WO2021084444A1

WO2021084444A1 - Flexible fluid storage pouch with absorbent

Info

Publication number: WO2021084444A1
Application number: PCT/IB2020/060109
Authority: WO
Inventors: Matthew Francis Ii Cavanaugh; Justin Rice; Roy Dory; Bradley JONIETZ; Kevin Higley
Original assignee: Kci Licensing, Inc.
Priority date: 2019-11-01
Filing date: 2020-10-28
Publication date: 2021-05-06

Abstract

A soft-sided or flexible storage pouch may be used with a negative-pressure therapy system to receive and store fluids and exudate from a tissue site. The flexible storage pouch may include an envelope formed from one or more polymer films. A serpentine manifold and absorbent layers disposed between layers of the serpentine manifold may be inside the envelope. The pouch may have an inlet fluidly coupled to a tissue site and an outlet fluidly coupled to a negative-pressure source. The serpentine manifold may provide a tortuous fluid path from the inlet to the outlet that can increase or maximize fluid absorption by the absorbent layers. In some embodiments, one or more exudate barriers, such as baffles, may be included. The baffles may be disposed between the layers of the serpentine manifold and may aid in directing the flow of fluid along the tortuous fluid path of the manifold.

Description

FLEXIBLE FLUID STORAGE POUCH WITH ABSORBENT

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of priority to U.S. Provisional Application No. 62/929,378, filed on November 1, 2019, which is incorporated herein by reference in its entirety.

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 storage containers for use with tissue treatment systems.

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] There is also widespread acceptance that cleansing a tissue site can be highly beneficial for new tissue growth. For example, a wound or a cavity can be washed out with a liquid solution for therapeutic purposes. These practices are commonly referred to as "irrigation" and "lavage" respectively. "Instillation" is another practice that generally refers to a process of slowly introducing fluid to a tissue site and leaving the fluid for a prescribed period of time before removing the fluid. For example, instillation of topical treatment solutions over a wound bed can be combined with negative- pressure therapy to further promote wound healing by loosening soluble contaminants in a wound bed and removing infectious material. As a result, soluble bacterial burden can be decreased, contaminants removed, and the wound cleansed.

[0005] While the clinical benefits of negative-pressure therapy and/or instillation therapy are widely known, improvements to therapy systems, components, and processes may benefit healthcare providers and patients. BRIEF SUMMARY

[0006] New and useful systems, apparatuses, and methods for treating tissue 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.

[0007] For example, in some embodiments, a soft-sided or flexible storage pouch may be used with a negative-pressure therapy system to receive and store fluids and exudate from a tissue site. The flexible storage pouch may include an envelope formed from one or more polymer films. One or more fluid storage elements, such as absorbent layers, and a fluid distributor, such as a serpentine manifold, may be disposed inside the envelope. The absorbent layers may be disposed between layers of the serpentine manifold. The envelope may have an inlet and an outlet. The inlet may be fluidly coupled to a tissue site and the outlet may be fluidly coupled to a negative-pressure source. The serpentine manifold may provide a tortuous fluid path from the inlet to the outlet that can increase or maximize fluid absorption by the absorbent layers. In some embodiments, one or more exudate barriers, such as baffles, may be included. The baffles may be disposed between the layers of the serpentine manifold and may aid in directing the flow of fluid along the tortuous fluid path of the manifold. In some embodiments, one or more wicking layers may also be disposed proximate to the absorbent layers and may aid in liquid fluid transmission from the manifold to the absorbent layers. A fdter, such as a hydrophobic fdter may be disposed at the outlet. The hydrophobic fdter may allow the flow of gaseous fluid but prevent the flow of liquid fluid through the fdter and to the negative -pressure source.

[0008] In some embodiments, the manifold may be a felted foam that can provide a low- pressure loss path between the inlet and the outlet. In some embodiments, the path of the manifold may travel between each fluid storage element. In other embodiments, the path of the manifold may travel through groups of fluid storage elements. In yet other embodiments, the path of the manifold may travel around the outside of the fluid storage elements. In yet other embodiments, the manifold may be in any combination of paths within the envelope.

[0009] More generally, a fluid storage pouch may include an envelope defining an interior space, an inlet in the envelope, the inlet fluidly coupled to the interior space, an outlet in the envelope, the outlet fluidly coupled to the interior space, and a manifold in the interior space. The manifold may include a first layer having a first length, and a second layer having a second length. The second layer may be fluidly coupled to the first layer. The fluid storage pouch may further include an absorbent layer between the first layer and the second layer of the manifold.

[0010] In some embodiments, a fluid storage pouch may include a flexible envelope defining an interior space, an inlet in the flexible envelope, the inlet fluidly coupled to the interior space, an outlet in the flexible envelope, the outlet fluidly coupled to the interior space, a manifold in the interior space, the manifold having a serpentine shape and configured to provide a fluid path between the inlet and the outlet, and an absorbent proximate to the manifold. [0011] In other embodiments, a fluid storage pouch may include a first layer and a second layer. The first layer may have a first periphery and the second layer may have a second periphery coupled to the first periphery forming an interior space. The fluid storage pouch may further include a first port in the first layer fluidly coupled to the interior space and a second port in the second layer fluidly coupled to the interior space . A serpentine fluid distributor may be disposed in the interior space . The serpentine fluid distributor may include a plurality of fluid distributor layers and a plurality of gaps between the fluid distributor layers. The plurality of fluid distributor layers may be fluidly coupled to one another. The fluid storage pouch may further include a plurality of fluid storage layers, wherein one fluid storage layer of the plurality of fluid storage layers may be disposed in each gap.

[0012] In yet other embodiments, a fluid storage pouch may include a flexible envelope defining an interior space, an inlet fluidly coupled to the interior space, an outlet fluidly coupled to the interior space, and one or more stacks disposed in the interior space. Each stack may include a manifold layer, and an absorbent layer.

[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] Figure 1 is a block diagram of an example embodiment of a therapy system that can provide negative-pressure treatment and instillation treatment in accordance with this specification;

[0015] Figure 2 is a schematic view, illustrating additional details of an example embodiment of the therapy system of Figure 1 ;

[0016] Figure 3 is an exploded isometric view of an example embodiment of a pouch that can be associated with some embodiments of the therapy system of Figure 1 ;

[0017] Figure 4 is a plan view of another example embodiment of a pouch that can be associated with some embodiments of the therapy system of Figure 1;

[0018] Figure 5 is a cross-sectional view of the pouch of Figure 4 taken along line 5-5;

[0019] Figure 6 is a cross-sectional view of another example embodiment of a pouch that can be associated with some embodiments of the therapy system of Figure 1 ;

[0020] Figure 7 is a cross-sectional view of another example embodiment of a pouch that can be associated with some embodiments of the therapy system of Figure 1 ;

[0021] Figure 8 is a cross-sectional view of another example embodiment of a pouch that can be associated with some embodiments of the therapy system of Figure 1 ;

[0022] Figure 9 is a plan view of another example embodiment of a pouch that can be associated with some embodiments of the therapy system of Figure 1;

[0023] Figure 10 is a cross-sectional view of the pouch of Figure 9 taken along line 10-10; [0024] Figure 11 is a plan view of another example embodiment of a pouch that can be associated with some embodiments of the therapy system of Figure 1;

[0025] Figure 12 is a cross-sectional view of the pouch of Figure 10 taken along line 12-12;

[0026] Figure 13 is a cross-sectional view of another example embodiment of a pouch that can be associated with some embodiments of the therapy system of Figure 1 ;

[0027] Figure 14 is a chart that illustrates how the population of absorbent layers in a pouch can affect the fluid storage capacity of the pouch; and

[0028] Figure 15A, Figure 15B, and Figure 15C are views of an example embodiment of a pouch in different orientations.

DESCRIPTION OF EXAMPLE EMBODIMENTS

[0029] 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 it may omit certain details already well-known in the art. The following detailed description is, therefore, to be taken as illustrative and not limiting.

[0030] 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.

[0031] Figure 1 is a simplified functional block diagram of an example embodiment of a therapy system 100 that can provide negative -pressure therapy with instillation of topical treatment solutions to a tissue site in accordance with this specification.

[0032] 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 bums, 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.

[0033] The therapy system 100 may include a source or supply of negative pressure, such as a negative-pressure source 105, and one or more distribution components. A distribution component is preferably detachable and may be disposable, reusable, or recyclable. A dressing, such as a dressing 110, and a fluid container, such as a pouch 115, are examples of distribution components that may be associated with some examples of the therapy system 100. As illustrated in the example of Figure 1, the dressing 110 may comprise or consist essentially of a tissue interface 120, a cover 125, or both in some embodiments.

[0034] A fluid conductor is another illustrative example of a distribution component. A “fluid conductor,” in this context, broadly includes a tube, pipe, hose, conduit, or other structure with one or more lumina or open pathways 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. Moreover, some fluid conductors may be molded into or otherwise integrally combined with other components. Distribution components may also include or comprise interfaces or fluid ports to facilitate coupling and de-coupling other components. In some embodiments, for example, a dressing interface may facilitate coupling a fluid conductor to the dressing 110. For example, such a dressing interface may be a SENSAT.R.A.C.™ Pad available from Kinetic Concepts, Inc. of San Antonio, Texas.

[0035] The therapy system 100 may also include a regulator or controller, such as a controller 130. Additionally, the therapy system 100 may include sensors to measure operating parameters and provide feedback signals to the controller 130 indicative of the operating parameters. As illustrated in Figure 1, for example, the therapy system 100 may include a first sensor 135 and a second sensor 140 coupled to the controller 130.

[0036] The therapy system 100 may also include a source of instillation solution. For example, a solution source 145 may be fluidly coupled to the dressing 110, as illustrated in the example embodiment of Figure 1. The solution source 145 may be fluidly coupled to a positive-pressure source, such as a positive-pressure source 150, a negative-pressure source such as the negative-pressure source 105, or both in some embodiments. A regulator, such as an instillation regulator 155, may also be fluidly coupled to the solution source 145 and the dressing 110 to ensure proper dosage of instillation solution (e.g. saline) to a tissue site. For example, the instillation regulator 155 may comprise a piston that can be pneumatically actuated by the negative-pressure source 105 to draw instillation solution from the solution source during a negative-pressure interval and to instill the solution to a dressing during a venting interval. Additionally or alternatively, the controller 130 may be coupled to the negative-pressure source 105, the positive-pressure source 150, or both, to control dosage of instillation solution to a tissue site. In some embodiments, the instillation regulator 155 may also be fluidly coupled to the negative-pressure source 105 through the dressing 110, as illustrated in the example of Figure 1.

[0037] Some components of the therapy system 100 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 105 may be combined with the controller 130, the solution source 145, and other components into a therapy unit. [0038] In general, components of the therapy system 100 may be coupled directly or indirectly. For example, the negative-pressure source 105 may be directly coupled to the pouch 115 and may be indirectly coupled to the dressing 110 through the pouch 115. Coupling may include fluid, mechanical, thermal, electrical, or chemical coupling (such as a chemical bond), or some combination of coupling in some contexts. For example, the negative-pressure source 105 may be electrically coupled to the controller 130 and may be fluidly coupled to one or more distribution components to provide a fluid path to a tissue site. 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.

[0039] A negative-pressure supply, such as the negative-pressure source 105, may be a reservoir of air at a negative pressure or may be a manual or electrically-powered device, such as a vacuum pump, a suction pump, a wall suction port available at many healthcare facilities, or a micro pump, for example. “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. 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. 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 provided by the negative-pressure source 105 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 -50 mm Hg (-6.7 kPa) and -300 mm Hg (-39.9 kPa).

[0040] The pouch 115 is representative of a container, canister, or other storage component, which can be used to manage exudates and other fluids withdrawn from a tissue site.

[0041] A controller, such as the controller 130, may be a microprocessor or computer programmed to operate one or more components of the therapy system 100, such as the negative- pressure source 105. In some embodiments, for example, the controller 130 may be a microcontroller, which generally comprises an integrated circuit containing a processor core and a memory programmed to directly or indirectly control one or more operating parameters of the therapy system 100. Operating parameters may include the power applied to the negative-pressure source 105, the pressure generated by the negative-pressure source 105, or the pressure distributed to the tissue interface 120, for example. The controller 130 is also preferably configured to receive one or more input signals, such as a feedback signal, and programmed to modify one or more operating parameters based on the input signals.

[0042] Sensors, such as the first sensor 135 and the second sensor 140, are generally known in the art as any apparatus operable to detect or measure a physical phenomenon or property, and generally provide a signal indicative of the phenomenon or property that is detected or measured. For example, the first sensor 135 and the second sensor 140 may be configured to measure one or more operating parameters of the therapy system 100. In some embodiments, the first sensor 135 may be a transducer configured to measure pressure in a pneumatic pathway and convert the measurement to a signal indicative of the pressure measured. In some embodiments, for example, the first sensor 135 may be a piezo-resistive strain gauge. The second sensor 140 may optionally measure operating parameters of the negative-pressure source 105, such as a voltage or current, in some embodiments. Preferably, the signals from the first sensor 135 and the second sensor 140 are suitable as an input signal to the controller 130, but some signal conditioning may be appropriate in some embodiments. For example, the signal may need to be filtered or amplified before it can be processed by the controller 130. Typically, the signal is an electrical signal, but may be represented in other forms, such as an optical signal.

[0043] The tissue interface 120 can be generally adapted to partially or fully contact a tissue site. The tissue interface 120 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 120 may be adapted to the contours of deep and irregular shaped tissue sites. Any or all of the surfaces of the tissue interface 120 may have an uneven, coarse, or jagged profile.

[0044] In some embodiments, the tissue interface 120 may comprise or consist essentially of a manifold. A manifold in this context may comprise or consist essentially of a means for collecting or distributing fluid across the tissue interface 120 under pressure. For example, a manifold may be adapted to receive negative pressure from a source and distribute negative pressure through multiple apertures across the tissue interface 120, 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, such as fluid from a source of instillation solution, across a tissue site.

[0045] In some illustrative embodiments, a manifold may comprise a plurality of pathways, which can be interconnected to improve distribution or collection of fluids. In some illustrative embodiments, a manifold may comprise or consist essentially of a porous material having interconnected fluid pathways. Examples of suitable porous material that can be adapted to form interconnected fluid pathways (e.g., channels) may include cellular foam, including open-cell foam such as reticulated foam; porous tissue collections; and other porous material such as gauze or felted mat that generally include pores, edges, and/or walls. 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.

[0046] In some embodiments, the tissue interface 120 may comprise or consist essentially of reticulated foam having pore sizes and free volume that may vary according to needs of a prescribed therapy. For example, reticulated foam having a free volume of at least 90% may be suitable for many therapy applications, and foam having an average pore size in a range of 400-600 microns (40-50 pores per inch) may be particularly suitable for some types of therapy. The tensile strength of the tissue interface 120 may also vary according to needs of a prescribed therapy. For example, the tensile strength of foam may be increased for instillation of topical treatment solutions. The 25% compression load deflection of the tissue interface 120 may be at least 0.35 pounds per square inch, and the 65% compression load deflection may be at least 0.43 pounds per square inch. In some embodiments, the tensile strength of the tissue interface 120 may be at least 10 pounds per square inch. The tissue interface 120 may have a tear strength of at least 2.5 pounds per inch. In some embodiments, the tissue interface may be foam comprised of polyols such as polyester or polyether, isocyanate such as toluene diisocyanate, and polymerization modifiers such as amines and tin compounds. In some examples, the tissue interface 120 may be reticulated polyurethane foam such as found in GRANUFOAM™ Dressing or V.A.C. VERAFLO™ Dressing, both available from Kinetic Concepts, Inc. of San Antonio, Texas.

[0047] The thickness of the tissue interface 120 may also vary according to needs of a prescribed therapy. For example, the thickness of the tissue interface may be decreased to reduce tension on peripheral tissue. The thickness of the tissue interface 120 can also affect the conformability of the tissue interface 120. In some embodiments, a thickness in a range of about 5 millimeters to 10 millimeters may be suitable.

[0048] The tissue interface 120 may be either hydrophobic or hydrophilic. In an example in which the tissue interface 120 may be hydrophilic, the tissue interface 120 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 120 may draw fluid away from a tissue site by capillary flow or other wicking mechanisms. An example of a hydrophilic material that may be suitable is a polyvinyl alcohol, open-cell foam such as V.A.C. WHITEFOAM™ dressing available from Kinetic Concepts, Inc. of San Antonio, Texas. 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.

[0049] In some embodiments, the tissue interface 120 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 120 may further serve as a scaffold for new cell-growth, or a scaffold material may be used in conjunction with the tissue interface 120 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.

[0050] In some embodiments, the cover 125 may provide a bacterial barrier and protection from physical trauma. The cover 125 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 125 may comprise or consist of, for example, an elastomeric fdm 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 125 may have a high moisture-vapor transmission rate (MVTR) in some applications. For example, the MVTR may be at least 250 grams per square meter per twenty-four hours in some embodiments, measured using an upright cup technique according to ASTM E96/E96M Upright Cup Method at 38°C and 10% relative humidity (RH). In some embodiments, an MVTR up to 5,000 grams per square meter per twenty-four hours may provide effective breathability and mechanical properties.

[0051] In some example embodiments, the cover 125 may be a polymer drape, such as a polyurethane fdm, 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. The cover 125 may comprise, for example, one or more of the following materials: polyurethane (PU), such as hydrophilic polyurethane; cellulosics; hydrophilic polyamides; polyvinyl alcohol; polyvinyl pyrrolidone; hydrophilic acrylics; silicones, such as hydrophilic silicone elastomers; natural rubbers; polyisoprene; styrene butadiene rubber; chloroprene rubber; polybutadiene; nitrile rubber; butyl rubber; ethylene propylene rubber; ethylene propylene diene monomer; chlorosulfonated polyethylene; polysulfide rubber; ethylene vinyl acetate (EVA); co-polyester; and polyether block polymide copolymers. Such materials are commercially available as, for example, Tegaderm® drape, commercially available from 3M Company, Minneapolis Minnesota; polyurethane (PU) drape, commercially available from Avery Dennison Corporation, Pasadena, California; polyether block polyamide copolymer (PEBAX), for example, from Arkema S.A., Colombes, France; and Inspire 2301 and Inpsire 2327 polyurethane fdms, commercially available from Expopack Advanced Coatings, Wrexham, United Kingdom. In some embodiments, the cover 125 may comprise INSPIRE 2301 having an MVTR (upright cup technique) of 2600 g/m²/24 hours and a thickness of about 30 microns.

[0052] An attachment device may be used to attach the cover 125 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 configured to bond the cover 125 to epidermis around a tissue site. In some embodiments, for example, some or all of the cover 125 may be coated with an adhesive, such as an acrylic adhesive, which may have a coating weight of about 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.

[0053] The solution source 145 may also be representative of a container, canister, pouch, bag, or other storage component, which can provide a solution for instillation therapy. Compositions of solutions may vary according to a prescribed therapy, but examples of solutions that may be suitable for some prescriptions include hypochlorite-based solutions, silver nitrate (0.5%), sulfur-based solutions, biguanides, cationic solutions, and isotonic solutions.

[0054] In operation, the tissue interface 120 may be placed within, over, on, or otherwise proximate to a tissue site. If the tissue site is a wound, for example, the tissue interface 120 may partially or completely fill the wound, or it may be placed over the wound. The cover 125 may be placed over the tissue interface 120 and sealed to an attachment surface near a tissue site. For example, the cover 125 may be sealed to undamaged epidermis peripheral to a tissue site. Thus, the dressing 110 can provide a sealed therapeutic environment proximate to a tissue site, substantially isolated from the external environment, and the negative-pressure source 105 can reduce pressure in the sealed therapeutic environment.

[0055] 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 and instillation 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.

[0056] In general, exudate and other fluid 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.

[0057] Negative pressure applied across the tissue site through the tissue interface 120 in the sealed therapeutic environment can induce macro-strain and micro-strain in the tissue site. Negative pressure can also remove exudate and other fluid from a tissue site, which can be collected in the pouch 115.

[0058] In some embodiments, the controller 130 may receive and process data from one or more sensors, such as the first sensor 135. The controller 130 may also control the operation of one or more components of the therapy system 100 to manage the pressure delivered to the tissue interface 120. In some embodiments, controller 130 may include an input for receiving a desired target pressure and may be programmed for processing data relating to the setting and inputting of the target pressure to be applied to the tissue interface 120. In some example embodiments, the target pressure may be a fixed pressure value set by an operator as the target negative pressure desired for therapy at a tissue site and then provided as input to the controller 130. The target pressure may vary from tissue site to tissue site based on the type of tissue forming a tissue site, the type of injury or wound (if any), the medical condition of the patient, and the preference of the attending physician. After selecting a desired target pressure, the controller 130 can operate the negative -pressure source 105 in one or more control modes based on the target pressure and may receive feedback from one or more sensors to maintain the target pressure at the tissue interface 120.

[0059] In some embodiments, the controller 130 may have a continuous pressure mode, in which the negative-pressure source 105 is operated to provide a constant target negative pressure for the duration of treatment or until manually deactivated. Additionally or alternatively, the controller may have an intermittent pressure mode. For example, the controller 130 can operate the negative- pressure source 105 to cycle between a target pressure and atmospheric pressure. For example, the target pressure may be set at a value of 135 mmHg for a specified period of time (e.g., 5 min), followed by a specified period of time (e.g., 2 min) of deactivation. The cycle can be repeated by activating the negative-pressure source 105, which can form a square wave pattern between the target pressure and atmospheric pressure.

[0060] In some example embodiments, the increase in negative-pressure from ambient pressure to the target pressure may not be instantaneous. For example, the negative-pressure source 105 and the dressing 110 may have an initial rise time. The initial rise time may vary depending on the type of dressing and therapy equipment being used. For example, some therapy systems may increase negative pressure at a rate of about 20-30 mmHg/second, and other therapy systems may increase negative pressure at a rate of about 5-10 mmHg/second. If the therapy system 100 is operating in an intermittent mode, the repeating rise time may be a value substantially equal to the initial rise time.

[0061] In some example dynamic pressure control modes, the target pressure can vary with time. For example, the target pressure may vary in the form of a triangular waveform, varying between a negative pressure of 50 and 135 mmHg with a rise rate of negative pressure set at a rate of 25 mmHg/min. and a descent rate set at 25 mmHg/min. In other embodiments of the therapy system 100, the triangular waveform may vary between negative pressure of 25 and 135 mmHg with a rise rate of about 30 mmHg/min. and a descent rate set at about 30 mmHg/min.

[0062] In some embodiments, the controller 130 may control or determine a variable target pressure in a dynamic pressure mode, and the variable target pressure may vary between a maximum and minimum pressure value that may be set as an input prescribed by an operator as the range of desired negative pressure. The variable target pressure may also be processed and controlled by the controller 130, which can vary the target pressure according to a predetermined waveform, such as a triangular waveform, a sine waveform, or a saw-tooth waveform. In some embodiments, the waveform may be set by an operator as the predetermined or time-varying negative pressure desired for therapy.

[0063] In some embodiments, the controller 130 may receive and process data, such as data related to instillation solution provided to the tissue interface 120. Such data may include the type of instillation solution prescribed by a clinician, the volume of fluid or solution to be instilled to a tissue site (“fill volume”), and the amount of time prescribed for leaving solution at a tissue site (“dwell time”) before applying a negative pressure to the tissue site. The fill volume may be, for example, between 10 and 500 mL, and the dwell time may be between one second to 30 minutes. The controller 130 may also control the operation of one or more components of the therapy system 100 to instill solution. For example, the controller 130 may manage fluid distributed from the solution source 145 to the tissue interface 120. In some embodiments, fluid may be instilled to a tissue site by applying a negative pressure from the negative-pressure source 105 to reduce the pressure at the tissue site, drawing solution into the tissue interface 120. In some embodiments, solution may be instilled to a tissue site by applying a positive pressure from the positive-pressure source 150 to move solution from the solution source 145 to the tissue interface 120. Additionally or alternatively, the solution source 145 may be elevated to a height sufficient to allow gravity to move solution into the tissue interface 120.

[0064] The controller 130 may also control the fluid dynamics of instillation by providing a continuous flow of solution or an intermittent flow of solution. Negative pressure may be applied to provide either continuous flow or intermittent flow of solution. The application of negative pressure may be implemented to provide a continuous pressure mode of operation to achieve a continuous flow rate of instillation solution through the tissue interface 120, or it may be implemented to provide a dynamic pressure mode of operation to vary the flow rate of instillation solution through the tissue interface 120. Alternatively, the application of negative pressure may be implemented to provide an intermittent mode of operation to allow instillation solution to dwell at the tissue interface 120. In an intermittent mode, a specific fill volume and dwell time may be provided depending, for example, on the type of tissue site being treated and the type of dressing being utilized. After or during instillation of solution, negative-pressure treatment may be applied. The controller 130 may be utilized to select a mode of operation and the duration of the negative pressure treatment before commencing another instillation cycle.

[0065] Figure 2 is a schematic view, illustrating details of an example embodiment of the therapy system 100. The therapy system 100 is shown applied to a human patient 200, but the therapy system 100 may be used on other types of subjects. In some embodiments, the dressing 110 may be fluidly coupled to the pouch 115 with a first fluid conductor 205, and the pouch 115 may be fluidly coupled to the negative-pressure source 105 with a second fluid conductor 210. The negative-pressure source 105 may provide negative pressure through the second fluid conductor 210, the pouch 115, and the first fluid conductor 205 to the dressing 110 to remove fluids from a tissue site. Fluids may be delivered to the pouch 115 for storage and later removal. In other embodiments, the fluids may be from an ostomy bag or another source rather than dressing 110.

[0066] In some embodiments, the pouch 115 may include one or more straps 215 configured to mount pouch 115 to a patient. Similarly, the negative-pressure source 105 may also include one or more straps 220, allowing the negative-pressure source 105 to be mounted to the patient 200. The straps 215 and the straps 220 may be elastomeric members, belt-like members, or the like. In addition, the straps 215 and the straps 220 may be adjustable, permanently secured, or releasably coupled to the pouch 115 and the negative-pressure source 105, respectively. In some embodiments, the straps 215 and the straps 220 may allow positioning of the pouch 115 and the negative-pressure source 105 at different locations on the patient 200 so that the weight of the therapy system 100 may be distributed at more than one location of the patient 200. For example, the pouch 115 may be strapped to a portion of the patient 200, such as a leg 225, using the straps 215 or other attachment devices. Similarly, the negative-pressure source 105 may be mounted to another portion of the patient 200, such as a waist 230, using the straps 220. The pouch 115 may be oriented as shown in Figure 2, or the pouch 115 may be oriented in other positions to improve fit to, and comfort of, the patient 200. In some embodiments, the negative-pressure source 105 and the pouch 115 may also be mounted at locations other than the patient 200, for example, on a bed, pole, or the like. In some embodiments, the pouch 115 may be proximate to the negative-pressure source 105. For example, in some embodiments, the negative- pressure source 105 and the pouch 115 may be placed in a fabric enclosure having a pocket for the negative-pressure source 105 and a pocket for the pouch 115. In some embodiments, the pouch 115 may be strapped to the negative-pressure source 105 or connected to the negative-pressure source 105 using one or more connectors.

[0067] Figure 3 is an exploded isometric view of an example of the pouch 115 that can be associated with some embodiments of the therapy system 100. As shown in Figure 3, the pouch 115 may comprise a first layer 300, a second layer 305, a fluid distributor, such as a serpentine manifold 310, and one or more fluid storage layers, such as one or more absorbent layers 315, between the manifold 310. The manifold 310 and the one or more absorbent layers 315 are configured to be sandwiched between the first layer 300 and the second layer 305.

[0068] In some embodiments, the first layer 300 and the second layer 305 may both be formed from or include a polymer film. In some embodiments, the first layer 300 and the second layer 305 may comprise a thermoplastic film or sheet. The first layer 300 and the second layer 305 may comprise, for example, one or more of the following materials: thermoplastic polyurethane (TPU); polyurethane (PU), such as hydrophilic polyurethane; cellulosics; hydrophilic polyamides; polyvinyl alcohol; polyvinyl pyrrolidone; hydrophilic acrylics; silicones, such as hydrophilic silicone elastomers; natural rubbers; polyisoprene; styrene butadiene rubber; chloroprene rubber; polybutadiene; nitrile rubber; butyl rubber; ethylene propylene rubber; ethylene propylene diene monomer; chlorosulfonated polyethylene; polysulfide rubber; ethylene vinyl acetate (EVA); co-polyester; and polyether block polymide copolymers. In some embodiments, one or more of the first layer 300 and the second layer 305 may be fluid impermeable. For example, one or more of the first layer 300 and the second layer 305 may be configured to prevent the passage of liquid and gas through the first layer 300 and/or the second layer 305. In some embodiments, one or more of the first layer 300 and the second layer 305 may be configured to prevent the passage of liquid, but allow the passage of gas or vapor, through the first layer 300 and/or the second layer 305. In some embodiments, one or more of the first layer 300 and the second layer 305 may be formed of a material that is liquid impermeable. In some embodiments, one or more of the first layer 300 and the second layer 305 may be formed of a material that is gas impermeable. In some embodiments, one or more of the first layer 300 and the second layer 305 may be formed of a material that is liquid impermeable but gas permeable.

[0069] In some embodiments, one or more of the first layer 300 and the second layer 305 may have a high moisture-vapor transmission rate (MVTR) in some applications. For example, the MVTR may be at least 250 grams per square meter per twenty-four hours in some embodiments, measured using an upright cup technique according to ASTM E96/E96M Upright Cup Method at 38°C and 10% relative humidity (RH). In some embodiments, an MVTR up to 5,000 grams per square meter per twenty-four hours may provide effective breathability and mechanical properties. In some example embodiments, one or more of the first layer 300 and the second layer 305 may be a polymer sheet, such as a polyurethane film, that is permeable to water vapor but impermeable to liquid. If one or more of the first layer 300 and the second layer 305 have a high MVTR, some of the fluids captured by the absorbent layers 315 may evaporate and exit the pouch 115 through one or more of the first layer 300 and the second layer 305 as water vapor. This may increase the storage capacity of the pouch 115.

[0070] As illustrated in the example of Figure 3, in some embodiments, one or more of the first layer 300 and the second layer 305 may be generally flat sheets. In some embodiments, one or more of the first layer 300 and the second layer 305 may be formed to have convex shape into which the manifold 300 and the absorbent layers 315 may be inserted. Forming one or more of the first layer 300 and the second layer 305 may increase the volume of the pouch 115.

[0071] As further shown in Figure 3, the first layer 300 may include a first aperture, such as an inlet 320. The inlet 320 may form a first port. A first negative-pressure interface, such as an inlet interface 325, may be placed over the inlet 320 to provide a fluid path between the first fluid conductor 205 and the manifold 310. The second layer 305 may include a second aperture, such as an outlet 330. The outlet 330 may form a second port. A second negative-pressure interface, such as an outlet interface 335, may be placed over the outlet 330 to provide a fluid path between the second fluid conductor 210 and the manifold 310. In some embodiments, a filter 340 may be included between the outlet 330 and the outlet interface 335. The filter 340 may be a hydrophobic filter so that fluid communication into the outlet interface 335 and the second fluid conductor 210 may be limited to communication of negative-pressure, reducing or preventing liquid from flowing into the outlet interface 335 and the second fluid conductor 210.

[0072] As shown in Figure 3, the manifold 310 may have a serpentine shape. The manifold 310 generally comprises one or more manifolds or manifold layers, which can provide a means for collecting or distributing fluid from the inlet 320 to the outlet 330 of the pouch 115 under pressure. For example, the manifold 310 may be adapted to receive negative pressure from a source and distribute negative pressure along the length of the manifold 310, which may have the effect of collecting fluid from a tissue site and drawing the fluid toward the source.

[0073] In some illustrative embodiments, the pathways of the manifold 310 may be interconnected to improve distribution or collection of fluids. In some illustrative embodiments, the manifold 310 may comprise or consist essentially of a porous material having interconnected fluid pathways. Examples of suitable porous material that comprise or can be adapted to form interconnected fluid pathways (e.g., channels) may include cellular foam, including open-cell foam such as reticulated foam; porous tissue collections; and other porous material such as gauze or felted mat that generally include pores, edges, and/or walls. Liquids, gels, and other foams may also include or be cured to include apertures and fluid pathways. In some embodiments, the manifold 310 may additionally or alternatively comprise projections that form interconnected fluid pathways. For example, the manifold 310 may be molded to provide surface projections that define interconnected fluid pathways.

[0074] In some embodiments, the manifold 310 may be formed by a felting process. Any porous foam suitable for felting may be used, including GRANUFOAM™ Dressing or reticulated polyurethane foam such as found in V.A.C. VERAFLO™ Dressing, both available from Kinetic Concepts, Inc. of San Antonio, Texas. Felting comprises a thermoforming process that permanently compresses a foam to increase the density of the foam while maintaining interconnected pathways. Felting may be performed by any known methods, which may include applying heat and pressure to a porous material or foam material. Some methods may include compressing a foam blank between one or more heated platens or dies (not shown) for a specified period of time and at a specified temperature. The direction of compression may be along the thickness of the foam blank.

[0075] The period of time of compression may range from 10 minutes up to 24 hours, though the time period may be more or less depending on the specific type of porous material used. Further, in some examples, the temperature may range between 120°C to 260°C. Generally, the lower the temperature of the platen, the longer a porous material must be held in compression. After the specified time period has elapsed, the pressure and heat will form a felted structure or surface on or through the porous material or a portion of the porous material.

[0076] The felting process may alter certain properties of the original material, including pore shape and/or size, elasticity, density, and density distribution. For example, struts that define pores in the foam may be deformed during the felting process, resulting in flattened pore shapes. The deformed struts can also decrease the elasticity of the foam. The density of the foam is generally increased by felting. In some embodiments, contact with hot-press platens in the felting process can also result in a density gradient in which the density is greater at the surface and the pores size is smaller at the surface. In some embodiments, the felted structure may be comparatively smoother than any unfinished or non- felted surface or portion of the porous material. Further, the pores in the felted structure may be smaller than the pores throughout any unfinished or non-felted surface or portion of the porous material. In some examples, the felted structure may be applied to all surfaces or portions of the porous material. Further, in some examples, the felted structure may extend into or through an entire thickness of the porous material such that the all of the porous material is felted.

[0077] A felted foam may be characterized by a firmness factor, which is indicative of the compression of the foam. The firmness factor of a felted foam can be specified as the ratio of original thickness to final thickness. A compressed or felted foam may have a firmness factor greater than 1. The degree of compression may affect the physical properties of the felted foam. For example, felted foam has an increased effective density compared to a foam of the same material that is not felted. The felting process can also affect fluid-to-foam interactions. For example, as the density increases, compressibility or collapse may decrease. Therefore, foams which have different compressibility or collapse may have different firmness factors. In some example embodiments, a firmness factor can range from about 2 to about 10, preferably about 3 to about 7. For example, the firmness factor of the manifold 310 felted foam may be about 5 in some embodiments. There is a general linear relationship between firmness level, density, pore size (or pores per inch) and compressibility. The physical properties of a felted foam in relation to the physical properties of a pre-felted or unfelted foam from which the felted foam is formed may be determined by one or more of the following equations:

Average Pores per Inch_Feited = Average Pores Per Inch_Unf_eited x Firmness Factor

(Eq. 4);

25% Compression Load Deflection_Feited =

25% Compression Load Deflection_Unf_eited x Firmness Factor (Eq. 5); and

65% Compression Load Deflection_Feited =

65% Compression Load Deflection_Un^_eited x Firmness Factor (Eq. 6).

For example, foam that is felted to a firmness factor of 3 will show a three-fold density increase and compress to about a third of its original thickness. Foam that is felted to a firmness factor of 3 may show a three-fold decrease in pore size, a three-fold decrease in free volume, a three-fold increase in average pores per inch, a three-fold increase in 25% compression load deflection, and a three-fold increase in 65% compression load deflection.

[0078] In some embodiments, a suitable foam blank (e.g. of pre-felted foam) for formation of the manifold 310 may have about 40 to about 50 pores per inch on average, a density of about 1.3 to about 1.6 lb/ft³, a free volume of about 90% or more, an average pore size in a range of about 400 to about 600 microns, a 25% compression load deflection of at least 0.35 pounds per square inch, and/or a 65% compression load deflection of at least 0.43 pounds per square inch. For example, the foam blank may be GRANUFOAM™ Dressing. In some embodiments, a suitable foam blank for formation of the manifold 310 may have about 40 to about 50 pores per inch on average, a density of about 1.7 to about 2.1 lb/ft³, an average pore size in a range of about 400 to about 600 microns, a 25% compression load deflection of at least 0.35 pounds per square inch, and/or a 65% compression load deflection of at least 0.6 pounds per square inch. For example, the foam blank may be foam such as found in V.A.C. VERAFLO™ Dressings. In some embodiments, the foam blank may have a thickness greater than 10 millimeters, for example 10-35 millimeters, 10-25 millimeters, 10-20 millimeters, or 15-20 millimeters. In some embodiments, the foam blank may be felted to provide denser foam for the manifold 310. For example, the foam blank may be felted to a firmness factor of 2-10. In some embodiments, the foam blank may be felted to a firmness factor of 3-7. Some embodiments may felt the foam blank to a firmness factor of 5.

[0079] In some embodiments, the manifold 310 may comprise an open-cell foam having a free volume of about 13% to about 30%, a density of about 3.9 to about 11.2 lb/ft³, about 120 to about 350 pores per inch on average (e.g., as measured in the direction of compression), and/or average pore size of about 57 to about 200 microns (e.g., as measured in the direction of compression), which may be particularly advantageous under negative pressure. For example, the denser foam may better maintain fluid flow when under negative pressure. In some embodiments, the foam of the manifold 310 may have a 25% compression load deflection of about 1.05 to about 2.45 pounds per square inch and a 65% compression load deflection of about 1.29 to about 3.01 pounds per square inch. In some embodiments, the density of the foam of the manifold 310 may be about 3.9 to about 4.8 lb/ft³. In some embodiments, the free volume of the foam may be about 30%. In some embodiments, the average pore size of the manifold 310 may be about 133 to about 200 microns. In some embodiments, the manifold 310 may have about 120 to about 150 pores per inch on average. In some embodiments, the foam of the manifold 310 may have a 25% compression load deflection of at least 1.05 pounds per square inch and a 65% compression load deflection of at least 1.29 pounds per square inch. In some embodiments, the density of the foam of the manifold 310 may be about 6.5 to about 8.0 lb/ft³. In some embodiments, the free volume of the foam may be about 18%. In some embodiments, the average pore size of the manifold 310 may be about 80 to about 120 microns. In some embodiments, the manifold 310 may have about 200 to about 250 pores per inch on average. In some embodiments, the foam of the manifold 310 may have a 25% compression load deflection of at least 1.75 pounds per square inch and a 65% compression load deflection of at least 2.15 pounds per square inch. In some embodiments, the density of the foam of the manifold 310 may be about 9.1 to about 11.2 lb/ft³. In some embodiments, the free volume of the foam may be about 13%. In some embodiments, the average pore size of the manifold 310 may be about 57 to about 86 microns. In some embodiments, the manifold 310 may have about 280 to about 350 pores per inch on average. In some embodiments, the foam of the manifold 310 may have a 25% compression load deflection of at least 2.45 pounds per square inch and a 65% compression load deflection of at least 3.01 pounds per square inch. [0080] In some embodiments, the manifold 310 may comprise an open-cell foam having a density of about 5.1 to about 14.7 lb/ft³, about 120 to about 350 pores per inch on average (e.g., as measured in the direction of compression), and/or average pore size of about 57 to about 200 microns (e.g., as measured in the direction of compression), which may be particularly advantageous under negative pressure. For example, the denser foam may better maintain fluid flow when under negative pressure. In some embodiments, the foam of the manifold 310 may have a 25% compression load deflection of about 1.05 to about 2.45 pounds per square inch and a 65% compression load deflection of about 1.8 to about 4.2 pounds per square inch. In some embodiments, the density of the foam of the manifold 310 may be about 5.1 to about 6.3 lb/ft³. In some embodiments, the average pore size of the manifold 310 may be about 133 to about 200 microns. In some embodiments, the manifold 310 may have about 120 to about 150 pores per inch on average. In some embodiments, the foam of the manifold 310 may have a 25% compression load deflection of at least 1.05 pounds per square inch and a 65% compression load deflection of at least 1.8 pounds per square inch. In some embodiments, the density of the foam of the manifold 310 may be about 8.5 to about 10.5 lb/ft³. In some embodiments, the average pore size of the manifold 310 may be about 80 to about 120 microns. In some embodiments, the manifold 310 may have about 200 to about 250 pores per inch on average. In some embodiments, the foam of the manifold 310 may have a 25% compression load deflection of at least 1.75 pounds per square inch and a 65% compression load deflection of at least 3.0 pounds per square inch. In some embodiments, the density of the foam of the manifold 310 may be about 11.9 to about 14.7 lb/ft³. In some embodiments, the average pore size of the manifold 310 may be about 57 to about 86 microns. In some embodiments, the manifold 310 may have about 280 to about 350 pores per inch on average. In some embodiments, the foam of the manifold 310 may have a 25% compression load deflection of at least 2.45 pounds per square inch and a 65% compression load deflection of at least 4.2 pounds per square inch.

[0081] In some embodiments, the foam forming the manifold 310 may be cut perpendicular to the felting direction to provide pore structures that run parallel to the fluid path created by the manifold 310. Felting may compress the pores in the direction of felting. For example, the pores in the foam forming the manifold 310 may have a first average cross-sectional area perpendicular to the direction of felting and a second average cross-sectional area parallel to the direction of felting, wherein the first average cross-sectional area is less than the second average cross-sectional area. The pores in the foam may be smaller perpendicular to the direction of felting, than parallel to the direction of felting. In some embodiments, the foam forming the manifold 310 may be oriented so that the first average cross- sectional area is perpendicular to the length of the manifold 310 and the second cross-sectional area is parallel to the length of the manifold 310. The larger second average cross-sectional area of the pores may face an absorbent layer 315. The air in the fluid flowing through the manifold 310 may flow through the smaller first average cross-sectional area without a significant pressure drop, while the liquid in the fluid flowing through the manifold 310 may fall through the larger second average cross- sectional area and into the absorbent layers 315. Orienting the length of the manifold 310 perpendicular to the felting direction may assist with reducing pressure drop across the manifold 310, may increase the manifolding of fluid through the manifold 310, and may increase the amount of liquid fluid absorbed by the absorbent layers 315.

[0082] While the various physical properties of the manifold 310 are described as achieved via a felting process, in some embodiments, the physical properties of the manifold 310 may be achieved by other methods.

[0083] The absorbent layers 315 may be disposed between the layers of the manifold 310. The absorbent layers 315 store, or immobilize, the liquid from a tissue site. The absorbent layers 315 may be any substance capable of storing a liquid, such as exudate. For example, the absorbent layers 315 may form a chemical bond with exudate from the tissue site. Non-limiting examples of the absorbent layers 315 include super absorbent fiber/particulates, hydrofibre, sodium carboxymethyl cellulose, and/or alginates. In some exemplary embodiments, the absorbent layers 315 may be formed of a superabsorbent polymer (SAP). Generally, relative to their mass, SAPs can absorb and retain large quantities of liquid, and in particular water. SAPs may be used to hold and stabilize or solidify wound fluids. The SAPs used to form the absorbent layers 315 may be of the type often referred to as “hydrogels,” “super-absorbents,” or “hydrocolloids.” When disposed within the pouch 115, the SAPs may be formed into fibers or spheres to manifold reduced pressure until the SAPs become saturated. Spaces or voids between the fibers or spheres may allow a reduced pressure that is applied to the pouch 115 to be transferred within and through the absorbent layers 315. In some embodiments, fibers of the absorbent layers 315 may be either woven or non-woven. In some embodiments, the absorbent layers 315 may comprise a substrate in which the SAPs may be dispersed as pellets throughout and/or embedded as a sheet-like layer within the substrate.

[0084] The SAPs may be formed in several ways, for example, by gel polymerization, solution polymerization, or suspension polymerization. Gel polymerization may involve blending of acrylic acid, water, cross-linking agents, and ultraviolet (UV) initiator chemicals. The blended mixture may be placed into a reactor where the mixture is exposed to UV light to cause crosslinking reactions that form the SAP. The mixture may be dried and shredded before subsequent packaging and/or distribution. Solution polymerization may involve a water based monomer solution that produces a mass of reactant polymerized gel. The monomer solution may undergo an exothermic reaction that drives the crosslinking of the monomers. Following the crosslinking process, the reactant polymer gel may be chopped, dried, and ground to its final granule size. Suspension polymerization may involve a water- based reactant suspended in a hydrocarbon-based solvent. However, the suspension polymerization process must be tightly controlled and is not often used.

[0085] SAPs absorb liquids by bonding with water molecules through hydrogen bonding. Hydrogen bonding involves the interaction of a polar hydrogen atom with an electronegative atom. As a result, SAPs absorb water based on the ability of the hydrogen atoms in each water molecule to bond with the hydrophilic polymers of the SAP having electronegative ionic components. High absorbing SAPs are formed from ionic crosslinked hydrophilic polymers such as acrylics and acrylamides in the form of salts or free acids. Because the SAPs are ionic, they are affected by the soluble ionic components within the solution being absorbed and will, for example, absorb less saline than pure water. The lower absorption rate of saline is caused by the sodium and chloride ions blocking some of the water absorbing sites on the SAPs. If the fluid being absorbed by the SAP is a solution containing dissolved mineral ions, fewer hydrogen atoms of the water molecules in the solution may be free to bond with the SAP. Thus, the ability of an SAP to absorb and retain a fluid may be dependent upon the ionic concentration of the fluid being absorbed. For example, an SAP may absorb and retain de-ionized water up to 500 times the weight of the dry SAP. In volumetric terms, an SAP may absorb fluid volumes as high as 30 to 60 times the dry volume of the SAP. Other fluids having a higher ionic concentration may be absorbed at lower quantities. For example, an SAP may only absorb and retain a solution that is 0.9% salt (NaCl) up to 50 times the weight of the dry SAP. Since wound fluids contain salts, such as sodium, potassium, and calcium, the absorption capacity of the SAP may be reduced if compared to the absorption capacity of deionized water.

[0086] In some embodiments, the absorbent layers 315 may comprise a KERRAMAX CARE™ Super-Absorbent Dressing material available from Kinetic Concepts, Inc. of San Antonio, Texas. For example, the absorbent layers 315 may comprise a superabsorbent laminate comprised of 304 g.s.m. FAVOR-PAC™ 230 superabsorbent powder glued by PAFRA™ 8667 adhesive between two layers of 50 g.s.m. LIDRO™ non-woven material. In some embodiments, the absorbent layers 315 may comprise an absorbent available from Gelok International. The presence of the absorbent layers 315 may also help to minimize fluid loss or reflux.

[0087] Figure 4 is a plan view of another example embodiment of the pouch 115 that can be associated with some embodiments of the therapy system 100. As shown in Figure 4, the first layer 300 and the second layer 305 may be coupled on peripheral portions of the first layer 300 and the second layer 305 to form an envelope 400 having an interior space 405 containing the manifold 310 and the one or more absorbent layers 315. The interior space 405 of the pouch 115 may be a single chamber containing the manifold 310 and the one or more absorbent layers 315. The manifold 310 and the exudate and/or other liquids stored in the pouch 115 may be in the same single chamber. The first layer 300 and the second layer 305 may be adhered together in some embodiments. Suitable bonds between the first layer 300 and the second layer 305 may include pressure-sensitive adhesive (reactive and non reactive types); hot melt adhesive (spray applied or deployed as a film, woven, or non-woven); hot press lamination; or flame lamination. In some embodiments, the first layer 300 and the second layer 305 may be welded together. For example, the first layer 300 may be and the second layer 305 may be welded together using heat, radio frequency (RF) welding, or other methods to generate heat such as ultrasonic welding. RF welding may be particularly suitable for more polar materials, such as polyurethane, polyamides, polyesters and acrylates. Sacrificial polar interfaces may be used to facilitate RF welding of less polar film materials, such as polyethylene. In some embodiments, a weld 410 may extend around the peripheral portions of the first layer 300 and the second layer 305, sealing the pouch 115 and forming an inner boundary line 415. In some embodiments, the envelope 400 may be fluid impermeable. For example, envelope 400 may be configured to prevent the passage of liquid and gas through the envelope 400. In some embodiments, the envelope 400 may be configured to prevent the passage of liquid, but allow the passage of gas or vapor, from inside the interior space 405 through the envelope 400 to the environment outside the pouch 115. In some embodiments, the envelope 400 may be formed of a material that is liquid impermeable. In some embodiments, the envelope 400 may be formed of a material that is gas impermeable. In some embodiments, the envelope 400 may be formed of a material that is liquid impermeable but gas permeable.

[0088] The pouch 115 may have a length 416 and a width 417 along the inner boundary line 415. In some embodiments, the length 416 may be in a range of about 5 centimeters to about 20 centimeters and the width 417 may be in a range of about 5 centimeters to about 20 centimeters. In some embodiments, the length 416 may be about 11 centimeters and the width 417 may be about 8.5 centimeters. The length 416 and the width 417 along the inner boundary line 415 may define a first planar area A_/. In some embodiments, the first planar area A _/ may be in a range of about 50 cm² to about 150 cm². In some embodiments, the first planar area A _/ may be in a range of about 75 cm² to about 100 cm². In some embodiments, the first planar area A may be about 93.5 cm². The dimensions of the pouch 115 may vary according to a prescribed therapy or application. With the expansion properties of the absorbent layers 315 during liquid fluid absorption, the dimensions of the pouch 115 may determine the liquid volume capacity of the pouch 115.

[0089] The one or more absorbent layers 315 may have a length 418 and a width 419. In some embodiments, the length 418 of the absorbent layers 315 may be less than or equal to the length 416 of the pouch 115. In some embodiments, the length 418 of the absorbent layers 315 may be equal to the length 416 of the pouch 115 minus a thickness of the manifold 310. In some embodiments, the width 419 of the absorbent layers 315 may be less than or equal to the width 417 of the pouch 115. In some embodiments, the width 419 of the absorbent layers 315 may be about equal to the width 417 of the pouch 115. In some embodiments, the length 418 may be in a range of about 5 centimeters to about 20 centimeters and the width 419 may be in a range of about 5 centimeters to about 20 centimeters. In some embodiments, the length 418 may be about 9 centimeters and the width 419 may be about 7 centimeters. In some embodiments, the length 418 may be about 8.5 centimeters and the width 419 may be about 8.5 centimeters. The one or more absorbent layers 315 may have a second planar area A₂. In some embodiments, the second planar area A₂ may be less than or equal to the first planar area Ai. In some embodiments, the second planar area A ₂ may be in a range of about 50 cm² to about 150 cm². In some embodiments, the second planar area A ₂ may be in a range of about 50 cm² to about 100 cm². In some embodiments, the second planar area A₂ may be about 63 cm². The dimensions of the absorbent layers 315 may vary according to a prescribed therapy or application. [0090] As further shown in the example of Figure 4, the manifold 310 may have a width 421. In some embodiments, the width 421 of the manifold 310 may be less than the width 419 of the one or more absorbent layers 315. The narrower width 421 of the manifold 310 in comparison to the width

419 of the one or more absorbent layers 315 may focus the flow of fluid along the serpentine fluid path of the manifold 310 and may reduce bleed over around the sides of the manifold 310.

[0091] In some embodiments, one or more baffles, barriers, or weirs, such as baffles 420 may be disposed in the pouch 115. In some embodiments, the baffles 420 may be formed from or include a polymer fdm. In some embodiments, the baffles 420 may comprise a thermoplastic fdm or sheet. The baffles 420 may comprise, for example, one or more of the following materials: thermoplastic polyurethane (TPU); polyurethane (PU), such as hydrophilic polyurethane; cellulosics; hydrophilic polyamides; polyvinyl alcohol; polyvinyl pyrrolidone; hydrophilic acrylics; silicones, such as hydrophilic silicone elastomers; natural rubbers; polyisoprene; styrene butadiene rubber; chloroprene rubber; polybutadiene; nitrile rubber; butyl rubber; ethylene propylene rubber; ethylene propylene diene monomer; chlorosulfonated polyethylene; polysulfide rubber; ethylene vinyl acetate (EVA); co polyester; and polyether block polymide copolymers. In some embodiments, the baffles 420 may comprise one or more of a polymer film and a backing layer, such as, for example, a casting paper, a film, or polyethylene. Further, in some embodiments, the backing layer may be a polyester material such as polyethylene terephthalate (PET), or similar polar semi-crystalline polymer. In some embodiments, the baffles 420 may be fluid impermeable. For example, the baffles 420 may be configured to prevent the passage of liquid and gas through the baffles 420. In some embodiments, the baffles 420 may be configured to prevent the passage of liquid, but allow the passage of gas or vapor, through the baffles 420. In some embodiments, the baffles 420 may be formed of a material that is liquid impermeable. In some embodiments, the baffles 420 may be formed of a material that is gas impermeable. In some embodiments, the baffles 420 may be formed of a material that is liquid impermeable but gas permeable.

[0092] The one or more baffles 420 may have a length 422 and a width 424. In some embodiments, the length 422 of the baffles 420 may be less than or equal to the length 416 of the pouch 115. In some embodiments, the length 422 of the baffles 420 may be equal to the length 416 of the pouch 115 minus a thickness of the manifold 310. In some embodiments, the width 424 of the baffles

420 may be less than or equal to the width 417 of the pouch 115. In some embodiments, the width 424 of the baffles 420 may be about equal to the width 417 of the pouch 115. In some embodiments, the length 422 may be in a range of about 5 centimeters to about 20 centimeters and the width 424 may be in a range of about 5 centimeters to about 20 centimeters. In some embodiments, the length 422 may be about 9 centimeters and the width 424 may be about 7 centimeters. In some embodiments, the length 422 may be about 8.5 centimeters and the width 424 may be about 8.5 centimeters. As shown in the example of Figure 4, the baffles 420 may be coextensive or congruent with the absorbent layers 315. For example, each baffle 420 may have a third planar area As, wherein the third planar area As of each baffle 420 may be equal to the second planar area A 2 of each absorbent layer 315. If the third planar area As is equal to the second planar area A 2. the baffles 420 may be considered partial baffles. In some embodiments, the third planar area A < may be less than or equal to the first planar area A_/. In some embodiments, the third planar area A ; may be in a range of about 50 cm² to about 150 cm². In some embodiments, the third planar area A ; may be in a range of about 50 cm² to about 100 cm². In some embodiments, the third planar area A ; may be about 63 cm². The dimensions of the baffles 420 may vary according to a prescribed therapy or application. In some embodiments, the first planar area A _/ of the pouch 115, the second planar area A 2 of the absorbent layers 315, and the third planar area As of the baffles 420 may be parallel.

[0093] Figure 5 is a cross-sectional view of the pouch 115 of Figure 4 taken along line 5-5. As shown in Figure 5, the envelope 400 may have a first side 500 and a second side 505 opposite the first side 500. The inlet 320 may be on the first side 500 and the outlet 330 may be on the second side 505. The outlet 330 may be offset from the inlet 320. The manifold 310 and the one or more absorbent layers 315 may be in the interior space 405 of the envelope 400. The inlet 320 and the outlet 330 may be fluidly coupled with the interior space 405.

[0094] In some embodiments, the manifold 310 may comprise a population N_å of layers 510 and a population Nc of connectors 515, wherein the layers 510 and the connectors 515 are fluidly coupled. In some embodiments, each of the layers 510 of the manifold 310 may be parallel to one another. In some embodiments, the connectors 515 may be curved. In some embodiments, the population Nc of connectors 515 may be one less than the population N_L of layers 510 (e.g., N_C = N_{L ~} 1). The layers 510 and connectors 515 of the manifold 310 may have a thickness 516 in a range of about 1 millimeter to about 5 millimeters. In some embodiments, the thickness 516 may be about 2.5 millimeters.

[0095] The layer 510 of the manifold 310 proximate to the inlet 320 may be considered a first layer, such as an inlet layer 520. The layer 510 of the manifold 310 proximate to the outlet 330 may be considered a second layer, such as an outlet layer 525. The inlet layer 520 may have a first length 521 and the outlet layer 525 may have a second length 526. In some embodiments, the second length 526 may be less than the first length 526. In some embodiments, the second length 526 may be equal to the first length 521. As further shown in Figure 5, the inlet layer 520 of the manifold 310 may cover the inlet 320 and the outlet layer 525 of the manifold 310 may cover the outlet 330. In some embodiments, the inlet layer 520 may extend beyond the inlet 320 and the outlet layer 525 may extend beyond the outlet 330. In some embodiments, a portion of the manifold 310, such as the inlet layer 520, may be between the inlet 320 and an absorbent layer 315. In some embodiments, a portion of the manifold 310, such as the outlet layer 525, may be between the outlet 330 and an absorbent layer 315.

[0096] A population No of gaps 530 may be located between the layers 510. In some embodiments, the population No of gaps 530 may be one less than the population N_å of layers 510 (e.g., N_G = N_å - 1). In some embodiments, the population N_G of gaps 530 may be equal to the population Nc of connectors 515 (e.g., Nc, = Nc).

[0097] The pouch 115 may comprise a population N_A of absorbent layers 315. In some embodiments, an absorbent layer 315 may be disposed in each gap 530. The absorbent layers 315 may be proximate the layers 510 of the manifold 310. Fluid carried by the manifold 310 may flow from the layers 510 into, and be absorbed by, the absorbent layers 315. In some embodiments, the population N_A of absorbent layers 315 may be one less than the population N_å of layers 510 (e.g., N_A = N_L - 1). In some embodiments, the population N_A of absorbent layers 315 may be equal to the population Nc of connectors 515 (e.g., N_A = Nc). In some embodiments, the population N_A of absorbent layers 315 may be equal to the population N_G of gaps 530 (e.g., N_A = N_G). The absorbent layers 315 may have a thickness 535 in a range of about 0.5 millimeters to about 5 millimeters when dry. In some embodiments, the thickness 535 may be about 1 millimeter when dry. The thickness and/or population N_A of absorbent layers 315 may be varied to increase or decrease the liquid storage capacity of the pouch 115.

[0098] In some embodiments, the pouch 115 may include a population N_B of baffles 420. In some embodiments, a baffle 420 may be disposed in each gap 530. In some embodiments, a baffle 420 may be disposed between an absorbent layer 315 and a layer 510 of the manifold 310. In some embodiments, the baffles 420 may be coupled to the absorbent layers 315. The baffles 420 may be attached to the absorbent layers 315. In some embodiments, the baffles 420 may be coupled to the manifold 310. For example, the baffles 420 may be attached to a side of one or more of the layers 510 of the manifold 310. In some embodiments, the baffles 420 may be uncoupled from the envelope 400. For example, the baffles 420 may not be attached to the envelope 400. The baffles 420 may serve as a barrier or wall between a layer 510 of the manifold 310 and an absorbent layer 315, preventing fluid flow from the layer 510 of the manifold 310 and a side of the absorbent layer 315. In some embodiments, the baffles 420 may serve as an exudate barrier. The baffles 420 may be included so that the absorbent layers 315 can only absorb fluid from the layers 510 of the manifold on the side of the absorbent layer 315 opposite the baffle 420. The baffles 420 may promote the flow of fluid in a serpentine flow path through the manifold 310 and may regulate the rate of absorption by the absorbent layers 315.

[0099] In some embodiments, the population N_B of baffles 420 may be one less than the population N_å of layers 510 (e.g., N_B = N_L - 1). In some embodiments, the population N_B of baffles 420 may be equal to the population Nc of connectors 515 (e.g.. NB = Nc). In some embodiments, the population N_B of baffles 420 may be equal to the population N_G of gaps 530 (e.g., N_B = No). In some embodiments, the population N_B of baffles 420 may be equal to the population N_A of absorbent layers 315 (e.g., NB = N_A). [00100] As shown in the example of Figure 5, the population N_L of layers 510 may be 4, the population Ac of connectors 515 may be 3, the population Nr, of gaps 530 may be 3, the population N_A of absorbent layers 315 may be 3, and the population N_B of baffles 420 may be 3.

[00101] Figure 6 is a cross-sectional view of another example embodiment of the pouch 115 that can be associated with some embodiments of the therapy system 100. As shown in Figure 6, in some embodiments, the second length 526 of the outlet layer 525 may be equal to the first length 521 of the inlet layer 520. In some embodiments, the manifold 310 may extend beyond the outlet 330. In some embodiments, the pouch 115 may comprise one or more stacks 600, wherein each stack 600 comprises a layer 510 of the manifold 310 and an absorbent layer 315. As further shown in Figure 6, in some embodiments, each stack 600 may further comprise a baffle 420. The layers 510 in each stack 600 may be fluidly coupled to one another, for example, by the connectors 515.

[00102] Figure 7 is a cross-sectional view of another example embodiment of the pouch 115 that can be associated with some embodiments of the therapy system 100. As shown in Figure 7, in some embodiments, the population N_L of layers 510 may be 3 , the population Ac of connectors 515 may be 2, the population c of gaps 530 may be 2, the population N_A of absorbent layers 315 may be 2, and the population N_B of baffles 420 may be 2. In some embodiments, the absorbent layers 315 and the baffles 420 may be dimensioned such that three sides of the absorbent layers 315 and the baffles 420 may be proximate to or in contact with the one or more of the first layer 300 and the second layer 305. In some embodiments, three sides of the absorbent layers 315 and the baffles 420 may be proximate to or in contact with the interior of the envelope 400. The width 419 of the absorbent layers 315 and the width 424 of the baffles 420 may be about equal to the width 417 of the pouch 115. The length 418 of the absorbent layers 315 and the length 422 of the baffles 420 may be equal to the length 416 of the pouch 115 minus the thickness 516 of the manifold 310. Placing the absorbent layers 315 and the baffles 420 proximate to or in contact with the interior of the envelope 400 may reduce or eliminate the ability of liquid fluid to “short circuit” around the end of an absorbent layer 315 and/or baffle 420, thereby directing or promoting the fluid flow path to go through the manifold 310. A “short circuit” of the fluid flow may occur when fluid flows in a path outside of the manifold 310.

[00103] Figure 8 is a cross-sectional view of another example embodiment of the pouch 115 that can be associated with some embodiments of the therapy system 100. As shown in Figure 8, in some embodiments, the population N_L of layers 510 may be 2, the population Ac of connectors 515 may be 1, the population Ac of gaps 530 may be 1, the population N_A of absorbent layers 315 may be 1, and the population N_B of baffles 420 may be 1.

[00104] Figure 9 is a plan view of another example embodiment of the pouch 115 that can be associated with some embodiments of the therapy system 100. In some embodiments, the baffles 420 may be larger than the absorbent layers 315. For example, in some embodiments, the third planar area A of each baffle 420 may be greater than the second planar area A of each absorbent layer 315. If the third planar area As is greater than the second planar area A s. the baffles 420 may be considered full baffles. In some embodiments, the third planar area As of may be greater than second planar area of each absorbent layer 315 and less than or equal to the first planar area A _/ of the inner boundary line 415 of the envelope 400. In some embodiments, one or more of the baffles 420 may be coupled on three sides to one or more of the first layer 300 and the second layer 305. For example, one or more of the baffles 420 may be adhered to one or more of the first layer 300 and the second layer 305 in some embodiments. Suitable bonds between the one or more of the baffles 420 and one or more of the first layer 300 and the second layer 305 may include pressure-sensitive adhesive (reactive and non-reactive types); hot melt adhesive (spray applied or deployed as a film, woven, or non-woven); hot press lamination; or flame lamination. The baffles 420 may be coupled to the first layer 300 and/or the second layer 305 inside of the weld 410 and the inner boundary line 415, forming a bond 900.

[00105] Figure 10 is a cross-sectional view of the pouch 115 of Figure 9 taken along line 10- 10. As shown in example of Figure 10, the baffle 420 may be coupled to the first layer 300 of the envelope 400 along the bond 900. Coupling the baffle 420 to the envelope 400 may further promote the flow of fluid in a serpentine flow path through the manifold 310 and may regulate the rate of absorption by the absorbent layers 315. Additionally, coupling the baffle 420 to the envelope 400 may prevent a “short circuit” of the fluid flow from the inlet 320 to the outlet 330.

[00106] Figure 11 is a plan view of another example embodiment of the pouch 115 that can be associated with some embodiments of the therapy system 100. As shown in Figure 11, in some embodiments, one or more of the baffles 420 may have a width 424 greater than the width 417 of the pouch 115. In some embodiments, one or more of the baffles 420 may be coupled, such as by welding, on three sides to both the first layer 300 and the second layer 305. The baffles 420 may be welded to the first layer 300 and the second layer 305 under the weld 410. For example, the pouch in Figure 11 may comprise a first baffle 420a and a second baffle 420b. On a left edge 1100 and a right edge 1105 of the pouch 115, the weld 410 may be a weld of four layers: the first layer 300, the first baffle 420a, the second baffle 420b, and the second layer 305. On a bottom edge 1110 of the pouch 115, the weld 410 may be a weld of three layers: the first layer 300, the first baffle 420a, and the second layer 305. On a top edge 1115 of the pouch 115, the weld 410 may be a weld of three layers: the first layer 300, a second baffle 420b, and the second layer 305.

[00107] Figure 12 is a cross-sectional view of the pouch 115 of Figure 10 taken along line 12-12. As shown in Figure 12, in some embodiments, the first baffle 420a and the second baffle 420b may be coupled between the first layer 300 and the second layer 305 at the weld 410. The first baffle 420a and the second baffle 420b may be considered full baffles.

[00108] Figure 13 is a cross-sectional view of another example embodiment of the pouch 115 that can be associated with some embodiments of the therapy system 100. As shown in Figure 13, in some embodiments, the pouch 115 may comprise one or more wicking layers 1300 coupled to the absorbent layers 315. For example, the pouch 115 may include a population Nw of wicking layers 1300. In some embodiments, a wicking layer 1300 may be disposed in each gap 530. In some embodiments, a wicking layer 1300 may be disposed between an absorbent layer 315 and a layer 510 of the manifold 310. In some embodiments, a wicking layer 1300 may be disposed proximate an absorbent layer 315 opposite from a baffle 420. In some embodiments, two wicking layers 1300 may be disposed on either side of an absorbent layer 315. The wicking layers 1300 may aid in removal of liquid fluid from the manifold 310, where the liquid fluid may be absorbed by the absorbent layers 315. The wicking layers 1300 may comprise a wicking material having flow channels that support the flow of fluids through the width of the wicking layer 1300. In some embodiments, the wicking layers 1300 may comprise a non- woven material.

[00109] In some embodiments, the population Nw of wicking layers 1300 may be one less than the population N_å of layers 510 (e.g., Nw NL - 1). In some embodiments, the population Nw of wicking layers 1300 may be equal to the population Nc of connectors 515 (e.g., Nw = Nc). In some embodiments, the population Nw of wicking layers 1300 may be equal to the population Nc, of gaps 530 (e.g., Nw = No). In some embodiments, the population Nw of wicking layers 1300 may be equal to the population N_t of absorbent layers 315 (e.g., A¾ = N_t).

[00110] In use, the pouch 115 may be fluidly coupled to the dressing 110 at a tissue site and the negative-pressure source 105. Negative pressure may be applied to the dressing 110 by the negative- pressure source 105 through the pouch 115. Fluid may be removed from the tissue site and may flow through the first fluid conductor 205, the inlet interface 325, and the inlet 320 of the pouch 115 and into the manifold 310. Liquid fluid from the tissue site may be drawn from the manifold 310 into the absorbent layers 315. The serpentine shape of the manifold 310 may prevent collapse of the pouch 115 under negative pressure and may aid in maximizing the volume of liquid fluid that can be absorbed by the absorbent layers 315 and stored in the pouch 115.

[00111] As negative pressure is continued to be applied to the dressing 110, fluid is drawn toward and through each layer 510 and connector 515 of the manifold 310, where liquid fluid may be absorbed by each successive absorbent layer 315 disposed between the layers 510 of the manifold 310. For example, liquid fluid may be absorbed by a first absorbent layer 315 proximate to the inlet 320 of the pouch 115 and after this first absorbent layer 315 is filled, the liquid fluid may then go over a first baffle 420 proximate to the inlet 320 of the pouch 115, where the liquid fluid may be absorbed by the next absorbent layer 315. After that next absorbent layer 315 is filled, the liquid fluid may then go over the next baffle 420. This successive filling of absorbent layers 315 may continue until all absorbent layers 315 are full. The manifold 310 may provide an open fluid pathway for negative pressure to flow as the pouch 115 fills to capacity. The manifold 310 may provide a low-pressure drop flow path through the pouch 115 that may be unlikely to clog prior to the pouch 115 filling to capacity. Additionally, the serpentine shape of the manifold 310 may enhance the ability of negative pressure to be transmitted through the pouch 115 if the pouch 115 is in different orientations during use. The manifold 310 may promote even absorption of liquid fluid across the absorbent layers 315. The serpentine shape of the manifold 310 and the baffles 420 allow for the inclusion of the single fdter 340 at the outlet 330 of the pouch 115.

[00112] In some embodiments, the pouch 115 may have a first thickness between the first side 500 and the second side 505, prior to absorbing any wound fluid, in a range of about 0.5 centimeter to about 5 centimeters. For example, in some embodiments, the pouch 115 may have a first thickness of about 1 centimeter. In some embodiments, the pouch 115 may have a second thickness between the first side 500 and the second side 505, when the capacity for absorbing wound fluid has been reached, in a range of about 1 centimeter to about 5 centimeters. For example, in some embodiments, the pouch 115 may have a second thickness of about 2 centimeters. In some embodiments, the pouch 115 may have a second thickness of about 2.75 centimeters. In some embodiments, the pouch 115 may have a second thickness of about 3.25 centimeters. In some embodiments, the pouch 115 may have a second thickness of about 3.5 centimeters.

[00113] The population N_L of layers 510, the population Av of connectors 515, the population N_G of gaps 530, the population N_t of absorbent layers 315, the population A¾ of baffles 420, and the population Nw of wicking layers 1300, and/or the dimensions of the layers 510, the absorbent layers 315, the baffles 420, the wicking layers 1300, and the pouch 115 may vary according to a prescribed therapy or application. For example, for highly exudating tissue sites, a larger pouch 115 having a higher population N_L of layers 510, population Nr of connectors 515, population N of gaps 530, population N _t of absorbent layers 315, population N_B of baffles 420, and/or population Nw of wicking layers 1300 and/or larger layers 510, absorbent layers 315, baffles 420, and/or wicking layers 1300 may be used as compared to a pouch 115 used for tissue sites that exudate less wound fluid.

[00114] Figure 14 is a chart that illustrates how the population N_A of absorbent layers 315 can affect the fluid storage capacity of the pouch 115. Testing was conducted in which simulated wound fluid was instilled into various embodiments of the pouch 115 at the furthest point from the negative- pressure source. The simulated wound fluid was saline instilled at a rate of 0.833 ml/hour (20 ml/day) over a period of days. The pressure on the inlet side of the pouch 115 and the amount of simulated would fluid absorbed by the pouch 115 were monitored. Testing was conducted with five samples of the pouch 115 as shown in the below table:

capacity increased with increasing the population N_A of absorbent layers 315. With respect to Sample 1, the measured negative pressure fell below 100 mmHg with 45 ml instilled into the pouch 115 and fell below 75 mmHg with 56 ml instilled into the pouch 115. With respect to Sample 2, the measured negative pressure fell below 100 mmHg with 85 ml instilled into the pouch 115 and fell below 75 mmHg with 101 ml instilled into the pouch 115. With respect to Sample 3, the measured negative pressure fell below 100 mmHg with 115 ml instilled into the pouch 115. With respect to Sample 4, the measured negative pressure fell below 100 mmHg with 93 ml instilled into the pouch 115 and fell below 75 mmHg with 109 ml instilled into the pouch 115. With respect to Sample 5, the measured negative pressure fell below 100 mmHg with 41 ml instilled into the pouch 115 and fell below 75 mmHg with 54 ml instilled into the pouch 115.

[00116] Figure 15A, Figure 15B, and Figure 15C illustrate different orientations in which an embodiment of the pouch 115 was tested. Specifically, the impact of the orientation of the pouch 115 on the storage capacity of the pouch 115 was tested using three pouches 115 (115a, 115b, and 115c) constructed according to Figures 4 and 5. Testing was conducted in which simulated wound fluid was instilled into the three identical pouches 115a, 115b, and 115c at the furthest point from the negative- pressure source. The simulated wound fluid was saline instilled at a rate of 0.833 ml/hour (20 ml/day) over a period of days. The pressure on the inlet side of the three pouches 115 and the amount of simulated would fluid absorbed by the three pouches 115a, 115b, and 115c were monitored. The first pouch 115a was tested in the orientation as shown in Figure 15 A, wherein the length of the pouch 115a was oriented vertically with the inlet interface 325 at a higher elevation than the outlet interface 335. The measured negative pressure fell below 100 mmHg with 82 ml instilled (after 98 hours). The second pouch 115a was tested in the orientation as shown in Figure 15B, wherein the length of the pouch was placed at an angle with respect to a horizontal plane with the inlet interface 325 at a higher elevation than the outlet interface 335. The measured negative pressure fell below 100 mmHg with 90 ml instilled (after 108.5 hours). The third pouch 115c was tested in the orientation as shown in Figure 15C, wherein the length of the pouch was placed at an angle with respect to a horizontal plane with the outlet interface 335 at a higher elevation than the inlet interface 325. The measured negative pressure fell below 100 mmHg with 81 ml instilled (after 97 hours).

[00117] With typical pouches, when the outlet is positioned at a lower elevation than the inlet, the filter can become blocked before the pouch fills to capacity. However, when the pouch 115 was in the orientation of Figure 15B, the pouch 115 was able to absorb high amounts of liquid fluid over a long period of time before the measured negative pressure fell below 100 mmHg. This may have been due to the serpentine shape of the manifold 310 and the baffles 420 promoting successive filling of the absorbent layers 315 and reducing or eliminating blockage of the single filter 340 at the outlet interface 335.

[00118] The percentage difference between the instillation amount of the first pouch 115a in the orientation of Figure 15A and the installation amount of the second pouch 115b in the orientation of Figure 15B is 9.3%. The percentage difference between the instillation amount of the first pouch 115a in the orientation of Figure 15A and the installation amount of the third pouch 115c in the orientation of Figure 15C is 1.2%. The percentage difference between the instillation amount of the second pouch 115b in the orientation of Figure 15B and the installation amount of the third pouch 115c in the orientation of Figure 15C is 10.5%.

[00119] The percentage difference between the time it took the first pouch 115a in the orientation of Figure 15A to fall below 100 mmHg and the second pouch 115b in the orientation of Figure 15B to fall below 100 mmHg is 10.2%. The percentage difference between the time it took the first pouch 115a in the orientation of Figure 15A to fall below 100 mmHg and the third pouch 115c in the orientation of Figure 15C to fall below 100 mmHg is 1.0%. The percentage difference between the time it took the second pouch 115b in the orientation of Figure 15B to fall below 100 mmHg and the third pouch 115c in the orientation of Figure 15C to fall below 100 mmHg is 11.2%.

[00120] The data demonstrate that the pouch 115 may be used in multiple orientations without a significant impact on the amount of storage capacity of the pouch 115 or on how long the pouch 115 can be used before the negative pressure drops below 100 mmHg.

[00121] The systems, apparatuses, and methods described herein may provide significant advantages. For example, in some embodiments, the pouch 115 may be flexible, allowing the pouch 115 to conform to a portion of the body of the patient 200, thereby enhancing safety and comfort of the patient 200. In addition, the flexible nature of the pouch 115 may allow the pouch 115 to be stored in a small space. The pouch 115 may be relatively easy to manufacture and may be brought to market quicker due, as only simple tooling may be required to manufacture. The pouch 115 may also be easier to ship due to light weight and small size. Additionally, the pouch 115 does not require complicated device interface points, gaskets, or seals to be coupled with the negative-pressure source 105. The pouch 115 may also have a low profile which may allow a large number of pouches 115 to fit on a pallet, allowing a large number of pouches 115 to be sterilized at a time, and thereby reducing costs. Moreover, if the pouch 115 is used with animals, the flexible nature may help prevent injury, for example, if the animal bumps surfaces or rolls over.

[00122] As disclosed herein, the therapy system 100 can provide a flexible canister or pouch 115 that manifolds fluid and air to provide a low pressure drop and an increased spread of exudates and other fluids from the tissue site throughout the pouch 115. The inclusion of the serpentine manifold 310 and the baffles 420 may allow the pouch 115 to be used in multiple orientations without pooling of exudate within the pouch 115 orpremature blockage ofthe manifold 310 and/or filter 340. Furthermore, the thin felted manifold 310 may provide a flow path that resists collapse and remains open under the application of negative pressure. Additionally, the serpentine manifold 310 and the baffles 420 promote successive filling of the absorbent layers 315 in any orientation of the pouch allowing for the use of a single filter 340 at the outlet 330 of the pouch 115. Accordingly, the pouch 115 may be used with a single filter 340 instead of multiple filters disposed in multiple locations within the pouch 115. Multiple orientation use of the pouch 115 may permit use of the pouch 115 in a wider variety of locations, and persons. In addition, multiple orientation use of the pouch 115 may permit the pouch 115 to be used in a mobile environment.

[00123] 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 that fall within the scope of the appended claims. 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 110, the container 115, or both may be eliminated or separated from other components for manufacture or sale. In other example configurations, the controller 130 may also be manufactured, configured, assembled, or sold independently of other components.

[00124] 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 in the context of some embodiments may also be omitted, 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.

Claims

CLAIMS What is claimed is:

1. A fluid storage pouch comprising: a fluid impermeable envelope defining an interior space; an inlet in the envelope, the inlet fluidly coupled to the interior space; an outlet in the envelope, the outlet fluidly coupled to the interior space; a manifold in the interior space, the manifold comprising: a first layer having a first length; a second layer having a second length, the second layer fluidly coupled to the first layer; and an absorbent layer between the first layer and the second layer of the manifold.

2. The fluid storage pouch of claim 1, further comprising a wicking layer coupled to the absorbent layer.

3. The fluid storage pouch of any of claims 1-2, further comprising at least one fluid impermeable baffle, wherein the at least one fluid impermeable baffle is proximate to the absorbent layer.

4. The fluid storage pouch of claim 3, wherein the baffle is attached to the manifold.

5. The fluid storage pouch of claim 3, wherein the baffle is coupled to the absorbent layer.

6. The fluid storage pouch of claim 3, wherein the baffle is not attached to the envelope.

7. The fluid storage pouch of any of claims 1-6, wherein the manifold comprises an open-cell foam.

8. The fluid storage pouch of claim 7, wherein the open-cell foam has a density in a range of about 3.9 to about 14.7 lb/ft³.

9. The fluid storage pouch of any of claims 7-8, wherein the open-cell foam has a free volume in a range of about 13% to about 30%.

10. The fluid storage pouch of any of claims 7-9, wherein the open-cell foam has about 120 to about 350 pores per inch.

11. The fluid storage pouch of any of claims 7-10, wherein the open-cell foam has an average pore size in a range of about 57 to about 300 microns.

12. The fluid storage pouch of any of claims 1-11, wherein the manifold has a thickness of in a range of about 1 millimeter to about 5 millimeters.

13. The fluid storage pouch of any of claims 1-11, wherein the manifold has a thickness of about 2.5 millimeters.

14. The fluid storage pouch of any of claims 1-13, wherein the manifold covers the inlet.

15. The fluid storage pouch of any of claims 1-14, wherein the manifold covers the outlet.

16. The fluid storage pouch of any of claims 1-15, wherein the manifold extends beyond the outlet.

17. The fluid storage pouch of any of claims 1-16, wherein the manifold has a first width and the absorbent layer has a second width, the first width less than the first width.

18. The fluid storage pouch of any of claims 1-17, wherein the first layer of the manifold is parallel to the second layer of the manifold.

19. The fluid storage pouch of any of claims 1-18, wherein the first length of the first layer is greater than the second length of the second layer.

20. The fluid storage pouch of any of claims 1-18, wherein the first length of the first layer is equal to the second length of the second layer.

21. The fluid storage pouch of any of claims 1-20, wherein the manifold further comprises a third portion fluidly coupled to the first layer and the second layer.

22. The fluid storage pouch of any of claims 1-21, further comprising a filter disposed at the outlet.

23. The fluid storage pouch of any of claims 1-22, wherein the envelope has a first side and a second side opposite the first side.

24. The fluid storage pouch of claim 23, wherein the inlet is on the first side of the envelope and the outlet is on the second side of the envelope.

25. The fluid storage pouch of claim 24, wherein the outlet is offset from the inlet.

26. The fluid storage pouch of any of claims 1-25, wherein the envelope comprises a first envelope layer and a second envelope layer coupled to the first envelope layer.

27. The fluid storage pouch of claim 26, wherein the first envelope layer comprises a first polymer film.

28. The fluid storage pouch of any of claims 26-27, wherein the second envelope layer comprises a second polymer fdm.

29. The fluid storage pouch of any of claims 1-28, wherein the fluid storage pouch is a single chamber containing the manifold and the absorbent layer.

30. The fluid storage pouch of claim 29, wherein the manifold is foam.

31. A fluid storage pouch comprising: a flexible envelope defining an interior space; an inlet in the flexible envelope, the inlet fluidly coupled to the interior space; an outlet in the flexible envelope, the outlet fluidly coupled to the interior space; a manifold in the interior space, the manifold having a serpentine shape and configured to provide a fluid path between the inlet and the outlet; and an absorbent proximate to the manifold.

32. The fluid storage pouch of claim 31, wherein the manifold comprises a population N_L of layers and a population Nc of connectors, wherein the layers and the connectors are fluidly coupled.

33. The fluid storage pouch of claim 32, wherein N_C = N_L - 1.

34. The fluid storage pouch of any of claims 32-33, further comprising a population Nc of gaps between the population N_L of layers.

35. The fluid storage pouch of claim 34, wherein N_G = N_{L ~} 1.

36. The fluid storage pouch of claim 34, wherein Nc = Nc.

37. The fluid storage pouch of any of claims 34-36, wherein the absorbent comprises a population N i of absorbent layers.

38. The fluid storage pouch of claim 37, wherein an absorbent layer of the population N_t of absorbent layers is disposed in each gap of the population Nc of gaps.

39. The fluid storage pouch of claim 38, wherein N_A = N_{L ~} 1.

40. The fluid storage pouch of any of claims 34-39, further comprising a population

of baffles.

41. The fluid storage pouch of claim 40, wherein a baffle of the population A¾ of baffles is disposed in each gap of the population Nc of gaps.

42. The fluid storage pouch of claim 41, wherein Nn = N_r - 1.

43. The fluid storage pouch of any of claims 40-42, wherein at least one baffle of the population N_B of baffles is coupled to the flexible envelope.

44. The fluid storage pouch of any of claims 34-43, further comprising a population Nw of wicking layers.

45. The fluid storage pouch of claim 44, wherein a wicking layer of the population Nw of wicking layers is disposed in each gap of the population No of gaps.

46. The fluid storage pouch of claim 45, wherein Nw = N_L - 1.

47. The fluid storage pouch of any of claims 31-46, wherein the manifold comprises an open-cell foam.

48. The fluid storage pouch of claim 47, wherein the open-cell foam has a density in a range of about 3.9 to about 14.7 lb/ft³.

49. The fluid storage pouch of any of claims 47-48, wherein the open-cell foam has a free volume in a range of about 13% to about 30%.

50. The fluid storage pouch of any of claims 47-49, wherein the open-cell foam has about 120 to about 350 pores per inch.

51. The fluid storage pouch of any of claims 47-50, wherein the open-cell foam has an average pore size in a range of about 57 to about 300 microns.

52. The fluid storage pouch of any of claims 31-51, wherein the manifold has a thickness of in a range of about 1 millimeter to about 5 millimeters.

53. The fluid storage pouch of any of claims 31-51, wherein the manifold has a thickness of about 2.5 millimeters.

54. The fluid storage pouch of any of claims 31-53, wherein the manifold covers the inlet.

55. The fluid storage pouch of any of claims 31-54, wherein the manifold covers the outlet.

56. The fluid storage pouch of any of claims 31-55, wherein the manifold extends beyond the outlet.

57. The fluid storage pouch of any of claims 31-56, wherein the manifold has a first width and the absorbent layer has a second width, the first width less than the second width.

58. The fluid storage pouch of any of claims 31-57, further comprising a filter disposed at the outlet.

59. The fluid storage pouch of any of claims 31-58, wherein the flexible envelope has a first side and a second side opposite the first side.

60. The fluid storage pouch of claim 59, wherein the inlet is on the first side of the flexible envelope and the outlet is on the second side of the flexible envelope.

61. The fluid storage pouch of claim 60, wherein the outlet is offset from the inlet.

62. The fluid storage pouch of any of claims 31-61, wherein the flexible envelope comprises a first envelope layer and a second envelope layer coupled to the first envelope layer.

63. The fluid storage pouch of claim 62, wherein the first envelope layer comprises a first polymer film.

64. The fluid storage pouch of any of claims 62-63, wherein the second envelope layer comprises a second polymer film.

65. A fluid storage pouch comprising: a first layer having a first periphery; a second layer having a second periphery coupled to the first periphery forming an interior space; a first port in the first layer fluidly coupled to the interior space; a second port in the second layer fluidly coupled to the interior space; a serpentine fluid distributor disposed in the interior space, the serpentine fluid distributor comprising a plurality of fluid distributor layers and a plurality of gaps between the fluid distributor layers, the plurality of fluid distributor layers fluidly coupled to one another; and a plurality of fluid storage layers, one fluid storage layer of the plurality of fluid storage layers disposed in each gap.

66. The fluid storage pouch of claim 65, wherein a first fluid distributor layer of the plurality of fluid distributor layers covers the first port and wherein a second fluid distributor layer of the plurality of fluid distributor layers covers the second port.

67. The fluid storage pouch of claim 66, wherein the second fluid distributor layer extends beyond the second port.

68. The fluid storage pouch of any of claims 65-67, wherein the first layer comprises a first polymer film.

69. The fluid storage pouch of any of claims 65-68, wherein the second layer comprises a second polymer fdm.

70. The fluid storage pouch of any of claims 65-69, wherein the second layer is welded to the first layer, forming an inner boundary line.

71. The fluid storage pouch of claim 70, wherein the inner boundary line defines a first planar area.

72. The fluid storage pouch of claim 71, wherein the first planar area is in a range of about 50 cm² to about 150 cm².

73. The fluid storage pouch of claim 71, wherein the first planar area is in a range of about 75 cm² to about 100 cm².

74. The fluid storage pouch of claim 71, wherein the first planar area is about 93.5 cm².

75. The fluid storage pouch of any of claims 71-74, wherein one or more fluid storage layers of the plurality of fluid storage layers comprises a second planar area less than or equal to the first planar area.

76. The fluid storage pouch of claim 75, wherein the second planar area is in a range of about 50 cm² to about 150 cm².

77. The fluid storage pouch of claim 75, wherein the second planar area is in a range of about 50 cm² to about 100 cm².

78. The fluid storage pouch of claim 75, wherein the second planar area is about 63 cm².

79. The fluid storage pouch of any of claims 75-78, further comprising a plurality of walls, one wall of the plurality of walls disposed in each gap.

80. The fluid storage pouch of claim 79, wherein one or more walls of the plurality of walls are coupled to one or more of the first layer and the second layer.

81. The fluid storage pouch of any of claims 79-80, wherein one or more walls of the plurality of walls comprises a third planar area less than or equal to the first planar area.

82. The fluid storage pouch of claim 81, wherein the third planar area is in a range of about 50 cm² to about 150 cm².

83. The fluid storage pouch of claim 81, wherein the third planar area is in a range of about 50 cm² to about 100 cm².

84. The fluid storage pouch of claim 81, wherein the third planar area is about 63 cm².

85. The fluid storage pouch of claim 81, wherein the third planar area is equal to the second planar area.

86. The fluid storage pouch of claim 81, wherein the third planar area greater than the second planar area and less than the first planar area.

87. The fluid storage pouch of any of claims 65-86, wherein the serpentine fluid distributor comprises an open-cell foam.

88. The fluid storage pouch of claim 87, wherein the open-cell foam has a density in a range of about 3.9 to about 14.7 lb/ft³.

89. The fluid storage pouch of any of claims 87-88, wherein the open-cell foam has a free volume in a range of about 13% to about 30%.

90. The fluid storage pouch of any of claims 87-89, wherein the open-cell foam has about 120 to about 350 pores per inch.

91. The fluid storage pouch of any of claims 87-90, wherein the open-cell foam has an average pore size in a range of about 57 to about 300 microns.

92. The fluid storage pouch of any of claims 65-91, wherein the serpentine fluid distributor has a thickness of in a range of about 1 millimeter to about 5 millimeters.

93. The fluid storage pouch of any of claims 65-91, wherein the serpentine fluid distributor has a thickness of about 2.5 millimeters.

94. The fluid storage pouch of any of claims 65-93, wherein the serpentine fluid distributor has a first width and the plurality of fluid storage layers have a second width, the first width less than the second width.

95. The fluid storage pouch of any of claims 65-93, further comprising a filter disposed at the second port.

96. The fluid storage pouch of any of claims 65-95, wherein the second port is offset from the first port.

97. A fluid storage pouch comprising: a flexible envelope defining an interior space; an inlet fluidly coupled to the interior space; an outlet fluidly coupled to the interior space; and one or more stacks disposed in the interior space, each stack comprising: a manifold layer; and an absorbent layer.

98. The fluid storage pouch of claim 97, wherein a manifold layer of the one or more stacks covers the inlet.

99. The fluid storage pouch of claim 97, further comprising a first stack and a second stack disposed in the interior space, wherein the manifold layer of the first stack is fluidly coupled to the manifold layer of the second stack.

100. The fluid storage pouch of any of claims 97-98, further comprising an outlet manifold layer fluidly coupled to each manifold layer of the one or more stacks.

101. The fluid storage pouch of claim 100, wherein the outlet manifold layer covers the outlet.

102. The fluid storage pouch of any of claims 97-101, wherein each stack further comprises a baffle layer.

103. The fluid storage pouch of claim 102, wherein the baffle layer is proximate to the absorbent layer opposite the manifold layer.

104. The fluid storage pouch of any of claims 102-103, wherein the baffle layer is coupled to the flexible envelope.

105. The fluid storage pouch of any of claims 97-104, wherein the manifold layer has a first width and the absorbent layer has a second width greater than the first width.

106. The fluid storage pouch of any of claims 97-105, wherein the manifold layer comprises an open-cell foam.

107. The fluid storage pouch of claim 106, wherein the open-cell foam has a density in a range of about 3.9 to about 14.7 lb/ft³.

108. The fluid storage pouch of any of claims 106-107, wherein the open-cell foam has a free volume in a range of about 13% to about 30%.

109. The fluid storage pouch of any of claims 106-108, wherein the open-cell foam has about 120 to about 350 pores per inch.

110. The fluid storage pouch of any of claims 106-109, wherein the open-cell foam has an average pore size in a range of about 57 to about 300 microns.

111. The fluid storage pouch of any of claims 97-110, wherein the manifold layer has a thickness of in a range of about 1 millimeter to about 5 millimeters.

112. The fluid storage pouch of any of claims 97-110, wherein the manifold layer has a thickness of about 2.5 millimeters.

113. The fluid storage pouch of any of claims 97-112, further comprising a filter disposed at the outlet.

114. The fluid storage pouch of any of claims 97-113, wherein the flexible envelope has a first side and a second side opposite the first side.

115. The fluid storage pouch of claim 114, wherein the inlet is on the first side of the flexible envelope and the outlet is on the second side of the flexible envelope.

116. The fluid storage pouch of claim 114, wherein the outlet is offset from the inlet.

117. The fluid storage pouch of any of claims 97-116, wherein the flexible envelope comprises a first envelope layer and a second envelope layer coupled to the first envelope layer.

118. The fluid storage pouch of claim 117, wherein the first envelope layer comprises a first polymer film.

119. The fluid storage pouch of any of claims 117-118, wherein the second envelope layer comprises a second polymer film.

120. The systems, apparatuses, and methods substantially as described herein.