Patent Description:
The applications of this phenomenon are numerous, but have proven particularly advantageous for treating wounds. Regardless of the etiology of a wound, whether trauma, surgery, or another cause, proper care of a wound is important to the outcome. Treatment of wounds or other tissue with reduced pressure may be commonly referred to as "negative-pressure therapy," but is also known by other names, including "negative-pressure wound therapy," "reduced-pressure therapy," "vacuum therapy," and "vacuum-assisted closure," for example.

While the clinical benefits of negative-pressure therapy are widely known, the cost and complexity of negative-pressure therapy can be a limiting factor in its application, and the development and operation of negative-pressure systems, components, and processes continues to present significant challenges to manufacturers, healthcare providers, and patients.

<CIT> discloses a dressing for treating a tissue site which may include a base layer, a sealing member, a first and a second wicking layer, and an absorbent layer. The base layer may have a plurality of apertures and may be adapted to cover the tissue site. The sealing member and the base layer may define an enclosure. The first and the second wicking layer may each be disposed in the enclosure with the absorbent layer positioned between the first and the second wicking layer.

<CIT> discloses a negative pressure wound dressing for use with breast incisions. The wound dressing includes a drape layer, a manifold layer, a base layer, and a reduced pressure interface. The drape layer has a first surface and a second, wound-facing, surface. The drape layer is substantially impermeable to liquid and substantially permeable to vapor. The manifold layer has a first surface and a second, wound-facing surface. The manifold layer has a perimeter defined by a first convex curved side surface defining a first lobe, a second convex curved side surface defining a second lobe, and a connecting portion between the first lobe and the second lobe. The base layer is configured to: (i) couple the drape layer to the manifold layer, and (ii) the dressing to a patient's tissue. The reduced pressure interface is integrated with the drape layer.

<CIT> discloses a reduced pressure treatment system which includes a reduced pressure source and a reduced pressure dressing. The dressing includes an interface layer adapted to be positioned at a tissue site and an absorbent layer in fluid communication with the interface layer to absorb liquid from at least one of the interface layer and the tissue site. A diverter layer is positioned adjacent the absorbent layer, and the diverter layer includes a plurality of apertures in fluid communication with the absorbent layer to distribute a reduced pressure to the absorbent layer. A cover is positioned over the diverter layer to maintain the reduced pressure at the tissue site.

<CIT> disclose a dressings for treating a linear wound, such as an incision, on a patient. The dressings include a sealing ring that helps form a fluid seal around the linear wound. In one instance, a sealing material is extruded around the linear wound to help form a seal.

Optional features of the invention are set out in the dependent claims.

The following description of example embodiments enables a person skilled in the art to make and use the subject matter set forth in the appended claims. Certain details already known in the art may be omitted. Therefore, the following detailed description is illustrative and non-limiting.

Referring to the drawings, <FIG> depicts an embodiment of a system <NUM> for treating a tissue site <NUM> of a patient. The tissue site <NUM> may extend through or otherwise involve an epidermis <NUM>, a dermis <NUM>, and a subcutaneous tissue <NUM>. In some embodiments, the tissue site <NUM> may be a sub-surface tissue site 104a as depicted in <FIG> that extends below the surface of the epidermis <NUM>. Further, in some embodiments, the tissue site <NUM> may be a surface tissue site 104b as depicted in <FIG> that predominantly resides on the surface of the epidermis <NUM>, such as, for example, an incision. The system <NUM> may provide therapy to, for example, the epidermis <NUM>, the dermis <NUM>, and the subcutaneous tissue <NUM>, regardless of the positioning of the system <NUM> or the type of tissue site. The system <NUM> may also be utilized without limitation at other tissue sites.

Further, the tissue site <NUM> may be the bodily tissue of any human, animal, or other organism, including bone tissue, adipose tissue, muscle tissue, dermal tissue, vascular tissue, connective tissue, cartilage, tendons, ligaments, or any other tissue. Treatment of tissue site <NUM> may include removal of fluids, e.g., exudate or ascites.

Continuing with <FIG>, the system <NUM> may include an optional tissue interface, such as an interface manifold <NUM>. Further, the system <NUM> may include a dressing <NUM>, and a reduced-pressure source <NUM>. The reduced-pressure source <NUM> may be a component of an optional therapy unit <NUM> as shown in <FIG>. In some embodiments, the reduced-pressure source <NUM> and the therapy unit <NUM> may be separate components. As indicated above, the interface manifold <NUM> is an optional component that may be omitted for different types of tissue sites or different types of therapy using reduced pressure, such as, for example, epithelialization, tissue closure, incision treatment, and others. If equipped, the interface manifold <NUM> may be adapted to be positioned proximate to or adjacent to the tissue site <NUM>, such as, for example, by cutting or otherwise shaping the interface manifold <NUM> in any suitable manner to fit the tissue site <NUM>. As described below, the interface manifold <NUM> may be adapted to be positioned in fluid communication with the tissue site <NUM> to distribute reduced pressure to the tissue site <NUM>. In some embodiments, the interface manifold <NUM> may be positioned in direct contact with the tissue site <NUM>. The tissue interface or the interface manifold <NUM> may be formed from any manifold material or flexible bolster material that provides a vacuum space, or treatment space, such as, for example, a porous and permeable foam or foam-like material, a member formed with pathways, a graft, or a gauze. As a more specific, non-limiting example, the interface manifold <NUM> may be a reticulated, open-cell polyurethane or polyether foam that allows good permeability of fluids while under a reduced pressure. One such foam material is the VAC® GranuFoam® material available from Kinetic Concepts, Inc. (KCI) of San Antonio, Texas. Any material or combination of materials may be used as a manifold material for the interface manifold <NUM> provided that the manifold material is operable to distribute or collect fluid. For example, herein the term manifold may refer to a substance or structure that is provided to assist in delivering fluids to or removing fluids from a tissue site through a plurality of pores, pathways, or flow channels. The plurality of pores, pathways, or flow channels may be interconnected to improve distribution of fluids provided to and removed from an area around the manifold. Examples of manifolds may include, without limitation, devices that have structural elements arranged to form flow channels, cellular foam, such as open-cell foam, porous tissue collections, and liquids, gels, and foams that include or cure to include flow channels.

A material with a higher or lower density than GranuFoam® material may be desirable for the interface manifold <NUM> depending on the application. Among the many possible materials, the following may be used: GranuFoam® material, Foamex® technical foam, a molded bed of nails structures, a patterned grid material such as those manufactured by Sercol Industrial Fabrics, 3D textiles such as those manufactured by Baltex of Derby, U. , a gauze, a flexible channel-containing member, a graft, etc. In some instances, ionic silver may be added to the interface manifold <NUM> by, for example, a micro bonding process. Other substances, such as anti-microbial agents, may be added to the interface manifold <NUM> as well.

In some embodiments, the interface manifold <NUM> may comprise a porous, hydrophobic material. The hydrophobic characteristics of the interface manifold <NUM> may prevent the interface manifold <NUM> from directly absorbing fluid, such as exudate, from the tissue site <NUM>, but allow the fluid to pass through.

Continuing with <FIG>, the dressing <NUM> may be adapted to provide reduced pressure from the reduced-pressure source <NUM> to the interface manifold <NUM>, and to store fluid extracted from the tissue site <NUM> through the interface manifold <NUM>. The dressing <NUM> may include a base layer <NUM>, an adhesive <NUM>, a sealing member <NUM>, a fluid management assembly <NUM>, and a conduit interface <NUM>. Components of the dressing <NUM> may be added or removed to suit a particular application.

Referring to <FIG>, the base layer <NUM> may have a periphery <NUM> surrounding a central portion <NUM>, and a plurality of apertures <NUM> disposed through the periphery <NUM> and the central portion <NUM>. The base layer <NUM> may also have corners <NUM> and edges <NUM>. The corners <NUM> and the edges <NUM> may be part of the periphery <NUM>. One of the edges <NUM> may meet another of the edges <NUM> to define one of the corners <NUM>. Further, the base layer <NUM> may have a border <NUM> substantially surrounding the central portion <NUM> and positioned between the central portion <NUM> and the periphery <NUM>. The border <NUM> may be free of the apertures <NUM>.

The central portion <NUM> of the base layer <NUM> may be configured to be positioned proximate to the tissue site <NUM>, and the periphery <NUM> of the base layer <NUM> may be configured to be positioned proximate to tissue surrounding the tissue site <NUM>. In some embodiments, the base layer <NUM> may cover the interface manifold <NUM> and tissue surrounding the tissue site <NUM> such that the central portion <NUM> of the base layer <NUM> is positioned adjacent to or proximate to the interface manifold <NUM>, and the periphery <NUM> of the base layer <NUM> is positioned adjacent to or proximate to tissue surrounding the tissue site <NUM>. In this manner, the periphery <NUM> of the base layer <NUM> may surround the interface manifold <NUM>. Further, the apertures <NUM> in the base layer <NUM> may be in fluid communication with the interface manifold <NUM> and tissue surrounding the tissue site <NUM>.

The apertures <NUM> in the base layer <NUM> may have any shape, such as, for example, circles, squares, stars, ovals, polygons, slits, complex curves, rectilinear shapes, triangles, or other shapes. The apertures <NUM> may be formed by cutting, by application of local RF energy, or other suitable techniques for forming an opening. As shown in <FIG>, each of the apertures <NUM> of the plurality of apertures <NUM> may be substantially circular in shape, having a diameter and an area. The area of each of the apertures <NUM> may refer to an open space or open area defining each of the apertures <NUM>. The diameter of each of the apertures <NUM> may define the area of each of the apertures <NUM>. For example, the area of one of the apertures <NUM> may be defined by multiplying the square of half the diameter of the aperture <NUM> by the value <NUM>. Thus, the following equation may define the area of one of the apertures <NUM>: Area = <NUM>*(diameter/<NUM>)^<NUM>. The area of the apertures <NUM> described in the illustrative embodiments herein may be substantially similar to the area in other embodiments (not shown) for the apertures <NUM> that may have non-circular shapes. The diameter of each of the apertures <NUM> may be substantially the same, or each of the diameters may vary depending, for example, on the position of the aperture <NUM> in the base layer <NUM>. For example, the diameter of the apertures <NUM> in the periphery <NUM> of the base layer <NUM> may be larger than the diameter of the apertures <NUM> in the central portion <NUM> of the base layer <NUM>. Further, the diameter of each of the apertures <NUM> may be about <NUM> millimeter to about <NUM> millimeters. In some embodiments, the diameter of each of the apertures <NUM> may be about <NUM> millimeter to about <NUM> millimeters. The apertures <NUM> may have a uniform pattern or may be randomly distributed on the base layer <NUM>. The size and configuration of the apertures <NUM> may be designed to control the adherence of the dressing <NUM> to the epidermis <NUM> as described below.

Referring to <FIG>, in some embodiments, the apertures <NUM> positioned in the periphery <NUM> may be apertures 160a and the apertures <NUM> positioned in the central portion <NUM> may be apertures 160c. The apertures 160a may have a diameter between about <NUM> millimeters to about <NUM> millimeters. The apertures 160c may have a diameter between about <NUM> millimeters to about <NUM> millimeters.

As shown in <FIG>, in some embodiments, the central portion <NUM> of the base layer <NUM> may be substantially oval in shape. The border <NUM> of the base layer <NUM> may substantially surround the central portion <NUM> and the apertures 160c in the central portion <NUM>. The periphery <NUM> of the base layer <NUM> may substantially surround the border <NUM> and the central portion <NUM>. Further, the periphery <NUM> may have a substantially oval exterior shape. Although <FIG> depict the central portion <NUM>, the border <NUM>, and the periphery <NUM> of the base layer <NUM> as having a substantially oval shape, these and other components of the base layer <NUM> may have other shapes to suit a particular application.

The base layer <NUM> may be a soft, pliable material suitable for providing a fluid seal with the tissue site <NUM> as described herein. For example, the base layer <NUM> may comprise a silicone, a silicone gel, a soft silicone, hydrocolloid, hydrogel, polyurethane gel, polyolefin gel, hydrogenated styrenic copolymer gels, a foamed gel, a soft closed cell foam such as polyurethanes and polyolefins coated with an adhesive described below, polyurethane, polyolefin, or hydrogenated styrenic copolymers. The base layer <NUM> may have a thickness between about <NUM> microns (µm) and about <NUM> microns (µm). In some embodiments, the base layer <NUM> has a stiffness between about <NUM> Shore OO and about <NUM> Shore OO. The base layer <NUM> may be comprised of hydrophobic or hydrophilic materials.

In some embodiments (not shown), the base layer <NUM> may be a hydrophobic-coated material. For example, the base layer <NUM> may be formed by coating a spaced material, such as, for example, woven, nonwoven, molded, or extruded mesh with a hydrophobic material. The hydrophobic material for the coating may be a soft silicone, for example. In this manner, the adhesive <NUM> may extend through openings in the spaced material analogous to the apertures <NUM> described below.

The adhesive <NUM> may be in fluid communication with the apertures <NUM> in at least the periphery <NUM> of the base layer <NUM>. In this manner, the adhesive <NUM> may be in fluid communication with the tissue surrounding the tissue site <NUM> through the apertures <NUM> in the base layer <NUM>. As described below and shown in <FIG>, the adhesive <NUM> may extend through or be pressed through the plurality of apertures <NUM> to contact the epidermis <NUM> for securing the dressing <NUM> to, for example, the tissue surrounding the tissue site <NUM>. The apertures <NUM> may provide sufficient contact of the adhesive <NUM> to the epidermis <NUM> to secure the dressing <NUM> about the tissue site <NUM>. However, the configuration of the apertures <NUM> and the adhesive <NUM>, described below, may permit release and repositioning of the dressing <NUM> about the tissue site <NUM>.

At least one of the apertures 160a in the periphery <NUM> of the base layer <NUM> may be positioned at the edges <NUM> of the periphery <NUM> and may have an interior cut open or exposed at the edges <NUM> that is in fluid communication in a lateral direction with the edges <NUM>. The lateral direction may refer to a direction toward the edges <NUM> and in the same plane as the base layer <NUM>. As shown in <FIG>, a plurality of the apertures 160a in the periphery <NUM> may be positioned proximate to or at the edges <NUM> and in fluid communication in a lateral direction with the edges <NUM>. The apertures 160a positioned proximate to or at the edges <NUM> may be spaced substantially equidistant around the periphery <NUM> as shown in <FIG>. However, in some embodiments, the spacing of the apertures 160a proximate to or at the edges <NUM> may be irregular. The adhesive <NUM> may be in fluid communication with the edges <NUM> through the apertures 160a being exposed at the edges <NUM>. In this manner, the apertures 160a at the edges <NUM> may permit the adhesive <NUM> to flow around the edges <NUM> for enhancing the adhesion of the edges <NUM> around the tissue site <NUM>, for example.

Continuing with <FIG>, any of the apertures <NUM> may be adjusted in size and number to maximize the surface area of the adhesive <NUM> in fluid communication through the apertures <NUM> for a particular application or geometry of the base layer <NUM>. For example, in some embodiments, apertures analogous to the apertures <NUM>, having varying size, may be positioned in the periphery <NUM> and at the border <NUM>. Similarly, apertures analogous to the apertures <NUM>, having varying size, may be positioned as in other locations of the base layer <NUM> that may have a complex geometry or shape.

The adhesive <NUM> may be a medically-acceptable adhesive. The adhesive <NUM> may also be flowable. For example, the adhesive <NUM> may comprise an acrylic adhesive, rubber adhesive, high-tack silicone adhesive, polyurethane, or other adhesive substance. In some embodiments, the adhesive <NUM> may be a pressure-sensitive adhesive comprising an acrylic adhesive with coating weight of <NUM> grams/m<NUM> (gsm) to <NUM> grams/m<NUM> (gsm). The adhesive <NUM> may be a layer having substantially the same shape as the periphery <NUM> of the base layer <NUM> as shown in <FIG>. In some embodiments, the layer of the adhesive <NUM> may be continuous or discontinuous. Discontinuities in the adhesive <NUM> may be provided by apertures (not shown) in the adhesive <NUM>. The apertures in the adhesive <NUM> may be formed after application of the adhesive <NUM> or by coating the adhesive <NUM> in patterns on a carrier layer, such as, for example, a side of the sealing member <NUM> adapted to face the epidermis <NUM>. Further, the apertures in the adhesive <NUM> may be sized to control the amount of the adhesive <NUM> extending through the apertures <NUM> in the base layer <NUM> to reach the epidermis <NUM>. The apertures in the adhesive <NUM> may also be sized to enhance the Moisture Vapor Transfer Rate (MVTR) of the dressing <NUM>, described further below.

Factors that may be utilized to control the adhesion strength of the dressing <NUM> may include the diameter and number of the apertures <NUM> in the base layer <NUM>, the thickness of the base layer <NUM>, the thickness and amount of the adhesive <NUM>, and the tackiness of the adhesive <NUM>. An increase in the amount of the adhesive <NUM> extending through the apertures <NUM> generally corresponds to an increase in the adhesion strength of the dressing <NUM>. A decrease in the thickness of the base layer <NUM> generally corresponds to an increase in the amount of adhesive <NUM> extending through the apertures <NUM>. Thus, the diameter and configuration of the apertures <NUM>, the thickness of the base layer <NUM>, and the amount and tackiness of the adhesive utilized may be varied to provide a desired adhesion strength for the dressing <NUM>. For example, the thickness of the base layer <NUM> may be about <NUM> microns, the adhesive layer <NUM> may have a thickness of about <NUM> microns and a tackiness of <NUM> grams per <NUM> centimeter wide strip, and the diameter of the apertures 160a in the base layer <NUM> may be about <NUM> millimeters.

In some embodiments, the tackiness of the adhesive <NUM> may vary in different locations of the base layer <NUM>. For example, in locations of the base layer <NUM> where the apertures <NUM> are comparatively large, such as the apertures 160a, the adhesive <NUM> may have a lower tackiness than other locations of the base layer <NUM> where the apertures <NUM> are smaller, such as the apertures 160c. In this manner, locations of the base layer <NUM> having larger apertures <NUM> and lower tackiness adhesive <NUM> may have an adhesion strength comparable to locations having smaller apertures <NUM> and higher tackiness adhesive <NUM>.

Clinical studies have shown that the configuration described herein for the base layer <NUM> and the adhesive <NUM> may reduce the occurrence of blistering, erythema, and leakage when in use. Such a configuration may provide, for example, increased patient comfort and increased durability of the dressing <NUM>.

Referring to the embodiment of <FIG>, a release liner <NUM> may be attached to or positioned adjacent to the base layer <NUM> to protect the adhesive <NUM> prior to application of the dressing <NUM> to the tissue site <NUM>. Prior to application of the dressing <NUM> to the tissue site <NUM>, the base layer <NUM> may be positioned between the sealing member <NUM> and the release liner <NUM>. Removal of the release liner <NUM> may expose the base layer <NUM> and the adhesive <NUM> for application of the dressing <NUM> to the tissue site <NUM>. The release liner <NUM> may also provide stiffness to assist with, for example, deployment of the dressing <NUM>. The release liner <NUM> may be, for example, a casting paper, a film, or polyethylene. Further, the release liner <NUM> may be a polyester material such as polyethylene terephthalate (PET), or similar polar semi-crystalline polymer. The use of a polar semi-crystalline polymer for the release liner <NUM> may substantially preclude wrinkling or other deformation of the dressing <NUM>. For example, the polar semi-crystalline polymer may be highly orientated and resistant to softening, swelling, or other deformation that may occur when brought into contact with components of the dressing <NUM>, or when subjected to temperature or environmental variations, or sterilization. Further, a release agent may be disposed on a side of the release liner <NUM> that is configured to contact the base layer <NUM>. For example, the release agent may be a silicone coating and may have a release factor suitable to facilitate removal of the release liner <NUM> by hand and without damaging or deforming the dressing <NUM>. In some embodiments, the release agent may be flourosilicone. In other embodiments, the release liner <NUM> may be uncoated or otherwise used without a release agent.

Continuing with <FIG>, the sealing member <NUM> has a periphery <NUM> and a central portion <NUM>. The sealing member <NUM> may additionally include a sealing member aperture <NUM> disposed through the sealing member <NUM>, as described below. The periphery <NUM> of the sealing member <NUM> may be positioned proximate to the periphery <NUM> of the base layer <NUM> such that the central portion <NUM> of the sealing member <NUM> and the central portion <NUM> of the base layer <NUM> define an enclosure <NUM>. The adhesive <NUM> may be positioned at least between the periphery <NUM> of the sealing member <NUM> and the periphery <NUM> of the base layer <NUM>. The sealing member <NUM> may cover the tissue site <NUM> and the interface manifold <NUM> to provide a fluid seal and a sealed space <NUM> between the tissue site <NUM> and the sealing member <NUM> of the dressing <NUM>. Further, the sealing member <NUM> may cover other tissue, such as a portion of the epidermis <NUM>, surrounding the tissue site <NUM> to provide the fluid seal between the sealing member <NUM> and the tissue site <NUM>. In some embodiments, a portion of the periphery <NUM> of the sealing member <NUM> may extend beyond the periphery <NUM> of the base layer <NUM> and into direct contact with tissue surrounding the tissue site <NUM>. In other embodiments, the periphery <NUM> of the sealing member <NUM>, for example, may be positioned in contact with tissue surrounding the tissue site <NUM> to provide the sealed space <NUM> without the base layer <NUM>. Thus, the adhesive <NUM> may also be positioned at least between the periphery <NUM> of the sealing member <NUM> and tissue, such as the epidermis <NUM>, surrounding the tissue site <NUM>. The adhesive <NUM> may be disposed on a surface of the sealing member <NUM> adapted to face the tissue site <NUM> and the base layer <NUM>.

The sealing member <NUM> may be formed from any material that allows for a fluid seal. A fluid seal is a seal adequate to maintain reduced pressure at a desired site given the particular reduced-pressure source or system involved. The sealing member <NUM> 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 <NUM> material from Expopack Advanced Coatings of Wrexham, United Kingdom having, for example, an MVTR (inverted cup technique) of <NUM>/m<NUM>/<NUM> hours and a thickness of about <NUM> 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 <NUM> Tegaderm® drape; a polyurethane (PU) drape such as one available from Avery Dennison Corporation of Pasadena, California; polyether block polyamide copolymer (PEBAX), for example, from Arkema, France; Expopack <NUM>; or other appropriate material.

The sealing member <NUM> may be vapor permeable and/or liquid impermeable, thereby allowing vapor and inhibiting liquids from exiting the sealed space <NUM> provided by the dressing <NUM>. In some embodiments, the sealing member <NUM> may be a flexible, breathable film, membrane, or sheet having a high MVTR of, for example, at least about <NUM>/m<NUM> per <NUM> hours. In other embodiments, a low or no vapor transfer drape might be used. The sealing member <NUM> may comprise a range of medically suitable films having a thickness up to about <NUM> microns (µm).

Referring to <FIG>, <FIG>, and <FIG>, the fluid management assembly <NUM> may be disposed in the enclosure <NUM> or positioned between the base layer <NUM> and the sealing member <NUM>. The fluid management assembly may include one or more wicking layers. In some embodiments, the fluid management assembly <NUM> may include a first wicking layer <NUM> and a second wicking layer <NUM>. Further, in some embodiments, the fluid management assembly <NUM> may include an absorbent material such as an absorbent layer <NUM>. Although the absorbent material is depicted in the form of a layer as the absorbent layer <NUM>, in some embodiments, the absorbent material may have a granular form or other suitable form. The absorbent layer <NUM> may be positioned in fluid communication between the first wicking layer <NUM> and the second wicking layer <NUM>. The first wicking layer <NUM> may have a grain structure adapted to wick fluid along a surface of the first wicking layer <NUM>. Similarly, the second wicking layer <NUM> may have a grain structure adapted to wick fluid along a surface of the second wicking layer <NUM>. For example, the first wicking layer <NUM> and the second wicking layer <NUM> may wick or otherwise transport fluid in a lateral direction along the surfaces of the first wicking layer <NUM> and the second wicking layer <NUM>, respectively. The surfaces of the first wicking layer <NUM> and the second wicking layer <NUM> may be normal relative to the thickness of each of the first wicking layer <NUM> and the second wicking layer <NUM>. The wicking of fluid along the first wicking layer <NUM> and the second wicking layer <NUM> may enhance the distribution of the fluid over a surface area of the absorbent layer <NUM> that may increase absorbent efficiency and resist fluid blockages. Fluid blockages may be caused by, for example, fluid pooling in a particular location in the absorbent layer <NUM> rather than being distributed more uniformly across the absorbent layer <NUM>. The laminate combination of the first wicking layer <NUM>, the second wicking layer <NUM>, and the absorbent layer <NUM> may be adapted as described herein to maintain an open structure, resistant to blockage, capable of maintaining fluid communication with, for example, the tissue site <NUM>.

In some embodiments, a peripheral portion <NUM> of the first wicking layer <NUM> may be coupled to a peripheral portion <NUM> of the second wicking layer <NUM> by a bond <NUM> to define a wicking layer enclosure <NUM> between the first wicking layer <NUM> and the second wicking layer <NUM>. In some exemplary embodiments, the wicking layer enclosure <NUM> may surround or otherwise encapsulate the absorbent layer <NUM> between the first wicking layer <NUM> and the second wicking layer <NUM>. In some embodiments, a single wicking layer may surround the absorbent layer <NUM> to form the wicking layer enclosure <NUM>.

Referring more specifically to <FIG> and <FIG>, the fluid management assembly <NUM> may include, without limitation, any number of wicking layers and absorbent layers as desired for treating a particular tissue site. In some embodiments, at least one wicking layer may surround the absorbent material. Further, in some embodiments, at least one intermediate wicking layer <NUM> may be disposed in fluid communication between the absorbent layer <NUM> and the second wicking layer <NUM>. In such an embodiment, the second wicking layer <NUM> may be positioned between the intermediate wicking layer <NUM> and the sealing member <NUM>. Further, including additional absorbent layers <NUM> may increase the absorbent mass of the fluid management assembly <NUM> and generally provide greater fluid capacity. However, for a given absorbent mass, multiple light coat-weight absorbent layers <NUM> may be utilized rather than a single heavy coat-weight absorbent layer <NUM> to provide a greater absorbent surface area for further enhancing the absorbent efficiency.

Each of the wicking layers <NUM>, <NUM>, and <NUM> may include a fluid distribution side <NUM> and a fluid acquisition side <NUM>. The fluid distribution side <NUM> may be positioned facing an opposite direction from the fluid acquisition side <NUM>. The fluid distribution side <NUM> may include longitudinal fibers <NUM> that define a grain structure. The longitudinal fibers <NUM> may be oriented substantially in a longitudinal direction along a length of the wicking layers <NUM>, <NUM>, and <NUM>. The fluid acquisition side <NUM> may include vertical fibers <NUM>, which are shown enlarged in <FIG> for illustrative purposes only. The vertical fibers <NUM> may be oriented substantially vertical or normal relative to the longitudinal fibers <NUM> and the length of wicking layers <NUM>, <NUM>, and <NUM>. In some embodiments, the fluid acquisition side <NUM> of both the second wicking layer <NUM> and the intermediate wicking layer <NUM> may be positioned facing the absorbent layer <NUM>, and the fluid acquisition side <NUM> of the first wicking layer <NUM> may be positioned facing away from the absorbent layer <NUM>. In such an embodiment, the fluid acquisition side <NUM> of the second wicking layer <NUM> may be positioned facing the fluid distribution side <NUM> of the intermediate wicking layer <NUM>, and the fluid distribution side <NUM> of the first wicking layer <NUM> may be positioned facing the absorbent layer <NUM>.

In some embodiments, the absorbent layer <NUM> may be a hydrophilic material adapted to absorb fluid from, for example, the tissue site <NUM>. Materials suitable for the absorbent layer <NUM> may include Luquafleece® material, Texsus FP2326, BASF 402C, Technical Absorbents <NUM> available from Technical Absorbents (www. techabsorbents. com), sodium polyacrylate super absorbers, cellulosics (carboxy methyl cellulose and salts such as sodium CMC), or alginates. Materials suitable for the first wicking layer <NUM> and the second wicking layer <NUM> may include any material having a grain structure capable of wicking fluid as described herein, such as, for example, Libeltex TDL2 80gsm.

The fluid management assembly <NUM> may be a pre-laminated structure manufactured at a single location or individual layers of material stacked upon one another as described above. Individual layers of the fluid management assembly <NUM> may be bonded or otherwise secured to one another without adversely affecting fluid management by, for example, utilizing a solvent or non-solvent adhesive, or by thermal welding. Further, the fluid management assembly <NUM> may be coupled to the border <NUM> of the base layer <NUM> in any suitable manner, such as, for example, by a weld or an adhesive. The border <NUM> being free of the apertures <NUM> as described above may provide a flexible barrier between the fluid management assembly <NUM> and the tissue site <NUM> for enhancing comfort.

In some embodiments, the enclosure <NUM> defined by the base layer <NUM> and the sealing member <NUM> may include an anti-microbial layer <NUM>. The addition of the anti-microbial layer <NUM> may reduce the probability of excessive bacterial growth within the dressing <NUM> to permit the dressing <NUM> to remain in place for an extended period. The anti-microbial layer <NUM> may be, for example, an additional layer included as a part of the fluid management assembly <NUM> as depicted in <FIG> and <FIG>, or a coating of an anti-microbial agent disposed in any suitable location within the dressing <NUM>. The anti-microbial layer <NUM> may be comprised of elemental silver or similar compound, for example. In some embodiments, the anti-microbial agent may be formulated in any suitable manner into other components of the dressing <NUM>.

Referring to <FIG>, the fluid management assembly <NUM> may be configured to offload or move fluid extracted from the tissue site <NUM> away from an articulation area <NUM> at the tissue site <NUM>, shown in <FIG>. The articulation area <NUM> at the tissue site <NUM> is a moveable joint <NUM>, such as, for example, a knee or elbow. Further, the articulation area <NUM> may include a treatment surface <NUM> upon which the dressing <NUM> and the fluid management assembly <NUM> may be positioned as shown in <FIG>, for example. The configurations of the fluid management assembly <NUM> and the dressing <NUM> described herein may improve articulation, movement, and range of motion at the articulation area <NUM> by, for example, reducing an amount of fluid stored at the articulation area <NUM> and/or reducing buckling or interference between portions of the dressing <NUM>.

As shown in <FIG>, the fluid management assembly <NUM> may be a fluid management assembly 144a, 144b, 144c, 144d, 144e, 144f, <NUM>, <NUM>, 144i, 144j, <NUM>, <NUM>, <NUM>, 144n, 144o, 144p, 144q, 144r, <NUM>, 144t, 144u, 144v, or 144w. Among the various embodiments of the fluid management assembly 144a-144w set forth above, like reference numerals refer to like features in the figures, and thus, like features shown and described in connection with one embodiment are applicable to other embodiments unless explicitly stated otherwise.

Continuing with <FIG>, the fluid management assembly <NUM> may include a first end <NUM> and a second end <NUM> positioned opposite from the first end <NUM>. Further, the fluid management assembly <NUM> may include a first side <NUM> and a second side <NUM> positioned opposite from the first side <NUM>. Further, the fluid management assembly <NUM> may include a first axis <NUM> and a second axis <NUM> that is perpendicular or normal to the first axis <NUM>.

The fluid management assembly <NUM> includes an articulation zone <NUM>, which is also referred to as a first zone <NUM>. The first axis <NUM> and the second axis <NUM> may each extend along the articulation zone <NUM> or the first zone <NUM> and intersect at the articulation zone <NUM> or the first zone <NUM>. Further, the fluid management assembly <NUM> includes a fluid dispersion zone <NUM>, which may also be referred to as a second zone <NUM>. The fluid dispersion zone <NUM> or the second zone <NUM> may be positioned outbound and coplanar to the articulation zone <NUM> or the first zone <NUM>. In some embodiments, the fluid management assembly <NUM> may have a substantially symmetrical shape across at least one of the first axis <NUM> and the second axis <NUM>. Further, in some embodiments, the articulation zone <NUM> or the first zone <NUM> may be in fluid communication with the fluid dispersion zone <NUM> or the second zone <NUM> from the first end <NUM> of the fluid management assembly <NUM> to the opposing second end <NUM> of the fluid management assembly <NUM>.

The articulation zone <NUM> or the first zone <NUM> are configured to be positioned at the articulation area <NUM> at the tissue site <NUM>, shown in <FIG>. <FIG> depicts an illustrative example embodiment of the fluid management assembly 144a positioned at the articulation area <NUM> of <FIG>. <FIG> depicts another illustrative example embodiment of the fluid management assembly 144q positioned at the articulation area <NUM> of <FIG>. The fluid dispersion zone <NUM> or the second zone <NUM> is configured to offload or move fluid away from the articulation zone <NUM> or the first zone <NUM>. Further the fluid dispersion zone <NUM> or the second zone <NUM> may be configured to offload or move fluid away from the articulation area <NUM> at the tissue site <NUM>.

The articulation zone <NUM> or the first zone <NUM> is configured to cover at least a portion of the articulation area <NUM> at the tissue site <NUM>, and the fluid dispersion zone <NUM> or the second zone <NUM> may be configured to be positioned outbound, displaced, or away from the articulation area <NUM>. Further, in some embodiments, the fluid dispersion zone <NUM> or the second zone <NUM> may be configured to be positioned farther away from the articulation area <NUM> at the tissue site <NUM> than the articulation zone <NUM> or the first zone <NUM>. Further, in some embodiments, the articulation zone <NUM> and the fluid dispersion zone <NUM> are coplanar and configured to be positioned substantially parallel to the treatment surface <NUM> at the tissue site <NUM>. Further, the first zone <NUM> and the second zone <NUM> are coplanar and configured to be positioned substantially parallel to the treatment surface <NUM> at the tissue site <NUM>. In some embodiments, the fluid dispersion zone <NUM> or the second zone <NUM> may be configured to absorb more fluid than the articulation zone <NUM> or the first zone 266The first zone <NUM> includes a first absorbent capacity that is less than a second absorbent capacity of the second zone <NUM>.

Referring to <FIG>, <FIG>, <FIG>, and <FIG>, in some embodiments, the fluid dispersion zone <NUM> or the second zone <NUM> may include a plurality of fluid dispersion zones <NUM> or a plurality of second zones <NUM>. In some embodiments, at least one of the fluid dispersion zones <NUM> or the second zones <NUM> may be positioned at each of the opposing first end <NUM> and the second end <NUM> of the fluid management assembly <NUM>. In some embodiments, the articulation zone <NUM> or the first zone <NUM> may be positioned between the fluid dispersion zones <NUM> or the second zones <NUM>.

Referring to <FIG>, in some embodiments, an articulation manifold <NUM> including cross-cuts or flexibility notches <NUM> may be positioned at the articulation zone <NUM> or the first zone <NUM> and between the fluid dispersion zones <NUM> or the second zones <NUM>. The articulation manifold <NUM> may be formed of or comprise similar materials as described herein for the interface manifold <NUM>, which may be hydrophobic.

In some embodiments, the articulation zone <NUM> or the first zone <NUM> may include less of the absorbent material <NUM> than the fluid dispersion zone <NUM> or the second zone <NUM>. For example, the absorbent material <NUM> of the fluid management assembly <NUM> may include a tapered or narrowed dimension at or proximate to the articulation zone <NUM> or the first zone <NUM> as shown illustratively at least in <FIG>, <FIG>, <FIG>, and <FIG>. Further, in some embodiments, the articulation zone <NUM> or the first zone <NUM> may be free of the absorbent material <NUM>. For example, in some embodiments, the articulation zone <NUM> or the first zone <NUM> may include an opening <NUM> disposed through the fluid management assembly <NUM> as shown illustratively at least in <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>.

Referring to <FIG>, in some embodiments, the articulation zone <NUM> or the first zone <NUM> may be positioned at the first end <NUM> of the fluid management assembly <NUM>, and the fluid dispersion zone <NUM> or the second zone <NUM> may be positioned at the opposing second end <NUM> of the fluid management assembly <NUM>.

Referring to <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, in some embodiments, the articulation zone <NUM> or the first zone <NUM> may include at least one relief area <NUM> positioned on the opposing first side <NUM> and the second side <NUM> of the fluid management assembly <NUM> at the articulation zone <NUM> or the first zone <NUM>. The first side <NUM> and the second side <NUM> may form the outer edges or outer boundary of the fluid management assembly <NUM>. The at least one relief area <NUM> may form or be a gap, a slot, a taper, or cut at the first and the second side <NUM>, <NUM> or the outer edges or outer boundary of the fluid management assembly <NUM> that may provide space for other portions of the fluid management assembly <NUM> or the dressing <NUM> to bend into or occupy as the dressing <NUM> articulates at the articulation area <NUM>. Such a configuration may reduce buckling or interference between portions of the dressing <NUM> that may provide improved articulation, movement, and range of motion at the articulation area <NUM> and the tissue site <NUM>.

In some embodiments, the at least one relief area <NUM> may be a plurality of relief areas <NUM>, and the articulation zone <NUM> or the first zone <NUM> may include a plurality of fluid pockets <NUM>. In some embodiments, the plurality of relief areas <NUM> may be separated from each other by the fluid pockets <NUM>. Further, in some embodiments, the plurality of fluid pockets <NUM> and the plurality of relief areas <NUM> may alternate along the opposing first side <NUM> and the second side <NUM> of the fluid management assembly <NUM> at or proximate to the articulation zone <NUM> or the first zone <NUM>. The fluid pockets <NUM> may form or be fluid storage areas positioned proximate to one or more of the relief areas <NUM>. The fluid pockets <NUM> may move and occupy or close a gap or space created by one or more of the relief areas <NUM> as the fluid management assembly <NUM> and the dressing <NUM> articulates at the tissue site <NUM> as shown in <FIG>, for example.

Referring to <FIG>, <FIG>, and <FIG>, the conduit interface <NUM> may be positioned proximate to the sealing member <NUM> and in fluid communication with the dressing <NUM> through the sealing member aperture <NUM> in the sealing member <NUM> to provide reduced pressure from the reduced-pressure source <NUM> to the dressing <NUM>. Specifically, the conduit interface <NUM> may be positioned in fluid communication with the enclosure <NUM> of the dressing <NUM>. The conduit interface <NUM> may also be positioned in fluid communication with the optional interface manifold <NUM>. As shown, an optional liquid trap <NUM> may be positioned in fluid communication between the dressing <NUM> and the reduced-pressure source <NUM>. The liquid trap <NUM> may be any suitable containment device having a sealed internal volume capable of retaining liquid, such as condensate or other liquids, as described below.

The conduit interface <NUM> may comprise a medical-grade, soft polymer or other pliable material. As non-limiting examples, the conduit interface <NUM> may be formed from polyurethane, polyethylene, polyvinyl chloride (PVC), fluorosilicone, or ethylenepropylene, etc. In some illustrative, non-limiting embodiments, conduit interface <NUM> may be molded from DEHP-free PVC. The conduit interface <NUM> may be formed in any suitable manner such as by molding, casting, machining, or extruding. Further, the conduit interface <NUM> may be formed as an integral unit or as individual components and may be coupled to the dressing <NUM> by, for example, adhesive or welding.

In some embodiments, the conduit interface <NUM> may be formed of an absorbent material having absorbent and evaporative properties. The absorbent material may be vapor permeable and liquid impermeable, thereby being configured to permit vapor to be absorbed into and evaporated from the material through permeation while inhibiting permeation of liquids. The absorbent material may be, for example, a hydrophilic polymer such as a hydrophilic polyurethane. Although the term hydrophilic polymer may be used in the illustrative embodiments that follow, any absorbent material having the properties described herein may be suitable for use in the system <NUM>. Further, the absorbent material or hydrophilic polymer may be suitable for use in various components of the system <NUM> as described herein.

The use of such a hydrophilic polymer for the conduit interface <NUM> may permit liquids in the conduit interface <NUM> to evaporate, or otherwise dissipate, during operation. For example, the hydrophilic polymer may allow the liquid to permeate or pass through the conduit interface <NUM> as vapor, in a gaseous phase, and evaporate into the atmosphere external to the conduit interface <NUM>. Such liquids may be, for example, condensate or other liquids. Condensate may form, for example, as a result of a decrease in temperature within the conduit interface <NUM>, or other components of the system <NUM>, relative to the temperature at the tissue site <NUM>. Removal or dissipation of liquids from the conduit interface <NUM> may increase visual appeal and prevent odor. Further, such removal of liquids may also increase efficiency and reliability by reducing blockages and other interference with the components of the system <NUM>.

Similar to the conduit interface <NUM>, the liquid trap <NUM>, and other components of the system <NUM> described herein, may also be formed of an absorbent material or a hydrophilic polymer. The absorptive and evaporative properties of the hydrophilic polymer may also facilitate removal and dissipation of liquids residing in the liquid trap <NUM>, and other components of the system <NUM>, by evaporation. Such evaporation may leave behind a substantially solid or gel-like waste. The substantially solid or gel-like waste may be cheaper to dispose than liquids, providing a cost savings for operation of the system <NUM>. The hydrophilic polymer may be used for other components in the system <NUM> where the management of liquids is beneficial.

In some embodiments, the absorbent material or hydrophilic polymer may have an absorbent capacity in a saturated state that is substantially equivalent to the mass of the hydrophilic polymer in an unsaturated state. The hydrophilic polymer may be fully saturated with vapor in the saturated state and substantially free of vapor in the unsaturated state. In both the saturated state and the unsaturated state, the hydrophilic polymer may retain substantially the same physical, mechanical, and structural properties. For example, the hydrophilic polymer may have a hardness in the unsaturated state that is substantially the same as a hardness of the hydrophilic polymer in the saturated state. The hydrophilic polymer and the components of the system <NUM> incorporating the hydrophilic polymer may also have a size that is substantially the same in both the unsaturated state and the saturated state. Further, the hydrophilic polymer may remain dry, cool to the touch, and pneumatically sealed in the saturated state and the unsaturated state. The hydrophilic polymer may also remain substantially the same color in the saturated state and the unsaturated state. In this manner, this hydrophilic polymer may retain sufficient strength and other physical properties to remain suitable for use in the system <NUM>. An example of such a hydrophilic polymer is offered under the trade name Techophilic HP-93A-<NUM>, available from The Lubrizol Corporation of Wickliffe, Ohio, United States. Techophilic HP-93A-<NUM> is an absorbent hydrophilic thermoplastic polyurethane capable of absorbing <NUM>% of the unsaturated mass of the polyurethane in water and having a durometer or Shore Hardness of about <NUM> Shore A.

The conduit interface <NUM> may carry an odor filter <NUM> adapted to substantially preclude the passage of odors from the tissue site <NUM> out of the sealed space <NUM>. Further, the conduit interface <NUM> may carry an optional primary hydrophobic filter <NUM> adapted to substantially preclude the passage of liquids out of the sealed space <NUM>. The odor filter <NUM> and the primary hydrophobic filter <NUM> may be disposed in the conduit interface <NUM> or other suitable location such that fluid communication between the reduced-pressure source <NUM>, or optional therapy unit <NUM>, and the dressing <NUM> is provided through the odor filter <NUM> and the primary hydrophobic filter <NUM>. In some embodiments, the odor filter <NUM> and the primary hydrophobic filter <NUM> may be secured within the conduit interface <NUM> in any suitable manner, such as by adhesive or welding. In other embodiments, the odor filter <NUM> and the primary hydrophobic filter <NUM> may be positioned in any exit location in the dressing <NUM> that is in fluid communication with the atmosphere, the reduced-pressure source <NUM>, or the optional therapy unit <NUM>. The odor filter <NUM> may also be positioned in any suitable location in the system <NUM> that is in fluid communication with the tissue site <NUM>.

The odor filter <NUM> may be comprised of a carbon material in the form of a layer or particulate. For example, the odor filter <NUM> may comprise a woven carbon cloth filter such as those manufactured by Chemviron Carbon, Ltd. of Lancashire, United Kingdom. The primary hydrophobic filter <NUM> may be comprised of a material that is liquid impermeable and vapor permeable. For example, the primary hydrophobic filter <NUM> may comprise a material manufactured under the designation MMT-<NUM> by W. Gore & Associates, Inc. of Newark, Delaware, United States, or similar materials. The primary hydrophobic filter <NUM> may be provided in the form of a membrane or layer.

Continuing with <FIG>, <FIG>, and <FIG>, the reduced-pressure source <NUM> provides reduced pressure to the dressing <NUM> and the sealed space <NUM>. The reduced-pressure source <NUM> may be any suitable device for providing reduced pressure, such as, for example, a vacuum pump, wall suction, hand pump, manual pump, electronic pump, micro-pump, piezoelectric pump, diaphragm pump, or other source. As shown in <FIG>, the reduced-pressure source <NUM> may be a component of the therapy unit <NUM>. The therapy unit <NUM> may include control circuitry and sensors, such as a pressure sensor, that may be configured to monitor reduced pressure at the tissue site <NUM>. The therapy unit <NUM> may also be configured to control the amount of reduced pressure from the reduced-pressure source <NUM> being applied to the tissue site <NUM> according to a user input and a reduced-pressure feedback signal received from the tissue site <NUM>.

As used herein, "reduced pressure" generally refers to a pressure less than the ambient pressure at a tissue site being subjected to treatment. Typically, this reduced pressure will be less than the atmospheric pressure. The reduced pressure may also be less than a hydrostatic pressure at a tissue site. Unless otherwise indicated, values of pressure stated herein are gauge pressures. While the amount and nature of reduced pressure applied to a tissue site will typically vary according to the application, the reduced pressure will typically be between -<NUM> Hg and -<NUM> Hg, and more typically in a therapeutic range between -<NUM> Hg and -<NUM> Hg.

The reduced pressure delivered may be constant or varied (patterned or random), and may be delivered continuously or intermittently. Although the terms "vacuum" and "negative pressure" may be used to describe the pressure applied to the tissue site, the actual pressure applied to the tissue site may be more than the pressure normally associated with a complete vacuum. Consistent with the use herein, an increase in reduced pressure or vacuum pressure typically refers to a relative reduction in absolute pressure. An increase in reduced pressure corresponds to a reduction in pressure (more negative relative to ambient pressure) and a decrease in reduced pressure corresponds to an increase in pressure (less negative relative to ambient pressure).

As shown in <FIG>, a conduit <NUM> having an internal lumen <NUM> may be coupled in fluid communication between the reduced-pressure source <NUM> and the dressing <NUM>. The internal lumen <NUM> may have an internal diameter between about <NUM> millimeters to about <NUM> millimeters. More specifically, the internal diameter of the internal lumen <NUM> may be about <NUM> millimeter to about <NUM> millimeters. The conduit interface <NUM> may be coupled in fluid communication with the dressing <NUM> and adapted to connect between the conduit <NUM> and the dressing <NUM> for providing fluid communication with the reduced-pressure source <NUM>. The conduit interface <NUM> may be fluidly coupled to the conduit <NUM> in any suitable manner, such as, for example, by an adhesive, solvent or non-solvent bonding, welding, or interference fit. The sealing member aperture <NUM> in the sealing member <NUM> may provide fluid communication between the dressing <NUM> and the conduit interface <NUM>. Specifically, the conduit interface <NUM> may be in fluid communication with the enclosure <NUM> or the sealed space <NUM> through the sealing member aperture <NUM> in the sealing member <NUM>. In some embodiments, the conduit <NUM> may be inserted into the dressing <NUM> through the sealing member aperture <NUM> in the sealing member <NUM> to provide fluid communication with the reduced-pressure source <NUM> without use of the conduit interface <NUM>. The reduced-pressure source <NUM> may also be directly coupled in fluid communication with the dressing <NUM> or the sealing member <NUM> without use of the conduit <NUM>. The conduit <NUM> may be, for example, a flexible polymer tube. A distal end of the conduit <NUM> may include a coupling <NUM> for attachment to the reduced-pressure source <NUM>. Accordingly, the reduced-pressure source <NUM> may be configured to be coupled in fluid communication with the enclosure <NUM> of the dressing <NUM> through the sealing member aperture <NUM> in a variety of ways.

The conduit <NUM> may have an optional secondary hydrophobic filter <NUM> disposed in the internal lumen <NUM> such that fluid communication between the reduced-pressure source <NUM> and the dressing <NUM> is provided through the secondary hydrophobic filter <NUM>. The secondary hydrophobic filter <NUM> may be, for example, a porous, sintered polymer cylinder sized to fit the dimensions of the internal lumen <NUM> to substantially preclude liquid from bypassing the cylinder. The secondary hydrophobic filter <NUM> may also be treated with an absorbent material adapted to swell when brought into contact with liquid to block the flow of the liquid. The secondary hydrophobic filter <NUM> may be positioned at any location within the internal lumen <NUM>. However, positioning the secondary hydrophobic filter <NUM> within the internal lumen <NUM> closer toward the reduced-pressure source <NUM>, rather than the dressing <NUM>, may allow a user to detect the presence of liquid in the internal lumen <NUM>.

In some embodiments, the conduit <NUM> and the coupling <NUM> may be formed of an absorbent material or a hydrophilic polymer as described above for the conduit interface <NUM>. In this manner, the conduit <NUM> and the coupling <NUM> may permit liquids in the conduit <NUM> and the coupling <NUM> to evaporate, or otherwise dissipate, as described above for the conduit interface <NUM>. The conduit <NUM> and the coupling <NUM> may be, for example, molded from the hydrophilic polymer separately, as individual components, or together as an integral component. Further, a wall of the conduit <NUM> defining the internal lumen <NUM> may be extruded from the hydrophilic polymer. The conduit <NUM> may be less than about <NUM> meter in length, but may have any length to suit a particular application. More specifically, a length of about <NUM> foot or <NUM> millimeters may provide enough absorbent and evaporative surface area to suit many applications, and may provide a cost savings compared to longer lengths. If an application requires additional length for the conduit <NUM>, the absorbent hydrophilic polymer may be coupled in fluid communication with a length of conduit formed of a non-absorbent hydrophobic polymer to provide additional cost savings.

In operation of the system <NUM> according to some illustrative embodiments, the optional interface manifold <NUM> may be disposed against or proximate to the tissue site <NUM>. The dressing <NUM> may then be applied over the interface manifold <NUM> and the tissue site <NUM> to form the sealed space <NUM>. Specifically, the base layer <NUM> may be applied covering the interface manifold <NUM> and the tissue surrounding the tissue site <NUM>. In embodiments that omit the interface manifold <NUM>, the dressing <NUM> may be applied over, in contact with, or covering the tissue site <NUM> and tissue around the tissue site <NUM>.

The materials described above for the base layer <NUM> have a tackiness that may hold the dressing <NUM> initially in position. The tackiness may be such that if an adjustment is desired, the dressing <NUM> may be removed and reapplied. Once the dressing <NUM> is in the desired position, a force may be applied, such as by hand pressing, on a side of the sealing member <NUM> opposite the tissue site <NUM>. The force applied to the sealing member <NUM> may cause at least some portion of the adhesive <NUM> to penetrate or extend through the plurality of apertures <NUM> and into contact with tissue surrounding the tissue site <NUM>, such as the epidermis <NUM>, to releaseably adhere the dressing <NUM> about the tissue site <NUM>. In this manner, the configuration of the dressing <NUM> described above may provide an effective and reliable seal against challenging anatomical surfaces, such as an elbow or heal, at and around the tissue site <NUM>. Further, the dressing <NUM> permits re-application or re-positioning to, for example, correct air leaks caused by creases and other discontinuities in the dressing <NUM> and the tissue site <NUM>. The ability to rectify leaks may increase the reliability of the therapy and reduce power consumption.

As the dressing <NUM> comes into contact with fluid from the tissue site <NUM>, the fluid moves through the apertures <NUM> toward the fluid management assembly <NUM>. The fluid management assembly <NUM> wicks or otherwise moves the fluid through the interface manifold <NUM> and away from the tissue site <NUM>. As described above, the interface manifold <NUM> may be adapted to communicate fluid from the tissue site <NUM> rather than store the fluid. Thus, the fluid management assembly <NUM> may be more absorbent than the interface manifold <NUM>. The fluid management assembly <NUM> being more absorbent than the interface manifold <NUM> provides an absorbent gradient through the dressing <NUM> that attracts fluid from the tissue site <NUM> or the interface manifold <NUM> to the fluid management assembly <NUM>. Thus, in some embodiments, the fluid management assembly <NUM> may be adapted to wick, pull, draw, or otherwise attract fluid from the tissue site <NUM> through the interface manifold <NUM>. In the fluid management assembly <NUM>, the fluid initially comes into contact with the first wicking layer <NUM>. The first wicking layer <NUM> may distribute the fluid laterally along the surface of the first wicking layer <NUM> as described above for absorption and storage within the absorbent layer <NUM>. Similarly, fluid coming into contact with the second wicking layer <NUM> may be distributed laterally along the surface of the second wicking layer <NUM> for absorption within the absorbent layer <NUM>.

Referring to <FIG>, in other embodiments, the conduit <NUM> may be a multi-lumen conduit <NUM>. For example, <FIG> depicts an illustrative embodiment of a multi-lumen conduit 302a. The multi-lumen conduit 302a may have an external surface <NUM>, a primary lumen <NUM>, a wall <NUM>, and at least one secondary lumen <NUM>. The wall <NUM> may carry the primary lumen <NUM> and the at least one secondary lumen <NUM>. The primary lumen <NUM> may be substantially isolated from fluid communication with the at least one secondary lumen <NUM> along the length of the multi-lumen conduit 302a. Although shown in <FIG> as having a substantially circular cross-section, the external surface <NUM> of the multi-lumen conduit 302a may have any shape to suit a particular application. The wall <NUM> of the multi-lumen conduit 302a may have a thickness between the primary lumen <NUM> and the external surface <NUM>. As depicted in <FIG>, the at least one secondary lumen <NUM> may be four secondary lumens <NUM> carried by the wall <NUM> substantially parallel to the primary lumen <NUM> and about a perimeter of the primary lumen <NUM>. The secondary lumens <NUM> may be separate from one another and substantially isolated from fluid communication with one another along the length of the multi-lumen conduit 302a. Further, the secondary lumens <NUM> may be separate from the primary lumen <NUM> and substantially isolated from fluid communication with the primary lumen <NUM>. The secondary lumens <NUM> may also be positioned concentric relative to the primary lumen <NUM> and substantially equidistant about the perimeter of the primary lumen <NUM>. Although <FIG> depicts four secondary lumens <NUM>, any number of secondary lumens <NUM> may be provided and positioned in any suitable manner for a particular application.

Similar to the internal lumen <NUM> of the conduit <NUM>, the primary lumen <NUM> may be coupled in fluid communication between the reduced-pressure source <NUM> and the dressing <NUM> as described above. In some embodiments, the primary lumen <NUM> may be coupled in fluid communication between the conduit interface <NUM> and the reduced-pressure source <NUM>. Further, analogous to the internal lumen <NUM>, reduced pressure may be provided through the primary lumen <NUM> from the reduced-pressure source <NUM> to the dressing <NUM>. In some embodiments, the primary lumen <NUM> may be configured to extract fluid such as exudate from the tissue site <NUM>. The secondary lumens <NUM> may be coupled in fluid communication between the therapy unit <NUM> and the dressing <NUM>. In some embodiments, the at least one secondary lumen <NUM> may be coupled in fluid communication between the conduit interface <NUM> and the therapy unit <NUM>. Further, the secondary lumens <NUM> may be in fluid communication with the primary lumen <NUM> at the dressing <NUM> and configured to provide a reduced-pressure feedback signal from the dressing <NUM> to the therapy unit <NUM>. For example, the secondary lumens <NUM> may be in fluid communication with the primary lumen <NUM> at the conduit interface <NUM> or other component of the dressing <NUM>.

The multi-lumen conduit 302a may be comprised of an absorbent material or hydrophilic polymer, such as, for example, the absorbent material or the hydrophilic polymer described above in connection with the conduit interface <NUM>, the conduit <NUM>, and the coupling <NUM>. The absorbent material or the hydrophilic polymer may be vapor permeable and liquid impermeable. In some embodiments, at least a portion of the wall <NUM> and the external surface <NUM> of the multi-lumen conduit 302a may be comprised of the absorbent material or the hydrophilic polymer. In this manner, the multi-lumen conduit 302a may permit liquids, such as condensate, in the multi-lumen conduit 302a to evaporate, or otherwise dissipate, as described above. For example, the absorbent material or the hydrophilic polymer may allow the liquid to pass through the multi-lumen conduit 302a as vapor, in a gaseous phase, and evaporate into the atmosphere external to the multi-lumen conduit 302a. Liquids such as exudate from the tissue site <NUM> may also be evaporated or dissipated through the multi-lumen conduit 302a in the same manner. This feature may be advantageous when the optional therapy unit <NUM> is used for monitoring and controlling reduced pressure at the tissue site <NUM>. For example, liquid present in the secondary lumens <NUM> may interfere with a reduced-pressure feedback signal being transmitted to the therapy unit <NUM> through the secondary lumens <NUM>. The use of the hydrophilic polymer for the multi-lumen conduit 302a may permit removal of such liquid for enhancing the visual appeal, reliability, and efficiency of the system <NUM>. After evaporation of liquid in the multi-lumen conduit 302a, other blockages from, for example, desiccated exudate, solids, or gel-like substances that were carried by the evaporated liquid may be visible for further remediation. Further, the use of the hydrophilic polymer as described herein may reduce the occurrence of skin damage caused by moisture buildup between components of the system <NUM>, such as the multi-lumen conduit 302a, and the skin of a patient.

Referring to <FIG>, depicted is an illustrative embodiment of a multi-lumen conduit 302e having an oblong cross section. Similar to the multi-lumen conduit 302a, the multi-lumen conduit 302e may have the external surface <NUM>, the primary lumen <NUM>, the wall <NUM>, and the at least one secondary lumen <NUM>. However, <FIG> depicts the at least one secondary lumen <NUM> of the multi-lumen conduit 302e as a single secondary lumen <NUM> that may be carried by the wall <NUM> beside the primary lumen <NUM>. Such a configuration may provide a substantially flat, low profile shape that may enhance user comfort and may increase the flexibility of the multi-lumen conduit 302e. For example, in this configuration, the multi-lumen conduit 302e may be routed through tight spaces with reduced risk of kinking or blockages of fluid communication. Although not depicted, additional lumens may be added in this substantially flat configuration, laterally disposed from the primary lumen <NUM> and the secondary lumen <NUM>, as necessary to suit a particular application. The above features described in connection with the multi-lumen conduits 302a and 302e may be used in combination with one another to suit a particular application.

Claim 1:
A system (<NUM>) for treating a tissue site (<NUM>) having an articulation area (<NUM>),
wherein the articulation area (<NUM>) is a moveable joint (<NUM>), the system (<NUM>) comprising:
a dressing (<NUM>), comprising:
a base layer (<NUM>) including a periphery (<NUM>) surrounding a central portion (<NUM>),
a sealing member (<NUM>) including a periphery (<NUM>) and a central portion (<NUM>), the periphery (<NUM>) of the sealing member positioned proximate to the periphery (<NUM>) of the base layer (<NUM>), wherein the central portion (<NUM>) of the sealing member (<NUM>) and the central portion (<NUM>) of the base layer (<NUM>) define an enclosure (<NUM>), and
a fluid management assembly (<NUM>) disposed in the enclosure (<NUM>) and including a first zone (<NUM>) and a second zone (<NUM>), wherein the first zone (<NUM>) is a movable joint for positioning at the articulation area (<NUM>) of the tissue site, wherein the first zone (<NUM>) is coplanar to the second zone (<NUM>) and is for positioning substantially parallel to a treatment surface at the tissue site, the first zone (<NUM>) includes a first absorbent capacity that is less than a second absorbent capacity of the second zone (<NUM>), and wherein the second zone (<NUM>) is configured to offload fluid away from the first zone (<NUM>) by having a greater absorbent capacity than the first zone; and
a reduced-pressure source (<NUM>) coupled in fluid communication with the enclosure (<NUM>).