Negative pressure wound therapy devices and systems

Abstract

Apparatus and system for use in a negative pressure wound therapy environment. A dressing configured to be placed on a tissue site includes a first film layer, a manifold, and a cover layer. The first film layer includes a treatment region having a first plurality of perforations, a sealing region surrounding the treatment region having a second plurality of perforations, and a sealing adhesive covering the sealing region of the first surface of the first film layer configured to face the tissue site. The manifold is disposed adjacent to the second surface of the first film layer, the second surface being opposite the first surface. The cover layer is disposed over the manifold and is coupled to the second surface of the first film layer around the manifold. The cover layer includes a second film layer and a cover adhesive disposed adjacent to the second plurality of perforations.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit of priority of U.S. Provisional Application No. 63 / 349,375, filed on June 6, 2022, which is hereby incorporated by reference in its entirety.

[0002] The invention described in the appended claims generally relates to tissue treatment systems, and more specifically, but not limited to, dressings for tissue treatment by negative pressure and methods of using dressings for tissue treatment by negative pressure.

Background Art

[0003] Clinical research and clinical practice have shown that by reducing the pressure near a tissue site, the growth of new tissue at the tissue site can be enhanced and accelerated. Although there are many applications of this phenomenon, it has been proven to be particularly advantageous for treating wounds. Regardless of the cause of the wound, whether due to trauma, surgery, or another cause, appropriate care of the wound is important for the outcome. The treatment of wounds or other tissues by reducing pressure can generally be referred to as "negative pressure therapy", but is also known by other names, including, for example, "negative pressure wound therapy", "decompression therapy", "vacuum therapy", "vacuum - assisted closure", and "local negative pressure". Negative pressure therapy can provide many benefits, including the migration of epithelial and subcutaneous tissues, improvement of blood flow, and micro - deformation of tissues at the wound site. Overall, these benefits can enhance the development of granulation tissue and shorten the healing time.

[0004] The clinical benefits of negative pressure therapy are widely known, but improvements in therapy systems, components, and processes can benefit healthcare providers and patients.

Summary of the Invention

[0005] The appended claims describe a novel and useful system, apparatus, and method for treating tissue in a negative pressure therapy environment. Exemplary embodiments are also provided to enable one of ordinary skill in the art to make and use the claimed subject matter.

[0006] For example, in some embodiments, a dressing material for treating tissue can include a first film layer, a manifold, and a cover layer. The first film layer can include a treatment region and a sealing region surrounding the treatment region. The first film layer can further include a first plurality of perforations formed through the treatment region and a second plurality of perforations formed through the sealing region. The second plurality of perforations can be larger than the first plurality of perforations. The first film layer can further include a sealing adhesive that covers the sealing region of the first surface of the first film layer configured to face the tissue site. The manifold can be disposed adjacent to the second surface of the first film layer. The second surface of the first film layer can be opposite the first surface of the first film layer. The cover layer can include a second film layer and a cover adhesive. The cover layer can be disposed over the manifold and can be coupled to the second surface of the first film layer around the manifold. The cover adhesive can be disposed adjacent to the second plurality of perforations.

[0007] In some exemplary embodiments, the first film layer can include a polyurethane film having a thickness of from about 20 microns to about 35 microns.

[0008] In some exemplary embodiments, the sealing adhesive can include a silicone adhesive having a coating weight of from about 100 grams per square meter to about 250 grams per square meter.

[0009] In some exemplary embodiments, the manifold can include a closed-cell foam having a thickness of from about 5 millimeters to about 10 millimeters.

[0010] In some exemplary embodiments, the second film layer can include a polyurethane film having a thickness of from about 20 microns to about 35 microns.

[0011] In some exemplary embodiments, the cover adhesive can include an acrylic adhesive having a coating weight of from about 25 grams per square meter to about 65 grams per square meter.

[0012] In some exemplary embodiments, the cover adhesive can be configured to extend from the second surface of the first film layer to the first surface of the first film layer through a second plurality of perforations.

[0013] In some exemplary embodiments, the treatment region can be configured to contact the tissue site, and the sealing region can be configured to contact the epidermis around the tissue site.

[0014] In some exemplary embodiments, the treatment region can be configured such that the first surface of the first film layer in the treatment region is disposed in direct contact with the tissue site, and may not include an adhesive.

[0015] In some exemplary embodiments, the first plurality of perforations can include slits arranged in a pattern.

[0016] In some exemplary embodiments, the second plurality of perforations can include circular openings arranged in a pattern.

[0017] In some exemplary embodiments, each of the first plurality of perforations can include a first open area, and each of the second plurality of perforations can include a second open area that is larger than the first open area.

[0018] In some exemplary embodiments, the first plurality of perforations can include a shape different from that of the second plurality of perforations.

[0019] In some exemplary embodiments, the second plurality of apertures may be larger than the first plurality of apertures in at least one dimension.

[0020] In some exemplary embodiments, the first plurality of apertures may be configured to increase in size when the tissue site is exposed to pressure. The second plurality of apertures may not change in size when exposed to pressure. The second plurality of apertures may be larger in size than the first plurality of apertures when the tissue site is exposed to pressure and when the tissue site is not exposed to pressure.

[0021] In some exemplary embodiments, the dressing material may further include a carrier layer removably coupled to a surface of the cover layer opposite the cover adhesive. The carrier layer can include a coated paper or a polymer film.

[0022] Also described herein is an exemplary system for treating a tissue site with negative pressure therapy. The system can include a dressing material that can include a first film layer, a manifold, and a cover layer. The first film layer can include a treatment region and a sealing region surrounding the treatment region. The first film layer can further include a first plurality of apertures formed through the treatment region and a second plurality of apertures formed through the sealing region. The second plurality of apertures may be larger than the first plurality of apertures. The first film layer can further include a sealing adhesive that covers the sealing region of the first surface of the first film layer configured to face the tissue site. The manifold can be disposed adjacent to the second surface of the first film layer. The second surface of the first film layer can be opposite the first surface of the first film layer. The cover layer can include a second film layer and a cover adhesive. The cover layer can be disposed over the manifold and coupled to the second surface of the first film layer around the manifold. The cover adhesive can be disposed adjacent to the second plurality of apertures. The system can also include a negative pressure source configured to be fluidly coupled to the tissue site through the cover.

[0023] Also described herein is another exemplary system for treating a tissue site with negative pressure therapy. The system can include a dressing configured to be disposed adjacent to the tissue site. The dressing can include a first film layer, a manifold, and a second film layer. The first film layer can include a treatment region and a sealing region surrounding the treatment region. A plurality of slits may be formed through the treatment region, and a plurality of holes may be formed through the sealing region. The plurality of holes can have a larger open area than the plurality of slits. The first film layer can further include a sealing adhesive that covers the sealing region of the face of the first film layer configured to face the tissue site. The second film layer can include an opening. The face of the second film layer configured to face the tissue site of the second film layer may be coated with a pressure-sensitive adhesive. The carrier layer, the first film layer, the manifold, and the second film layer can be assembled in a stacked relationship with the first film layer and the second film layer wrapping the manifold. The manifold can be aligned with the treatment region. The pressure-sensitive adhesive and the sealing region can be configured to face the tissue site, and at least a portion of the pressure-sensitive adhesive may be exposed through the plurality of holes. The carrier layer can be laminated to the second film layer on the face of the second film layer opposite the pressure-sensitive adhesive. The negative pressure source can be configured to be fluidly coupled to the tissue site through the opening, the manifold, and the plurality of slits.

[0024] In some exemplary embodiments, the sealing adhesive is not disposed over the treatment region.

[0025] In some exemplary embodiments, the carrier layer can include a coated paper or a polymer film. The carrier layer may be removably attached to the second film layer and configured to be removed from the second film layer after the dressing is disposed adjacent to the tissue site.

[0026] In some exemplary embodiments, the sealing adhesive can be applied in a pattern to the first film layer. The sealing adhesive can be applied to the first film layer in a pattern such that the treatment area is free of the sealing adhesive. The sealing adhesive can be applied to the first film layer in a pattern such that the sealing area includes the sealing adhesive but the treatment area is free of the sealing adhesive.

[0027] The objects, advantages, and preferred aspects of the claimed subject matter can be best understood by reference to the accompanying drawings in conjunction with the following detailed description of the exemplary embodiments.

Brief Description of the Drawings

[0028]

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[0029] The following description of the exemplary embodiments provides information that enables those skilled in the art to make and use the subject matter recited in the appended claims, and certain details that are well known in the art may be omitted. Accordingly, the following detailed description should be construed as illustrative and not restrictive.

[0030] FIG. 1 is a block diagram of an exemplary embodiment of a therapy system 100 that can provide negative pressure therapy to a tissue site in accordance with this specification.

[0031] 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 surface wounds, bone tissue, adipose tissue, muscle tissue, nerve tissue, dermal tissue, vascular tissue, connective tissue, cartilage, tendon, or ligament. Examples of wounds can include, for example, chronic, acute, traumatic, subacute, and lacerated wounds, partial thickness burns, ulcers (such as diabetic ulcers, pressure ulcers, or venous insufficiency ulcers), skin flaps, and grafts. The term "tissue site" can also refer to any region of tissue that is not necessarily wounded or defective, but rather, is an area where additional tissue growth may be desired or promoted. For example, negative pressure can be applied to a tissue site to grow additional tissue that can be harvested and transplanted.

[0032] Therapy system 100 may include a negative pressure source or a negative pressure supply unit such as negative pressure source 105, and one or more distribution components. The distribution components are preferably separable and may be disposable, reusable, or recyclable. Dressing materials such as dressing material 110 and fluid containers such as container 115 are examples of distribution components that may be associated with some examples of therapy system 100. As illustrated in the example of FIG. 1, dressing material 110 may comprise, or consist essentially of, tissue interface 120, cover 125, or both in some embodiments.

[0033] A fluid conduit is another exemplary example of a distribution component. As used in this context, "fluid conduit" broadly includes tubes, pipes, hoses, conduits, or other structures having one or more lumens or open passages adapted to convey fluid between two ends. Typically, a tube is an elongated cylindrical structure having some flexibility, although the geometry and rigidity can vary. Further, some fluid conduits may be molded within other components or otherwise integrally combined with other components. The distribution component may also include, or be provided with, an interface or fluid port to facilitate connecting and disconnecting other components. In some embodiments, for example, a dressing interface may facilitate connecting a fluid conduit to dressing material 110. For example, such a dressing interface may be a SENSAT.R.A.C. (trademark) Pad available from 3M Company.

[0034] Therapy system 100 may also include a regulator or a controller such as controller 130. Additionally, therapy system 100 may include sensors for measuring operating parameters and providing a feedback signal indicative of the operating parameters to controller 130. As illustrated in FIG. 1, for example, therapy system 100 may include a first sensor 135 and a second sensor 140 coupled to controller 130.

[0035] Some components of the therapy system 100 may be housed within or used in conjunction with other components such as sensors, processing units, alarm indicators, memories, databases, software, display devices, or user interfaces that make the therapy easier. For example, in some embodiments, the negative pressure source 105 may be combined with the controller 130 and other components in the therapy unit 145.

[0036] Generally, the components of the therapy system 100 may be coupled directly or indirectly. For example, the negative pressure source 105 may be directly coupled to the container 115 and indirectly coupled to the dressing 110 through the container 115. In some contexts, couplings may include fluid couplings, mechanical couplings, thermal couplings, electrical couplings, or chemical couplings (such as chemical bonds), or some combinations thereof. For example, the negative pressure source 105 may be electrically coupled to the controller 130 and fluidly coupled to one or more distribution components to provide a fluid path to the tissue site. In some embodiments, components may also be coupled by physical proximity, by integrating them into a single structure, or by forming them from the same piece of material.

[0037] A negative pressure supply unit such as the negative pressure source 105 can be, for example, a reservoir of negative pressure air, or a manual or electrically driven device such as a vacuum pump, a suction pump, a wall suction port available in many medical facilities, or a micropump. "Negative pressure" generally refers to a pressure less than a local ambient pressure such as the ambient pressure in a local external environment relative to a sealed treatment environment. In many cases, the local ambient pressure can also be the atmospheric pressure at the location where the tissue site is located. Alternatively, the pressure can be less than the hydrostatic pressure associated with the tissue at the tissue site. Unless otherwise indicated, the pressure values described herein are gauge pressures. References to an increase in negative pressure typically refer to a decrease in absolute pressure, while a decrease in negative pressure typically refers to an increase in absolute pressure. The amount and nature of the negative pressure provided by the negative pressure source 105 can vary according to treatment requirements, but the pressure is generally a low vacuum, generally also referred to as a rough vacuum, of -5 mmHg (-667 Pa) to -500 mmHg (-66.7 kPa). A typical treatment range is -50 mmHg (-6.7 kPa) to -300 mmHg (-39.9 kPa).

[0038] The container 115 represents a container, canister, pouch, or other storage component that can be used to manage exudate and other fluids removed from the tissue site. In many environments, a rigid container may be preferred or required to collect, store, and discard the fluid. In other environments, the fluid can be appropriately discarded without being stored in a rigid container, but a reusable container can reduce the waste and costs associated with negative pressure therapy.

[0039] A controller, such as controller 130, can be a microprocessor or computer programmed to operate one or more components of therapy system 100, such as negative pressure source 105. In some embodiments, for example, controller 130 can be a microcontroller, which generally comprises an integrated circuit including a processor core and memory programmed to directly or indirectly control one or more operating parameters of therapy system 100. Operating parameters can include, for example, the power applied to negative pressure source 105, the pressure generated by negative pressure source 105, or the pressure distributed to tissue interface 120. Controller 130 is also preferably configured to receive one or more input signals, such as feedback signals, and is programmed to modify one or more operating parameters based on the input signals.

[0040] Sensors, such as first sensor 135 and second sensor 140, can be any device operable to detect or measure a physical phenomenon or property and generally can provide a signal indicative of the detected or measured phenomenon or property. For example, first sensor 135 and second sensor 140 can be configured to measure one or more operating parameters of therapy system 100. In some embodiments, first sensor 135 can be a transducer configured to measure the pressure in the pneumatic path and convert the measurement into a signal indicative of the measured pressure. In some embodiments, for example, first sensor 135 can be a piezoresistive strain gauge. In some embodiments, second sensor 140 can optionally measure an operating parameter of negative pressure source 105, such as voltage or current. Preferably, the signals from first sensor 135 and second sensor 140 are suitable as input signals to controller 130, although in some embodiments some signal conditioning can be appropriate. For example, the signals may need to be filtered or amplified before being processed by controller 130. Typically, the signals are electrical signals, although they can be represented in other forms, such as optical signals.

[0041] The tissue interface 120 can generally be adapted to partially or fully contact the tissue site. The tissue interface 120 can take many forms and can have many sizes, shapes, or thicknesses depending on various factors such as the type of treatment being performed, or the nature and size of the tissue site. For example, the size and shape of the tissue interface 120 can be adapted to the contour of a deeply irregularly shaped tissue site. Any or all of the surfaces of the tissue interface 120 can have a ridged, rough, or jagged profile.

[0042] In some embodiments, the tissue interface 120 can comprise or consist essentially of a manifold. A manifold in this context can comprise or consist essentially of means for collecting or distributing fluid across the tissue interface 120 under pressure. For example, the manifold can be adapted to receive negative pressure from a source and distribute the negative pressure through a plurality of openings across the tissue interface 120, which can have the effect of collecting fluid from the tissue site and drawing the fluid towards the source. In some embodiments, the fluid path can be reversed or a second fluid path can be provided to facilitate delivering fluid across the tissue site.

[0043] In some exemplary embodiments, the manifold may comprise a plurality of passages that can be interconnected to improve fluid distribution or recovery. In some exemplary embodiments, the manifold may include or consist essentially of a porous material having interconnected fluid passages. Examples of suitable porous materials that can be adapted to form interconnected fluid passages (e.g., channels) include cellular foams such as open-cell foams like reticulated foams, aggregates of porous tissue, and other porous materials such as gauze or felt-like mats generally including pores, edges, and / or walls. Liquids, gels, and other foams can also include or be cured to include openings and fluid passages. In some embodiments, the manifold may additionally or alternatively comprise protrusions that form interconnected fluid passages. For example, the manifold can be molded to provide surface protrusions that define interconnected fluid passages.

[0044] In some embodiments, the tissue interface 120 can include, or consist essentially of, an open-cell foam having a pore size and free volume that can vary according to the requirements of the indicated therapy. For example, an open-cell foam having at least 90% free volume can be suitable for many therapeutic applications, and for some types of therapy, a foam having an average pore size in the range of 400 - 600 microns (40 - 50 pores per inch) can be particularly suitable. The tensile strength of the tissue interface 120 can also vary according to the requirements of the indicated therapy. The 25% compression load deflection of the tissue interface 120 can be at least 0.35 pounds per square inch, and the 65% compression load deflection can be at least 0.43 pounds per square inch. In some embodiments, the tensile strength of the tissue interface 120 can be at least 10 pounds per square inch. The tissue interface 120 can have a tear strength of at least 2.5 pounds per inch. In some embodiments, the tissue interface can be a foam consisting of a polyol such as polyester or polyether, an isocyanate such as toluene diisocyanate, and a polymerization regulator such as an amine and tin compound. In some examples, the tissue interface 120 can be an open-cell polyurethane foam such as that found in both the GRANUFOAM™ dressing or the V.A.C. VERAFLO™ dressing, both available from the 3M Company.

[0045] The thickness of the tissue interface 120 can also vary according to the requirements of the indicated therapy. For example, the thickness of the tissue interface can be reduced to reduce the tension on the surrounding tissue. The thickness of the tissue interface 120 can also affect the conformity of the tissue interface 120. In some embodiments, a thickness in the range of about 5 millimeters to 10 millimeters can be appropriate.

[0046] The tissue interface 120 can be either hydrophobic or hydrophilic. In one example where the tissue interface 120 can be hydrophilic, the tissue interface 120 can also allow fluid to escape away from the tissue site while continuing to distribute negative pressure to the tissue site. The wicking properties of the tissue interface 120 can draw fluid away from the tissue site by capillary flow or other wicking mechanisms. One example of a suitable hydrophilic material is an open-cell foam of polyvinyl alcohol such as the V.A.C. WHITEFOAM (trademark) dressing material available from 3M Company. Other hydrophilic foams can include those made from polyethers. Other foams that can exhibit hydrophilic properties can include hydrophobic foams that are treated or coated to provide hydrophilicity.

[0047] In some embodiments, the tissue interface 120 can be constructed from a bioabsorbable material. Suitable bioabsorbable materials can include, but are not limited to, a polymer blend of polylactic acid (PLA) and polyglycolic acid (PGA). Polymer blends can also include, but are not limited to, polycarbonate, polyfumarate, and caprolactone. The tissue interface 120 can serve a further role as a scaffold for new cell growth, or a scaffold material can be used in conjunction with the tissue interface 120 to promote cell growth. A scaffold is generally a substance or structure used to enhance or promote cell growth or tissue formation, such as a three-dimensional porous structure that provides a template for cell growth. Exemplary examples of scaffold materials can include calcium phosphate, collagen, PLA / PGA, coral hydroxyapatite, carbonate, or processed allograft material.

[0048] In some embodiments, the cover 125 can provide protection from bacterial barriers and physical trauma. The cover 125 can also be constructed from a material that can reduce evaporative losses and provide a fluid seal between two components or between two environments such as between the treatment environment and the local external environment. The cover 125 can include, or consist of, for example, an elastic film or membrane that can provide a seal sufficient to maintain negative pressure at the tissue site with respect to a given source of negative pressure. In some applications, the cover 125 can have a high moisture-vapor transmission rate (MVTR). For example, the MVTR can be at least 250 grams / square meter / 24 hours when measured using the Upright Cup technique of ASTM E96 / E96M at 38 °C and 10% relative humidity (RH) in some embodiments. In some embodiments, an MVTR of up to 5000 grams / square meter / 24 hours can provide effective breathability and mechanical properties.

[0049] In some exemplary embodiments, the cover 125 can be a polymeric drape such as a polyurethane film that is permeable to water vapor but impermeable to liquids. Such a drape typically has a thickness in the range of 25 to 50 microns. With respect to the permeable material, the permeability should generally be low enough so that the desired negative pressure can be maintained. The cover 125 can include one or more of, for example, polyurethane (PU) such as hydrophilic polyurethane, cellulose derivatives, hydrophilic polyamides, polyvinyl alcohol, polyvinyl pyrrolidone, hydrophilic acrylics, silicones such as hydrophilic silicone elastomers, natural rubber, 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), copolyesters, and polyether block polyamide copolymers. Such materials are commercially available, for example, as polyurethane (PU) drapes from Avery Dennison Corporation (Pasadena, California), polyether block polyamide copolymers (PEBAX) such as those manufactured by Arkema S.A. (Colombes, France), and INSPIRE® 2301 and INSPIRE® 2327 polyurethane films commercially available from Exopack Advanced Coatings (Wrexham, United Kingdom). In some embodiments, the cover 125 can include INSPIRE® 2301 having an MVTR (upright cup technique) of 2600 g / m 2 / 24 hours and a thickness of about 30 microns.

[0050] An attachment device can be used to attach the cover 125 to an attachment surface such as an intact epidermis, gasket, or another cover. The attachment device can take many forms. For example, the attachment device can be a medically acceptable pressure-sensitive adhesive configured to bond the cover 125 to the epidermis around the tissue site. In some embodiments, for example, a portion or all of the cover 125 can be coated with an adhesive such as an acrylic adhesive that can have a coating weight of about 25 to 65 grams per square meter (g.s.m.). In some embodiments, a thicker adhesive, or combination of adhesives, can be applied to improve the seal and reduce leakage. Other exemplary embodiments of the attachment device can include double-sided tape, paste, hydrocolloid, hydrogel, silicone gel, or organogel.

[0051] During operation, the tissue interface 120 can be placed within, over, on, or otherwise proximate to the tissue site. For example, if the tissue site is a wound, the tissue interface 120 can partially or completely occlude the wound or be placed over the wound. The cover 125 can be placed over the tissue interface 120 and sealed to an attachment surface near the tissue site. For example, the cover 125 can be sealed to the intact epidermis surrounding the tissue site. Thus, the dressing 110 can provide a sealed treatment environment proximate to the tissue site that is substantially isolated from the external environment, and the negative pressure source 105 can reduce the pressure within the sealed treatment environment.

[0052] The process of reducing pressure can be illustratively described herein, for example, as "delivering," "distributing," or "generating" negative pressure.

[0053] Generally, exudate and other fluids flow along a fluid path toward a lower pressure. Thus, the term "downstream" typically refers to a position within the fluid path that is relatively closer to a negative pressure source or farther from a positive pressure source. Conversely, the term "upstream" refers to a position that is relatively farther from a negative pressure source or closer to a positive pressure source. Similarly, it may be convenient to describe features in relation to a fluid "inlet" or "outlet" in such a framework. This orientation is generally assumed for the purpose of describing the various features and components of this specification. However, the fluid path can also be reversed in some applications, such as by replacing a negative pressure source with a positive pressure source, and should not be construed limitedly by this illustrative convention.

[0054] Negative pressure applied to the tissue site through the tissue interface 120 within the sealed treatment environment can cause macro and micro distortions at the tissue site. The negative pressure can also remove exudate and other fluids from the tissue site, and the exudate and other fluids can be collected within the container 115.

[0055] In some embodiments, the controller 130 may receive and process data from one or more sensors, such as the first sensor 135. The controller 130 may also control the operation of one or more components of the therapy system 100 to manage the pressure delivered to the tissue interface 120. In some embodiments, the controller 130 may include an input for receiving a desired target pressure and may be programmed to process data regarding the setting and input of the target pressure applied to the tissue interface 120. In some exemplary embodiments, the target pressure may be a fixed pressure value that is set by an operator as the desired target negative pressure for therapy at the tissue site and is then provided as an input to the controller 130. The target pressure may vary depending on the type of tissue forming the tissue site, the type of injury or wound (if present), the patient's medical condition, and the preference of the attending physician. After selecting the desired target pressure, the controller 130 can operate the negative pressure source 105 in one or more control modes based on the target pressure and can receive feedback from one or more sensors to maintain the target pressure at the tissue interface 120.

[0056] FIG. 2 is an exploded view of an exemplary embodiment of the dressing 110 of FIG. 1, illustrating additional details that may be associated with some embodiments in which the tissue interface 120 includes two or more layers. In some embodiments, the tissue interface 120 may include a manifold 202 and a first film layer 204. The manifold 202 may include a first surface 206 and a second surface 208 opposite the first surface 206. The first film layer 204 may include a first surface 210 and a second surface 212 opposite the first surface 210. The first surface 210 of the first film layer 204 may be coupled to the second surface 208 of the manifold 202 such that the manifold 202 is stacked on top of the first film layer 204 when the dressing 110 is assembled.

[0057] The manifold 202 may comprise or consist essentially of a manifold or a manifold layer as described above with reference to FIG. 1, which provides means for collecting or distributing fluid across the tissue interface 120 under pressure. The manifold 202 may be an oval or stadium-shaped manifold in some embodiments. In some embodiments, the manifold 202 may be GRANUFOAM™ or an open-cell foam that may be about 5 millimeters to about 10 millimeters thick. The manifold 202 may be adapted to receive negative pressure from a source such as the negative pressure source 105 and distribute the negative pressure through a plurality of openings across the tissue interface 120, which may have the effect of collecting fluid from the tissue site and drawing the fluid toward the source. In some embodiments, the fluid path may be reversed or a second fluid path may be provided to facilitate delivering fluid across the tissue interface 120 from a source such as an infusion solution source.

[0058] The first film layer 204 may comprise or consist essentially of means for controlling or managing fluid flow. The first film layer 204 may include a peripheral portion 214 that can surround an inner portion 216. The inner portion 216 may be symmetrically disposed about the center of the first film layer 204. In some embodiments, the peripheral portion 214 may be a sealing region of the first film layer 204 and the inner portion 216 may be a treatment region of the first film layer 204. In some embodiments, the inner portion 216 may correspond to the surface area of the manifold 202. In some embodiments, a boundary 218 may divide or separate the inner portion 216 from the peripheral portion 214 of the first film layer 204. The first film layer 204 may further include corner portions 220 and edge portions 222 that may be part of the peripheral portion 214.

[0059] The first film layer 204 may further include a first plurality of perforations 226 formed through the inner portion 216 and a second plurality of perforations 228 formed through the peripheral portion 214. The first plurality of perforations 226 may be fluid restriction portions that can be bidirectional and pressure-responsive. The first plurality of perforations 226 may generally include or consist essentially of elastic passages that can expand in response to a pressure gradient. In some embodiments, the first plurality of perforations 226 may be formed by removing material from the first film layer 204. For example, the first plurality of perforations 226 may be formed by cutting the first film layer 204, which may also, in some embodiments, deform the edges of the first plurality of perforations 226. If there is no pressure gradient across the first plurality of perforations 226, the passages may be small enough to form a seal or flow restriction that can substantially reduce or prevent liquid flow. Additionally or alternatively, one or more of the first plurality of perforations 226 may be normally closed when not being pulled or under negative pressure so as to substantially prevent liquid flow, and can open in response to a pressure gradient, and may be an elastomeric valve.

[0060] In some embodiments, the first plurality of perforations 226 may include, or may consist essentially of, one or more slits or slots, or combinations of slits or slots, within the first film layer 204. In some examples, the first plurality of perforations 226 may include, or may consist of, linear slots having a length of less than 4 millimeters and a width of less than 1 millimeter. In some embodiments, the length may be at least 2 millimeters and the width may be at least 0.4 millimeters. A length of about 3 millimeters and a width of about 0.8 millimeters may be particularly suitable for many applications. A tolerance of about 0.1 millimeter may also be acceptable. Such dimensions and tolerances can be achieved, for example, using a laser cutter. Slots of such a configuration can function as an imperfect valve that substantially reduces liquid flow in a normally closed or stationary state. For example, such slots can form a flow restriction without being completely closed or sealed. The slots can expand or open wider in response to a pressure gradient and increase liquid flow.

[0061] In some embodiments, the first plurality of perforations 226 may be slits or slots arranged in a pattern. For example, the slits or slots may be arranged in a chevron pattern, a grid of parallel rows and columns, or another pattern. Alternatively, the first plurality of perforations 226 may be randomly distributed throughout the inner portion 216 of the first film layer 204.

[0062] The second plurality of perforations 228 may be disposed through the peripheral portion 214 of the first film layer 204. The second plurality of perforations 228 may be openings or holes that can be formed by cutting, applying local RF or ultrasonic energy, or other suitable techniques for forming openings. The second plurality of perforations 228 may have a uniform distribution pattern or may be randomly distributed throughout the peripheral portion 214 of the first film layer 204. The second plurality of perforations 228 may have many shapes, including, for example, circular, square, star-shaped, elliptical, polygonal, slotted, complex curves, linear shapes, triangles, or some combinations of such shapes.

[0063] Each of the second plurality of apertures 228 may have uniform or similar geometric characteristics. For example, in some embodiments, each of the second plurality of apertures 228 may be a circular opening having substantially the same diameter. In some embodiments, the diameter of each of the second plurality of apertures 228 may be from about 1 millimeter to about 50 millimeters. In other embodiments, the diameter of each of the second plurality of apertures 228 may be from about 1 millimeter to about 20 millimeters.

[0064] In other embodiments, the geometric characteristics of the second plurality of apertures 228 may vary. For example, the diameter of the second plurality of apertures 228 may vary depending on the location of the second plurality of apertures 228. In some embodiments, the second plurality of apertures 228 disposed at the corners 220 may have a diameter from about 7.75 millimeters to about 8.75 millimeters, and the remainder of the second plurality of apertures 228 may have a diameter from about 9.8 millimeters to about 10.2 millimeters.

[0065] At least one of the second plurality of apertures 228 may be disposed at the edge 222 of the peripheral portion 214 and may have an internal cutout that is open or exposed at the edge 222 and is in lateral fluid communication with the edge 222. The lateral direction may refer to a direction towards the edge 222 and that is in the same plane as the first film layer 204. The second plurality of apertures 228 disposed adjacent to or at the edge 222 may be substantially equidistantly spaced around the peripheral portion 214. Alternatively, the spacing of the second plurality of apertures 228 adjacent to or at the edge 222 may be irregular.

[0066] In some embodiments, each of the first plurality of apertures 226 may have a first open area, and each of the second plurality of apertures 228 may have a second open area. Each second open area may be larger than each first open area. Similarly, each of the second plurality of apertures 228 may be larger than each of the first plurality of apertures 226 in at least one dimension. As described above, each of the first plurality of apertures 226 may be pressure-responsive, and thus each of the first plurality of apertures 226 may be configured to increase in size when the tissue site is exposed to a pressure such as a negative pressure from the negative pressure source 105. In contrast, the second plurality of apertures 228 may not change in size when exposed to pressure. Further, the second plurality of apertures 228 may be larger in size than the first plurality of apertures 226 when the tissue site is exposed to pressure and when the tissue site is not exposed to pressure.

[0067] In some embodiments, the first film layer 204 may further include a sealing adhesive 230. The sealing adhesive 230 may be disposed on the second surface 212 of the first film layer 204 such that when the dressing 110 is placed on the tissue site, the sealing adhesive 230 faces the tissue site and contacts the area around the wound of the tissue site. The sealing adhesive 230 may be disposed on the peripheral portion 214 and may not be disposed on the inner portion 216 of the first film layer 204. The sealing adhesive 230 may be applied to the first film layer 204 in a pattern such that there is no sealing adhesive 230 on the inner portion 216. In some embodiments, the sealing adhesive 230 may be or may include a coating of a silicone material. Suitable silicone adhesives are described, for example, in U.S. Patent Application Publication No. 2011 / 0212325, which is incorporated herein by reference. In some embodiments, silicone oils such as Dow's OHX4070 and Wacker's AK1,000,000 may be included in the sealing adhesive 230. In some embodiments, the sealing adhesive 230 may have a coating weight of from about 100 grams per square meter to about 250 grams per square meter.

[0068] The first film layer 204 can include or consist essentially of a film that can have a substantially flat surface that can provide a fluid seal with the tissue site. In some embodiments, the first film layer 204 can be a polyurethane film such as Pellethane® 5863-86A (Lubrizol). In some embodiments, the first film layer 204 can be about 20 microns to about 35 microns thick. In some embodiments, the first film layer 204 can further include an adhesive on a first surface 210 of the first film layer 204. The adhesive on the first surface 210 can adhere the first film layer 204 to the cover 125 and / or the manifold 202. The adhesive on the first surface 210 of the first film layer 204 can include any of the materials described above for the attachment device with reference to FIG. 1.

[0069] The dressing material 110 may further include a second film layer such as the cover 125. The cover 125 may include a first surface 232 and a second surface 234 opposite the first surface 232. The second surface 234 of the cover 125 may be configured to bond to the first surface 206 of the manifold 202 of the tissue interface 120. The cover 125 may include or consist essentially of a polyurethane film such as Pellethane® 5863-86A (Lubrizol). In some embodiments, the cover 125 may have a thickness of from about 20 microns to about 35 microns. The dressing material 110 may further include an attachment device such as the attachment device described above with reference to FIG. 1, or a cover adhesive or adhesive 236. The adhesive 236 may be, for example, a medically acceptable pressure-sensitive adhesive that extends around the perimeter, part, or whole of the second surface 234 of the cover 125. In some embodiments, for example, the adhesive 236 may be an acrylic adhesive having a coating weight of from about 25 g.s.m. to about 65 g.s.m. In some embodiments, a thicker adhesive, or combination of adhesives, may be applied to improve the seal and reduce leakage. The adhesive 236 may be a layer having substantially the same shape as the peripheral portion 214 of the first film layer 204. In some embodiments, the adhesive 236 may be continuous or discontinuous. The discontinuous portions of the adhesive 236 may be provided by openings or holes (not shown) in the adhesive 236. The openings or holes in the adhesive 236 may be formed after applying the adhesive 236 or by applying the adhesive 236 in a pattern on the second surface 234 of the cover 125. The openings or holes in the adhesive 236 may also be sized in some exemplary embodiments to improve the MVTR of the dressing material 110.

[0070] As illustrated in the example of FIG. 2, in some embodiments, the release liner 240 can be attached to or disposed adjacent to the first film layer 204 to protect the adhesive 236 prior to use. The release liner 240 can also provide rigidity, for example, to assist in the deployment of the dressing material 110. The release liner 240 can be, for example, kraft paper, a film, or polyethylene. Further, in some embodiments, the release liner 240 can be a polyester material such as polyethylene terephthalate (PET) or a similar polar semi-crystalline polymer. The use of a polar semi-crystalline polymer for the release liner 240 can substantially eliminate wrinkles or other deformations of the dressing material 110. For example, the polar semi-crystalline polymer can be highly oriented and have resistance to softening, swelling, or other deformations that can occur when contacted with components of the dressing material 110, or when subjected to changes in temperature or environment, or when sterilized. In some embodiments, the release liner 240 can have a surface texture that can be imprinted on an adjacent layer such as the first film layer 204. In some embodiments, the release liner 240 can be a Scotchpak (trademark) fluoropolymer-coated release liner (3M). Further, a release agent can be disposed on the surface of the release liner 240 configured to contact the first film layer 204. For example, the release agent can be a silicone coating and can have a release element suitable for facilitating the removal of the release liner 240 by hand without damaging or deforming the dressing material 110. In some embodiments, the release agent can be, for example, a fluorocarbon or fluorosilicone. In other embodiments, the release liner 240 may not be coated or may be used otherwise without a release agent.

[0071] In some embodiments, the dressing material 110 may further include a carrier 242. The carrier 242 may include a first surface 244 and a second surface 246 opposite the first surface 244. The second surface 246 of the carrier 242 may be configured to couple to the first surface 232 of the cover 125. In some embodiments, the carrier 242 may be removably coupled to the first surface 232 of the cover 125. In some embodiments, the carrier 242 may be laminated to the first surface 232 of the cover 125. The carrier 242 may enable stable handling after the release liner 240 is removed from the dressing material 110. In some embodiments, the carrier 242 may have a first elongated portion 248 and a second elongated portion 250 connected by a connection portion 252. The carrier 242 may have a different shape or size in some embodiments, but may still provide a structure for the dressing material 110 after the release liner 240 is removed. The carrier 242 may be composed of a coated paper or film in some embodiments. An example of a carrier material may include a polyethylene / vinyl acetate copolymer coated kraft paper available from Loparex.

[0072] In some embodiments, the dressing material 110 may further include any handling bar (not shown). Any handling bar may provide a place for a healthcare provider or user to hold the dressing material 110 while applying it to the tissue site. In some embodiments, any handling bar may be coupled to the adhesive 236 of the cover 125. In other embodiments, any handling bar may be located at different locations on the dressing material 110.

[0073] FIG. 2 also illustrates an exemplary embodiment of a fluid conduit 256 and a dressing interface 258. The fluid conduit 256 can be a flexible tube that can fluidly couple one end to the dressing interface 258. The dressing interface 258 can be an elbow connector, and the elbow connector can be placed through an opening 260 in a carrier 242 that can surround an opening 262 in the cover 125. The opening 262 can provide a fluid path between the fluid conduit 256 and the tissue interface 120 of the dressing 110.

[0074] In use, the release liner 240 (if included) may be removed to expose the first film layer 204, and the first film layer 204 can be placed over, on, or otherwise adjacent to the tissue site, particularly the surface tissue site and the adjacent epidermis. The first film layer 204 can be interposed between the manifold 202 and the tissue site and can substantially reduce or eliminate detrimental interactions with the manifold 202. For example, the first film layer 204 can be placed over surface wounds (including wound edges) and uninjured epidermis to prevent direct contact with the manifold 202. Treating a surface wound or placing the dressing 110 on a surface wound includes placing the dressing 110 directly adjacent to the body surface or extending over at least a portion of the body surface. Treating a surface wound does not include placing the dressing 110 completely inside the body, such as placing the dressing in the peritoneal cavity, or completely under the body surface. In some applications, the inner portion 216 of the first film layer 204 can be placed adjacent to, proximate to, or over the tissue site. The peripheral portion 214 of the first film layer 204 can be placed adjacent to or proximate to the tissue surrounding or surrounding the tissue site. The first film layer 204 can be sufficiently adhesive to hold the dressing 110 in place and can also allow the dressing 110 to be removed or repositioned without trauma to the tissue site.

[0075] By removing the release liner 240, the adhesive 236 of the cover 125 can also be exposed to the tissue site. For example, the cover 125 can be attached to the epidermis around the tissue site, around the manifold 202. The adhesive 236 can be in fluid communication with the attachment surface through at least the second plurality of perforations 228 within at least the peripheral portion 214 of the first film layer 204 in some embodiments. The adhesive 236 can also be in fluid communication with the edge 222 through the second plurality of perforations 228 exposed at the edge 222.

[0076] When the dressing 110 comes to the desired position, the adhesive 236 can be pressed through the second plurality of perforations 228 to join the dressing 110 to the attachment surface. The second plurality of perforations 228 at the edge 222 can allow the adhesive 236 to flow around the edge 222 and strengthen the adhesion of the edge 222 to the attachment surface.

[0077] In some embodiments, the second plurality of perforations 228 within the first film layer 204 can be sized to control the amount of adhesive 236 that is in fluid communication with the attachment surface through the second plurality of perforations 228. For a given geometric shape of the corner 220, the relative sizes of the second plurality of perforations 228 can be configured to maximize the surface area of the adhesive 236 that is exposed and in fluid communication through the second plurality of perforations 228 at the corner 220. For example, the edges 222 can intersect at substantially right angles or about 90 degrees to define the corner 220. In some embodiments, the corner 220 can have a radius of about 10 millimeters. Further, in some embodiments, three of the second plurality of perforations 228 having a diameter of from about 7.75 millimeters to about 8.75 millimeters can be arranged in a triangular configuration at the corner 220 to maximize the exposed surface area for the adhesive 236. In other embodiments, the sizes and number of the second plurality of perforations 228 at the corner 220 can be adjusted as needed according to the selected geometric shape of the corner 220 to maximize the exposed surface area of the adhesive 236. Further, the second plurality of perforations 228 at the corner 220 can be completely contained within the first film layer 204, substantially eliminating lateral fluid communication external to the corner 220. The second plurality of perforations 228 at the corner 220 that are completely contained within the first film layer 204 can substantially prevent fluid communication of the adhesive 236 external to the corner 220 and can provide improved handling of the dressing 110 during deployment at the tissue site. Further, the exterior of the corner 220 that is substantially free of the adhesive 236 can increase the flexibility of the corner 220 to enhance comfort.

[0078] In some embodiments, the bonding strength of the adhesive 236 can vary at different positions of the dressing material 110. For example, the adhesive 236 can have a lower bonding strength at the location of the first film layer 204 where the second plurality of perforations 228 are relatively large, and can have a higher bonding strength where the second plurality of perforations 228 are smaller. The adhesive 236 having a lower bonding strength combined with the larger second plurality of perforations 228 can provide a bond comparable to that of the adhesive 236 having a higher bonding strength at a location having smaller second plurality of perforations 228, and can provide a substantially uniform overall bond along the peripheral portion 214 of the second surface 212 of the first film layer 204.

[0079] The geometric shape and dimensions of the tissue interface 120, the cover 125, or both can vary to conform to a particular application or biological structure. For example, the geometric shape or dimensions of the tissue interface 120 and the cover 125 can be adapted to provide an effective and secure seal against difficult anatomical surfaces such as the elbow or heel at and around the tissue site. Additionally or alternatively, the dimensions can be modified to increase the surface area of the first film layer 204 in order to enhance the movement and proliferation of epithelial cells at the tissue site and reduce the likelihood of granulation tissue ingrowth.

[0080] Furthermore, the dressing material 110 can allow for reapplication or repositioning to reduce or eliminate leaks that can be caused by folds and other discontinuities in the dressing material 110 and at the tissue site. The ability to correct leaks can, in some embodiments, increase the reliability of the therapy and reduce power consumption.

[0081] Thus, the dressing material 110 in the example of FIG. 2 can provide a sealed treatment environment proximate to a tissue site substantially isolated from the external environment, and the negative pressure source 105 can reduce the pressure within the sealed treatment environment. The first film layer 204 can provide an effective and secure seal against difficult anatomical surfaces, such as elbows or heels, at and around the tissue site. Further, the dressing material 110 can allow for reapplication or repositioning, for example, to correct for air leakage caused by folds and other discontinuities in the dressing material 110. The ability to correct for leakage can, in some embodiments, enhance the effectiveness of the therapy and reduce power consumption.

[0082] If not already configured, the dressing material interface 258 can be disposed over the opening 262 and attached to the cover 125. The fluid conduit 256 can be fluidly coupled to the dressing material interface 258 and the negative pressure source 105.

[0083] The negative pressure applied through the tissue interface 120 can create a negative pressure differential across the first plurality of apertures 226 within the first film layer 204, which can open or expand the first plurality of apertures 226 from their resting state. For example, in some embodiments where the first plurality of apertures 226 can comprise substantially closed fenestrations through the first film layer 204, the pressure gradient across the fenestration can distort the adjacent material of the first film layer 204, similar to the operation of a duckbill valve, to increase the dimensions of the fenestration and allow liquid movement through the fenestration. By opening the first plurality of apertures 226, exudate and other liquids can be allowed to move through the first plurality of apertures 226 into the manifold 202 and the container 115. The change in pressure can also expand and contract the manifold, and the border 218 can protect the epidermis from irritation. The first film layer 204 can also substantially reduce or prevent tissue exposure to the manifold 202 and inhibit tissue growth into the manifold 202.

[0084] In some embodiments, the manifold 202 can be hydrophobic to minimize the retention or storage of liquid within the dressing 110. In other embodiments, the manifold 202 can be hydrophilic. In one example where the manifold 202 can be hydrophilic, the manifold 202 can also allow fluid to escape away from the tissue site while continuing to distribute negative pressure to the tissue site. The wicking properties of the manifold 202 can draw fluid away from the tissue site, for example, by capillary flow or other wicking mechanisms. One example of a hydrophilic manifold 202 is a continuous bubble foam of polyvinyl alcohol such as the V.A.C. WHITEFOAM™ dressing available from KCI (San Antonio, Texas). Other hydrophilic foams can include those made from polyethers. Other foams that can exhibit hydrophilic properties can include hydrophobic foams that are treated or coated to provide hydrophilicity.

[0085] When the negative pressure source 105 is removed or turned off, the pressure differential across the first plurality of apertures 226 can dissipate, allowing the first plurality of apertures 226 to move to their resting state and preventing or reducing the rate at which exudate or other liquid returns to the tissue site through the first film layer 204.

[0086] Additionally or alternatively, an infusion solution or other fluid can be dispensed into the dressing 110, which can increase the pressure within the tissue interface 120. When the pressure within the tissue interface 120 increases, a positive pressure differential can be generated across the first plurality of apertures 226 within the first film layer 204, which can open or expand the first plurality of apertures 226 from their resting state and allow the infusion solution or other fluid to be dispensed to the tissue site.

[0087] Figure 3 is an assembly view of the dressing material 110 of FIG. 2. When the dressing material 110 is assembled, the second surface 234 of the cover 125 can be coupled to the first surface 206 of the manifold 202, the second surface 208 of the manifold 202 can be coupled to the first surface 210 of the first film layer 204, and the second surface 212 of the first film layer 204 can be coupled to the release liner 240. The release liner 240 can be removed from the second surface 212 of the first film layer 204 before the dressing material 110 is placed at the tissue site. In some embodiments, the carrier 242 can be removed from the dressing material 110 after the dressing material is placed on the tissue site and before the dressing material interface 258 is attached to the first surface 232 of the cover 125 of the dressing material 110.

[0088] The individual components of the dressing material 110 can be joined or otherwise affixed to each other, for example, using a solvent or non-solvent adhesive or using heat welding, without adversely affecting fluid management. Further, the manifold 202 can be coupled to the boundary 218 of the first film layer 204 by any suitable method such as welding or an adhesive.

[0089] The cover 125, the manifold 202, the first film layer 204, or various combinations can be assembled before application or in situ. For example, in some embodiments, the cover 125 can be laminated to the manifold 202. The first film layer 204 can also be coupled to the manifold 202 on the opposite side of the cover 125 in some embodiments. In some embodiments, the dressing material 110 can be provided as a single composite dressing material. For example, the first film layer 204 may be coupled to the cover 125 so as to surround the manifold 202, and the first film layer 204 is configured to face the tissue site.

[0090] Referring to FIGS. 4A and 4B, the first film layer 204 of the tissue interface 120 is shown. FIG. 4A is a top view of the first film layer 204, and FIG. 4B is a bottom view of the first film layer 204. The first film layer 204 may include a peripheral portion 214, an inner portion 216, and a boundary 218 that can surround the inner portion 216 and can divide or separate the inner portion 216 from the peripheral portion 214. The sealing adhesive 230 may be disposed on the second surface 212 of the first film layer 204. The sealing adhesive 230 may be disposed on the peripheral portion 214 and may not be disposed on the inner portion 216 of the first film layer 204. The sealing adhesive 230 may be applied to the first film layer 204 such that the inner portion 216 does not include the sealing adhesive 230 and the sealing adhesive 230 surrounds each of the second plurality of perforations 228. In some embodiments, the sealing adhesive 230 may be applied to the first film layer 204 in a pattern. Further, in some embodiments, the sealing adhesive 230 may be applied to the peripheral portion 214 of the second surface 212 of the first film layer 204, and then the first plurality of perforations 226 and / or the second plurality of perforations 228 are formed through the first film layer 204. In some exemplary embodiments, the sealing adhesive 230 may be a layer that may have a partial notch corresponding to the inner portion 216 of the first film layer 204. Then, the sealing adhesive 230 may be laminated on the second surface 212 of the first film layer 204. The first plurality of perforations 226 may be formed through the inner portion 216 of the first film layer 204, and the second plurality of perforations 228 may be formed through the sealing adhesive 230 and the peripheral portion 214 of the first film layer 204. The first plurality of perforations 226 and the second plurality of perforations 228 may be formed by punching or another method of forming perforations. In some embodiments, the boundary 218 may also be without the sealing adhesive 230.

[0091] Referring to FIG. 5, therapy system 100 is shown at tissue site 502. Tissue site 502 can extend through epidermis 504, dermis 506, and subcutaneous tissue 508, or can alternatively include them. Tissue site 502 can be a sub - surface tissue site represented in FIG. 5 that extends below the surface of epidermis 504. Further, tissue site 502 can be a surface tissue site (not shown) that mainly exists on the surface of epidermis 504, such as an incision. Therapy system 100 can provide therapy to, for example, epidermis 504, dermis 506, and subcutaneous tissue 508, regardless of the placement of therapy system 100 or the type of tissue site. Therapy system 100 can also be used at other tissue sites, although not limited to them.

[0092] Therapy system 100 can include dressing material 110, container 115, and a negative pressure source 105 that can include therapy unit 145. Further, therapy system 100 can include filling material 510 as an optional component of therapy system 100, which can be omitted for different types of tissue sites or different types of therapies using negative pressure (such as epithelialization). When equipped, filling material 510 can be adapted to be placed in proximity to tissue site 502, or adjacent to the tissue site, for example, by cutting filling material 510 in any suitable manner, or otherwise shaping it, so as to fit tissue site 502 and fill the space between tissue site 502 and dressing material 110. Similar to manifold 202 of tissue interface 120, filling material 510 can be constructed of the manifold material described herein and can be adapted to be placed in fluid communication with tissue site 502 so as to distribute negative pressure to tissue site 502. In some embodiments, filling material 510 can be placed in direct contact with tissue site 502 and between tissue site 502 and dressing material 110. When filling material 510 is omitted, the tissue interface 120 of dressing material 110 can be placed in direct contact with tissue site 502. Dressing material 110 can be adapted to provide or distribute negative pressure from negative pressure source 105 of therapy unit 145 to tissue site 502, either directly or, when equipped, through filling material 510.

[0093] Referring to FIGS. 5A and 5B, a detailed view of a portion of the therapy system 100 of FIG. 5 at reference numeral 5A is shown. FIG. 5A shows the dressing 110 before a force is applied to the dressing 110 to push the adhesive 236 through a second plurality of perforations 228 in the first film layer 204. FIG. 5B shows the dressing 110 after the force 520 has been applied to the dressing 110. As described above, the adhesive 236 may be in fluid communication with or otherwise exposed to the attachment surface through the second plurality of perforations 228 at least within the peripheral portion 214 of the first film layer 204 in some embodiments. In some embodiments, the attachment surface may be the epidermis 504 of the tissue site 502. The adhesive 236 may also be in fluid communication with the edge 222 through the second plurality of perforations 228 exposed at the edge 222. When the dressing 110 is in the desired position as shown in FIG. 5A, the adhesive 236 may be pressed through the second plurality of perforations 228 to bond the dressing 110 to the epidermis 504. The second plurality of perforations 228 at the edge 222 may allow the adhesive 236 to flow around the edge 222 and enhance the adhesion of the edge 222 to the attachment surface.

[0094] Referring to FIGS. 6A and 6B, another embodiment of the dressing material 110 is shown. The cover 125, the tissue interface 120, the dressing material interface 258, and the fluid conduit 256 may be substantially as described above with reference to FIG. 2. The carrier 242 may be of a different shape in some embodiments than that shown in FIG. 2. For example, the carrier 242 may be substantially rectangular and may include a central opening 602. The carrier 242 may have a first portion 604, a second portion 606 on the opposite side of the first portion 604, a third portion 608 that joins the first portion 604 and the second portion 606, and a fourth portion 610 on the opposite side of the third portion 608. The dressing material interface 258 may be coupled to the opening 262 of the cover 125 through the central opening 602 of the carrier 242. In other embodiments, the carrier 242 may be of another shape or size that can provide structure to the dressing material 110 before and after the release liner 240 is removed from the dressing material 110.

[0095] The systems, devices, and methods described herein may provide significant advantages compared to conventional dressing materials. The dressing material 110 may be thin and highly conformable since the tissue interface 120 may include the manifold 202 and the first film layer 204 having a sealing adhesive 230 pattern-coated on the second surface 212 of the first film layer 204. Due to the thin structure, the dressing material 110 may also be breathable. The dressing material 110 may also be easier to lift from the tissue site 502 due to the thin edge thickness of the dressing material 110.

[0096] Although several exemplary embodiments have been shown, those skilled in the art will recognize that various changes and modifications can be made to the systems, devices, and methods described herein within the scope of the appended claims. Further, the description of various alternatives using terms such as "or" does not require mutual exclusivity unless clearly required by the context, and the indefinite article "a" or "an" does not limit the object to a single instance unless clearly required by the context. Components can also be combined or excluded in various configurations for the purpose of sale, manufacture, assembly, or use. For example, in some configurations, the dressing material 110, the container 115, or both can be excluded or separated from the components for manufacture or sale.

[0097] The appended claims recite novel and inventive aspects of the above subject matter, but the claims may also encompass additional subject matter not specifically described in detail. For example, a particular feature, element, or aspect may be omitted from the claims if it is not necessary to distinguish novel and inventive features from those already known to those skilled in the art. Features, elements, and aspects described in the context of some embodiments can also be omitted, combined, or replaced by alternative features that serve the same, equivalent, or similar purpose without departing from the scope of the invention defined by the appended claims.

Claims

1. A dressing material configured to be positioned adjacent to a tissue site, A first film layer comprising: a treatment area and a sealing area surrounding the treatment area; a first plurality of perforations formed through the treatment area; a second plurality of perforations formed through the sealing area and larger than the first plurality of perforations; and a sealing adhesive covering the sealing area on a first surface of the first film layer configured to face the tissue area. A manifold disposed adjacent to the second surface of the first film layer, wherein the second surface is opposite to the first surface, and the manifold A dressing material comprising: a cover layer including a second film layer and a cover adhesive, wherein the cover layer is placed on the manifold and bonded to the second surface of the first film layer around the manifold, and the cover adhesive is placed adjacent to the second plurality of perforations.

2. The dressing material according to claim 1, wherein the first film layer comprises a polyurethane film having a thickness of about 20 microns to about 35 microns.

3. The dressing material according to claim 1, wherein the sealing adhesive comprises a silicone adhesive having a coating weight of about 100 grams / square meter to about 250 grams / square meter.

4. The dressing material according to claim 1, wherein the manifold includes an open-cell foam having a thickness of about 5 mm to about 10 mm.

5. The dressing material according to claim 1, wherein the second film layer comprises a polyurethane film having a thickness of about 20 microns to about 35 microns.

6. The dressing material according to claim 1, wherein the cover adhesive comprises an acrylic adhesive having a coating weight of approximately 25 grams / square meter to approximately 65 grams / square meter.

7. The dressing material according to claim 1, wherein the cover adhesive is configured to extend from the second surface of the first film layer to the first surface of the first film layer through the second plurality of perforations.

8. The dressing material according to claim 1, wherein the treatment area is configured to contact the tissue site, and the sealing area is configured to contact the epidermis surrounding the tissue site.

9. The dressing material according to claim 1, wherein the treatment area is configured such that the first surface of the first film layer in the treatment area is in direct contact with the tissue site, and is free of adhesive.

10. The dressing material according to claim 1, wherein the first plurality of perforations include slits arranged in a certain pattern.

11. The dressing material according to claim 1, wherein the second plurality of perforations include circular openings arranged in a certain pattern.

12. The dressing material according to claim 1, wherein each of the first plurality of perforations has a first open area, and each of the second plurality of perforations has a second open area that is larger than the first open area.

13. The dressing material according to claim 1, wherein the first plurality of perforations have a different shape from the second plurality of perforations.

14. The dressing material according to claim 1, wherein the second plurality of perforations are larger than the first plurality of perforations in at least one dimension.

15. The dressing material according to claim 1, wherein the first plurality of perforations are configured to increase in size when the tissue site is exposed to pressure, the second plurality of perforations do not change in size when exposed to pressure, and the second plurality of perforations are larger in size than the first plurality of perforations when the tissue site is exposed to pressure and when the tissue site is not exposed to pressure.

16. The dressing material according to claim 1, further comprising a carrier layer removably bonded to the surface of the cover layer opposite to the cover adhesive.

17. The dressing material according to claim 16, wherein the carrier layer comprises coated paper or polymer film.

18. A system for treating tissue sites using negative pressure therapy, The dressing material according to claim 1, A system comprising: a negative pressure source configured to be fluidly coupled to the tissue site through the cover layer.

19. A system for treating tissue sites using negative pressure therapy, A dressing material configured to be positioned adjacent to the aforementioned tissue site, Career level, A first film layer comprising: a treatment area and a sealing area surrounding the treatment area; a plurality of slits formed through the treatment area; a plurality of holes formed through the sealing area and having an open area larger than the plurality of slits; and a sealing adhesive covering the sealing area on the surface of the first film layer configured to face the tissue area. Manifold and, A dressing material comprising: a second film layer including an opening, wherein the surface of the second film layer configured to face the tissue area is coated with a pressure-sensitive adhesive; The carrier layer, the first film layer, the manifold, and the second film layer are assembled in such a way that the first film layer and the second film layer are stacked with the manifold enclosing it, the manifold is aligned with the treatment area, the pressure-sensitive adhesive and the sealing adhesive are configured to face the tissue area, at least a portion of the pressure-sensitive adhesive is exposed through the plurality of holes, and the carrier layer is laminated on the second film layer on the side of the second film layer opposite the pressure-sensitive adhesive. A system in which a negative pressure source is configured to be fluidly coupled to the tissue site through the opening, the manifold, and the plurality of slits.

20. The system according to claim 19, wherein the sealing adhesive is not placed on the treatment area.

21. The system according to claim 19, wherein the carrier layer comprises coated paper or polymer film, and the carrier layer is configured to be removed from the second film layer after the dressing material has been placed adjacent to the tissue site.

Images