WO2021140468A1

WO2021140468A1 - Systems and apparatuses for wound cleansing and tissue deformation

Info

Publication number: WO2021140468A1
Application number: PCT/IB2021/050101
Authority: WO
Inventors: Diwi L. Allen; Prathamesh Madhav KHARKAR; Marisa Schmidt
Original assignee: KCI Licensing Inc
Current assignee: KCI Licensing Inc
Priority date: 2020-01-09
Filing date: 2021-01-07
Publication date: 2021-07-15
Anticipated expiration: 2022-07-09

Abstract

Dressings, systems, and methods for treating a tissue site with negative pressure are described. The dressing includes a foam having a foam thickness from a first side of the foam to a second side of the foam, and a plurality of holes extending through the foam from the first side to the second side. The dressing also includes a film having a film thickness and a plurality of perforations extending through the film. A plurality of welds couple the film to the first side of the foam, each of the plurality of welds being separated from the plurality of holes. Other dressings include a contact layer having a plurality of perforations extending through the contact layer, and a plurality of tissue disruption members coupled to the contact layer. The tissue disruption members are spaced apart from each other.

Description

SYSTEMS AND APPARATUSES FOR WOUND CLEANSING AND TISSUE DEFORMATION

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Application No. 62/958,830, filed on January 9, 2020, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0002] The invention set forth in the appended claims relates generally to tissue treatment systems and more particularly, but without limitation, to systems, dressings, and fillers for negative-pressure tissue treatment, and methods of using systems, dressings, and fillers for negative-pressure tissue treatment.

BACKGROUND

[0003] Clinical studies and practice have shown that reducing pressure in proximity to a tissue site can augment and accelerate growth of new tissue at the tissue site. The applications of this phenomenon are numerous, but it has proven particularly advantageous for treating wounds. Regardless of the etiology of a wound, whether trauma, surgery, or another cause, proper care of the wound is important to the outcome. Treatment of wounds or other tissue with reduced pressure may be commonly referred to as "negative-pressure therapy," but is also known by other names, including "negative-pressure wound therapy," "reduced-pressure therapy," "vacuum therapy," "vacuum-assisted closure," and "topical negative- pressure," for example. Negative-pressure therapy may provide a number of benefits, including migration of epithelial and subcutaneous tissues, improved blood flow, and micro-deformation of tissue at a wound site. Together, these benefits can increase development of granulation tissue and reduce healing times.

[0004] There is also widespread acceptance that cleansing a tissue site can be highly beneficial for new tissue growth. For example, a wound can be washed out with a stream of liquid solution, or a cavity can be washed out using a liquid solution for therapeutic purposes. These practices are commonly referred to as "irrigation" and "lavage" respectively. "Instillation" is another practice that generally refers to a process of slowly introducing fluid to a tissue site and leaving the fluid for a prescribed period of time before removing the fluid. For example, instillation of topical treatment solutions over a wound bed can be combined with negative-pressure therapy to further promote wound healing by loosening soluble contaminants in a wound bed and removing infectious material. As a result, soluble bacterial burden can be decreased, contaminants removed, and the wound cleansed. [0005] While the clinical benefits of negative-pressure therapy and instillation therapy are widely known, improvements to therapy systems, components, and processes may benefit healthcare providers and patients.

BRIEF SUMMARY

[0006] New and useful systems, apparatuses, and methods for treating tissue in a negative-pressure therapy environment are set forth in the appended claims. Illustrative embodiments are also provided to enable a person skilled in the art to make and use the claimed subject matter.

[0007] For example, a dressing for treating a tissue site is described. The dressing can include a foam having a foam thickness from a first side of the foam to a second side of the foam, and a plurality of holes extending through the foam from the first side to the second side. The dressing can also include a film having a film thickness and a plurality of perforations extending through the film. A plurality of welds can couple the film to the first side of the foam, each of the plurality of welds being separated from the plurality of holes.

[0008] In some embodiments, the foam can have a plurality of raised portions surrounding the plurality of holes and a plurality of depending portions coincident with the plurality of welds. In some embodiments, the film is a first film, and the plurality of welds are a first plurality of welds. The dressing can further include a second film having a second film thickness and a second plurality of perforations extending through the second film. A second plurality of welds can couple the film to the second side of the foam, each of the second plurality of welds being separated from the plurality of holes.

[0009] More generally, in some embodiments, a dressing for treating a tissue site is described. The dressing can include a contact layer having a plurality of perforations extending through the contact layer, and a plurality of tissue disruption members coupled to the contact layer. The tissue disruption members can be spaced apart from each other.

[0010] Other example embodiments may relate to a method for treating a tissue site with negative- pressure. A dressing for treating the tissue site can be provided. The dressing may have a foam having a foam thickness from a first side of the foam to a second side of the foam. The foam can also having a plurality of holes extending through the foam from the first side to the second side. The dressing may also have a film having a film thickness and a plurality of perforations extending through the film and a plurality of welds coupling the film to the first side of the foam. Each of the plurality of welds can be separated from the plurality of holes. The dressing can be positioned adjacent to the tissue site, and a negative-pressure source can be fluidly coupled to the dressing. Negative pressure can be applied to the dressing with the negative-pressure source, and a portion of the film and the tissue site can be drawn into the plurality of holes.

[0011] In still another example embodiment, a method for treating a tissue site with negative- pressure is described. A dressing for treating the tissue site can be provided. The dressing can include a contact layer having a plurality of perforations extending through the contact layer. The dressing can also include a plurality of tissue disruption members coupled to the contact layer. The tissue disruption members can be spaced apart from each other to create free areas between the tissue disruption members. The dressing can be positioned adjacent to the tissue site and fluidly coupled to a negative-pressure source. Negative pressure can be applied to the dressing with the negative-pressure source, and a portion of the contact layer and the tissue site can be drawn into the free areas.

[0012] 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

[0013] Figure 1 is a functional block diagram of an example embodiment of a therapy system that can provide negative-pressure treatment in accordance with this specification.

[0014] Figure 2 is an exploded view of a dressing that may be associated with an example embodiment of the therapy system of Figure 1.

[0015] Figure 3 is a bottom perspective view of a tissue interface of the dressing of Figure 2.

[0016] Figure 4 is a cross-sectional view of the tissue interface of Figure 3 taken along line 4 — 4.

[0017] Figure 5 is a bottom view of the tissue interface of Figure 3 illustrating additional details that may be associated with some embodiments.

[0018] Figure 6 is a sectional view of the tissue interface of Figure 3 illustrating additional details that may be associated with the placement of the tissue interface at a tissue site.

[0019] Figure 7 is a sectional view of the tissue interface of Figure 3 illustrating details associated with the tissue interface while under negative pressure.

[0020] Figure 8 is a detail view of a portion of the tissue interface of Figure 7.

[0021] Figure 9 is an exploded view of another dressing that may be associated with an embodiment of the therapy system of Figure 1.

[0022] Figure 10 is a sectional view of the tissue interface of Figure 9 taken along line 10 — 10.

[0023] Figure 11 is a bottom perspective view of another tissue interface that may be associated with an example embodiment of the therapy system of Figure 1.

[0024] Figure 12 is a sectional view of the tissue interface of Figure 11 taken along line 12 — 12. [0025] Figure 13 is a perspective view of a bottom of another tissue interface that may be associated with an example embodiment of the therapy system of Figure 1.

[0026] Figure 14 is a sectional view of the tissue interface of Figure 13 taken along line 14 — 14.

[0027] Figure 15 is a sectional view of the tissue interface of Figure 13 illustrating additional details that may be associated with the placement of the tissue interface at a tissue site.

[0028] Figure 16 is a sectional view of the tissue interface of Figure 13 illustrating additional details that may be associated with the application of negative pressure to the tissue interface.

[0029] Figure 17 is a perspective view of a bottom of another tissue interface that may be associated with an example embodiment of the therapy system of Figure 1.

[0030] Figure 18 is a sectional view of the tissue interface of Figure 11 taken along line 18 — 18.

[0031] Figure 19 is a perspective view of a bottom of another tissue interface that may be associated with an example embodiment of the therapy system of Figure 1.

[0032] Figure 20 is a perspective view of a bottom of another tissue interface that may be associated with an example embodiment of the therapy system of Figure 1.

DESCRIPTION OF EXAMPLE EMBODIMENTS

[0033] The following description of example embodiments provides information that enables a person skilled in the art to make and use the subject matter set forth in the appended claims, but may omit certain details already well-known in the art. The following detailed description is, therefore, to be taken as illustrative and not limiting.

[0034] 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.

[0035] The term “tissue site” in this context broadly refers to a wound, defect, or other treatment target located on or within tissue, including but not limited to, a surface wound, bone tissue, adipose tissue, muscle tissue, neural tissue, dermal tissue, vascular tissue, connective tissue, cartilage, tendons, or ligaments. The term “tissue site” may also refer to areas of any tissue that are not necessarily wounded or defective, but are instead areas in which it may be desirable to add or promote the growth of additional tissue. For example, negative pressure may be applied to a tissue site to grow additional tissue that may be harvested and transplanted. A surface wound, as used herein, is a wound on the surface of a body that is exposed to the outer surface of the body, such an injury or damage to the epidermis, dermis, and/or subcutaneous layers. Surface wounds may include ulcers or closed incisions, for example. A surface wound, as used herein, does not include wounds within an intra-abdominal cavity. A wound may include chronic, acute, traumatic, subacute, and dehisced wounds, partial-thickness bums, ulcers (such as diabetic, pressure, or venous insufficiency ulcers), flaps, and grafts, for example.

[0036] Figure 1 is a simplified functional block diagram of an example embodiment of a therapy system 100 that can provide negative-pressure therapy with instillation of topical treatment solutions to a tissue site in accordance with this specification. The therapy system 100 may include a source or supply of negative pressure, such as a negative-pressure source 102, a dressing 104, a fluid container, such as a container 106, and a regulator or controller, such as a controller 108, for example. Additionally, the therapy system 100 may include sensors to measure operating parameters and provide feedback signals to the controller 108 indicative of the operating parameters. As illustrated in Figure 1, for example, the therapy system 100 may include a pressure sensor 110, an electric sensor 112, or both, coupled to the controller 108. As illustrated in the example of Figure 1, the dressing 104 may comprise or consist essentially of a tissue interface 114, a cover 116, or both in some embodiments.

[0037] The therapy system 100 may also include a source of instillation solution. For example, a solution source 118 may be fluidly coupled to the dressing 104, as illustrated in the example embodiment of Figure 1. The solution source 118 may be fluidly coupled to a positive-pressure source such as the positive-pressure source 120, a negative-pressure source such as the negative-pressure source 102, or both in some embodiments. A regulator, such as an instillation regulator 122, may also be fluidly coupled to the solution source 118 and the dressing 104 to ensure proper dosage of instillation solution (e.g. saline) to a tissue site. For example, the instillation regulator 122 may comprise a piston that can be pneumatically actuated by the negative-pressure source 102 to draw instillation solution from the solution source during a negative-pressure interval and to instill the solution to a dressing during a venting interval. Additionally or alternatively, the controller 108 may be coupled to the negative-pressure source 102, the positive- pressure source 120, or both, to control dosage of instillation solution to a tissue site. In some embodiments, the instillation regulator 122 may also be fluidly coupled to the negative-pressure source 102 through the dressing 104, as illustrated in the example of Figure 1.

[0038] Some components of the therapy system 100 may be housed within or used in conjunction with other components, such as sensors, processing units, alarm indicators, memory, databases, software, display devices, or user interfaces that further facilitate therapy. For example, in some embodiments, the negative-pressure source 102 may be combined with the solution source 118, the controller 108, and other components into a therapy unit.

[0039] In general, components of the therapy system 100 may be coupled directly or indirectly. For example, the negative-pressure source 102 may be directly coupled to the container 106 and may be indirectly coupled to the dressing 104 through the container 106. Coupling may include fluid, mechanical, thermal, electrical, or chemical coupling (such as a chemical bond), or some combination of coupling in some contexts. For example, the negative-pressure source 102 may be electrically coupled to the controller 108 and may be fluidly coupled to one or more distribution components to provide a fluid path to a tissue site. In some embodiments, components may also be coupled by virtue of physical proximity, being integral to a single structure, or being formed from the same piece of material. For example, the tissue interface 114 and the cover 116 may be discrete layers disposed adjacent to each other and may be joined together in some embodiments.

[0040] A distribution component is preferably detachable, and may be disposable, reusable, or recyclable. The dressing 104 and the container 106 are illustrative of distribution components. A fluid conductor is another illustrative example of a distribution component. A "fluid conductor," in this context, broadly includes a tube, pipe, hose, conduit, or other structure with one or more lumina or open pathways adapted to convey a fluid between two ends. Typically, a tube is an elongated, cylindrical structure with some flexibility, but the geometry and rigidity may vary. Moreover, some fluid conductors may be molded into or otherwise integrally combined with other components. Distribution components may also include or comprise interfaces or fluid ports to facilitate coupling and de-coupling other components. In some embodiments, for example, a dressing interface may facilitate coupling a fluid conductor to the dressing 104.

[0041] A negative-pressure supply, such as the negative-pressure source 102, may be a reservoir of air at a negative pressure, or may be a manual or electrically-powered device, such as a vacuum pump, a suction pump, a wall suction port available at many healthcare facilities, or a micro-pump, for example. “Negative pressure” generally refers to a pressure less than a local ambient pressure, such as the ambient pressure in a local environment external to a sealed therapeutic environment. In many cases, the local ambient pressure may also be the atmospheric pressure at which a tissue site is located. Alternatively, the pressure may be less than a hydrostatic pressure associated with tissue at the tissue site. Unless otherwise indicated, values of pressure stated herein are gauge pressures. References to increases in negative pressure typically refer to a decrease in absolute pressure, while decreases in negative pressure typically refer to an increase in absolute pressure. While the amount and nature of negative pressure applied to a tissue site may vary according to therapeutic requirements, the pressure is generally a low vacuum, also commonly referred to as a rough vacuum, between -5 mm Hg (-667 Pa) and -500 mm Hg (-66.7 kPa). Common therapeutic ranges are between -50 mm Hg (-6.7 kPa) and -300 mm Hg (-39.9 kPa).

[0042] The container 106 is representative of a container, canister, pouch, or other storage component, which can be used to manage exudates and other fluids withdrawn from a tissue site. In many environments, a rigid container may be preferred or required for collecting, storing, and disposing of fluids. In other environments, fluids may be properly disposed of without rigid container storage, and a re-usable container could reduce waste and costs associated with negative-pressure therapy. [0043] A controller, such as the controller 108, may be a microprocessor or computer programmed to operate one or more components of the therapy system 100, such as the negative-pressure source 102. In some embodiments, for example, the controller 108 may be a microcontroller, which generally comprises an integrated circuit containing a processor core and a memory programmed to directly or indirectly control one or more operating parameters of the therapy system 100. Operating parameters may include the power applied to the negative-pressure source 102, the pressure generated by the negative-pressure source 102, or the pressure distributed to the tissue interface 114, for example. The controller 108 is also preferably configured to receive one or more input signals, such as a feedback signal, and programmed to modify one or more operating parameters based on the input signals.

[0044] Sensors, such as the pressure sensor 110 or the electric sensor 112, are generally known in the art as any apparatus operable to detect or measure a physical phenomenon or property, and generally provide a signal indicative of the phenomenon or property that is detected or measured. For example, the pressure sensor 110 and the electric sensor 112 may be configured to measure one or more operating parameters of the therapy system 100. In some embodiments, the pressure sensor 110 may be a transducer configured to measure pressure in a pneumatic pathway and convert the measurement to a signal indicative of the pressure measured. In some embodiments, the pressure sensor 110 may be a piezoresistive strain gauge. The electric sensor 112 may optionally measure operating parameters of the negative-pressure source 102, such as the voltage or current, in some embodiments. Preferably, the signals from the pressure sensor 110 and the electric sensor 112 are suitable as an input signal to the controller 108, but some signal conditioning may be appropriate. For example, the signal may need to be filtered or amplified before it can be processed by the controller 108. Typically, the signal is an electrical signal, but may be represented in other forms, such as an optical signal.

[0045] The tissue interface 114 can be generally adapted to partially or fully contact a tissue site. The tissue interface 114 may take many forms, and may have many sizes, shapes, or thicknesses depending on a variety of factors, such as the type of treatment being implemented or the nature and size of a tissue site. For example, the size and shape of the tissue interface 114 may be adapted to the contours of deep and irregular shaped tissue sites.

[0046] In some embodiments, the cover 116 may provide a bacterial barrier and protection from physical trauma. The cover 116 may also be constructed from a material that can reduce evaporative losses and provide a fluid seal between two components or two environments, such as between a therapeutic environment and a local external environment. The cover 116 may be, for example, an elastomeric film or membrane that can provide a seal adequate to maintain a negative pressure at a tissue site for a given negative-pressure source. The cover 116 may have a high moisture-vapor transmission rate (MVTR) in some applications. For example, the MVTR may be at least about 300 g/m² per twenty-four hours in some embodiments. In some example embodiments, the cover 116 may be a polymer drape, such as a polyurethane film, that is permeable to water vapor but impermeable to liquid. Such drapes typically have a thickness in the range of about 25 microns to about 50 microns. For permeable materials, the permeability generally should be low enough that a desired negative pressure may be maintained.

[0047] The cover 116 may comprise, for example, one or more of the following materials: hydrophilic polyurethane; cellulosics; hydrophilic polyamides; polyvinyl alcohol; polyvinyl pyrrolidone; hydrophilic acrylics; hydrophilic silicone elastomers; an INSPIRE 2301 material from Coveris Advanced Coatings of Wrexham, United Kingdom having, for example, an MVTR (inverted cup technique) of about 14400 g/m²/24 hours and a thickness of about 30 microns; a thin, uncoated polymer drape; natural rubbers; polyisoprene; styrene butadiene rubber; chloroprene rubber; polybutadiene; nitrile rubber; butyl rubber; ethylene propylene rubber; ethylene propylene diene monomer; chlorosulfonated polyethylene; polysulfide rubber; polyurethane (PU); EVA film; co-polyester; silicones; a silicone drape; a 3M Tegaderm® drape; a polyurethane (PU) drape such as one available from Avery Dennison Corporation of Glendale, California; polyether block polyamide copolymer (PEBAX), for example, from Arkema, France; INSPIRE 2327; or other appropriate material.

[0048] An attachment device may be used to attach the cover 116 to an attachment surface, such as undamaged epidermis, a gasket, or another cover. The attachment device may take many forms. For example, an attachment device may be a medically-acceptable, pressure-sensitive adhesive configured to bond the cover 116 to epidermis around a tissue site. In some embodiments, for example, some or all of the cover 116 may be coated with an adhesive, such as an acrylic adhesive, which may have a coating weight between about 25 grams per square meter (g.s.m.) to about 65 g.s.m. Thicker adhesives, or combinations of adhesives, may be applied in some embodiments to improve the seal and reduce leaks. Other example embodiments of an attachment device may include a double-sided tape, paste, hydrocolloid, hydrogel, silicone gel, or organogel.

[0049] The solution source 118 may also be representative of a container, canister, pouch, bag, or other storage component, which can provide a solution for instillation therapy. Compositions of solutions may vary according to a prescribed therapy, but examples of solutions that may be suitable for some prescriptions include hypochlorite-based solutions, silver nitrate (0.5%), sulfur-based solutions, biguanides, cationic solutions, and isotonic solutions.

[0050] The fluid mechanics of using a negative-pressure source to reduce pressure in another component or location, such as within a sealed therapeutic environment, can be mathematically complex. However, the basic principles of fluid mechanics applicable to negative-pressure therapy and instillation are generally well-known to those skilled in the art, and the process of reducing pressure may be described illustratively herein as “delivering,” “distributing,” or “generating” negative pressure, for example. [0051] In general, exudates and other fluids flow toward lower pressure along a fluid path. Thus, the term “downstream” typically implies a position in a fluid path relatively closer to a source of negative pressure or further away from a source of positive pressure. Conversely, the term “upstream” implies a position relatively further away from a source of negative pressure or closer to a source of positive pressure. Similarly, it may be convenient to describe certain features in terms of fluid “inlet” or “outlet” in such a frame of reference. This orientation is generally presumed for purposes of describing various features and components herein. However, the fluid path may also be reversed in some applications (such as by substituting a positive-pressure source for a negative-pressure source) and this descriptive convention should not be construed as a limiting convention.

[0052] Some tissue sites can develop thick exudate, become colonized with microbes, and/or develop large areas of necrotic tissue or slough. Tissue sites having thick exudate, slough, or that have been colonized by microbes can cease to respond to treatment. For example, during treatment of a tissue site, some tissue sites may not heal according to the normal medical protocol and may develop areas of necrotic tissue. Necrotic tissue may be dead tissue resulting from infection, toxins, or trauma that caused the tissue to die faster than the dead tissue can be removed by the normal body processes that regulate the removal of dead tissue. Sometimes, necrotic tissue may be in the form of slough, which may include a viscous liquid mass of tissue. Generally, slough is produced by bacterial and fungal infections that stimulate an inflammatory response in the tissue. Slough may be a creamy yellow color and may also be referred to as pus. Necrotic tissue may also include eschar. Eschar may be a portion of necrotic tissue that has become dehydrated and hardened. Eschar may be the result of a bum injury, gangrene, ulcers, fungal infections, spider bites, or anthrax. Eschar may be difficult to remove without the use of surgical cutting instruments.

[0053] In addition to necrotic tissue, the tissue site may include biofilms, lacerated tissue, devitalized tissue, contaminated tissue, damaged tissue, infected tissue, exudate, highly viscous exudate, fibrinous slough and/or other material that can generally be referred to as debris. The debris may inhibit the efficacy of tissue treatment and slow the healing of the tissue site. If the debris is in the tissue site, the tissue site may be treated with different processes to disrupt the debris. Examples of disruption can include softening of the debris, separation of the debris from desired tissue, such as the subcutaneous tissue, preparation of the debris for removal from the tissue site, and removal of the debris from the tissue site.

[0054] To aid the healing process, the debris can require debridement performed in an operating room. In some cases, tissue sites requiring debridement may not be life-threatening, and debridement may be considered low priority. Low-priority cases can experience delays prior to treatment as other, more life- threatening, cases may be given priority for an operating room. As a result, low priority cases may need temporization. Temporization can include stasis of a tissue site that limits deterioration of the tissue site prior to other treatments, such as debridement, negative-pressure therapy or instillation. [0055] When debriding, clinicians may find it difficult to define separation between healthy, vital tissue and necrotic tissue. As a result, normal debridement techniques may remove too much healthy tissue or not enough necrotic tissue. If non-viable tissue demarcation does not extend deeper than the deep dermal layer, or if the tissue site is covered by the debris, such as slough or fibrin, gentle methods to remove the debris should be considered to avoid excess damage to the tissue site.

[0056] In some debridement processes, a mechanical process is used to remove the debris. Mechanical processes may include using scalpels or other cutting tools having a sharp edge to cut away the debris from the tissue site. Other mechanical processes may use devices that can provide a stream of particles to impact the debris to remove the debris in an abrasion process, or jets of high-pressure fluid to impact the debris to remove the debris using water-jet cutting or lavage. Typically, mechanical processes of debriding a tissue site may be painful and may require the application of local anesthetics. Mechanical processes must often be performed in an operating suite and often require removal of tissue until bleeding is evident. Mechanical processes also risk over removal of healthy tissue that can cause further damage to the tissue site and delay the healing process.

[0057] Debridement may also be performed with an autolytic process. For example, an autolytic process may involve using enzymes and moisture produced by a tissue site to soften and liquefy the necrotic tissue and debris. Typically, a dressing may be placed over a tissue site having debris so that fluid produced by the tissue site may remain in place, hydrating the debris. Autolytic processes can be pain-free, but autolytic processes are a slow and can take many days. Because autolytic processes are slow, autolytic processes may also involve many dressing changes. Some autolytic processes may be paired with negative- pressure therapy so that, as debris hydrates, negative pressure supplied to a tissue site may draw off the debris. In some cases, a manifold positioned at a tissue site to distribute negative-pressure across the tissue site may become blocked or clogged with debris broken down by an autolytic process. If a manifold becomes clogged, negative-pressure therapy may not be able to remove debris, which can slow or stop the autolytic process.

[0058] Debridement may also be performed by adding enzymes or other agents to the tissue site that digest tissue. Often, strict control of the placement of the enzymes and the length of time the enzymes are in contact with a tissue site must be maintained. If enzymes are left on a tissue site for longer than needed, the enzymes may remove too much healthy tissue, contaminate the tissue site, or be carried to other areas of a patient. Once carried to other areas of a patient, the enzymes may break down undamaged tissue and cause other complications.

[0059] The therapy system 100 can provide tissue site preparation for devitalized tissue/slough removal while inducing robust granulation tissue formation and re-epithelization. Specifically, the tissue interface 114 can include a felted or non-felted foam welded to a polyurethane film that may or may not have holes. The tissue interface 114 can create tissue deformation that effectively removes unwanted tissue while stimulating granulation tissue formation that aids in the removal of devitalized tissue and stimulates granulation by using geometries, topographies, or macrostructural designs.

[0060] Figure 2 is an assembly view of an example of the dressing 104 of Figure 1, illustrating additional details that may be associated with some embodiments. In the example of Figure 2, the tissue interface 114 comprises a first layer 202 and a second layer 204. In some embodiments, the first layer 202 may be adjacent to the second layer 204. The first layer 202 may also be coupled to the second layer 204.

[0061] The first layer 202 may have a first surface 206 and a second surface 208. In some embodiments, the first layer 202 may comprise or consist essentially of a means for controlling or managing fluid flow. In some embodiments, the first layer 202 may comprise or consist essentially of an elastomeric material that is impermeable to liquid. For example, the first layer 202 may comprise or consist essentially of a polymer film. The first layer 202 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 first layer 202 may have a substantially flat surface, with height variations limited to 0.2 millimeters over a centimeter.

[0062] In some embodiments, the first layer 202 may comprise or consist essentially of a hydrophobic material. The hydrophobicity may vary but may have a contact angle with water of at least ninety degrees. In some embodiments the hydrophobic material may have a contact angle with water of no more than 150 degrees. For example, the contact angle 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 FTAl25, FTA2OO, FTA2OOO, 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 first layer 202 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. [0063] The first layer 202 may also be suitable for bonding to other layers, including the second layer 204. For example, the first layer 202 may be adapted for welding to polyurethane foams using heat, radio frequency (RF) welding, or other methods to generate heat such as ultrasonic welding. RF welding may be particularly suitable for more polar materials, such as polyurethane, polyamides, polyesters and acrylates. Sacrificial polar interfaces may be used to facilitate RF welding of less polar film materials, such as polyethylene. The first layer 202 may include hot melt films.

[0064] The area density of the first layer 202 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.

[0065] In some embodiments, for example, the first layer 202 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, polyethylene, polyvinyl alcohols, polyvinyl chloride, polypropylene, polymethylpentene, polycarbonate, styreneics, silicones, fluoropolymers, cellophase, cellulose acetate, and other acetates. A thickness between 25 microns and 200 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, co-polyesters, 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 (EMA) film may also have suitable hydrophobic and welding properties for some configurations. In some embodiments, the first layer 202 may be formed of a transparent polymer to aid in cutting. In some embodiments, the first layer 202 can be printed with various information, such as product identification, instructions for placement, cutting or sizing, or numbers. In some embodiments, the first layer 202 can be impregnated with antimicrobial compounds, such as about 1% to about 5% chlorhexidine, about 0.2% to about 5% silver, about 0.2% to about 5% gold, about 0.2% to about 5% copper, and about 0.2% to about 5% palladium.

[0066] As illustrated in the example of Figure 2, the first layer 202 may have one or more fluid restrictions 210, which can be distributed uniformly or randomly across the first layer 202. The fluid restrictions 210 may be bi-directional and pressure responsive. For example, each of the fluid restrictions 210 generally may comprise or consist essentially of an elastic passage that is normally unstrained to substantially reduce liquid flow and can expand or open in response to a pressure gradient. [0067] Some embodiments of the fluid restrictions 210 may comprise or consist essentially of one or more slits, slots or combinations of slits and slots. In some examples, the fluid restrictions 210 may comprise or consist of linear slots having a length less than 5 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 0.8 millimeters may be particularly suitable for many applications, and a tolerance of about 0.1 millimeters may also be acceptable. Such dimensions and tolerances may be achieved with a laser cutter, for example. In some embodiments, the fluid restrictions 210 may be formed by ultrasonics or other heat means. 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.

[0068] In some embodiments, the fluid restrictions 210 may comprise or consist essentially of perforations in the first layer 202. Perforations may be formed by removing material from the first layer 202. For example, perforations may be formed by cutting through the material, 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 210 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 material may be a suitable valve for some applications. Fenestrations may also be formed by removing material, but the amount of material removed and the resulting dimensions of the fenestrations may be an order of magnitude less than perforations, and may not deform the edges. In some embodiments, the fluid restrictions 210 extend through the first layer 202.

[0069] The first layer 202 may also comprise a plurality of through-holes 212. The through-holes 212 may be openings, perforations, or other voids formed in the first layer 202. The through-holes 212 may permit fluid communication across the first layer 202 through the through-holes 212. In some embodiments, the through-holes 212 may comprise or consist essentially of areas of the first layer 202 where the material of the first layer 202 has been removed. The through-holes 212 may have a circular, elliptical, or polygonal shape. In some embodiments, the through-holes 212 may have an average effective diameter between about 0.5 mm and about 5 mm. An effective diameter of a non-circular area may be a diameter of a circular area having the same surface area as the non-circular area.

[0070] The second layer 204 may have a first surface 214, a second surface 216, and a plurality of through-holes 218 extending through the second layer 204 from the first surface 214 to the second surface 216. A debridement tool, such as the second layer 204 may have a thickness 220. In some embodiments, the thickness 220 may be substantially uniform. In other embodiments, the thickness 220 of the second layer 204 may vary. In some embodiments, the thickness 220 may be between about 5 mm and about 30 mm. In other embodiments, the thickness 220 may be thinner or thicker than the stated range as needed for the particular application of the dressing 104. In a preferred embodiment, the thickness 220 may be about 8 mm. In some embodiments, individual portions of the second layer 204 may have a minimal tolerance from the thickness 220. In some embodiments, the thickness 220 may have a tolerance of about 2 mm. In some embodiments, the thickness 220 may be between about 6 mm and about 10 mm. The second layer 204 may be flexible so that the second layer 204 can be contoured to a surface of a tissue site.

[0071] In some embodiments, the second layer 204 may be formed from thermoplastic elastomers (TPE), such as styrene ethylene butylene styrene (SEBS) copolymers, or thermoplastic polyurethane (TPU). The second layer 204 may be formed by combining sheets of TPE or TPU. In some embodiments, the sheets of TPE or TPU may be bonded, welded, adhered, or otherwise coupled to one another. For example, in some embodiments, the sheets of TPE or TPU may be welded using radiant heat, radio-frequency welding, or laser welding. Supracor, Inc., Hexacor, Ltd., Hexcel Corp., and Econocorp, Inc. may produce suitable TPE or TPU sheets for the formation of the second layer 204. In some embodiments, sheets of TPE or TPU having a thickness between about 0.2 mm and about 2.0 mm may be used to form a structure having the thickness 220. In some embodiments, the second layer 204 may be formed from a 3D textile, also referred to as a spacer fabric. Suitable 3D textiles may be produced by Heathcoat Fabrics, Ltd., Baltex, and Mueller Textil Group. The second layer 204 can also be formed from polyurethane, silicone, polyvinyl alcohol, and metals, such as copper, tin, silver or other beneficial metals.

[0072] In some embodiments, the second layer 204 may be formed from a foam. For example, cellular foam, open -cell foam, reticulated foam, or porous tissue collections, may be used to form the second layer 204. In some embodiments, the second layer 204 may be formed of V.A.C. ^® GRANUFOAM™ Dressing, grey foam, or a type of Zotefoams. Grey foam may be a polyester polyurethane foam having about 60 pores per inch (ppi). Zotefoams may be a closed-cell crosslinked polyolefin foam. In one non limiting example, the second layer 204 may be an open-cell, reticulated polyurethane foam such as V.A.C. ^® GRANUFOAM™ Dressing available from Kinetic Concepts, Inc. of San Antonio, Texas; in other embodiments, the second layer 204 may be an open -cell, reticulated polyurethane foam such as a V.A.C. VERAFLO™ dressing, also available from Kinetic Concepts, Inc., of San Antonio, Texas. In some embodiments, the second layer 204 may have a 25% compression load deflection of at least 0.35 pounds per square inch, and the 65% compression load deflection may be at least 0.43 pounds per square inch. In some embodiments, the tensile strength of the second layer 204 may be at least 10 pounds per square inch. The second layer 204 may have a tear strength of at least 2.5 pounds per inch. [0073] In some embodiments, the second layer 204 may be formed from a foam that is mechanically or chemically compressed, often as part of a thermoforming process, to increase the density of the foam at ambient pressure. A foam that is mechanically or chemically compressed may be referred to as a compressed foam or a felted foam. A compressed foam may be characterized by a firmness factor (FF) that is defined as a ratio of the density of a foam in a compressed state to the density of the same foam in an uncompressed state. For example, a firmness factor (FF) of 5 may refer to a compressed foam having a density at ambient pressure that is five times greater than a density of the same foam in an uncompressed state at ambient pressure. Generally, a compressed or felted foam may have a firmness factor greater than 1

[0074] Mechanically or chemically compressing a foam may reduce a thickness of the foam at ambient pressure when compared to the same foam that has not been compressed. Reducing a thickness of a foam by mechanical or chemical compression may increase a density of the foam, which may increase the firmness factor (FF) of the foam. Increasing the firmness factor (FF) of a foam may increase a stiffness of the foam in a direction that is parallel to a thickness of the foam. For example, increasing a firmness factor (FF) of the second layer 204 may increase a stiffness of the second layer 204 in a direction that is parallel to the thickness 220 of the second layer 204. In some embodiments, a compressed foam may be a compressed V.A.C. ^® GRANUFOAM™ Dressing. V.A.C. ^® GRANUFOAM™ Dressing may have a density of about 0.03 grams per centimeter³ (g/cm³) in its uncompressed state. If the V.A.C.^® GRANUFOAM™ Dressing is compressed to have a firmness factor (FF) of 5, the V.A.C.^® GRANUFOAM™ Dressing may be compressed until the density of the V.A.C.^® GRANUFOAM™ Dressing is about 0.15g/cm³. V.A.C. VERAFLO™ dressing may also be compressed to form a compressed foam having afirmness factor (FF) up to 5. For example, V.A.C. VERAFLO™ dressing may have a density of about 0.02 g/cm³. The density can increase to between about 0.06 g/cm³ to about 0.10 g/cm³ if the V.A.C. VERAFLO™ dressing is felted to a firmness factor of about 3 to about 5. In some embodiments, the second layer 204 may have a thickness between about 4 mm and about 15 mm, and more specifically, about 8 mm at ambient pressure. In an exemplary embodiment, if the thickness 220 of the second layer 204 is about 8 mm, and the second layer 204 is positioned within the sealed environment and subjected to negative pressure of about -115 mm Hg to about -135 mm Hg, the thickness 220 of the second layer 204 may be between about 1 mm and about 5 mm and, generally, greater than about 3 mm.

[0075] The firmness factor (FF) may also be used to compare compressed foam materials with non-foam materials. For example, a Supracor® material may have a firmness factor (FF) that allows Supracor® to be compared to compressed foams. In some embodiments, the firmness factor (FF) for a non-foam material may represent that the non-foam material has a stiffness that is equivalent to a stiffness of a compressed foam having the same firmness factor. For example, if a second layer 204 is formed from Supracor®, as illustrated in Table 1 below, the second layer 204 may have a stiffness that is about the same as the stiffness of a compressed V.A.C.^® GRANUFOAM™ Dressing material having a firmness factor (FF) of 3.

[0076] Generally, if a compressed foam is subjected to negative pressure, the compressed foam exhibits less deformation than a similar uncompressed foam. If the second layer 204 is formed of a compressed foam, the thickness 220 of the second layer 204 may deform less than if the second layer 204 is formed of a comparable uncompressed foam. The decrease in deformation may be caused by the increased stiffness as reflected by the firmness factor (FF). If subjected to the stress of negative pressure, the second layer 204 that is formed of compressed foam may flatten less than the second layer 204 that is formed from uncompressed foam. Consequently, if negative pressure is applied to the second layer 204, the stiffness of the second layer 204 in the direction parallel to the thickness 220 of the second layer 204 allows the second layer 204 to be more compliant or compressible in other directions, e.g., a direction perpendicular to the thickness 220. The foam material used to form a compressed foam may be either hydrophobic or hydrophilic. The foam material used to form a compressed foam may also be either reticulated or un-reticulated. The pore size of a foam material may vary according to needs of the second layer 204 and the amount of compression of the foam. For example, in some embodiments, an uncompressed foam may have pore sizes in a range of about 400 microns to about 600 microns. If the same foam is compressed, the pore sizes may be smaller than when the foam is in its uncompressed state.

[0077] Figure 2 also illustrates one example of a fluid conductor 224 and a dressing interface 226. As shown in the example of Figure 2, the fluid conductor 224 may be a flexible tube, which can be fluidly coupled on one end to the dressing interface 226. The dressing interface 226 may be an elbow connector, as shown in the example of Figure 2, which can be placed over an aperture 228 in the cover 116 to provide a fluid path between the fluid conductor 224 and the tissue interface 114.

[0078] Figure 3 is a perspective view of the tissue interface 114 illustrating additional details that may be associated with some embodiments. The first layer 202 may be coupled to the second layer 204. For example, the first layer 202 may be bonded, adhered, or preferably welded to the second layer 204. In some embodiments, the tissue interface 114 includes a plurality of welds 302 coupling the first layer 202 to the second layer 204. Welding can include radio-frequency (RF) welding, adhesive welding, localized heat welding, friction welding, or other welding techniques to form the plurality of welds 302 coupling the first layer 202 to the second layer 204. The plurality of welds 302 can be continuous welds. Continuous welds may be one or more welds that have at least one edge in contact with an adjacent weld. For example, the plurality of welds 302 can extend across an entirety of the surface of the first layer 202 adjacent to the second layer 204 so that the plurality of welds 302 form a continuous coupling across the contacting surfaces. In some embodiments, the plurality of welds 302 may be non-continuous welds or discrete welds. Non-continuous welds may be a plurality of welds that each have edges spaced from adjacent welds so that the edges of the adjacent welds do not contact. For example, the plurality of welds 302 may comprise a plurality of discrete coupling locations. For non-continuous welds, at a location of a weld 302, the first layer 202 may be coupled or joined to the second layer 204, and at locations lacking a weld 302, the first layer 202 may be in contact with the second layer 204 but not joined to the second layer 204. Preferably, the less than 1% of the surface area of the first layer 202 and the second layer 204 are coupled to each other.

[0079] In some embodiments, the tissue interface 114 may also include a plurality of raised portions, poufs, or projections 304. In some embodiments, between about 90% and about 99% of the surface area of the tissue interface 114 may comprise or consist essentially of the projections 304. Each projection 304 of the plurality of projections 304 may be a region of the tissue interface 114 having a different elevation relative to an elevation of the tissue interface 114 at the plurality of welds 302. In some embodiments, each projection 304 can have an elevation of about 1 mm to about 10 mm relative to surrounding areas of the tissue interface 114. In some embodiments, each projection 304 may surround or outline a through-hole 212 and a through-hole 218. In some embodiments, the welds 302 are located in the tissue interface 114 so that each projection 304 of the plurality of projections 304 has a substantially circular shape. In other embodiments, the projections 304 may be linear, elliptical, or polygonal. The plurality of projections 304 may have an average effective diameter between about 3 mm and about 30 mm and, in some embodiments, between about 6 mm and about 14 mm. The plurality of projections 304 may also have varied shapes within a same tissue interface 114.

[0080] Figure 4 is a sectional view of the tissue interface 114 of Figure 3 taken along line 4 — 4, illustrating additional details that may be associated with some embodiments. As illustrated in Figure 4, each weld 302 of the plurality of welds 302 may have a length 402. The length 402 can be a distance between adjacent projections 304 of the tissue interface 114. Where the plurality of welds 302 form a continuous weld across the tissue interface 114, the length 402 of each weld 302 can define a spacing of the projections 304. In some embodiments, the length 402 can be between about 2 mm and about 15 mm. In some embodiments, the length 402 of each weld 302 can be uniform. For example, each weld 302 can have a same length 402. The length 402 of each weld 302 can also be non-uniform. For example, some welds 302 can have a length 402A and other welds 302 can have a length 402B. The length 402A and the length 402B can also very between projections 304 in a first direction and projections 304 in a second direction. For example, the length 402A may be different than the length 402B in the second direction orthogonal to the first direction. In some embodiments, the restrictions 210 may be disposed in the plurality of welds 302, forming a plurality of weld slits.

[0081] In some embodiments, the through -holes 212 of the first layer 202 and the through-holes 218 of the second layer 204 may be coincident. For example, the through-holes 212 and the through-holes 218 may have the same or similar average effective diameters. The first layer 202 can be coupled to the second layer 204 so that edges of the through-holes 212 align with edges of the through-holes 218. In some embodiments, the through-holes 212 and the through-holes 218 can be formed substantially simultaneously. For example, the plurality of welds 302 and the plurality of projections 304 can be formed, coupling the first layer 202 to the second layer 204. Following coupling of the first layer 202 to the second layer 204, the through-holes 212 and the through-holes 218 can be formed in the tissue interface 114. For example, portions of the first layer 202 and the second layer 204 can be removed from the tissue interface 114 by cutting, melting, punching, vaporizing, or other suitable techniques to form the through-holes 212 and the through-holes 218 at the desired locations. In some embodiments, the through-holes 218 and the through- holes 212 may be located at a projection 304. The through-holes 218, the through-holes 212, and the projections 304 may have a same pitch. In other embodiments, the through-holes 218, the through-holes 212, and the projections 304 may have a different pitch. In some embodiments, the tissue interface 114 can be formed without the through-holes 218, without the through-holes 212, or without both. The projections 304 may be filled. For example, the through-holes 212 and the through-holes 218 may not be formed in the first layer 202 and the second layer 204, respectively, leaving the projections 304 having foam therein.

[0082] In some embodiments, each projection 304 may have a same height. For example, the tissue interface 114 may have portions having a thickness 406 that generally coincides with the plurality of welds 302. The thickness 406 may be less than the thickness 220. The thickness 220 may coincide with the plurality of projections 304. In some embodiments, the thickness 406 may be between about 2 mm and about 300 mm. The thickness 220 may be between about 100 mm and about 300 mm. In some embodiments, a difference between the thickness 220 and the thickness 406 may be between about 1 mm and about 10 mm. In some embodiments, the second layer 204 can be formed from a felted foam. In some embodiments, the second layer 204 can have portions having different amounts of felting. For example, the second layer 204 can have a first portion having a first density coinciding with a first amount of felting, and a second portion having a second density coinciding with a second amount of felting. In some embodiments, the first portion can include the projections 304 having the thickness 220 at a first density. In some embodiments, the density of the foam forming the second layer 204 at the projections 304 can be between about 5kg/m³ and about 100 kg/m³ and, preferably, between about 20 kg/m³ and about 70 kg/m³. The second portion can include the plurality of welds 302 having the thickness 406 at a second density. In some embodiments, the density of the foam forming the second layer 204 at the welds 302 can be between about 15kg/m³ and about 400 kg/m³ and, preferably, between about 50 kg/m³ and about 210 kg/m³. The variation in density or felting can be caused by the coupling of the first layer 202 to the second layer 204. For example, welding of the first layer 202 to the second layer 204 may cause localized heating and compression of the second layer 204, causing increased felting at the weld 302. In some embodiments, the firmness factor (FF) or felting level at the weld 302 can be between about 3 and about 10 and preferably between about 3 and about 5. Locations where the first layer 202 covers the second layer 204 without welding of the first layer 202 to the second layer 204, for example, at the plurality of projections 304, may be free of localized heating and compression associated with formation of the plurality of welds 302.

[0083] In some embodiments, each projection 304 of the plurality of projections 304 may have a same average effective diameter. For example, each projection 304 can have an average effective diameter between about 3 mm and about 30 mm and preferably between about 6 mm and about 14 mm. In other embodiments, each projection 304 of the plurality of projections 304 may have varied average effective diameters.

[0084] In some embodiments, a plurality of perforations 404 can extend through the first layer 202 and the second layer 204. The plurality of perforations 404 can comprise slits, cuts, or other openings through the first layer 202 and the second layer 204. The plurality of perforations 404 may separate the tissue interface 114 into separate portions along the plurality of perforations 404. In some embodiments, the tissue interface 114 can be sized along the plurality of perforations 404. For example, the tissue interface 114 can be tom along the plurality of perforations 404 to separate the tissue interface 114 into two portions.

[0085] Figure 5 is a bottom plan view of the issue interface 114 illustrating additional details that may be associated with some embodiments. As illustrated in Figure 5, the tissue interface 114 may include the plurality of perforations 404. In some embodiments, the perforations 404 may be aligned parallel to a straight edge of the tissue interface 114. In other embodiments, the perforations 404 may be positioned at an angle to a straight edge of the tissue interface 114 or arranged to form shapes within the tissue interface 114. In some embodiments, each perforation 404 of the plurality of perforations 404 can have a length between about 2 mm and about 3 mm. In some embodiments, the plurality of perforations 404 may be distributed across the tissue interface 114 in parallel rows. For example, the plurality of perforations 404 can be distributed in a first row 502, a second row 504, and a third row 506. The plurality of perforations 404 can have a pitch of about 10 mm in each row. The tissue interface 114 can also include a plurality of perforations 404 arranged in rows perpendicular to the first row 502, the second row 504, and the third row 506. For example, the plurality of perforations 404 can be distributed in a fourth row 508 and a fifth row 510 that are perpendicular to the first row 502, the second row 504, and the third row 506. In other embodiments, the fourth row 508 and the fifth row 510 can be arranged at other angles to the first row 502, the second row 504, and the third row 506 or arranged to form shapes within the tissue interface 114. The first row 502, the second row 504, the third row 506, the fourth row 508, and the fifth row 510 can form tear lines in the tissue interface 114. The tissue interface 114 can be separated into two or more sections, permitting the tissue interface 114 to be sized to fit a desired tissue site. In other embodiments, the tissue interface 114 can have more or fewer rows formed by the plurality of perforations 404. [0086] Figure 6 is a sectional view of a portion of the first layer 202 and the second layer 204, illustrating additional details that may be associated with some embodiments. The first layer 202 and the second layer 204 may be placed at a tissue site 602 having debris 604 covering subcutaneous tissue 606. For example, a clinician may place the tissue interface 114 having the first layer 202 and the second layer 204 at the tissue site 602 and cover the tissue interface 114 and the tissue site 602 with the cover 116. In some embodiments, the tissue interface 114 may be packaged in a sterile container that the clinician may open and remove. The tissue interface 114 having the first layer 202 and the second layer 204 may be removed as a single piece for placement at the tissue site 602.

[0087] In some embodiments, the tissue interface 114 may have a length and width that is greater than an opening of the tissue site 602. The tissue interface 114 may be sized to permit the tissue interface 114 to be passed through the opening of the tissue site 602 to be placed adjacent to the debris 604. Sizing can include removing a portion of the tissue interface 114, for example, by cutting, tearing, melting, dissolving, vaporizing, or otherwise separating a portion of the tissue interface 114 from remaining portions of the tissue interface 114. During sizing of the tissue interface 114, the first layer 202 and the second layer 204 may be sized at substantially the same time. For example, the first layer 202 and the second layer 204 may be tom or cut along the perforations 404. Following sizing of the tissue interface 114, the tissue interface 114 can be positioned at the tissue site 602. For example, the tissue interface 114 can be oriented so that the first layer 202 is adjacent to a surface of the tissue site 602. Preferably, the first surface 206 of the first layer 202 can contact the tissue site 602. In some embodiments, the first layer 202 at the projections 304 can contact the debris 604 at the tissue site 602. The difference between the thickness 220 at the plurality of projections 304 and the thickness 406 at the plurality of welds 302 can cause the first layer 202 to be spaced apart from the debris 604 at the plurality of welds 302. In some embodiments, there may be gaps 608 between the first layer 202 at the plurality of welds 302 and the debris 604. In other embodiments, variation in topography of the tissue site 602 may cause a size of the gaps 608 to vary across the tissue interface 114 and the tissue site 602. After placement of the tissue interface 114 at the tissue site 602, the cover 116 may be placed over the second layer 204 to provide a sealed environment for the application of negative-pressure therapy or instillation therapy.

[0088] Figure 7 is a sectional view of a portion of the dressing 104 during negative-pressure therapy, illustrating additional details that may be associated with some embodiments. For example, Figure 7 may illustrate a moment in time where a pressure in a sealed environment formed by the cover 116 may be about -125 mm Hg of negative pressure. In response to the application of negative pressure, the second layer 204 may not compress or may compress negligibly. In some embodiments, negative pressure in the sealed environment can generate concentrated stresses in the debris 604 adjacent to the through-holes 212 in the first layer 202 and the through-holes 218 in the second layer 204. The concentrated stresses can cause macro-deformations of the debris 604 and the subcutaneous tissue 606 that draws portions of the debris 604 and the subcutaneous tissue 606 into the through-holes 212 and the through-holes 218. Similarly, negative pressure in the sealed environment can generate concentrated stresses in the debris 604 adjacent to the gaps 608. For example, the difference between the thickness 220 at the plurality of projections 304 and the thickness 406 at the plurality of welds 302 can cause macro-deformation of the debris 604 and the subcutaneous tissue 606 that draws portions of the debris 604 and the subcutaneous tissue 606 into the gaps 608.

[0089] Figure 8 is a detail view of the first layer 202 and the second layer 204, illustrating additional details of the operation of the tissue interface 114 during negative-pressure therapy. The plurality of projections 304 may create macro-pressure points in portions of the debris 604 and the subcutaneous tissue 606 that are in contact with the first surface 206 of the first layer 202, causing tissue puckering and the formation of nodules 802 in the debris 604 and the subcutaneous tissue 606 that is adjacent to the plurality of welds 302. Similarly, the through-holes 212 and the through-holes 218 may create macro pressure points in portions of the debris 604 and the subcutaneous tissue 606 that are adjacent to the plurality of projections 304. The macro -pres sure points can also cause tissue puckering and the formation of nodules 804 in the debris 604 and the subcutaneous tissue 606 that is adjacent to the plurality of projections 304.

[0090] A height of the nodules 802 and the nodules 804 over the surrounding tissue may be selected to maximize disruption of debris 604 and minimize damage to subcutaneous tissue 606 or other desired tissue. Generally, the pressure in the sealed environment can exert a force that is proportional to the area over which the pressure is applied. At the through-holes 218 of the second layer 204 and the plurality of welds 302, the force may be concentrated as the resistance to the application of the pressure is less than in the plurality of projections 304 surrounding the through-holes 212 and the through-holes 218. Similarly, at the gaps 608, the force may be concentrated as the resistance to the application of the pressure is less than in the plurality of projections 304 but greater than the resistance to the application of pressure in the through-holes 212 and the through-holes 218. In response to the force generated by the pressure at the gaps 608, the debris 604 and the subcutaneous tissue 606 that forms the nodules 802 may be drawn into the gaps 608 adjacent to the plurality of welds 302. In some embodiments where the negative pressure in the sealed environment may cause tearing, the difference in the thickness 220 and the thickness 406 of the second layer 204 may be selected to limit the height of the nodules 802 over the surrounding tissue. In some embodiments, the height of the nodules 802 may be limited to a height that is less than the thickness 220 of the second layer 204. In an exemplary embodiment, the thickness 220 of the second layer 204 may be about 7 mm and the thickness 406 of the second layer 204 may be about 4 mm. During the application of negative pressure, the height of the nodules 802 may be limited to about 3 mm. By controlling the height of the nodules 802 and controlling the thickness 220 and the thickness 406 of the second layer 204, the aggressiveness of disruption to the debris 604 and tearing can be controlled at the nodules 802.

[0091] At the through-holes 212 and the through-holes 218, the debris 604 and the subcutaneous tissue 606 that forms the nodules 804 may be drawn and into and through the through-holes 212 and the through-holes 218 until the force applied by the pressure is equalized by the reactive force of the debris 604 and the subcutaneous tissue 606. In some embodiments, the height of the nodules 804 can be controlled by controlling an expected compression of the second layer 204 during negative-pressure therapy. For example, the second layer 204 may have the thickness 220 of about 8 mm. If the second layer 204 is formed from a compressed foam, the firmness factor of the second layer 204 may be higher; however, the second layer 204 may still reduce in thickness in response to negative pressure in the sealed environment. In one embodiment, application of negative pressure of between about -50 mm Hg and about -350 mm Hg, between about -100 mm Hg and about -250 mm Hg and, more specifically, about -125 mm Hg in the sealed environment may reduce the thickness 220 at the projections 304 from about 8 mm to about 3 mm. The height of the nodules 804 may be limited to be no greater than the thickness 220 of the second layer 204 during negative-pressure therapy, for example, about 3 mm. By controlling the height of the nodules 804, the forces applied to the debris 604 by the tissue interface 114 can be adjusted and the degree that the debris 604 is stretched and the nodules 804 can be varied.

[0092] Disruption of the debris 604 can be caused, at least in part, by the concentrated forces applied to the debris 604. The forces applied to the debris 604 can be a function of the negative pressure supplied to the sealed environment and the area of each through-hole 218 and the area of the plurality of welds 302. For example, if the negative pressure supplied to the sealed environment is about -125 mm Hg and the diameter of each through-hole 218 is about 5 mm, the force applied at each through-hole 218 is about 0.07 lbs. If the diameter of each through-hole 218 is increased to about 8 mm, the force applied at each through -hole 218 can increase up to 6 times. Generally, the relationship between the diameter of each through-hole 218 and the applied force at each through-hole 218 is not linear and can increase exponentially with an increase in diameter. Similarly, variations in the area of the plurality of welds 302 relative to area the plurality of projections 304 can cause variations in the force applied at the plurality of welds 302.

[0093] In some embodiments, the formation of the nodules 802 and the nodules 804 can cause the debris 604 to remain in contact with a tissue interface 114 during negative pressure therapy. For example, the nodules 802 may contact the sidewalls of the through-holes 212 of the first layer 202 and the through- holes 218 of the second layer 204. In some embodiments, formation of the nodules 802 may lift debris 604 and particulates off of the surrounding tissue, operating in a piston-like manner to move debris 604 toward the tissue interface 114 and out of the sealed environment. [0094] In some embodiments, the tissue interface 114 can provide variations in the aggressiveness of the tissue disruption. For example, the tissue interface 114 can provide a first level of disruption to the debris 604 at the nodules 802, and the tissue interface 114 can provide a second level of disruption to the debris 604 at the nodules 804. The tissue interface 114 can be used to address areas of a tissue site 602 that may need varying levels of disruption.

[0095] In response to the return of the sealed environment to ambient pressure by venting the sealed environment, the nodules 802 and the nodules 804 may return to the position shown in Figure 6. In some embodiments, repeated application of negative-pressure therapy and instillation therapy while the tissue interface 114 is disposed over the debris 604 may disrupt the debris 604, allowing the debris 604 to be removed during dressing changes. In other embodiments, the tissue interface 114 may disrupt the debris 604 so that the debris 604 can be removed by negative pressure. In still other embodiments, the tissue interface 114 may disrupt the debris 604, aiding removal of the debris 604 during debridement processes. With each cycle of therapy, the tissue interface 114 may form nodules 802 and nodules 804 in the debris 604. The formation of the nodules 802 and the nodules 804 and release of the nodules 802 and the nodules 804 by the tissue interface 114 during therapy may disrupt the debris 604. With each subsequent cycle of therapy, disruption of the debris 604 can be increased.

[0096] In some embodiments, the negative pressure applied by the negative-pressure source 102 may be cycled rapidly. For example, negative pressure may be supplied for a few seconds, then vented for a few seconds, causing a pulsation of negative pressure in the sealed environment. The pulsation of the negative pressure can pulsate the nodules 802 and the nodules 804, causing further disruption of the debris 604.

[0097] In some embodiments, the cyclical application of instillation therapy and negative pressure therapy may cause micro-floating. For example, negative pressure may be applied to the sealed environment during a negative-pressure therapy cycle. Following the conclusion of the negative -pres sure therapy cycle, instillation fluid may be supplied during the instillation therapy cycle. The instillation fluid may cause the tissue interface 114 to float relative to the debris. As the tissue interface 114 floats, it may change position relative to the position the tissue interface 114 occupied during the negative-pressure therapy cycle. The position change may cause the tissue interface 114 to engage a slightly different portion of the debris 604 during the next negative-pressure therapy cycle, aiding disruption of the debris 604 and the application of antimicrobial/antibacterial agents by the first layer 202. In this manner, the welds 302 and the projections 304 may permit the tissue interface 114 to create differential pressure on the tissue site 602, thereby creating tissue deformation when used during negative-pressure and instillation therapy.

[0098] Figure 9 is an assembly view of an example of the dressing 104 of Figure 1, illustrating additional details that may be associated with some embodiments. In the example of Figure 9, the tissue interface 114 comprises the first layer 202, the second layer 204, and a third layer 902. In some embodiments, the second surface 208 of the first layer 202 may be adjacent to the first surface 214 of the second layer 204, and the third layer 902 may be adjacent to the second surface 216 of the second layer 204. In some embodiments, the first layer 202 may be free of the through-holes 212, and the second layer 204 may be free of the through-holes 218.

[0099] The third layer 902 may have a first surface 904 and a second surface 906. In some embodiments, the third layer 902 may comprise or consist essentially of a means for controlling or managing fluid flow. In some embodiments, the third layer 902 may be similar to and include the properties of the first layer 202 described above with respect to Figure 2. For example, the third layer 902 may comprise or consist essentially of a polymer film. The surface of the third layer 902 may have a substantially flat surface, with height variations limited to 0.2 millimeters over a centimeter. In some embodiments, the third layer 902 may comprise or consist essentially of a hydrophobic material. The third layer 902 may also be suitable for bonding to other layers, including the second layer 204.

[00100] As illustrated in the example of Figure 9, the third layer 902 may have one or more fluid restrictions 908, which can be distributed uniformly or randomly across the third layer 902. The fluid restrictions 908 may be similar to and include the properties of the fluid restrictions 210 described above with respect to Figure 2. For example, the fluid restrictions 908 may be bi-directional and pressure- responsive. Each of the fluid restrictions 908 generally may comprise or consist essentially of an elastic passage that is normally unstrained to substantially reduce liquid flow, and can expand or open in response to a pressure gradient. Some embodiments of the fluid restrictions 908 may comprise or consist essentially of one or more slits, slots or combinations of slits and slots. In some embodiments, the fluid restrictions 908 may comprise or consist essentially of perforations in the third layer 902. Additionally or alternatively, one or more of the fluid restrictions 908 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 material may be a suitable valve for some applications. In some embodiments, the fluid restrictions 908 extend through the third layer 902.

[00101] As illustrated in the example of Figure 9, in some embodiments, the dressing 104 may include the fluid conductor 224 and the dressing interface 226. The dressing interface 226 may be an elbow connector, as shown in the example of Figure 9, which can be placed over the aperture 228 in the cover 116 to provide a fluid path between the fluid conductor 224 and the tissue interface 114.

[00102] Figure 10 is a sectional view of the tissue interface 114 taken along line 10 — 10 of Figure 9 and illustrating additional details shown in some embodiments. In some embodiments, the first layer 202 may be coupled to the second layer 204. In some embodiments, the tissue interface 114 includes the plurality of welds 302 coupling the first layer 202 to the second layer 204 and forming the plurality of projections 304.

[00103] In some embodiments, the first surface 904 of the third layer 902 is coupled to the second surface 216 of the second layer 204. For example, the third layer 902 may be bonded, adhered, or preferably welded to the second layer 204. In some embodiments, the tissue interface 114 includes a plurality of welds 1002 coupling the third layer 902 to the second layer 204. Welding can include radio-frequency (RF) welding, adhesive welding, localized heat welding, friction welding, or other welding techniques to form the plurality of welds 302 coupling the third layer 902 to the second layer 204. The plurality of welds 1002 can be continuous welds. For example, the plurality of welds 1002 can extend across an entirety of the surface of the third layer 902 adjacent to the second layer 204 so that the plurality of welds 1002 form a continuous coupling across the contacting surfaces. In some embodiments, the plurality of welds 1002 may be non-continuous welds. For example, the plurality of welds 1002 may comprise a plurality of discrete coupling locations. For non-continuous welds, at a location of a weld 1002, the third layer 902 may be coupled or joined to the second layer 204, and at locations lacking a weld 1002, the third layer 902 may be in contact with the second layer 204 but not joined to the second layer 204.

[00104] In some embodiments, the tissue interface 114 may also include a plurality of poufs or projections 1004. Each projection 1004 of the plurality of projections 1004 may be a region of the tissue interface 114 having a different elevation relative to an elevation of the tissue interface 114 at the plurality of welds 1002. In some embodiments, the welds 1002 are located in the tissue interface 114 so that each projection 1004 of the plurality of projections 1004 has a substantially circular shape. In other embodiments, the projections 1004 may be linear, elliptical, or polygonal. The plurality of projections 1004 may have an average effective diameter between about 3 mm and about 30 mm and preferably between about 6 mm and about 14 mm. The plurality of projections 1004 may also have varied shapes within a same tissue interface 114.

[00105] In some embodiments, each weld 1002 of the plurality of welds 1002 may have a length 1006. The length 1006 can be between about 2 mm and about 15 mm. In some embodiments, the length 1006 of each weld 1002 can be uniform. For example, each weld 1002 can have a same length 1006. The length 1006 of each weld 1002 can also be non-uniform. For example, some welds 1002 can have a length 1006A and other welds 1002 can have a length 1006B. In some embodiments, the fluid restrictions 908 may be disposed in the plurality of welds 1002.

[00106] In some embodiments, the plurality of projections 304 and the plurality of projections 1004 can be coincident. For example, the plurality of welds 302 and the plurality of projections 304 can be formed, coupling the first layer 202 to the second layer 204. Following coupling of the first layer 202 to the second layer 204, the plurality of welds 1002 and the plurality of projections 1004 can be formed, coupling the third layer 902 to the second layer 204. In other embodiments, the plurality of projections 304 and the plurality of projections 1004 can be formed simultaneously or nearly simultaneously by coupling the first layer 202 and the third layer 902 to the second layer 204 at substantially the same time. In some embodiments, each projection 1004 may have a same height and average effective diameter. In other embodiments, each projection 1004 of the plurality of projections 1004 may have a varied height and average effective diameter.

[00107] In some embodiments, the plurality of projections 304 and the plurality of projections 1004 can include a plurality of depressions 1008. For example, each projection 304 and projection 1004 can include a depression 1008. The depression 1008 can be a depressed region or cavity formed in a projection, for example, a projection 304 of a projection 1004. In some embodiments, the first layer 202 and the third layer 902 can be welded to the second layer 204 at each depression 1008. In other embodiments, the first layer 202 and the third layer 902 may be uncoupled to the second layer 204 at each depression 1008. In some embodiments, each depression 1008 has a substantially flat surface surrounded by a rim formed by a projection 304 or a projection 1004. In some embodiments, each depression 1008 can have a surface area between about 2 cm² and about 10 cm² and having an average effective diameter between about 1.6 cm and about 3.6 cm.

[00108] In some embodiments, the second layer 204 may have a thickness 1010. The thickness 1010 may be less than the thickness 220. The thickness 1010 may coincide with the plurality of welds 302 and the plurality of welds 1002, and the thickness 220 may coincide with the plurality of projections 304 and the plurality of projections 1004. In some embodiments, the thickness 1010 may be associated with the plurality of welds 302 and the plurality of welds 1002, and the thickness 220 may be associated with the plurality of projections 304 and the plurality of projections 1004. At locations of the thickness 1010, the second layer 204 may have a higher level of felting than at locations of the thickness 220. For example, welding of the first layer 202 and the third layer 902 to the second layer 204 may cause localized heating and compression of the second layer 204, causing increased felting and increased density of the foam material of the second layer 204 at the welds 302 and the welds 1002. Locations where the first layer 202 and the third layer 902 cover the second layer 204 without welding of the first layer 202 and the third layer 902 to the second layer 204, for example, at the plurality of projections 304 and the plurality of projections 1004, may be free of localized heating and compression associated with formation of the plurality of welds 302.

[00109] The second layer 204 may also have a thickness 1012. The thickness 1012 may be less than the thickness 220. In some embodiments, the thickness 1012 may be greater than the thickness 1010. In other embodiments, the thickness 1012 may be less than the thickness 1010. The thickness 1012 may coincide with the depressions 1008. In some embodiments, the thickness 1012 may be associated with a higher level of felting of the second layer 204. For example, the second layer 204 may be subjected to localized heating and compression during formation of the depressions 1008 that increases the felting of the second layer 204. In some embodiments, the depressions 1008 can be formed prior to coupling of the first layer 202 and the third layer 902 to the second layer 204. For example, the second layer 204 can be felted at the locations of the depressions 1008, increasing the density of the second layer 204 at the locations of the depressions 1008 and forming locations having the thickness 1012. Following the felting of the second layer 204 to form the depressions 1008, the first layer 202 and the third layer 902 can be coupled to the second layer 204.

[00110] Figure 11 is a perspective view of a bottom of another example of the tissue interface 114 illustrating additional details that may be associated with some embodiments. The tissue interface 114 can include the first layer 202 and the third layer 902 coupled to the second layer 204. In some embodiments, the plurality of projections 304 may be non-uniform. For example, the plurality of projections 304 may have a first plurality of projections 1104 having different average effective diameters than a second plurality of projections 1106. In some embodiments, the depressions 1008 can include a plurality of through-holes 1102. In some embodiments, each through -hole 1102 can be polygonal shaped, for example, rectangular. In other embodiments, each through-hole 1102 can have a circular, elliptical, or amorphous shape. In some embodiments, each depression 1008 can include five through-holes 1102 arranged circumferentially about a center of the depression 1008. A short edge of a rectangular shaped through-hole 1102 can positioned proximate to the center of the depression 1008, and a long edge can extend toward a periphery of the depression 1008. In other embodiments, more or fewer through-holes 1102 can be formed in each depression 1008.

[00111] Figure 12 is a sectional view of the tissue interface 114 of Figure 11 taken along line 12 — 12 illustrating additional details that may be associated with some embodiments. In some embodiments, the first plurality of proj ections 1104 have a larger average effective diameter than the second plurality of projections 1106. For example, an average difference in the average effective diameters of the first plurality of projections 1104 and the second plurality of projections 1106 may be between about 11 mm and about 30 mm and have an average area between about 1 cm² and about 7 cm². In some embodiments, portions of a tissue site may benefit from additional tissue deformation. The tissue interface 114 can be tailored to have more projections per unit area to cause additional tissue deformation at those areas. The portions of the tissue interface 114 having more projections per unit area may have projections, such as the plurality of second projections 1106 having smaller diameters than the plurality of first projections 1104 where there are fewer projections per unit area. Similarly, the plurality of projections 1004 may have a first plurality of projections 1202 having different average effective diameters than a second plurality of projections 1204. In some embodiments, the first plurality of projections 1202 have a larger average effective diameter than the second plurality of projections 1204. The first plurality of projections 1202 may coincide with the first plurality of projections 1104, and the second plurality of projections 1204 may coincide with the second plurality of projections 1106. In other embodiments, the projections may be offset from corresponding projections on an opposite side of the tissue interface 114. The through -holes 1102 can extend through the first layer 202, the second layer 204, and the third layer 902.

[00112] Figure 13 is a perspective view of another embodiment of the tissue interface 114 of Figure 1 illustrating additional details that may be associated with some embodiments. The tissue interface 114 can include a contact layer, such as a film layer 1302, and a plurality of tissue disruption members, such as a plurality of projections 1304. In some embodiments, the plurality of projections 1304 may be coupled to the film layer 1302.

[00113] The film layer 1302 may have a first surface 1306 and a second surface 1308. In some embodiments, the film layer 1302 may comprise or consist essentially of a means for controlling or managing fluid flow. In some embodiments, the film layer 1302 may comprise or consist essentially of an elastomeric material that is impermeable to liquid. For example, the film layer 1302 may comprise or consist essentially of a polymer film. The film layer 1302 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 film layer 1302 may have a substantially flat surface, with height variations limited to 0.2 millimeters over a centimeter.

[00114] In some embodiments, the film layer 1302 may comprise or consist essentially of a hydrophobic material. The hydrophobicity may vary, but may have a contact angle with water of at least ninety degrees. In some embodiments the hydrophobic material may have a contact angle with water of no more than 150 degrees. For example, the contact angle 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 FTAl25, FTA2OO, FTA2OOO, 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 film layer 1302 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.

[00115] The film layer 1302 may also be suitable for bonding to other layers, including the plurality of projections 1304. For example, the film layer 1302 may be adapted for welding to polyurethane foams using heat, radio frequency (RF) welding, or other methods to generate heat such as ultrasonic welding. RF welding may be particularly suitable for more polar materials, such as polyurethane, polyamides, polyesters and acrylates. Sacrificial polar interfaces may be used to facilitate RF welding of less polar film materials, such as polyethylene. The film layer 1302 may include hot melt films.

[00116] The area density of the film layer 1302 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.

[00117] In some embodiments, for example, the film layer 1302 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, polyvinyl chloride, polypropylene, polymethylpentene, polycarbonate, styreneics, silicones, fluoropolymers, cellophase, cellulose acetate, and other acetates. A thickness between 25 microns and 200 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, co-polyesters, 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 (EMA) film may also have suitable hydrophobic and welding properties for some configurations. In some embodiments, the film layer 1302 may be formed of a transparent polymer to aid in cutting. In some embodiments, the film layer 1302 can be printed with various information, such as product identification, instructions for placement, cutting or sizing, or numbers

[00118] As illustrated in the example of Figure 13, the film layer 1302 may have one or more fluid restrictions 1310, which can be distributed uniformly or randomly across the film layer 1302. The fluid restrictions 1310 may be bi-directional and pressure-responsive. For example, each of the fluid restrictions 1310 generally may comprise or consist essentially of an elastic passage that is normally unstrained to substantially reduce liquid flow, and can expand or open in response to a pressure gradient.

[00119] Some embodiments of the fluid restrictions 1310 may comprise or consist essentially of one or more slits, slots or combinations of slits and slots. In some examples, the fluid restrictions 1310 may comprise or consist of linear slots having a length less than 5 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 0.8 millimeters may be particularly suitable for many applications, and a tolerance of about 0.1 millimeters may also be acceptable. Such dimensions and tolerances may be achieved with a laser cutter, for example. In some embodiments, the fluid restrictions 1310 may be formed by ultrasonics or other heat means. 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.

[00120] In some embodiments, the fluid restrictions 1310 may comprise or consist essentially of perforations in the film layer 1302. Perforations may be formed by removing material from the film layer 1302. For example, perforations may be formed by cutting through the material, 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 1310 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 material may be a suitable valve for some applications. Fenestrations may also be formed by removing material, but the amount of material removed and the resulting dimensions of the fenestrations may be an order of magnitude less than perforations, and may not deform the edges. In some embodiments, the fluid restrictions 1310 extend through the film layer 1302.

[00121] The plurality of projections 1304 may be a plurality of discrete blocks or bodies coupled to the first surface 1306 of the film layer 1302. In some embodiments, each projection 1304 may be a discrete block having a substantially cuboid shape. In other embodiments, each projection 1304 may be spherical, pyramidal, polygonal, or amorphous shaped. Each projection 1304 may have a height 1312, a width 1314, and a thickness 1316. In some embodiments, the height 1312, the width 1314, and the thickness 1316 may be substantially uniform between projections 1304. In other embodiments, the height 1312, the width 1314, and the thickness 1316 of the plurality of projections 1304 may vary, provided the tissue interface 114 can manifold between about 25 mm Hg to about 400 mm Hg of negative pressure and preferably about 75 mm Hg and about 150 mm Hg of negative pressure across the tissue interface 114. In some embodiments, each of the height 1312, the width 1314, and the thickness 1316 may be between about 5 mm and about 30 mm. In other embodiments, the height 1312, the width 1314, and the thickness 1316 may be thinner or thicker than the stated range as needed for the particular application of the dressing 104. In a preferred embodiment, the height 1312 and the width 1314 may be between about 2 mm and about 30 mm and preferably between about 5 mm and about 15 mm, and the thickness 1316 may be between about 1 mm and about 40 mm and preferably between about 4 mm to about 14 mm. In some embodiments, individual portions of the plurality of projections 1304 may have a minimal tolerance from each of the height 1312, the width 1314, and the thickness 1316. In some embodiments, each of the height 1312, the width 1314, and the thickness 1316 may have a tolerance of about 2 mm.

[00122] The projections 1304 can be coupled to the film layer 1302 by welding, adhering, bonding, mechanical fixation, or other suitable means of securing the projections 1304 to the film layer 1302. In some embodiments, the projections 1304 may be disposed on the film layer 1302 with a regular pitch. For example, the projections 1304 may have a pitch 1318 in a first direction, and a pitch 1320 in a second direction perpendicular to the pitch 1318. In some embodiments, the pitch 1318 and the pitch 1320 may be between 10 mm and about 500 mm. In other embodiments, the pitch 1318 and the pitch 1320 may not be perpendicular to each other and can be at a non-perpendicular angle to an edge of the film layer 1302. In some embodiments, the projections 1304 can have an arcuate pitch 1318 disposing the projections 1304 circumferentially about a point on the film layer 1302. Where the pitch 1318 is arcuate, the projections 1304 can have a radial pitch 1320 disposing the projections 1304 radially outward from the point on the film layer 1302.

[00123] In some embodiments, the plurality of projections 1304 may be flexible so that the plurality of projections 1304 can be contoured to a surface of the tissue site. For example, the plurality of projections 1304 may be formed from thermoplastic elastomers (TPE), such as styrene ethylene butylene styrene (SEBS) copolymers, or thermoplastic polyurethane (TPU). The plurality of projections 1304 may be formed by combining sheets of TPE or TPU. In some embodiments, the sheets of TPE or TPU may be bonded, welded, adhered, or otherwise coupled to one another. For example, in some embodiments, the sheets of TPE or TPU may be welded using radiant heat, radio-frequency welding, or laser welding. Supracor, Inc., Hexacor, Ltd., Hexcel Corp., and Econocorp, Inc. may produce suitable TPE or TPU sheets for the formation of the plurality of projections 1304. In some embodiments, sheets of TPE or TPU having a thickness between about 0.2 mm and about 2.0 mm may be used to form a structure having the thickness 1316. In some embodiments, the plurality of projections 1304 may be formed from a 3D textile, also referred to as a spacer fabric. Suitable 3D textiles may be produced by Heathcoat Fabrics, Ltd., Baltex, and Mueller Textil Group. The plurality of projections 1304 can also be formed from polyurethane, silicone, polyvinyl alcohol, and metals, such as copper, tin, silver or other beneficial metals. [00124] In some embodiments, the plurality of projections 1304 may be formed from a foam. For example, cellular foam, open-cell foam, reticulated foam, or porous tissue collections, may be used to form the plurality of projections 1304. In some embodiments, the plurality of projections 1304 may be formed of V.A.C. ^® GRANUFOAM™ Dressing, grey foam, or a type of Zotefoams. Grey foam may be a polyester polyurethane foam having about 60 pores per inch (ppi). Zotefoams may be a closed-cell crosslinked polyolefin foam. In one non-limiting example, the plurality of projections 1304 may be an open-cell, reticulated polyurethane foam such as V.A.C. ^® GRANUFOAM™ Dressing available from Kinetic Concepts, Inc. of San Antonio, Texas; in other embodiments, the plurality of projections 1304 may be an open-cell, reticulated polyurethane foam such as a V.A.C. VERAFLO™ dressing, also available from Kinetic Concepts, Inc., of San Antonio, Texas. In some embodiments, the plurality of projections 1304 may have a 25% compression load deflection of at least 0.35 pounds per square inch, and the 65% compression load deflection may be at least 0.43 pounds per square inch. In some embodiments, the tensile strength of the plurality of projections 1304 may be at least 10 pounds per square inch. The plurality of projections 1304 may have a tear strength of at least 2.5 pounds per inch.

[00125] In some embodiments, the plurality of projections 1304 may be formed from a foam that is mechanically or chemically compressed, often as part of a thermoforming process, to increase the density of the foam at ambient pressure, also known as felting the foam. The compressed foam may be characterized by the firmness factor (FF). Generally a compressed or felted foam may have a firmness factor greater than 1. Mechanically or chemically compressing a foam may reduce a thickness of the foam at ambient pressure when compared to the same foam that has not been compressed. Reducing a thickness of a foam by mechanical or chemical compression may increase a density of the foam, which may increase the firmness factor (FF) of the foam. Increasing the firmness factor (FF) of a foam may increase a stiffness of the foam in a direction that is parallel to a thickness of the foam. For example, increasing a firmness factor (FF) of the plurality of projections 1304 may increase a stiffness of the plurality of projections 1304 in a direction that is parallel to the thickness 1316 of the plurality of projections 1304. In some embodiments, a compressed foam may be a compressed V.A.C. ^® GRANUFOAM™ Dressing. V.A.C. ^® GRANUFOAM™ Dressing may have a density of about 0.03 grams per centimeter³ (g/cm³) in its uncompressed state. If the V.A.C.^® GRANUFOAM™ Dressing is compressed to have a firmness factor (FF) of 5, the V.A.C.^® GRANUFOAM™ Dressing may be compressed until the density of the V.A.C.^® GRANUFOAM™ Dressing is about 0.15g/cm³. V.A.C. VERAFLO™ dressing may also be compressed to form a compressed foam having a firmness factor (FF) up to 5. In some embodiments, the plurality of projections 1304 may have a thickness between about 4 mm and about 15 mm, and more specifically, about 8 mm at ambient pressure. In an exemplary embodiment, if the thickness 1316 of the projections 1304 is about 8 mm, and the plurality of projections 1304 is positioned within the sealed environment and subjected to negative pressure of about -115 mm Hg to about -135 mm Hg, the thickness 1316 of the plurality of projections 1304 may be between about 1 mm and about 5 mm and, generally, greater than about 3 mm.

[00126] Figure 14 is a sectional view of the tissue interface 114 of Figure 13, illustrating additional details that may be associated with some embodiments. As illustrated in Figure 14, the plurality of projections 1304 are coupled to the first surface 1306 of the film layer 1302. Each projection 1304 of the plurality of projections 1304 is substantially uniform and spaced equidistantly from adjacent projections 1304.

[00127] Figure 15 is a sectional view of a portion of the film layer 1302 and the plurality of projections 1304, illustrating additional details that may be associated with some embodiments. The film layer 1302 and the plurality of projections 1304 may be placed at the tissue site 602 having the debris 604 covering the subcutaneous tissue 606. For example, a clinician may place the tissue interface 114 having the film layer 1302 and the plurality of projections 1304 at the tissue site 602 and cover the tissue interface 114 and the tissue site 602 with the cover 116. In some embodiments, the tissue interface 114 may be packaged in a sterile container that the clinician may open and remove. The tissue interface 114 having the film layer 1302 and the plurality of projections 1304 may be removed as a single piece for placement at the tissue site 602. The plurality of projections 1304 may be placed adjacent to and in contact with the debris 604. Following sizing and placement of the tissue interface 114 at the tissue site 602, the cover 116 may be placed over the tissue interface 114 to provide a sealed environment for the application of negative- pressure therapy or instillation therapy. Placement of the tissue interface 114 at the tissue site 602 may create gaps 1502 between the film layer 1302 and the debris 604 and between adjacent projections 1304.

[00128] Figure 16 is a sectional view of a portion of the dressing 104 during negative-pressure therapy, illustrating additional details that may be associated with some embodiments. For example, Figure 16 may illustrate a moment in time where a pressure in the sealed environment may be about -125 mm Hg of negative pressure. In response to the application of negative pressure, the plurality of projections 1304 may not compress or may compress negligibly. In some embodiments, negative pressure in the sealed environment can generate concentrated stresses in the debris 604 adjacent to the gaps 1502. The concentrated stresses can cause macro-deformations of the debris 604 and the subcutaneous tissue 606 that draws portions of the debris 604 and the subcutaneous tissue 606 into gaps 1502. The plurality of projections 1304 may create macro-pressure points in portions of the debris 604 and the subcutaneous tissue 606, causing tissue puckering and the formation of nodules similar to the nodules 802 and the nodules 804 in the debris 604 and the subcutaneous tissue 606 that is adjacent to the gaps 1502.

[00129] As previously described, the height of the nodules over the surrounding tissue may be selected to maximize disruption of debris 604 and minimize damage to subcutaneous tissue 606 or other desired tissue. Controlling the height of the nodules formed by the plurality projections 1304 can be accomplished as described above with respect to the nodules 802 and the nodules 804.

[00130] Figure 17 is a perspective view of another embodiment of the tissue interface 114 of Figure 1 illustrating additional details that may be associated with some embodiments. The tissue interface 114 can include the film layer 1302, the plurality of projections 1304, a plurality of projections 1702, and a cover layer, such as an encapsulating layer 1704. In some embodiments, the plurality of projections 1304 and the plurality of projections 1702 may be encapsulated by the film layer 1302 and the encapsulating layer 1704.

[00131] The plurality of projections 1702 may be a plurality of discrete bodies coupled to the first surface 1306 of the film layer 1302. In some embodiments, each projection 1702 may be a discrete block having a substantially cuboid shape. In other embodiments, each projection 1702 may be spherical, pyramidal, polygonal, or amorphous shaped. Each projection 1702 may have a height 1706, a width 1708, and a thickness 1710. In some embodiments, the height 1706, the width 1708, and the thickness 1710 may be substantially uniform between projections 1702. In other embodiments, the height 1706, the width 1708, and the thickness 1710 of the plurality of projections 1702 may vary. In some embodiments, each of the height 1706, the width 1708, and the thickness 1710 may be between about 0.5 mm and about 3 mm. In other embodiments, the height 1706, the width 1708, and the thickness 1710 may be thinner or thicker than the stated range as needed for the particular application of the dressing 104. In some embodiments, individual portions of the plurality of projections 1702 may have a minimal tolerance from each of the height 1706, the width 1708, and the thickness 1710. In some embodiments, each of the height 1706, the width 1708, and the thickness 1710 may have a tolerance of about 2 mm. In some embodiments, each of the height 1706, the width 1708, and the thickness 1710 may be between about 0.5 mm and about 3 mm. The plurality of projections 1702 may be flexible so that the plurality of projections 1702 can be contoured to a surface of the tissue site.

[00132] The projections 1702 can be coupled to the film layer 1302 by welding, adhering, bonding, mechanical fixation, or other suitable means of securing the projections 1702 to the film layer 1302. In some embodiments, the projections 1702 may be disposed on the film layer 1302 with a regular pitch. For example, the projections 1702 may have a pitch 1712 in a first direction, and a pitch 1714 in a second direction perpendicular to the pitch 1712. In some embodiments, the pitch 1712 and the pitch 1714 may be between 10 mm and about 500 mm. In other embodiments, the pitch 1712 and the pitch 1714 may not be perpendicular to each other and can be at a non-perpendicular angle to an edge of the film layer 1302. In some embodiments, the projections 1702 can have an arcuate pitch 1712 disposing the projections 1702 circumferentially about a point on the film layer 1302. Where the pitch 1712 is arcuate, the projections 1702 can have a radial pitch 1714 disposing the projections 1702 radially outward from the point on the film layer 1302.

[00133] In some embodiments, the projections 1304 and the projections 1702 may be spaced from each other with a regular pitch. For example, the projections 1304 and the projections 1702 may have a pitch 1716 in a first direction parallel to the pitch 1712, and a pitch 1718 in a second direction perpendicular to the pitch 1716 and parallel to the pitch 1714. In some embodiments, the pitch 1716 and the pitch 1718 may be between 10 mm and about 500 mm and consistent with the pitch 1318, the pitch 1320, the pitch 1712, and the pitch 1714.

[00134] In some embodiments, the plurality of projections 1702 maybe formed a material similar to the material of the plurality of projections 1304. In some embodiments, each of the plurality of projections 1702 can be formed from a foam similar to the foam of the plurality of projections 1304 and having a higher felting or firmness factor. In some embodiments, each of the projections 1702 may be felted about 3 to about 5 times the foam of the projections 1304.

[00135] The encapsulating layer 1704 may have a first surface 1722 and a second surface 1724. In some embodiments, the encapsulating layer 1704 may comprise or consist essentially of a means for controlling or managing fluid flow. In some embodiments, the encapsulating layer 1704 may comprise or consist essentially of an elastomeric material that is impermeable to liquid. For example, the encapsulating layer 1704 may comprise or consist essentially of a polymer film similar to the film layer 1302. As illustrated in the example of Figure 17, the encapsulating layer 1704 may have one or more fluid restrictions 1720, which may be similar to the fluid restrictions 1310 and can be distributed uniformly or randomly across the encapsulating layer 1704. The fluid restrictions 1720 may be bi-directional and pressure- responsive. For example, each of the fluid restrictions 1720 generally may comprise or consist essentially of an elastic passage that is normally unstrained to substantially reduce liquid flow, and can expand or open in response to a pressure gradient.

[00136] Figure 18 is a sectional view of the tissue interface 114 of Figure 17, illustrating additional details that may be associated with some embodiments. As illustrated in Figure 18, the plurality of projections 1304 and the plurality of projections 1702 are coupled to the first surface 1306 of the film layer 1302. A first surface 1722 of the encapsulating layer 1704 can be positioned over the plurality of projections 1304 and the plurality of projections 1702 and coupled to the first surface 1306 of the film layer 1302 to encapsulate the plurality of projections 1304 and the plurality of projections 1702. In some embodiments, the encapsulating layer 1704 can be welded, for example by radio-frequency welding, adhered, such as by use of an adhesive or lamination, or otherwise secured to the film layer 1302.

[00137] Figure 19 is a perspective view of another embodiment of the tissue interface 114 of Figure 1 illustrating additional details that may be associated with some embodiments. The tissue interface 114 can include the film layer 1302, the plurality of projections 1304, and the encapsulating layer 1704. In some embodiments, the plurality of projections 1304 may be coupled to the film layer 1302. The plurality of projections 1304 may be a plurality of discrete bodies coupled to the first surface 1306 of the film layer 1302. In some embodiments, the height 1312 of each projection 1304 may be substantially greater than the width 1314 and the thickness 1316. For example, the height 1312 of each projection may be a length of the film layer 1302 so that each projection 1304 extends across the film layer 1302 to form channels 1902 between adjacent projections 1304. In a preferred embodiment, the height 1312, may be between about 0.5 mm and about 10 mm, and the width 1314 and the thickness 1316 may be about 0.5 mm and about 10 mm. The plurality of projections 1304 can have the pitch 1318 in the first direction perpendicular to the height 1312. The plurality of projections 1304 can form a plurality of channels 1902. For example, the pitch 1318 spaces adjacent projections 1304 from each other. The gap between adjacent projections 1304 forms the channel 1902 parallel to the height 1312.

[00138] Figure 20 is a perspective view of another embodiment of the tissue interface 114 of Figure 1 illustrating additional details that may be associated with some embodiments. The tissue interface 114 can include the film layer 1302, the plurality of projections 1304, and the plurality of projections 1702.

[00139] The plurality of projections 1304 may be a plurality of discrete bodies coupled to the first surface 1306 of the film layer 1302. In some embodiments, the height 1312 of each projection 1304 may be substantially greater than the width 1314 and the thickness 1316. For example, the height 1312 of each projection may be a length of the film layer 1302 so that each projection 1304 extends across the film layer 1302 to form the channels 1902 between adjacent projections 1304. Similarly, the plurality of projections 1702 may be a plurality of discrete bodies coupled to the first surface 1306 of the film layer 1302. In some embodiments, the height 1706 of each projection 1702 may be substantially greater than the width 1708 and the thickness 1710. For example, the height 1706 of each projection 1702 may be a length of the film layer 1302 so that each projection 1702 extends across the film layer 1302. In some embodiments, each projection 1702 can be disposed in a channel 1902 between adjacent projections 1304. In some embodiments, the projections 1304 and the projections 1702 are equidistantly spaced across the film layer 1302. In other embodiments, the projections 1304 and the projections 1702 can be positioned to increase tissue deformation in preferred areas.

[00140] The systems, apparatuses, and methods described herein may provide significant advantages. For example, in some embodiments, the tissue interface 114 can provide wound bed preparation while also inducing granulation tissue formation. The tissue interface 114 can soften devitalized tissue, increasing the ease of devitalized tissue removal and permitting the granulation phase of healing to begin. The tissue interface 114 can stimulate the tissue site so that the tissue site has a normal healing trajectory. The tissue interface 114 can have a variety of geometries to create strain and deformation in the tissue site. The tissue interface 114 can aid in the removal of thick exudate and larger debris from the tissue site and the dressing 104. The tissue interface 114 can induce robust granulation tissue induction and re-epithelialization whilst mitigating ingrowth of tissue into the tissue interface 114. The tissue interface 114 can also aid in the vital process of removing devitalized tissue, microbes, and slough that is crucial in stimulating the wound towards a normal healing trajectory.

[00141] 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 102, the container 112, or both may be eliminated or separated from other components for manufacture or sale. In other example configurations, the controller 108 may also be manufactured, configured, assembled, or sold independently of other components.

[00142] 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.

[00143] In some embodiments, excising separable sections may comprise cutting a seam or a seal between the separable sections. In some configurations, the separable sections may be excised without exposing a manifold section inside the dressing.

[00144] In some embodiments, applying negative pressure from the negative-pressure source to the dressing can include drawing tissue into the openings of the tissue interface. The method may rupture or otherwise disrupt the tissue drawn into the openings, aiding in the removal of necrotic tissue or slough.

Claims

CLAIMS What is claimed is:

1. A dressing for treating a tissue site, the dressing comprising: a foam having a foam thickness from a first side of the foam to a second side of the foam; a plurality of holes extending through the foam from the first side to the second side; a film having a film thickness and a plurality of perforations extending through the film; a plurality of welds coupling the film to the first side of the foam, each of the plurality of welds being separated from the plurality of holes.

2. The dressing of claim 1, wherein the foam is felted.

3. The dressing of claim 1 or claim 2, wherein the foam thickness is uniform.

4. The dressing of claim 1, wherein the foam thickness is between about 5 mm to about 30 mm.

5. The dressing of claim 1, wherein the foam thickness is a first thickness, the foam further comprising a second thickness that is different than the first thickness.

6. The dressing of claim 5, wherein the first thickness and the second thickness are between about 5 mm and about 30 mm.

7. The dressing of any of claims 1-6, where the film thickness is between about 25 microns and about 200 microns.

8. The dressing of any of claims 1-7, wherein the film is formed from polyurethane.

9. The dressing of any of claims 1-7, wherein the film is formed from polyethylene.

10. The dressing of any of claims 1-7, wherein the film is formed from polypropylene.

11. The dressing of any of claims 1-7, wherein the film is formed from polyvinyl chloride.

12. The dressing of any of claims 1-7, wherein the film is formed from cellophase.

13. The dressing of any of claims 1-7, wherein the film is formed from cellulose.

14. The dressing of any of claims 1-7, wherein the film is formed from acetate.

15. The dressing of claim 1, wherein the welds comprise RF welds.

16. The dressing of claim 1, wherein the welds comprise adhesive welds.

17. The dressing of claim 1, wherein the welds comprise localized heat welds.

18. The dressing of claim 1, wherein the plurality of welds comprise a continuous weld.

19. The dressing of claim 1, wherein the plurality of welds comprise discrete welds.

20. The dressing of claim 19, wherein each weld has a length between about 2 mm and about 15 mm.

21. The dressing of any of claims 15-20, further comprising a plurality of weld slits disposed in the welds.

22. The dressing of claim 21, wherein each weld slit of the plurality of weld slits has a length between about 2 mm and about 3 mm.

23. The dressing of any of claims 1-22, wherein the plurality of perforations comprise a plurality of slits.

24. The dressing of claim 23, wherein each slit of the plurality of slits has a length between about 2 mm and about 5 mm.

25. The dressing of any of claims 1-23, wherein the plurality of perforations are circular.

26. The dressing of any of claims 1-23, wherein the plurality of perforations are elliptical.

27. The dressing of any of claims 1-23, wherein the plurality of perforations are polygonal.

28. The dressing of any of claims 25-27, wherein each perforation has an average effective diameter between about 0.5 mm and about 5 mm.

29. The dressing of claim 1, wherein the foam further comprises: a plurality of raised portions surrounding the plurality of holes; and a plurality of depending portions coincident with the plurality of welds.

30. The dressing of claim 29, wherein the raised portions comprise linear shapes.

31. The dressing of claim 29, wherein the raised portions comprise circular shapes.

32. The dressing of claim 29, wherein the raised portions comprise elliptical shapes.

33. The dressing of claim 29, wherein the raised portions comprise polygonal shapes.

34. The dressing of any of claims 29-33, wherein the raised portions are filled.

35. The dressing of any of claims 29-33, wherein the raised portions comprise outlines.

36. The dressing of any of claims 29-35, wherein the raised portions are uniform.

37. The dressing of any of claims 29-35, wherein the raised portions are non-uniform.

38. The dressing of any of claims 29-35, wherein each raised portion has at least one hole of the plurality of holes.

39. The dressing of claim 38, wherein each raised portion has more than one hole.

40. The dressing of any of claims 1-39, further comprising a plurality of fenestrations defining a pattern, portions of the foam and the film being separable from adjacent portions of the foam and the film along the pattern.

41. The dressing of any of claims 1-40, wherein the film is impregnated with an antimicrobial compound.

42. The dressing of claim 41, wherein the antimicrobial compound comprises 1% to 5% chlorhexidine.

43. The dressing of claim 41, wherein the antimicrobial compound comprises 0.2% to 5% silver.

44. The dressing of claim 41, wherein the antimicrobial compound comprises 0.2% to 5% gold

45. The dressing of claim 41, wherein the antimicrobial compound comprises 0.2% to 5% copper.

46. The dressing of claim 41, wherein the antimicrobial compound comprises 0.2% to 5% palladium.

47. The dressing of claim 1, wherein the film is a first film, the plurality of welds are a first plurality of welds, and the dressing further comprises: a second film having a second film thickness and a second plurality of perforations extending through the second film; and a second plurality of welds coupling the film to the second side of the foam, each of the second plurality of welds being separated from the plurality of holes.

48. The dressing of claim 47, wherein the first film and the second film encapsulate the foam.

49. The dressing of claim 47, wherein the first plurality of welds and the second plurality of welds are coincident.

50. A dressing for treating a tissue site, the dressing comprising: a contact layer having a plurality of perforations extending through the contact layer; and a plurality of tissue disruption members coupled to the contact layer, the tissue disruption members being spaced apart from each other.

51. The dressing of claim 50, wherein the plurality of tissue disruption members comprise discrete blocks.

52. The dressing of claim 51, wherein the discrete blocks are cubes.

53. The dressing of claim 51, wherein the discrete blocks are polygonal.

54. The dressing of claim 51, wherein the discrete blocks are amorphous.

55. The dressing of claim 51, wherein the discrete blocks comprise: a first plurality of discrete blocks having a first major dimension; a second plurality of discrete blocks having a second major dimension; and the first major dimension is different than the second major dimension.

56. The dressing of claim 50, wherein the plurality of tissue disruption members comprises a plurality of parallel rows.

57. The dressing of claim 56, wherein the parallel rows comprise: a first plurality of parallel rows having a first height; a second plurality of parallel rows having a second height; and the first height is different than the second height.

58. The dressing of claim 50, wherein the tissue disruption members are formed from a foam.

59. The dressing of claim 50, wherein the tissue disruption members are formed from felted foam.

60. The dressing of claim 50, further comprising a cover layer having a plurality of perforations extending through the cover layer and positioned over the plurality of tissue disruption members, the cover layer being coupled to the contact layer.

61. A method for treating a tissue site with negative-pressure, the method comprising: providing a dressing for treating the tissue site having: a foam having a foam thickness from a first side of the foam to a second side of the foam; a plurality of holes extending through the foam from the first side to the second side; a film having a film thickness and a plurality of perforations extending through the film; a plurality of welds coupling the film to the first side of the foam, each of the plurality of welds being separated from the plurality of holes; positioning the dressing adjacent to the tissue site; fluidly coupling a negative-pressure source to the dressing; applying negative pressure to the dressing with the negative-pressure source; and drawing a portion of the film and the tissue site into the plurality of holes.

62. A method for treating a tissue site with negative-pressure, the method comprising: providing a dressing for treating the tissue site having: a contact layer having a plurality of perforations extending through the contact layer; and a plurality of tissue disruption members coupled to the contact layer, the tissue disruption members being spaced apart from each other to create free areas between the tissue disruption members; positioning the dressing adjacent to the tissue site; fluidly coupling a negative-pressure source to the dressing; applying negative pressure to the dressing with the negative-pressure source; and drawing a portion of the contact layer and the tissue site into the free areas.

63. The systems, apparatuses, and methods substantially as described above.