Negative pressure wound therapy dressings including in vivo optical sensing

Abstract

A dressing for treating a tissue site with negative pressure includes a cover, a wound contact layer, a manifold, and at least one sensor. The cover includes a first surface and a second surface. The wound contact layer includes a first surface and a second surface, wherein the second surface of the wound contact layer is configured to contact the tissue site. The manifold includes a first surface and a second surface. The manifold is configured to be disposed between the second surface of the cover and the first surface of the wound contact layer. The at least one sensor may include a plurality of oxygen sensing molecules dissolved in a polymer matrix. The at least one sensor is configured to change color to indicate a sensed oxygen level when the at least one sensor is acted on by the light source.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 351,029, filed on June 10, 2022, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention as set forth in the appended claims relates generally to tissue treatment systems and more particularly (but not exclusively) to negative pressure wound therapy dressings including in vivo optical sensors. Background Art

[0004] Clinical studies and practice have shown that reducing the pressure near a tissue site can increase and accelerate the growth of new tissue at the tissue site. The application of this phenomenon is many, but it has been proven to be particularly beneficial for treating wounds. Regardless of the cause of the wound (whether it is trauma, surgery or other reasons), proper care of the wound is important for the result. Treating wounds or other tissues with reduced pressure is generally referred to as "negative pressure therapy", but is also referred to as other names, including, for example, "negative pressure wound therapy", "reduced pressure therapy", "vacuum therapy", "vacuum assisted closure" and "local negative pressure". Negative pressure therapy can provide many benefits, including migration of epithelial tissue and subcutaneous tissue, improvement of blood flow and micro-deformation of tissue at the wound site. In short, these benefits can increase the development of granulation tissue and reduce healing time.

[0005] It is also generally accepted that cleaning tissue sites can be highly beneficial for new tissue growth. For example, for therapeutic purposes, a wound or cavity can be flushed with a liquid solution. These practices are generally referred to as "flushing" and "irrigation", respectively. "Instillation" is another practice, which generally refers to the process of slowly introducing a fluid into a tissue site and retaining the fluid for a specified period of time before removing the fluid. For example, instillation of a topical treatment solution over a wound bed can be combined with negative pressure therapy to further promote wound healing by loosening soluble contaminants in the wound bed and removing infectious materials. Thus, the soluble bacterial burden can be reduced, contaminants can be removed, and the wound can be cleaned.

[0006] While the clinical benefits of negative pressure therapy and / or infusion therapy are well known, improvements to therapy systems, components, and processes may benefit healthcare providers and patients. Summary of the invention

[0007] New and useful systems, devices and methods for sensing changes at or near a wound site in a negative pressure therapy environment are set forth in the appended claims. Exemplary embodiments are also provided to enable one skilled in the art to make and use the claimed subject matter.

[0008] For example, in some embodiments, a dressing for treating a tissue site using negative pressure is described. The dressing may include a cover, a wound contact layer including at least one sensor, a first film layer, and a manifold. The cover may include a first surface and a second surface. The wound contact layer may include a first surface, a second surface, and a central hole. The second surface of the wound contact layer may be configured to contact a peri-wound area of ​​the tissue site. The first film layer may include a first surface and a second surface. The second surface of the first film layer may be configured to contact a wound at the tissue site. The manifold may include a first surface and a second surface. The manifold may be configured to be disposed between the second surface of the cover and the first surface of the first film layer. At least one sensor may include a plurality of oxygen sensing molecules dissolved in a polymer matrix. At least one sensor may be configured to change color to indicate a sensed oxygen level when the at least one sensor is acted upon by a light source.

[0009] In some exemplary embodiments, the wound contact layer may further include a peripheral portion surrounding the central portion. The peripheral portion may include a plurality of holes. In some exemplary embodiments, at least one sensor may be disposed within one of the plurality of holes in the wound contact layer. In other exemplary embodiments, at least one sensor may be disposed between the first surface of the wound contact layer and the second surface of the cover. At least one sensor may be offset from the plurality of holes in the wound contact layer.

[0010] In some exemplary embodiments, at least one sensor may include an oxygen sensing membrane. In some exemplary embodiments, the oxygen sensing membrane may include a low oxygen permeability polymer or a high oxygen permeability polymer. In some exemplary embodiments, the low oxygen permeability polymer may include one of polyvinyl alcohol, ethylene vinyl alcohol, polyacrylonitrile, and polyvinylidene chloride. In some exemplary embodiments, the high oxygen permeability polymer may include one of silicone and a polyolefin elastomer.

[0011] In some exemplary embodiments, the at least one sensor may include a multi-sensor configured to detect fluid level, oxygen level, and pH level.

[0012] Another dressing for treating a tissue site using negative pressure is also described herein. The dressing may include a cover having at least one sensor, a wound contact layer, a first film layer, and a manifold. The cover may include a first surface and a second surface. The wound contact layer may include a first surface, a second surface, and a central hole. The second surface of the wound contact layer may be configured to contact a peri-wound area of ​​a tissue site. The first film layer may include a first surface and a second surface. The second surface of the first film layer may be configured to contact a wound at a tissue site. The manifold may include a first surface and a second surface. The manifold may be configured to be disposed between the second surface of the cover and the first surface of the first film layer. At least one sensor may include a plurality of oxygen sensing molecules dissolved in a polymer matrix. At least one sensor may be configured to change color to indicate a sensed oxygen level when the at least one sensor is acted upon by a light source.

[0013] In other exemplary embodiments, the at least one sensor may be disposed within a recess in the first surface of the cover such that the at least one sensor is aligned with one of the plurality of holes in the wound contact layer. In some exemplary embodiments, the dressing may further include a recess cover removably coupled to the first surface of the cover. The recess cover may be configured to seal the at least one sensor within the recess in the first surface of the cover. In other exemplary embodiments, the at least one sensor may be disposed on the first surface of the cover such that the sensor is aligned with one of the plurality of holes in the wound contact layer.

[0014] In some exemplary embodiments, the cover may further include a central portion having a central hole and a peripheral portion. The peripheral portion of the cover may be configured to be coupled to the peripheral portion of the wound contact layer. In some exemplary embodiments, the cover may further include a second film layer having a first surface and a second surface. The second film layer may be configured to be substantially aligned with the central hole of the cover, and the second surface of the second film layer may be coupled to the first surface of the manifold. In some exemplary embodiments, at least one sensor may be disposed in a recess in the first surface of the second film layer. In some exemplary embodiments, the dressing may further include a recess cover that is removably coupled to the first surface of the second film layer. The recess cover may be configured to seal at least one sensor in a recess in the first surface of the second film layer. In some embodiments, at least one sensor may be disposed between the first surface of the manifold and the second surface of the second film layer. In other embodiments, the dressing may further include at least one sealed cavity between the first surface of the manifold and the second surface of the second film layer. At least one sensor may be disposed in at least one sealed cavity.

[0015] Another dressing for treating a tissue site using negative pressure is also described herein. The dressing may include a cover, a wound contact layer, a first film layer, a manifold, and at least one sensor. The cover may include a first surface and a second surface. The wound contact layer may include a first surface, a second surface, and a central hole. The second surface of the wound contact layer may be configured to contact a periwound area of ​​a tissue site. The first film layer may include a first surface and a second surface. The second surface of the first film layer may be configured to contact a wound at a tissue site. The manifold may include a first surface and a second surface. The manifold may be configured to be disposed between the second surface of the cover and the first surface of the first film layer. At least one sensor may be recessed in the second surface of the first film layer. At least one sensor may include a plurality of oxygen sensing molecules dissolved in a polymer matrix. At least one sensor may be configured to change color to indicate a sensed oxygen level when the at least one sensor is acted upon by a light source.

[0016] Another dressing for treating a tissue site using negative pressure is also described herein. The dressing may include a cover, a wound contact layer, a first film layer, a manifold, and at least one sensor. The cover may include a first surface and a second surface. The wound contact layer may include a first surface, a second surface, and a central hole. The second surface of the wound contact layer may be configured to contact a periwound area of ​​a tissue site. The first film layer may include a first surface and a second surface. The second surface of the first film layer may be configured to contact a wound at a tissue site. The manifold may include a first surface and a second surface. The manifold may be configured to be disposed between the second surface of the cover and the first surface of the first film layer. At least one sensor may be disposed between the second surface of the manifold and the first surface of the first film layer. At least one sensor may include a plurality of oxygen sensing molecules dissolved in a polymer matrix. At least one sensor may be configured to change color to indicate a sensed oxygen level when the at least one sensor is acted upon by a light source.

[0017] In some exemplary embodiments, at least one sensor may be disposed proximate to a window of the manifold such that the at least one sensor is visible through the window of the manifold.

[0018] Also described herein is a method for treating a tissue site using negative pressure. The method may include placing a dressing on a tissue site, applying negative pressure to the dressing from a negative pressure source, and monitoring changes in a sensed parameter of the dressing at the tissue site. The dressing may include a cover, a wound contact layer, a manifold, and at least one sensor. The cover may include a first surface and a second surface. The wound contact layer may include a first surface and a second surface. The second surface of the wound contact layer may be configured to contact the tissue site. The manifold may include a first surface and a second surface. The manifold may be configured to be disposed between the second surface of the cover and the first surface of the wound contact layer. At least one sensor may include a plurality of parameter sensing molecules dissolved in a polymer matrix. At least one sensor may be configured to indicate a sensed parameter when the at least one sensor is acted upon by a light source.

[0019] In some exemplary embodiments, monitoring the dressing for changes in a sensed parameter at a tissue site may include detecting a color change in the at least one sensor when the at least one sensor is acted upon by a light source.

[0020] In some exemplary embodiments, the sensed parameter may include at least one of fluid level, oxygen level, and pH.

[0021] Also described herein is a wound contact layer for treating a tissue site. The wound contact layer may include a central portion, a peripheral portion, and at least one sensor. In some exemplary embodiments, the peripheral portion may surround the central portion. In some exemplary embodiments, the peripheral portion may include a plurality of holes. In some exemplary embodiments, at least one sensor may include a plurality of oxygen sensing molecules dissolved in a polymer matrix. At least one sensor may be integrated into the peripheral portion separately from each of the plurality of holes. In some exemplary embodiments, at least one sensor may be configured to change color to indicate a sensed oxygen level when the at least one sensor is acted upon by a light source.

[0022] The objects, advantages and preferred modes of making and using the claimed subject matter may be best understood by referring to the accompanying drawings in conjunction with the following detailed description of illustrative embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a block diagram of an exemplary embodiment of a therapy system that can provide negative pressure therapy and infusion therapy according to the present specification;

[0024] Figure 2 yes Figure 1 An exploded view of an example of a dressing illustrating additional details that may be associated with some embodiments;

[0025] Figure 3 yes Figure 2 A perspective view of the dressing after assembly;

[0026] Figure 4 yes Figure 3 A cross-sectional view of a dressing taken along line 4-4 applied to an exemplary tissue site and illustrating Figure 1 Additional details associated with some examples of treatment systems;

[0027] Figure 5A yes Figure 1 A perspective view of another example of a dressing illustrating additional details that may be associated with some embodiments;

[0028] Figure 5B yes Figure 5A A perspective view of a dressing including a sensor cover that may be associated with some exemplary embodiments;

[0029] Figure 5C yes Figure 5B A cross-sectional view of the dressing taken along line 5C-5C;

[0030] Figure 5D yes Figure 5B A cross-sectional view of the dressing taken along line 5D-5D;

[0031] Fig. 6A Is set in Figure 1 A cross-sectional view of a sensor within a wound contact layer of a dressing;

[0032] Figure 6B is integrated into Figure 1 A cross-sectional view of a sensor in a wound contact layer of a dressing;

[0033] Figure 6C Is set in Figure 1 A cross-sectional view of a sensor between a wound contact layer and a cover of a dressing;

[0034] Fig.6D Is set in Figure 1 a cross-sectional view of a sensor at another location between the wound contact layer and the cover of a dressing;

[0035] Fig. 6E Is set in Figure 1 a cross-sectional view of a sensor within a recess of a covering member of a dressing;

[0036] Fig. 6F is with Figure 1 A cross-sectional view of a sensor disposed on a cover relative to a wound contact layer of a dressing;

[0037] Fig. 7A is with Figure 1 A cross-sectional view of a sensor disposed on a wound contact layer relative to a manifold of a dressing;

[0038] Figure 7B Is set in Figure 1 A cross-sectional view of a sensor between a manifold and a wound contact layer of a dressing;

[0039] Figure 7C Is set in Figure 1 A cross-sectional view of a sensor between a manifold and a cover of a dressing;

[0040] Fig.7D Is set in Figure 1 a cross-sectional view of a sensor at another location between a manifold and a cover of a dressing;

[0041] Fig. 7E Is set in Figure 1 A cross-sectional view of a sensor within a sealed cavity between a manifold and a cover of a dressing;

[0042] Figure 7F is with Figure 1 A cross-sectional view of a sensor disposed on a cover relative to a manifold of a dressing;

[0043] Fig. 8A Is set in Figure 1 a cross-sectional view of a sensor within a recess of a covering member of a dressing;

[0044] Figure 8B Is set in Figure 1 a cross-sectional view of a sensor within another recess of a covering member of a dressing;

[0045] Fig. 9 It is available with Figure 1 A side view of a multi-sensor for use with a dressing; and

[0046] Fig.10 Deployed in tissues Figure 5A A perspective view of the dressing being acted upon by a light source. DETAILED DESCRIPTION

[0047] The following description of exemplary embodiments provides information enabling those skilled in the art to make and use the subject matter set forth in the appended claims, but may omit certain details already known in the art. Therefore, the following detailed description is to be regarded as illustrative rather than limiting.

[0048] Figure 1 is a block diagram of an exemplary embodiment of a treatment system 100 that can provide negative pressure therapy as well as instillation of a localized therapeutic solution to a tissue site in accordance with the present specification.

[0049] In this article, the term "tissue site" refers broadly to a wound, defect or other treatment target located on or in a tissue, including but not limited to bone tissue, adipose tissue, muscle tissue, nerve tissue, skin tissue, vascular tissue, connective tissue, cartilage, tendon or ligament. Wounds may include, for example, chronic wounds, acute wounds, traumatic wounds, subacute wounds and dehiscence wounds, partial thickness burns, ulcers (such as diabetic ulcers, pressure sores or venous insufficiency ulcers), flaps and grafts. The term "tissue site" may also refer to an area of ​​any tissue that is not necessarily injured or defective, but rather an area in which it may be desirable to add additional tissue or promote the growth of additional tissue. For example, negative pressure may be applied to a tissue site to allow additional tissue to grow, and then the additional tissue may be removed and transplanted.

[0050] The treatment system 100 may include a negative pressure source or negative pressure supply device (such as negative pressure source 105) and one or more dispensing components. The dispensing components are preferably detachable and can be disposable, reusable, or recyclable. Dressings (such as dressing 110) and fluid containers (such as container 115) are examples of dispensing components that may be associated with some examples of the treatment system 100. Figure 1 As illustrated in the example of , in some embodiments, the dressing 110 can include or consist essentially of a tissue interface 120, a cover 125, or both.

[0051] A fluid conductor is another illustrative example of a distribution component. In this article, a "fluid conductor" broadly includes a tube, a pipe or hose, a catheter, or other structure having one or more lumens or open passages suitable for conveying fluid between two ends. Typically, the tube is an elongated cylindrical structure with a certain flexibility, but the geometry and rigidity can vary. In addition, some fluid conductors can be molded into other components or otherwise integrally combined with other components. The distribution component may also include or include an interface or fluid port to facilitate the connection and separation of other components. In some embodiments, for example, a dressing interface can facilitate the connection of the fluid conductor to the dressing 110. For example, such a dressing interface can be a SENSAT.RAC available from Kinetic Concepts, Inc., San Antonio, Texas. TM pad.

[0052] The treatment system 100 may also include a regulator or controller, such as controller 130. Additionally, the treatment system 100 may include sensors to measure operating parameters and provide feedback signals indicative of the operating parameters to the controller 130. Figure 1 As illustrated, for example, treatment system 100 may include a first sensor 135 and a second sensor 140 coupled to controller 130 .

[0053] The treatment system 100 may also include an instillation solution source. For example, the solution source 145 may be fluidly coupled to the dressing 110, such as Figure 1 As illustrated in the exemplary embodiment of . In some embodiments, the solution source 145 may be fluidly connected to a positive pressure source (such as positive pressure source 150), a negative pressure source (such as negative pressure source 105), or both. A regulator (such as a drip regulator 155) may also be fluidly connected to the solution source 145 and the dressing 110 to ensure that an appropriate dose of infusion solution (e.g., saline) is delivered to the tissue site. For example, the drip regulator 155 may include a piston that can be pneumatically actuated by the negative pressure source 105 to draw the infusion solution from the solution source during the negative pressure interval and drip the solution into the dressing during the ventilation interval. Additionally or alternatively, the controller 130 may be connected to the negative pressure source 105, the positive pressure source 150, or both to control the dose of the infusion solution to the tissue site. In some embodiments, the drip regulator 155 may also be fluidly connected to the negative pressure source 105 through the dressing 110, such as Figure 1 exemplified in the example.

[0054] Some components of the treatment 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 treatment. For example, in some embodiments, the negative pressure source 105 may be combined with the controller 130, the solution source 145, and other components into a treatment unit 160.

[0055] In general, the components of the treatment system 100 may be coupled directly or indirectly. For example, the negative pressure source 105 may be directly coupled to the container 115 and may be indirectly coupled to the dressing 110 through the container 115. The coupling may include a fluid coupling, a mechanical coupling, a thermal coupling, an electrical coupling, or a chemical coupling (such as a chemical bond), or in some cases some combination of couplings. For example, the negative pressure source 105 may be electrically coupled to the controller 130 and may be fluidly coupled to one or more distribution components to provide a fluid path to the tissue site. In some embodiments, the components may also be coupled by means of physical proximity, integration into a single structure, or formation from the same piece of material.

[0056] Negative pressure supply device (such as negative pressure source 105) can be a reservoir of air at negative pressure, or can be a manual or electric device, such as a vacuum pump, a suction pump, a wall suction port or a micro pump available at many healthcare facilities. "Negative pressure" generally refers to a pressure less than the local environmental pressure, such as the ambient pressure in the local environment outside the sealed treatment environment. In many cases, the local environmental pressure can also be the atmospheric pressure where the tissue site is located. Alternatively, the pressure can be less than the hydrostatic pressure associated with the tissue at the tissue site. Unless otherwise specified, the values ​​of the pressures stated herein are gauge pressures. Mentioning an increase in negative pressure generally refers to a decrease in absolute pressure, while a decrease in negative pressure generally refers to an increase in absolute pressure. Although the amount and nature of the negative pressure provided by the negative pressure source 105 can vary according to treatment requirements, the pressure is generally a low vacuum between -5mm Hg (-667Pa) and -500mm Hg (-66.7kPa), which is also generally referred to as a rough vacuum. The common treatment range is between -50 mm Hg (-6.7 kPa) and -300 mm Hg (-39.9 kPa).

[0057] Container 115 represents a container, canister, pouch, or other storage component that can be used to manage exudate and other fluids drawn 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 reusable containers may reduce waste and costs associated with negative pressure therapy.

[0058] A controller, such as controller 130, may be a microprocessor or computer programmed to operate one or more components of treatment system 100, such as negative pressure source 105. In some embodiments, for example, controller 130 may be a microcontroller, which typically includes an integrated circuit containing a processor core and a memory programmed to directly or indirectly control one or more operating parameters of treatment system 100. For example, the operating parameters may include the power applied to negative pressure source 105, the pressure generated by negative pressure source 105, or the pressure distributed to tissue interface 120. Controller 130 is also preferably configured to receive one or more input signals, such as feedback signals, and is programmed to modify one or more operating parameters based on the input signals.

[0059] Sensors (such as, first sensor 135 and second sensor 140) can be devices operable to detect or measure physical phenomena or characteristics, and generally provide signals indicating the detected or measured phenomena or characteristics. For example, the first sensor 135 and the second sensor 140 can be configured to measure one or more operating parameters of the treatment system 100. In some embodiments, the first sensor 135 can be a transducer configured to measure the pressure in the pneumatic passage and convert the measurement result into a signal indicating the measured pressure. In some embodiments, for example, the first sensor 135 can be a piezoresistive strain gauge. In some embodiments, the second sensor 140 can optionally measure an operating parameter of the negative pressure source 105, such as voltage or current. Preferably, the signals from the first sensor 135 and the second sensor 140 are suitable as input signals to the controller 130, but in some embodiments, some signal conditioning can be appropriately performed. For example, before the signal can be processed by the controller 130, it may be necessary to filter or amplify the signal. Typically, the signal is an electrical signal, but can be represented in other forms, such as an optical signal.

[0060] The tissue interface 120 may generally be adapted to partially or completely contact a tissue site. The tissue interface 120 may take a variety of forms and may have a variety of sizes, shapes, or thicknesses, depending on various factors, such as the type of treatment being performed or the nature and size of the tissue site. For example, the size and shape of the tissue interface 120 may be adapted to the contours of a deeper and irregularly shaped tissue site. Any or all surfaces of the tissue interface 120 may have an uneven, rough, or jagged profile.

[0061] In some embodiments, the tissue interface 120 may include or consist essentially of a manifold. The manifold herein may include or consist essentially of a device for collecting or distributing fluid across the tissue interface 120 under pressure. For example, the manifold may be adapted to receive negative pressure from a source and distribute the negative pressure across the tissue interface 120 through a plurality of holes, which may have the effect of collecting fluid from the entire tissue site and drawing the fluid toward the source. In some embodiments, the fluid path may be reversed or may be provided to facilitate a secondary fluid path for delivering fluid (such as fluid from an instillation solution source) to the tissue site.

[0062] In some exemplary embodiments, the manifold may include a plurality of passages that may be interconnected to improve the distribution or collection of fluids. In some exemplary embodiments, the manifold may include or be substantially composed of a porous material having interconnected fluid passages. Examples of suitable porous materials that may be suitable for forming interconnected fluid passages (e.g., channels) may include: porous foams, including open-cell foams, such as reticulated foams; porous tissue collections; and other porous materials that typically include pores, edges, and / or walls, such as gauze or felt pads. Liquids, gels, and other foams may also include or be cured to include pores and fluid passages. In some embodiments, the manifold may additionally or alternatively include projections that form interconnected fluid passages. For example, the manifold may be molded to provide surface projections that define interconnected fluid passages.

[0063] In some embodiments, the tissue interface 120 may include or consist essentially of a reticulated foam having a pore size and free volume that may vary according to the needs of the prescribed treatment. For example, a reticulated foam having at least 90% free volume may be suitable for many therapeutic applications, and a foam having an average pore size in the range of 400 microns to 600 microns (40 to 50 pores / inch) may be particularly suitable for some types of treatment. The tensile strength of the tissue interface 120 may also vary according to the needs of the prescribed treatment. For example, for the instillation of a local therapeutic solution, the tensile strength of the foam may be increased. The 25% compressive load deflection of the tissue interface 120 may be at least 0.35 pounds per square inch, and the 65% compressive load deflection may be at least 0.43 pounds per square inch. In some embodiments, the tensile strength of the tissue interface 120 may be at least 10 pounds per square inch. The tissue interface 120 may have a tear strength of at least 2.5 pounds per inch. In some embodiments, the tissue interface can be a foam composed of a polyol (such as a polyester or a polyether), an isocyanate (such as toluene diisocyanate), and a polymerization modifier (such as an amine and a tin compound). In some examples, the tissue interface 120 can be a reticulated polyurethane foam, such as GRANUFOAM®, both available from Kinetic Concepts, Inc. of San Antonio, Texas. TM Dressing or VACVERAFLO TM Found in dressings.

[0064] The thickness of the tissue interface 120 may also vary depending on the needs of the prescribed treatment. For example, the thickness of the tissue interface may be reduced to reduce tension on the surrounding tissue. The thickness of the tissue interface 120 may also affect the conformability of the tissue interface 120. In some embodiments, a thickness in the range of about 5 mm to 10 mm may be suitable.

[0065] The tissue interface 120 may be hydrophobic or hydrophilic. In examples where the tissue interface 120 may be hydrophilic, the tissue interface 120 may also wick fluid away from the tissue site while continuing to distribute negative pressure to the tissue site. The wicking properties of the tissue interface 120 may wick fluid away from the tissue site by capillary flow or other wicking mechanisms. Examples of materials that may be suitable hydrophilic materials are polyvinyl alcohol, open cell foams such as VACWHITEFOAM available from Kinetic Concepts, Inc. of San Antonio, Texas. TM Dressings. Other hydrophilic foams may include those made from polyethers. Other foams that may exhibit hydrophilic characteristics include hydrophobic foams that have been treated or coated to render them hydrophilic.

[0066] In some embodiments, the tissue interface 120 may be composed of a bioabsorbable material. Suitable bioabsorbable materials may include, but are not limited to, polymer blends of polylactic acid (PLA) and polyglycolic acid (PGA). Polymer blends may also include, but are not limited to, polycarbonate, polyfumarate, and caprolactone. The tissue interface 120 may also be used as a scaffold for new cell growth, or a scaffold material may be used in conjunction with the tissue interface 120 to promote cell growth. A scaffold is typically a material or structure for enhancing or promoting cell growth or tissue formation, such as a three-dimensional porous structure that provides a template for cell growth. Illustrative examples of scaffold materials include calcium phosphate, collagen, PLA / PGA, coral hydroxyapatite, carbonate, or treated allograft material.

[0067] In some embodiments, the cover 125 can provide a bacterial barrier and prevent physical trauma. The cover 125 can also be composed of a material that can reduce evaporative losses and provide a fluid seal between two components or two environments (such as between the treatment environment and the local external environment). The cover 125 can include or consist of, for example, an elastomeric film or membrane that can provide a seal sufficient to maintain negative pressure at the tissue site for a given negative pressure source.

[0068] In some exemplary embodiments, the cover 125 may be a polymer cover cloth that is permeable to water vapor but impermeable to liquids, such as a polyurethane film. In other embodiments, the cover 125 may be impermeable to both water vapor and liquids. Such a cover cloth generally has a thickness in the range of 25 microns to 50 microns. For permeable materials, the permeability should generally be low enough so that the desired negative pressure can be maintained. The cover 125 may include, for example, one or more of the following materials: polyurethane (PU), such as hydrophilic polyurethane; cellulose; hydrophilic polyamide; polyvinyl alcohol; polyvinyl pyrrolidone; hydrophilic acrylic resin; silicone, such as hydrophilic silicone elastomer; natural rubber; polyisoprene; styrene-butadiene rubber; chloroprene rubber; polybutadiene; nitrile rubber; butyl rubber; ethylene-propylene rubber; ethylene propylene diene monomer; chlorosulfonated polyethylene; polysulfide rubber; ethylene vinyl acetate (EVA); copolyester; and polyether block polyamide copolymer. Such materials are commercially available, for example, from 3M Company, Minneapolis Minnesota. Drapes; polyurethane (PU) drapes commercially available from Avery Dennison Corporation, Pasadena, California; polyether block polyamide copolymers (PEBAX), commercially available, for example, from Arkema SA, Colombes, France; and Exopack Advanced Coatings, commercially available from Exopack Advanced Coatings, Wrexham, United Kingdom 2301 and 2327 polyurethane film. In some embodiments, the cover 125 may include a 2600 g / m 2 / 24 hours MVTR (stand-up cup technology) and a thickness of about 30 microns 2301.

[0069] Attachment means can be used to attach cover 125 to an attachment surface, such as an undamaged epidermis, a gasket, or another cover. Attachment means can take many forms. For example, attachment means can be a medically acceptable pressure-sensitive adhesive that is configured to bond cover 125 to the epidermis around the tissue site. In some embodiments, for example, some or all of cover 125 may be coated with an adhesive, such as an acrylic adhesive, that may have a coating amount of about 25 grams per square meter to 65 grams per square meter (gsm). In some embodiments, a thicker adhesive or a combination of adhesives may be applied to improve sealing and reduce leakage. Other exemplary embodiments of attachment means may include double-sided tape, paste, aqueous colloid, hydrogel, silicone gel, or organogel.

[0070] Solution source 145 may also be representative of a container, canister, pouch, bag, or other storage component that may provide a solution for infusion therapy. The composition of the solution may vary depending on the 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.

[0071] In operation, the tissue interface 120 can be placed in, above, above, or otherwise close to a tissue site. For example, if the tissue site is a wound, the tissue interface 120 can partially or completely fill the wound, or the tissue interface can be placed above the wound. The cover 125 can be placed above the tissue interface 120 and sealed to an attachment surface near the tissue site. For example, the cover 125 can be sealed to the undamaged epidermis around the tissue site. Therefore, the dressing 110 can provide a sealed treatment environment close to the tissue site, which is substantially isolated from the external environment, and the negative pressure source 105 can reduce the pressure in the sealed treatment environment.

[0072] The process of reducing pressure may be illustratively described herein as, for example, "delivering," "distributing," or "generating" negative pressure. Typically, exudates and other fluids flow along a fluid path in the direction of lower pressure. Thus, the term "downstream" typically means a location in a fluid path that is relatively closer to a negative pressure source or farther from a positive pressure source. Conversely, the term "upstream" means a location that is relatively farther from a negative pressure source or closer to a positive pressure source.

[0073] Negative pressure applied across a tissue site through tissue interface 120 in a sealed treatment environment can induce macro- and micro-strains in the tissue site. Negative pressure can also remove exudate and other fluids from the tissue site that may be collected in container 115.

[0074] In some embodiments, the controller 130 may receive and process data from one or more sensors (such as the first sensor 135). The controller 130 may also control the operation of one or more components of the treatment system 100 to manage the pressure delivered to the tissue interface 120. In some embodiments, the controller 130 may include an input for receiving a desired target pressure, and may be programmed to process data related to the setting and input of the target pressure to be applied to the tissue interface 120. In some exemplary embodiments, the target pressure may be a fixed pressure value set by an operator as the target negative pressure desired for treatment at the tissue site and then provided as an input to the controller 130. The target pressure may vary from tissue site to tissue site based on the type of tissue forming the tissue site, the type of injury or wound (if any), the patient's medical condition, and the preferences of the attending physician. After selecting the desired target pressure, the controller 130 may operate the negative pressure source 105 in one or more control modes based on the target pressure, and may receive feedback from one or more sensors to maintain the target pressure at the tissue interface 120.

[0075] In some embodiments, the controller 130 may have a continuous pressure mode, wherein the negative pressure source 105 is operated to provide a constant target negative pressure during the treatment duration or until manual deactivation. Additionally or alternatively, the controller may have an intermittent pressure mode. In some exemplary embodiments, the controller 130 may operate the negative pressure source 105 to cycle between the target pressure and the atmospheric pressure. For example, the target pressure may be set to a value of 135 mmHg for a specified period of time (e.g., 5 minutes), followed by deactivation of a specified period of time (e.g., 2 minutes). The cycle may be repeated by activating the negative pressure source 105, which may form a square wave pattern between the target pressure and the atmospheric pressure.

[0076] In some exemplary embodiments, the increase in negative pressure from ambient pressure to target pressure may not be instantaneous. For example, the negative pressure source 105 and the dressing 110 may have an initial rise time. The initial rise time may vary depending on the type of dressing and treatment device used. For example, the initial rise time of one treatment system may be in the range of about 20 mmHg / second-30 mmHg / second, and the initial rise time of another treatment system may be in the range of about 5 mmHg / second-10 mmHg / second. If the treatment system 100 is operated in an intermittent mode, the repetitive rise time may be a value substantially equal to the initial rise time.

[0077] In some exemplary dynamic pressure control modes, the target pressure may vary over time. For example, the target pressure may vary in the form of a triangular waveform, varying between a negative pressure of 50 mmHg to 135 mmHg, wherein the rising rate of the negative pressure is set to a rate of +25 mmHg / minute, and the falling rate is set to -25 mmHg / minute. In other embodiments of the treatment system 100, the triangular waveform may vary between a negative pressure of 25 mmHg to 135 mmHg at a rising rate of about +30 mmHg / minute and a falling rate of about -30 mmHg / minute.

[0078] In some embodiments, the controller 130 can control or determine a variable target pressure in a dynamic pressure mode, and the variable target pressure can vary between a maximum pressure value and a minimum pressure value, which can be set as a range of desired negative pressures as input specified by the operator. The variable target pressure can also be processed and controlled by the controller 130, which can change the target pressure according to a predetermined waveform (such as a triangular waveform, a sine waveform, or a sawtooth waveform). In some embodiments, the waveform can be set by the operator to a predetermined or time-varying negative pressure desired for treatment.

[0079] In some embodiments, the controller 130 may receive and process data, such as data related to the instillation solution provided to the tissue interface 120. Such data may include the type of instillation solution specified by the clinician, the volume of the fluid or solution to be instilled into the tissue site ("fill volume"), and the amount of time specified for leaving the solution at the tissue site before applying negative pressure to the tissue site ("residence time"). The fill volume may be, for example, between 10mL and 500mL, and the residence time may be between one second and 30 minutes. The controller 130 may also control the operation of one or more components of the treatment system 100 to instill the solution. For example, the controller 130 may manage the fluid distributed to the tissue interface 120 from the solution source 145. In some embodiments, the fluid may be instilled into the tissue site by applying negative pressure from the negative pressure source 105 to reduce the pressure at the tissue site, and the solution may be sucked into the tissue interface 120. In some embodiments, the solution may be instilled into the tissue site by applying positive pressure from the positive pressure source 150 to move the solution from the solution source 145 to the tissue interface 120. Additionally or alternatively, the solution source 145 may be elevated to a height sufficient to allow gravity to move the solution into the tissue interface 120 .

[0080] The controller 130 can also control the fluid dynamics of the instillation at 425 by providing a continuous flow of solution or an intermittent flow of solution. Negative pressure can be applied to provide a continuous flow of solution or an intermittent flow. The application of negative pressure can be implemented to provide a continuous pressure operating mode to achieve a continuous flow rate of the instillation solution through the tissue interface 120, or the application of negative pressure can be implemented to provide a dynamic pressure operating mode to change the flow rate of the instillation solution through the tissue interface 120. Alternatively, the application of negative pressure can be implemented to provide an intermittent operating mode to allow the instillation solution to stay at the tissue interface 120. In the intermittent mode, a specific fill volume and residence time can be provided, which depends on, for example, the type of tissue site being treated and the type of dressing being utilized. After or during the instillation of the solution, negative pressure therapy can be applied. The controller 130 can be used to select the operating mode and the duration of the negative pressure therapy before starting another instillation cycle by instilling more solution.

[0081] Figure 2 yes Figure 1 10 is an exploded view of an example of a dressing 110, illustrating additional details that may be associated with some embodiments. The dressing 110 may include a sealing layer or wound contact layer 202, a first film layer 204, a manifold layer or manifold 206, a second film layer 208, and a drape or cover 125. The wound contact layer 202 may be formed of a soft, pliable material (such as a suitable gel material) suitable for providing a fluid seal with a tissue site, and may have a substantially flat surface. In some embodiments, the wound contact layer 202 may include, but is not limited to, silicone gel, soft silicone, hydrocolloid, hydrogel, polyurethane gel, polyolefin gel, hydrogenated styrene copolymer gel, foaming gel, soft closed-cell foam (such as, polyurethane and polyolefin coated with an adhesive), polyurethane, polyolefin or hydrogenated styrene copolymer. In some embodiments, the wound contact layer 202 may have a thickness in the range of about 200 microns to about 1,000 microns. In some embodiments, the wound contact layer 202 may be formed of a hydrophobic or hydrophilic material.

[0082] In some embodiments, the wound contact layer 202 may include or be formed of a hydrophobic material or a hydrophobic coating material. For example, the wound contact layer 202 may be formed by coating a spacer material (such as a woven mesh, a nonwoven mesh, a molded mesh, or an extruded mesh) with a hydrophobic material (such as soft silicone).

[0083] The wound contact layer 202 may have a first surface 210 and a second surface 212 opposite the first surface 210. The wound contact layer 202 may also include a peripheral portion or perimeter 214 defined by the outer perimeter of the wound contact layer 202, and a central portion 215 including a treatment hole 216 formed through the wound contact layer 202. In some embodiments, the treatment hole 216 may have a contour that is complementary or corresponding to the outer perimeter of the manifold 206. The wound contact layer 202 may also include a plurality of holes 218 formed through the wound contact layer 202. In some embodiments, the plurality of holes 218 may be formed through an area of ​​the wound contact layer 202 between the treatment hole 216 and the perimeter 214.

[0084] In some embodiments, the perimeter 214 of the wound contact layer 202 may be or may include a sensor 220. The sensor 220 may be configured to change color to indicate a sensed parameter when the sensor 220 is acted upon by a light source. For example, in some embodiments, the sensor 220 may be configured to sense oxygen levels. When acted upon by a light source, the sensor 220 may change color. In some embodiments, the intensity of the color may depend on the sensed parameter, such as the sensed oxygen level. For example, when the sensed oxygen level is relatively low, the sensor 220 may emit a strong light or strong color, and when the sensed oxygen level is relatively high, the sensor 220 may emit a relatively dark or dim light or color. In some embodiments, the sensor 220 may emit a basic level color when exposed to the surrounding environment. Therefore, when the sensor 220 senses that the oxygen level is lower than the oxygen level of the surrounding environment, the sensor 220 may emit a color that is stronger or brighter than the basic level color. When the sensor 220 senses that the oxygen level is higher than the oxygen level of the surrounding environment, the sensor 220 may emit a color that is not as strong or bright as the basic level color. In other embodiments, the sensor 220 may emit light different from that described above, but still change when exposed to a light source so that the sensed parameter is displayed by the sensor 220. In some embodiments, the sensor 220 may be configured to sense other parameters, such as wound temperature, pH level, or the presence of a fluid. In embodiments where the sensor 220 is configured to sense pH levels, the sensor 220 may function substantially as described above with respect to sensing oxygen. For example, the intensity of the emitted light may depend on the sensed pH level. In embodiments where the sensor 220 is configured to detect the presence of a fluid, the sensor 220 may be partially or completely opaque when dry, and may be transparent when exposed to a fluid. When the sensor 220 changes from opaque to transparent, the sensor 220 has detected the presence of a fluid.

[0085] In some embodiments, the sensor 220 can be a dye that can be integrated or blended into the dressing 110. For example, in some embodiments, the sensor 220 can be integrated into the periphery 214 of the wound contact layer 202. In other embodiments, the sensor 220 can be a film containing a luminescent material (such as a transition metal ligand or a chemical sensing material). In some embodiments, the chemical sensing material can be an oxygen sensing material or molecule or a pH sensing material or molecule. The film can be coupled to or deposited on a layer of the dressing 110 (such as the wound contact layer 202). In some embodiments, the sensor 220 can be an oxygen sensing film. The oxygen sensing film can include a polymer matrix in which the oxygen sensing molecules are dissolved. Biocompatible silicones and biocompatible oxygen sensing materials can be mixed or blended with transparent medical grade polymers to produce a desired oxygen sensing film. In some embodiments, the oxygen sensing molecule can be a porphyrin. The oxygen sensing film can include a low oxygen permeability polymer or a high oxygen permeability polymer. The low oxygen permeability polymer may include at least one of polyvinyl alcohol, ethylene vinyl alcohol, polyacrylonitrile, polyvinylidene chloride, or another similar material. The high oxygen permeability polymer may include at least one of silicone, a polyolefin elastomer, or another similar material. In other embodiments, the sensor 220 may be a biocompatible oxygen sensing material (such as a porphyrin as described above) printed directly onto a layer of the dressing 110 (such as the wound contact layer 202).

[0086] like Figure 2 As shown, the sensor 220 is deposited onto the second surface 212 of the wound contact layer 202. In some embodiments, the sensor 220 may extend around the perimeter 214 of the wound contact layer 202, and in other embodiments, the sensor 220 may be deposited onto the entire second surface 212 of the wound contact layer 202. In other embodiments, the sensor 220 may be deposited at discrete locations on the second surface 212 of the wound contact layer 202. The sensor 220 may be at any location on the second surface 212 of the wound contact layer 202 that will be located proximate to a peri-wound region of the tissue site when the dressing 110 is disposed on the tissue site. When the dressing 110 is disposed at the tissue site, the sensor 220 may be configured to sense a parameter in a peri-wound region of the wound contact layer 202 coupled to the wound at the tissue site. For example, the sensor 220 may be configured to sense an oxygen level at a peri-wound region of the tissue site when the dressing 110 is coupled to the tissue site.

[0087] In some embodiments, the plurality of holes 218 may be formed by cutting, perforating, or applying localized radiofrequency or ultrasonic energy through the wound contact layer 202. In some embodiments, the plurality of holes 218 may be formed by other suitable techniques for forming openings or perforations in the wound contact layer 202. In some embodiments, the plurality of holes 218 may have a uniform distribution pattern. In other embodiments, the plurality of holes 218 may be randomly distributed. In some embodiments, the plurality of holes 218 may have any combination of shapes, including circles, squares, stars, ellipses, polygons, slits, complex curves, straight shapes, or triangles.

[0088] In some embodiments, each of the plurality of holes 218 may have uniform or similar geometrical properties. For example, each of the plurality of holes 218 may be a circular hole and have substantially the same diameter. In some embodiments, each of the plurality of holes 218 may have a diameter in the range of about 1 mm to about 20 mm.

[0089] In some embodiments, the geometric characteristics of the plurality of holes 218 may vary. For example, the diameter of the plurality of holes 218 may vary depending on the positioning of the holes 218 in the wound contact layer 202. In some embodiments, at least some of the plurality of holes 218 may have a diameter in the range of about 5 mm to about 10 mm. In some embodiments, at least some of the plurality of holes 218 may have a diameter in the range of about 7 mm to about 9 mm. In some embodiments, the wound contact layer 202 may include corners, and the plurality of holes 218 disposed at or near these corners may have a diameter in the range of about 7 mm to about 8 mm.

[0090] In some embodiments, at least some of the plurality of holes 218 positioned proximate to the perimeter 214 may have interiors that are cut or exposed at the perimeter 214 and that are laterally connected to the perimeter 214 in a lateral direction (relative to the first surface 210 and / or the second surface 212). In some embodiments, the lateral direction may refer to a direction that is in the same plane as the first surface 210 and / or the second surface 212 and extends toward the perimeter 214. In some embodiments, at least some of the plurality of holes 218 positioned proximate to or at the perimeter 214 may be substantially equally spaced around the perimeter 214. Alternatively, in some embodiments, the spacing of the plurality of holes 218 proximate to or at the perimeter 214 may be irregularly spaced.

[0091] The first film layer 204 may include a suitable structure for controlling or managing fluid flow. In some embodiments, the first film layer 204 may be a fluid control layer, which includes an elastomeric material that is impermeable to liquid and permeable to steam. In some embodiments, the first film layer 204 may be formed by a polymer film or include a polymer film. For example, in some embodiments, the first film layer 204 may be formed by a polyolefin film or include a polyolefin film, such as a polyethylene film. In some embodiments, the first film layer 204 may be substantially transparent or optically transparent. In some embodiments, the first film layer 204 may be formed by the same material as the cover 125 or include the same material as the cover. In some embodiments, the first film layer 204 may be formed by or include a biocompatible polyurethane film tested and certified according to the USPVI grade standard. In some embodiments, the first film layer 204 may also have a smooth or matte surface texture. In some embodiments, the first film layer 204 may have a smooth or glossy finish equal to or exceeding the B3 grade according to the Plastics Industry Association (SPI) standard. In some embodiments, the surface of the first film layer 204 can be a substantially flat surface with a height variation ranging from about 0.2 millimeters to about 1 centimeter.

[0092] In some embodiments, the first film layer 204 may be hydrophobic. The hydrophobicity of the first film layer 204 may vary, but in some examples may have a contact angle with water of at least 90 degrees. In some embodiments, the first film layer 204 may have a contact angle with water of no more than 150 degrees. In some embodiments, the contact angle of the first film layer 204 with water may be in the range of about 90 degrees to about 120 degrees, or in the range of about 120 degrees to about 150 degrees. The water contact angle can be measured using any standard equipment. Although manual goniometers can be used to visually approximate contact angles, contact angle measuring instruments can typically involve integrated systems that include a level, a liquid dropper (such as a syringe), a camera, and software designed to more accurately and precisely calculate contact angles. Non-limiting examples of such integrated systems include and Systems, all commercially available from First Ten Angstroms, Inc., Portsmouth, Virginia, and DTA25, DTA30 and DTA100 systems, all commercially available from Kruss GmbH, Hamburg, Germany. Unless otherwise specified, the water contact angles herein are measured on a horizontal sample surface with a static drop added from a height of no more than five centimeters in air using deionized water and / or distilled water at 20°C-25°C and 20%-50% relative humidity. The contact angles herein represent an average of five to nine measurements, with the highest and lowest measurements discarded. In some embodiments, the hydrophobicity of the first film layer 204 can be further enhanced with a hydrophobic coating of other materials such as silicones and fluorocarbons.

[0093] The first film layer 204 may also be suitable for welding to other layers, including the manifold 206 and the second film layer 208. In some embodiments, the first film layer 204 may be suitable for welding to polymers (such as polyurethanes, polyurethane films, and polyurethane foams) using heat welding, radio frequency (RF) welding, ultrasonic welding, or other methods. RF welding may be particularly suitable for more polar materials such as polyurethanes, polyamides, polyesters, and acrylates. Sacrificial polar interfaces may be used to facilitate RF welding of less polar film materials (such as polyethylene).

[0094] The surface density of the first film layer 204 can vary depending on the prescribed treatment or application. In some embodiments, a surface density of less than 40 grams per square meter may be suitable. In some embodiments, the surface density of the first film layer 204 can be in the range of about 20 grams per square meter to about 30 grams per square meter.

[0095] In some embodiments, the first film layer 204 may be formed by a hydrophobic polymer or include a hydrophobic polymer, such as a polyethylene film. The simple and inert structure of polyethylene provides a surface that hardly interacts (if any) with biological tissue and fluid, and provides a surface that can promote free flow of liquid and show low adhesion to tissue and fluid, and these characteristics may be particularly advantageous for many applications. In some embodiments, the first film layer 204 may be formed by other polymer films, such as polyurethane, acrylic, polyolefin (such as cyclic olefin copolymer), polyacetate, polyamide, polyester, copolyester, PEBAX block copolymer, thermoplastic elastomer, thermoplastic vulcanizate, polyether, polyvinyl alcohol, polypropylene, polymethylpentene, polycarbonate styrene, silicone, fluoropolymer and acetate. In some embodiments, the first film layer 204 may have a thickness within the range of about 20 microns to about 500 microns. In some embodiments, the first film layer 204 may have a thickness of about 23 microns, about 25 microns, about 100 microns, about 250 microns, about 300 microns and about 500 microns. In some embodiments, the first film layer 204 may include a polar film suitable for lamination to a polyethylene film, such as polyamides, copolyesters, ionomers, and acrylics. In some embodiments, the first film layer 204 may include a tie layer to improve the bonding between the polyethylene and polar film layers. In some embodiments, the tie layer may include ethylene vinyl acetate or modified polyurethane. In some embodiments, the first film layer 204 may include ethyl methyl acrylate (EMA) film.

[0096] The first film layer 204 may have a first surface 222 and a second surface 224 opposite the first surface 222. The first film layer 204 may also include a perimeter 226 defined by the outer perimeter of the first film layer 204. In some embodiments, the perimeter 226 may be stadium-shaped, disc-shaped, rectangular, or oblong. The first film layer 204 may also include one or more fluid channels 228 formed through the first film layer 204, and they may be evenly or randomly distributed across the first film layer 204.

[0097] In some embodiments, fluid channel 228 can be used as a two-way and fluid responsive valve. For example, each fluid channel 228 can be an elastic channel that is stress-free under normal circumstances to prevent or substantially reduce fluid flow through fluid channel 228, and can expand or open in response to a pressure gradient applied across fluid channel 228 to allow fluid to flow through fluid channel 228. In some embodiments, fluid channel 228 may include perforations formed in first film layer 204. Perforations can be formed by removing material from first film layer 204 or cutting through first film layer 204. In some embodiments, cutting through first film layer 204 can deform the edges of perforations. In some embodiments, fluid channel 228 can be narrow enough to form a seal or fluid restriction, thereby significantly reducing or preventing fluid from flowing through fluid channel 228, especially in the absence of a pressure difference. In some embodiments, one or more fluid channels in fluid channel 228 can be an elastic valve that is usually closed when unstrained to prevent liquid from flowing through the valve, and can be opened in response to a pressure gradient. In some embodiments, the fluid channel 228 may include a fenestration formed through the first film layer 204. The fenestration may be formed by removing material from the first film layer 204, but the amount of material removed and the resulting size of the fenestration may be at most an order of magnitude smaller than a perforation and may not deform the edges.

[0098] In some embodiments, fluid channel 228 may include one or more slits, slots, or a combination of slits and slots in first film layer 204. In some embodiments, fluid channel 228 may include a linear slot having a length less than about five millimeters and a width less than about two millimeters. In some embodiments, the length may be at least about two millimeters, and the width may be at least about 0.5 millimeters. In some embodiments, the length may be in the range of about two millimeters to about five millimeters, and the width may be in the range of about 0.5 millimeters to about two millimeters, wherein the tolerance is about 0.1 millimeters. In some embodiments, the length may be about three millimeters. Such dimensions and tolerances may be realized, for example, with a laser cutter. In some embodiments, the slot of such configuration may be used as an imperfect valve that significantly reduces liquid flow under normally closed or static conditions. Such grooves may form flow restrictions without being completely closed or sealed. The slot may expand or open wider in response to the pressure gradient applied across the slot to allow increased liquid to flow through the slot.

[0099] In some embodiments, the fluid channel 228 may include a linear slit having a length less than about five millimeters. In some embodiments, the length of the linear slit may be at least about two millimeters. In some embodiments, the length of the linear slit may be in the range of about two millimeters to about five millimeters, with a tolerance of about 0.1 millimeters. In some embodiments, the length of the linear slit may be about three millimeters.

[0100] In some embodiments not shown herein, the first film layer 204 may be integral with the wound contact layer 202. For example, the wound contact layer 202 may not include the treatment hole 216 and may be a continuous layer. In some embodiments, the central portion 215 of the wound contact layer 202 may include the fluid channel 228 of the first film layer.

[0101] In some embodiments, the manifold 206 can be formed as a substantially sheet-like structure having a first surface 232 and a second surface 234 opposite the first surface 232. In some embodiments, the manifold 206 can also include a perimeter 236 defined by the outer perimeter of the manifold 206. In some embodiments, the perimeter 236 of the manifold 206 can be substantially similar to or coextensive with the perimeter 226 of the first film layer 204. In some embodiments, the manifold 206 can be formed of a polyurethane sheet, such as a vacuum-formed polyurethane sheet having a thickness of about 0.5 millimeters. In some embodiments, the manifold 206 can be formed of a substantially transparent or optically transparent polymer material, thereby allowing a user to see through the manifold 206.

[0102] In some embodiments, the plurality of windows 238 may be removed from the manifold 206 and formed into a grid pattern. For example, the plurality of windows 238 may be arranged in a pattern of rows and columns. The center of each window 238 in the plurality of windows 238 may be aligned with the center of each other window 238 in the plurality of windows 238 within the row, and the center of each window 238 in the plurality of windows 238 may be aligned with the center of each other window 238 in the plurality of windows 238 within the column. In some embodiments, a plurality of legs 240 may be formed on the second surface 234 of the manifold 206. In some embodiments, the plurality of legs 240 may form a grid pattern. For example, the plurality of legs 240 may be arranged in a pattern of rows and columns. The center of each leg 240 in the plurality of legs 240 may be aligned with the center of each other leg 240 in the plurality of legs 240 within the row, and the center of each leg 240 in the plurality of legs 240 may be aligned with the center of each other leg 240 in the plurality of legs 240 within the column. In some embodiments, each row of the plurality of windows 238 can be disposed adjacent to a row of the plurality of standoffs 240, and each column of the plurality of windows 238 can be disposed adjacent to a column of the plurality of standoffs 240. In some embodiments, the plurality of windows 238 and the plurality of standoffs 240 can be arranged in a pattern such that the rows of the pattern alternate between rows of the plurality of windows 238 and rows of the plurality of standoffs 240, and the columns of the pattern alternate between columns of the plurality of windows 238 and columns of the plurality of standoffs 240.

[0103] In some embodiments, the profile of each window 238 in the plane of the first surface 232 of the manifold 206 can be substantially circular. In some embodiments, the profile of each leg 240 can be substantially circular and protrude outwardly from the plane of the second surface 234 of the manifold 206 in a substantially orthogonal manner. In some embodiments, the diameter of each window 238 in the plurality of windows 238 can be greater than the diameter of each leg 240 in the plurality of legs 240. For example, each window 238 in the plurality of windows 238 can have a diameter of about eight millimeters, and each leg 240 in the plurality of legs 240 can have a diameter of about three millimeters. In some embodiments, each leg 240 in the plurality of legs 240 can have a height in the range of about 0.5 millimeters to about 3 millimeters. In some embodiments, each leg 240 in the plurality of legs 240 can have a height of about 2.5 millimeters. In some embodiments, each leg 240 in the plurality of legs 240 can have a height of about 3 millimeters. In some embodiments, each of the plurality of legs 240 in a row may be spaced apart from adjacent legs 240 in the row by a distance of about four millimeters on center, and each of the plurality of legs 240 in a column may be spaced apart from adjacent legs 240 in the column by a distance of about four millimeters on center. In some embodiments, the plurality of legs 240 may be right cylinders with hemispherical ends, such as a half capsule, and may be formed on the second surface 234 of the manifold 206 in a direction substantially perpendicular to the second surface 234 and substantially protrude away from the second surface. In some embodiments, each of the plurality of legs 240 may have a height in a range of about 2.5 millimeters to about three millimeters.

[0104] In some embodiments, the manifold 206 can include a raised portion, such as a lip or protrusion 242. In some embodiments, the protrusion 242 can protrude outwardly from the plane of the first surface 232 of the manifold 206 in a substantially orthogonal manner. In some embodiments, the protrusion 242 can have a scaled-down profile or outline that is similar to the shape of the perimeter 236 of the manifold 206. In some embodiments, the manifold 206 can also have a border region 244 between the protrusion 242 and the perimeter 236 of the manifold. In some embodiments, the border region 244 can include any of the plurality of windows 238 or any of the plurality of legs 240.

[0105] The second film layer 208 may have a first surface 250 and a second surface 252 opposite the first surface 250. The second film layer 208 may also include a perimeter 254 defined by the perimeter of the second film layer 208. Negative pressure holes, such as holes 256, may be formed through the second film layer 208. In some embodiments, the second film layer 208 may be formed of or include any of the materials previously described with respect to the cover 125 and / or the first film layer 204.

[0106] The cover 125 may include a first surface 262 and a second surface 264 opposite the first surface 262. The cover 125 may also include a peripheral portion or perimeter 266 defined by the outer perimeter of the cover 125. In some embodiments, the cover may have a central portion 267 having a central hole 268 formed through the cover 125. In some embodiments, the cover 125 may act as a barrier between the surrounding environment and the sensor 220. For example, the cover 125 may be substantially oxygen-impermeable to prevent any oxygen from reaching the sensor 220 and affecting the sensed oxygen level at the peri-wound area of ​​the tissue site.

[0107] In some embodiments not shown herein, the second film layer 208 and the central hole 268 of the cover 125 can be omitted, and the cover 125 can be a continuous layer such that the second surface 264 of the cover 125 contacts the first surface 232 of the manifold 206. In other embodiments, the second film layer 208 can be part of the cover 125 and can be aligned with the central hole 268 of the cover 125 to create a barrier between the surrounding environment and the rest of the dressing 110.

[0108] In some embodiments, the perimeter 214 of the wound contact layer 202 can be substantially coextensive with the perimeter 266 of the cover 125. In some embodiments, the perimeter 226 of the first film layer 204, the perimeter 236 of the manifold 206, and the perimeter 254 of the second film layer 208 can be substantially coextensive. In some embodiments, the contour of the treatment hole 216 of the wound contact layer 202 can be substantially coextensive with the contour of the central hole 268 of the cover 125. In some embodiments, the contours of the treatment hole 216 and the central hole 268 can be substantially similar to the contours of the perimeter 226 of the first film layer 204, the perimeter 236 of the manifold 206, and the perimeter 254 of the second film layer 208. In some embodiments, the contours of the treatment hole 216 and the central hole 268 can be substantially similar to the contours of the perimeter 226 of the first film layer 204, the perimeter 236 of the manifold 206, and the perimeter 254 of the second film layer 208, but scaled down from these contours. In assembled form, the wound contact layer 202, the first film layer 204, the manifold 206, the second film layer 208, and the cover 125 can be stacked such that the perimeter 214 of the wound contact layer 202 is aligned with the perimeter 266 of the cover 125, and the perimeter 226 of the first film layer 204 is aligned with the perimeter 236 of the manifold 206 and the perimeter 254 of the second film layer 208. In some embodiments, the treatment hole 216 can be aligned with the central hole 268, and the perimeter 226 of the first film layer 204, the perimeter 236 of the manifold 206, and the perimeter 254 of the second film layer 208 can be positioned so that they are aligned with the contours of the treatment hole 216 and the central hole 268 and extend evenly therethrough.

[0109] In some embodiments, a portion of the first surface 210 of the wound contact layer 202 surrounding the treatment hole 216 may be coupled to a portion of the second surface 224 of the first film layer 204 near the perimeter 226, and a portion of the second surface 264 of the cover 125 surrounding the central hole 268 may be coupled to a portion of the first surface 250 of the second film layer 208 near the perimeter 254. In some embodiments, a portion of the first surface 210 of the wound contact layer 202 between the perimeter 214 and the treatment hole 216 may be coupled to a portion of the second surface 264 of the cover 125 between the perimeter 266 and the central hole 268.

[0110] Some examples of the dressing 110 may also include a dressing interface 270 and a fluid conductor 272. In various embodiments, the fluid conductor 272 may be a flexible tube, one end of which may be fluidly coupled to the dressing interface 270. In various embodiments, the dressing interface 270 may be an elbow connector that may be placed over the aperture 256 to provide a fluid path between the fluid conductor 272 and the interior of the dressing 110.

[0111] In some embodiments, the dressing 110 may also include a release liner 278 to protect the wound contact layer 202 and the adhesive coated on the second surface 264 of the cover 125 prior to use. The release liner 278 may also provide stiffness to assist, for example, in the deployment of the dressing 110. In various embodiments, the release liner may include polyethylene terephthalate (PET) or a similar polar semi-crystalline polymer. Using a polar semi-crystalline polymer for the release liner 278 may substantially prevent the dressing 110 from wrinkling or other deformation. The polar semi-crystalline polymer may be highly oriented and resist softening, swelling, or other deformation that may occur when an object contacts the layers and / or components of the dressing 110 or when the dressing 110 is subjected to temperature or environmental changes or during sterilization. In addition, a release agent may be disposed on the first surface 280 of the release liner 278, the release agent being configured to contact the second surface 212 of the wound contact layer 202 and the adhesive disposed on the second surface 264 of the cover 125. For example, the release agent may be a silicone coating and may have a release coefficient suitable for facilitating manual removal of the release liner 278 without damaging or deforming the dressing 110. In various embodiments, the release agent may be a fluorocarbon or a fluorosilicone. In various embodiments, the release liner 278 may be uncoated or may otherwise be used without a release agent.

[0112] Figure 3 yes Figure 2 206, the first film layer 204 and / or the wound contact layer 202 can be substantially transparent or optically transparent, thereby allowing visualization of the layers of the dressing 110 and visualization of the window 238 through the manifold 206. In some embodiments, the sensor 220 can also be visible through the cover 125, such that when the dressing 110 is acted upon by a light source, light or color can be observed through the cover 125 and the wound contact layer 202.

[0113] Figure 4 is an example Figure 3 A cross-sectional view of the dressing 110 of FIG. 4 taken along line 4-4 applied to a tissue site 402 and illustrating the Figure 1 In some embodiments, the second surface 264 of the cover 125 can be coated with an adhesive layer 404, and at least a portion of the cover 125 can be coupled to at least a portion of the first surface 210 of the wound contact layer 202 using the adhesive layer 404. The adhesive layer 404 can be the adhesive layer 264 described previously with reference to Figure 1Any of the attachment means discussed. In some embodiments, a portion of the second surface 264 of the cover 125 can be coupled to a portion of the first surface 250 of the second film layer 208 by the adhesive layer 404, for example at the perimeter 254.

[0114] In some applications, the dressing 110 may be applied to the tissue site 402 to cover the wound 406. The tissue site 402 may be or may include a defect or targeted treatment site, such as the wound 406, which may be partially or completely filled or covered by the dressing 110. In some examples, the wound 406 may be in the epidermis 408. In some examples, the wound 406 may extend through the epidermis 408 and into the dermis 410. In other examples, the wound 406 may extend through the epidermis 408 and the dermis 410 and into the subcutaneous tissue 412. In some embodiments, at least a portion of the second surface 212 of the wound contact layer 202 may contact a portion of the epidermis 408 surrounding the wound 406, such as the periwound area 414. At least a portion of the second surface 224 of the first film layer 204 may be placed within the wound 406, above the wound, on the wound, against the wound, or otherwise placed close to the wound.

[0115] In operation, negative pressure may be provided to the wound 406, and / or fluid may be removed from the wound 406 by the negative pressure source 105 of the treatment unit 160 through the dressing interface 270 and the fluid conductor 272. When the dressing 110 is applied to the tissue site 402, the sensor 220 may be in contact with the peri-wound area 414. The sensor 220 may be configured to detect a parameter at the peri-wound area 414. For example, the sensor 220 may be configured to detect an oxygen level at the peri-wound area 414. In other embodiments, the sensor 220 may be configured to detect another parameter, such as pH or fluid level at the peri-wound area 414.

[0116] Figure 5A Shows Figure 1 A perspective view of another example of a dressing 110 illustrating additional details that may be associated with some embodiments. Figure 3 , the cover 125 , the second film layer 208 , the manifold 206 , the first film layer 204 , and / or the wound contact layer 202 may be substantially transparent or optically transparent, thereby allowing visualization of the layers of the dressing 110 and visualization of the window 238 through the manifold 206 .

[0117] The dressing 110 may include a peri-wound sensor 502. In some embodiments, the peri-wound sensor 502 may be disposed on or within the wound contact layer 202. For example, in some embodiments, the peri-wound sensor 502 may be disposed between the second surface 264 of the cover 125 and the first surface 210 of the wound contact layer 202. In other embodiments, the peri-wound sensor 502 may be combined or blended into the wound contact layer 202, or located near the second surface 212 of the wound contact layer 202. The peri-wound sensor 502 may be similar to or identical to the sensor 220 described above. For example, the peri-wound sensor 502 may be configured to sense a parameter at a peri-wound region of a tissue site, such as an oxygen level at a peri-wound region 414 of a tissue site 402.

[0118] In some embodiments, the dressing 110 can also include at least one wound sensor 504. In some embodiments, the wound sensor 504 can be disposed between the second surface 252 of the second membrane layer 208 and the first surface 232 of the manifold 206. In other embodiments, the wound sensor 504 can be located at a different location within the dressing 110, but can still be located near a wound at a tissue site, such as the wound 406 at the tissue site 402. The wound sensor 504 can be similar to or identical to the sensor 220 described above. For example, the wound sensor 504 can be configured to sense a parameter at a wound at a tissue site, such as an oxygen level at the wound 406 at the tissue site 402.

[0119] refer to Figure 5B , showing Figure 5A Another embodiment of a dressing 110. The dressing 110 may be similar to Figure 5A The dressing 110 of claim 110 may further include a periwound sensor cover 510 and a wound sensor cover 512. The periwound sensor cover 510 and the wound sensor cover 512 may be substantially transparent or optically transparent, thereby allowing visualization of the dressing 110 through the periwound sensor cover 510 and the wound sensor cover 512. The periwound sensor cover 510 may be coupled to or integral with the cover 125 and may be disposed proximate to the periwound sensors 502. The periwound sensor cover 510 may be removably coupled to the cover 125 such that each of the periwound sensor covers 510 may be removed to expose one of the periwound sensors 502 within the dressing 110.

[0120] In some embodiments, the wound sensor cover 512 may be coupled to or integral with the second film layer 208 and may be disposed proximate to the wound sensor 504. The wound sensor cover 512 may be removably coupled to the second film layer 208 such that the wound sensor cover may be removed to expose the wound sensor 504 within the dressing 110.

[0121] In some embodiments, the peri-wound sensor cover 510 and the wound sensor cover 512 may be included in the dressing 110 so that the peri-wound sensors 502 and the wound sensors 504 may be added to or removed from the dressing 110 when the dressing 110 is deployed at a tissue site, such as the tissue site 402. The peri-wound sensor cover 510 and the wound sensor cover 512 may be both water vapor and liquid impermeable to provide a fluid seal with the cover 125 and the second membrane layer 208, respectively. The peri-wound sensor cover 510 and the wound sensor cover 512 may isolate the peri-wound sensors 502 and the wound sensors 504 from the outside or surrounding environment so that the peri-wound sensors 502 and the wound sensors 504 may sense parameters at the peri-wound region 414 and the wound 406 of the tissue site 402.

[0122] Figure 5C 5C-5C is a cross-sectional view of the dressing 110 taken along line 5C-5C. The periwound sensor 502 may be disposed within the wound contact layer 202, and the periwound sensor cover 510 may be coupled to the cover 125. The periwound sensor cover 510 may include a flap 520. The flap 520 may enable a healthcare provider or another user to easily remove the periwound sensor cover 510 from the dressing 110. When the periwound sensor cover 510 is removed from the dressing 110, the periwound sensor 502 may be accessible through the cover 125.

[0123] Figure 5D 5D-5D is a cross-sectional view of the dressing 110 taken along line 5D-5D. The wound sensor 504 can be disposed proximate to the first surface 232 of the manifold 206. In other embodiments, the wound sensor 504 can be disposed at a different location, such as in one of the plurality of windows 238 of the manifold 206. The wound sensor cover 512 can be coupled to the second membrane layer 208. The wound sensor cover 512 can include a flap 522 similar to the flap 520 of the peri-wound sensor cover 510.

[0124] Figure 6A-6F is a cross-sectional view of the dressing 110 showing peri-wound sensors 502 disposed at different locations within the dressing 110 . Fig. 6AThe periwound sensor 502 is shown disposed within one of the plurality of apertures 218 of the wound contact layer 202. The periwound sensor 502 may be in direct contact with the periwound region 414 of the tissue site 402 when the dressing 110 is disposed at a tissue site, such as the tissue site 402.

[0125] Figure 6B A periwound sensor 502 is shown molded or blended into the wound contact layer 202. When the dressing 110 is disposed at the tissue site 402, the periwound sensor 502 may be separated from the plurality of apertures 218 and may be in direct contact with the periwound region 414 of the tissue site 402.

[0126] Figure 6C A periwound sensor 502 is shown disposed proximate the first surface 210 of the wound contact layer 202. When the dressing 110 is disposed at the tissue site 402, the periwound sensor 502 may be disposed proximate one of the plurality of apertures 218 but may be separated from the periwound region 414 of the tissue site 402.

[0127] Fig.6D A periwound sensor 502 is shown disposed between the first surface 210 of the wound contact layer 202 and the second surface 264 of the cover 125. The periwound sensor 502 may be isolated from the plurality of apertures 218 such that the periwound sensor 502 is isolated from the periwound region 414 of the tissue site 402 when the dressing 110 is disposed at the tissue site 402.

[0128] Fig. 6E A peri-wound sensor 502 coupled to the first surface 262 of the cover 125 is shown opposite one of the plurality of holes 218 of the wound contact layer 202. A portion 602 of the cover 125 may be disposed within one of the plurality of holes 218 such that a first surface 604 of the peri-wound sensor 502 is flush with the first surface 262 of the cover 125. In some embodiments, the peri-wound sensor 502 may be isolated from the peri-wound region 414 of the tissue site 402 to provide a baseline or atmospheric oxygen level reading when the sensor is acted upon by a light source. In some embodiments, multiple peri-wound sensors 502 may be used such that parameters may be measured at multiple locations using the peri-wound sensors 502.

[0129] Fig. 6F A peri-wound sensor 502 is shown coupled to the first surface 262 of the cover 125 opposite one of the plurality of apertures 218 of the wound contact layer 202. Fig. 6EAs shown, the periwound sensor 502 can be isolated from the periwound region 414 of the tissue site 402 to provide a baseline or atmospheric oxygen level reading when the sensor is acted upon by a light source. In some embodiments, multiple periwound sensors 502 can be used so that parameters can be measured at multiple locations using the periwound sensors 502.

[0130] Figure 7A-7F is a cross-sectional view of the dressing 110 showing wound sensors 504 disposed at different locations within the dressing 110 . Fig. 7A The wound sensor 504 is shown coupled to the second surface 224 of the first membrane layer 204. The first membrane layer 204 proximate the wound sensor 504 can be pushed into the manifold 206 such that the first surface 222 of the first membrane layer 204 is coupled to at least one of the plurality of legs 240 and the second surface 234 of the manifold 206 such that the wound sensor 504 is flush with the second surface 224 of the first membrane layer 204. When the dressing 110 is disposed at the tissue site 402, the wound sensor 504 can be in direct contact with the wound 406 of the tissue site 402.

[0131] Figure 7B A wound sensor 504 is shown disposed between the manifold 206 and the first film layer 204. The wound sensor 504 can be disposed between the plurality of legs 240, and at least a portion of the wound sensor 504 can be proximate to one of the plurality of windows 238 of the manifold 206. When the dressing 110 is disposed at the tissue site 402, the wound sensor 504 can be in fluid communication with the wound 406 at the tissue site 402 through at least one or more fluid channels 228 of the first film layer 204.

[0132] Figure 7C A wound sensor 504 is shown disposed within one of the plurality of windows 238 of the manifold 206. When the dressing 110 is disposed at the tissue site 402, the wound sensor 504 may be in fluid communication with the wound 406 at the tissue site 402 through at least one or more fluid channels 228 of the first membrane layer 204.

[0133] Fig.7D The wound sensor 504 is shown disposed between the manifold 206 and the second film layer 208. A portion of the manifold 206 can be recessed between the plurality of legs 240 of the manifold 206 such that the first surface 702 of the wound sensor 504 is flush with the first surface 232 of the manifold 206. When the dressing 110 is disposed at the tissue site 402, the wound sensor 504 can be in fluid contact with the wound 406 at the tissue site 402 through the manifold 206 and one or more fluid channels 228 of the first film layer 204.

[0134] Fig. 7EThe wound sensor 504 is shown disposed between the manifold 206 and the second membrane layer 208. A portion of the manifold 206 may be recessed between the plurality of legs 240 of the manifold 206 such that a first surface 702 of the wound sensor 504 is flush with the first surface 232 of the manifold 206. The dressing 110 may also include a sealing material 704 disposed around the wound sensor 504 to fluidically isolate the wound sensor 504 from the wound 406. In some embodiments, the wound sensor 504 may have an edge 706 that may couple the first surface 702 of the wound sensor 504 to the second surface 710 of the wound sensor 504. The edge 706 and the second surface 710 of the wound sensor 504 may be coupled to the sealing material. The first surface 702 of the wound sensor 504 may be coupled to the second membrane layer 208 to fluidically isolate the wound sensor 504 from both the surrounding environment and the wound 406.

[0135] Figure 7F The wound sensor 504 is shown coupled to the first surface 250 of the second membrane layer 208 opposite one of the plurality of windows 238 of the manifold 206. A portion 712 of the second membrane layer 208 can be disposed within one of the plurality of windows 238 of the manifold 206 such that the first surface 702 of the wound sensor 504 is flush with the first surface 250 of the second membrane layer 208. In some embodiments, the wound sensor 504 can be isolated from the wound 406 of the tissue site 402 to provide a baseline or atmospheric oxygen level reading when the wound sensor 504 is acted upon by a light source. In some embodiments, multiple wound sensors 504 can be used so that parameters can be measured at multiple locations using the wound sensor 504.

[0136] Fig. 8A and Figure 8B A portion of an alternative embodiment of a dressing 110 that can be used for deeper wounds is shown. In some cases, a wound may have contours or deeper areas that require a modified dressing that includes a rolling membrane 802. Fig. 8A and Figure 8B As shown, the rolling diaphragm 802 may include a first membrane layer 204 and a manifold 206. In other embodiments, the rolling diaphragm 802 may also include a second membrane layer 208. The wound sensor 504 may be disposed on the first surface 232 of the manifold and may be in fluid contact with the wound 406 at the tissue site 402 through the manifold 206 and one or more fluid channels 228 of the first membrane layer 204. Figure 8BAs shown, in some embodiments, the rolling diaphragm 802 can extend across the second surface 224 of the first film layer 204. The rolling diaphragm 802 can allow the dressing 110 to extend into a deeper wound so that the wound sensor 504 can be in closer contact with the deeper area of ​​the wound. In some embodiments, the dressing 110 can be manufactured so that the rolling diaphragms 802 are spaced apart along the dressing 110 so that the wound sensor 504 can be disposed at different depths within a wound being treated with the dressing 110.

[0137] Fig. 9 An example of a sensor 900 that may be used with any of the aforementioned embodiments of the dressing 110 is shown. It may be desirable to monitor multiple parameters at a tissue site with one sensor. In some embodiments, the sensor 900 may include a fluid sensor 902, an oxygen sensor 904, and a pH sensor 906. In other embodiments, the sensor 900 may monitor fewer or additional parameters. In some embodiments, there may be a liquid barrier 908 that may be disposed around the oxygen sensor 904 and the pH sensor 906 of the sensor 900. The liquid barrier 908 may prevent any liquid from the wound from directly contacting the oxygen sensor 904 and the pH sensor 906, but allow liquid to directly contact the fluid sensor 902. In some embodiments, the oxygen sensor 904 and the pH sensor 906 may be configured to change color when acted upon by a light source to indicate oxygen level and pH level, respectively. In some embodiments, the intensity of the emitted light may depend on the value of the sensed parameter, as described above with reference to Figure 2 As discussed. Fluid sensor 902 may be configured to detect the presence of fluid. Fluid sensor 902 may be partially or completely opaque when dry, and may be transparent when exposed to fluid, such that when sensor 220 transitions from opaque to transparent, sensor 220 has detected the presence of fluid. Sensor 900 may be configured in a peri-wound region or a wound contact region of a dressing. In some embodiments, sensor 900 may be disposed across both the peri-wound region and the wound contact region, such that fluid sensor 902 may be immersed in the presence of fluid in the peri-wound region, oxygen sensor 904 and pH sensor 906 are configured to detect the levels of oxygen and pH at a wound at a tissue site.

[0138] Fig.10An exemplary embodiment of the treatment system 100 deployed at a tissue site 402 is shown, wherein a light source 1002 is irradiated on a dressing 110. The light source 1002 may emit light 1004 toward the dressing 110. The light 1004 may penetrate the cover 125 of the dressing 110 to reach the periwound sensor 502 and the wound sensor 504. Once the light 1004 reaches the periwound sensor 502 and the wound sensor 504, the periwound sensor 502 and the wound sensor 504 may change color. The color of the periwound sensor 502 and the wound sensor 504 corresponds to the value of the sensed parameter at which they are located. For example, if the sensed parameter is oxygen level, the periwound sensor 502 and the wound sensor 504 may change color corresponding to their respective sensed oxygen levels. The periwound sensor 502 may be a first color 1006 that may indicate a first oxygen level, and the wound sensor 504 may be a second color 1008 that may indicate a second oxygen level. The second color 1008 from the wound sensor 504 may be stronger or more vivid than the first color 1006 , which may indicate that the wound sensor 504 is sensing lower oxygen levels than the peri-wound sensor 502 .

[0139] In some embodiments not shown herein, a UV-sensitive CCD camera may be placed above the dressing 110 opposite the tissue site 402 to capture the intensity of light emitted from the peri-wound sensor 502 and the wound sensor 504. In some embodiments not shown herein, the light source 1002 may include an excitation filter that may focus and filter out certain wavelengths of light so that only certain wavelengths reach the peri-wound sensor 502 and the wound sensor 504 of the dressing 110. Similarly, in some embodiments, the UV-sensitive CCD camera may include an emission filter to filter and focus light emitted by the peri-wound sensor 502 and the wound sensor 504.

[0140] Also described herein is a method of treating a tissue site 402 using negative pressure. The method may include placing a dressing 110 on the tissue site 402, applying negative pressure to the dressing 110 from a negative pressure source 105, and monitoring the dressing 110 for changes in a sensed parameter at the tissue site 402. The dressing 110 may include a cover 125, a wound contact layer 202, a manifold 206, and at least one sensor, such as a sensor 220, a periwound sensor 502, or a wound sensor 504. The cover 125 may include a first surface 262 and a second surface 264. The wound contact layer 202 may include a first surface 210 and a second surface 212. The second surface 212 of the wound contact layer 202 may be configured to contact the tissue site 402. The manifold 206 may include a first surface 232 and a second surface 234. The manifold 206 may be configured to be disposed between the second surface 264 of the cover 125 and the first surface 210 of the wound contact layer 202. The at least one sensor may include a plurality of parameter sensing molecules dissolved in a polymer matrix. The at least one sensor may be configured to indicate a sensed parameter when the at least one sensor is acted upon by the light source 1002 .

[0141] In some exemplary embodiments, monitoring the dressing for changes in a sensed parameter at the tissue site 402 may include detecting a color change in the at least one sensor when the at least one sensor is acted upon by a light source. In some exemplary embodiments, the sensed parameter may include at least one of a fluid level, an oxygen level, and a pH.

[0142] The systems, devices, and methods described herein may provide significant advantages. For example, the dressing 110 may be transparent, which may allow a clinician to easily monitor the tissue site 402 without interfering with the dressing 110. Sensors such as the sensor 220, the periwound sensor 502, and the wound sensor 504 may all help the clinician monitor changes in parameters of the tissue site 402, such as oxygen levels, pH levels, and fluid detection. These sensors may make the dressing smarter because they are able to communicate more information about the tissue site 402 without the need to integrate any electronic components into the dressing 110.

[0143] Although shown in several exemplary embodiments, it will be appreciated by those skilled in the art that the systems, apparatuses, and methods described herein are susceptible to various changes and modifications, and that these changes and modifications fall within the scope of the appended claims. In addition, unless the context clearly requires otherwise, descriptions of various alternatives using terms such as "or" do not need to be mutually exclusive, and unless the context clearly requires otherwise, the indefinite article "a" or "an" does not limit the subject matter to a single instance. For the purpose of sale, manufacture, assembly, or use, components may also be combined or removed in various configurations. For example, in some configurations, the dressing 110, the container 115, or both may be removed or separated from other components for manufacture or sale. In other exemplary configurations, the controller 130 may also be manufactured, configured, assembled, or sold independently of the other components.

[0144] The appended claims set forth novel and inventive aspects of the subject matter described above, but the claims may also include additional subject matter not specifically described in detail. For example, certain features, elements, or aspects may be omitted from the claims if it is not necessary to distinguish novel and inventive features from features known to those of 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 that serve the same, equivalent, or similar purposes without departing from the scope of the invention as defined by the appended claims.

Claims

1. A dressing for treating a tissue site using negative pressure, the dressing comprising: a cover, the cover comprising a first surface and a second surface; a wound contact layer comprising a first surface, a second surface, and a central hole, the second surface of the wound contact layer being configured to contact a peri-wound area of ​​the tissue site; a first film layer, the first film layer comprising a first surface and a second surface, the second surface of the first film layer being configured to contact a wound at the tissue site; and a manifold comprising a first surface and a second surface, the manifold being configured to be disposed between the second surface of the cover and the first surface of the first film layer; and The wound contact layer further comprises at least one sensor comprising a plurality of oxygen sensing molecules dissolved in a polymer matrix and configured to change color to indicate a sensed oxygen level when the at least one sensor is acted upon by a light source.

2. A dressing according to claim 1, wherein the wound contact layer further comprises a peripheral portion surrounding the central hole, the peripheral portion comprising a plurality of holes.

3. A dressing according to claim 2, wherein the at least one sensor is disposed within one of the plurality of holes in the wound contact layer.

4. A dressing according to claim 2, wherein the at least one sensor is disposed between the first surface of the wound contact layer and the second surface of the cover, the at least one sensor being adjacent to at least one hole of the plurality of holes of the wound contact layer.

5. The dressing of claim 2, wherein the at least one sensor is disposed between the first surface of the wound contact layer and the second surface of the cover, the at least one sensor being offset from the plurality of apertures of the wound contact layer.

6. The dressing of claim 1, wherein the at least one sensor comprises an oxygen sensing membrane.

7. The dressing of claim 6, wherein the oxygen sensing membrane comprises a low oxygen permeability polymer or a high oxygen permeability polymer.

8. The dressing of claim 7, wherein the low oxygen permeability polymer comprises one of polyvinyl alcohol, ethylene vinyl alcohol, polyacrylonitrile, and polyvinylidene chloride.

9. The dressing of claim 7, wherein the high oxygen permeability polymer comprises one of silicone and a polyolefin elastomer.

10. The dressing of claim 1, wherein the at least one sensor comprises a multi-sensor configured to detect fluid level, oxygen level, and pH level.

11. A dressing for treating a tissue site using negative pressure, the dressing comprising: a cover, the cover comprising a first surface and a second surface; a wound contact layer comprising a first surface, a second surface, a peripheral portion having a plurality of apertures, and a central aperture, the second surface of the wound contact layer being configured to contact a peri-wound region of the tissue site; a first film layer, the first film layer comprising a first surface and a second surface, the second surface of the first film layer being configured to contact a wound at the tissue site; and a manifold comprising a first surface and a second surface, the manifold being configured to be disposed between the second surface of the cover and the first surface of the first film layer; The cover also includes at least one sensor comprising a plurality of oxygen sensing molecules dissolved in a polymer matrix and configured to change color to indicate a sensed oxygen level when the at least one sensor is acted upon by a light source.

12. A dressing according to claim 11, wherein the at least one sensor is disposed within a recess in the first surface of the cover such that the at least one sensor is aligned with one of the plurality of apertures of the wound contact layer.

13. The dressing of claim 12, further comprising a recess cover removably coupled to the first surface of the cover, the recess cover being configured to seal the at least one sensor within the recess in the first surface of the cover.

14. The dressing of claim 11, wherein the at least one sensor is disposed on the first surface of the cover such that the sensor is aligned with one of the plurality of apertures of the wound contact layer.

15. The dressing of claim 11, wherein the cover further comprises a central portion having a central aperture and a peripheral portion, the peripheral portion of the cover being configured to couple to the peripheral portion of the wound contact layer.

16. A dressing according to claim 15, wherein the covering further includes a second film layer having a first surface and a second surface, the second film layer is configured to be substantially aligned with the central hole of the covering, and the second surface of the second film layer is configured to be connected to the first surface of the manifold.

17. A dressing according to claim 16, wherein the at least one sensor is disposed within a recess in the first surface of the second film layer.

18. The dressing of claim 17, further comprising a recess cover removably coupled to the first surface of the second film layer, the recess cover being configured to seal the at least one sensor within the recess in the first surface of the second film layer.

19. The dressing of claim 16, wherein the at least one sensor is disposed between a first surface of the manifold and a second surface of the second membrane layer.

20. The dressing of claim 16, further comprising at least one sealed cavity between the first surface of the manifold and the second surface of the second membrane layer, the at least one sensor being disposed within the at least one sealed cavity.

21. A dressing for treating a tissue site using negative pressure, the dressing comprising: a cover, the cover comprising a first surface and a second surface; a wound contact layer comprising a first surface, a second surface, a peripheral portion having a plurality of apertures, and a central aperture, the second surface of the wound contact layer being configured to contact a peri-wound region of the tissue site; a first film layer, the first film layer comprising a first surface and a second surface, the second surface of the first film layer being configured to contact a wound at the tissue site; a manifold comprising a first surface and a second surface, the manifold being configured to be disposed between the second surface of the cover and the first surface of the first film layer; and At least one sensor is recessed into the second surface of the first film layer, the at least one sensor comprising a plurality of oxygen sensing molecules dissolved in a polymer matrix and configured to change color to indicate a sensed oxygen level when the at least one sensor is acted upon by a light source.

22. A dressing for treating a tissue site using negative pressure, the dressing comprising: a cover, the cover comprising a first surface and a second surface; a wound contact layer comprising a first surface, a second surface, a peripheral portion having a plurality of apertures, and a central aperture, the second surface of the wound contact layer being configured to contact a peri-wound region of the tissue site; a first film layer, the first film layer comprising a first surface and a second surface, the second surface of the first film layer being configured to contact a wound at the tissue site; a manifold comprising a first surface and a second surface, the manifold being configured to be disposed between the second surface of the cover and the first surface of the first film layer; and At least one sensor is disposed between the second surface of the manifold and the first surface of the first membrane layer, the at least one sensor comprising a plurality of oxygen sensing molecules dissolved in a polymer matrix and configured to change color to indicate a sensed oxygen level when the at least one sensor is acted upon by a light source.

23. The dressing of claim 22, wherein the at least one sensor is positioned proximate to a window of the manifold such that the at least one sensor is visible through the window of the manifold.

24. A method of treating a tissue site using negative pressure, the method comprising: A dressing is disposed on the tissue site, the dressing comprising: a cover, the cover comprising a first surface and a second surface; a wound contact layer comprising a first surface and a second surface, the second surface of the wound contact layer being configured to contact the tissue site; a manifold comprising a first surface and a second surface, the manifold being configured to be disposed between the second surface of the cover and the first surface of the wound contact layer; and at least one sensor, the at least one sensor comprising a plurality of parameter sensing molecules dissolved in a polymer matrix, the at least one sensor configured to indicate a sensed parameter when the at least one sensor is acted upon by a light source; applying negative pressure to the dressing from a negative pressure source; and The dressing is monitored for changes in the sensed parameter at the tissue site.

25. The method of claim 24, wherein monitoring the dressing for changes in the sensed parameter at the tissue site comprises detecting a color change in the at least one sensor when the at least one sensor is acted upon by the light source.

26. The method of claim 24, wherein the sensed parameter comprises at least one of fluid level, oxygen level, and pH.

27. A wound contact layer for treating a tissue site, the wound contact layer comprising: Central part; a peripheral portion surrounding the central portion, the peripheral portion having a plurality of apertures; and At least one sensor includes a plurality of oxygen sensing molecules dissolved in a polymer matrix, the at least one sensor being integrated into the peripheral portion separately from each of the plurality of apertures and configured to change color in response to a light source to indicate a sensed oxygen level.

28. Systems, apparatus and methods substantially as described herein.

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