WO2020092598A1

WO2020092598A1 - Ease of use dressing with integrated pouch and release liner

Info

Publication number: WO2020092598A1
Application number: PCT/US2019/058902
Authority: WO
Inventors: Christopher Brian Locke; Timothy Mark Robinson
Original assignee: Kci Licensing, Inc.
Priority date: 2018-10-30
Filing date: 2019-10-30
Publication date: 2020-05-07

Abstract

Dressings and dressing kits with integrated packaging are disclosed, which may include a dressing comprising a contact layer having a tacky surface and a package having a first package layer and a second package layer. The first package layer may be positioned against the tacky surface of the contact layer, and the second package layer may be positioned adjacent a surface of the contact layer opposite the tacky surface. The first package layer and the second package layer may be joined around a perimeter of the contact layer to provide a sealed, sterile compartment around the contact layer. In some embodiments the dressing may include additional film and/or other manifold layers.

Description

EASE OF USE DRESSING WITH INTEGRATED POUCH AND RELEASE LINER

RELATED APPLICATIONS

[0001] The present application claims priority to U.S. Provisional Patent Application No. 62/752,458, entitled“Ease of Use Dressing with Integrated Pouch and Release Liner,” filed October 30, 2018, which is incorporated herein by reference for all purposes.

TECHNICAL FIELD

[0002] The invention set forth in the appended claims relates generally to tissue treatment systems and more particularly, but without limitation, to dressings and associated packaging materials for dressings for tissue treatment as well as methods of using the dressings and accompanying packaging materials.

BACKGROUND

[0003] Dressings and associated materials for applying to a tissue site, such as a wound, are typically stored in sterile packaging materials prior to use. For example, sterile wound dressings can be sealed within sterile pouches during manufacturing to protect the dressings from contamination prior to application to the tissue site. During application of the dressing, the dressing can be removed from the packaging, which may involve peeling the packaging layers apart from each other as well as from the enclosed dressing. The dressings or dressing materials enclosed within the sterile packaging may include multiple dressing layers, which may include one or more protective layers, such as a release liner, that is necessary to remove or peel away from the dressing prior to application to the tissue site. Improvements to the designs of the packaging as well as protective layers used in storing tissue dressing materials may offer significant benefits to healthcare providers and patients. BRIEF SUMMARY

[0004] New and useful systems, apparatuses, and methods related to treating tissue 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.

[0005] For example, in some embodiments, a kit for treating a tissue site may comprise a dressing comprising a contact layer having a tacky surface, a release layer, and a package layer. The release layer may be positioned against the tacky surface of the contact layer, and the package layer may be positioned adjacent a surface of the contact layer opposite the tacky surface. The release layer and the package layer may be joined around a perimeter of the contact layer to provide a sterile compartment around the contact layer. In some embodiments, the contact layer may comprise a hydrophobic gel, which may further comprise a plurality of apertures. In some embodiments, the release layer may comprise an outer film layer comprising a transparent material and an inner layer comprising a material adapted to assist with heat sealing a perimeter edge of the release layer to a perimeter edge of the package layer.

[0006] In some additional embodiments, a dressing kit may comprise a dressing and an envelope. The dressing may comprise a first surface and a second surface, wherein the first surface is tacky. The envelope may comprise a first envelope layer and a second envelope layer. The first envelope layer may be coupled to the first surface of the dressing and may be adapted to protect the first surface. The second envelope layer may be positioned adjacent the second surface of the dressing. The first envelope layer and the second envelope layer may be joined around a perimeter of the dressing to provide a sealed, sterile compartment around the dressing.

[0007] In further embodiments, a dressing kit may comprise a dressing and a pouch. The dressing may include a first layer comprising a hydrophobic gel, a second layer comprising a polymer film, and a third layer coupled to the second layer opposite the first layer, wherein the third layer comprises a polymer drape having an adhesive disposed on a first side. The pouch may include a release layer and a package layer. The release layer may be coupled to the first layer of the dressing opposite the second layer of the dressing, wherein the release layer is adapted to be peeled away from the first layer. The package layer may be positioned adjacent the third layer of the dressing. A perimeter edge of the release layer and a perimeter edge of the package layer may be joined so that the pouch forms a sealed compartment around the dressing.

[0008] A method of manufacturing a packaged dressing is also described herein, wherein some example embodiments may include assembling a plurality of dressing layers in a stack to form a dressing, positioning the dressing on an internal surface of a first package layer, positioning a second package layer over the dressing layers, and welding a perimeter of the first package layer to a perimeter of the second package layer to form a sealed pouch around the dressing. The plurality of dressing layers may include a first layer comprising a tacky outer surface and a second layer comprising a polymer drape. Positioning the dressing on an internal surface of the first package layer may include placing the tacky outer surface of the first layer in contact with a central portion of the first package layer. Positioning the second package layer over the dressing layers may include positioning the second package layer on an outer surface of the second layer of the dressing layers.

[0009] 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

[0010] Figure 1 is a schematic diagram of an example embodiment of a dressing kit in accordance with this specification;

[0011] Figure 2 is an assembly view of an example of a dressing kit incorporating an example embodiment of a dressing, illustrating additional details that may be associated with some example embodiments of the dressing kit of Figure 1;

[0012] Figure 3 is an assembly view of another example of a dressing kit incorporating an example embodiment of a tissue interface, illustrating additional details that may be associated with some example embodiments of the dressing kit of Figure 1;

[0013] Figure 4 is an assembly view of another example of a dressing kit incorporating another embodiment of a dressing, illustrating additional details that may be associated with some example embodiments of the dressing kit of Figure 1;

[0014] Figure 5 is a schematic view of the example dressing kit of Figure 4, illustrating some additional details that may be associated with some example embodiments;

[0015] Figures 6A-6D are schematic diagrams showing additional details that may be associated with the use of a dressing kit incorporating an example embodiment of a tissue interface, according to some illustrative embodiments; and

[0016] Figure 7 is a functional block diagram of an example embodiment of a therapy system that can provide negative-pressure treatment in accordance with this specification.

DESCRIPTION OF EXAMPLE EMBODIMENTS

[0017] The following description of example embodiments provides information that enables a person skilled in the art to make and use the subject matter set forth in the appended claims, but it may omit certain details already well-known in the art. The following detailed description is, therefore, to be taken as illustrative and not limiting.

[0018] 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.

[0019] Figure 1 is a schematic view of an example of a dressing kit 100, which may include a pouch 105 and a dressing 110 contained within the pouch 105. The pouch 105 may be in the form of a package or envelope that may provide a sealed, protective enclosure around the dressing 110 in order to preserve the sterility of the dressing 110 prior to application to a tissue site.

[0020] The term“tissue site” in this context broadly refers to a wound, defect, or other treatment target located on or within tissue, including, but not limited to, bone tissue, adipose tissue, muscle tissue, neural tissue, dermal tissue, vascular tissue, connective tissue, cartilage, tendons, or ligaments. A wound may include chronic, acute, traumatic, subacute, and dehisced wounds, partial-thickness bums, ulcers (such as diabetic, pressure, or venous insufficiency ulcers), flaps, and grafts, for example. The term“tissue site” may also refer to areas of any tissue that are not necessarily wounded or defective, but are instead areas in which it may be desirable to add or promote the growth of additional tissue.

[0021] In some embodiments, the pouch 105 may include a release layer 120 and a package layer 130, wherein the dressing 110 may be positioned between the release layer 120 and the package layer 130. The release layer 120 and the package layer 130 may be sealed together around the perimeter of the dressing 110 in order to enclose the dressing 110. In some embodiments, the pouch 105 may be formed by at least a portion of the release layer 120 being sealed, such as by heat sealing, to at least a portion of the package layer 130. As illustrated in the example of Figure 1, in some embodiments, the pouch 105 may provide a fluidly-sealed compartment for containing the dressing 110 in a sterile environment prior to use by a perimeter of the release layer 120 being heat-sealed to a perimeter of the package layer 130.

[0022] Figure 2 is an assembly view of an example of a dressing kit 100 including an example embodiment of the dressing 110 of Figure 1 positioned between the release layer 120 and the package layer 130 of the pouch 105 of Figure 1, illustrating additional details that may be associated with some embodiments. As illustrated in Figure 2, some embodiments of the dressing 110 may include a tissue interface 210 and a cover 215.

[0023] The tissue interface 210 can be generally adapted to partially or fully contact a tissue site. The tissue interface 210 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 210 may be adapted to the contours of deep and irregular shaped tissue sites.

[0024] In some embodiments, the tissue interface 210 may comprise or consist essentially of a manifold. In some illustrative embodiments, a manifold may comprise a plurality of pathways, which can be interconnected to improve distribution or collection of fluids. A manifold in this context may comprise or consist essentially of a means for collecting or distributing fluid across the tissue interface 210, which may occur under pressure. For example, a manifold may be adapted to receive negative pressure from a source and distribute negative pressure through multiple apertures across the tissue interface 210, which may have the effect of collecting fluid from across a tissue site and drawing the fluid toward the source. In some embodiments, the fluid path may be reversed or a secondary fluid path may be provided to facilitate delivering fluid across a tissue site. In some embodiments, the tissue interface 210 may include or be constructed from bioresorbable materials, such as a polymeric blend of polylactic acid (PLA) and polyglycolic acid (PGA). The tissue interface 210 may further serve as a scaffold for new cell-growth.

[0025] As also illustrated in Figure 2, some embodiments of the tissue interface 210 may comprise more than one layer. In the example of Figure 2, the tissue interface 210 comprises a first layer 220, a second layer 225, and a third layer 230. In some embodiments, the first layer 220 may be disposed adjacent to the second layer 225, and the third layer 230 may be disposed adjacent to the second layer 225 opposite the first layer 220. For example, the first layer 220, the second layer 225, and the third layer 230 may be stacked so that the first layer 220 is in contact with the second layer 225, and the second layer 225 is in contact with the first layer 220 and the third layer 230. One or more of the first layer 220, the second layer 225, and the third layer 230 may also be bonded to an adjacent layer in some embodiments. While the overall dressing 110, including the layers of the tissue interface 210, is shown in Figure 2 to have substantially a square shape, the dressing 110 and included layers may be any number of different shapes, based on the particular anatomical needs of a tissue site. For example, the dressing 110 and included layers may have a square, rectangular, oval, circular, hexagonal, or other shape. Additionally, the dressing 110 may further include three-dimensional forms that may be welded and shaped to address needs of specific types of tissue sites, such as breasts or post-amputation wounds.

[0026] The first layer 220 may be a contact layer or sealing layer comprising or consisting essentially of a soft, tacky material suitable for contacting and adhering to a tissue site, and may have a substantially flat surface. For example, the first layer 220 may comprise, without limitation, a silicone gel, a soft silicone, hydrocolloid, hydrogel, polyurethane gel, polyolefin gel, hydrogenated styrenic copolymer gel, a foamed gel, a soft closed cell foam such as polyurethanes and polyolefins coated with an adhesive, polyurethane, polyolefin, or hydrogenated styrenic copolymers. In some embodiments, the first layer 220 may be in the form of a film, and may have a thickness between about 200 microns (Mm) and about 1000 microns (Mm). In some embodiments, the first layer 220 may have a hardness between about 5 Shore OO and about 80 Shore OO. Further, the first layer 220 may be comprised of hydrophobic or hydrophilic materials.

[0027] In some embodiments, the first layer 220 may be a hydrophobic-coated material. For example, the first layer 220 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.

[0028] The first layer 220 may have a periphery 235 surrounding or around an interior portion 240, and apertures 245 disposed through the periphery 235. The interior portion 240 may correspond to a surface area of the second layer 225 in some examples. The first layer 220 may also have corners 250 and edges 255. The corners 250 and the edges 255 may be part of the periphery 235. The interior portion 240 of the first layer 220 may include a central aperture 260. In some embodiments, as illustrated in Figure 2, the central aperture 260 may be symmetrical and centrally disposed in the interior portion 240 of the first layer

220

[0029] The apertures 245 may be formed by cutting or by application of local RF or ultrasonic energy, for example, or by other suitable techniques for forming an opening. The apertures 245 may have a uniform distribution pattern, or may be randomly distributed on the first layer 220. The apertures 245 in the first layer 220 may have many shapes, including circles, squares, stars, ovals, polygons, slits, complex curves, rectilinear shapes, triangles, for example, or may have such combination of such shapes.

[0030] Each of the apertures 245 may have uniform or similar geometric properties. For example, in some embodiments, each of the apertures 245 may be circular apertures, having substantially the same diameter. In some embodiments, the diameter of each of the apertures 245 may be between about 1 millimeter to about 50 millimeters. In other embodiments, the diameter of each of the apertures 245 may be between about 1 millimeter to about 20 millimeters. In other embodiments, geometric properties of the apertures 245 may vary. For example, in some embodiments, the apertures 245 disposed in the periphery 235 may have a diameter between about 9.8 millimeters to about 10.2 millimeters. In some embodiments, the apertures 245 disposed in the corners 250 may have a diameter between about 7.75 millimeters to about 8.75 millimeters.

[0031] At least one of the apertures 245 in the periphery 235 of the first layer 220 may be positioned at the edges 255 of the periphery 235, and may have an interior cut open or exposed at the edges 255 that is in fluid communication in a lateral direction with the edges 255. The lateral direction may refer to a direction toward the edges 255 and in the same plane as the first layer 220. As shown in the example of Figure 2, the apertures 245 in the periphery 235 may be positioned proximate to or at the edges 255 and in fluid communication in a lateral direction with the edges 255. The apertures 245 positioned proximate to or at the edges 255 may be spaced substantially equidistant around the periphery 235 as shown in the example of Figure 2. Alternatively, the spacing of the apertures 245 proximate to or at the edges 255 may be irregular.

[0032] The second layer 225 may comprise or consist essentially of a means for controlling or managing fluid flow. In some embodiments, the second layer 225 may comprise or consist essentially of a liquid-impermeable, elastomeric material. For example, the second layer 225 may comprise or consist essentially of a non-porous polymer film. The second layer 225 may also have a smooth or matte surface texture in some embodiments. A glossy or shiny finish better or equal to a grade B3 according to the SPI (Society of the Plastics Industry) standards may be particularly advantageous for some applications. In some embodiments, variations in surface height may be limited to acceptable tolerances. For example, the surface of the second layer 225 may have a substantially flat surface, with height variations limited to 0.2 millimeters over a centimeter.

[0033] In some embodiments, the second layer 225 may be hydrophobic. The hydrophobicity of the second layer 225 may vary, but may have a contact angle with water of at least ninety degrees in some embodiments. In some embodiments, the second layer 225 may have a contact angle with water of no more than 150 degrees. For example, in some embodiments, the contact angle of the second layer 225 may be in a range of at least 90 degrees to about 120 degrees, or in a range of at least 120 degrees to 150 degrees. Water contact angles can be measured using any standard apparatus. Although manual goniometers can be used to visually approximate contact angles, contact angle measuring instruments can often include an integrated system involving a level stage, liquid dropper such as a syringe, camera, and software designed to calculate contact angles more accurately and precisely, among other things. Non-limiting examples of such integrated systems may include the FTA125, FTA200, FTA2000, and FTA4000 systems, all commercially available from First Ten Angstroms, Inc., of Portsmouth, VA, and the DTA25, DTA30, and DTA100 systems, all commercially available from Kruss GmbH of Hamburg, Germany. Unless otherwise specified, water contact angles herein are measured using deionized and distilled water on a level sample surface for a sessile drop added from a height of no more than 5 cm in air at 20- 25°C and 20-50% relative humidity. Contact angles reported herein represent averages of 5- 9 measured values, discarding both the highest and lowest measured values. The hydrophobicity of the second layer 225 may be further enhanced with a hydrophobic coating of other materials, such as silicones and fluorocarbons, either as coated from a liquid or plasma coated.

[0034] The second layer 225 may also be suitable for welding to other layers. For example, the second layer 225 may be adapted for welding to other film layers 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.

[0035] The area density of the second layer 225 may vary according to a prescribed therapy or application. In some embodiments, an area density of less than 40 grams per square meter may be suitable, and an area density of about 20-30 grams per square meter may be particularly advantageous for some applications.

[0036] In some embodiments, for example, the second layer 225 may comprise or consist essentially of a hydrophobic polymer, such as a polyethylene film. The simple and inert structure of polyethylene can provide a surface that interacts little, if any, with biological tissues and fluids, providing a surface that may encourage the free flow of liquids and low adherence, which can be particularly advantageous for many applications. Other suitable polymeric films include polyurethanes, acrylics, polyolefin (such as cyclic olefin copolymers), polyacetates, polyamides, polyesters, copolyesters, PEBAX block copolymers, thermoplastic elastomers, thermoplastic vulcanizates, polyethers, polyvinyl alcohols, polypropylene, polymethylpentene, polycarbonate, styreneics, silicones, fluoropolymers, and acetates. A thickness between 20 microns and 100 microns may be suitable for many applications. Films may be clear, colored, or printed. More polar films suitable for laminating to a polyethylene film include polyamide, copolyesters, ionomers, and acrylics. To aid in the bond between a polyethylene and polar film, tie layers may be used, such as ethylene vinyl acetate, or modified polyurethanes. An ethyl methyl acrylate (EM A) film may also have suitable hydrophobic and welding properties for some configurations.

[0037] As illustrated in the example of Figure 2, the second layer 225 may have one or more fluid restrictions 270, which can be distributed uniformly or randomly across the second layer 225. The fluid restrictions 270 may be bi-directional and pressure-responsive. For example, each of the fluid restrictions 270 generally may comprise or consist essentially of an elastic passage through the second layer 225 that is normally unstrained to substantially reduce liquid flow, and can expand or open in response to a pressure gradient. In some embodiments, the fluid restrictions 270 may comprise or consist essentially of perforations in the second layer 225. Perforations may be formed by removing material from the second layer 225. For example, perforations may be formed by cutting through the second layer 225, which may also deform the edges of the perforations in some embodiments. In the absence of a pressure gradient across the perforations, the passages may be sufficiently small to form a seal or fluid restriction, which can substantially reduce or prevent liquid flow. Additionally or alternatively, one or more of the fluid restrictions 270 may be an elastomeric valve that is normally closed when unstrained to substantially prevent liquid flow, and can open in response to a pressure gradient. A fenestration in the second layer 225 may be a suitable valve for some applications. Fenestrations may also be formed by removing material from the second layer 225, but the amount of material removed and the resulting dimensions of the fenestrations may be up to an order of magnitude less than perforations, and may result in edges that are not deformed. Additionally, in some embodiments, perforations may be formed by mechanical slitting then controlled uni- and/or bi-axial stretching of the film material of the second layer 225.

[0038] For example, some embodiments of the fluid restrictions 270 may comprise or consist essentially of one or more slits, slots, or combinations of slits and slots in the second layer 225. In some examples, the fluid restrictions 270 may comprise or consist of linear slots having a length less than 4 millimeters and a width less than 1 millimeter. The length may be at least 2 millimeters, and the width may be at least 0.4 millimeters in some embodiments. A length of about 3 millimeters and a width of about 0.5 millimeters may be particularly suitable for many applications, and a tolerance of about 0.1 millimeter may also be acceptable. Such dimensions and tolerances may be achieved with a laser cutter, ultrasonics, or other heat means, for example. The linear slits or slots may be spaced apart by about 2 to 4 millimeters along their length and from side-to-side. Slots of such configurations may function as imperfect valves that substantially reduce liquid flow in a normally closed or resting state. For example, such slots may form a flow restriction without being completely closed or sealed. The slots can expand or open wider in response to a pressure gradient to allow increased liquid flow.

[0039] In some embodiments, the fluid restrictions 270 are substantially coextensive with the second layer 225 and are distributed across the second layer 225 in a grid of parallel rows and columns, in which the slots are also mutually parallel to each other. In some embodiments, the rows may be spaced about 3 millimeters on center, and the fluid restrictions 270 within each of the rows may be spaced about 3 millimeters on center. The fluid restrictions 270 in adjacent rows may be aligned or offset. For example, adjacent rows may be offset so that the fluid restrictions 270 are aligned in alternating rows and separated by about 6 millimeters. The spacing of the fluid restrictions 270 may vary in some embodiments to increase the density of the fluid restrictions 270 according to therapeutic requirements.

[0040] The third layer 230 generally comprises or consists essentially of a manifold or a manifold area, which may include a plurality of pathways for distributing and/or collecting fluids. In some illustrative embodiments, a manifold may comprise or consist essentially of a porous material having interconnected fluid pathways. Examples of suitable porous material that can be adapted to form interconnected fluid pathways (e.g., channels) may include cellular foam, including open-cell foam such as reticulated foam; porous tissue collections; and other porous material such as gauze or felted mat that generally include pores, edges, and/or walls. Liquids, gels, and other foams may also include or be cured to include apertures and fluid pathways. In some embodiments, the third layer 230 may comprise or consist essentially of a reticulated foam having pore sizes and free volume that may vary according to needs of a prescribed therapy. For example, a reticulated foam having a free volume of at least 90% may be suitable for many therapy applications, and a foam having an average pore size in a range of 400-600 microns (40-50 pores per inch) may be particularly suitable for some types of therapy. The tensile strength of the third layer 230 may also vary according to needs of a prescribed therapy. For example, the tensile strength of a foam may be increased for instillation of topical treatment solutions. The 25% compression load deflection of the third layer 230 may be at least 0.35 pounds per square inch, and the 65% compression load deflection may be at least 0.43 pounds per square inch. In some embodiments, the tensile strength of the third layer 230 may be at least 10 pounds per square inch. The third layer 230 may have a tear strength of at least 2.5 pounds per inch. In some embodiments, the third layer 230 may be a foam comprised of polyols such as polyester or polyether, isocyanate such as toluene diisocyanate, and polymerization modifiers such as amines and tin compounds. In one non-limiting example, the third layer 230 may be a reticulated polyurethane ether foam such as used in GRANUFOAM™ dressing or V.A.C. VERAFLO™ dressing, both available from Kinetic Concepts, Inc. of San Antonio, Texas.

[0041] The third layer 230 may be either hydrophobic or hydrophilic. In an example in which the third layer 230 may be hydrophilic, the third layer 230 may also wick fluid away from a tissue site, while continuing to distribute negative pressure to the tissue site. The wicking properties of the third layer 230 may draw fluid away from a tissue site by capillary flow or other wicking mechanisms. An example of a hydrophilic material that may be suitable is a polyvinyl alcohol, open-cell foam such as V.A.C. WHITEFOAM™ dressing available from Kinetic Concepts, Inc. of San Antonio, Texas. Other hydrophilic foams may include those made from polyether. Other foams that may exhibit hydrophilic characteristics include hydrophobic foams that have been treated or coated to provide hydrophilicity.

[0042] The thickness of the third layer 230 may also vary according to needs of a prescribed therapy. For example, the thickness of the third layer 230 may be decreased to relieve stress on other layers and to reduce tension on peripheral tissue. The thickness of the third layer 230 can also affect the conformability of the third layer 230. In some embodiments, a thickness in a range of about 2 millimeters to about 10 millimeters may be suitable. In some embodiments, the third layer 230 may be partially or completely opaque, or otherwise be such that the third layer 230 may block at least a portion of light passage. Although not depicted in the example embodiment of Figure 2, in some embodiments, the third layer 230 may be sized and positioned so that the edges of the third layer 230 are placed inboard of the edges of the second layer 225.

[0043] Individual components of the tissue interface 210, and more generally the dressing 110, may be bonded or otherwise secured to one another with a solvent or non solvent adhesive, or with thermal welding, for example, without adversely affecting fluid management. Further, the second layer 225 or the third layer 230 of the tissue interface 210 may be coupled to the periphery 235 of the first layer 220 in any suitable manner, such as with a weld or an adhesive, for example.

[0044] In additional embodiments, the dressing 110 may be provided with different combinations of the individual layers and components. For example, the tissue interface 210 may be provided as a standalone product for applying to a tissue site. In some further embodiments, individual layers of the tissue interface 210 and the dressing 110 may be omitted.

[0045] In some embodiments, the cover 215 may provide a bacterial barrier and protection from physical trauma. The cover 215 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 215 may comprise or consist of, 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 215 may have a high moisture-vapor transmi sion rate (MVTR) in some applications. For example, the MVTR may be at least 250 grams per square meter per twenty-four hours in some embodiments, measured using an upright cup technique according to ASTM E96/E96M Upright Cup Method at 38°C and 10% relative humidity (RH). In some embodiments, an MVTR up to 5,000 grams per square meter per twenty-four hours may provide effective breathability and mechanical properties.

[0046] In some example embodiments, the cover 215 may be a polymer drape, such as a polyurethane film, that is permeable to water vapor but impermeable to liquid. Such drapes typically have a thickness in the range of 25-50 microns. For permeable materials, the permeability generally should be low enough that a desired negative pressure may be maintained. The cover 215 may comprise, for example, one or more of the following materials: polyurethane (PU), such as hydrophilic polyurethane; cellulosics; hydrophilic polyamides; polyvinyl alcohol; polyvinyl pyrrolidone; hydrophilic acrylics; silicones, such as hydrophilic silicone elastomers; natural rubbers; polyisoprene; styrene butadiene rubber; chloroprene rubber; polybutadiene; nitrile rubber; butyl rubber; ethylene propylene rubber; ethylene propylene diene monomer; chlorosulfonated polyethylene; polysulfide rubber; ethylene vinyl acetate (EVA); co-polyester; and polyether block polymide copolymers. Such materials are commercially available as, for example, Tegaderm® drape, commercially available from 3M Company, Minneapolis Minnesota; polyurethane (PU) drape, commercially available from Avery Dennison Corporation, Pasadena, California; polyether block polyamide copolymer (PEBAX), for example, from Arkema S.A., Colombes, France; and Inspire 2301 and Inpsire 2327 polyurethane films, commercially available from Expopack Advanced Coatings, Wrexham, United Kingdom. In some embodiments, the cover 215 may comprise INSPIRE 2301 having an MVTR (upright cup technique) of 2600 g/m²/24 hours and a thickness of about 30 microns.

[0047] In the example of Figure 2, the dressing 110 may further include an attachment device, such as an adhesive 275, which may be used to attach the cover 215 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 215 to epidermis around a tissue site. In some embodiments, for example, some or all of the cover 215 may be coated with an adhesive, such as an acrylic adhesive, which may have a coating weight of about 25-65 grams per square meter (g.s.m.). Thicker adhesives, or combinations of adhesives, may be applied in some embodiments to improve the seal and reduce leaks. In some embodiments, such a layer of the adhesive 275 may be continuous or discontinuous. Discontinuities in the adhesive 275 may be provided by apertures or holes (not shown) in the adhesive 275. The apertures or holes in the adhesive 275 may be formed after application of the adhesive 275 or by coating the adhesive 275 in patterns on a carrier layer such as a side of the cover 215. Other example embodiments of an attachment device may include a double sided tape, paste, hydrocolloid, hydrogel, silicone gel, or organogel. As also illustrated in the example of Figure 2, in some embodiments, the cover 215 may include an aperture 280 to provide a fluid path between the tissue interface 210 and a fluid conductor and/or a dressing interface for providing fluid connection to a negative-pressure source.

[0048] The cover 215, the first layer 220, the second layer 225, and the third layer 230, or various combinations may be assembled before application or in situ. For example, the cover 215 may be laminated to portions of the third layer 230 and the first layer 220, and the second layer 225 may be laminated to the third layer 230 opposite the cover 215 in some embodiments. The first layer 220 may also be coupled to the second layer 225 opposite the third layer 230 in some embodiments. In some embodiments, one or more layers of the tissue interface 210 may be coextensive. For example, the third layer 230 may be coextensive with the second layer 225, as illustrated in the embodiment of Figure 2. In some embodiments, the dressing 110 may be provided as a single, composite dressing. For example, the first layer 220 may be coupled to the cover 215 to enclose the second layer 225 and the third layer 230, wherein the first layer 220 is configured to face a tissue site.

[0049] As illustrated in the example of Figure 2, in some embodiments, the release layer 120 of the pouch 105 may include a first perimeter 287 that may be heat-sealed to a second perimeter 289 of the package layer 130 to provide a fluidly- sealed compartment for containing the dressing 110. In some embodiments, an additional attachment mechanism, such as one or more adhesive materials, may be applied to either or both of the first perimeter 287 of the release layer 120 and the second perimeter 289 of the package layer 130 to assist with providing a sealed envelope around the dressing 110.

[0050] The release layer 120 may serve as a protective material, or release liner, for protecting a tacky surface of the dressing 110 during storage and prior to use. For example, in the example embodiment of Figure 2, the release layer 120 may protect the exposed, outer tacky surface of the first layer 220 that is intended to be applied to a tissue site. Additionally, in the example embodiment of Figure 2, the release layer 120 may also protect an adhesive, such as adhesive 275, which may be exposed through apertures, such as apertures 245, of the first layer 220 of the tissue interface 210. For example, the release layer 120 may protect any portion of the adhesive 275 coated on a portion of the cover 215 that may be exposed through the apertures 245 of the first layer 220 of the tissue interface 210 prior to use of the dressing 110

[0051] In some embodiments, the release layer 120 may be, for example, a transparent layer, and may be a multilayer film comprising a base film 292 coextruded with an inner layer 294. The material of the inner layer 294 may aid with heat sealing an inner surface of the release layer 120 to an inner surface of the package layer 130 around the dressing 110. In some embodiments, the base film 292 may comprise a polyamide or polyester film, and the inner layer 294 may comprise a low melting-point ionomer-type material. For example, in some embodiments, the inner layer 294 may comprise a Surlyn® material, commercially available from DuPont™. In some additional or alternative embodiments, the inner layer 294 may comprise a non-ionomer-type low-melting/softening point material, such as, for example, a COSEAL™ material, commercially available from The Dow Chemical Company. Such materials of the base film 292 and the inner layer 294 may be stable with silicone, such as that of the first layer 220 in some embodiments of the tissue interface 210, and other adhesives that may be used in one or more layers of the dressing 110. Stability with silicone may ensure that a plasticizer from the materials of the release layer 120 will not leach and degrade the silicone or other materials of the one or more layers of the dressing 110 during a shelf-life period of the dressing kit 100. For example, it is unlikely that a silicone adhesive of one or more of the layers of the dressing 110 will contain components that are compatible with the polymeric materials of the inner layer 294 and base film 292 of the release layer 120, thus preventing any impetus for mobile materials in such a silicone adhesive from migrating into the release layer 120.

[0052] In some example embodiments, the release layer 120 may be in the form of a transparent film layer of a commercially- available pouch suitable for tissue dressings. For example, the release layer 120 may be the transparent film layer of a Tyvek® pouch commercially available from DuPont Corp., of Wilmington, DE, USA. In some alternative embodiments, the release layer 120 may be transparent within the first perimeter 287 of the release layer 120, and the first perimeter 287 may include a reinforcement material around the border of the release layer 120.

[0053] In some additional embodiments, a release agent may be disposed on an inner side of the release layer 120 that is configured to contact the first layer 220 of the tissue interface 210. For example, the release agent may have a release factor suitable to facilitate removal of the release layer 120 by hand and without damaging or deforming the first layer 220 of the tissue interface 210 or any other layers or compounds of the dressing 110. In some embodiments, the release agent may be a fluorocarbon or a fluorosilicone, for example.

[0054] The package layer 130 may comprise a material suitable for forming a seal, such as a heat seal, with at least a portion of the release layer 120. For example, the package layer 130 may be a material for forming a seal between a perimeter portion of the package layer 130 and a perimeter portion of the release layer 120, for example between the first perimeter 287 of the release layer 120 and the second perimeter 289 of the package layer 130. For example, the package layer 130 may comprise a paper-based material, such as that included as part of a commercially- available Tyvek® dressing pouch. In some embodiments, the package layer 130 may comprise a multi-layer film, which may comprise materials such as copolyesters and polyolefins. While the package layer 130 may be substantially opaque in some embodiments, additional embodiments may include a package layer 130 that has at least some degree of transparency.

[0055] In some embodiments of the dressing kit 100, one or more components of the dressing 110 or pouch 105 may additionally be treated with an antimicrobial agent. For example, the first layer 220, the second layer 225, and the third layer 230 of the tissue interface 210 may be coated with an antimicrobial agent. In some embodiments, the second layer 225 may comprise a polymer coated or mixed with an antimicrobial agent. In other examples, the cover 215, or in some instances a fluid conductor and/or dressing interface, or other portion of the dressing 110 may additionally or alternatively be treated with one or more antimicrobial agents. Additionally, at least a portion of the inner surfaces of either or both of the release layer 120 and the package layer 130 may be treated with an antimicrobial agent. Suitable antimicrobial agents may include, for example, metallic silver, PHMB, iodine or its complexes and mixes such as povidone iodine, copper metal compounds, chlorhexidine, or some combination of these materials. [0056] During use of the dressing kit 100, the release layer 120 may be removed to expose the first layer 220 of the tissue interface 210, which may be placed within, over, on, or otherwise proximate to a tissue site. For example, the first layer 220 may be placed over a surface wound (including the edges of the wound) and undamaged epidermis, wherein treatment of a surface wound or placement of the dressing 110 on a surface wound may include placing the dressing 110 immediately adjacent to the surface of the body or extending over at least a portion of the surface of the body. The periphery 235 of the first layer 220 may be positioned adjacent to or proximate to tissue around or surrounding the tissue site. The first layer 220 may be sufficiently tacky to hold the dressing 110 in position at the tissue site, while also allowing the dressing 110 to be removed or re-positioned without trauma to the tissue site. Removing the release layer 120 can also expose at least a portion of the adhesive 275 applied to an inner surface of the cover 215, and the cover 215 may be attached to an attachment surface. For example, the cover 215 may be attached to epidermis peripheral to a tissue site, around the third layer 230 and the second layer 225 of the tissue interface 210. The adhesive 275 may be in fluid communication with an attachment surface through the apertures 245 in at least the periphery 235 of the first layer 220 in some embodiments. The adhesive 275 may also be in fluid communication with the edges 255 through the apertures 245 exposed at the edges 255. Once the dressing 110 is in the desired position, the adhesive 275 may be pressed through the apertures 245 to bond or seal the dressing 110 to the attachment surface. In some embodiments, the apertures 245 of the first layer 220 may be sized to control the amount of the adhesive 275 that passes through the apertures 245. The apertures 245 at the edges 255 of the first layer 220 may permit the adhesive 275 to flow around the edges 255 for enhancing the adhesion of the edges 255 to an attachment surface. Additionally, in some embodiments, the bond strength of the adhesive 275 may vary in different locations of the dressing 110.

[0057] The geometry and dimensions of the tissue interface 210, the cover 215, or both may vary to suit a particular application or anatomy. For example, the geometry or dimensions of the tissue interface 210 and the cover 215 may be adapted to provide an effective and reliable seal against challenging anatomical surfaces, such as an elbow or heel, at and around a tissue site. Further, the tissue interface 210 may permit re-application or re positioning to correct air leaks caused by creases and other discontinuities in the dressing 110, for example. [0058] If not already configured, a dressing interface may be disposed over the aperture 280 of the cover 215 and attached to the cover 215. In some embodiments, for example, a dressing interface may facilitate coupling a fluid conductor to the dressing 110. For example, such a dressing interface may be a SENSAT.R.A.C.™ Pad available from Kinetic Concepts, Inc. of San Antonio, Texas. A fluid conductor may be fluidly coupled to the dressing interface and to a negative-pressure source. 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. In some embodiments, a dressing interface in the form of an elbow connector may be placed over the aperture 280 in the cover 215 at the time of application of the dressing 110 to a tissue site, and the dressing interface may be fluidly connected to the fluid conductor, which may be a flexible tube. In some embodiments, the fluid conductor may also include a fluid delivery conduit for use with instillation therapy. Further, in some embodiments, the dressing interface may include multiple fluid conduits, such as a conduit for communicating negative pressure and a fluid delivery conduit. For example, the dressing interface may be a V.A.C. VERAT.R.A.C.™ Pad. Although not shown in Figure 2, in some embodiments, a dressing interface and a fluid conductor may be included as part of the dressing kit 100. For example, a dressing interface and a fluid conductor may be positioned between the cover 215 of the dressing 110 and the package layer 130 so as to be contained within the pouch 105 of the dressing kit 100 prior to use.

[0059] Negative pressure applied through the tissue interface 210 can create a negative pressure differential across the fluid restrictions 270 in the second layer 225, which can open or expand the fluid restrictions 270 from their resting state. For example, in some embodiments in which the fluid restrictions 270 may comprise substantially closed fenestrations through the second layer 225, a pressure gradient across the fenestrations can strain the adjacent material of the second layer 225 and increase the dimensions of the fenestrations to allow liquid movement through them, similar to the operation of a duckbill valve. Opening the fluid restrictions 270 can allow exudate and other liquid movement through the fluid restrictions 270 and through the third layer 230. Changes in pressure can also cause the third layer 230 to expand and contract, and the second layer 225 and the first layer 220 may protect the epidermis from irritation caused by the movement of the third layer 230. The first layer 220 and the second layer 225 can also substantially reduce or prevent exposure of tissue to the third layer 230, which can inhibit growth of tissue into the third layer 230. If the supply of negative pressure is discontinued, the pressure differential across the fluid restrictions 270 can dissipate, allowing the fluid restrictions 270 to move to their resting state and prevent or reduce the rate at which exudate or other liquid can return to the tissue site through the second layer 225 of the tissue interface 210.

[0060] Figure 3 is an assembly view of another example of a dressing kit 100, illustrating additional details that may be associated with some embodiments. In the example embodiment of Figure 3, the dressing kit 100 may comprise an example embodiment of the tissue interface 210 of Figure 2, and the release layer 120 and package layer 130 of the pouch 105 of Figure 1. The tissue interface 210 of Figure 3 may comprise a first layer 310 and a second layer 320 disposed adjacent to the first layer 310. For example, the first layer 310 and the second layer 320 may be stacked so that the first layer 310 and the second layer 320 are in contact with each other.

[0061] The first layer 310 may be a contact layer or sealing layer comprising or consisting essentially of a soft, tacky material suitable for being placed in contact with a tissue site and potentially providing a fluid seal with a tissue site, and may have a substantially flat surface. For example, the first layer 310 may comprise, without limitation a silicone gel, a soft silicone, hydrocolloid, hydrogel, polyurethane gel, polyolefin gel, hydrogenated styrenic copolymer gel, a foamed gel, a soft closed cell foam such as polyurethanes and polyolefins coated with an adhesive, polyurethane, polyolefin, or hydrogenated styrenic copolymers. Further, the first layer 310 may be comprised of hydrophobic or hydrophilic materials. In some embodiments, the first layer 310 may be a hydrophobic-coated material. For example, the first layer 310 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 some embodiments, the first layer 310 may have similar dimensions to the first layer 220 of Figure 2. In some embodiments, the first layer 310 may be in the form of a square or rectangular ring comprising a central aperture 330. In some embodiments, as illustrated in Figure 3, the central aperture 330 may be symmetrical and centrally disposed in the first layer 310.

[0062] The second layer 320 may be substantially similar to the second layer 225 of the example embodiment of Figure 2, and may comprise or consist essentially of a means for controlling or managing fluid flow. In some embodiments, the second layer 320 may comprise or consist essentially of a non-porous polymer film having a plurality of fluid restrictions 340, which may be distributed across the second layer 320. As shown in Figure 3, the plurality of fluid restrictions 340 may be coextensive with the second layer 320.

[0063] Similar to the example dressing kit 100 of Figure 2, the release layer 120 and the package layer 130 in the example shown in Figure 3 may be sealed to each other to form the fluidly- sealed pouch 105 around the example tissue interface 210. For example, a first perimeter 287 of the release layer 120 may be sealed to a second perimeter 289 of the package layer 130. In the embodiment of Figure 3, the release layer 120 may be positioned adjacent to the first layer 310 of the tissue interface 210. The release layer 120 may also serve as a liner material for a tacky surface of the first layer 310 during the shelf-life of the dressing kit 100 prior to use of the tissue interface 210. Also similar to the dressing kit 100 of Figure 2, the package layer 130 of the example dressing kit 100 of Figure 3 may comprise a substantially non-transparent paper-based material suited for being positioned against the second layer 320 of the tissue interface 210 of Figure 3.

[0064] At the time of application of the tissue interface 210 of Figure 3, the second perimeter 289 of the package layer 130 may be peeled away from the first perimeter 287 of the release layer 120, and the package layer 130 may be removed from the tissue interface 210, thus leaving the tissue interface 210 with the release layer 120 adhered to the first layer 310 of the tissue interface 210. Thus, the release layer 120 may continue to serve as a protective liner over a tacky surface of the first layer 310 of the tissue interface 210 following the removal of the package layer 130. The user, such as a caregiver, may then subsequently peel away the release layer 120 to expose the tacky outer surface of the first layer 310 so that the first layer 310 may be placed in contact with a tissue site. The release layer 120 and the package layer 130 may be discarded as would normally be done with the pouch, release liners, and any other packaging components associated with the storage of a tissue dressing.

[0065] Figure 4 is an assembly view of another example of a dressing kit 100, illustrating additional details that may be associated with some embodiments. In the example embodiment of Figure 4, the dressing kit 100 may comprise an example embodiment of the dressing 110, the release layer 120, and the package layer 130 of the pouch 105 of Figure 1. The dressing 110 may comprise a tissue interface 210, which may comprise a first layer 410 and a second layer 420 disposed adjacent to the first layer 410. For example, the first layer 410 and the second layer 420 may be stacked so that the first layer 410 and the second layer 420 are in contact with each other. The first layer 410 may be in the form of a contact layer for being positioned against a tissue site. In some embodiments, the first layer 410 may comprise a siliconized substrate gauze, which may be laminated to the second layer 420, which may comprise an absorbent material. For example, in some embodiments, the second layer 420 may be in the form of a hydrophilic liquid-absorbent layer of textile material. In other embodiments, the second layer 420 may comprise a sheet of water-absorbent hydrophilic polyurethane foam, which may be capable of absorbing wound fluid while remaining bonded to the siliconized substrate gauze of the first layer 410. The dressing 110 may further include a cover 215, which may be in the form of a liquid-impermeable backing sheet. For example, the cover 215 of Figure 4 may comprise a polyurethane semipermeable backing sheet. A layer of adhesive 275 may be provided on a tissue-facing surface of the cover 215. For example, the adhesive 275 may be a polyurethane pressure-sensitive adhesive in some embodiments.

[0066] In the example embodiment shown in Figure 4, the dressing 110 may be in the form of an island dressing, which may describe the arrangement where a surface of the second layer 420 may have a smaller area than the area of the adjacent surface of the first layer 410. Accordingly, the second layer 420 may not be coextensive with the first layer 410 when positioned adjacent or against the first layer 410. In some embodiments, the dressing 110 may include a second layer 420 that is positioned against a central portion of the first layer 410. In the embodiment shown in Figure 4, since the area of the second layer 420 is less than that of the first layer 410 or the cover 215, a margin of the cover 215 may extend around all edges of the second layer 420. Therefore, a portion of the siliconized gauze of the first layer 410 may be directly bonded to an inner surface of the cover 215 over a margin of the cover 215, as well as to a tissue-facing surface of the second layer 420. This bonding of the siliconized gauze of the first layer 410 to the margin of the cover 215 may help to keep the absorbent island of the second layer 420 in place on the cover 215, and may also provide the margin of the cover 215 with a skin-friendly, weakly adherent (tacky) siliconized surface for contact with the skin around a tissue site. Such island-style dressings may be less prone to leakage of fluids from a tissue site from the edges of the dressing 110 than some other conventional wound dressings in the field. In some additional or alternative embodiments, the siliconized gauze of the first layer 410 may be coterminous with the absorptive island of the second layer 420 so that the margin of the cover 215 is solely adhesive-coated to provide adhesion to skin around a tissue site.

[0067] Similar to the example dressing kits of Figures 2 and 3, a first perimeter 287 of the release layer 120 and the second perimeter 289 of the package layer 130 may be sealed to each other to form a fluidly-sealed pouch around the dressing 110 of Figure 4. For example, the release layer 120 may be positioned adjacent to the first layer 410 for serving as a protective release liner material for the tacky siliconized gauze material of the first layer 410 prior to use of the dressing 110. The package layer 130 may comprise a substantially non transparent paper-based layer suited for being positioned against the cover 215 of the dressing 110.

[0068] Figure 5 is a schematic diagram providing some additional details of the embodiment of the dressing kit 100 of Figure 4. Specifically, Figure 5 shows the dressing 110 of Figure 4 within the release layer 120 and the package layer 130 of the pouch 105, which form an envelope or package around the dressing 110. Figure 5 further illustrates how during use of the dressing kit 100 of Figure 4, corners of the release layer 120 and the package layer 130 may be peeled away from each other to remove the release layer 120 and the package layer 130 from the dressing 110. Once the release layer 120 is removed from the first layer 410 of the dressing 110, the tacky surfaces of the siliconized gauze of the first layer 410 may be exposed for placement against a tissue site. Portions of the adhesive 275 applied to the margin of the cover 215 may also be exposed around the absorbent island of the second layer 420 and through the apertures in the siliconized gauze of the first layer 410. The release layer 120 and the package layer 130 of the pouch 105 may be discarded.

[0069] The example embodiments of the dressing kit 100 discussed herein may be formed and/or assembled according to a variety of manufacturing procedures, some of which may include multiple assembly stages. For example, in some illustrative embodiments, if the dressing 110 is not already in assembled form, the one or more layers of the dressing 110 may be first assembled at a first assembly stage. The dressing 110 may then be placed centrally on the internal surface of the release layer 120, which may be a substantially transparent film layer. At another assembly stage, the package layer 130, which may comprise a substantially opaque paper-based material, may be applied over the dressing 110, such as over an external surface of the cover 215 of the dressing 110. A peripheral weld may then be made between the perimeter of the release layer 120 and the perimeter of the package layer 130 to seal the pouch 105 in order to contain the dressing 110. In some additional or alternative embodiments, the pouch 105 of the dressing kit 100 may be provided as a single packaging sheet that may comprise two sections, one of which is a transparent material for providing the release layer 120 and the other of which is the paper-based material for providing the package layer 130. In such embodiments, during assembly of the dressing kit 100, the dressing 110 may first be placed centrally on the internal surface of the first section of the single packaging sheet for providing the release layer 120, and the second section of the single packaging sheet for providing the package layer 130 may then be folded over on top of the dressing 110. The peripheral portions of the first section forming the release layer 120 and the second section forming the package layer 130 may then be welded together to seal the pouch 105 around the dressing 110.

[0070] Figures 6A-6D are schematic diagrams illustrating some aspects of the use of a dressing kit 100, according to some example embodiments. More specifically, Figure 6 A shows an initial state 605 of a dressing kit 100, which may include a tissue interface 210 provided within a sealed pouch 105. For example, in this example, the tissue interface 210 may include a first layer 610 comprising a perforated silicone film laminated to a second layer 615 comprising a foam. In the initial sealed state of the dressing kit 100, as shown in the initial state 605, the first layer 610 may be adhered to the inner surface of a release layer 120 of the pouch 105.

[0071] Figure 6B shows a first opening step 620, where a user may begin to remove the tissue interface 210 from the pouch 105. More specifically, the user may peel the release layer 120 away from the package layer 130 to open the pouch 105 of the dressing kit 100 in order to access the tissue interface 210. As shown in Figure 6B, as the pouch 105 is opened, the first layer 610 of the tissue interface 210 remains adhered to the release layer 120, with the second layer 615 remaining exposed as the tissue interface 210 is pulled away from the package layer 130 with the release layer 120.

[0072] Figure 6C illustrates an open state 630 of the dressing kit 100, which is now shown with the package layer 130 having been removed, as discussed above. As depicted in the figure, the tissue interface 210 may remain attached to the release layer 120 via the adherence of the first layer 610 to the release layer 120, with the foam material of the second layer 615 exposed facing upwards. [0073] Figure 6D shows a second opening step 640, where the user may remove the tissue interface 210 from the release layer 120 of the dressing kit 100. As shown in Figure 6D, the user may begin removing the tissue interface 210 by peeling a comer or one side of the tissue interface 210 away from the release layer 120 of the pouch 105. In this example embodiment, the silicone material of the first layer 610 may allow the tissue interface 210 to be readily peeled away from the inner surface of the release layer 120, without tearing of either of the tissue interface 210 or the release layer 120. The first layer 610 of the tissue interface 210 may now be exposed and be ready to be applied to a tissue site of a patient. The layers of the pouch 105 of the dressing kit 100 may then be discarded in accordance with typical disposal procedures.

[0074] The example embodiments of the dressing kit 100 described above and illustrated in the accompanying figures are for illustrative purposes, and it should be understood that the dressing kit concepts disclosed herein could be employed with a variety of different dressings or features. Examples of the dressing 110 having layers or components with a range of different adhesive properties could be incorporated in the example embodiments of the dressing kit 100. Additionally, some embodiments of the dressing kit 100 may include one or more pull tabs, which may be used as grab handles, to facilitate separating the dressing 110 from at least one of the layers of the pouch 105 of the dressing kit 100. For example, a tab may be incorporated under the edge of the dressing 110 between the dressing 110 and the release layer 120 to facilitate separating the dressing 110 from the film of the release layer 120. This tab may then be subsequently removed from the dressing 110 during the application of the dressing 110 to the tissue site by the user.

[0075] The dressing kit 100 may in some instances be used as part of, or in conjunction with, therapy systems configured to deliver negative pressure therapy to one or more tissue sites. For example, a dressing kit 100 may be used for supplying the dressing or dressing material that is applied to the tissue site for use with a negative-pressure therapy system. Since it is often desirable for dressings to include a tacky tissue-facing surface, the disclosed packaging layers of the dressing kit 100 may protect such tacky surfaces prior to application to the tissue site and use with the negative-pressure therapy system.

[0076] Figure 7 is a simplified functional block diagram of an example embodiment of a therapy system 700 that can provide negative-pressure therapy to a tissue site in accordance with this specification. The therapy system 700 may include a source or supply of negative pressure, such as a negative-pressure source 705, and one or more distribution components. A distribution component is preferably detachable and may be disposable, reusable, or recyclable. A dressing, such as dressing 110, and a fluid container, such as a container 715, are examples of distribution components that may be associated with some examples of the therapy system 700. As illustrated in the example of Figure 7, the dressing 110 may comprise or consist essentially of a tissue interface 210, a cover 215, or both in some embodiments. The container 715 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.

[0077] The therapy system 700 may also include a regulator or controller, such as a controller 730. Additionally, the therapy system 700 may include sensors to measure operating parameters and provide feedback signals to the controller 730 indicative of the operating parameters. As illustrated in Figure 7, for example, the therapy system 700 may include a first sensor 735 and a second sensor 740 coupled to the controller 730.

[0078] Some components of the therapy system 700 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 705 may be combined with the controller 730 and other components into a therapy unit.

[0079] In general, components of the therapy system 700 may be coupled directly or indirectly. Coupling may include fluid, mechanical, thermal, electrical, or chemical coupling (such as a chemical bond), or some combination of coupling in some contexts.

[0080] A negative-pressure supply, such as the negative-pressure source 705, may be a reservoir of air at a negative pressure or may be a manual or electrically-powered device, such as a vacuum pump, a suction pump, a wall suction port available at many healthcare facilities, or a micro-pump, for example. “Negative pressure” generally refers to a pressure less than a local ambient pressure, such as the ambient pressure in a local environment external to a sealed therapeutic environment. In many cases, the local ambient pressure may also be the atmospheric pressure at which a tissue site is located. Alternatively, the pressure may be less than a hydrostatic pressure associated with tissue at the tissue site. Unless otherwise indicated, values of pressure stated herein are gauge pressures. References to increases in negative pressure typically refer to a decrease in absolute pressure, while decreases in negative pressure typically refer to an increase in absolute pressure. While the amount and nature of negative pressure provided by the negative-pressure source 705 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).

[0081] A controller, such as the controller 730, may be a microprocessor or computer programmed to operate one or more components of the therapy system 700, such as the negative-pressure source 705. The controller 730 may control one or more operating parameters of the therapy system 700, which may include the power applied to the negative- pressure source 705, the pressure generated by the negative-pressure source 705, or the pressure distributed to the tissue interface 210, for example. The controller 730 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.

[0082] Sensors, such as the first sensor 735 and the second sensor 740, are generally known in the art as any apparatus operable to detect or measure a physical phenomenon or property, and generally provide a signal indicative of the phenomenon or property that is detected or measured. For example, the first sensor 735 and the second sensor 740 may be configured to measure one or more operating parameters of the therapy system 700. In some embodiments, the first sensor 735 may be a transducer configured to measure pressure in a pneumatic pathway and convert the measurement to a signal indicative of the pressure measured. The second sensor 740 may optionally measure operating parameters of the negative-pressure source 705, such as a voltage or current, in some embodiments.

[0083] In operation, the tissue interface 210 may be placed within, over, on, or otherwise proximate to a tissue site. If the tissue site is a wound, for example, the tissue interface 210 may partially or completely fill the wound, or it may be placed over the wound. The cover 215 may be placed over the tissue interface 210 and sealed to an attachment surface near a tissue site. For example, the cover 215 may be sealed to undamaged epidermis peripheral to a tissue site. Thus, the dressing 110 can provide a sealed therapeutic environment proximate to a tissue site, substantially isolated from the external environment, and the negative-pressure source 705 can reduce pressure in the sealed therapeutic environment. Negative pressure applied across the tissue site through the tissue interface 210 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 715.

[0084] The systems, apparatuses, and methods described herein may provide significant advantages. For example, the dressing kits disclosed herein may provide for simplified means of storing a tissue dressing, and eliminate the need for separate, secondary release liners interior to a package or storage pouch.

[0085] Eliminating release liners may also improve usability at the time of dressing application. For example, eliminating interior release liners can reduce uncertainty and prevent a dressing from being applied to a tissue site with release liners inadvertently still adhered to the dressing. Furthermore, since the process of opening a pouch is typically familiar to users, the improved package designs of the disclosed dressing kits present few if any changes or risks to proper usability. Additionally, since at least one layer of the pouch of the disclosed dressing kits may be adhered to a surface of the dressing, there is reduced risk of the dressing falling from the pouch during opening of the pouch and becoming contaminated, thus requiring disposal. As a result, by simplifying the packaging of dressings, wasted time and potential error and waste due to contamination of dressings during application may be reduced or avoided. Such simplification may be particularly advantageous with tissue dressings having a tacky surface or adhesive that may have otherwise needed to be protected with a release liner prior to use.

[0086] Other benefits associated with the improved packaging designs of the disclosed dressing kits may be improved protection of the dressing or dressing materials during transportation or storage of the dressing materials. For example, since the dressing product may be fixed firmly within the dressing package or pouch, movement within the package may be prevented, thus reducing potential damage.

[0087] Additionally, the improved package designs disclosed herein may reduce or eliminate waste associated with dressings or dressing materials. For example, a dressing with integrated packaging can eliminate waste associated with release liners following application of a dressing. In addition to reducing the amount of waste material associated with packaging of each tissue dressing, significant savings may be realized due to eliminating the material cost of the additional release liners as well as the assembly costs associated with applying the release liners to the dressings. As a result, the material cost associated with each packaged dressing or dressing material may be reduced, which may allow tissue dressings to be offered more competitively in the market. Accordingly, the improved packaging designs associated with the disclosed dressing kits may improve usability and reduce risk of improper use, reduce the amount of waste material, and provide monetary savings as potentially compared to other commercially-available tissue dressings.

[0088] 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, dressing kit 100, the container 115, or any of the other disclosed components may be separated from other components for manufacture or sale. In other example configurations, the controller 130 may also be manufactured, configured, assembled, or sold independently of other components.

[0089] 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 kit for treating a tissue site, comprising:

a dressing comprising a contact layer having a tacky surface;

a release layer positioned against the tacky surface of the contact layer; and a package layer positioned adjacent a surface of the contact layer opposite the tacky surface;

wherein the release layer and the package layer are joined around a perimeter of the dressing to provide a sterile compartment around the dressing.

2. The kit of claim 1, wherein the contact layer comprises a hydrophobic gel.

3. The kit of claim 1, wherein the contact layer comprises a hydrophobic gel having a plurality of apertures.

4. The kit of claim 1, further comprising a cover layer positioned between the contact layer and the package layer and comprising a polymer drape.

5. The kit of claim 4, wherein the cover layer comprises an adhesive disposed on a first side of the cover layer.

6. The kit of claim 3, further comprising:

a cover layer positioned between the contact layer and the package layer and

comprising a polymer drape having an adhesive disposed on a first side of the cover layer;

wherein at least a portion of the adhesive extends through at least some of the plurality of apertures of the contact layer.

7. The kit of claim 4, further comprising a polymer film positioned between the contact layer and the cover layer.

8. The kit of claim 7, wherein the polymer film has a plurality of fluid restrictions.

9. The kit of claim 4, further comprising a manifold layer positioned between the contact layer and the cover layer.

10. The kit of claim 9, wherein the dressing does not comprise a separate release liner.

11. The kit of claim 9, wherein the manifold layer comprises reticulated polyurethane ether foam.

12. The kit of claim 4, further comprising:

a film layer positioned between the contact layer and the cover layer and

comprising a polymer film; and

a manifold layer positioned between the film layer and the cover layer.

13. The kit of claim 1, wherein the release layer comprises:

an outer film layer comprising a transparent material; and

an inner layer comprising a material adapted to assist with heat sealing a perimeter edge of the release layer to a perimeter edge of the package layer.

14. The kit of claim 13, wherein the inner layer comprises a low-melting-point ionomer material.

15. The kit of claim 1, wherein the release layer is adapted to be peeled away from the tacky surface of the contact layer.

16. The kit of claim 2, wherein the hydrophobic gel comprises a silicone gel.

17. The kit of claim 1, wherein the package layer comprises a polyolefin material.

18. A dressing kit, comprising:

a dressing comprising a first surface and a second surface, wherein the first surface is tacky; and

an envelope, comprising:

a first envelope layer coupled to the first surface of the dressing and adapted to protect the first surface, and

a second envelope layer positioned adjacent the second surface of the dressing, wherein the first envelope layer and the second envelope layer are joined

around a perimeter of the dressing to provide a sealed, sterile compartment around the dressing.

19. The dressing kit of claim 18, wherein the first surface comprises a hydrophobic gel.

20. The dressing kit of claim 19, wherein the hydrophobic gel has a plurality of apertures.

21. The dressing kit of claim 19, wherein the second surface comprises a polymer drape, and an adhesive is disposed between the polymer drape and the hydrophobic gel.

22. The dressing kit of claim 19, wherein:

the hydrophobic gel has a plurality of apertures;

the dressing further comprises an adhesive disposed between the second surface and the hydrophobic gel; and

at least a portion of the adhesive is exposed through at least some of the plurality of apertures.

23. The dressing kit of claim 21, further comprising a polymer film disposed between the polymer drape and the hydrophobic gel, the polymer film having a plurality of fluid restrictions.

24. The dressing kit of claim 21, further comprising:

a polymer film positioned between the hydrophobic gel and the polymer drape, the polymer film having a plurality of fluid restrictions; and a manifold positioned between the polymer film and the polymer drape.

25. The dressing kit of claim 24, wherein the manifold comprises foam.

26. The dressing kit of claim 25, wherein the foam is a reticulated polyurethane ether foam.

27. The dressing kit of claim 18, wherein the first envelope layer comprises:

an outer film layer comprising a transparent material; and

an inner layer comprising a material adapted to assist with heat sealing a perimeter edge of the first envelope layer to a perimeter edge of the second envelope layer.

28. The dressing kit of claim 27, wherein the inner layer comprises a low-melting-point ionomer material.

29. The dressing kit of claim 18, wherein the first envelope layer is adapted to be peeled away from the first surface of the dressing.

30. The dressing kit of claim 22, wherein the first envelope layer is adapted to protect both the first surface of the dressing and the at least a portion of the adhesive exposed through the apertures prior to use of the dressing and to be peeled away from the first surface.

31. The dressing kit of claim 18, wherein the second envelope layer comprises a polyolefin material.

32. The dressing kit of claim 19, wherein the hydrophobic gel comprises a silicone gel.

33. The dressing kit of claim 24, wherein the polymer drape comprises a margin that extends beyond the polymer film and the manifold.

34. The dressing kit of claim 23, wherein the polymer film is hydrophobic.

35. The dressing kit of claim 23, wherein the polymer film is a polyurethane film.

36. The dressing kit of claim 21, wherein the dressing further comprises a fluid port adapted to be coupled to the second surface, the fluid port configured to be coupled to a fluid conductor.

37. A dressing kit, comprising:

a dressing, comprising:

a first layer comprising a hydrophobic gel,

a second layer comprising a polymer film, and

a third layer coupled to the second layer opposite the first layer, the third layer comprising a polymer drape having an adhesive disposed on a first side; and

a pouch, comprising:

a release layer coupled to the first layer opposite the second layer, wherein the release layer is adapted to be peeled away from the first layer, and a package layer positioned adjacent the third layer;

wherein a perimeter edge of the release layer and a perimeter edge of the

package layer are joined so that the pouch forms a sealed compartment around the dressing.

38. The dressing kit of claim 37, wherein the release layer comprises:

an outer film layer comprising a transparent material; and

an inner layer comprising a material adapted to assist with heat sealing the perimeter edge of the release layer to the perimeter edge of the package layer.

39. The dressing kit of claim 38, wherein the inner layer comprises a low-melting point ionomer material.

40. The dressing kit of claim 37, wherein the first layer comprises a plurality of apertures.

41. The dressing kit of claim 37, wherein the second layer further comprises a plurality of fluid restrictions configured to expand in response to a pressure gradient across the polymer film.

42. The dressing kit of claim 37, wherein the dressing further comprises a fourth layer positioned between the second layer and the third layer and comprising a manifold.

43. The dressing kit of claim 42, wherein the first layer and the third layer of the dressing enclose the second layer and the fourth layer.

44. The dressing kit of claim 37, wherein the hydrophobic gel of the first layer comprises a silicone gel.

45. The dressing kit of claim 42, wherein the polymer drape comprises a margin that extends beyond the second layer and the fourth layer.

46. The dressing kit of claim 42, wherein the manifold comprises foam.

47. The dressing kit of claim 46, wherein the foam is a reticulated polyurethane ether foam.

48. The dressing kit of claim 42, wherein the manifold has a thickness of less than 7 mm.

49. The dressing kit of claim 37, wherein the polymer film of the second layer is hydrophobic.

50. The dressing kit of claim 37, wherein the polymer film of the second layer is a polyurethane film.

51. The dressing kit of claim 41, wherein the fluid restrictions comprise a plurality of slots, each of the slots having a length less than 4 mm.

52. The dressing kit of claim 37, wherein the package layer comprises a copolyester material.

53. The dressing kit of claim 37, wherein the dressing does not comprise a separate release liner adjacent to the first layer.

54. A method of manufacturing a packaged dressing, comprising:

assembling a plurality of dressing layers in a stack to form a dressing, wherein the plurality of dressing layers comprises a first layer comprising a tacky outer surface and a second layer comprising a polymer drape;

positioning the dressing on an internal surface of a first package layer by placing the tacky outer surface of the first layer in contact with a central portion of the first package layer;

positioning a second package layer on an outer surface of the second layer of the dressing layers; and

welding a perimeter of the first package layer to a perimeter of the second package layer to form a sealed pouch around the dressing.

55. The method of claim 54, wherein the first package layer comprises:

an outer film layer comprising a transparent material; and

an inner layer comprising a material adapted to assist with heat sealing the

perimeter of the first package layer to the perimeter of the second package layer.

56. The method of claim 55, wherein the inner layer comprises a low-melting point ionomer material.

57. The method of claim 54, wherein the first package layer is adapted to be peeled away from the tacky outer surface of the first layer.

58. The method of claim 54, wherein the second package layer comprises a polyolefin material.

59. The method of claim 54, wherein the first layer comprises a hydrophobic gel.

60. The method of claim 59, wherein the hydrophobic gel comprises a silicone gel.

61. The method of claim 54, wherein the dressing does not comprise a separate release liner adjacent to the first layer.

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