U.S. patent application number 17/466745 was filed with the patent office on 2021-12-23 for fluid container with pressure regulation.
The applicant listed for this patent is KCI Licensing, Inc.. Invention is credited to Richard Daniel John COULTHARD, Christopher Brian LOCKE, Benjamin Andrew PRATT.
Application Number | 20210393868 17/466745 |
Document ID | / |
Family ID | 1000005822593 |
Filed Date | 2021-12-23 |
United States Patent
Application |
20210393868 |
Kind Code |
A1 |
LOCKE; Christopher Brian ;
et al. |
December 23, 2021 |
FLUID CONTAINER WITH PRESSURE REGULATION
Abstract
A system or apparatus may include a container configured to
collect fluid from a tissue site and regulate negative-pressure
from a negative-pressure source. In some embodiments, the container
may include a regulator that receives negative pressure directly
from an unregulated negative-pressure source, such as a
wall-suction outlet. The regulator may regulate down the pressure
delivered to a collection chamber in the container, which may in
turn be connected to a tissue site.
Inventors: |
LOCKE; Christopher Brian;
(Bournemouth, GB) ; PRATT; Benjamin Andrew;
(Poole, GB) ; COULTHARD; Richard Daniel John;
(Verwood, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KCI Licensing, Inc. |
San Antonio |
TX |
US |
|
|
Family ID: |
1000005822593 |
Appl. No.: |
17/466745 |
Filed: |
September 3, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16073226 |
Jul 26, 2018 |
11141513 |
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PCT/US2017/014832 |
Jan 25, 2017 |
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17466745 |
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62288142 |
Jan 28, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 2205/3331 20130101;
A61M 1/82 20210501; A61M 1/604 20210501; A61M 1/90 20210501; A61M
1/60 20210501; A61M 2205/16 20130101; A61M 1/743 20210501 |
International
Class: |
A61M 1/00 20060101
A61M001/00 |
Claims
1. An apparatus for enclosing a fluid canister, the apparatus
comprising: a rim configured to sealingly engage the fluid
canister; a regulator comprising a regulator chamber, a first
passage fluidly coupled to the regulator chamber, a second passage
fluidly coupled to the regulator chamber, and a regulator valve
configured to regulate fluid flow through the first passage based
on changes to negative pressure in the regulator chamber; a
downstream connector fluidly coupled to the first passage; and an
upstream connector fluidly coupled to the second passage.
2. The apparatus of claim 1, wherein the regulator valve is
disposed in the regulator chamber.
3. The apparatus of claim 1, wherein the regulator comprises a cap
and a base coupled to the cap to define the regulator chamber.
4. The apparatus of claim 1, wherein: the regulator comprises a cap
and a base coupled to the cap to define the regulator chamber; and
the first passage is a first passage through the base and the
second passage is a second passage through the base.
5. The apparatus of claim 1, wherein the regulator valve is
configured to close the first passage if negative pressure in the
regulator chamber is greater than a target negative pressure, and
to open the first passage if negative pressure in the regulator
chamber is less than the target negative pressure.
6. The apparatus of claim 1, wherein the regulator valve comprises
a regulator seal and a regulator spring operatively engaged with
the regulator seal to bias the regulator valve away from the first
passage.
7. The apparatus of claim 6, wherein: the regulator further
comprises a valve seat adjacent to the first passage; the regulator
seal comprises a valve body adapted to sealingly engage the valve
seat; and the regulator spring is operatively engaged with the
valve body to bias the valve body away from the valve seat.
8. The apparatus of claim 1, further comprising a reservoir in
fluid communication with the downstream connector and the first
passage.
9. The apparatus of claim 1, further comprising: a membrane
defining a negative-pressure chamber fluidly coupled to the
downstream connector and to the first passage; and a spring
disposed in the negative-pressure chamber against the membrane to
bias the membrane to a discharged position.
10. An apparatus for collecting fluid from a tissue site, the
apparatus comprising: a canister; and a lid coupled to the canister
to form a collection chamber; an upstream connector fluidly coupled
to the collection chamber; a regulator coupled to the lid, the
regulator comprising a regulator chamber, a first passage fluidly
coupled to the regulator chamber, a second passage fluidly coupled
to the regulator chamber and to the collection chamber, and a
regulator valve configured to regulate fluid flow through the first
passage based on changes to negative pressure in the regulator
chamber; and a downstream connector fluidly coupled to the first
passage.
11. The apparatus of claim 10, wherein the regulator is integral to
the lid.
12. The apparatus of claim 10, wherein the upstream connector and
the downstream connector are integral to the lid.
13. The apparatus of claim 10, wherein the regulator valve is
disposed in the regulator chamber.
14. The apparatus of claim 10, wherein the regulator comprises a
cap and a base coupled to the cap to define the regulator
chamber.
15. The apparatus of claim 10, wherein: the regulator comprises a
cap and a base coupled to the cap to define the regulator chamber;
and the first passage is a first passage through the base and the
second passage is a second passage through the base.
16. The apparatus of claim 10, wherein the regulator valve is
configured to close the first passage if negative pressure in the
regulator chamber is greater than a target negative pressure, and
to open the first passage if negative pressure in the regulator
chamber is less than the target negative pressure.
17. The apparatus of claim 10, further comprising a reservoir in
fluid communication with the downstream connector and the first
passage.
18. The apparatus of claim 10, further comprising: a membrane
defining a negative-pressure chamber fluidly coupled to the
downstream connector and to the first passage; and a spring
disposed in the negative-pressure chamber against the membrane to
bias the membrane to a discharged position.
19.-29. (canceled)
30. A method of applying negative-pressure therapy to a tissue
site, the method comprising: applying a dressing to the tissue
site; fluidly coupling the dressing to a collection chamber of a
container having a regulator; and fluidly coupling the collection
chamber to a negative-pressure source through the regulator.
31. The method of claim 30, further comprising disposing of the
container with the regulator.
32. The method of claim 30, further comprising charging a secondary
negative-pres sure source within the container.
33. The method of claim 32, further comprising disconnecting the
negative-pressure source from the collection chamber and
maintaining negative pressure with the secondary negative-pressure
source.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 16/073,226, entitled "Fluid Container With Pressure
Regulation," filed Jul. 26, 2018, which is the National Stage of
International Application No. PCT/US2017/014832, entitled "Fluid
Container With Pressure Regulation," filed Jan. 25, 2017 and claims
the benefit of U.S. Provisional Patent Application No. 62/288,142,
entitled "Fluid Container With Pressure Regulation," filed Jan. 28,
2016, all of which are incorporated herein by reference for all
purposes.
TECHNICAL FIELD
[0002] The invention set forth in the appended claims relates
generally to tissue treatment systems and more particularly, but
without limitation, to fluid containers with pressure
regulation.
BACKGROUND
[0003] Clinical studies and practice have shown that reducing
pressure in proximity to a tissue site can augment and accelerate
growth of new tissue at the tissue site. The applications of this
phenomenon are numerous, but it has proven particularly
advantageous for treating wounds. Regardless of the etiology of a
wound, whether trauma, surgery, or another cause, proper care of
the wound is important to the outcome. Treatment of wounds or other
tissue with reduced pressure may be commonly referred to as
"negative-pressure therapy," but is also known by other names,
including "negative-pressure wound therapy," "reduced-pressure
therapy," "vacuum therapy," "vacuum-assisted closure," and "topical
negative-pressure," for example. Negative-pressure therapy may
provide a number of benefits, including migration of epithelial and
subcutaneous tissues, improved blood flow, and micro-deformation of
tissue at a wound site. Together, these benefits can increase
development of granulation tissue and reduce healing times.
[0004] While the clinical benefits of negative-pressure therapy are
widely known, improvements to therapy systems, components, and
processes may benefit healthcare providers and patients.
BRIEF SUMMARY
[0005] New and useful systems, apparatuses, and methods for
regulating pressure in a negative-pressure therapy environment are
set forth in the appended claims. Illustrative embodiments are also
provided to enable a person skilled in the art to make and use the
claimed subject matter.
[0006] Various embodiments of a system or apparatus for
negative-pressure treatment are described. The system or apparatus
may include a container configured to collect a fluid from a tissue
site and regulate negative-pressure from a negative-pressure
source. In some embodiments, for example, the container may include
a regulator that receives negative pressure directly from an
unregulated negative-pressure source, such as a wall-suction
outlet. The regulator may regulate down the pressure delivered to a
collection chamber in the container, which may in turn be connected
to a tissue site.
[0007] In some embodiments, a container may include a lid or other
apparatus for enclosing a canister. In general, the apparatus may
comprise a rim configured to sealingly engage the fluid canister to
form a collection chamber. The apparatus may further include a
regulator adapted to regulate negative pressure in the collection
chamber. In some embodiments, the regulator may generally comprise
a regulator chamber, a first passage fluidly coupled to the
regulator chamber, a second passage fluidly coupled to the
regulator chamber, and a regulator valve. A downstream connector
may be fluidly coupled to the first passage, and an upstream
connector may be fluidly coupled to the second passage. In
operation, the downstream connector may be fluidly coupled to a
negative-pressure source, for example, and the upstream connector
may be fluidly coupled to a dressing or other distribution
component. The regulator valve may be configured to regulate fluid
flow through the first passage based on changes to negative
pressure in the regulator chamber. For example, if the downstream
connector is coupled to a source of unregulated negative pressure,
such as a wall-suction port, the regulator can regulate the
negative pressure as it passes through the container to the
dressing. In some embodiments, the regulator valve may be
configured to close the first passage if negative pressure in the
regulator chamber is greater than a target negative pressure, and
to open the first passage if negative pressure in the regulator
chamber is less than the target negative pressure.
[0008] In various embodiments, a negative-pressure treatment system
is also described. The system may have a container having a
collection volume configured to collect fluid from a tissue site.
The system may further have a regulator having a regulator chamber
that is integrated into the container configured to regulate
negative pressure in the container from a reduced pressure provided
by a primary negative-pressure source. A first passage from the
regulator chamber may form a first fluid pathway between the
regulator chamber and the tissue site and a second passage from the
regulator chamber may form a second fluid pathway to the
container.
[0009] The system or apparatus may further have an auxiliary or
secondary negative-pressure source within the container, such as a
collapsible internal reservoir within a canister lid. The reservoir
may be inflated by one or more springs, if not under negative
pressure. The springs may be designed or selected to collapse under
a threshold negative pressure. The reservoir may be fluidly coupled
to a regulator chamber through the second passage. In some
embodiments, the reservoir may comprise or be defined by a flexible
membrane, and a spring may be configured to bias the flexible
membrane away from the regulator chamber. The reservoir may provide
continued delivery of therapy if the container is removed from a
primary negative-pressure source, such as a facility wall-suction
port. A charge indicator may be incorporated into some embodiments
of the container to indicate the state of the reservoir. In some
embodiments, pressure regulation may be mechanical, and pressure
feedback or indicators may be electronic.
[0010] In various embodiments, a method of forming a reduced
pressure treatment system through a container to a tissue site to
remove fluid from the tissue site into a collection volume of the
container is disclosed. The method may comprise connecting a
dressing at the tissue site to an upstream flow connection of the
container and connecting a primary negative-pressure source to a
downstream flow connection of the container. A regulator may be
integrated into the container between the upstream flow connection
and the downstream flow connection to regulate a first reduced
pressure in the waste volume of the container from a second reduced
pressure formed by the primary negative-pressure source. Disclosed
is a regulator system for a low pressure line or vacuum system. The
regulator may be incorporated into a disposable unit, such as a
container system. The regulator may regulate a vacuum source to a
selected pressure.
[0011] The regulator may be incorporated into a container system
that may be interconnected between an unregulated vacuum source and
a tissue site. In particular, the regulator may be placed between
an unregulated vacuum source and a dressing. The dressing may cover
a portion of a wound, such as an ulcer, surgical incision site, or
the like.
[0012] The regulator may be included in a canister or in a lid of a
container system to assist in ensuring removal of the regulator to
maintain proper operation of the regulator through appropriate duty
cycles to maintain a regulated pressure. For example, a disposable
regulator may ensure that the regulator does not become clogged
during use and reduce or eliminate the regulated pressure.
Therefore, the regulator may be incorporated into a container to
allow the container to be disposed once full to allow replacement
with a new container system having a new regulator that is
clean.
[0013] Objectives, advantages, and a preferred mode of making and
using the claimed subject matter may be understood best by
reference to the accompanying drawings in conjunction with the
following detailed description of illustrative embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a functional block diagram of an example
embodiment of a therapy system that can remove waste in accordance
with this specification;
[0015] FIG. 2A is a schematic diagram illustrating additional
details of the container system that may be associated with an
example embodiment of therapy system of FIG. 1, according to
various embodiments;
[0016] FIG. 2B is a cross-sectional view of the container of FIG.
2A along line 2B-2B;
[0017] FIG. 2C is a detail of the container taken from Rectangle 2C
of FIG. 2B;
[0018] FIG. 3 is a detail cross-sectional view of a regulator in an
open position;
[0019] FIG. 4 is a detail cross-sectional view of a regulator in a
closed position; and
[0020] FIG. 5 is a cross-sectional view of a container of FIG. 1,
according to various embodiments.
DESCRIPTION OF EXAMPLE EMBODIMENTS
[0021] The following description of example embodiments provides
information that enables a person skilled in the art to make and
use the subject matter set forth in the appended claims, but may
omit certain details already well-known in the art. The following
detailed description is, therefore, to be taken as illustrative and
not limiting.
[0022] The example embodiments may also be described herein with
reference to spatial relationships between various elements or to
the spatial orientation of various elements depicted in the
attached drawings. In general, such relationships or orientation
assume a frame of reference consistent with or relative to a
patient in a position to receive treatment. As should be recognized
by those skilled in the art, however, this frame of reference is
merely a descriptive expedient rather than a strict
prescription.
[0023] FIG. 1 is a simplified functional block diagram of an
example embodiment of a therapy system 100 that can provide
negative-pressure therapy to a tissue site in accordance with this
specification.
[0024] The term "tissue site" in this context broadly refers to a
wound, defect, or other treatment target located on or within
tissue, including but not limited to, bone tissue, adipose tissue,
muscle tissue, neural tissue, dermal tissue, vascular tissue,
connective tissue, cartilage, tendons, or ligaments. A wound may
include chronic, acute, traumatic, subacute, and dehisced wounds,
partial-thickness burns, ulcers (such as diabetic, pressure, or
venous insufficiency ulcers), flaps, and grafts, for example. The
term "tissue site" may also refer to areas of any tissue that are
not necessarily wounded or defective, but are instead areas in
which it may be desirable to add or promote the growth of
additional tissue. For example, negative pressure may be applied to
a tissue site to grow additional tissue that may be harvested and
transplanted.
[0025] The therapy system 100 may include negative-pressure supply,
and may include or be configured to be coupled to a distribution
component, such as a dressing. In general, a distribution component
may refer to any complementary or ancillary component configured to
be fluidly coupled to a negative-pressure supply in a fluid path
between a negative-pressure supply and a tissue site. A
distribution component is preferably detachable, and may be
disposable, reusable, or recyclable. Distribution components may
include dressings, containers, and fluid conductors, for example.
In FIG. 1, a dressing 102 is illustrative of a distribution
component, which may be fluidly coupled to a negative-pressure
source 104. A dressing may include a cover, a tissue interface, or
both in some embodiments. The dressing 102, for example, may
include a cover 106 and a tissue interface 108.
[0026] A regulator or a controller, such as a regulator 110, may
also be coupled to the negative-pressure source 104. As illustrated
in the example of FIG. 1, the regulator 110 may be fluidly coupled
to the negative-pressure source 104 and to a fluid container, such
as a container 112. In some embodiments, the therapy system 100 may
optionally include sensors to measure operating parameters and
provide feedback signals indicative of the operating parameters.
For example, the negative-pressure source 104 may be electrically
coupled to the regulator 110 to provide feedback signals or
indicators.
[0027] In some embodiments, a dressing interface may facilitate
coupling the negative-pressure source 104 to the dressing 102. For
example, such a dressing interface may be a T.R.A.C..RTM. Pad or
Sensa T.R.A.C..RTM. Pad available from KCI of San Antonio, Tex. The
therapy system 100 may also include a fluid container, such as the
container 112, coupled to the dressing 102 and to the
negative-pressure source 104.
[0028] Components may be fluidly coupled to each other to provide a
path for transferring fluids (i.e., liquid and/or gas) between the
components. For example, components may be fluidly coupled through
a fluid conductor, such as a tube. A "tube," as used herein,
broadly includes a tube, pipe, hose, conduit, or other structure
with one or more lumina adapted to convey a fluid between two ends.
Typically, a tube is an elongated, cylindrical structure with some
flexibility, but the geometry and rigidity may vary. In some
embodiments, components may also be coupled by virtue of physical
proximity, being integral to a single structure, or being formed
from the same piece of material. Moreover, some fluid conductors
may be molded into or otherwise integrally combined with other
components. Coupling may also include mechanical, thermal,
electrical, or chemical coupling (such as a chemical bond) in some
contexts. For example, a tube may mechanically and fluidly couple
the dressing 102 to the container 112 in some embodiments.
[0029] In general, components of the therapy system 100 may be
coupled directly or indirectly. For example, the negative-pressure
source 104 may be directly coupled to the regulator 110, and may be
indirectly coupled to the dressing 102 through the regulator
110.
[0030] The fluid mechanics of using a negative-pressure source to
reduce pressure in another component or location, such as within a
sealed therapeutic environment, can be mathematically complex.
However, the basic principles of fluid mechanics applicable to
negative-pressure therapy are generally well-known to those skilled
in the art, and the process of reducing pressure may be described
illustratively herein as "delivering," "distributing," or
"generating" negative pressure, for example.
[0031] In general, exudates and other fluids flow toward lower
pressure along a fluid path. Thus, the term "downstream" typically
implies something in a fluid path relatively closer to a source of
negative pressure or further away from a source of positive
pressure. Conversely, the term "upstream" implies something
relatively further away from a source of negative pressure or
closer to a source of positive pressure. Similarly, it may be
convenient to describe certain features in terms of fluid "inlet"
or "outlet" in such a frame of reference. This orientation is
generally presumed for purposes of describing various features and
components herein. However, the fluid path may also be reversed in
some applications (such as by substituting a positive-pressure
source for a negative-pressure source) and this descriptive
convention should not be construed as a limiting convention.
[0032] "Negative pressure" generally refers to a pressure less than
a local ambient pressure, such as the ambient pressure in a local
environment external to a sealed therapeutic environment provided
by the dressing 102. In many cases, the local ambient pressure may
also be the atmospheric pressure at which a tissue site is located.
Alternatively, the pressure may be less than a hydrostatic pressure
associated with tissue at the tissue site. Unless otherwise
indicated, values of pressure stated herein are gauge pressures.
Similarly, references to increases in negative pressure typically
refer to a decrease in absolute pressure, while decreases in
negative pressure typically refer to an increase in absolute
pressure. While the amount and nature of negative pressure applied
to a tissue site may vary according to therapeutic requirements,
the pressure is generally a low vacuum, also commonly referred to
as a rough vacuum, between -5 mm Hg (-667 Pa) and -500 mm Hg (-66.7
kPa). Common therapeutic ranges are between -75 mm Hg (-9.9 kPa)
and -300 mm Hg (-39.9 kPa).
[0033] A negative-pressure supply, such as the negative-pressure
source 104, may be a reservoir of air at a negative pressure, or
may be a manual or electrically-powered device that can reduce the
pressure in a sealed volume, such as a vacuum pump, a suction pump,
a wall suction port available at many healthcare facilities, or a
micro-pump, for example. A negative-pressure supply may be housed
within or used in conjunction with other components, such as
sensors, processing units, alarm indicators, memory, databases,
software, display devices, or user interfaces that further
facilitate therapy. For example, in some embodiments, the
negative-pressure source 104 may be combined with other components
into a therapy unit. A negative-pressure supply may also have one
or more supply ports configured to facilitate coupling and
de-coupling the negative-pressure supply to one or more
distribution components.
[0034] The tissue interface 108 can be generally adapted to contact
a tissue site. The tissue interface 108 may be partially or fully
in contact with the tissue site. If the tissue site is a wound, for
example, the tissue interface 108 may partially or completely fill
the wound, or may be placed over the wound. The tissue interface
108 may take many forms, and may have many sizes, shapes, or
thicknesses depending on a variety of factors, such as the type of
treatment being implemented or the nature and size of a tissue
site. For example, the size and shape of the tissue interface 108
may be adapted to the contours of deep and irregular shaped tissue
sites. Moreover, any or all of the surfaces of the tissue interface
108 may have projections or an uneven, course, or jagged profile
that can induce strains and stresses on a tissue site, which can
promote granulation at the tissue site.
[0035] In some embodiments, the tissue interface 108 may be a
manifold. A "manifold" in this context generally includes any
substance or structure providing a plurality of pathways adapted to
collect or distribute fluid across a tissue site under pressure.
For example, a manifold may be adapted to receive negative pressure
from a source and distribute negative pressure through multiple
apertures across a tissue site, which may have the effect of
collecting fluid from across a tissue site and drawing the fluid
toward the source. In some embodiments, the fluid path may be
reversed or a secondary fluid path may be provided to facilitate
delivering fluid across a tissue site.
[0036] In some illustrative embodiments, the pathways of a manifold
may be interconnected to improve distribution or collection of
fluids across a tissue site. In some illustrative embodiments, a
manifold may be a porous foam material having interconnected cells
or pores. For example, cellular foam, open-cell foam, reticulated
foam, porous tissue collections, and other porous material such as
gauze or felted mat generally include pores, edges, and/or walls
adapted to form interconnected fluid channels. Liquids, gels, and
other foams may also include or be cured to include apertures and
fluid pathways. In some embodiments, a manifold may additionally or
alternatively comprise projections that form interconnected fluid
pathways. For example, a manifold may be molded to provide surface
projections that define interconnected fluid pathways.
[0037] The average pore size of a foam may vary according to needs
of a prescribed therapy. For example, in some embodiments, the
tissue interface 108 may be a foam having pore sizes in a range of
400-600 microns. The tensile strength of the tissue interface 108
may also vary according to needs of a prescribed therapy. For
example, the tensile strength of a foam may be increased for
instillation of topical treatment solutions. In one non-limiting
example, the tissue interface 108 may be an open-cell, reticulated
polyurethane foam such as GranuFoam.RTM. dressing or VeraFlo.RTM.
foam, both available from Kinetic Concepts, Inc. of San Antonio,
Tex.
[0038] The tissue interface 108 may be either hydrophobic or
hydrophilic. In an example in which the tissue interface 108 may be
hydrophilic, the tissue interface 108 may also wick fluid away from
a tissue site, while continuing to distribute negative pressure to
the tissue site. The wicking properties of the tissue interface 108
may draw fluid away from a tissue site by capillary flow or other
wicking mechanisms. An example of a hydrophilic foam is a polyvinyl
alcohol, open-cell foam such as V.A.C. WhiteFoam.RTM. dressing
available from Kinetic Concepts, Inc. of San Antonio, Tex. Other
hydrophilic foams may include those made from polyether. Other
foams that may exhibit hydrophilic characteristics include
hydrophobic foams that have been treated or coated to provide
hydrophilicity.
[0039] The tissue interface 108 may further promote granulation at
a tissue site when pressure within the sealed therapeutic
environment is reduced. For example, any or all of the surfaces of
the tissue interface 108 may have an uneven, coarse, or jagged
profile that can induce microstrains and stresses at a tissue site
if negative pressure is applied through the tissue interface
108.
[0040] In some embodiments, the tissue interface 108 may be
constructed from bioresorbable materials. Suitable bioresorbable
materials may include, without limitation, a polymeric blend of
polylactic acid (PLA) and polyglycolic acid (PGA). The polymeric
blend may also include without limitation polycarbonates,
polyfumarates, and capralactones. The tissue interface 108 may
further serve as a scaffold for new cell-growth, or a scaffold
material may be used in conjunction with the tissue interface 108
to promote cell-growth. A scaffold is generally a substance or
structure used to enhance or promote the growth of cells or
formation of tissue, such as a three-dimensional porous structure
that provides a template for cell growth. Illustrative examples of
scaffold materials include calcium phosphate, collagen, PLA/PGA,
coral hydroxy apatites, carbonates, or processed allograft
materials.
[0041] In some embodiments, the cover 106 may provide a bacterial
barrier and protection from physical trauma. The cover 106 may also
be constructed from a material that can reduce evaporative losses
and provide a fluid seal between two components or two
environments, such as between a therapeutic environment and a local
external environment. The cover 106 may be, for example, an
elastomeric film or membrane that can provide a seal adequate to
maintain a negative pressure at a tissue site for a given
negative-pressure source. The cover 106 may have a high
moisture-vapor transmission rate (MVTR) in some applications. For
example, the MVTR may be at least 300 g/m{circumflex over ( )}2 per
twenty-four hours in some embodiments. In some example embodiments,
the cover 106 may be a polymer drape, such as a polyurethane film,
that is permeable to water vapor but impermeable to liquid. Such
drapes typically have a thickness in the range of 25-50 microns.
For permeable materials, the permeability generally should be low
enough that a desired negative pressure may be maintained.
[0042] An attachment device may be used to attach the cover 106 to
an attachment surface, such as undamaged epidermis, a gasket, or
another cover. The attachment device may take many forms. For
example, an attachment device may be a medically-acceptable,
pressure-sensitive adhesive that extends about a periphery, a
portion, or an entire sealing member. In some embodiments, for
example, some or all of the cover 106 may be coated with an acrylic
adhesive having a coating weight between 25-65 grams per square
meter (g.s.m.). Thicker adhesives, or combinations of adhesives,
may be applied in some embodiments to improve the seal and reduce
leaks. Other example embodiments of an attachment device may
include a double-sided tape, paste, hydrocolloid, hydrogel,
silicone gel, or organogel.
[0043] The container 112 is representative of a container,
canister, pouch, or other storage component, which can be used to
manage exudates and other fluids withdrawn from a tissue site. In
many environments, a rigid container may be preferred or required
for collecting, storing, and disposing of fluids. In other
environments, fluids may be properly disposed of without rigid
container storage, and a re-usable container could reduce waste and
costs associated with negative-pressure therapy.
[0044] In operation, the tissue interface 108 may be placed within,
over, on, or otherwise proximate to a tissue site. The cover 106
may be placed over the tissue interface 108 and sealed to an
attachment surface near the tissue site. For example, the cover 106
may be sealed to undamaged epidermis peripheral to a tissue site.
Thus, the dressing 102 can provide a sealed therapeutic environment
proximate to a tissue site, substantially isolated from the
external environment, and the negative-pressure source 104 can
reduce the pressure in the sealed therapeutic environment. Negative
pressure applied across the tissue site through the tissue
interface 108 in the sealed therapeutic environment can induce
macrostrain and microstrain in the tissue site, as well as remove
exudates and other fluids from the tissue site, which can be
collected in container 112.
[0045] FIGS. 2A-2C illustrate additional details that may be
associated with some embodiments of the container 112. With
reference to FIG. 2A, some embodiments of the container 112 may
comprise a canister lid 152 and a canister 154. The canister 154
may be formed of various materials, including metals and/or
polymers. Further, the canister 154 may be opaque, transparent, or
semi-transparent. For example, the canister 154 may be any of a
variety of suction canisters commonly found in health care
facilities, such as suction canisters offered by BEMIS Health Care
Products. Assembled as illustrated in the example of FIG. 2A, the
canister lid 152 may be connected to the canister 154 with an air
tight seal.
[0046] With continuing reference to FIG. 2A and additional
reference to FIG. 2B, the canister 154 can include an external wall
156 that extends from a base wall 158 to an upper edge or rim, such
as the rim 160. The rim 160 can sealingly engage the canister lid
152. For example, the canister lid 152 can include a lid connection
portion or ledge 164 and the canister 154 can include a canister
connection portion or ledge 166. The ledge 164 and the ledge 166
may form a snap fit, threaded connection, adhesive connection, or
other appropriate connections. Generally, the canister lid 152 may
be coupled to the canister 154 to form a collection chamber 170.
The collection chamber 170 is preferably sealed relative to ambient
environment. Further, the seal, such as formed by the ledge 164 and
the ledge 166 is preferably an air-tight seal such that a negative
pressure within the collection chamber 170 may be maintained for a
selected period of time.
[0047] The canister lid 152 may include a first fluid port, such as
a downstream connector 180. For example, the downstream connector
180 may be adapted for coupling with a tube or other fluid
conductor, which can provide a fluid path between the
negative-pressure source 104 and the container 112 as illustrated
in FIG. 1. The canister lid 152 may further include a second fluid
port, such as an upstream connector 182. For example, the upstream
connector 182 may be fluidly coupled to the dressing 102, as
illustrated in FIG. 1.
[0048] In various embodiments, the negative-pressure source 104 may
provide substantially unregulated negative pressure, such as
commonly available through wall ports in many health care
facilities. The canister lid 152 may include various features to
regulate pressure within the collection chamber 170. For example,
in some embodiments, the canister lid 152 may include a regulator
190, which may be an example embodiment of the regulator 110 of
FIG. 1. In various embodiments, the regulator 190 may be integrated
into the lid 152, or may be connected to the lid 152. The regulator
190 may regulate the pressure from the negative-pressure source 104
to provide a pressure within a target range, such as a prescribed
therapy range.
[0049] The regulator 190 can include various portions and generally
may include an upper wall or cap 194, and a lower wall or base 196.
The cap 194 may also have a vent 197. The regulator 190 may also
generally comprise a fluid pathway between the downstream connector
180 and the upstream connector 182. In some embodiments, the fluid
pathway may comprise a series of fluidly coupled passages. For
example, as illustrated in the embodiment of FIG. 2C, the base 196
may include a first passage 198 fluidly coupled to the downstream
connector 180, and a second passage 200, which may be fluidly
coupled to the collection chamber 170.
[0050] The regulator 190 can include various portions to regulate
distribution of negative pressure through the container 112. If the
negative-pressure source 104 is unregulated, for example, the
pressure within the collection chamber 170 may be regulated by the
regulator 190.
[0051] The regulated pressure from the regulator 190 can be a
regulated pressure that is a within a therapeutically acceptable
range of pressure, for example, and may be substantially
independent of the pressure provided by the negative-pressure
source 104. Therefore, the regulator 190 can be interconnected
between the negative-pressure source 104 and the dressing 102 to
provide a target pressure to the dressing 102. Further, the
regulator 190 can be substantially interconnected or included with
the container 112 to provide regulated pressure through the tubing
to the dressing 102 from an unregulated pressure source, such as
the negative-pressure source 104.
[0052] FIG. 3 is a schematic diagram illustrating additional
details that may be associated with some embodiments of the
regulator 190. As illustrated in FIG. 3, the regulator 190 may
include a regulator chamber 210 and a regulator valve 215 disposed
between the cap 194 and the base 196. For example, as shown in the
illustrative embodiment of FIG. 3, the regulator valve 215 may be a
diaphragm valve having a regulator seal 220 and a regulator spring
260. The regulator seal 220 may be a flexible membrane or
partition, such as a thin flexible disk. The regulator seal 220 may
engage the base 196 at an outer edge 224. For example, the
regulator seal 220 can be generally annular or circular, and
configured to engage a similarly shaped portion of the base 196. In
some embodiments, a projection or a protrusion 226 may engage an
annular depression or groove 228 formed into the base 196. The cap
194 can assist in holding the protrusion 226 into the groove 228 to
assist in operation of the seal 220.
[0053] In some embodiments, the regulator seal 220 may comprise a
central portion 222, and a valve body 240 may extend from the
central portion 222. The valve body 240 may be adapted to engage a
valve seat 242 adjacent to the first passage 198 to seal the first
passage 198. For example, an exterior wall or surface 246 of the
valve body 240 can engage one or more surfaces of the valve seat
242 to close the first passage 198. As illustrated in FIG. 3, the
valve body 240 may include an apex 244 to sealingly engage the
valve seat 242.
[0054] The valve body 240 may be formed integrally and as one piece
with the central portion 222. Alternatively, the valve body 240 may
be formed as a separate piece from the central portion 222 and may
be connected to the central portion 222. In various embodiments,
the seal 220 and the valve body 240 may be formed of a flexible or
an elastomeric material, which may include without limitation
medical grade silicone.
[0055] The regulator spring 260 may be operatively engaged with the
regulator seal 220 to bias the valve body 240 away from the first
passage 198, providing an open fluid path between the first passage
198 and the second passage 200. For example, one end of the
regulator spring 260 may be positioned concentrically around the
valve seat 242 while the other end of the regulator spring 260 may
be positioned around the valve body 240. The spring may be formed
of various materials such as medical grade stainless steel, or
other appropriate materials.
[0056] For example, the regulator spring 260 may provide a biasing
force against ambient pressure provided through the vent 197,
urging the valve body toward an open position (as illustrated in
FIG. 3) and allowing fluid communication through the first passage
198. In the open position, the central portion 222 may be moved
into a depression, hollow area, or recess, such as a recess 264
formed by the cap 194.
[0057] FIG. 4 illustrates additional details that may be associated
with some embodiments of the regulator 190 in a closed position. In
a closed position, the valve body 240 is at least moved partially
out of the recess 264 of the cap 194 to close the first passage
198. For example, as illustrated in the embodiment of FIG. 4, the
valve body 240 may sealingly engage the valve seat 242 to
substantially reduce or block fluid communication through the first
passage 198.
[0058] According to various embodiments, the seal 220 may be moved
as an entirety away from the valve seat 242 by the regulator spring
260. Accordingly, as illustrated in FIG. 3, the movement of the
valve body 240 alone away from the valve seat 242 is merely
exemplary. Further, the central portion 222 may be formed of a
flexible material to allow movement of the valve body 240 relative
to the valve seat 242 as discussed above.
[0059] As illustrated in FIGS. 3 and 4, the valve body 240 can move
from an open position, as illustrated in FIG. 3, spaced away from
the valve seat 242, to a closed position, as illustrated in FIG. 4,
engaging the valve seat 242. The regulator spring 260 has a biasing
force that may be selected to actuate the regulator valve 215 at a
target pressure within the regulator chamber 210, which can also be
maintained in the collection chamber 170 through the second passage
200. The biasing force of regulator spring 260 may be selected
based upon various features and therapeutic requirements so that
the regulator valve 215 is actuated at a target pressure. For
example, the regulator spring 260 may be formed of a selected
material, have a selected diameter, turn frequency, or the like to
achieve closure of the regulator valve 215 at a target pressure
within the regulator chamber 210. Further, some embodiments of the
regulator 190 may include a pressure selector to adjust the
regulation pressure. For example, the cap 194 and the base 196 may
be threaded, and may be rotated to vary compression of the
regulator spring 260, or a twist button or other member may engage
the seal 220, including the valve body 240, to apply additional
biasing force or to overcome a part of the biasing force of the
regulator spring 260 to allow calibration of the regulated pressure
in the regulator chamber 210. Accordingly, in some embodiments, the
regulator 190 can regulate negative pressure to be about 75 mm Hg
to about 200 mm Hg.
[0060] In operation, the regulator 190 may be normally open, as
illustrated in FIG. 3, until the negative-pressure source 104 is
connected and activated to distribute negative pressure through the
first passage 198. After the negative-pressure source 104 has been
activated, the absolute pressure within the regulator chamber 210
may be reduced as the seal between the protrusion 226 and the
groove 228 is maintained and the central portion 222 of the seal
220 does not allow gases to pass from an exterior atmosphere into
the regulator chamber 210. The regulator chamber 210 may become
charged as the negative-pressure source 104 continues to draw gases
through the first passage 198. Further, negative pressure can be
distributed through the second passage 200 to the collection
chamber 170 and to the dressing 102 if the regulator 190 is
open.
[0061] If the target pressure is achieved in the regulator chamber
210, the biasing force of the regulator spring 260 may be overcome
and the valve body 240 may move to the closed position and seal
against the valve seat 242, as illustrated in FIG. 4.
[0062] Accordingly, the reduced pressure in the regulator chamber
210 caused by removal of air and gases from the regulator chamber
210 due to the negative-pressure source 104 can be maintained by
the seal 220 until the biasing force of the regulator spring 260 is
overcome and the valve body 240 engages the valve seat 242. The
negative-pressure source 104 can provide unregulated negative
pressure to the regulator chamber 210, and the regulator 190 can
ensure that the negative pressure distributed to the collection
chamber 170 does not exceed a target negative pressure.
[0063] The valve body 240 may be actuated by changes in negative
pressure within the regulator chamber 210. For example, leaks in
the system can cause the negative pressure within the collection
chamber 170 to decrease over time. Because the collection chamber
170 is fluidly coupled to the regulator chamber 210, changes in the
regulator chamber 210 may also be reflected in the collection
chamber 170. The valve body 240 may open if the negative pressure
in the collection chamber 170 decreases enough to allow the biasing
force of the regulator spring 260 to move the valve body 240 from
the valve seat 242.
[0064] Accordingly, the regulator 190, including the valve body
240, the valve seat 242, and the regulator spring 260, can maintain
a target pressure within the collection chamber 170, and the
dressing 102, that may be different from negative pressure provided
by the negative-pressure source 104. In particular, if the
negative-pressure source 104 is unregulated, the regulator 190 may
provide a regulated pressure to the dressing 102, particularly if a
negative pressure from the negative-pressure source 104 is greater
than the target regulated pressure.
[0065] FIG. 5 illustrates details that may be associated with
another example embodiment of the container 112. In the embodiment
of FIG. 5, the container 112 may include the canister 154 and a lid
310. The lid 310 may be similar in many aspects to the canister lid
152. For example, the lid 310 may include the regulator 190,
substantially as illustrated in FIG. 5. The lid 310 may also
include a sealed connection to the canister 154, including a
snap-fit or other appropriate fit at the rim 160 of the canister
154, including a lid connection portion (including a finger 312)
and the canister connection portion 166. The connection of the lid
310 to the canister 154 can be substantially gas-tight to maintain
a negative pressure.
[0066] The lid 310 may further include the downstream connector
180, which can be fluidly coupled to a primary negative-pressure
source such as the negative-pressure source 104. A check valve 314
may be coupled to the downstream connector 180. Further, the lid
310 may include the upstream connector 182 that allows for a
connection to the dressing 102.
[0067] The lid 310 may additionally comprise a secondary
negative-pressure source, such as a reservoir 300. The reservoir
300 may include a piston, flexible wall, bellows, or membrane, such
as a membrane 320, defining a negative-pressure chamber 304. The
membrane 320 may be formed out of an appropriate material that is
sufficiently flexible and substantially fluid impermeable, such as
a medical grade silicone. The membrane 320 may further be formed to
include a color that contrasts with the canister 154 or the lid 310
for viewing a position of the flexible membrane 320.
[0068] One or more springs 324 may bias the membrane 320 to a
discharged position 320b. For example, in some embodiments, the
springs 324 may be disposed in the negative-pressure chamber to
expand the membrane to the discharged position 320b. Negative
pressure in the reservoir 300 may overcome the biasing force of the
springs 324 to allow the membrane 320 to contract to a charged
position 320a.
[0069] The volume of the negative-pressure chamber 304 generally
increases as the membrane 320 moves from the charged position 320a
to the discharged position. The volume of the negative-pressure
chamber 304 in the discharged state may vary to according to
therapeutic requirements, but a volume in a range of about 100
milliliters to about 200 milliliters may be suitable for some
applications. In some embodiments, the canister 154 may be
transparent or may include a window through which the positon of
the membrane 320 may be viewed to determine whether the reservoir
300 is charged. Graduation marks may provide additional indications
of the state of the reservoir 300.
[0070] In some embodiments, the flexible membrane may be coupled to
one or more supports 326 extending into the collection chamber 170.
The membrane 320 may be sealingly engaged to the supports 326 to
maintain a seal between the reservoir 300 and the ambient
environment. In various embodiments, the membrane 320 may be
welded, molded, or adhered to the supports 326. Further, a separate
mechanical fixation member, such as a spring or locking member, may
be used to engage the flexible member against the supports 326.
Thus, the reservoir 300 may maintain a negative-pressure charge
relative to the atmosphere.
[0071] The negative-pressure source 104 can reduce the absolute
pressure within the negative-pressure chamber 304 of the reservoir
300 formed by the flexible membrane 320 and the supports 326 of the
lid 310. As the negative-pressure source 104 continues to reduce
the absolute pressure within the negative-pressure chamber 304, the
pressure within the negative-pressure chamber 304 is reduced
relative to the collection chamber 170, and the flexible membrane
320 moves to compress the springs 324, as illustrated by the solid
line indicating the flexible member charged position 320a and the
solid compressed spring line 324. When compressed, the
negative-pressure chamber 304 has a reduced absolute pressure
relative to an atmospheric pressure. Accordingly, if the
negative-pressure source 104 is disconnected from the downstream
connector 180 or the container 112, such as for movement of the
patient on which the dressing 102 is placed, the check valve 314
may fluidly seal the negative-pressure chamber 304, and the springs
324 can expand the flexible membrane 320 and increase the volume of
the negative-pressure chamber 304 so that the auxiliary reservoir
300 can maintain a negative pressure relative to the dressing 102.
The biasing by the springs 324 to the discharged position 320b can
continue to generate negative-pressure in the negative-pressure
chamber 304 through the second passage 200 relative to the upstream
connector 182 through the regulator 190.
[0072] In an open state of the regulator 190, the first passage 198
may be fluidly coupled to the upstream connector 182 through the
regulator chamber 210, the second passage 200, and the collection
chamber 170. In a closed state of regulator 190, the second passage
200 and the collection chamber 170 may be fluidly isolated from the
first passage 198. As illustrated in FIG. 5, the lid 310 may differ
from the lid 152 by including a baffle 330 adapted to direct
exudate away from the first passage 198 and into the collection
chamber 170. In such an example configuration, exudate may move
along fluid pathway 332 into the collection chamber 170, separating
exudate from gas movement along a fluid pathway 334. Negative
pressure from the reservoir 300 can maintain or ensure reduced
pressure within the collection chamber 170 such that a negative
pressure may be maintained in the dressing 102, at least
temporarily, if the negative-pressure source 104 is disconnected
from the container 112. Further, the regulator 190 can ensure that
the pressure within the collection chamber 170 is regulated,
regardless of whether the reduced pressure is directly from the
negative-pressure source 104 or from the reservoir 300.
[0073] The systems, apparatuses, and methods described herein may
provide significant advantages. For example, a regulator may be
integrated into a fluid collection container, which can be used in
a negative-pressure therapy system to regulate pressure applied to
a tissue site. Such a regulator may be integrated or coupled to a
lid adapted to fit generic canisters commonly available in health
care environments, and may be particularly advantageous in
facilities where unregulated wall suction is the primary source of
negative pressure. The lid and regulator may be removable and
re-usable, but it may be advantageous in some embodiments to weld
or otherwise securely couple the lid to a canister. For example,
securely coupling the lid to the canister can simplify proper
disposal of exudate. Further, a container may additionally or
alternatively include a secondary negative-pressure source, which
can continue to provide therapeutic negative pressure to a tissue
site if a primary negative-pressure source is disconnected or
interrupted.
[0074] While shown in a few illustrative embodiments, a person
having ordinary skill in the art will recognize that the systems,
apparatuses, and methods described herein are susceptible to
various changes and modifications. Moreover, descriptions of
various alternatives using terms such as "or" do not require mutual
exclusivity unless clearly required by the context, and the
indefinite articles "a" or "an" do not limit the subject to a
single instance unless clearly required by the context. Components
may be also be combined or eliminated in various configurations for
purposes of sale, manufacture, assembly, or use. For example, in
some configurations the dressing 102, the negative-pressure source
104, or both may be eliminated or separated from other components
for manufacture or sale. In other example configurations, the
canister lid 152 and the regulator 190 may also be manufactured,
configured, assembled, or sold independently of other
components.
[0075] The appended claims set forth novel and inventive aspects of
the subject matter described above, but the claims may also
encompass additional subject matter not specifically recited in
detail. For example, certain features, elements, or aspects may be
omitted from the claims if not necessary to distinguish the novel
and inventive features from what is already known to a person
having ordinary skill in the art. Features, elements, and aspects
described herein may also be combined or replaced by alternative
features serving the same, equivalent, or similar purpose without
departing from the scope of the invention defined by the appended
claims.
* * * * *