U.S. patent application number 16/504951 was filed with the patent office on 2019-10-31 for instillation cartridge and therapy system for negative-pressure therapy and instillation therapy.
The applicant listed for this patent is KCI Licensing, Inc.. Invention is credited to Christopher Brian LOCKE, James A. LUCKEMEYER, Timothy Mark ROBINSON.
Application Number | 20190328941 16/504951 |
Document ID | / |
Family ID | 53758526 |
Filed Date | 2019-10-31 |
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United States Patent
Application |
20190328941 |
Kind Code |
A1 |
LUCKEMEYER; James A. ; et
al. |
October 31, 2019 |
INSTILLATION CARTRIDGE AND THERAPY SYSTEM FOR NEGATIVE-PRESSURE
THERAPY AND INSTILLATION THERAPY
Abstract
Systems, methods, and apparatuses for providing installation
therapy and negative-pressure therapy are described. The apparatus
includes a housing and a moveable barrier disposed in the housing
to form a dosing chamber and a pressure chamber. The apparatus also
includes a therapy conduit configured to be fluidly coupled to a
pressure source and to a canister. The apparatus further includes a
fluid inlet fluidly coupled to the dosing chamber and configured to
be fluidly coupled to a fluid source and a fluid outlet fluidly
coupled to the dosing chamber and configured to be fluidly coupled
to a dressing. A pressure inlet is fluidly coupled to the therapy
conduit and the pressure chamber; and a check valve is disposed in
the therapy conduit.
Inventors: |
LUCKEMEYER; James A.; (San
Antonio, TX) ; ROBINSON; Timothy Mark;
(Shillingstone, GB) ; LOCKE; Christopher Brian;
(Bournemouth, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KCI Licensing, Inc. |
San Antonio |
TX |
US |
|
|
Family ID: |
53758526 |
Appl. No.: |
16/504951 |
Filed: |
July 8, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14794340 |
Jul 8, 2015 |
10391208 |
|
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16504951 |
|
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62026538 |
Jul 18, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 1/0035 20140204;
A61M 3/022 20140204; A61M 3/0254 20130101; A61M 5/14224 20130101;
A61M 3/0208 20140204; A61M 2205/128 20130101; A61M 1/0088 20130101;
A61M 1/0084 20130101; A61M 1/0058 20130101; A61M 2205/3334
20130101; A61M 3/0216 20140204; A61M 2205/123 20130101; A61M
2205/3337 20130101; A61M 3/0212 20140204 |
International
Class: |
A61M 1/00 20060101
A61M001/00; A61M 5/142 20060101 A61M005/142; A61M 3/02 20060101
A61M003/02 |
Claims
1. An apparatus for providing instillation therapy and
negative-pressure therapy with a pressure source, the apparatus
comprising: a dosing chamber; a pressure chamber fluidly isolated
from the dosing chamber; a diaphragm separating the dosing chamber
from the pressure chamber, the diaphragm configured to move between
a charge position maximizing a volume of the dosing chamber and a
discharge position maximizing a volume of the pressure chamber; a
conduit fluidly coupled to the pressure chamber and configured to
be fluidly coupled to a source of pressure, and a tissue interface;
and a one-way valve fluidly coupled to the conduit and configured
to prevent fluid flow toward the tissue interface.
2. The apparatus of claim 1, wherein the pressure chamber is
configured to receive positive pressure from the pressure
source.
3. The apparatus of claim 1, wherein the pressure chamber is
configured to receive negative pressure from the pressure
source.
4. The apparatus of claim 1, wherein the pressure chamber is
configured to receive positive pressure and negative pressure from
the pressure source.
5. The apparatus of claim 1, wherein the conduit is configured to
receive positive pressure from the pressure source.
6. The apparatus of claim 1, wherein the conduit is configured to
receive negative pressure from the pressure source.
7. The apparatus of claim 1, wherein the conduit is configured to
receive positive pressure and negative pressure from the pressure
source.
8. The apparatus of claim 1, wherein: the pressure source
comprises: a pump having a pump inlet and a pump outlet; a selector
valve fluidly coupled to the pump inlet and the pump outlet; a pump
pressure sensor; a therapy pressure sensor; and a controller
communicatively coupled to the pump, the selector valve, the pump
pressure sensor, and the therapy pressure sensor, the controller
configured to operate the pump and the selector valve; and the
apparatus further comprises: a pressure-sensing conduit configured
to be fluidly coupled to the therapy pressure sensor and the tissue
interface; and the conduit comprises a therapy conduit configured
to be fluidly coupled to the selector valve; wherein the controller
is configured to actuate the selector valve to selectively apply
positive pressure and negative pressure to the pressure
chamber.
9. An apparatus for providing instillation therapy and
negative-pressure therapy with a pressure source, the apparatus
comprising: a therapy conduit configured to be fluidly coupled on a
first end to the pressure source and on a second end to a canister;
a housing having a fluid inlet configured to be fluidly coupled to
a fluid source, a fluid outlet configured to be fluidly coupled to
a dressing, and a pressure inlet fluidly coupled to the therapy
conduit between the first end and the second end; a moveable
barrier disposed in the housing to form a dosing chamber and a
pressure chamber, the fluid inlet and the fluid outlet in fluid
communication with the dosing chamber, and the pressure inlet in
fluid communication with the pressure chamber; and a check valve
fluidly coupled to the therapy conduit between the second end and
the pressure inlet.
10. The apparatus of claim 9, wherein the pressure chamber is
configured to receive positive pressure and negative pressure.
11. The apparatus of claim 9, wherein the therapy conduit is
configured to receive positive pressure and negative pressure from
the pressure source.
12. The apparatus of claim 9, wherein the apparatus is configured
to be fluidly coupled between the pressure source and the
canister.
13. The apparatus of claim 9, further comprising a pressure-sensing
conduit configured to be fluidly coupled to the canister and a
pressure sensor.
14. The apparatus of claim 9, further comprising a biasing element
coupled to the moveable barrier and operable to move the moveable
barrier between a discharge position and a charge position.
15. The apparatus of claim 14, wherein the biasing element
comprises a spring.
16. The apparatus of claim 14, wherein: the biasing element
comprises a spring; the spring is in a loaded position when the
moveable barrier is in the discharge position; and the spring is in
an unloaded position when the moveable barrier is in the charge
position.
17. The apparatus of claim 14, wherein: the biasing element
comprises a spring; the spring is in a loaded position when the
moveable barrier is in the charge position; and the spring is in an
unloaded position when the moveable barrier is in the discharge
position.
18. The apparatus of claim 9, further comprising: a fluid inlet
valve fluidly coupled to the fluid inlet; and a fluid outlet valve
fluidly coupled to the fluid outlet.
19. The apparatus of claim 18, wherein: the fluid inlet valve is a
check valve permitting fluid flow into the dosing chamber; and the
fluid outlet valve is a check valve permitting fluid flow out of
the dosing chamber.
20. A coupling system for a therapy apparatus having multiple
components, the system comprising: a tang coupled to a first
component; and a lever coupled to a second component, the tang
configured to releasably engage the lever to inhibit relative
motion between the first component and the second component, and
the lever operable to permit separation of the first component and
the second component.
21. The system of claim 20, wherein the first component comprises a
pressure source.
22. The system of claim 20, wherein the second component comprises
a cartridge.
23. The system of claim 20, wherein the tang is a first tang, the
lever is a first lever, and the system further comprises: a second
tang coupled to the second component; and a second lever coupled to
a third component, the second tang configured to releasably engage
the second lever to inhibit relative motion between the second
component and the third component, and the second lever operable to
permit separation of the second component from the third
component.
24. The system of claim 23, wherein the third component comprises a
canister.
Description
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/794,340, filed Jul. 8, 2015, which claims
the benefit, under 35 USC .sctn. 119(e), of the filing of U.S.
Provisional Patent Application No. 62/026,538, entitled
"Instillation Cartridge and Therapy System for Negative-Pressure
Therapy and Instillation Therapy," by Robinson et al., filed Jul.
18, 2014, which is 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 a disposable cartridge for use with a
therapy system to provide negative-pressure therapy and
instillation therapy.
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," and "vacuum-assisted closure," 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] In addition, the delivery of therapeutic fluids (e.g. saline
or antibiotic fluids) to the tissue site can also provide benefits
to healing of a tissue site. Treatment of tissue sites with the
delivery of therapeutic fluids may also be referred to as
"instillation therapy." Instillation therapy may assist in cleaning
the tissue site by aiding in the removal of infectious agents or
necrotic tissue. The therapeutic fluids used in instillation
therapy may also provide medicinal fluids, such as antibiotics,
anti-fungals, antiseptics, analgesics, or other similar substances,
to aid in the treatment of a tissue site.
[0005] While the clinical benefits of negative-pressure therapy and
instillation therapy are widely known, the cost and complexity of
negative-pressure therapy and instillation therapy can be a
limiting factor in its application, and the development and
operation of delivery systems, components, and processes continues
to present significant challenges to manufacturers, healthcare
providers, and patients.
BRIEF SUMMARY
[0006] New and useful systems, apparatuses, and methods for
instilling fluids 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. For example, an apparatus for providing
installation therapy and negative-pressure therapy is described.
The apparatus can include a housing and a moveable barrier disposed
in the housing to form a dosing chamber and a pressure chamber. The
apparatus can also include a therapy conduit configured to be
fluidly coupled to a pressure source and to a canister. The
apparatus can further include a fluid inlet fluidly coupled to the
dosing chamber and configured to be fluidly coupled to a fluid
source and a fluid outlet fluidly coupled to the dosing chamber and
configured to be fluidly coupled to a dressing. A pressure inlet
may be fluidly coupled to the therapy conduit and the pressure
chamber, and a check valve is disposed in the therapy conduit.
[0007] In other embodiments, an apparatus for providing
instillation therapy and negative-pressure therapy with a pressure
source is described. The apparatus can include a therapy conduit
configured to be fluidly coupled on a first end to the pressure
source and on a second end to a canister, and a housing having a
fluid inlet configured to be fluidly coupled to a fluid source, a
fluid outlet configured to be fluidly coupled to a dressing, and a
pressure inlet fluidly coupled to the therapy conduit. A moveable
barrier may be disposed in the housing to form a dosing chamber and
a pressure chamber. The dosing chamber and the pressure chamber may
be fluidly isolated from each other. The fluid inlet and the fluid
outlet may be in fluid communication with the dosing chamber, and
the pressure inlet may be in fluid communication with the pressure
chamber. The apparatus may also include a check valve fluidly
coupled to the therapy conduit and the pressure inlet.
[0008] In still other embodiments, a therapy system for providing
instillation therapy and negative-pressure therapy is described.
The system may include a pump having a pump inlet and a pump
outlet. The pump may be configured to draw fluid into the pump
inlet and move fluid out of the pump outlet. The system may also
include a fluid source and an adapter coupled to the pump and the
fluid source. The adapter may include a therapy conduit configured
to be fluidly coupled on a first end to the pump and on a second
end to a canister. The adapter may also include a housing having a
fluid inlet configured to be fluidly coupled to the fluid source, a
fluid outlet configured to be fluidly coupled to a dressing, and a
pressure inlet fluidly coupled to the therapy conduit. A moveable
barrier may be disposed in the housing to form a dosing chamber and
a pressure chamber. The dosing chamber and the pressure chamber may
be fluidly isolated from each other. The fluid inlet and the fluid
outlet may be in fluid communication with the dosing chamber, and
the pressure inlet may be in fluid communication with the pressure
chamber. The adapter may also include a check valve fluidly coupled
to the therapy conduit and the pressure inlet. The system may
further include a selector valve fluidly coupled to the pump inlet
and the pump outlet. The selector valve may be configured to be
fluidly coupled to the therapy conduit. The selector valve may have
a first position fluidly coupling the pump inlet to the therapy
conduit and a second position fluidly coupling the pump outlet to
the therapy conduit.
[0009] In yet other embodiments, a method for providing
instillation therapy and negative-pressure therapy is described. A
pressure source having a selector valve, a canister, a fluid
source, a dressing, and an adapter may be provided. The adapter may
include a therapy conduit and a housing having a fluid inlet, a
fluid outlet, and a pressure inlet fluidly coupled to the therapy
conduit. The adapter may also include a moveable barrier disposed
in the housing to form a dosing chamber and a pressure chamber. The
dosing chamber and the pressure chamber may be fluidly isolated
from each other. The fluid inlet and the fluid outlet may be in
fluid communication with the dosing chamber, and the pressure inlet
may be in fluid communication with the pressure chamber. A check
valve may be fluidly coupled to the therapy conduit and the
pressure inlet. The therapy conduit may be fluidly coupled to the
pressure source and the canister, the fluid source may be fluidly
coupled to the fluid inlet, and the fluid outlet may be fluidly
coupled to the dressing. The selector valve may be operated to
select a therapy mode, and the pressure source may be operated in
response to the therapy mode selection.
[0010] 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
[0011] FIG. 1 is a functional block diagram of an example
embodiment of a therapy system that can provide instillation fluid
in accordance with this specification;
[0012] FIG. 2 is a schematic sectional diagram illustrating
additional details that may be associated with an example
embodiment of a cartridge of the therapy system of FIG. 1;
[0013] FIG. 3 is a schematic sectional diagram illustrating
additional details that may be associated with a pressure source of
the therapy system of FIG. 1;
[0014] FIG. 4 is a schematic sectional diagram illustrating
additional details that may be associated with operations of an
example embodiment of the cartridge of FIG. 2; and
[0015] FIG. 5 is a schematic diagram illustrating additional
details that may be associated with an attachment system of the
therapy system of FIG. 1.
DESCRIPTION OF EXAMPLE EMBODIMENTS
[0016] 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.
[0017] 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. However, as should be
recognized by those skilled in the art, this frame of reference is
merely a descriptive expedient rather than a strict
prescription.
[0018] FIG. 1 is a simplified functional block diagram of an
example embodiment of a therapy system 100 that can provide
instillation therapy and negative-pressure therapy in accordance
with this specification. The therapy system 100 may include a
dressing and a pressure source. For example, a dressing 102 may be
fluidly coupled to a pressure source 104, as illustrated in FIG. 1.
A dressing generally includes a cover and a tissue interface. The
dressing 102, for example, includes a cover 108, and a tissue
interface 110. The therapy system 100 may also include a container,
such as a canister 113, fluidly coupled to the dressing 102 and to
the pressure source 104. In some embodiments, the therapy system
100 may further include an adapter for fluid instillation, such as
a cartridge 112, fluidly coupled to the dressing 102 and the
pressure source 104. In some embodiments, the cartridge 112 may be
fluidly coupled between the pressure source 104 and the canister
113. In some embodiments, the cartridge 112 may be directly fluidly
coupled to both the canister 113 and the dressing 102. In some
embodiments, a fluid source, such as a fluid source 118, may be
fluidly coupled to the cartridge 112.
[0019] In general, components of the therapy system 100 may be
coupled directly or indirectly. For example, the pressure source
104 may be directly coupled to the canister 113 and indirectly
coupled to the dressing 102 through the canister 113. Components
may be fluidly coupled to each other to provide a path for
transferring fluids (i.e., liquid and/or gas) between the
components.
[0020] In some embodiments, for example, components may be fluidly
coupled through a tube. A "tube," as used herein, broadly refers to
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 additionally or alternatively be coupled by virtue
of physical proximity, being integral to a single structure, or
being formed from the same piece of material. Coupling may also
include mechanical, thermal, electrical, or chemical coupling (such
as a chemical bond) in some contexts.
[0021] In operation, the tissue interface 110 may be placed within,
over, on, or otherwise proximate to a tissue site. The cover 108
may be placed over the tissue interface 110 and sealed to tissue
near the tissue site. For example, the cover 108 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 pressure source 104 can reduce the pressure in the sealed
therapeutic environment. Negative pressure applied across the
tissue site through the tissue interface 110 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 and disposed of
properly.
[0022] The fluid mechanics of using a 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.
[0023] In general, exudates and other fluids flow toward lower
pressure along a fluid path. Thus, the term "downstream" typically
refers to a position in a fluid path relatively closer to a
pressure source, and conversely, the term "upstream" refers to a
position relatively further away from a pressure source. 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 of therapy systems herein. However, the fluid path
may also be reversed in some applications (such as by substituting
a positive-pressure source for a pressure source) and this
descriptive convention should not be construed as a limiting
convention.
[0024] The term "tissue site" in this context broadly refers to a
wound or defect 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 used in certain tissue areas to grow
additional tissue that may be harvested and transplanted to another
tissue location.
[0025] "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. "Positive pressure" generally refers to a pressure
greater than a local ambient pressure. References to increases in
positive pressure typically refer to an increase in absolute
pressure, while decreases in positive pressure typically refer to a
decrease in absolute pressure.
[0026] A pressure source, such as the 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 pump, a charge pump, a wall charge port
available at many healthcare facilities, or a micro-pump, for
example. A pressure source 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
negative-pressure therapy. 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).
[0027] A pressure source may also be a reservoir of air at a
positive pressure, or may be a manual or electrically-powered
device that can increase the pressure in a sealed volume, such as a
pump, a suction pump, a wall suction port available at many
healthcare facilities, or a micro-pump, for example. A pressure
source 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. While the amount and nature of
positive pressure applied by a pressure source may vary, the
pressure is generally between 5 mm Hg (667 Pa) and 500 mm Hg (66.7
kPa) and commonly applied at about 100 mm Hg.
[0028] The tissue interface 110 can be generally adapted to contact
a tissue site. The tissue interface 110 may be partially or fully
in contact with the tissue site. If the tissue site is a wound, for
example, the tissue interface 110 may partially or completely fill
the wound, or may be placed over the wound. The tissue interface
110 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 110
may be adapted to the contours of deep and irregular shaped tissue
sites.
[0029] In some embodiments, the tissue interface 110 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. For example, a
manifold may be adapted to receive negative pressure from a source
and distribute the 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.
[0030] In some illustrative embodiments, the pathways of a manifold
may be channels interconnected to improve distribution or
collection of fluids across a tissue site. 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 pathways. Liquids, gels, and other foams may also include or
be cured to include apertures and flow channels. In some
illustrative embodiments, a manifold may be a porous foam material
having interconnected cells or pores adapted to uniformly (or
quasi-uniformly) distribute negative pressure to a tissue site. The
foam material may be either hydrophobic or hydrophilic. In one
non-limiting example, a manifold may be an open-cell, reticulated
polyurethane foam such as GranuFoam.RTM. dressing available from
Kinetic Concepts, Inc. of San Antonio, Tex.
[0031] In an example in which the tissue interface 110 may be made
from a hydrophilic material, the tissue interface 110 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 110 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.
[0032] The tissue interface 110 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 110 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
110.
[0033] In some embodiments, the tissue interface 110 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 110 may
further serve as a scaffold for new cell-growth, or a scaffold
material may be used in conjunction with the tissue interface 110
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.
[0034] In some embodiments, the cover 108 may provide a bacterial
barrier and protection from physical trauma. The cover 108 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 108 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 pressure
source. In some example embodiments, the cover 108 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.
[0035] An attachment device may be used to attach the cover 108 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 108 may be coated with an acrylic
adhesive having a coating weight between 25-65 grams per square
meter (gsm). 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.
[0036] The canister 113 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. The canister 113
is also representative of a fluid management device that is
operable to regulate the delivery of instillation fluid.
[0037] The dressing 102 may also be used to provide a sealed
therapeutic environment for instillation therapy. Instillation
therapy may include the slow introduction of a solution to a tissue
site. The solution may be used to provide moisture to the tissue
site, to provide warmth or cold to the tissue site, to provide a
drug to the tissue site, to soak a tissue site, or to provide
another substance to the tissue site. Often, different types of
instillation therapy may require a different type of instillation
fluid to achieve a desired effect. For example, a first type of
fluid may provide moisture to the tissue site. A different type of
fluid may supply a drug to the tissue site. Many times, the need
for different types of fluid to treat the tissue site may make
instillation therapy time consuming to administer.
[0038] Some patients may experience improved outcomes with a
combined treatment that includes using both negative-pressure
therapy and instillation therapy. Existing therapy systems that
provide instillation or irrigation of a tissue site as well as
negative-pressure therapy can be complicated to use and setup.
Multiple tubes, clamps, and interfaces may often be needed to
properly apply both negative pressure and fluid to the tissue site.
For example, to set up a therapy system having both
negative-pressure therapy and instillation therapy, components for
both systems may be placed proximate to a patient. Unfortunately,
the cost of a combined treatment system can be prohibitive in many
clinical environments, reducing the likelihood that a patient may
receive the benefits of a combined system.
[0039] In many clinical environments, a dedicated negative-pressure
therapy system provides negative-pressure therapy to a tissue site.
The dedicated negative-pressure therapy system may be positioned
proximate to a patient receiving negative-pressure therapy and the
dedicated negative-pressure therapy system may be fluidly coupled
to a tissue site to provide negative-pressure therapy. Similarly,
instillation therapy often relies on a dedicated instillation
therapy system to provide instillation therapy to a tissue site.
The dedicated instillation therapy system may also be positioned
proximate to a patient receiving instillation therapy, and the
dedicated instillation therapy device may be fluidly coupled to a
tissue site to provide instillation therapy. Having both
negative-pressure therapy system components and instillation
therapy system components proximate to a patient may make the area
around the patient cluttered, which can lead to negative outcomes
for the patient.
[0040] Both dedicated negative-pressure therapy systems and
dedicated instillation therapy systems may be expensive. Generally,
given the costs associated with negative-pressure therapy and
instillation therapy, medical facilities may not be willing to
purchase both a dedicated negative-pressure therapy system and a
dedicated instillation therapy system. As a result, some clinical
facilities may choose to forgo some types of clinical treatment.
For example, some clinical facilities may maintain a dedicated
negative-pressure therapy system to provide negative-pressure
therapy. If a patient requires instillation therapy, a clinician
may be required to physically administer instillation therapy, such
as with a syringe. Application of instillation therapy in this
manner may also require the clinician to remove the dressing, which
can cause pain to the patient and potentially increase infection
risks. Physical administration of instillation therapy can require
a significant investment of clinician time, increase the likelihood
of misapplication of therapy, and potentially increase the risk of
infection of a tissue site.
[0041] Some clinical facilities employ multi-channel dedicated
negative-pressure therapy systems. A multi-channel
negative-pressure therapy system may be capable of providing
negative-pressure therapy to more than one tissue site at a time. A
multi-channel negative-pressure therapy system may be large and
inhibit placement of other devices near a patient. If instillation
therapy is also needed, it may be difficult to place a dedicated
instillation therapy system proximate to a patient. Consequently, a
clinician may be required to physically administer instillation
therapy, which can cause some or all of the complications
previously described.
[0042] The therapy system 100 described herein can solve these
problems and others by managing pressure to deliver
negative-pressure therapy and instillation fluids. In some
embodiments, the therapy system 100 can provide negative-pressure
therapy to the tissue site. For example, the cartridge 112 can be
fluidly coupled to the dressing 102 and the pressure source 104,
which can be operated to provide negative pressure to provide
negative-pressure therapy. Additionally, the therapy system 100 can
also provide instillation therapy in some embodiments. For example,
the cartridge 112 can be fluidly coupled to the dressing 102 and
the pressure source 104, which can be operated to provide positive
pressure for instillation therapy. In some embodiments, the therapy
system 100 can provide alternating negative-pressure therapy and
instillation therapy. For example, the pressure source 104 may be
fluidly coupled to the cartridge 112 and the canister 113 and
operated to provide both negative-pressure therapy and instillation
therapy.
[0043] FIG. 2 is a schematic sectional diagram, illustrating
additional details that may be associated with some example
embodiments of the cartridge 112 in a first state. Generally, the
cartridge 112 may have many different shapes and sizes. In some
embodiments, the cartridge 112 may be manufactured to physically
couple to existing negative-pressure therapy products. In some
embodiments, the cartridge 112 may be disposable, single-patient
use, and replaceable every two to three days. In some embodiments,
the cartridge 112 may be about 2 inches thick or less. In some
embodiments, the cartridge may be formed of injection molded
plastic, such as polycarbonate plastic, acrylonitrile butadiene
styrene, or a blend of the two. In some embodiments, the cartridge
112 may have internal components formed of silicone and
thermoplastic elastomer materials and may be sterilized during
assembly.
[0044] The cartridge 112 may have a housing 114. In some
embodiments, the housing 114 may be disposed inside another
container so that the housing 114 may be enclosed in the cartridge
112. In other embodiments, the housing 114 may form an outer
portion of the cartridge 112. In some embodiments, the housing 114
may generally define a chamber and have a structural arrangement to
fluidly isolate the chamber from the ambient environment. In some
embodiments, the housing 114 may be an ellipsoid and form an
ellipsoid chamber having an elliptical cross-section. In other
embodiments, the housing 114 may have other suitable shapes, such
as spherical, cuboid, or amorphous shaped forming similarly shaped
chambers having similarly shaped cross-sections. In some
embodiments, the shape of the chamber may not correspond with the
shape of the housing 114. In some embodiments, the housing 114 may
be formed of plastic, such as EASTAR.TM. DN004 produced by Eastman
Chemical Company. In other embodiments, the housing 114 may be
formed of Terlux.RTM. 2802HD or Terlux.RTM. 2822HD produced by
Styrolution Group GmbH.
[0045] In some embodiments, a barrier may be disposed within the
chamber of the housing 114. A barrier may be a solid object
positioned within the chamber of the housing 114 to divide the
chamber of the housing 114 into two separate fluid chambers. In
some embodiments, a portion or an entirety of a barrier may be
moveable, such as a piston or a diaphragm 124, to adjust respective
volumes of the fluid chambers created by the barrier. In some
embodiments, the diaphragm 124 may be a membrane or a sheet of
semi-flexible material having a periphery. The periphery of the
diaphragm 124 may be coupled to the housing 114 to form a pressure
chamber 126 and a dosing chamber 128. Generally, the periphery of
the diaphragm 124 may be coupled to the housing 114 so that the
pressure chamber 126 is fluidly isolated from the dosing chamber
128. For example, the diaphragm 124 may be sealed to the housing
114, may be welded to the housing 114, or may be otherwise coupled
to the housing 114 to prevent fluid movement across the diaphragm
124. In some embodiments, the diaphragm 124 may be formed of an
elastic or a semi-elastic material. In some embodiments, the
diaphragm 124 may be formed of rubber, thermoplastic, or
polytetrafluoroethlyene.
[0046] In some embodiments, the periphery of the diaphragm 124 may
be coupled to the housing 114 so that the diaphragm 124 may flex
between a discharge position and a charge position. The discharge
position of the diaphragm 124 may be the position of the diaphragm
124 that maximizes the volume of the pressure chamber 126 and
minimizes the volume of the dosing chamber 128. The charge position
of the diaphragm 124 may be the position of the diaphragm 124 that
maximizes the volume of the dosing chamber 128 and minimizes the
volume of the pressure chamber 126. In some embodiments, the
periphery of the diaphragm 124 may be coupled proximate to a center
of a cross-section of the housing 114. For example, the housing 114
may form an ovoid or elliptical-shaped chamber having a transverse
diameter and a conjugate diameter. In some embodiments, the
periphery of the diaphragm 124 may be coupled to the housing 114 so
that the diaphragm 124 coincides with the transverse diameter if
the volumes of the pressure chamber 126 and the dosing chamber 128
are equal, as shown in FIG. 2. In other embodiments, the diaphragm
124 may be coupled to the housing 114 in other locations of the
housing 114.
[0047] In some embodiments, the dimensions of the diaphragm 124,
the pressure chamber 126, and the dosing chamber 128 may be
determined by the amount of fluid needed to provide instillation.
For example, a tissue site may need approximately 5 milliliters of
fluid to be dispensed with each operation of the cartridge 112.
Consequently, the dosing chamber 128 may have a volume of about 5
milliliters if the diaphragm 124 is in the charge position, and the
pressure chamber 126 may have a volume of about 5 milliliters if
the diaphragm 124 is in the discharge position. If the housing 114
is spherical, then the dosing chamber 128 may have a volume given
by:
4/3.pi..times.r.sup.3.ident.V
where r is the radius of a spherical housing 114 in millimeters and
V is the volume of the spherical housing 114 in milliliters. For an
exemplary 5 milliliter volume, the radius of the dosing chamber 128
if the diaphragm 124 is in the charge position is about 10.6
millimeters. In some embodiments, the diaphragm 124 may have a
radius approximately equal to the radius of the dosing chamber 128
if the diaphragm 124 is in the charge position. Similarly, the
pressure chamber 126 may have a radius of about 10.6 millimeters if
the diaphragm 124 is in the discharge position. In some
embodiments, the volume of the dosing chamber 128 if the diaphragm
124 is in the charge position is between about 5 milliliters and
about 10 milliliters. In other embodiments, the volume of the
dosing chamber 128 may be varied as needed to administer a
therapeutic amount of fluid to a tissue site.
[0048] In some embodiments, the housing 114 may be formed of two
sheets of a polymer film having peripheral portions. The peripheral
portions of each sheet may be coupled together, such as by welding,
adhering, or otherwise securing the peripheral portions of each
sheet to each other. In some embodiments, a third sheet of polymer
material may be disposed between the first sheet and the second
sheet of polymer material. The third sheet may have peripheral
portions coupled to the peripheral portions of the first and second
sheet of polymer material to form the diaphragm 124, the pressure
chamber 126, and the dosing chamber 128.
[0049] In some embodiments, the housing 114 may have a pressure
inlet 122. The pressure inlet 122 may be a fluid passage formed in
the housing 114 to provide fluid communication with the pressure
chamber 126. In some embodiments, the pressure inlet 122 may be a
tube having at least one lumen. The tube may be coupled to the
housing 114 so that the lumen of the tube is in fluid communication
with the pressure chamber 126. In some embodiments, the pressure
inlet 122 may be further fluidly coupled to the pressure source
104.
[0050] In some embodiments, the diaphragm 124 may be biased to the
charge position. For example, a biasing element may be disposed in
the pressure chamber 126 to bias the diaphragm 124 to the discharge
position. A biasing element may be a spring 130, for example. The
spring 130 may have a first end coupled to the housing 114 and a
second end coupled to the diaphragm 124. The spring 130 may have an
unloaded position and a loaded position. Generally, if no external
force is acting on the spring 130, the spring 130 is in the
unloaded position. If the spring 130 is compressed or extended, the
spring 130 may be in the loaded position. Generally, a spring may
exert a reactive force in response to displacement from the
unloaded position. The reactive force is generally proportional to
the distance a spring is either compressed or extended if an
external force loads the spring. As shown in FIG. 2, the spring 130
may be unloaded.
[0051] In some embodiments, the biasing element may be a foam
disposed in the pressure chamber 126. In some embodiments, the foam
may be an open-cell reticulated foam having a spring rate similar
to the spring 130. In some embodiments, for example, if the housing
114 comprises a cylindrical construction, the foam may be
configured to compress along a length of the cylinder in response
to the application of negative pressure.
[0052] In some embodiments, the housing 114 may include a fluid
inlet 116. The fluid inlet 116 may be a fluid passage coupled to
the housing 114. In some embodiments, the fluid inlet 116 may be a
tube having at least one lumen. The tube may be coupled to the
housing 114 so that the at least one lumen of the tube is in fluid
communication with the dosing chamber 128. In some embodiments, the
fluid inlet 116 may be further fluidly coupled to a fluid source
118. The fluid source 118 may be a reservoir of fluid, such as
instillation fluid, for example. In some embodiments, the fluid
source 118 may be a reservoir of fluid suspended from an
intravenous pole proximate to the pressure source 104 or the
cartridge 112. In some embodiments, the fluid source 118 may an
intravenous bag having instillation fluid stored therein.
[0053] In some embodiments, a valve 134 may be fluidly coupled to
the fluid inlet 116. In some embodiments, the valve 134 may be
coupled to the housing 114 and the fluid inlet 116 may be coupled
to the valve 134 so that the valve 134 is fluidly coupled between
the fluid inlet 116 and the fluid source 118. In other embodiments,
the valve 134 may be coupled in other locations. In some
embodiments, the valve 134 is a check valve. A check valve may be a
valve that permits one-way flow of fluid through the valve. In some
embodiments, the valve 134 may be a spring-loaded check valve
having a cracking pressure that is responsive to a low vacuum. For
example, the valve 134 may open in response to a pressure
differential of less than about 125 mm Hg negative pressure. In
some embodiments, the valve 134 may be fluidly coupled to the fluid
inlet 116 to permit fluid flow into the dosing chamber 128 and
prevent fluid flow from the dosing chamber 128.
[0054] In some embodiments, the cartridge 112 may also have a fluid
outlet 120. The fluid outlet 120 may be a fluid passage coupled to
the housing 114 to provide fluid communication with the dosing
chamber 128. In some embodiments, the fluid outlet 120 may be a
tube having at least one lumen. The tube may be coupled to the
housing 114 so that a lumen is in fluid communication with the
dosing chamber 128. In some embodiments, the fluid outlet 120 may
be further fluidly coupled to a dressing, such as the dressing 102.
If the fluid outlet 120 is fluidly coupled to the dressing 102, the
dressing 102 may be in fluid communication with the dosing chamber
128 through the fluid outlet 120.
[0055] In some embodiments, a valve 132 may be fluidly coupled to
the fluid outlet 120. In some embodiments, the valve 132 may be
coupled to the fluid outlet 120 so that the valve 132 allows fluid
flow through the fluid outlet 120. In other embodiments, the valve
132 may be coupled in other locations. In some embodiments, the
valve 132 is a check valve. A check valve may be a valve that
permits one-way flow of fluid through the valve. In some
embodiments, the valve 132 may be a spring-loaded check valve
having a cracking pressure that is responsive to low positive
pressures. For example, the valve 132 may open in response to a
pressure differential of less than about 125 mm Hg positive
pressure. In some embodiments, the valve 132 may be fluidly coupled
to the fluid outlet 120 to prevent fluid flow into the dosing
chamber 128 through the fluid outlet 120 and permit fluid flow from
the dosing chamber 128. In some embodiments, the valve 132 may be a
vacuum occluder configured to prevent or limit fluid flow through
the fluid outlet 120 if there is a negative pressure in the dosing
chamber 128.
[0056] In some embodiments, the cartridge 112 may include a
pressure-sensing conduit 140. The pressure-sensing conduit 140 may
be a tube or other fluid passage extending through the cartridge
112. In some embodiments, the pressure-sensing conduit 140 may have
a first end 137 configured to be fluidly coupled to the pressure
source 104 and a second end 139 configured to be fluidly coupled to
the canister 113. Generally, the pressure-sensing conduit 140 may
allow fluid communication through the cartridge 112. In some
embodiments, a pressure sensor may be fluidly coupled to the first
end 137 of the pressure-sensing conduit 140. If the canister 113 is
fluidly coupled to the second end 139 of the pressure-sensing
conduit 140, the pressure in the canister 113 may be fluidly
communicated through the pressure-sensing conduit 140 to the
pressure sensor of the pressure source 104. In some embodiments,
the pressure-sensing conduit 140 may include one or more
hydrophobic filters or odor control activated carbon filters.
[0057] In some embodiments, the cartridge 112 may also include a
therapy conduit 142. The therapy conduit 142 may be a tube or other
fluid passage extending through the cartridge 112. In some
embodiments, the therapy conduit 142 may have a first end 141
configured to be fluidly coupled to the pressure source 104 and a
second end 143 configured to be fluidly coupled to the canister
113. Generally, the therapy conduit 142 may allow fluid
communication through the cartridge 112. In some embodiments, the
pressure source 104 may be fluidly coupled to the first end 141 of
the therapy conduit 142. If the canister 113 is fluidly coupled to
the second end 143 of the therapy conduit 142, the pressure source
104 may be operated to move fluid through the therapy conduit 142.
In some embodiments, the pressure inlet 122 may be fluidly coupled
to the therapy conduit 142. In some embodiments, the therapy
conduit 142 may include one or more hydrophobic filters or odor
control activated carbon filters.
[0058] In some embodiments, a valve 144 may be fluidly coupled to
the therapy conduit 142. The valve 144 may be fluidly coupled
between the pressure inlet 122 and the second end 143 of the
therapy conduit 142. In some embodiments, the valve 144 may be a
check valve configured to permit fluid flow from the second end 143
of the therapy conduit 142 to the first end 141 of the therapy
conduit 142 and prevent fluid flow from the first end 141 of the
therapy conduit 142 to the second end 143 of the therapy conduit
142. In some embodiments, the valve 144 may be a reed type valve. A
reed valve may be a check valve having a flap covering an opening.
Flow through the reed valve in a first direction may move the flap
away from the opening, and flow through the reed valve in a second
direction that is opposite the first direction may move the flap
into tighter contact with the opening, preventing fluid flow. A
reed valve may provide almost no pressure drop and may be
inexpensive to manufacture.
[0059] FIG. 3 is a schematic view, illustrating additional details
that may be associated with some embodiments of the pressure source
104. In some embodiments, the pressure source 104 may include a
pump 146. The pump 146 may be fluidly coupled to a selector valve
148 and communicatively coupled to a controller 152. The selector
valve 148 may be further fluidly coupled to a vent 150 and a pump
pressure sensor 154. The selector valve 148 and the pump pressure
sensor 154 may also be communicatively coupled to the controller
152. In some embodiments, the pressure source 104 may also include
a vent valve 156 that is fluidly coupled to the pump pressure
sensor 154 and a therapy port 162. The vent valve 156 may also be
communicatively coupled to the controller 152. In some embodiments,
the pressure source 104 may further include a therapy-pressure
sensor 158 fluidly coupled to a pressure-relief valve 160 and a
pressure-sensing port 164. The therapy-pressure sensor 158 and the
pressure-relief valve 160 may be further fluidly coupled to the
controller 152. The vent valve 156 and the pressure-relief valve
160 may each be further fluidly coupled to the ambient environment,
such as to the vent 150.
[0060] In some embodiments, the pump 146 may have a pump inlet 145
and a pump outlet 147. The pump inlet 145 may be a fluid connection
through which the pump 146 draws fluid into the pump 146. The pump
outlet 147 may be a fluid connection through which the pump forces
fluid out of the pump 146. In some embodiments, both the pump inlet
145 and the pump outlet 147 may be fluidly coupled to the selector
valve 148. In some embodiments, the pump 146 may be a diaphragm
pump driven by an electric motor. A diaphragm pump may be a
positive displacement pump formed from a chamber having a
reciprocating diaphragm. The chamber may have an inlet and an
outlet, each having a valve operable to permit flow in one
direction. The reciprocating diaphragm may form a portion of the
chamber. The reciprocating action of the diaphragm can cause the
volume of the chamber to change, drawing fluid into the chamber
when the volume is increased and forcing fluid out of the chamber
when the volume is decreased. In other embodiments, the pump 146
may be other pump types operable to generate negative pressures as
described herein. For example, the pump 146 may be a reversible
pump capable of drawing fluid through both the pump inlet 145 and
the pump outlet 147.
[0061] In some embodiments, the pump 146 may have a free-air-flow
capacity between about 7 liters per minute (lpm) to about 9 lpm.
Free-air-flow capacity may refer to the volume of air that may be
moved by a pump when the pump is operated in a free space. In some
embodiments, the pump 146 may be configured to operate at about 2
lpm. In some embodiments, a Parker Hannifin Corporation BTC-IIS
Diaphragm Pump may be used. In some embodiments, a Thomas Products
Division, Manufacturer Part No. 14210001 type diaphragm pump may be
used.
[0062] A pressure sensor, such as the pump pressure sensor 154 or
the therapy-pressure sensor 158, may be a piezoresistive strain
gauge, a capacitive sensor, an electromagnetic sensor, a
piezoelectric sensor, an optical sensor, or a potentiometric
sensor, for example. In some embodiments, a pressure sensor can
measure a strain caused by an applied pressure. A pressure sensor
may be calibrated by relating a known amount of strain to a known
pressure applied. The known relationship may be used to determine
an unknown applied pressure based on a measured amount of strain.
In some embodiments, a pressure sensor may include a receptacle
configured to receive an applied pressure.
[0063] Generally, a "valve," such as the vent valve 156, the
pressure-relief valve 160, or the selector valve 148, may be a
device configured to selectively permit fluid flow through the
device. A valve may be a ball valve, a gate valve, a butterfly
valve, or other valve type that may be operated to control fluid
flow through the valve. Generally, a valve may include a valve body
having a flow passage, a valve member disposed in the flow passage
and operable to selectively block the flow passage, and an actuator
configured to operate the valve member. The flow passage may have
an inlet and an outlet. An actuator may be configured to position
the valve member in a closed position, preventing fluid flow
through the flow passage of the valve; an open position, permitting
fluid flow through the fluid passage of the valve; or a metering
position, permitting fluid flow through the flow passage of the
valve at a selected flow rate. In some embodiments, the actuator
may be a mechanical actuator configured to be operated by an
operator. In some embodiments, the actuator may be an
electromechanical actuator configured to be operated in response to
the receipt of a signal input, such as a solenoid valve. For
example, the actuator may include an electrical motor configured to
receive a signal from a controller. In response to the signal, the
electrical motor of the actuator may move the valve member of the
valve. In some embodiments, the actuator may be a pneumatically
operated actuator configured to be operated in response to receipt
of a pneumatic input. In some embodiments, a pneumatic input may be
negative pressure or positive pressure provided by a pump.
[0064] A flow capacity for a valve may be selected to minimize
pressure drop across the valve while providing a desired flow rate.
In some embodiments, a valve may be selected to provide about 2 lpm
flow through the valve. In some embodiments, a valve may be a pinch
valve. A pinch valve may be a portion of a tube having a clamping
device positioned to selectively compress the tube to block passage
of fluid through the tube. In some embodiments, the portion of a
tube may be a tube formed of an elastomer. In some embodiments, the
portion of a tube may be a tube formed of a silicone.
[0065] In some embodiments, the selector valve 148 may be a
four-way valve having four ports so that up to four devices may be
directly fluidly coupled to the selector valve 148. For example,
the selector valve 148 may be fluidly coupled to both the pump
inlet 145 and the pump outlet 147 of the pump 146, as well as the
pump pressure sensor 154 and the vent 150. Generally, a four-way
valve may have four ports and two fluidly isolated passages
extending through the four-way valve. Each passage may fluidly
couple to separate ports to provide two flow paths through the
four-way valve. The passages may then be moved to fluidly couple
two different ports to provide two different flow paths through the
four-way valve. In some embodiments, the selector valve 148 may be
operable to fluidly couple the pump inlet 145 to the therapy port
162 and the pump outlet 147 to the vent 150 in a first position.
The selector valve 148 may be operated to fluidly couple the pump
inlet 145 to the vent 150 and the pump outlet 147 to the therapy
port 162 in a second position. In some embodiments, the selector
valve 148 may be a solenoid operated four-way valve produced by
MAC.RTM. Valves. In other embodiments, the selector valve 148 may
be a manually operated valve. In some embodiments, the selector
valve 148 may accommodate about 2 lpm flow with a minimal pressure
drop.
[0066] The controller 152 may be communicatively coupled to the
pump 146, the selector valve 148, the pump pressure sensor 154, the
vent valve 156, the therapy-pressure sensor 158, and the
pressure-relief valve 160. The controller 152 may be operable to
actuate the pump 146, the selector valve 148, the pump pressure
sensor 154, the vent valve 156, the therapy-pressure sensor 158,
and the pressure-relief valve 160 to provide negative-pressure
therapy and instillation therapy.
[0067] As used herein, communicative coupling may refer to a
coupling between components that permits the transmission of
signals between the components. In some embodiments, the signals
may be discrete or continuous signals. A discrete signal may be a
signal representing a value at a particular instance in a time
period. A plurality of discrete signals may be used to represent a
changing value over a time period. A continuous signal may be a
signal that provides a value for each instance in a time period.
The signals may also be analog signals or digital signals. An
analog signal may be a continuous signal that includes a time
varying feature that represents another time varying quantity. A
digital signal may be a signal composed of a sequence of discrete
values.
[0068] In some embodiments, communicative coupling between a
controller and other devices may be one-way communication. In
one-way communication, signals may only be sent in one direction.
For example, a sensor may generate a signal that may be
communicated to a controller, but the controller may not be capable
of sending a signal to the sensor. In some embodiments,
communicative coupling between a controller and another device may
be two-way communication. In two-way communication, signals may be
sent in both directions. For example, a controller and a user
interface may be communicatively coupled so that the controller may
send and receive signals from the user interface. Similarly, a user
interface may send and receive signals from a controller. In some
embodiments, signal transmission between a controller and another
device may be referred to as the controller operating the device.
For example, interaction between a controller and a valve may be
referred to as the controller: operating the valve; placing the
valve in an open position, a closed position, or a metering
position; and opening the valve, closing the valve, or metering the
valve.
[0069] A controller, such as the controller 152, may be a computing
device or system, such as a programmable logic controller, or a
data processing system, for example. In some embodiments, a
controller may be configured to receive input from one or more
devices, such as a user interface, a sensor, or a flow meter, for
example. In some embodiments, a controller may receive input, such
as an electrical signal, from an alternative source, such as
through an electrical port, for example.
[0070] In some embodiments, a controller may be a data processing
system. A data processing system suitable for storing and/or
executing program code may include at least one processor coupled
directly or indirectly to memory elements through a system bus. The
memory elements can include local memory employed during actual
execution of the program code, bulk storage, and cache memories
which provide temporary storage of at least some program code in
order to reduce the number of times code is retrieved from bulk
storage during execution.
[0071] In some embodiments, a controller may be a programmable
logic controller (PLC). A PLC may be a digital computer configured
to receive one or more inputs and send one or more outputs in
response to the one or more inputs. A PLC may include a
non-volatile memory configured to store programs or operational
instructions. In some embodiments, the non-volatile memory may be
operationally coupled to a battery-back up so that the non-volatile
memory retains the programs or operational instructions if the PLC
otherwise loses power. In some embodiments, a PLC may be configured
to receive discrete signals and continuous signals and produce
discrete and continuous signals in response.
[0072] The pressure source 104 may include a user interface. A user
interface may be a device configured to allow communication between
a controller, such as the controller 152, and an environment
external to a pressure source 104. In some embodiments, an external
environment may include an operator or a computer system configured
to interface with a pressure source 104, for example. In some
embodiments, a user interface may receive a signal from a
controller and present the signal in a manner that may be
understood by an external environment. In some embodiments, a user
interface may receive signals from an external environment and, in
response, send signals to a controller.
[0073] In some embodiments, a user interface may be a graphical
user interface, a touchscreen, or one or more motion tracking
devices. A user interface may also include one or more display
screens, such as a liquid crystal display ("LCD"), lighting
devices, such as light emitting diodes ("LED") of various colors,
and audible indicators, such as a whistle, configured to emit a
sound that may be heard by an operator. A user interface may
further include one or more devices, such as knobs, buttons,
keyboards, remotes, touchscreens, ports that may be configured to
receive a discrete or continuous signal from another device, or
other similar devices; these devices may be configured to permit
the external environment to interact with the user interface. A
user interface may permit an external environment to select a
therapy to be performed with a pressure source 104. In some
embodiments, a user interface may display information for an
external environment such as a duration of therapy, a type of
therapy, an amount of negative pressure being supplied, an amount
of instillation solution being provided, a fluid level of a
container, or a fluid level of a cartridge, for example.
[0074] A pressure source 104 may also include a power source. A
power source may be a device that supplies electric power to an
electric load. A power source may include a battery, a direct
current (DC) power supply, an alternating current (AC) power
supply, a linear regulated power supply, or a switched-mode power
supply, for example. A power supply may supply electric power to a
controller, a sensor, a flow meter, a valve, a user interface, or a
pump, for example.
[0075] The vent 150 may be an opening disposed on an exterior of
the pressure source 104. The vent 150 may be a device configured to
fluidly couple the exterior to an interior of the pressure source
104. The therapy port 162 may be a port disposed on an exterior of
the pressure source 104. The therapy port 162 may be a device
configured to provide a fluid path to an interior of the pressure
source 104. The pressure-sensing port 164 may be a port disposed on
an exterior of the pressure source 104. The pressure-sensing port
164 may be a device configured to provide a fluid path to an
interior of the pressure source 104.
[0076] Some operations of the therapy system 100 may be described
with respect to FIG. 2, FIG. 3, and FIG. 4, which is a schematic
sectional diagram illustrating additional details that may be
associated with some example operations of the cartridge 112 in a
second state. Generally, the first end 141 of the therapy conduit
142 may be fluidly coupled to the therapy port 162. The fluid
coupling may place the therapy conduit 142 in fluid communication
with the vent valve 156, the pump pressure sensor 154, and the
selector valve 148. Similarly, the first end 137 of the
pressure-sensing conduit 140 may be fluidly coupled to the
pressure-sensing port 164. The fluid coupling may place the
pressure-sensing conduit 140 in fluid communication with the
pressure-relief valve 160 and the therapy-pressure sensor 158. The
canister 113 may be fluidly coupled to the second end 143 of the
therapy conduit 142 and the second end 164 of the pressure-sensing
conduit 140.
[0077] In some embodiments, the therapy system 100 may be operated
in a negative-pressure therapy mode. In the negative-pressure
therapy mode, the controller 152 may position the selector valve
148 in the first position so that the pump inlet 145 is in fluid
communication with the pump pressure sensor 154 and the vent valve
156. In the first position, the pump outlet 147 is in fluid
communication with the vent 150. The controller 152 may operate the
pump 146 to draw fluid through the therapy port 162 and the pump
inlet 145, and move fluid out of the pump outlet 147 and the vent
150. Fluid may also be drawn from the canister 113 through the
therapy conduit 142. The valve 144 may be opened to permit fluid
flow from the second end 143 of the therapy conduit 142 to the
first end 141 of the therapy conduit 142. In this manner, the pump
146 may generate a negative pressure in the canister 113 that may
be communicated to the dressing 102. The pump pressure sensor 154
and the therapy-pressure sensor 158 may determine the pressure in
the therapy conduit 142 and the pressure-sensing conduit 140,
respectively, and communicate the pressures to the controller 152.
In response, the controller 152 may adjust the operation of the
therapy system 100 to provide a predetermined negative-pressure
therapy.
[0078] In some embodiments, fluid may also be drawn through the
pressure inlet 122 through the fluid coupling of the pressure inlet
122 with the therapy conduit 142. The fluid movement may also
generate a negative pressure in the pressure chamber 126. The
negative pressure generated in the pressure chamber 126 may cause a
pressure differential across the diaphragm 124, urging the
diaphragm 124 toward the pressure inlet 122 and the charge
position, as shown in FIG. 2. In some embodiments, fluid may flow
from the fluid source 118 into the dosing chamber 128 in response
to the movement of the diaphragm 124 to the charge position.
[0079] At the conclusion of negative-pressure therapy, the
controller 152 may operate the vent valve 156 and the
pressure-relief valve 160 to equalize the pressure in the canister
113 and the dressing 102 to the ambient pressure. For example, the
pressure-relief valve 160 may be opened to permit fluid to flow
from the ambient environment into the canister 113 and the dressing
102, decreasing the negative-pressure in the canister 113 and the
dressing 102. Similarly, the vent valve 156 may be opened to permit
fluid to flow from the ambient environment into the cartridge 112,
decreasing the negative-pressure in the pressure chamber 126.
[0080] In some embodiments, the pressure-relief valve 160 may be
used to clear blockages in the pressure sensing conduit 140. In
some embodiments, vent valve 156 may be used by the controller 152
to determine if the canister 113 is full. In some embodiments, the
controller 152 may vent the canister 113 through the vent valve 156
and measure a rate of change of negative pressure. If the negative
pressure in the canister 113 changes below a predetermined
threshold rate of change of negative pressure, then the canister
113 may be empty. If the negative pressure in the canister 113
changes above a predetermined threshold rate of change of negative
pressure, then the canister 113 may be full.
[0081] In some embodiments, the therapy system 100 may be operated
in an instillation therapy mode. In the instillation therapy mode,
the controller 152 may position the selector valve 148 in the
second position so that the pump inlet 145 is in fluid
communication with the vent 150. In the second position, the pump
outlet 147 is in fluid communication with the pump therapy port
162. The controller 152 may operate the pump 146 to draw fluid
through the vent 150 and move fluid out of the therapy port 162.
Fluid may be moved into the therapy conduit 142. The valve 144 may
be closed to prevent fluid flow from the first end 141 of the
therapy conduit 142 to the second end 143 of the therapy conduit
142. In this manner, the pump 146 may generate a positive pressure
in the therapy conduit 142 that may be communicated to the pressure
inlet 122. The pump pressure sensor 154 and the therapy-pressure
sensor 158 may determine the pressure in the therapy conduit 142
and the pressure-sensing conduit 140, respectively, and communicate
the pressures to the controller 152. In response, the controller
152 may adjust operation of the therapy system 100 to provide a
predetermined instillation therapy.
[0082] As shown in FIG. 4, the fluid movement into the pressure
inlet 122 may generate a positive pressure in the pressure chamber
126. The positive pressure may cause a pressure differential across
the diaphragm 124, urging the diaphragm 124 toward the fluid inlet
116, the fluid outlet 120, and the discharge position. In some
embodiments, the valve 134 may be closed, and the valve 132 may be
opened, allowing fluid to flow from the dosing chamber 128 through
the fluid outlet 120. Generally, the positive pressure generated by
the pressure source 104 may apply a force to the diaphragm 124 that
moves the diaphragm 124 to the fluid inlet 116, compressing the
dosing chamber 128. In response, the spring 130 may be loaded and
exert a reactive force on the diaphragm 124. Generally, the
positive pressure generated in the pressure chamber 126 may
overcome the reactive force of the spring 130, compressing the
spring 130 as shown in FIG. 4.
[0083] If the diaphragm 124 reaches the discharge position
illustrated in FIG. 4, the controller 152 may stop the operation of
the pump 146. For example, the controller 152 may determine that
the pressure calculated by the pump pressure sensor 154 may be
stable, that is neither increasing nor decreasing beyond a
predetermined range. In response, the controller 152 may open the
vent valve 156 to the ambient environment, allowing the pressure in
the pressure chamber 126 to equalize with the pressure in the
ambient environment. In response, the reactive force generated by
the compression of the spring 130 may act on the diaphragm 124,
urging the diaphragm 124 toward the pressure inlet 122 as the
pressure in the pressure chamber 126 approaches the ambient
pressure. The movement of the diaphragm 124 toward the pressure
inlet 122 may expand the dosing chamber 128, generating a negative
pressure in the dosing chamber 128. The valve 132 may be closed,
and the valve 134 may be opened, so that the negative pressure in
the dosing chamber 128 may draw fluid from the fluid source 118
through the fluid inlet 116 and into the dosing chamber 128,
refilling the dosing chamber 128. If the diaphragm 124 reaches the
charge position of FIG. 2, the controller 152 may close the vent
valve 156. For example, the controller 152 may determine that the
pressure calculated by the pump pressure sensor 154 may be stable,
that is neither increasing nor decreasing beyond a predetermined
range. The controller 152 may operate the pump 146 to again move
fluid into the pressure chamber 126 and provide another
instillation dose to the dressing 102.
[0084] In some embodiments, the dosing chamber 128 may be sized to
hold a predetermined dose of instillation fluid for instillation of
a tissue site. For example, if the diaphragm 124 is in the charge
position illustrated in FIG. 2, the dosing chamber 128 may have a
volume substantially equal to the amount of fluid necessary to
provide a therapeutic dose of instillation fluid to a tissue site.
A therapeutic dose of instillation fluid may be a volume of fluid
required to be delivered to a tissue site to provide suitable
therapeutic benefits to the tissue site. In other embodiments, the
volume of the dosing chamber 128 may be larger or smaller than the
therapeutic dose of instillation fluid.
[0085] In some embodiments, the cartridge 112 may not include the
spring 130. In some embodiments without the spring 130, movement of
the diaphragm 124 may be accomplished by operating the selector
valve 148 to switch from drawing fluid to generate a negative
pressure that moves the diaphragm 124 to the charge position. If
the diaphragm 124 reaches the charge position, the selector valve
148 may be operated to move fluid into the pressure chamber 126,
generating a positive pressure in the pressure chamber 126 and
moving the diaphragm 124 to the discharge position to provide the
instillation dose.
[0086] FIG. 5 is a schematic diagram, illustrating additional
details of a coupling system for the therapy system 100. In some
embodiments, the pressure source 104, the cartridge 112, and the
canister 113 may be coupled directly to one another so that the
pressure source 104, the cartridge 112, and the canister 113 may be
manipulated as a single body. In some embodiments, the direct
coupling may be accomplished by way of a latching system. For
example, the pressure source 104 may include a tang 200 extending
from the pressure source 104. The tang 200 may have a generally
wedge shape having a narrower end distal from the pressure source
104 and a broader end proximate to the pressure sourced 104. In
some embodiments, the tang 200 may include a notch 202 proximate to
the distal end. The notch 202 may be disposed across a surface of
the tang 200. In some embodiments, the tang 200 may increase in
cross-sectional width from the notch 202 to the proximate end of
the tang 200.
[0087] In some embodiments, the cartridge 112 may include release
lever 204. The release lever 204 may include a notch 205 that may
be positioned on the release lever 204 to mate with the notch 202.
In some embodiments, the release lever 204 may include a handle 207
extending from the notch 205. The handle 207 may extend from the
notch 205 outwardly from the cartridge 112. In some embodiments,
the cartridge 112 may also include a tang 206 extending from the
cartridge 112. The tang 206 may have a generally wedge shape having
a narrower end distal from the cartridge 112 and a broader end
proximate to the cartridge 112. In some embodiments, the tang 206
may include a notch 208 proximate to the distal end. The notch 208
may be disposed across a surface of the tang 206. In some
embodiments, the tang 206 may increase in cross-sectional width
from the notch 208 to the proximate end of the tang 206.
[0088] In some embodiments, the canister 113 may include release
lever 210. The release lever 210 may include a notch 209 that may
be positioned on the release lever 210 to mate with the notch 208.
In some embodiments, the release lever 210 may include a handle 212
extending from the notch 209. The handle 212 may extend from the
notch 209 outwardly from the canister 113.
[0089] In some embodiments, the cartridge 112 may be coupled to the
pressure source 104 by placing the cartridge 112 proximate to the
pressure source 104 so that the notch 202 and the notch 205 may
engage each other. In some embodiments, the notch 202 and the notch
205 may have facing surfaces that contact one another to prevent
the cartridge 112 from slipping relative to the pressure source
104. To release the cartridge 112 from the pressure source 104, the
handle 207 may be moved away from the tang 200, disengaging the
notch 205 from the notch 202. In a similar manner, the canister 113
may be coupled to and released from the cartridge 112. In some
embodiments, the cartridge 112 may not be used and the canister 113
may be coupled directly to the pressure source 104.
[0090] In other embodiments, a pressure source may use other
mechanisms to secure a canister to the pressure source. A cartridge
may be configured to engage both the male and female components of
other mechanisms so that the cartridge may be coupled to a wide
range of pressure sources. For example, an ActiVAC system produced
by Kinetic Concepts, Inc. may have a proprietary latching mechanism
to secure a canister to a pressure source. A cartridge could be
manufactured to engage the proprietary system so that the cartridge
may be directly coupled to both the pressure source and the
canister as generally described above.
[0091] Example embodiments of the cartridge have been described
herein that can be combined with a negative-pressure wound
treatment therapy system to provide controlled instillation
therapy. The cartridge can also be calibrated to provide a dosage
of fluid at a pressure suitable for use with a tissue site, for
example, approximately 100 mm Hg. The cartridge can also be
calibrated to provide an accurate dosing of a prescribed amount of
fluids, for example a 5 milliliter dosage of fluid. The therapy
system described herein may also be used to provide both
negative-pressure therapy and instillation therapy. The therapy
system also provides a disposable cartridge for the provision of
instillation therapy with a single pressure source without
requiring changeover of equipment to switch between
negative-pressure therapy and instillation therapy.
[0092] 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.
[0093] 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.
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