WO2021084445A1

WO2021084445A1 - Flexible canister having a foam pouch

Info

Publication number: WO2021084445A1
Application number: PCT/IB2020/060110
Authority: WO
Inventors: Roy Dory; Matthew Francis Ii Cavanaugh; Elizabeth TRIMBLE; Justin Rice
Original assignee: Kci Licensing, Inc.
Priority date: 2019-11-01
Filing date: 2020-10-28
Publication date: 2021-05-06

Abstract

Systems, methods, and apparatuses for storing fluid in a negative-pressure environment are described. For example, a fluid storage pouch can include a first pouch wall and a second pouch wall having an exterior edge of the second pouch wall coupled to an exterior edge of the first pouch wall to form a chamber. A first port is fluidly coupled to the chamber, and a second port is fluidly coupled to the chamber. A fluid storage media is disposed in the chamber. A fluid distributor is disposed adjacent to the fluid storage media, the fluid distributor providing a plurality of tortuous pathways between the first port and the second port.

Description

P001928W001SEC

FLEXIBLE CANISTER HAVING A FOAM POUCH

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of priority to U.S. Provisional Application No. 62/929,361, 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 in a negative-pressure therapy environment.

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 fluid storage 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 fluid storage pouch is described. The fluid storage pouch can include a first pouch wall and a second pouch wall. An exterior edge of the second pouch wall can be coupled to an exterior edge of the first pouch wall to form a chamber. A first port can be fluidly coupled to the chamber, and a second port can be fluidly coupled to the chamber. A fluid storage media can be disposed in the chamber, and a fluid distributor can be disposed adjacent to the fluid storage media. The fluid distributor can provide a plurality of tortuous pathways between the first port and the second port.

[0008] More generally, another fluid storage pouch is described. The fluid storage pouch can include a first film layer and a second film layer having a periphery coupled to a periphery of the first film layer to form a chamber. A weir can be disposed in the chamber and separate the chamber into a first storage area and a second storage area. A fluid inlet can be fluidly coupled to the first storage area, and a fluid outlet can be fluidly coupled to the second storage area. A first foam pouch can be disposed in the first storage area, and a second foam pouch can be disposed in the second storage area.

[0009] Alternatively, other example embodiments may describe another fluid storage pouch. The fluid storage pouch can include a first film layer and a second film layer having a periphery coupled to a periphery of the first film layer to form a chamber. A fluid inlet can be fluidly coupled to a first end of the chamber, and a fluid outlet can be fluidly coupled to a second end of the chamber. A plurality of foam layers can be disposed in the chamber, and a plurality of absorptive layers can be disposed in the chamber. Each absorptive layer can be positioned adjacent to a respective foam layer.

[0010] Another fluid storage pouch is also described herein, wherein some example embodiments include a first film layer and a second film layer having a periphery coupled to a periphery of the first film layer to form a chamber. A fluid inlet can be fluidly coupled to a first end of the chamber, and a fluid outlet can be fluidly coupled to a second end of the chamber. A foam block can be disposed in the chamber. The foam block can have a plurality of foam chambers. The fluid storage pouch can also include a plurality of absorptive layers, each absorptive layer disposed in a respective foam chamber. The fluid storage pouch can further include a plurality of impermeable layers, each impermeable layer disposed on a downstream side of a respective absorptive layer.

[0011] 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 [0012] Figure 1 is a functional block diagram of an example embodiment of a therapy system that can provide negative-pressure treatment and instillation treatment in accordance with this specification;

[0013] Figure 2 is a schematic view of a container illustrating additional details that can be associated with some embodiments of the therapy system of Figure 1;

[0014] Figure 3 is a detail view of a portion of a foam pouch illustrating additional details that can be associated with some embodiments of the container of Figure 2;

[0015] Figure 4 is a detail view of a portion of a fluid outlet illustrating additional details that can be associated with some embodiments of the container of Figure 2;

[0016] Figure 5 is a detail view of a portion of a bridge illustrating additional details that can be associated with some embodiments of the container of Figure 2;

[0017] Figure 6A is a schematic view of a container illustrating additional details that can be associated with some embodiments of the therapy system of Figure 1;

[0018] Figure 6B is a detail view of a portion of a fluid inlet illustrating additional details that can be associated with some embodiments of the container of Figure 6A;

[0019] Figure 7 is a schematic view of a container illustrating additional details that can be associated with some embodiments of the therapy system of Figure 1;

[0020] Figure 8 is a schematic view of a container illustrating additional details that can be associated with some embodiments of the therapy system of Figure 1;

[0021] Figure 9 is a schematic view of a container illustrating additional details that can be associated with some embodiments of the therapy system of Figure 1; and

[0022] Figure 10 is a detail view of a portion of a fluid storage apparatus illustrating additional details that can be associated with some embodiments of the container of Figure 9.

DESCRIPTION OF EXAMPLE EMBODIMENTS

[0023] The following description of example embodiments provides information that enables a person skilled in the art to make and use the subject matter set forth in the appended claims, but may omit certain details already well-known in the art. The following detailed description is, therefore, to be taken as illustrative and not limiting.

[0024] 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. [0025] 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, a surface wound, bone tissue, adipose tissue, muscle tissue, neural tissue, dermal tissue, vascular tissue, connective tissue, cartilage, tendons, or ligaments. 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. A surface wound, as used herein, is a wound on the surface of a body that is exposed to the outer surface of the body, such an injury or damage to the epidermis, dermis, and/or subcutaneous layers. Surface wounds may include ulcers or closed incisions, for example. A surface wound, as used herein, does not include wounds within an intra-abdominal cavity. 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.

[0026] 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. The therapy system 100 may include a source or supply of negative pressure, such as a negative -pressure source 102, a dressing 104, a fluid container, such as a container 106, and a regulator or controller, such as a controller 108, for example. Additionally, the therapy system 100 may include sensors to measure operating parameters and provide feedback signals to the controller 108 indicative of the operating parameters. As illustrated in Figure 1, for example, the therapy system 100 may include a pressure sensor 110, an electric sensor 112, or both, coupled to the controller 108. As illustrated in the example of Figure 1, the dressing 104 may comprise or consist essentially of a tissue interface 114, a cover 116, or both in some embodiments.

[0027] The therapy system 100 may also include a source of instillation solution. For example, a solution source 118 may be fluidly coupled to the dressing 104, as illustrated in the example embodiment of Figure 1. The solution source 118 may be fluidly coupled to a positive-pressure source such as a positive-pressure source 120, a negative-pressure source, such as the negative-pressure source 102, or both in some embodiments. A regulator, such as an instillation regulator 122, may also be fluidly coupled to the solution source 118 and the dressing 104 to ensure proper dosage of instillation solution (e.g. saline) to a tissue site. For example, the instillation regulator 122 may comprise a piston that can be pneumatically actuated by the negative-pressure source 102 to draw instillation solution from the solution source 118 during a negative-pressure interval and to instill the solution to the dressing 104 during a venting interval. Additionally or alternatively, the controller 108 may be coupled to the negative-pressure source 102, the positive-pressure source 120, or both, to control dosage of instillation solution to a tissue site. In some embodiments, the instillation regulator 122 may also be fluidly coupled to the negative-pressure source 102 through the dressing 104, as illustrated in the example of Figure 1. [0028] 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 102 may be combined with the solution source 118, the controller 108, and other components into a therapy unit.

[0029] In general, components of the therapy system 100 may be coupled directly or indirectly. For example, the negative-pressure source 102 may be directly coupled to the container 106, and may be indirectly coupled to the dressing 104 through the container 106. 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 102 may be electrically coupled to the controller 108, 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. For example, the tissue interface 114 and the cover 116 may be discrete layers disposed adjacent to each other, and may be joined together in some embodiments.

[0030] A distribution component is preferably detachable, and may be disposable, reusable, or recyclable. The dressing 104 and the container 106 are illustrative of distribution components. 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 104.

[0031] A negative-pressure supply, such as the negative-pressure source 102, 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 applied to a tissue site may vary according to therapeutic requirements, the pressure is generally a low vacuum, also commonly referred to as a rough vacuum, between -5 mm Hg (-667 Pa) and -500 mm Hg (-66.7 kPa). Common therapeutic ranges are between - 50 mm Hg (-6.7 kPa) and -300 mm Hg (-39.9 kPa).

[0032] The container 106 is representative of a container, canister, pouch, or other storage component, which can be used to manage exudates and other fluids withdrawn from a tissue site. In many environments, a rigid container may be preferred or required for collecting, storing, and disposing of fluids. In other environments, fluids may be properly disposed of without rigid container storage, and a re-usable container could reduce waste and costs associated with negative-pressure therapy.

[0033] A controller, such as the controller 108, may be a microprocessor or computer programmed to operate one or more components of the therapy system 100, such as the negative- pressure source 102. In some embodiments, for example, the controller 108 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 102, the pressure generated by the negative-pressure source 102, or the pressure distributed to the tissue interface 114, for example. The controller 108 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.

[0034] In some embodiments, the controller 108 may receive and process data from one or more sensors, such as the pressure sensor 110. The controller 108 may also control the operation of one or more components of the therapy system 100 to manage the pressure delivered to the tissue interface 114. In some embodiments, controller 108 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 114. 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 108. 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 108 can operate the negative-pressure source 102 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 114.

[0035] Sensors, such as the pressure sensor 110 or the electric sensor 112, 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 pressure sensor 110 and the electric sensor 112 may be configured to measure one or more operating parameters of the therapy system 100. In some embodiments, the pressure sensor 110 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 pressure sensor 110 may be a piezoresistive strain gauge. The electric sensor 112 may optionally measure operating parameters of the negative-pressure source 102, such as the voltage or current, in some embodiments. Preferably, the signals from the pressure sensor 110 and the electric sensor 112 are suitable as an input signal to the controller 108, but some signal conditioning may be appropriate in some embodiments. For example, the signal may need to be fdtered or amplified before it can be processed by the controller 108. Typically, the signal is an electrical signal, but may be represented in other forms, such as an optical signal.

[0036] The tissue interface 114 can be generally adapted to partially or fully contact a tissue site. The tissue interface 114 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 114 may be adapted to the contours of deep and irregular shaped tissue sites.

[0037] In some embodiments, the cover 116 may provide a bacterial barrier and protection from physical trauma. The cover 116 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 116 may be, for example, an elastomeric film or membrane that can provide a seal adequate to maintain a negative pressure at a tissue site for a given negative-pressure source. The cover 116 may have a high moisture- vapor transmission rate (MVTR) in some applications. For example, the MVTR may be at least 300 g/m² per twenty-four hours in some embodiments. In some example embodiments, the cover 116 may be a polymer drape, such as a polyurethane film, that is permeable to water vapor but impermeable to liquid. Such drapes typically have a thickness in the range of about 25 microns to about 50 microns. For permeable materials, the permeability generally should be low enough that a desired negative pressure may be maintained.

[0038] The cover 116 may comprise, for example, one or more of the following materials: hydrophilic polyurethane; cellulosics; hydrophilic polyamides; polyvinyl alcohol; polyvinyl pyrrolidone; hydrophilic acrylics; hydrophilic silicone elastomers; an INSPIRE 2301 material from Coveris Advanced Coatings of Wrexham, United Kingdom having, for example, an MVTR (inverted cup technique) of 14400 g/m²/24 hours and a thickness of about 30 microns; a thin, uncoated polymer drape; natural rubbers; polyisoprene; styrene butadiene rubber; chloroprene rubber; polybutadiene; nitrile rubber; butyl rubber; ethylene propylene rubber; ethylene propylene diene monomer; chlorosulfonated polyethylene; polysulfide rubber; polyurethane (PU); EVA film; co-polyester; silicones; a silicone drape; a 3M Tegaderm® drape; a polyurethane (PU) drape such as one available from Avery Dennison Corporation of Glendale, California; polyether block polyamide copolymer (PEBAX), for example, from Arkema, France; INSPIRE 2327; or other appropriate material.

[0039] An attachment device may be used to attach the cover 116 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 116 to epidermis around a tissue site. In some embodiments, for example, some or all of the cover 116 may be coated with an adhesive, such as an acrylic adhesive, which may have a coating weight between about 25 grams to about 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.

[0040] The solution source 118 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.

[0041] 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.

[0042] In general, exudates and other fluids flow toward lower pressure along a fluid path. Thus, the term “downstream” typically implies a position 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 a position 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.

[0043] Negative pressure applied across the tissue site through the tissue interface 114 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 container 106.

[0044] Tissue sites undergoing negative-pressure therapy may produce fluids, such as exudates, which can be removed from the tissue site to improve healing. Similarly, tissue sites undergoing instillation therapy may generate fluids that are removed following an instillation therapy dwell time. Negative-pressure therapy and instillation therapy systems may store the fluid prior to disposal of the fluid offsite. Fluids generated by a tissue site or used to instill a tissue site can be stored during therapy in many different ways, for example, by storing the fluid in a dressing at the tissue site or in a canister located way from the tissue site. Due in part to the size, fluid storage at the dressing may limit the total amount of fluid that can be stored, ultimately limiting the duration and type of tissue sites that can be treated. Fluid storage offsite, for example, at a therapy device, can increase the total volume of fluid that can be stored. However, fluid storage devices located away from a tissue site are often rigid and physically connected to a therapy device . This can limit the mobility of the patient using the therapy device. If the fluid storage device is located on or adjacent to a patient, a patient can experience pain or discomfort due to the rigid nature of the storage device if the patient inadvertently lies on the fluid storage device.

[0045] Furthermore, the ability of a canister to work efficiently can be dependent on its orientation during use. Canisters often include filters or filter assemblies to prevent fluids collected from a tissue site from reaching and potentially damaging a reduced-pressure source. As the canister fills with exudates and other fluids from the tissue site, the position of the filter in relationship to the fluid path may affect the performance of the canister. For example, a vertically oriented canister may have a port fluidly connected to the tissue site on an upper end of the flexible canister and a port fluidly connected to a reduced pressure source, such as a device connector, on a lower end of the flexible canister. Fluid may move through the canister from the port fluidly connected to the tissue site at the upper end to the device connector located at the lower end due to the force of the negative pressure and gravity. Once the fluid reaches the lower end of the canister it may be pulled across the device connector by the negative pressure. The canister may fill from the bottom upwards, and if the filter is positioned proximate to and in the fluid path of the device connector, the filter may become blocked prior to the canister being filled. Blockage of the filter may cause a pressure drop that triggers an alarm and causes the therapy to stop.

[0046] In addition, an absorbent may be disposed in the canister to store the liquids from the tissue site. Portions of the absorbent proximate to the device connector of the canister may be at full capacity, for example, completely saturated, when the pressure drop occurs. The pressure drop may be the result of a pooling effect caused by the absorbent being unable to retain any more liquid, allowing the liquid to pool proximate to the device connector and block the filter. As the canister fills from the lower end to the upper end, a large percentage of the absorbent may not be in proximity to the device connector and may not have been contacted by the liquid. Consequently, the absorbent may not fully absorb liquid, leaving a portion of the canister unfilled.

[0047] The therapy system 100 and the container 106 can resolve these and other issues. Specifically, the container 106 offers a simple, compact method of storing and managing tissue site effluent during negative-pressure therapy. The container 106 can be deployed with disposable negative- pressure therapy systems. Use of the container 106 with disposable negative-pressure therapy systems can increase the volume of fluid that can be managed by disposable negative-pressure therapy systems and expand the size and complexity of tissue sites that can be treated. The container 106 can readily conform to a carrying case and is free of hard points. The container 106 can have a smaller volume when empty than a rigid canister while storing the same volume of fluid as a rigid canister when full. Thus, the container 106 can occupy less space than a rigid canister during storage and provide the same fluid storage capacity during use.

[0048] The container 106 can comprise reticulated foam encased absorbent material within a flexible, durable pouch. Encasing the absorbent material within reticulated foam can provide a plurality of fluid pathways within the container 106. The plurality of fluid pathways can allow the container 106 to be stored in several orientations without disrupting transmission of negative pressure as the container 106 fdls with liquid. The container 106 can have a fluid inlet on a dressing-side that enables fluid, including liquid and gas, to enter the container 106, while a hydrophobic filter at the outlet allows flow of gas out of the container 106 but prevents liquids from exiting the container 106. The foam- encased absorbent material can be separated by a weir that directs fluid flow from the fluid inlet to the fluid outlet through a tortuous fluid pathway, maximizing fluid contact with the absorbent material. Maximization of contact between the fluid and the absorbent material can encourage the absorbent material to fill serially to ensure the absorbent material achieves its maximum liquid capacity. In some embodiments, the absorbent material in the container 106 can comprise absorbent pellets that are retained in the container 106 by the foam, which has a pore size that is smaller than the absorbent pellet size.

[0049] In some embodiments, the container 106 can be collocated with the negative-pressure source 102, stored in line between the dressing 104 and the negative-pressure source 102, or collocated with the dressing 104. The container 106 can also feature materials used in current dressing constructions and may offer simplified manufacturing processes and lower manufacturing costs relative to a rigid canister. In some embodiments, the container 106 can expand as liquid from the tissue site fills the container 106. The edges of the container 106 may also have a pleated construction to facilitate the expansion of the container 106.

[0050] Figure 2 is a schematic diagram illustrating additional details that may be associated with some example embodiments of the container 106 of Figure 1. The container 106 can generally be a fluid pouch formed from a film material. For example, the container 106 can include a first sheet 202 and a second sheet 204. In another example, the first sheet 202 and the second sheet 204 may be a first wall or first pouch wall and a second wall or second pouch wall, respectively. A perimeter portion of the first sheet 202 may be coupled to a perimeter portion of the second sheet 204. For example, the first sheet 202 can be coupled to the second sheet 204 at a weld 206. In some embodiments, the perimeter portion may be a portion of the first sheet 202 and the second sheet 204 adjacent to an edge of the first sheet 202 and the second sheet 204. The perimeter portion of the first sheet 202 and the second sheet 204 can have a width about equal to the width of the weld 206. The width of the weld 206 may be dependent, in part, on the type of material of the first sheet 202 and the second sheet 204 and the amount of the material needed to couple the first sheet 202 to the second sheet 204 so that fluid may not flow across the weld 206. The weld 206 may extend around a circumference of the first sheet 202 and the second sheet 204 so that first sheet 202 is sealed to the second sheet 204 and vice versa. In some embodiments, the weld 206 can form a flange on an exterior of the container 106. In other embodiments, the weld 206 can be overlapping portions of the perimeter portions, or periphery, of the first sheet 202 and the second sheet 204.

[0051] In some embodiments, the weld 206 can be formed by hot gas welding, heat sealing, contact welding, friction welding, or other similar film welding techniques. In other embodiments, the weld 206 can comprise a bond between the first sheet 202 and the second sheet 204. The weld 206 can also comprise an adhesive configured to join the perimeter portion of the first sheet 202 to the perimeter portion of the second sheet 204. In still other embodiments, the weld 206 can comprise a coupling formed by welding 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. The container 106 may have a first end 220 and a second end 222. The second end 222 may be opposite the first end 220.

[0052] In other embodiments, at least a portion of each of the first sheet 202 and the second sheet 204 are formed from a single piece of continuous material; in this embodiment, all of the first sheet 202 and the second sheet 204 may be formed from a single piece of continuous material. The first sheet 202 and the second sheet 204 can also be manipulated or formed to have one or more pockets, for example, by stretching, heat forming, cold forming, or otherwise working the first sheet 202 and the second sheet 204. Forming of the first sheet 202 and the second sheet 204 can create pockets or cavities that increase the volume of the interior space 208. In some embodiments, the first sheet 202 and the second sheet 204 can be transparent. The transparency of either or both of the first sheet 202 and the second sheet 204 can expose the amount of liquid from the tissue site that is stored in the container 106, permitting observational determination of the fill status of the container 106. In other embodiments, the first sheet 202, the second sheet 204, or both can be translucent or opaque.

[0053] The first sheet 202 and the second sheet 204 may be formed from a flexible, stretchable, expandable, and/or rigid material, such as a polymer film. In some embodiments, the first sheet 202 and the second sheet 204 can be formed from polymer films of various thicknesses including polyurethane, polypropylene, PVC, polyethylene, and/or polyamides, as well as coated fabrics or laminations of one or more materials. In some embodiments, the first sheet 202 and the second sheet 204 may comprise a thermoplastic film or sheet. The first sheet 202 and the second sheet 204 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. [0054] The first sheet 202 and the second sheet 204 can also be formed from a low moisture- vapor transmission rate (MVTR) durable polymer. For example, the first sheet 202 and the second sheet 204 may both be formed from or include a polymeric film. In other embodiments, one or more of the first sheet 202 and the second sheet 204 may have a high moisture-vapor transmission rate (MVTR). 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 sheet 202 and the second sheet 204 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 sheet 202 and the second sheet 204 have a high MVTR, some of the fluids in the container 106 may evaporate and exit the pouch through one or more of the first sheet 202 and the second sheet 204 as water vapor. This may increase the storage capacity of the container 106.

[0055] The first sheet 202, the second sheet 204, and the weld 206 can form an interior space 208. The interior space 208 may be fluidly isolated from the ambient environment. In some embodiments, a baffle, barrier, or weir 210 can be disposed in the interior space 208. The weir 210 may divide the interior space 208 into a first chamber 212 and a second chamber 214. In some embodiments, the weir 210 can be formed by the inclusion of additional material in the interior space 208 that is separately coupled to the first sheet 202 and the second sheet 204. For example, a film can be disposed in the interior space 208 and adhered to each of the first sheet 202, the second sheet 204, and the weld 206 to form the first chamber 212 and the second chamber 214. In some embodiments, the weir 210 can be disposed between the first sheet 202 and the second sheet 204 at the flange 206 and extend across the interior space 208. For example, the weir 210 can comprise a film separating the first sheet 202 from the second sheet 204. The process of coupling the first sheet 202 to the second sheet 204 at the weld 206 can couple the weir 210 to the first sheet 202 and the second sheet 204 at the weld 206, forming the first chamber 212 and the second chamber 214.

[0056] In other embodiments, the weir 210 can be formed by coupling non-peripheral portions of the first sheet 202 to non-peripheral portions of the second sheet 204. For example, the first sheet 202 can be coupled to the second sheet 204 at a location in the interior space 208 that is at least partially separated from the weld 206. In some embodiments, the coupling of the first sheet 202 to the second sheet 204 to form the weir 210 can be accomplished by welding, adhesion, or bonding. For example, the weir 210 can be formed by hot gas welding, heat sealing, contact welding, friction welding, or other similar film welding techniques of joining or coupling the first sheet 202 to the second sheet 204. In still other embodiments, the weir 210 can comprise a coupling formed by welding using 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 other embodiments, the weir 210 can comprise a bond between the first sheet 202 and the second sheet 204. The weir 210 can also comprise an adhesive configured to join an interior portion of the first sheet 202 to an interior portion of the second sheet 204 separating the interior space 208 into the first chamber 212 and the second chamber 214.

[0057] The first chamber 212 and the second chamber 214 can be fluidly isolated from each other across the weir 210. For example, the first chamber 212 and the second chamber 214 can be fluidly isolated from each other by the weir 210. In some embodiments, the first chamber 212 and the second chamber 214 can comprise fluid storage chambers or fluid storage areas.

[0058] In some embodiments, a fluid inlet 216 can be fluidly coupled to the first chamber 212, and a fluid outlet 218 can be fluidly coupled to the second chamber 214. The fluid inlet 216 and the fluid outlet 218 can be disposed in the first end 220 of the container 106. The fluid inlet 216 is configured to fluidly couple another device or object to the first chamber 212, and the fluid outlet 218 is configured to fluidly couple another device or object to the second chamber 214. In some embodiments, the fluid inlet 216 and the fluid outlet 218 can be disposed proximate to the first end 220 of the interior space 208. In some embodiments, a one-way valve, such as a duckbill valve can be fluidly coupled to the fluid inlet 216. For example, the one-way valve can be positioned to permit fluid flow from the dressing 104 into the container 106 and prevent fluid flow from the container 106 into the dressing 104.

[0059] In some embodiments, a bridge 224 can be disposed in the weir 210. The bridge 224 can fluidly couple the first chamber 212 to the second chamber 214 across the weir 210. Preferably, the bridge 224 is positioned at an opposite end of the container 106 from the fluid inlet 216 and the fluid outlet 218. For example, the bridge 224 can be disposed in the weir 210 proximate to the second end 222 of the container 106. In some embodiments, the weir 210 is disposed between the fluid inlet 216 and the fluid outlet 218. For example, the weir 210 may extend from the first end 220 toward the second end 222, interrupting a direct fluid path between the fluid inlet 216 and the fluid outlet 218 at the first end 220.

[0060] A fluid storage device, such as a first foam pouch 226 can be disposed in the first chamber 212, and a second foam pouch 228 can be disposed in the second chamber 214. The first foam pouch 226 and the second foam pouch 228 can be configured to store liquid from the tissue site by absorbing and retaining the liquid. The first foam pouch 226 and the second foam pouch 228 can also provide a plurality of fluid pathways in the first chamber 212 and the second chamber 214, respectively, to manifold fluid within the interior space 208. The first foam pouch 226 and the second foam pouch 228 can be fluidly coupled to each other through the bridge 224. In some embodiments, the container 106 can include the first foam pouch 226 and the second foam pouch 228, the first foam pouch 226 alone, or the second foam pouch 228 alone. In other embodiments, the container 106 can include additional weirs 210 forming additional fluid chambers within the interior space 208. Further fluid storage devices, such as the first foam pouch 226 can be disposed in the additional fluid chambers formed by the additional weirs 210.

[0061] Figure 3 is a detail view of a portion of the second foam pouch 228 illustrating additional details that may be associated with some embodiments. The first foam pouch 226 and the second foam pouch 228 can be similarly constructed. The second foam pouch 228 can include a fluid storage media, such as an absorbent core 302, and at least one fluid distributor. In some embodiments, the fluid distributor can include a first manifold layer 304 and a second manifold layer 306. In some embodiments, the first manifold layer 304 can be positioned adjacent to the first manifold layer 304, and the second manifold layer 306 can be positioned adjacent to the first manifold layer 306. The first manifold layer 304 can surround or enclose the absorbent core 302, and the second manifold layer 306 can surround or enclose the first manifold layer 304.

[0062] A fluid storage media, such as the absorbent core 302, can be formed from an absorbent material configured to retain liquid. For example, the absorbent core 302 can be formed from a superabsorbent polymer (SAP). Generally, relative to their mass, SAPs can absorb and retain large quantities of liquid, and in particular water. Many medical disposables, such as canisters and dressings, use SAPs to hold and stabilize or solidify wound fluids. The SAPs used to form the absorbent core 302 may be of the type often referred to as “hydrogels,” “super-absorbents,” or “hydrocolloids.” The SAPs may be formed into fibers or spheres to manifold negative pressure until the SAPs become saturated. Spaces or voids between the fibers or spheres may allow a negative pressure that is applied to the absorbent core 302 to be transferred within and through the absorbent core 302. In some embodiments, fibers of the absorbent core 302 may be either woven or non-woven.

[0063] 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.

[0064] 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.

[0065] In some embodiments, the absorbent core 302 can be formed from a KERRAMAX CARE™ Super-Absorbent Dressing material available from Kinetic Concepts, Inc. of San Antonio, Texas. For example, the absorbent core 302 can be a super absorbent laminate composed of 304 GSM favor-PAC 230 superabsorbent powder glued by PARFRA 8667 adhesive between two layers of 50 gsm LIDRO non-woven material. The absorbent core 302 can be formed from one or more layers of SAP material having a thickness between about 0.5 mm and about 4.0 mm and preferably about 1.0 mm. In some embodiments, the absorbent core 302 may comprise an absorbent available from Gelok International. The presence of the absorbent core 302 may also help to minimize fluid loss or reflux.

[0066] The absorbent core 302 can also be formed from a plurality of absorbent pellets. For example, the plurality of pellets can be formed from an SAP. The pellets can be disposed in a permeable layer, such as a woven or non-woven fabric material configured to manifold fluid. In other embodiments, the pellets can be disposed in the second foam pouch 228 without a woven or non-woven fabric material. For example, the absorbent pellets can be surrounded by the first manifold layer 304, which may be a porous material having an average pore size that is smaller than an average effective diameter of the absorbent pellets. The absorbent pellets may be too large to pass through the pores of the first manifold layer 304, permitting the first manifold layer 304 to secure the absorbent pellets.

[0067] The absorbent core 302 can lock in fluid and prevent exudate from exiting the container 106. In some embodiments, the absorbent core 302 can reverse flowing to the fluid inlet 216 if an external force is applied to the container 106. The absorbent core 302 can also lock in liquid and limit the amount of liquid from escaping if the container 106 is detached from negative pressure during removal of the container 106 or change of the dressing 104.

[0068] A fluid distributor, such as the first manifold layer 304 and the second manifold layer 306, can provide a plurality of pathways for the flow of fluid for distribution or collection of the fluid. In some illustrative embodiments, the fluid distributor 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, a fluid distributor may additionally or alternatively comprise projections that form interconnected fluid pathways. For example, the fluid distributor may be molded to provide surface projections that define interconnected fluid pathways.

[0069] In some embodiments, the fluid distributor may be formed by a felting process. Any porous foam suitable for felting may be used, including the example foams mentioned herein, such as GRANUFOAM™ Dressing. 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.

[0070] 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.

[0071] 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.

[0072] 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 fluid distributor formed from felted foam may be about 5. In other embodiments, the firmness factor of the fluid distributor formed from felted foam may be about 3. There is a general linear relationship between firmness level, density, pore size (or pores per inch) and compressibility. 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. The physical properties of a felted foam in relation to the physical properties of an pre-felted foam may be determined by the following equations:

Density_Felted = Density_Unfelted x Firmness Factor

Average Pore Size_Unf elted

Average Pore Size_Feitecl =

Firmness Factor

Free Volume Unfelted

Free Volume Felted Firmness Factor

Average Pores per Inch_Feited = Average Pores Per Inch_Unf_eited x Firmness Factor 25% Compression Load Deflection_Feited = 25% Compression Load Deflection_Unf_eited x Firmness Factor 65% Compression Load Deflection_Feited = 65% Compression Load Deflection_Unf_eited x Firmness Factor 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.

[0073] In some embodiments, a suitable foam blank (e.g. of pre-felted foam) for formation of the fluid distributor may have about 40 to about 50 pores per inch on average, a density of about 0.02 g/cm³ to about 0.03 g/cm³, 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™ Dressing. 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 fluid distributor. 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 3-10. Some embodiments may felt the foam blank to a firmness factor of 5.

[0074] In some embodiments, a fluid distributor may comprise an open-cell foam having a free volume in a range of about 13% to about 30%, a density of about 0.06 g/cm³ to about 1.8 g/cm³, 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 than a less dense foam. In some embodiments, the density of the foam of the fluid distributor may be about 0.10 g/cm³ to about 0.13 g/cm³. In some embodiments, the free volume of the foam may be about 18%. In some embodiments, the average pore size of the fluid distributor may be about 80 to about 120 micron. In some embodiments, the fluid distributor may have about 200 to about 250 pores per inch on average. In some embodiments, the fluid distributor 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 foam of the fluid distributor 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 foam of the fluid distributor may have a 25% compression load deflection of about 1.05 to about 3.5 pounds per square inch and a 65% compression load deflection of about 1.29 to about 4.30 pounds per square inch.

[0075] In some embodiments, the fluid distributors can have different density or firmness factors. For example, the a first fluid distributor may be an open-cell, reticulated polyurethane foam such as a V.A.C. VERAFFO™ dressing, available from Kinetic Concepts, Inc., of San Antonio, Texas. The first fluid distributor may have a density of between about 1.7 pounds per foot³ (lb/ft³) or 0.027 grams per centimeter³ (g/cm³) and about 2.1 lb/ft³ or 0.034 g/cm³. The first fluid distributor can have a pore size between about 40 pores per inch (ppi) and about 50 ppi. In some embodiments, the first fluid distributor may have a 25% compression load deflection of at least 0.35 pounds per square inch, and the 65% compression load deflection may be at least 0.60 pounds per square inch. In some embodiments, the tensile strength of the first fluid distributor may be at least 10 pounds per square inch (psi) and up to about 18 psi. The first fluid distributor may have a tear strength of at least 2.5 pounds per inch and up to about 4.0 pounds per inch. A compression set 50% of the first fluid distributor can be about 10%. The first fluid distributor may be a non-felted foam or have a firmness factor of 1.

[0076] A second fluid distributor can be formed from a felted foam. For example, the second fluid distributor can be formed from a felted foam having density three times its non-felted density, or a firmness factor of 3. In some embodiments, the second fluid distributor can be formed from a V.A.C. VERAFLO™ Dressing, available from Kinetic Concepts, Inc., of San Antonio, Texas that is felted to have a density three times its non-felted density. For example, non-felted V.A.C. VERAFFO™ Dressing may have a density between about 1.7 pounds per foot³ (lb/ft³) or 0.027 grams per centimeter³ (g/cm³) and about 2.1 lb/ft³ or 0.034 g/cm³. If the V.A.C. VERAFFO™ Dressing is compressed to have a firmness factor (FF) of 3, the V.A.C. VERAFFO™ Dressing may be compressed until the density of the V.A.C. VERAFFO™ Dressing is between about 0.081 g/cm³ and about 0.102 g/cm³. The second fluid distributor can have a pore size between about 120 pores per inch (ppi) and about 150 ppi. In some embodiments, the second fluid distributor may have a 25% compression load deflection of at least 1.05 pounds per square inch, and the 65% compression load deflection may be at least 1.29 pounds per square inch. In some embodiments, the second fluid distributor may have a thickness between about 3 mm and about 40 mm and, preferably, about 6.35 mm or about 6.5 mm.

[0077] In other embodiments, the second manifold layer 306 can be formed from V.A.C. ^® GRANUFOAM™ Dressing that is felted to have a density three times its non-felted density. For example, V.A.C. ^® GRANUFOAM™ Dressing may have a density between about 0.02 grams per centimeter³ (g/cm³) and about 0.03 g/cm³ in its uncompressed state. If the V.A.C.^® GRANUFOAM™ Dressing is compressed to have a firmness factor (FF) of 3, the V.A.C.^® GRANUFOAM™ Dressing may be compressed until the density of the V.A.C.^® GRANUFOAM™ Dressing is between about 0.06 g/cm³ and about 0.09 g/cm³.

[0078] In some embodiments, the first manifold layer 304 can have a first density or firmness factor, and the second manifold layer 306 can have a second density or firmness factor. The second density can be greater than the first density. For example, the first manifold layer 304 may be an open cell, reticulated polyurethane foam such as a V.A.C. VERAFFO™ dressing, available from Kinetic Concepts, Inc., of San Antonio, Texas. In some embodiments, the first manifold layer 304 may have a thickness between about 3 mm and about 40 mm and, preferably, about 6.35 mm or about 6.5 mm. The second manifold layer 306 can be formed from a felted foam. For example, the second manifold layer 304 can be formed from a felted foam having density three times its non-felted density, or a firmness factor of 3. In some embodiments, the second manifold layer 306 can be formed from a V.A.C. VERAFFO™ Dressing, available from Kinetic Concepts, Inc., of San Antonio, Texas that is felted to have a density three times its non-felted density. In some embodiments, the second manifold layer 306 may have a thickness between about 3 mm and about 40 mm and, preferably, about 6.35 mm or about 6.5 mm.

[0079] The first manifold layer 304 can be disposed adjacent to and surround the absorbent core 302. The second manifold layer 306 can be disposed adjacent to and surround the first manifold layer 304. In some embodiments, the second manifold layer 306 may be denser than the first manifold layer 305. The increased density of the second manifold layer 306 can encourage fluid flow from the second manifold layer 306 into the first manifold layer 304, and the first manifold layer 305 into the absorbent core 302.

[0080] In some embodiments, the first manifold layer 304 and the second manifold layer 306 may have pores. The pores can be oriented to promote a direction of fluid flow toward the absorbent core 302. For example, the orientation of the pores in the second manifold layer 306 can encourage fluid flow into the first manifold layer 304 from the second manifold layer 306. Similarly, the orientation of the pores in the first manifold layer 304 can encourage fluid flow into the absorbent core 302 from the first manifold layer 304. In some embodiments, the orientation of the pores may vary along the fluid path or within a fluid distributor to maximize efficient liquid absorption while maintaining an open pathways for fluids. In some embodiments, the foam of the second manifold layer 306 may be cut perpendicular to the felting direction to provide pore structures that run parallel to the fluid path created by the second manifold layer 306. For example, the smaller pores that form perpendicular to the direction of felting may be oriented along the length of the second manifold layer 306. The larger pores that are parallel to the direction of felting may face the first manifold layer 304 and the absorbent core 302. The air in the fluid flowing through the second manifold layer 306 may flow through the smaller pores without a significant pressure drop, while the liquid in the fluid flowing through the second manifold layer 306 may fall through the larger pores and into the first manifold layer 304 and the absorbent core 302. Orienting the length of the second manifold layer 306 perpendicular to the felting direction may assist with reducing pressure drop across the second manifold layer 306, may increase the manifolding of fluid through the second manifold layer 306, and may increase the amount of liquid absorbed by the absorbent ore 302.

[0081] In some embodiments, the first manifold layer 304, the second manifold layer 306, and/or both can have a hydrophobic coating. The first manifold layer 304 may have a first coating having a first hydrophobicity, and the second manifold layer 306 may have a second coating have a second hydrophobicity. In some embodiments, the second manifold layer 306 may be more hydrophobic than the first manifold layer 305, encouraging fluid flow from the second manifold layer 306 into the first manifold layer 304. The first manifold layer 305 can also be hydrophobic, encouraging liquid flow from the first manifold layer 305 into the absorbent core 302.

[0082] In some embodiments, the second foam pouch 228 can include the first manifold layer 304 and the second manifold layer 306. In other embodiments, the second foam pouch 228 can include the first manifold layer 304 only, the second manifold layer 306 only, or additional manifold layers. In some embodiments, the first manifold layer 304 and the second manifold layer 306 can allow for uniform fluid movement from the fluid inlet 216 to the fluid outlet 218.

[0083] In some embodiments, a barrier layer 308 can be disposed between the second manifold layer 306 and the second sheet 204 of the container 106. The barrier layer 308 can be a non-permeable film or an adhesive layer coupling the second manifold layer 306 to the second sheet 204. In some embodiments, the barrier layer 308 can direct fluid movement through the second foam pouch 228 rather than around the second foam pouch 228. The barrier layer 308 may comprise, for example, one or more of the following materials: hydrophilic polyurethane; cellulosics; hydrophilic polyamides; polyvinyl alcohol; polyvinyl pyrrolidone; hydrophilic acrylics; hydrophilic silicone elastomers; an INSPIRE 2301 material from Coveris Advanced Coatings of Wrexham, United Kingdom having, for example, an MVTR (inverted cup technique) of 14400 g/m²/24 hours and a thickness of about 30 microns; a thin, uncoated polymer drape; natural rubbers; polyisoprene; styrene butadiene rubber; chloroprene rubber; polybutadiene; nitrile rubber; butyl rubber; ethylene propylene rubber; ethylene propylene diene monomer; chlorosulfonated polyethylene; polysulfide rubber; polyurethane (PU); EVA film; co-polyester; silicones; a silicone drape; a 3M Tegaderm® drape; a polyurethane (PU) drape such as one available from Avery Dennison Corporation of Glendale, California; polyether block polyamide copolymer (PEBAX), for example, from Arkema, France; INSPIRE 2327; or other appropriate material.

[0084] An attachment device may be used to attach the barrier layer 308 to the second manifold layer 306. The attachment device may take many forms. For example, an attachment device may be a medically-acceptable, pressure-sensitive adhesive configured to bond the barrier layer 308 to the second manifold layer 306. In some embodiments, for example, some or all of the barrier layer 308 may be coated with an adhesive, such as an acrylic adhesive, which may have a coating weight between about 25 grams to about 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. In some embodiments, the barrier layer 308 may have an attachment device on a first surface configured to couple the barrier layer 308 to the second manifold layer 306 and another attachment device on a second surface configured to couple the barrier layer 308 to one or more of the first sheet 202, the second sheet 204, and the weir 210. In some embodiments, the attachment device on the first surface of the barrier layer 308 and the attachment device on the second surface of the barrier layer 308 may be formed from the same material, such as a same adhesive. In other embodiments, the attachment device on the first surface of the barrier layer 308 and the attachment device on the second surface of the barrier layer 308 may be different, such as different adhesives configured to bond to different materials.

[0085] Figure 4 is a detail view of the fluid outlet 218 illustrating additional details that may be associated with some embodiments. The fluid outlet 218 can be a fluid port or other device configured to provide fluid communication across the second sheet 204. In some embodiments, the fluid outlet 218 may have one or more lumens 402 configured to provide a fluid path through the fluid outlet 218. The fluid outlet 218 can include a flange 404. The flange 404 can be coupled to the second sheet 204. The second sheet 204 can have an aperture 410 proximate to the first end 220. In some embodiments, the flange 404 can cover the aperture 410 and fluidly seal the fluid outlet 218 to the second sheet 204, preventing fluid communication with the ambient environment between the flange 404 and the second sheet 204. The one or more lumens 402 can be in fluid communication with the aperture 410 of the second sheet 204 through the flange 404. In some embodiments, the fluid outlet 218 can have a conduit port 406. The conduit port 406 can be coupled to a fluid conductor or other device to provide fluid communication between the lumen 402 and the negative-pressure source 102. In some embodiments, a hydrophobic fdter 408 can be disposed in the fluid outlet 218. The fluid inlet 216 may have a similar construction.

[0086] The hydrophobic filter 408 can be coupled to the flange 404 or disposed over the aperture in the second sheet 204. The hydrophobic filter 408 can limit or prevent flow of liquids out of the second chamber 214 through the fluid outlet 218. In some embodiments, a one-way valve, such as a duckbill valve can be fluidly coupled to the fluid outlet 218. For example, the one-way valve can be positioned to permit fluid flow from the container 106 toward the negative-pressure source 102 and prevent fluid flow from the negative-pressure source 102 into the container 106. In some embodiments, the one-way valve could be coupled to the conduit port 406, disposed between the conduit port 406 and the fluid conductor, or disposed in the fluid conductor.

[0087] Figure 5 is a detail view of the bridge 224, illustrating additional details that may be associated with some embodiments. In some embodiments, the weir 210 can be a partial baffle. For example, the weir 210 may terminate prior to reaching the second end 222 of the container 106, leaving an aperture or gap 502 between the end of the weir 210 and the weld 206. The bridge 224 can be coupled to the weir 210, the first sheet 202 and the second sheet 204 to substantially fill the gap 502. For example, the bridge 224 is coupled to the weir 210, the first sheet 202, and the second sheet 204 so that fluid communication between the first chamber 212 and the second chamber 214 is only possible through the bridge 224. In some embodiments, the bridge 224 can be a fluid distributor and can comprise a felted or non-felted foam. For example, the bridge 224 can be an open-cell reticulated foam or a felted foam as previously described. In other embodiments, the bridge 224 can be formed from a V.A.C. VERAFLO™ Dressing, available from Kinetic Concepts, Inc., of San Antonio, Texas that is felted to have a density three times its non-felted density. In some illustrative embodiments, the fluid distributor 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.

[0088] Referring to Figure 2, in operation, the negative-pressure source 102 can be fluidly coupled to the fluid outlet 218, and the dressing 104 can be fluidly coupled to the fluid inlet 216. Activation of the negative-pressure source 102 can draw fluid from the container 106 through the fluid outlet 218 and from the dressing 104 through the fluid inlet 216. As previously described, the weir 210 is disposed in the interior space 208 to create a tortuous pathway between the fluid inlet 216 and the fluid outlet 218. As fluid is drawn from the dressing 104 into the container 106, liquids from the tissue site may encounter the first foam pouch 226 and be drawn into the absorbent core 302 proximate to the fluid inlet 216. As the absorbent core 302 of the first foam pouch 226 becomes saturated proximate to the fluid inlet 216, the first manifold layer 304 and the second manifold layer 306 maintain open fluid pathways around the portions of the absorbent core 302 that are saturated. Fluid may flow to areas of the absorbent core 302 that are free of liquid or capable of absorbing more liquid. In some embodiments, the difference in density and hydrophobicity allows the second manifold layer 306 to urge fluid toward the absorbent core 302 through the first manifold layer 304 while the negative- pressure source 102 maintains a general flow of fluid through the container 106 from the fluid inlet 216 across the bridge 224 to the fluid outlet 218. The absorbent core 302 enclosed by the first manifold layer 304 and the second manifold layer 306 retains liquids, while the first manifold layer 304 and the second manifold layer 306 maintains open pathways for fluid around the absorbent core 302 as the absorbent core 302 becomes saturated. As the absorbent core 302 of the first foam pouch 226 becomes saturated, liquids may be drawn across the bridge into the absorbent core 302 of the second foam pouch 228. The first manifold layer 304 and the second manifold layer 306 permit the container 106 to be used in any orientation. The first manifold layer 304 and the second manifold layer 360 can manifold fluid and direct liquid into the absorbent core 302, maintaining open fluid pathways from the fluid inlet 216 to the fluid outlet 218.

[0089] Figure 6A is a schematic diagram illustrating additional details that may be associated with another example embodiment of the container 106 of Figure 1. In some embodiments, a sensing bypass 602 can be disposed in the container 106. The sensing bypass 602 can fluidly couple the secondary lumens of the fluid inlet 216 and the fluid outlet 218 through the interior space 208. The sensing bypass 602 can be a fluid conductor, such as a tube or conduit. In other embodiments, the sensing bypass 602 can be formed by coupling a portion of the first sheet 202 and the second sheet 204 to create a chamber or pathway that is fluidly isolated from the first chamber 212 and the second chamber 214. In some embodiments, the sensing bypass 602 can provide a direct pressure-sensing pathway between the fluid inlet 216 and the fluid outlet 218.

[0090] Figure 6B is a detail view of the fluid inlet 216 illustrating additional details that may be associated with some embodiments. The fluid inlet 216 can be a fluid port or other device configured to provide fluid communication across the first sheet 202. In some embodiments, the fluid inlet 216 may have a primary lumen 604 and a secondary lumen 606 configured to provide a fluid path through the fluid inlet 216. The fluid inlet 216 can include a flange 608. The flange 608 can be coupled to the first sheet 202. The first sheet 202 can have an aperture 610 proximate to the first end 220. In some embodiments, the flange 608 can cover the aperture 610 and fluidly seal the fluid inlet 216 to the first sheet 202, preventing fluid communication with the ambient environment between the flange 608 and the first sheet 202. The primary lumen 604 can be in fluid communication with the aperture 610 of the first sheet 202 through the flange 608. The secondary lumen 606 can be in fluid communication with the sensing bypass 602. In some embodiments, the fluid inlet 216 can have a conduit port 612. The conduit port 612 can be coupled to a fluid conductor or other device to provide fluid communication between the primary lumen 604 and the dressing 104. The conduit port 612 can also provide fluid communication with the secondary lumen 606 and the dressing 104. In some embodiments, the primary lumen 604 and the secondary lumen 606 are fluidly isolated from each other. The fluid outlet 218 may have a similar construction. The primary lumens of the fluid inlet 216 and the fluid outlet 218 may carry fluids, including liquids from the tissue site to and from the container 106. The secondary lumens of the fluid inlet 216 and the fluid outlet 218 can be sensing lumens configured to communicate a pressure at the tissue site to a device, such as the controller 108, for further processing.

[0091] Figure 7 is a schematic diagram illustrating additional details that may be associated with another example embodiment of the container 106 of Figure 1. The container 106 of Figure 7 can include the first sheet 202, the second sheet 204, and the weld 206 forming a chamber, such as the interior space 208. The fluid inlet 216 can be coupled to the first end 220, and the fluid outlet 218 can be coupled to the second end 222. In some embodiments, fluid distributors, such as a plurality of foam layers 702 can be disposed in the interior space 208. A fluid storage media, such as a plurality of absorptive layers 704, can also be disposed in the interior space 208. In some embodiments, each absorptive layer 704 can be positioned adjacent to a respective foam layer 702.

[0092] Each foam layer 702 may be a fluid distributor. For example, each foam layer 702 may be formed from an open-cell reticulated foam. In some embodiments, each foam layer 702 can be formed from a felted open-cell reticulated foam, such as a V.A.C. VERAFLO™ Dressing, available from Kinetic Concepts, Inc., of San Antonio, Texas that is felted to have a density three times its non- felted density. In some embodiments, the density between each foam layer 702 can vary. For example, foam layers 702 proximate to the first end 220 of the container 106 can have a first density and foam layers 702 proximate to the second end 222 of the container 106 can have a second density. In some embodiments, the density of the foam layers 702 proximate to the first end 220 can be greater than the density of the foam layers 702 proximate to the second end 222. In other embodiments, the density of the foam layers 702 proximate to the second end 222 can be greater than the density of the foam layers 702 proximate to the first end 220. In still other embodiments, the density of each foam layer 202 can be selected to encourage fluid flow through the container 106 in a preferred flow path.

[0093] Each foam layer 702 may extend from the first sheet 202 to the second sheet 204. In some embodiments, each foam layer 702 is coupled to the first sheet 202 and the second sheet 204 to prevent fluid communication around the foam layers 702. In some embodiments, each foam layer 702 can be adhered, welded, bonded, or otherwise coupled to the first sheet 202 and the second sheet 204. For example, in some embodiments, surfaces of each foam layer 702 adjacent to the first sheet 202 and the second sheet 204 can be coated in an adhesive, such as an acrylic adhesive. The adhesive can be configured to adhere the foam layer 704 to the durable polymer of the first sheet 202 and the second sheet 204. The adhesive can prevent fluid flow between the foam layer 704 and the first sheet 202 and the second sheet 204, encouraging fluid flow through the foam layer 704. Each foam layer 702 may have a thickness 708. In some embodiments, the thickness 708 may be between about 3 mm and about 40 mm and, preferably, about 6.35 mm or about 6.5 mm.

[0094] Each absorptive layer 704 can be formed from a fluid storage media. In some embodiments, the absorptive layers 704 can be formed from a superabsorbent polymer or absorbent pellets. For example, the absorptive layers 704 can be formed from a KERRAMAX CARE™ Super- Absorbent Dressing material available from Kinetic Concepts, Inc. of San Antonio, Texas. Each absorptive layer 704 may extend from the first sheet 202 to the second sheet 204. In some embodiments, each absorptive layer 704 is coupled to the first sheet 202 and the second sheet 204 to prevent fluid communication around the foam layers 702. In some embodiments, each absorptive layer 704 can be adhered, welded, bonded, or otherwise coupled to the first sheet 202 and the second sheet 204. For example, in some embodiments, surfaces of each absorptive layer 704 adjacent to the first sheet 202 and the second sheet 204 can be coated in an adhesive, such as an acrylic adhesive. The adhesive can be configured to adhere the absorptive layer 704 to the durable polymer of the first sheet 202 and the second sheet 204. The adhesive can prevent fluid flow between the absorptive layer 704 and the first sheet 202 and the second sheet 204, encouraging fluid flow through the absorptive layer 704. Each absorptive layer 704 may have a thickness 710. In some embodiments, the thickness 710 of the absorptive layer 704 can be formed from one or more layers of KERRAMAX CARE™ Super- Absorbent Dressing material having a thickness between about 0.5 mm and about 4.0 mm and preferably about 1.0 mm. For example, the absorptive layer 704 can comprise four sheets of KERRAMAX CARE™ Super- Absorbent Dressing material each having a thickness of about 1.0 mm, and the resulting thickness 710 can be about 4.0 mm.

[0095] Each absorptive layer 704 can be disposed adjacent to at least one foam layer 702. In some embodiments, each foam layer 702 may have an absorptive layer 704 positioned adjacent to each side of the foam layer 702. For example, as fluid travels from the fluid inlet 216 to the fluid outlet 218, fluid will encounter an absorptive layer 704 followed by a foam layer 702, followed by another absorptive layer 704, followed by another foam layer 702 until the fluid reaches the fluid outlet 218. In some embodiments, the container 106 can include ten foam layers 702 and eleven absorptive layers 704. In other embodiments, the container 106 can include more or fewer foam layers 702 and absorptive layers 704.

[0096] In some embodiments, each absorptive layer 704 can include a plurality of perforations 706. Each perforation 706 can be an opening extending through the absorptive layer 704 from a first side to a second side. Generally, each perforation 706 can be sized to be large enough to remain free of absorbent if the absorbent is fully saturated while being small enough to allow absorption of liquid into the absorptive layer 704 to occur. Each perforation 706 may be substantially free of the fluid storage media. In some embodiments, the perforations 706 may have an average effective diameter between about 3.0 mm and about 5.0 mm and, preferably, about 4.0 mm. The perforations 706 can allow for fluid flow across the absorptive layer 704, for example, if the absorptive layer 704 becomes saturated.

[0097] In some embodiments, perforations 706 in successive absorptive layers 704 may be offset from each other. For example, a perforation 706 in a first absorptive layer 704 can be offset from a perforation 706 in a second absorptive layer 704 that is immediately downstream of the first absorptive layer 706. Perimeters of perforations 706 in subsequent absorptive layers 704 may have no overlap. In other embodiments, perimeters of perforations 706 in subsequent absorptive layers 704 may have some overlap provided the fluid path of least resistance to fluid flow from the first end 220 to the second end 222 passes through at least a portion of each absorptive layer 704.

[0098] In operation, the negative-pressure source 102 can be fluidly coupled to the fluid outlet 218, and the dressing 104 can be fluidly coupled to the fluid inlet 216. Activation of the negative- pressure source 102 can draw fluid from the container 106 through the fluid outlet 218 and from the dressing 104 through the fluid inlet 216. As fluid is drawn from the dressing 104 into the container 106, liquids from the tissue site may encounter the absorptive layer 704 proximate to the fluid inlet 216 and be drawn into the absorptive layer 704. As the absorptive layer 704 becomes saturated proximate to the fluid inlet 216, fluid may continue to flow across the absorptive layer 704 through the perforations 706. As fluid enters the foam layer 702 adjacent to the saturated absorptive layer 704, the foam layer 702 maintains open fluid pathways that distribute the fluid across the subsequent absorptive layer 704. The process repeats serially from the fluid inlet 216 to the fluid outlet 218 while the negative-pressure source 102 maintains a general flow of fluid through the container from the fluid inlet 216 to the fluid outlet 218 through the foam layers 702 and the perforations 706. The foam layers 702 and the perforations 706 permit the container 106 to be used in any orientation. The foam layers 702 and the perforations 706 can manifold fluid and direct liquid into the absorptive layer 704, maintaining open fluid pathways from the fluid inlet 216 to the fluid outlet 218.

[0099] Figure 8 is a schematic diagram illustrating additional details that may be associated with some example embodiments of the container 106 of Figure 1. In some embodiments, the container 106 can include the sensing bypass 602. The sensing bypass 602 can fluidly couple the secondary lumens of the fluid inlet 216 and the fluid outlet 218 through the interior space 208. The sensing bypass 602 can be a fluid conductor, such as a tube or conduit. In other embodiments, the sensing bypass 602 can be formed by coupling a portion of the first sheet 202 and the second sheet 204 to create a chamber or pathway that is fluidly isolated from the interior space 208. In some embodiments, the sensing bypass 602 can provide a direct pressure -sensing pathway between the negative-pressure source 102 and the dressing 104.

[00100] Figure 9 is a schematic diagram illustrating additional details that may be associated with another example embodiment of the container 106 of Figure 1. The container 106 of Figure 9 can include the first sheet 202, the second sheet 204, and the weld 206 forming a chamber, such as the interior space 208. The fluid inlet 216 can be coupled to the first sheet 202 at the first end 220, and the fluid outlet 218 can be coupled to the second sheet 204 at the second end 222. In some embodiments, a fluid distributor, such as a foam block 902, can be disposed in the interior space 208. A plurality of foam chambers 904 can be disposed in the foam block 902. A fluid storage apparatus 906 can be disposed in each foam chamber 904.

[00101] The foam block 902 is a fluid distributor. In some embodiments, the foam block 902 can be formed from an open-cell reticulated foam. In some embodiments, the foam block 902 can be formed from a felted open-cell reticulated foam. For example, the foam block 902 can be formed from an open-cell reticulated foam having a firmness factor of three or a density three times the density of the same open-cell reticulated foam that is non-felted. In some embodiments, the foam block 902 can substantially fill the interior space 208. For example, the foam block 902 can fill between 50% and 100% of the volume of the interior space 208.

[00102] A fluid storage chamber, such as the plurality of foam chambers 904, can be regions of the foam block 902 that are free from foam. For example, portions of the foam block 902 can be cut away, dissolved, or otherwise removed to form the foam chambers 904. Each foam chamber 904 can be surrounded on at least four sides by the foam block 902. Preferably, adjacent foam chambers 904 may be spaced apart from each other. For example, each foam chamber 904 can be separated from adjacent foam chambers 904 by a distance between about 3 mm and about 40 mm and, preferably, about 6.35 mm or about 6.5 mm. In some embodiments, the foam block 902 may have one foam chamber 904. In other embodiments, the foam block 902 may have a plurality of foam chambers 904.

[00103] Figure 10 is a detail view of a portion of the container 106 of Figure 9 illustrating additional details that may be associated with some embodiments. Each fluid storage apparatus 906 can have an absorptive core 1002 and an impermeable layer 1004. The absorptive core 1002 can have an upstream side 1006 and a downstream side 1008. In some embodiments, the absorptive core 1002 can be formed from a fluid storage media, such as an SAP or absorbent pellets formed from an SAP. In some embodiments, the absorptive core 1002 can have a thickness between about 0.5 mm and about 4.0 mm and preferably about 1.0 mm.

[00104] The impermeable layer 1004 can be coupled to the absorptive core 1002. Preferably, the impermeable layer 1004 is coupled to the downstream side 1008 of the absorptive core 1002. The impermeable layer 1004 can comprise a film, coating, or other substance configured to prevent the flow of fluid across the impermeable layer 1004. In some embodiments, the impermeable layer 1004 may be, for example, an elastomeric film or membrane that can provide a seal over the downstream side 1008 of the absorptive core 1002. The impermeable layer 1004 may have a high moisture-vapor transmission rate (MVTR) in some applications. For example, the MVTR may be at least 300 g/m² per twenty-four hours in some embodiments. In some example embodiments, the impermeable layer 1004 may be a polymer drape, such as a polyurethane film, that is permeable to water vapor but impermeable to liquid. Such drapes typically have a thickness in the range of about 25 microns to about 50 microns. For permeable materials, the permeability generally should be low enough to inhibit fluid flow across the impermeable layer 1004.

[00105] The impermeable layer 1004 may comprise, for example, one or more of the following materials: hydrophilic polyurethane; cellulosics; hydrophilic polyamides; polyvinyl alcohol; polyvinyl pyrrolidone; hydrophilic acrylics; hydrophilic silicone elastomers; an INSPIRE 2301 material from Coveris Advanced Coatings of Wrexham, United Kingdom having, for example, an MVTR (inverted cup technique) of 14400 g/m²/24 hours and a thickness of about 30 microns; a thin, uncoated polymer drape; natural rubbers; polyisoprene; styrene butadiene rubber; chloroprene rubber; polybutadiene; nitrile rubber; butyl rubber; ethylene propylene rubber; ethylene propylene diene monomer; chlorosulfonated polyethylene; polysulfide rubber; polyurethane (PU); EVA film; co-polyester; silicones; a silicone drape; a 3M Tegaderm® drape; a polyurethane (PU) drape such as one available from Avery Dennison Corporation of Glendale, California; polyether block polyamide copolymer (PEBAX), for example, from Arkema, France; INSPIRE 2327; or other appropriate material.

[00106] An attachment device may be used to attach the impermeable layer 1004 to downstream side 1008 of the absorptive core 1002. The attachment device may take many forms. For example, an attachment device may be a medically-acceptable, pressure-sensitive adhesive configured to bond the impermeable layer 1004 to epidermis around a tissue site. In some embodiments, for example, some or all of the impermeable layer 1004 may be coated with an adhesive, such as an acrylic adhesive, which may have a coating weight between about 25 grams to about 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.

[00107] A volume of each foam chamber 904 can be substantially equal to a total volume of the absorptive core 1002 and the impermeable layer 1004. In some embodiments, the volume of each foam chamber 904 can change as the absorptive layer 1002 absorbs liquid. For example, as the absorptive core 1002 absorbs liquid form the tissue site, the absorptive core 1002 can expand, increasing the volume of the absorptive core 1002. In response, the foam chamber 904 can expand to accommodate the increased volume of the absorptive core 1002.

[00108] In operation, the negative-pressure source 102 can be fluidly coupled to the fluid outlet 218, and the dressing 104 can be fluidly coupled to the fluid inlet 216. Activation of the negative- pressure source 102 can draw fluid from the container 106 through the fluid outlet 218 and from the dressing 104 through the fluid inlet 216. As fluid is drawn from the dressing 104 into the container 106, liquids from the tissue site may encounter a fluid storage apparatus 906 proximate to the fluid inlet 216. The liquids can be absorbed and retained by the absorptive core 1002 of the fluid storage apparatus 906. As the absorptive core 1002 of the fluid storage apparatus 906 proximate to the fluid inlet 216 become saturated, the foam block 902 maintains open fluid pathways around the portions of the absorptive core 1002 that are saturated. Fluid may flow to areas of the absorptive core 1002 that are free of liquid or capable of absorbing more liquid. The impermeable layer 1004 can limit the flow of fluids across the fluid storage apparatus 906, encouraging flow through the overlying absorptive core 1002 and through the foam block 902 surrounding the fluid storage apparatus 906. The process can repeat serially in subsequent fluid storage apparatuses 906 from the fluid inlet 216 to the fluid outlet 218 while the negative -pressure source 102 maintains a general flow of fluid through the container 106 from the fluid inlet 216 to the fluid outlet 218 through the foam block 902.

[00109] The construction of the foam block 902 having multiple fluid storage apparatuses 906 provides multiple paths for fluid to travel through the container 106, allowing the container 106 to be stored in several orientations without disrupting transmission of negative pressure as the container 106 fdls with liquid. The impermeable layer 1004 can promote efficient liquid absorption, directing the fluid to fill each absorptive core 1002 serially from the fluid inlet 216 of the container 106 to the fluid outlet 218.

[00110] The containers described herein provide flexible fluid pouches for the storage and management of effluent from the tissue site. The containers can be deployed between the dressing and the negative-pressure source during negative pressure therapy. The containers have an inlet port to accept liquid and an outlet port to allow fluid flow while blocking the flow of liquids. The containers can include a super-absorbent material encased or enclosed in reticulated foam to maximize liquid retention, while effectively manifolding pressure between the dressing and the negative-pressure source. The containers also provide for fluid storage and maintenance while the container is disposed in multiple orientations. In some embodiments, selective layers of the foam and/or absorbent material can be joined to promote fluid flow in a particular direction.

[00111] The systems, apparatuses, and methods described herein may provide significant advantages. For example, the container 106 can connect between a wound dressing and a negative- pressure therapy system to collect wound exudate, while maintaining an open pathway to manifold negative pressure between the dressing and the negative -pressure source. The container 106 provides a simple, compact method of storing and managing tissue site effluent during negative-pressure therapy. The container 106 can be deployed with disposable negative-pressure therapy systems, increasing the volume of fluid that can be managed by disposable negative-pressure therapy systems. The increased volume of liquid that can be managed can expand the size and complexity of tissue sites that can be managed by a disposable negative-pressure therapy system. For example, the container 106 can fit more easily into carry pouches. The container 106 can readily conform to a carrying case, without any hard points. An empty container 106 can have a smaller volume and occupy less space than a rigid container, while being no larger than a rigid container for staring an equal amount of liquid at full volume. The smaller empty volume also permits the container 106 to be more easily stored, packaged, and disposed of. Furthermore, the reticulated foam surrounding an absorbent material can provide a plurality of flow paths for fluid within the pouch, allowing the container to be stored in several orientations without disrupting transmission of negative pressure as the container fills with fluid. The inclusion of multiple chambers separated by weirs can also promote efficient fluid absorption, ensuring the absorptive layers fill serially from the inlet side of the pouch to the outlet. The container 106 may also use materials that offer simplified manufacturing processes and lower cost relative to traditional hard canister designs. [00112] 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 106, or both may be eliminated or separated from other components for manufacture or sale. In other example configurations, the controller 108 may also be manufactured, configured, assembled, or sold independently of other components. [00113] 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 first pouch wall; a second pouch wall having an exterior edge of the second pouch wall coupled to an exterior edge of the first pouch wall to form a chamber; a first port fluidly coupled to the chamber; a second port fluidly coupled to the chamber; a fluid storage media disposed in the chamber; and a fluid distributor disposed adjacent to the fluid storage media, the fluid distributor providing a plurality of tortuous pathways between the first port and the second port.

2. The fluid storage pouch of claim 1, further comprising a sensing bypass disposed in the chamber and fluidly isolated from the chamber.

3. The fluid storage pouch of claim 1, wherein the first pouch wall and the second pouch wall comprise a low moisture-vapor transmission rate (MVTR) durable polymer.

4. The fluid storage pouch of claim 1, further comprising a hydrophobic filter disposed in the second port.

5. The fluid storage pouch of claim 1, wherein the fluid storage media is formed from a superabsorbent polymer.

6. The fluid storage pouch of claim 1, wherein the fluid storage media comprises a plurality of absorbent pellets.

7. The fluid storage pouch of claim 1, wherein the fluid distributor comprises an open-cell reticulated foam.

8. The fluid storage pouch of claim 1, wherein the fluid distributor comprises a felted foam.

9. The fluid storage pouch of claim 8, wherein the felted foam has a firmness factor of three.

10. The fluid storage pouch of any of claims 1-9, wherein: the first port is fluidly coupled to a first end of the chamber; the second port is fluidly coupled to a second end of the chamber; the fluid distributor comprises a plurality of foam layers disposed in the chamber; and the fluid storage media comprises a plurality of absorptive layers disposed in the chamber, each absorptive layer positioned adjacent to a respective foam layer.

11. The fluid storage pouch of claim 10, further comprising a plurality of fenestrations disposed in each absorptive layer.

12. The fluid storage pouch of claim 11, wherein the fenestrations in absorptive layers on opposing sides of a foam layer of the plurality of foam layers are offset from each other.

13. The fluid storage pouch of any of claims 1-9, wherein: the first port is fluidly coupled to a first end of the chamber; the second port is fluidly coupled to a second end of the chamber; the fluid distributor comprises a foam block disposed in the chamber, the foam block having a plurality of foam chambers; the fluid storage media comprises a plurality of absorptive layers, each absorptive layer disposed in a respective foam chamber; and a plurality of impermeable layers, each impermeable layer disposed on a downstream side of a respective absorptive layer.

14. The fluid storage pouch of any of claims 1-9, wherein: the fluid storage pouch further comprises a weir disposed in the chamber and separating the chamber into a first storage area and a second storage area; the first port is fluidly coupled to the first storage area; the second port is fluidly coupled to the second storage area; the fluid distributor comprises: a first fluid distributor pouch disposed in the first storage area; and a second fluid distributor pouch disposed in the second storage area.

15. The fluid storage pouch of claim 14, wherein each of the first fluid distributor pouch and the second fluid distributor pouch comprises: an absorbent core; and a foam layer surrounding the absorbent core.

16. The fluid storage pouch of claim 15, wherein the foam layer comprises: a first foam layer having a first density positioned adjacent to the absorbent core; and a second foam layer having a second density positioned adjacent to the first foam layer, the second density being greater than the first density.

17. The fluid storage pouch of claim 16, wherein the first foam layer comprises an open-cell reticulated foam.

18. The fluid storage pouch of claim 17, wherein the second foam layer comprises a felted foam.

19. The fluid storage pouch of claim 18, wherein the felted foam has a firmness factor of three.

20. The fluid storage pouch of claim 14, further comprising a bridge fluidly coupling the first storage area and the second storage area across the weir.

21. The fluid storage pouch of claim 20, wherein the bridge comprises fluid distributor material.

22. The fluid storage pouch of claim 20, wherein the bridge is coupled to the weir, the first pouch wall, and the second pouch wall.

23. The fluid storage pouch of claim 20, wherein the first port and the second port are disposed on a first end of the fluid storage pouch and the bridge is disposed on a second end of the fluid storage pouch opposite the first end.

24. The fluid storage pouch of claim 14, wherein the weir comprises a portion of the first pouch wall coupled to the second pouch wall.

25. The fluid storage pouch of claim 14, wherein the weir is positioned between the first port and the second port.

26. A fluid storage pouch comprising: a first film layer; a second film layer having a periphery coupled to a periphery of the first film layer to form a chamber; a weir disposed in the chamber and separating the chamber into a first storage area and a second storage area; a fluid inlet fluidly coupled to the first storage area; a fluid outlet fluidly coupled to the second storage area; a first foam pouch disposed in the first storage area; and a second foam pouch disposed in the second storage area.

27. The fluid storage pouch of claim 26, wherein each of the first foam pouch and the second foam pouch comprises: an absorbent core; and a foam layer surrounding the absorbent core.

28. The fluid storage pouch of claim 27, wherein the absorbent core comprises a superabsorbent polymer.

29. The fluid storage pouch of claim 27, wherein the absorbent core comprises a plurality of absorbent pellets.

30. The fluid storage pouch of claim 27, wherein the foam layer comprises: a first foam layer having a first density positioned adjacent to the absorbent core; and a second foam layer having a second density positioned adjacent to the first foam layer, the second density being greater than the first density.

31. The fluid storage pouch of claim 30, wherein the first foam layer comprises an open-cell reticulated foam.

32. The fluid storage pouch of claim 30, wherein the second foam layer comprises a felted foam.

33. The fluid storage pouch of claim 32, wherein the felted foam has a firmness factor of three.

34. The fluid storage pouch of claim 26, wherein the first film layer and the second film layer comprise a low moisture-vapor transmission rate (MVTR) durable polymer.

35. The fluid storage pouch of claim 26, further comprising a bridge fluidly coupling the first storage area and the second storage area across the weir.

36. The fluid storage pouch of claim 35, wherein the bridge comprises foam material.

37. The fluid storage pouch of claim 35, wherein the bridge is coupled to the weir, the first film layer, and the second film layer.

38. The fluid storage pouch of claim 35, wherein the fluid inlet and the fluid outlet are disposed on a first end of the fluid storage pouch and the bridge is disposed on a second end of the fluid storage pouch opposite the first end.

39. The fluid storage pouch of claim 26, wherein the weir comprises a portion of the first film layer coupled to the second film layer.

40. The fluid storage pouch of claim 26, further comprising a hydrophobic filter disposed in the fluid outlet.

41. The fluid storage pouch of claim 26, wherein the weir is positioned between the fluid inlet and the fluid outlet.

42. The fluid storage pouch of claim 26, further comprising a sensing bypass disposed in the chamber and fluidly isolated from the first storage area and the second storage area.

43. A fluid storage pouch comprising: a first film layer; a second film layer having a periphery coupled to a periphery of the first film layer to form a chamber; a fluid inlet fluidly coupled to a first end of the chamber; a fluid outlet fluidly coupled to a second end of the chamber; a plurality of foam layers disposed in the chamber; and a plurality of absorptive layers disposed in the chamber, each absorptive layer positioned adjacent to a respective foam layer.

44. The fluid storage pouch of claim 43, further comprising a plurality of perforations disposed in each absorptive layer.

45. The fluid storage pouch of claim 44, wherein the perforations in absorptive layers on opposing sides of a respective foam layer are offset from each other.

46. The fluid storage pouch of claim 43, further comprising a sensing bypass disposed in the chamber and fluidly isolated from the chamber.

47. The fluid storage pouch of claim 43, wherein the first film layer and the second film layer comprise a low moisture-vapor transmission rate (MVTR) durable polymer.

48. The fluid storage pouch of claim 43, wherein the absorptive layers are formed from a superabsorbent polymer.

49. The fluid storage pouch of claim 43, wherein each absorptive layer of the plurality of absorptive layers comprises a plurality of absorbent pellets.

50. A fluid storage pouch comprising: a first film layer; a second film layer having a periphery coupled to a periphery of the first film layer to form a chamber; a fluid inlet fluidly coupled to a first end of the chamber; a fluid outlet fluidly coupled to a second end of the chamber; a foam block disposed in the chamber, the foam block having a plurality of foam chambers; a plurality of absorptive layers, each absorptive layer disposed in a respective foam chamber; and a plurality of impermeable layers, each impermeable layer disposed on a downstream side of a respective absorptive layer.

51. The fluid storage pouch of claim 50, wherein the foam block comprises an open-cell reticulated foam.

52. The fluid storage pouch of claim 50, wherein the first film layer and the second film layer comprise a low moisture-vapor transmission rate (MVTR) durable polymer.

53. The fluid storage pouch of claim 50, wherein the foam block comprises a felted foam.

54. The fluid storage pouch of claim 50, wherein the absorptive layers comprise a superabsorbent polymer.

55. The fluid storage pouch of claim 50, wherein the absorptive layers comprise a plurality of absorbent pellets.

56. The systems, methods, and apparatuses as described herein.