and are subject to reflex and may lead to contamination of personnel or a
working area.
In situations where one or more canisters.become filled before the end of
the procedure, fluids may reflex or come out of one or more ports under
certain
circumstances. For example, if vacuum is removed from the system, the
pressure differential betweea atmosphere on the one hand and the cavity
beriveen
the canister and the lining on the other, crated by the vacuum between the
canister and the liner, is removed. Removal of the vacuum allows the liner to
collapse somewhat, due to liner elasticity, increasing the internal pressure
on the
fluid inside the liner. This increase pressure could cause fluid to be pushed
out
through the suction tube toward the patient or otherwise out the collection
tube.
Fluid may also be pushed out the port for the tandem tube toward a secondary
canister. When the interconnected canisters are disconnected, fluid may be
ejected from the leaden tube, thereby possibly contaminating surface or
personnel.
As a further result of the inaease liner pressure difl~tial, the canister
liner may still be sufficiently enlarged or inflated to remain in contact with
the
walls of the canister, making it difficult to withdraw the lid and. liner from
the
canister, for the similar reason as it is difficult to remove a filled plastic
bag
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3
from a trash can. To remove the lid and liner, personnel often try to
manipulate
the lid and liner either by grasping the liner or grasping fittings on the lid
to gain
an advantage in forcibly removing the lid and liner from the canister. Such
manipulation often puts pressure on the liner thereby increasing the tendency
of
S the liner to eject fluid, and also places force on the fittings which could
cause -
removal of caps on fittings or breakage of fittings, cormections or caps. Each
of
these could cause contamination through ejection of fluids.
As long as vacuum is applied to the system, equilibrium exists throughout
the system. However, once vacuum is removed or once vacuum is removed end -
personnel attempt to dismantle the system to dispose of the filled linefs, the
possibility of contamination increases. There exists, therefore, a need for a
system which further minimizes the possibility of loss of fluid or
contamination
in vacuum collection systems.
SUI~'IMARY OF THE INVENTION
The present invention provides a fluid collection system which minimizes
the possibility of contamination through fluid reflux of collected fluids,
which
simplifies assembly of fluid collection systems, improves the integrity of
individual fluid collection canisters in a system, and which improves the
breakdown procedure for dismantling vacuum canister fluid collection systems
for disposal. In accordance with the present invention, a fluid collection
system
includes a fluid collection reservoir, a cover and a liner within the
reservoir
comprising an enlargable or expandable wall portion such that the wall portion
may expand if the liner fills with fluid. Such a fluid collection system makes
~
significant use of the pre-existing configuration of a suction canister
system,
especially a system which has at least one of the canisters filled with fluid,
by
taking advantage of the pressure characteristics of such a system, both while
the
vacuum is applied and after vacuum is removed. For example, after a particular
liner has become filled, the pressure differential within the liner is
increased
relative to the canister and to atmospheric pressure when vacuum is removed.
The inherent elasticity of conventional liners maintain that pressure
differential,
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4
when the seal between the lid and the canister is broken and the lid and liner
combination removed. By contrast the new liner is allowed to expand,
preferably outward of the canister, while still retaining the contained fluid,
thereby reducing the pressure differential between the fluid and atmospheric
to
approximately zero. Thereafter, the fluid inside the liner is no longer
"pressurized" and can be handled in accordance with standard procedures. In
one particularly beneficial form of the invention, the enlargable or
expandable
wall portion of the liner is formed from bellows or accordion-type folds or
pleats
formed in the liner adjacent the cover, so that a given fold extends
circumferentially around the liner. Preferably, multiple folds are similarly
arranged and distributed with respect to each other axially so that the lid
can
move upward away from the bottom of the liner as the liner expands.
In a further preferred form of the invention, the seal between the canister
and the lid is formed such that the seal is maintained while vacuum is applied
between the canister wall and the liner but whereby the connection between the
lid and the canister is broken when the liner is full and the vacuum removed,
thereby allowing the lid to lift off of the canister and the liner to expand
to
decrease the pressure differential between the liner and atmosphere.
In one preferred embodiment, the folds or pleats are formed so as to
permit approximately one-fifth again as much volume to be created in the liner
as
the folds expand, compared to its unexpended volume. Such an arrangement
accounts for any additional volume of fluid which might otherwise be expelled
in
conventional liners due to the pressure differential, as well as any
additional
material which may be added to the liner for solidifying its contents.
In another form of the present inventions, a fluid suction canister system
is provided with a one-way valve in the port for the fluid coming into the
canister so as to allow fluid into the canister but to prevent fluid from
exiting the
canister through the port. Such a one-way valve would prevent reflux, of fluid
in the tube, along the collection tube as well as preventing reflux of fluid
out of
the liner through the port. In one preferred embodiment, the valve is a
flapper
valve.
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In a further form of the inventions, a fluid collection system is provided
which includes first and second fluid collection reservoirs, a fluid conduit
connecting the first and second reservoirs and a one-way valve in the conduit
for
allowing fluid flow in the conduit, for example when the conduit is attached,
and
5 preventing fluid flow out of the conduit when the conduit is removed from
one of
the reservoirs. Such an arrangement is particularly suited to the tandem tube,
so
that no fluid is lost from the tandem tube when it is disconnected from one of
the
canisters. In the preferred embodiment, the tandem tube is to be removed from
the downstream canister, and the valve is placed in the tandem tube at the
connector with the downstream canister. In a further preferred embodiment, the
downstream canister also has a one-way valve, such as that described above, in
the lid of the canister. In a still further preferred embodiment of the
invention,
the opposite end of the tandem tube is non-removable from the first canister
so
that the tandem tube cannot be removed inadvertently from that canister, and
so
that a tandem tube remains with a full liner, to be properly disposed.
Alternatively, the tandem tube can include valves at each end of the tube. In
a
still further preferred form of the invention, the valve at the end of the
tandem
tube is held open when it is connected to the downstream canister and closes
to
seal the tandem tube as the tandem tube is being removed for the downstream
canister.
In another form of the inventions, a female connector is provided having a
sealing element wherein the connector attaches to a male connector portion
having a cross-sectional configuration conforming to a portion of the sealing
element. The connector includes a connector housing, a female mating portion
in the housing having a wall defining an opening for accepting the
corresponding
male connector portion and wherein the wall begins at an entrance to the
connector and terminates at an end wall. A flexible wiper seal is provided
internal to the entrance to the connector and includes a wall defining an
opening
smaller than the dimension of the female portion for engaging and preferably
conforming to the outside wall of the male portion when the female portion and
the male portion are mated. This connector is particularly suited to the
tandem
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tube connector for the connection with the downstream canister. The flexible
wiper seal preferably is formed from a rubber or other flexible material
having
an opening smaller than the male portion so that the wiper seal contacts and
slides along the surface of the male connector portion to minimize the
possibility
of leaving fluid on the male connector portion, since the male connector
portion
is exposed after the tandem tube is removed, and prior to being capped.
In another form of the inventions, a non-removable connector is provided
for connecting a first element, such as the tandem tube, to a second element,
such as the outlet port in the upstream canister lid. The port has a wall
defining
an opening in the second element into which the connector is to be mountedT
wherein the wall includes an external opening and a known length toward the
opposite end of the wall from the opening. The connector has a body which
includes a proximal stop surface for limiting the distance the connector can
pass
into the opening. A plurality of legs extend distal of the stop surface to
pass into
and through the opening when the connector is connected to the second element.
Outwardly extending catches are formed on a plurality of the legs having
proximately facing ramp surfaces, such that when the connector is engaged in
the
opening and a withdrawing force is applied to the connector, the ramps engage
the end wall and so that the legs are caromed inwardly into the opening until
at
least two of the legs contact each other to prevent further withdrawal of the
connector. This connector is particularly suited to the tandem tube where it
is
desired to keep the upstream end of the tandem tube permanently connected to
the lid of the upstream canister. In one preferred form of the invention, the
mating portion of the connector includes four evenly and circularly
distributed
legs extending into the opening of the tandem port on the upstream canister.
The
outwardly extending catch on each leg engages the end wall to keep the
connector from being removed. However, since the legs can be moved inwardly
toward each other relative to the wall of the opening, the proximally facing
ramp
surfaces on the first two oppositely disposed legs are caromed inwardly if a
removing force is applied to the connector such that the connector moves
slightly
outwardly relative to the port. By the caroming action, the first two
oppositely
r sir r .m ~~~ y,en.n.~rri~b.r:l .r..N.w~~..-0*~~n..:.rv.r..nlil~
CA 02443243 2004-10-26
facing legs move inwardly toward each other and, preferably, contact, while
still
engaging the wall. While in contact, the adjacent second pair of legs cannot
move
inwardly suffciently enough to disengage from the wall. As a result, all four
outwardly extending catches remain engaged with the wall, preventing removal
of the connector from the port. In a further preferred embodiment, the catchy
on
the first, tamped legs extend outwardly somewhat further than the catches on
the
second legs.
It is therefore an object of an affect of the present invention to provide an
improved vacuum canister fluid collection system which further minimizes the
possibility of contamination by collected fluids.
It is a further object of an aspect of the present invention to take
advantage of the inherent pressure characteristics of pre-existing systems to
improve the integrity of the system and of the individual fluid collection
canisters
and their components.
It is another object of an aspect of the gresent invention to provide a
vacuum canister fluid collection system having a liner with an enlargeable or
expandable wall portion to decrease any possible pressure differential within
the
liner after vacuum is removed from the system.
It is a still further object of an aspect of the present invention to provide
a
vacuum canister fluid collection system which minimizes the possibility of
reflux
or ejection of collected fluids during and aRer disassembly of the system.
In accordance with an aspect of the invention, a non-removable connector
for connecting a first element to a second element having a wall defining an
opening in the second element into which the connector is to be mounted
wherein
the wall includes an external opening and an end wall opposite the external
opening forming a known length between the end wall and the opening, the
connector comprises:
a connector body having a proximal portion and a distal portion;
a stop on the body between said proximal and distal portion for limiting
the distance the connector body can pass into the opening;
,. .....~..-...".*, , .~.w...",.~...~."~-,"
CA 02443243 2004-10-26
7a
a plurality of legs on the distal portion to pass into the opening when the
connector is connected to the second dement; and
outwardly extending catches on a plurality of the legs having proximally
facing ramps, such that when the connector is engaged in the opening and a
withdrawing force is applied to the connector, the ramps engage the end wall
and
are cammed inwardly into the opening until at least two of the legs contact
each
other to prevent further withdrawal of the connector while the ramps still
engage
the end wall.
In accordance with another aspect of the invention, a fluid conduit for
connecting first and second fluid collation reservoirs, the fluid conduit
comprises:
a fluid flow conduit having first and second ends;
a non-removable connector coupled to the first end and comprising:
a connector body having a proximal portion and a distal portion;
a stop on the body between said proximal and distal portion for
limiting the distance the connector body can pass into the opening;
a plurality of legs on the distal portion to pass into the opening
why the connector is connected to tire second element, and
outwardly extending catches on a plurality of the legs having
proximally facing ramps, such that when the connector is engaged in the
opening
and a withdrawing force is applied to the connector, the ramps engage the end
wall and are cammed inwardly into the opening until at least-two of the legs
contact each other to prevent further withdrawal of the connector while the
ramps
still engage the end wall; and
a female valve and connector combination coupled to the second end, the
female valve and connector combination comprising:
a connector housing;
a female mating portion in the housing having a wall defining an
opening for accepting the corresponding male connector portion, the wall
beginning at an entrance to the connector and terminating at an e~ul wall, and
.,. , ., " .._.."".."".,.w,",a.,~"._..,".~.,
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7b
a flexible wiper seal internal to the entrance to the connector and
including a wall defining an opening smaller than the dimension of the opening
of the female portion for engaging the outside wall of the male portion when
the
female portion and the male portion are math.
These and other objects of aspect of the present inventions will be
demonstrated by the drawings and the detailed description of the preferred
embodiments, which follow.
BRIEF DESCRIPTION OF THE DRAW>QVGS
l0 FIG. 1 is side elevation view of a vacuum canister fluid collection system
for use with the present invention.
FIG. 2 is a perspective view of a canister for use with the fluid collection
system of the present invention.
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FIG. 3 is a top plan view of a lid for use with a canister such as shown in_
FIG. 2.
FIG. 4 is a partial vertical section of the lid of FIG. 3 taken along lines 4-
4 showing the vacuum port and patient port.
FIG. 5 is a cross-section of a patient valve with the lid in accordance with
one aspect of the present invention.
FIG. 6 is a plan view of a flapper valve for use with the patient port.
FIG. 7 is a cross-sectional view of the lid flapper valve of FIG. 6.
FIG. 8 is a cross-sectional view of a retainer for the lid flapper valve of
FIG. 6.
FIG. 9 is a view of a tandem tube in accordance with a further aspect of
the present invention.
FIG. 10 is a longitudinal cross-section of a tandem tube valve in an
exploded configuration.
FIG. 11 is a cross-sectional view of the tandem tube valve of FIG. 10 in
assembled form.
FIG. 12 is a tandem tube valve in place on the patient port of a
downstream canister with the flapper valve held open by the patient port on
the
downstream lid.
FIG. 13 is a cross-sectional view similar to that of FIG. 12 showing the
tandem tube partially removed from the patient port and showing the flapper
valve partially closed and the wiper valve contacting the wall of the port.
FIG. 14 is a cross-sectional view of the tandem tube valve similar to that
of FIG. 12 with the valve being further removed and the wiper valve in contact
with the mating port.
FIG. 15 is a longitudinal cross-section of a tandem tube connector.
FIG. 16 is a further cross-section of the tandem tube connector rotated
about a longitudinal axis approximately 90 degrees from the view shown in
FIG. 16.
FIG. 17 is a bottom plan view of the tandem tube connector.
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FIG. 18 is a cross-sectional view of the tandem tube connector attached to
a canister lid through a tandem tube port.
FIG.19 is across-sectional view of a pleated liner for a canister is
accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the present invention, a fluid collection system is
provided which takes full advantage of pressure differentials created in the
fluid
collection system to increase the integrity of the system and its component
part,
and to reduce the possibility of contamination through fluid loss or reflex.
The
systtm of the present inv~tion provides a more sectn~e system and provides Gd
and liner combinations which are more easily neutralized and disposed of.
In accordance with the present invention, a vacuum canister fluid
collection system 40 (FIGS.1 and 2), and as may be used for collecting fluids
from patients or other sources during operations, medical procedures or other
uses, includes a vacuum source such as pump 42 and a collection tube 44 for
collecting fluid from the patient or other source. The collection tube is
coupled
to the patient port 46 in a first vacuum canister 48, described more fully
below.
The first canister 48 is fluidly coupled to a second canister 50 through a
tandem
tube 52. The vacuum put 42 is also coupled to a vacuum port 54 on the
second canister 50 for providing the raluired pressure differential, as is
known to
those skilled in the art. Additional suction canisters may be provided as
necessary. The vacuum may be applied to the canisters in series or in
parallel, as
is also known to those skilled in the art. Either arrangement is equally
applicable
to the present inventions.
In the preferred embodiment, vacuum is also applied to the canister
through the canister wall 56 through a vacuum attachment 58 mounted to the
outside of the canister.wa>). Such a configuration is commonly used with the
Baxter Medi-Vac'~'M CItD flex canister system whereby vacuum is applied to the
canister through the vacuum attachment 54 and also to the interior of the
liner
through the vacuum port 54.
CA 02443243 2003-10-08
Each canister includes a flexible liner CO fixedly and fluidly scaled within a
circular groove formed in the bottom of tile lid (12 so that the lid and the
liner form a
complete and closed container, except for the ports described more fully
below. ~fhe
Tiller preferably includes an enlargcable or expandable wall portion 6~ which
(FIG.
S 1~)) can expand if the liner fills with Iluid such that the cfTective intel-
Ilal volume of
the liner can increase;. Referring to Figure 19, the liner 60 within the
reservoir has a
longitudinal length extending (i-om the upper liner portion Gl to the lower
liner
portion 63 and comprises a substantially longitudinally noncxpandable sidcwall
portion GS that remains substantiLllly uncxpanded when the liner f~0 is filled
with fluid.
This nonexpandable sidewall portion (>S has a length, extending in the same
direction
as the liner length, which is less than the IOllgltlldlilal lellgtll Of the
Tin L:r and which is
substantially the same before and after the liner fills with Iluid. 'rhe liner
O) furtllcr
comprises a substantially longitudinally expandable sidewall portion (i4 that
may
expand if the liner fills with fluid. This expandable sidewall portion (i4 has
a length
1 S lacfore the liner fills with fluid that is Icss than an expanded length
after the liner tills
w'lth flLlld. wlth t111S COnfl~Llr2lllOtl, the llnel' Wlth all Llllexl)allded
bllt expalldable
section preferably f01'IlIS the standard volume for receiving Iluid, for a
given canister
size. If the liner tills with fluid to the standard full volume, the
expalldablc portion O4
can then expand to effectively increase the total volume of the liner. The
liner GO is
able to initially take a first relaxed shape wherein the liver sidcwall
extends to the
bott0171 portion sufficiently so that the bottom portion is adjacent the
container bottom
portion. 'then when the removable lid is removed from the container, the liner
is able
to take, a second expanded shape extending through the: opening of the
container. 'hhe
increased volume preferably reduces any di('ferential pressure between the
interior of
2S the 1111111~~ and ambient pressure when vacuum is removed li-om the system.
The
increased liner volume also permits addition of other fluids or materials,
such as
solidifying agents for the fluid.
In the preferred embodiment, the expandable wall portion is formed front a
series of pleats or bellows. Prclc.rably, each pleat is fonlled
circumlerentially around
s0 the entire circumference of the liner at a location near or adjacent the
lid. The series
of pleats arc preferably formed axially with respect to each other so that the
wall
CA 02443243 2003-10-08
l0a
portion of the liner can expand or enlarge axially or longitudinally to
relieve any
pressure differential that may exist when the system is dish Mantled.
Circumferential
pleats are preferred over longitudinal pleats because longitudinal pleats may
expand
even while vacuum is present in the canister and may make it more difficult to
remove the liner from the canisti:r.
In the preferred embodiment, for a 3000 ml canister, the enlargcable wall
portion may permit addition of 4()0-O00 mls of volume; to the liner. It has
been found
that the pressure differential of conventional liners could result in rellux
of
approximately 25(.) ml of fl id at maximum vacuum. By providing ahout one-
fifth or
one-sixth again as much additional volume, the additional liner volume may
accommodate the pressure differential, as well as accommodate addition of
materials
for soliditying or otherwise neutralizing the fluid.
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Preferably, the pleats are uniform and extend completely around the
circumference of the liner, for each pleat. The pleats preferably have a wave
length of approximately 0.166 inch, each crest having a preferred radius of
approximately 0.015 inch and each trough, extending inward relative to the
liner,
S having a preferred radius of approximately 0.030 inch for a typical liner
wall
thickness of 0.010 inch.
In operation, vacuum is applied to the cavity or spacing between the
canister wall and the liner, and the lid is held in place on the rim of the
canister
to form an appropriate seal, as is known to those skilled in the art. With the
evacuation of the cavity between the liner and the canister walls, the wall of
the
liner expands flexibly outward into contact with the canister wall to provide
a
portion of the vacuum for suction and to preclude collapse of the liner wall,
as is
also known to those skilled in the art. The vacuum system pulls fluid into the
interior of the liner through the patient port 46 (FIGS. 3 and 4) and into the
volume defined by the liner (FIG. 2). When the liner is full, a conventional
float
valve 70 attached to the bottom of the vacuum port 54 closes, removing vacuum
to the interior of the liner from that port. Thereafter, continued suction
results
from vacuum applied to the liner in the second canister, which then brings
fluid
from the liner in the first canister out through the tandem port 72 through
the
tandem tube 52 and into the liner of the second vacuum canister 50 (FIG. 1)
through its respective patient port 74.
When the operation or procedure is complete, the tandem tube is removed
from the second canister 50, the vacuum tube is removed from the vacuum port
on the lid 62, and also from the vacuum attachment 58. The vacuum port and
the other ports on the lid 62 are capped (not shown), as is the free end of
the
tandem tube. Upon removal of a vacuum from the vacuum attachment 58, the
pressure differential between the liner and the canister walls approaches
zero, in
other words the pressure in the cavity approaches ambient pressure. Because of
the earlier vacuum, and influx of fluid into the liner, the fluid pressure
within the
liner exceeds ambient pressure. This resulting pressure differential exerts an
expansive force on the liner and lid. Any expansive forces in the radial or
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12
downward direction are retained or contained by the canister wall and bottom
surface. However, the only element containing the pressure against the lid is
any
seal or interference snap fit which may exist between the lid and the rim of
the
canister after vacuum is removed. The pressure differential is sufficient to
break
the lid-rim connection; and the internal fluid pressure within the liner
presses
against the lid and creates a force expanding the pleats, with a resultant
increase
in liner volume, which is accommodated by movement of the lid upward away
from the rim of the canister. Expansion continues until the internal pressure
of
the fluid is counterbalanced by the return force provided by the flexible
material
of the liner. It has been found that :ire internal liner pressure is
sufficient after
removal of the vacuum to force the lid off of the rim of the canister to allow
the
Liner to continue to expand upwardly. It has also been found that the
conventional lid design was sufficient to permit the lid to lift off of the
rim,
without redesign. However, it was also found that the five clips or bumps
evenly distributed about the internal circumferential wall of the lid needed
to be
moved downward, as viewed in FIG. 4, because repeated flexing of the original
lid with vacuum caused the clips to gradually walk up the rim of the canister.
The clips were also enhanced to give more of a snap action.
In the preferred embodiment, the patient port on the Lid 62 is preferably
enlarged to be approximately the same size as the preexisting "ortho" port
used
with orthopaedic surgical applications. The patient port well 76 is also
enlarged
to accommodate the larger port cone or riser and connectors, as necessary. The
patient port riser may accommodate elbow adaptors and other connectors, as is
known to those skilled in the art.
The patient port, in accordance with a further aspect of the present
invention, includes a one-way valve 78 mounted to the underside of the lid 62
to
allow fluid into the liner and to prevent fluid from exiting the Liner through
the
patient port (FIGS. 5-8).
As shown in FIG. 5, the patient port is slightly tapered to a narrower
opening for accepting the collection tube 44, in the case of the first
collection
canister, or for accepting the tandem tube valve in the case of the second or
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13
other vacuum canisters. A circular wall 80 extends downwardly from the
underside of the lid to the interior of the liner for accepting, on the
outside
thereof, a flapper valve housing 82 and for accepting, within the interior
thereof,
a flapper valve 84. The flapper valve (FIGS. 6 and '~ is preferably a unitary
polyisoprene material having an outer ring 86 surrounding an inner moveable
valve element 88 substantially in the shape of a circle except for a web 90
connecting the valve element 88 to the outer ring 86. The outer dimension of
the
valve element 88 is less than the inner dimension of the outer ring 86 so as
to
form a space for permitting movement of the valve element and fluid flow
through the outer ring 86.
The flapper valve housing 82 (FIG. 8) is preferably cup-shaped with a
circular opening 92 through which the valve element 88 can extend to permit
fluid flow through the flapper valve and into the interior of the liner. The
housing 82 fits over and around the downwardly extending wall 80. The fit is
facilitated by a chamfer. The radial portion of the housing includes a weld
ring 96 extending upwardly toward the circular wall 80.
The flapper valve prevents reflux of fluid from interior to the liner along
the passageway of the collection tube 44. Additionally, the flapper valve
inhibits
fluid flow through the collection tube when the valve is closed, such as after
the
vacuum has been removed. As a result, reflux of fluid from the open end of the
collection tube is minimized. The wider patient port permits use of the fluid
collection system in orthopaedic as well as other surgical and medical uses
without having to go to another system. The larger port permits easy passage
of
particulate material which may be passing through the collection tube 44.
In the preferred embodiment, the other side of the patient port includes an
annular groove 98 having an inside wall equal to or slightly smaller than the
outer dimension of the moveable valve element 88, to ensure proper seating of
the valve element against its seat.
In the use of a single suction canister, the tandem port is securely capped
to prevent any fluid leakage out the tandem port. What was conventionally the
orthopaedic port has been modified to form the tandem port, approximately the
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14
same diameter as the inlet or patient port, but having a shorter tapered cone
than -
was ordinarily used with the orthopaedic port. The inside diameter of the port
is
slightly larger to accept the tandem connector, when used, to fix the tandem
tube 52 to the lid. The opposite end of the tandem tube is mounted with the
tandem valve, described more fully below.
The tandem tube 52 includes a flexible tube 100 mounted to the tandem
connector 102 through an interference fit over ribs 104 (FIGS. 15 and 16). The
interference fit is sufficient to prevent removal of the tube from the
connector by
hand. The tandem connector 102 includes wings 106 to serve as a stop to
prevent the connector from being inserted in;o the tandem port further than
the
stop and also to provide a surface for applying pressure on the connector to
press
it into the tandem port. The tandem tube connector has a body 108 preferably
cylindrical in general outline with one or more circumferential ridges or
coupler
rings 110 to form a seal between the tandem connector body and the interior
wall
of the tandem port when the connector is fully seated in the port. The lower
portion of each ridge 110 slants upwardly and outwardly from the body to a
flat
circumferential wall 114 which engages the interior wall of the port. Each
ring
terminates at a flat surface 116 extending from the circumferential wall 114
back
to the body 108. The distal-most ring includes an outwardly extending
flange 117 extending circumferentially around the proximal-most portion of the
wall 114. Below the lower-most ring 110, a semicircular ring 118 for strength.
The distal or innermost portion of the tandem connector body 108
terminates in a plurality of legs 120 for passing through the tandem port when
the connector is connected to the tandem port. Preferably, four equally,
circumferentially spaced legs are positioned around and form the inside
terminal
end of the tandem connector. Each leg has a preferably uniform wall thickness
except for outwardly extending catches or locks, the first two of which locks
122
are shown in FIG. 15 on the first pair of legs and the second two of which
locks 124 are shown in FIG. 16 on the second pair of legs. The locks 122
and 124 extend outwardly to engage the inner-most rim of the tandem port,
which rim 106 extends downwardly from the underside of the lid 62 (FIG. 18).
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Each lock includes a guide surface 128 for pushing the legs inward through the
action of the outer rim of the tandem port when the tandem connector is first
inserted into the tandem port. Each guide 128 terminates in a radially
inwardly
extending locking surface. The locking surface for the first ramp locks 122
are
5 camping or caroming surfaces 130 extending radially inwardly and downwardly
toward the body of the tandem connector. The locking surfaces for the straight
locks 124 extend straight radially inwardly toward the tandem connector body.
Once installed, the tandem connector 102 is effectively fixed in the tandem
port. If any removal force is applied to the tandem tube or connector, the
10 caroming surfaces 130 will bear against the lower rim of the tandem port,
thereby caroming the corresponding first pair of legs 120 inwardly until the
two
legs in the pair meet. Because of the angled surfaces 130, the first pair of
legs 120 are bent inwardly before the second pair of legs 120 begin to bend
inwardly through any action of the rim of the tandem port. Moreover, any
15 bending of the second pair of legs 120 will cause them to contact the other
pair
of legs, preventing any further inward bending of the legs. The camped
locks 122 are dimensioned so that the outer edges of the camped locks will
still
engage the rim of the tandem port even when the innermost points of the first
pair of legs 120 would be touching along the center line, because of bending
at
the bending points 134. Additionally, the guides for the straight locks 124
are
dimensioned so that they still engage the rim of the tandem port even when
they
are bent inwardly to contact the first pair of legs. As a result, no amount of
forrx will unlock the legs from the rim of the tandem port, without destroying
the connector itself. It should be noted that the connector can still be
inserted
into the tandem port and locked since the bending upon such insertion takes
place
at the point where the legs join the rest of the tandem connector body 108
rather
than solely at the point where the camped locks 122 and straight locks 124
join
the connector legs.
In the preferred embodiment, a tandem tube connector having an internal
radius at the legs of approximately 0.323 inches and an internal radius at the
opposite end of approximately 0.290 inches has a thickness for the legs of
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16
approximately 0.400 inches and an outside diameter at the points of the camped
locks 122 of 0.573 inches and an outside diameter at the straight locks 124 of
approximately 0.543 inches. The distance from the distal side of the rim 106
to
the proximal-most point on the camped locks 122 is preferably about 0.790,
which is the same as the distance to the proximally-facing surfaces on the
straight
locks. Tolerances should be made to ensure proper Seal between the tandem
connector body and the port while still allowing the movement of the legs to
maintain a stable lock. An alternative lock has the body extend completely to
the
end of the locking elements (filling the openings between the legs to form a
complete cylinder) and reducing the radial size of the locks while still
ensuring a
stable lock and easy installation of the connector in the port while ensuring
a
proper seal.
The tandem tube valve 136 (FIGS. 10-14) permits two way fluid flow
through the tandem tube when the tandem tube valve 136 is mounted to a patient
port on a canister, but prevents fluid flow out of the valve when the valve is
disconnected. The tandem tube valve substantially minimizes the possibility of
contamination when tandem-connected canisters are disconnected, and while any
given liner-lid combination is being disposed. The tandem valve is preferably
placed in the portion of the tandem tube which is to be connected to a
secondary
canister since the habit of most technicians is to disconnect tandem tubes
from
the secondary canisters rather than from the primary canister. However, it
should be understood that suitable valves can be placed at either end of the
tandem tube to achieve the same purpose, especially if both ends of the tandem
tube can be disconnected from their respective ports.
The tandem valve preferably includes a tandem valve housing top 138 and
a bottom 140. The housing positions and retains a flapper valve 142 and a
wiper
valve 144, having a wall 145 defining an opening for the riser portion of the
patient port, separated by a valve spacer 146. These elements will be
described
more fully below.
The housing top 138 includes one or more ribs 148 for frictionally
engaging the other end of the tandem tube 100. The ribbed portion of the
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17
housing defines a passageway 1S0 through which fluid may pass from the tandem
tube into the secondary canister. The passageway terminates in the interior
1S2
of the housing top 138. In longitudinal cross-section, the interior of the
housing
is substantially trapezoidal in shape with the narrower portion adjacent the
passageway 1S0 and the wider portion at an opening lS4 for the housing top. A -
plurality of supporting ribs 156, preferably eight, are uniformly distributed
around the inside circumference of the trapezoidal housing portion and diverge
slightly from the narrow portion of the housing to the opening 154. The
ends 158 of the supporting ribs are spaced from the adjacent wall to form
recesses 160 for receiving an outer circumferential w :11 162 on the flapper
valve 142 (FIG. 11). The spaced ends 158 engage a support surface 164 on the
flapper valve interior to the wall 162 and exterior to the moveable valve
element 166 of the flapper valve. The trapezoidal housing portion provides
sufficient space for the moveable valve element 166 to move into the housing
to
permit fluid flow past the flapper valve from the tandem tube into the
secondary
canister.
The flapper valve fits within a bore 168 in the opening 1S4 and is held in
place by the spacer 146 (FIG. 11). The wiper valve 144 fits against the
opposite
side of the spacer 146 and is sandwiched in place by the bottom portion 140 of
the tandem valve housing.
The spacer fits into a counterbore 170 in the opening 1S4 of the top
housing. The counterbore 170 is formed in an end wall 172 of the top housing
which is angled to accept the mating bottom housing portion 140. The outer
circumferential wall 174 of the bottom housing portion 140 engages a circular
channel 176 formed outside of the end wall 172 so that the top and bottom
housing portions may be welded or otherwise bonded and sealed.
The flapper valve 142 is preferably substantially symmetrical about a
plane intersecting the central axis of the flapper valve thereby forming a
plane to
which the central axis is normal. The wall portion 162 is part of a short
cylindrical outer wall 178 surrounding a ring portion 180. The supporting
surface 164 on one side of the ring portion engages the ends 158 on the
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18
blades 156. On the opposite side, surface 182 and surface 184 engage mating
portions 186 of the spacer 146. Flapper valve 142 is thereby sandwiched
between the spacer 146 and the top housing 138.
The moveable valve element 166 is coupled to and supported by the ring
portion 180 by a primary web 190.
Spacer 146 (FIG. 10) is also preferably symmetrical about a plane to
which the center axis of the spacer is normal. The spacer preferably has a
wall 194 defining an opening 196 through which the cone or riser of the
patient
port of the secondary canister is inserted to engage and open the valve
element of
the flapper valve in the valve housing. On the flapper valve side of the
spacer,
an inner groove 200 as well as the wall 194 define the valve seat 202 against
which the valve element 166 seats when the tandem tube valve is removed from
the mating port.
On the wiper valve side of the spacer, the spacer again has a first outer
groove 204 for engaging a corresponding circular ridge 206 in the inside of
the
bottom housing 140. The inward adjacent circular ridge 208 on the spacer
engages the groove 210 to sandwich the wiper valve 144 between circular
ridge 212 on the spacer and circular ridge 214 on the bottom housing.
Preferably, the groove 210 and the corresponding ridge 208 capture part of the
wiper valve to hold it in place.
FIGS. 12-14 demonstrate the operation of the tandem valve. In FIG. 12,
the tandem valve is fully seated on its corresponding patient port so that the
riser
of the patient port holds the moveable valve element of the flapper valve open
permitting fluid flow from the tandem tube into the canister in accordance
with
the proper pressure differential. Additionally, the opening 145 in the wiper
valve 144 elastically surrounds the riser. In FIG. 13, the tandem valve is
partially removed from its corresponding riser and the moveable valve element
of
the flapper valve follows the top of the riser as the riser is removed from
the
tandem valve housing. The opening in the wiper valve 144 slides along the
riser
as the riser is removed wiping any fluid in front of it. Finally, in FIG. 14,
the
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19
moveable valve element of the flapper valve is seated on the valve seat 202
and
the wiper valve is almost completely removed from the riser.
With the tandem valve, further flow of fluid from the tandem tube
outward of the tandem valve is prevented once the tandem tube is disconnected
from its associated tandem port. Any fluid within the tube is retained therein
or
falls back into its primary canister. The valve operates regardless of whether
or
not removal of the tandem tube valve is intentional or accidental.
A tandem tube valve cap 216 (not shown) is retained on the tandem tube
so that the opening on the tandem tube valve housing can be capped at any
time.
After being capped, the tandem tube is fully sealed between the cap and the
liner
of the lid-liner combination to which the tandem tube is connected.
In the preferred embodiment, the canister lid, connectors and ports are
formed from high density polyethylene. The liner is preferably formed from low
density polyethylene and the tandem tube connector is preferably formed from a
polypropylene homopolymer. The port caps such as the tandem tube valve cap
are preferably formed from low density polyethylene. The valve housing is
preferably formed from styrene, as is the tandem valve spacer, while the
flapper
valve is preferably formed from natural or synthetic polyisoprene and the
wiper
valve is preferably formed from natural pure gum rubber. The opening 145 in
the wiper valve 144 is preferably 0.125 inch for a minimum outside patient
port
diameter of 0.361 inch.
A vacuum canister fluid collection system and its components have been
described and which will minimize the possibility of reflux or loss of fluid
upon
removal of vacuum, thereby minimizing the possibility of contamination or
injury. Additionally, the possibility of contamination through accidental
removal
of caps on ports or loss of vacuum is also minimized. The system is designed
so
that full canisters will have their lids unsealed and disengaged from the
canister
upon removal of vacuum to minimize any possible pressure differential between
the liner and atmospheric pressure. Preexisting pressure differentials and
components are beneficially used to accomplish this result.
CA 02443243 2003-10-08
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Although the present invention has been described in detail with reference-
only to the presently preferred embodiments, it will be appreciated by those
of
ordinary skill in the art that various modifications can be made without
departing
from the spirit of the invention. Accordingly, the invention is limited only
by
5 the following claims.
