U.S. patent application number 17/453084 was filed with the patent office on 2022-02-17 for expandable fluid collection canister.
The applicant listed for this patent is KCI Licensing. Invention is credited to Christopher Brian LOCKE, Gareth STEPHENSON.
Application Number | 20220047797 17/453084 |
Document ID | / |
Family ID | 1000005940564 |
Filed Date | 2022-02-17 |
United States Patent
Application |
20220047797 |
Kind Code |
A1 |
LOCKE; Christopher Brian ;
et al. |
February 17, 2022 |
EXPANDABLE FLUID COLLECTION CANISTER
Abstract
A bodily fluid collection system includes a reduced pressure
treatment unit for providing reduced pressure to a fluid collection
system through a canister having a container with an inlet adapted
to be fluidly coupled to the fluid collection system, an outlet
adapted to be connected to a source of reduced pressure, and an
absorptive lamination disposed within the container. The absorptive
lamination may be formed from a plurality of absorptive layers and
wicking layers interleaved between the absorptive layers that
collectively manifold bodily fluids from a tissue site into and
throughout the absorptive lamination to trap and collect the bodily
fluids. The container expands as the absorptive lamination swells
with the bodily fluid being collected.
Inventors: |
LOCKE; Christopher Brian;
(Bournemouth, GB) ; STEPHENSON; Gareth;
(Southampton, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KCI Licensing |
San Antonio |
TX |
US |
|
|
Family ID: |
1000005940564 |
Appl. No.: |
17/453084 |
Filed: |
November 1, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16107835 |
Aug 21, 2018 |
11191887 |
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17453084 |
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14162432 |
Jan 23, 2014 |
10092682 |
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16107835 |
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61780143 |
Mar 13, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 1/90 20210501; A61F
13/0216 20130101; A61F 13/0223 20130101; A61M 1/0001 20130101; A61M
1/88 20210501; A61M 1/602 20210501 |
International
Class: |
A61M 1/00 20060101
A61M001/00; A61F 13/02 20060101 A61F013/02 |
Claims
1. A canister for collecting bodily fluids from a tissue site,
comprising: a first wall, a second wall, the first wall and the
second wall substantially impervious to vapor, a plurality of
absorptive layers, a plurality of wicking layers positioned
proximate the plurality of absorptive layers, a connecting member
positioned about a perimeter of the first wall and the second wall
and configured to couple the first wall and the second wall, and
one or more vapor permeable regions disposed in the first wall and
the second wall.
2. The canister of claim 1, further comprising: an inlet configured
to be in fluid communication with the tissue site; an outlet
configured to be in fluid communication with a reduced pressure
source; and a container including the first wall and the second
wall, the container configured to collect fluids from the tissue
site.
3. The canister of claim 2, wherein the first wall, the second
wall, and the connecting member define a chamber.
4. The canister of claim 3, wherein the inlet and the outlet are
disposed on one of the first wall or the second wall, and wherein
the canister further comprises a tube fluidly coupled to the inlet
and extending into the chamber away from the outlet.
5. The canister of claim 1, wherein the first wall and the second
wall are oriented parallel to the absorptive layers and the wicking
layers.
6. The canister of claim 1, wherein the wicking layers have flow
channels for supporting fluid flow across a surface of the
absorptive layers.
7. The canister of claim 1, further comprising at least one spacer
between the wicking layers of the absorptive layers to maintain a
space between adjacent wicking layers under reduced pressure.
8. The canister of claim 1, wherein the first wall and the second
wall are configured to expand as the absorptive layers swell.
9. The canister of claim 1, wherein the one or more vapor permeable
regions comprise a polygonal shape.
10. The canister of claim 1, wherein the one or more vapor
permeable regions comprise an elliptical shape.
11. The canister of claim 1, wherein the one or more vapor
permeable regions comprise between about 5% and about 95% of a
surface area of the first wall and the second wall.
12. The canister of claim 11, wherein the one or more vapor
permeable regions have a cross-sectional thickness less than about
50 .mu.m and greater than about 5 82 m.
13. The canister of claim 1, wherein the first wall and the second
wall comprise a thermoplastic material having a cross-sectional
thickness greater than about 50 82 m.
14. The canister of claim 1, wherein the canister further comprises
a first textured layer disposed adjacent the first wall.
15. The canister of claim 1, wherein the canister further comprises
a second textured layer disposed adjacent the second wall.
16. The canister of claim 1, wherein the connecting member
comprises pleats.
17. The canister of claim 1, wherein the connecting member
comprises an elastic material.
18. The canister of claim 1, further comprising an antimicrobial
agent disposed in at least one of the plurality of absorptive
layers and the plurality of wicking layers.
19. The canister of claim 1, wherein the first wall is adapted to
translate away from the second wall.
Description
[0001] The present application is a Continuation of U.S. patent
application Ser. No. 16/107,835, entitled "EXPANDABLE FLUID
COLLECTION CANISTER," filed Aug. 21, 2018, which is a Divisional of
U.S. patent application Ser. No. 14/162,432, entitled "EXPANDABLE
FLUID COLLECTION CANISTER," filed Jan. 23, 2014, now U.S. Pat. No.
10,092,682, which claims the benefit, under 35 USC .sctn. 119(e),
of U.S. Provisional Patent Application No. 61/780,143, entitled
"EXPANDABLE FLUID COLLECTION CANISTER," filed Mar. 13, 2013, which
are incorporated herein by reference for all purposes.
TECHNICAL FIELD
[0002] The present invention relates generally to tissue treatment
systems and in particular to systems and methods for collecting
bodily fluid.
BACKGROUND
[0003] Clinical studies and practice have shown that providing a
reduced pressure in proximity to a tissue site augments and
accelerates the growth of new tissue at the tissue site. The
applications of this phenomenon are numerous, but application of
reduced pressure has been particularly successful in treating
wounds. This treatment (frequently referred to in the medical
community as "negative pressure wound therapy," "reduced pressure
therapy," or "vacuum therapy") provides a number of benefits,
including faster healing and increased formulation of granulation
tissue. Typically, reduced pressure is applied to tissue through a
porous pad or other manifold device. The porous pad contains cells
or pores that are capable of distributing reduced pressure to the
tissue and channeling fluids that are drawn from the tissue. The
porous pad often is incorporated into a dressing having other
components that facilitate treatment.
[0004] Wound fluids or exudates are generally collected in a
canister for disposal or analysis. Wound fluid primarily comprises
plasma in addition to red and white blood cells, platelets,
bacteria, and a variety of proteinaceous material. Plasma consists
primarily of saline. In clinical practice, canisters should be
sized appropriately to obviate the need for frequent replacement
even when used in the treatment of patients with wounds generating
a high volume of exudate. Conversely, canisters should not be bulky
so as to fill care facilities' storage spaces or consume
unnecessary resources for hazardous waste disposal of canisters
filled with potentially infectious bodily fluid.
SUMMARY
[0005] In one illustrative embodiment, a bodily fluid canister
comprises an inlet, an outlet, a container, and a plurality of
layers of absorptive material and a plurality of layers of wicking
material contained within the container. The plurality of layers of
wicking material may be situated proximate to the plurality of
layers of absorptive material. The plurality of layers of wicking
material may be oriented in an alternating pattern with the
plurality of layers of absorptive material such that each layer of
absorptive material is proximate to at least one layer of manifold
material. The plurality of layers of wicking material and the
plurality of layers of absorptive material may be oriented
essentially vertically with the container.
[0006] In another illustrative embodiment, a bodily fluid canister
is provided for use with a reduced pressure treatment system. The
bodily fluid canister comprises an inlet, an outlet, liquid
impervious container, and a plurality of layers of absorptive
material and a plurality of layers of wicking material contained
within the container. The inlet may be disposed in the container,
the inlet adapted to be fluidly connected to a tissue site. The
reduced pressure treatment system may include a porous pad
positioned proximate to a tissue site. An outlet may be disposed in
the container and is adapted to be fluidly connected to a reduced
pressure source. A plurality of layers of wicking material and a
plurality of layers of absorptive material may be positioned within
the container. The plurality of layers of wicking material and the
plurality of layers of absorptive material may be positioned
proximate to one another and each of the plurality of layers of
absorptive material may be positioned proximate to at least one of
the plurality of layers of manifold material. The plurality of
layer of wicking material and the plurality of layers of absorptive
material may be oriented essentially vertically within the
container. The container may be configured to be volumetrically
expandable.
[0007] In still another embodiment, a method for volumetrically
expanding a bodily fluid canister is provided. The method comprises
introducing bodily fluid into a canister, the canister comprising a
container containing a plurality of layers of absorptive material
within the canister adapted to attract and retain bodily fluid and
a plurality of layers of wicking material within the canister
adapted to distribute bodily fluid along the plurality of layers of
absorptive material. The method further comprises volumetrically
expanding the canister, the canister configured to expand upon
bodily fluid distribution to the plurality of layers of wicking
material and the plurality of layers of absorptive material.
[0008] In yet another embodiment, a canister for collecting bodily
fluids from a fluid collection system for delivering reduced
pressure to a tissue site from a source of reduced pressure is
disclosed. The canister may comprise a container having a chamber
being expandable to receive and collect bodily fluids from the
tissue site in response to the application of the reduced pressure,
an inlet fluidly coupled to the chamber of the container and
configured to be in fluid communication with the fluid collection
system for delivering the bodily fluids into the chamber of the
container, and an outlet fluidly coupled to the chamber of the
container and configured to be in fluid communication with the
source of reduced pressure for providing reduced pressure through
the chamber of the container to the fluid collection system. The
canister may further comprise an absorptive lamination disposed
within the container and adapted to trap and collect a liquid
portion of the bodily fluids separated from the gaseous portion of
the bodily fluids flowing from the inlet to the outlet within the
container, wherein the container expands as the absorptive
lamination swells to absorb the liquid portion of the bodily
fluids. The absorptive lamination may comprise a plurality of
absorptive layers and a plurality of wicking layers interleaved
between the absorptive layers.
[0009] Other objects, features, and advantages of the illustrative
embodiments will become apparent with reference to the drawings and
detailed description that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 shows a perspective view of a bodily fluid collection
system comprising a reduced pressure treatment unit for providing
reduced pressure to a fluid collection system through a first
embodiment of a canister including a container having absorptive
layers with interleaving wicking layers disposed in the container
according to an illustrative embodiment;
[0011] FIG. 2 shows an exploded, cross-sectional view of the
canister and a partially schematic cross-sectional view of the
reduced pressure treatment unit comprising components of the bodily
fluid collection system of FIG. 1;
[0012] FIG. 2A shows the canister of FIG. 2 with the container
partially filled with bodily fluids drawn from the fluid collection
system;
[0013] FIG. 2B shows the canister of FIG. 2 with the container
completely filled with bodily fluids drawn from the fluid
collection system; and
[0014] FIG. 3 shows a perspective view of a second embodiment of a
container for collecting bodily fluids in the bodily fluid
collection system of FIG. 1.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0015] In the following detailed description of several
illustrative embodiments, reference is made to the accompanying
drawings that form a part hereof, and in which is shown by way of
illustration specific preferred embodiments in which the invention
may be practiced. These embodiments are described in sufficient
detail to enable those skilled in the art to practice the
invention, and it is understood that other embodiments may be
utilized and that logical structural, mechanical, electrical, and
chemical changes may be made without departing from the spirit or
scope of the invention. To avoid detail not necessary to enable
those skilled in the art to practice the embodiments described
herein, the description may omit certain information known to those
skilled in the art. The following detailed description is,
therefore, not to be taken in a limiting sense, and the scope of
the illustrative embodiments are defined only by the appended
claims.
[0016] The term "reduced pressure" as used herein generally refers
to a pressure less than the ambient pressure at a tissue site that
is being subjected to treatment. In most cases, this reduced
pressure will be less than the atmospheric pressure at which the
patient is located. Alternatively, the reduced pressure may be less
than a hydrostatic pressure associated with tissue at the tissue
site. Although the terms "vacuum" and "negative pressure" may be
used to describe the pressure applied to the tissue site, the
actual pressure reduction applied to the tissue site may be
significantly less than the pressure reduction normally associated
with a complete vacuum. Reduced pressure may initially generate
fluid flow in the area of the tissue site. As the hydrostatic
pressure around the tissue site approaches the desired reduced
pressure, the flow may subside, and the reduced pressure is then
maintained. Unless otherwise indicated, values of pressure stated
herein are gauge pressures. Similarly, references to increases in
reduced pressure typically refer to a decrease in absolute
pressure, while decreases in reduced pressure typically refer to an
increase in absolute pressure.
[0017] The term "tissue site" as used herein refers to a wound or
defect located on or within any tissue, including but not limited
to, bone tissue, adipose tissue, muscle tissue, neural tissue,
dermal tissue, vascular tissue, connective tissue, cartilage,
tendons, or ligaments. The term "tissue site" may further refer to
areas of any tissue that are not necessarily wounded or defective,
but are instead areas in which it is desired to add or promote the
growth of additional tissue. For example, reduced pressure tissue
treatment may be used in certain tissue areas to grow additional
tissue that may be harvested and transplanted to another tissue
location.
[0018] Referring to FIGS. 1 and 2, a reduced pressure treatment
system 10 comprises a fluid collection system 100 for applying
reduced pressure therapy to a patient, a reduced pressure treatment
unit 101 for providing the reduced pressure, and a canister 102
fluidly coupled between the fluid collection system 100 and the
reduced pressure treatment unit 101 for collecting fluids from a
patient according to one illustrative embodiment. The canister 102
comprises a container 103 having a chamber, an inlet 104 being a
coupling for providing fluid communication into the chamber of the
container 103, and an outlet 105 being a coupling for providing
fluid communication out from the chamber of the container 103. The
inlet 104 is adapted to be fluidly coupled to the fluid collection
system 100 for providing reduced pressure to the fluid collection
system 100 and receiving bodily fluids from the patient. The outlet
105 is adapted to be connected to a reduced pressure port 107 of
the reduced pressure treatment unit 101 to provide reduced pressure
to the fluid collection system 100 from a reduced pressure source
108 that may be contained within the reduced pressure treatment
unit 101. The inlet 104 and the outlet 105 are preferably disposed
at one end of the container 103 so that both may be positioned at a
higher elevation relative to the other end of the container 103
when the canister 102 is utilized in operation. The canister 102
may further comprise a support member such as, for example, a
carrier ring 109 that may be releasably connected to the reduced
pressure treatment unit 101 to hold the container 103 in place
during operation of the reduced pressure treatment unit 101.
[0019] The fluid collection system 100 is adapted to be positioned
proximate a tissue site 110 of a patient for delivering reduced
pressure to the tissue site 110 and collecting bodily fluids from
the tissue site 110. The fluid collection system 100 comprises a
manifold 112 in fluid communication with the tissue site 110 and a
drape 114 adapted to cover the manifold 112 for providing a
substantially airtight seal over the tissue site 110. The fluid
collection system 100 may further comprise a connector 116 fluidly
coupled to the manifold 112 through the drape 114 and a conduit or
tube 118 containing at least one lumen for the transmission of
fluids, both gaseous and liquid. The tube 118 is adapted to be
fluidly coupled between the connector 116 and the inlet 104 of the
canister 102 for transmitting fluids between the canister 102 and
the tissue site 110.
[0020] The manifold 112 may be a bioabsorbable or bioinert material
capable of distributing reduced pressure at various desired levels.
The drape 114 may include an adhesive seal (not shown) that not
only maintains the reduced pressure at various levels, but also
holds the fluid collection system 100 in place over the tissue site
110. The manifold 112 may be a bioabsorbable or bioinert material
capable of distributing reduced pressure to the tissue site 110. In
one embodiment, the manifold 112 may be an open cell, reticulated
foam comprising, for example, a polyurethane material. The wound
dressing 112 delivers reduced pressure to the tissue site 110 to
provide therapeutic treatment to the tissue site 110 and allows
exudates and bodily fluids to flow from the tissue site 110 to the
canister 102 where the exudates and bodily fluids are
collected.
[0021] The reduced pressure treatment unit 101 may comprise the
reduced pressure source 108 as described above. The reduced
pressure source 108 may be, for example, a vacuum pump driven by a
motor. In another embodiment, reduced pressure may be provided by a
manually-actuated pump such as a compressible bellows pump. In
still another embodiment, the reduced pressure may be provided by a
wall suction port either with or without a separate pressure
regulator. The reduced pressure treatment unit 101 may also
comprise a processing unit (not shown) for controlling various
features of the reduced pressure treatment unit 101 such as, for
example, the level and timing of the reduced pressure being applied
to the tissue site 110. The reduced pressure treatment unit 101 may
further comprise other equipment such as, for example, a source of
positive pressure.
[0022] The container 103 may be constructed of a liquid impervious
material such as, for example, a thermoplastic material such as
polyurethane to contain the exudates and bodily fluids collected
from the tissue site 110. The chamber of the container 103 may have
a volume that is preferably variable to accommodate the collection
of exudates and bodily fluids from the tissue site 110 expanding
from an empty state to a full state after collecting such fluids.
In one embodiment, the container 103 may comprise a flexible bag
having walls that are elastic and expandable as needed to
accommodate the collection of exudates and bodily fluids. In
another embodiment, the flexible bag may have walls that are less
elastic or inelastic but nonetheless collapsible in the empty state
and expandable to the full state as needed to accommodate the
collection of exudates and bodily fluids. In one embodiment, the
container 103 may comprise a flexible bag formed from a single
tubular sheet of film sealed at both ends. In another embodiment,
the container 103 may comprise a flexible bag formed from two
sheets of film sealed around the edges and shown more specifically
in FIG. 1 which shows the chamber having an oval shape. The chamber
of the container 103 may have a circular or rectangular shape
(e.g., see the chamber of container 303 in FIG. 3) as necessary to
accommodate the structure and fluidics of the system.
[0023] In yet another embodiment, the container 103 may comprise
two walls joined around the edges by a connecting member that
provides expandability of the chamber of the container 103.
Referring more specifically to FIG. 2, the container 103 may
comprise a first wall 120, a second wall 122, and a connecting
member 124, wherein the perimeters of the first wall 120 and the
second wall 122 are joined together by the connecting member 124.
The first wall 120, the second wall 122, and the connecting member
124 define the chamber of the container 103 that may accommodate
the exudates and bodily fluids as they are collected from the
tissue site 110. In one embodiment, the connecting member 124 may
comprise one or more pleats 126 that allow the chamber of the
container 103 to expand from the empty state to the filled state.
In another embodiment, the connecting member 124 may comprise a
material with elastic characteristics. In yet another embodiment,
the connecting member 124 may be configured as a Z-fold to permit
expansion of the chamber of the container 103. Other configurations
of the container 103 may provide similar volumetric expandability
of the chamber.
[0024] As indicated above, the inlet 104 and the outlet 105 are
preferably disposed at one end of the container 103 so that both
may be positioned at a higher elevation relative to the other end
of the container 103 when the canister 102 is utilized in
operation. Thus, the container 103 may be oriented more vertically
with the inlet 104 and the outlet 105 being elevated to utilize
gravity to facilitate filling the chamber of the container 103 with
the exudates and bodily fluids being collected. In one embodiment,
the container 103 may contain an absorptive material such as a
foam, hydrogel, or a water-swelling polymer for collecting and
treating the exudates and bodily fluids being collected from the
tissue site 110. In such embodiments, it is also desirable that the
exudates and bodily fluids enter the chamber of the container 103
on the distal side of the container 103 adjacent the first wall 120
allowing the absorptive material to trap and collect the liquid
fluids while the gaseous fluids exit the chamber of the container
103 on the proximal side of the container 103 adjacent the second
wall 122. Thus, the inlet 104 and the outlet 105 may be disposed on
opposing walls of the container 103. In another embodiment as more
specifically shown in the figures, the inlet 104 and the outlet 105
may both be disposed on the proximal side of the container 103
through the second wall 122 wherein the inlet 104 is in fluid
communication with a tube 127 having a distal end 128 extending
within the chamber to the distal side of the container 103 adjacent
the first wall 120 so that the absorptive material better traps and
collects the liquid fluids while the gaseous fluids exit the
chamber of the container 103 through the outlet 105 as illustrated
by arrows 129 representing the flow of the fluids.
[0025] When the container 103 is filled with an absorptive material
in bulk volume, the absorbent material often failed to expand or
inflate the container 103 to completely fill the chamber of the
container 103 with the exudates and bodily fluids being collected
from the tissue site 110. Moreover, the absorptive material tended
to saturate in localized areas without absorbing the fluids
throughout the entire volume of the absorptive material. Even when
the container 103 and the absorptive material within the container
103 were oriented vertically, the vertical orientation exacerbated
the localized saturation condition. It is desirable to overcome
these problems so that the container 103 would be completely filled
to reduce the expense associated with utilizing additional
containers and reduce the maintenance required by the patient or a
caregiver.
[0026] These problems are overcome by disposing individual layers
of absorptive material within the container 103 wherein the
absorptive layers are spaced apart from one another that may form
an absorptive lamination to enhance the collection and flow of
fluids throughout the entire volume of the absorptive lamination.
These problems are further overcome by interleaving layers of
wicking material within the space between the absorptive layers to
further enhance the flow of fluids between the absorptive layers
and throughout the entire volume of the absorptive lamination.
Using such an absorptive lamination including wicking layers
interleaved between the absorptive layers within the container 103
greatly enhances the ability of the container 103 to expand and
completely fill to overcome these problems and do so regardless of
orientation. When the container 103 contains an absorptive
lamination as just described, the absorptive capabilities of the
container 103 are still enhanced when the container is oriented in
a horizontal position as opposed to a vertical position.
[0027] Referring more specifically to FIG. 2, one exemplary
embodiment of an absorptive lamination 130 is shown and comprises a
plurality of absorptive layers 132 of absorptive material that are
spaced apart from each other as described above. The absorptive
layers 132 may be spaced apart from each other by spacers (not
shown) or any other means to maintain the spaced apart relationship
between the absorptive layers 132 when subjected to a reduced
pressure during operation of the reduced pressure treatment unit
101. The absorptive lamination 130 contains a plurality of wicking
layers 134 of wicking material disposed between the absorptive
layers 132. In one embodiment, one wicking layer 134 may be
disposed or interleaved between each absorptive layer 132 as
described above but not shown. In another embodiment, one wicking
layer 134 may be disposed proximate each side of one of the
absorptive layers 132 such that a pair of wicking layers 134 may be
associated with each absorptive layer 132 as shown. In this
embodiment, the absorptive lamination 130 may further comprise
spacers 135 disposed between each pair of wicking layers 134 to
provide further spacing between the absorptive layers 132. The
absorptive lamination 130 may be oriented within the chamber of the
container 103 so that the absorptive layers 132 and the wicking
layers 134 are substantially parallel to the first wall 120 and the
second wall 122 of the container 103. These embodiments enhance the
distribution of bodily fluids to the absorptive layers 132
throughout the entire chamber of the container 103 to enhance the
fluid storage capability of the absorptive lamination 130.
[0028] The wicking layers 134 may comprise a wicking material
having flow channels that support the flow of fluids at least
through the width of each wicking layer 134, i.e., generally
perpendicular to the length or longitudinal axis of the wicking
layer 134. The flow channels of the wicking material are capable of
supporting the flow of fluids even when under reduced pressure
being applied within the container 103. The wicking material may be
a non-woven material such as, for example, Libeltex TDL2 available
from LIBELTEX bvba located in Belgium, or a reticulated open-cell
polyurethane foam. The absorptive layers 132 may comprise, for
example, a textile substrate (e.g., woven or knit fabrics), a foam,
a hydrogel, a hydrocolloid, a superabsorbent polymer (e.g., Texsus
CCBSL 130LL available from Texsus Spa located in Italy), a silica
gel, a water swelling polymer, a polysaccharide (e.g., chitosan,
carboxymethylcellulose, hydroxylmethylcellulose, hyaluronic acid,
alginate, pectin, etc.), a proteinaceous material (glycoprotein,
gelatin, etc.), and combinations thereof.
[0029] The wicking layers 134 and the absorptive layers 132 of may
each further comprise an antimicrobial agent and thus be adapted to
have antimicrobial properties to effect a bioburden log reduction
of greater than one or, more preferably, greater than three. By way
of a non-limiting example, this antimicrobial property may be
accomplished by adding ionic silver to the wicking material of the
wicking layers 134 or the absorptive material of the absorptive
layers 132. The wicking layers 134 and the absorptive layers 132 of
may each further comprise other chemicals or agents to facilitate
the collection and storage of exudates and bodily fluids from the
tissue site 110.
[0030] The canister 102 may further comprise a first textured layer
136 contained within the container 103 adjacent to the first wall
120 and a second textured layer 137 contained within the container
103 adjacent to the second wall 122. The first textured layer 136
and the second textured layer 137 may be constructed from a fluid
impermeable material. The first textured layer 136 and the second
textured layer 137 may each be a sheet of material having a
textured side that is corrugated or comprises a plurality of
protrusions or projections extending into the chamber of the
container 103 and facing the absorptive lamination 130. The
textured sides of the first textured layer 136 and the second
textured layer 137 may have other shapes resulting from being
channeled, creased, folded, grooved, indented, pleated, or ribbed.
When the chamber of the container 103 subjected to a reduced
pressure, the first textured layer 136 and the second textured
layer 137 collapse against the sides of the absorptive lamination
130. The first textured layer 136 and the second textured layer 137
may provide a fluid reservoir for a bolus of bodily fluid entering
the container 103, allowing the bodily fluid from the tissue site
110 to be distributed more thoroughly across the face of the
absorptive lamination 130 to enhance the ability of the absorptive
layers 132 collect and store such fluids. Additionally, textured
surfaces of the first textured layer 136 and the second textured
layer 137 provide additional spacing adjacent the outermost
absorptive layers 132 and/or the wicking layers 134 to further
enhance the flow of bodily fluids throughout the entire absorptive
lamination 130.
[0031] The absorptive layers 132 and the wicking layers 134 may be
organized in other alternating sequences of absorptive material and
wicking material. Additionally, the absorptive layers 132 and the
wicking layers 134 may be formed into a composite rather than being
discrete layers of material. For example, an absorptive composite
may be formed from co-extruding absorptive material and wicking
material such that the absorptive composite possesses
characteristics similar to the characteristics of the discrete
absorptive layers 132 and the wicking layers 134. The absorptive
and wicking lamina of the absorptive composite would then be
aligned in an alternating sequence when disposed within the
container 103.
[0032] In operation, the absorptive lamination 130 including
wicking layers interleaved between the absorptive layers within the
container 103 greatly enhances the ability of the container 103 to
expand and completely fill the chamber as described above,
especially when oriented in a generally vertical position.
Referring more specifically to FIGS. 2, 2A, and 2B, the container
102 of the canister 102 is shown as being substantially vertically
oriented and expanding from an empty state to being partially
filled and then completely filled, respectively. Referring to FIG.
2A, the container 102 is shown as being partially filled with
bodily fluids and expanding at the lower end near the bottom of the
container 102. The bodily fluids and exudates are drawn from the
tissue site 110 into the inlet 104 and the tube 127, and then flow
into the chamber of the container 102 through the distal end 128 of
the tube 127. When the bodily fluids enter the chamber of the
container 102, they begin to separate into gaseous and liquid
components with the gaseous fluids exiting the outlet 105 as
indicated by the arrows 129 and the liquid fluids manifolding down
the side of the absorptive lamination 130 with the assistance of
gravity as indicated by liquid line 139. The liquid bodily fluids
are manifolded through a combination of the wicking action created
by the wicking layers 134 and the osmotic pressure of the
absorptive layers 132, and supplemented by the effects of gravity
which pulls the fluid downward toward the bottom of the container
102 which begins to expand along with the expanding absorptive
layers 132. This leaves the top of the container 102 generally
unobstructed by the liquid fluids to manifold the reduced pressure
through the tube 127 to the outlet 105. This action also
facilitates fluid flow by pulling intermittent bolus' of liquid
fluids and exudates from the tissue site 110 down to the bottom of
the container 102 by gravity where the absorbent layers 132 have
more time to trap and retain the liquid fluids.
[0033] As can be seen in the illustration, the absorptive layers
132 continue to expand as the wicking layers 132 continue to
channel the liquid fluids across the surfaces of the absorptive
layers 132 and the longer the absorptive layers 132 are submersed
in the liquid fluids. For example, the most distal absorptive layer
132a has expanded more at the lower end which has expanded more
than the lower end of the most proximal absorptive layer 132b with
varying degrees of absorption and expansion for each intervening
absorptive layer 132. As the container 102 continues to fill with
the liquid fluids, the absorptive layers 132 continue to expand
until they reach a full capacity such that the container 102 is
fully expanded in a filled state as shown in FIG. 2B. When the
chamber of the container 102 is substantially filled, the liquid
fluid eventually covers the distal end 128 of the tube 127 as shown
by fluid line 139' which substantially prevents the continuing flow
of bodily fluids from the tissue site 110. The container 102 is
capable of expanding with the expansion of the absorptive
lamination 132 by means of any of the embodiments described above.
It should be understood that the container 102 will function in a
substantially horizontal position by virtue of the wicking action
provided by the wicking layers 134 without the aid of gravity as
long as the distal end 128 of the tube 127 is in an elevated
position.
[0034] Referring now to FIG. 3, a container 303 is shown is
substantially similar in all respects to the container 103 of FIGS.
1 and 2 except for the shape as pointed out above. The container
303 also comprises a first wall 320 and a second wall 322 joined
together by the connecting member 324. As also described above, the
container 303 may be constructed of a liquid impervious material
such as, for example, a thermoplastic such as polyurethane. In one
exemplary embodiment, the first wall 320 and the second wall 322 of
the container 303 may be constructed of polyurethane film having a
cross-sectional thickness greater than about 50 .mu.m wherein the
container 303 is substantially impervious to vapor. In another
exemplary embodiment, the first wall 320 and a second wall 322 of
the container 303 may comprise a material permeable to vapor such
as, for example, the same polyurethane film wherein the
polyurethane film has a cross-sectional thickness less than about
50 .mu.m but greater than about 15 82 m. If the container 303 is
permeable to vapor, the reduced pressure treatment unit 101 may
further comprise a positive pressure source 140 that may provide
positive pressure to the container 303 to facilitate the
evaporation of collected bodily fluid into vapor and the subsequent
transmission of vapor through the container 303 and into the
atmosphere. In one embodiment, the source of positive pressure 140
may be the exhaust of the source negative pressure 108. In another
embodiment, the positive pressure source 140 may be activated when
the negative pressure source 108 is deactivated.
[0035] In yet another exemplary embodiment, the first wall 320 and
the second wall 322 of the container 303 may be substantially
impervious to vapor but may further comprise portions or regions
150 having a cross-sectional thickness greater than about 5 .mu.m
and less than about 50 .mu.m that are permeable to vapor. The
regions 150 of vapor permeability allow bodily fluid collected in
the container 303 to evaporate into the atmosphere as described
above and further assisted by providing positive pressure to the
chamber of the container 303. The regions 150 may have varying
shapes such as, for example, the shape of a regular polygon or an
ellipse. The regions 150 may comprise between about 5% and about
95% of the surface area of the container 303.
[0036] In yet another embodiment, a method for collecting bodily
fluid from a tissue site is provided. The method comprises
disposing a plurality of absorptive layers with wicking layers
interleaved between the absorptive layers into a container of a
bodily fluid canister, fluidly coupling the container to both a
source of bodily fluid and a source of negative pressure, and
applying negative pressure through the container to the source of
bodily fluid. The method further comprises utilizing the negative
pressure to draw the bodily fluids from the tissue site and
manifold the bodily fluids to the absorptive layers to collect and
trap the liquid portion of the bodily fluids, and allowing the
container to volumetrically expand as the absorptive layers swell
in size, whereby the container expands to a full state after the
absorptive layers are fully absorbed with the liquid fluids.
[0037] It will be appreciated that the illustrative embodiments
described herein may be used with reduced pressure treatment
systems of any type, shape, or size and similarly with canisters of
any type, shape, or size. The location of the inlet, outlet,
semi-permeable membrane, and flexible bag may also vary depending
upon the particular collection system design. Similarly, the
geometry of the semi-permeable membrane may be modified as
necessary to conform to the contours or configuration of the
canister. Similarly, the location of the means to withdraw the
collected absorbent may also vary depending upon the particular
collection system design.
[0038] It should be apparent from the foregoing that an invention
having significant advantages has been provided. While the
invention is shown in only a few of its forms, it is not just
limited but is susceptible to various changes and modifications
without departing from the spirit thereof.
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