Low profile instillation and negative-pressure bridge

Disclosed embodiments relate to devices and systems for providing both negative-pressure therapy and instillation, In some embodiments, both negative-pressure and instillation may be provided to a tissue site in a low-profile context that may also prevent siphoning of instillation fluid during negative pressure application. For example, a single bridge may include a negative-pressure pathway with supports and an instillation pathway, and the instillation pathway may be configured with respect to the negative-pressure pathway so that at least a portion of the instillation pathway collapses upon application of negative pressure to the negative-pressure pathway. Collapse of at least a portion of the instillation pathway may be sufficient to close the instillation pathway.

TECHNICAL FIELD

The invention set forth in the appended claims relates generally to tissue treatment systems and more particularly, but without limitation, to low-profile distribution components for providing negative-pressure therapy and/or instillation.

BACKGROUND

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

There is also widespread acceptance that cleansing a tissue site can be highly beneficial for new tissue growth. For example, a wound or a cavity can be washed out with a liquid solution for therapeutic purposes. These practices are commonly referred to as “irrigation” and “lavage” respectively. “Instillation” is another practice that generally refers to a process of slowly introducing fluid to a tissue site and leaving the fluid for a prescribed period of time before removing the fluid. For example, instillation of topical treatment solutions over a wound bed can be combined with negative-pressure therapy to further promote wound healing by loosening soluble contaminants in a wound bed and removing infectious material. As a result, soluble bacterial burden can be decreased, contaminants removed, and the wound cleansed.

While the clinical benefits of negative-pressure therapy and/or instillation therapy are widely known, improvements to therapy systems, components, and processes may benefit healthcare providers and patients.

BRIEF SUMMARY

New and useful systems, apparatuses, and methods for treating tissue in a negative-pressure therapy environment are set forth in the appended claims. Illustrative embodiments are also provided to enable a person skilled in the art to make and use the claimed subject matter. Some embodiments are illustrative of an apparatus or system for delivering both negative pressure and instillation to a tissue site, which can be used in conjunction with low-profile distribution components.

For example, in some embodiments, a low-profile bridge may be configured to allow application of negative pressure and instillation fluid alternately, through separate pathways. The configuration may maintain an open pathway for the application of both negative pressure and instillation fluid, which does not occlude even if a compressive load is applied to the bridge. Further, the configuration may prevent unintended siphoning of the instillation fluid during negative-pressure therapy. For example, a single bridge may include two separate pathways: a negative-pressure pathway and an instillation pathway. In some embodiments, the instillation pathway may be a collapsible conduit located within the negative-pressure pathway. For example, the instillation pathway may comprise a thin polyurethane tube. The negative-pressure pathway may include open pathway features, configured to maintain an open pathway in the negative-pressure pathway. For example, the open pathway features may be thermoformed structures, which may include a plurality of supports configured to prevent collapse of the negative-pressure pathway in some embodiments. In some embodiments, the negative-pressure pathway may locate these thermoformed structures within a barrier film shell that is sealed to provide an enclosed pathway for negative pressure. The supports of the negative-pressure pathway may contact the collapsible instillation conduit in some embodiments. For example, the negative-pressure pathway may comprise two stacked thermoformed structures, with supports from each thermoformed structure projecting into the enclosed space of the negative-pressure pathway from opposite directions, and in some embodiments the collapsible instillation conduit may be located between opposing supports in the negative-pressure pathway. In some embodiments, the instillation pathway and the negative-pressure pathway may be in fluid communication through their distal ends. For example, application of negative pressure to the negative-pressure pathway may collapse the instillation pathway, preventing or restricting fluid flow through the instillation pathway in order to prevent or reduce unintended siphoning of instillation fluid through the instillation pathway during negative-pressure wound therapy.

In some alternate embodiments, the instillation pathway may be located in a separate bridge from the negative-pressure pathway. For example, the instillation bridge may comprise open pathway features, such as instillation supports, to prevent collapse of the instillation pathway, but may have an unsupported section or gap which is configured to collapse upon experiencing negative pressure. The unsupported gap may be configured to be forced open during fluid delivery through the instillation pathway, but to close or clamp shut during fluid removal though the separate negative-pressure bridge. For example, the negative-pressure pathway may be located in a first low-profile bridge, while the instillation pathway may be located in a separate, second low-profile bridge. The instillation bridge and the negative-pressure bridge may be in fluid communication, so that during negative-pressure therapy through the negative-pressure pathway, the instillation pathway also experiences negative pressure. Applying negative pressure to the instillation pathway may act upon the gap to close the instillation pathway during negative-pressure wound therapy. The separate negative-pressure and instillation bridges may operate together as a system configured to provide negative-pressure therapy and/or instillation.

More generally, some embodiments may relate to managing fluid at a tissue site, and may comprise a negative-pressure pathway comprising a plurality of supports configured to support the negative-pressure pathway; and an instillation pathway configured to interact with the negative-pressure pathway so that at least a portion of the instillation pathway collapses upon application of negative pressure to the negative-pressure pathway. In some embodiments, the plurality of supports may be configured to maintain the negative-pressure pathway as an open pathway when the negative-pressure pathway is under compression. In some embodiments, the negative-pressure pathway and the instillation pathway may be pneumatically isolated from each other and the ambient environment except through an aperture and/or recessed space in a distal end of the apparatus. Collapse of the instillation pathway may be sufficient to close the instillation pathway, substantially preventing fluid flow through the instillation pathway in some embodiments. For example, the instillation pathway may comprise a collapsible conduit configured to interact with the negative-pressure pathway so that the collapsible conduit collapses along its length upon application of negative pressure to the negative-pressure pathway. In some embodiments, the instillation pathway comprises no internal support. In some embodiments, the negative-pressure pathway and/or instillation pathway may be configured to fluidly communicate with the ambient environment through the aperture, for example allowing instillation fluid and/or negative pressure to be applied to a tissue site. In some embodiments, the instillation pathway may be configured to interact with the plurality of supports of the negative-pressure pathway to maintain an open pathway for instillation when the instillation pathway is under compression.

In some embodiments, the plurality of supports may be co-extensive with the negative-pressure pathway. The instillation pathway and the negative-pressure pathway may be located within a single bridge, in some embodiments. For example, the instillation pathway may be located within the negative-pressure pathway and may extend lengthwise substantially for the length of the negative-pressure pathway. In some embodiments, the plurality of supports may be formed in one or more spacer layers. For example, the negative-pressure pathway may comprise two spacer layers, each having supports extending inward into the enclosed space of the negative-pressure pathway, and the instillation pathway may be located between the spacer layers. In some embodiments, the apparatus may be configured with a low profile.

In some embodiments, the negative-pressure pathway may comprise a first layer, which can be coupled to the instillation pathway to form the enclosed space of the negative-pressure pathway. For example, the first layer may be sealed about a perimeter to the instillation pathway, so that the instillation pathway and the first layer jointly form the enclosed space of the negative-pressure pathway. In some embodiments, the supports may be located in the enclosed space of the negative-pressure pathway, between the first layer and the instillation pathway. For example, the supports may extend from the first layer towards and/or contacting the instillation pathway. In some embodiments, the instillation pathway may be in stacked relationship with the negative-pressure pathway.

In some embodiments, the instillation pathway may be located in a separate bridge from the negative-pressure pathway. The instillation pathway may comprise a plurality of instillation supports configured to support the instillation pathway, and a gap between the plurality of supports configured to allow collapse across the width of the instillation pathway upon application of negative pressure. For example, the gap may not include any instillation supports. In some embodiments, the plurality of instillation supports may be co-extensive with the instillation pathway, except for the gap.

Some embodiments may relate to an apparatus for distributing liquid to a tissue site, and the apparatus may comprise an instillation pathway that is pneumatically isolated from the ambient environment except through an instillation aperture in a distal end; a plurality of instillation supports within the instillation pathway configured to support the instillation pathway; and a gap between the plurality of supports configured to allow collapse across the width of the instillation pathway upon application of negative pressure. In some embodiments, the gap may not have any instillation supports; and collapse of the instillation pathway may be sufficient to close the instillation pathway, substantially preventing fluid flow through the instillation pathway. The plurality of instillation supports may be co-extensive with the instillation pathway, except for the gap. In some embodiments, the apparatus may be configured with a low profile. For example, the apparatus may be an instillation bridge.

A system for distributing negative pressure and instillation fluid to a tissue site is also described herein, wherein some example embodiments include a negative-pressure pathway; an instillation pathway that is pneumatically isolated from the ambient environment and from the negative-pressure pathway except through an instillation aperture in a distal end; a plurality of instillation supports within the instillation pathway that are configured to support the instillation pathway; and a gap between the plurality of instillation supports configured to allow collapse across the width of the instillation pathway upon application of negative pressure. Typically, the instillation pathway may be configured to interact with the negative-pressure pathway so that, upon application of negative pressure to the negative-pressure pathway, the gap collapses. For example, collapse of the instillation pathway may be sufficient to close the instillation pathway, substantially preventing fluid flow through the instillation pathway. In some embodiments, the plurality of instillation supports may be co-extensive with the instillation pathway, except for the gap. In some embodiments, the plurality of instillation supports may be arranged in rows, with the rows aligned. The instillation pathway may be located in a separate bridge from the negative-pressure pathway, in some embodiments. For example, each of the instillation pathway bridge and the negative-pressure pathway bridge may be configured with a low profile.

Still other exemplary embodiments relate to an apparatus for managing fluid at a tissue site, and the apparatus may comprise a negative-pressure pathway; and an instillation pathway configured to maintain an open fluid pathway when fluid is applied therethrough, and configured to interact with the negative-pressure pathway so that, upon application of negative pressure to the negative-pressure pathway, at least a portion of the instillation pathway collapses. In some embodiments, the instillation pathway is pneumatically isolated from the ambient environment and from the negative-pressure pathway except through an aperture in a distal end. Collapse of at least a portion of the instillation pathway may be sufficient to close the instillation pathway, substantially preventing fluid flow through the instillation pathway.

In some embodiments, the instillation pathway may be located in a separate bridge from the negative-pressure pathway. The instillation pathway may comprise a plurality of instillation supports configured to support the instillation pathway, and a gap between the plurality of instillation supports configured to allow collapse across the width of the instillation pathway upon application of negative pressure. For example, except for the unsupported gap, the plurality of instillation supports may be fully co-extensive with the instillation pathway.

In some embodiments, the instillation pathway and the negative-pressure pathway may both be located in a single bridge. The negative-pressure pathway may comprise a plurality of supports configured to support the negative-pressure pathway to prevent the negative-pressure pathway from collapsing. In some embodiments, the instillation pathway may be located within the negative-pressure pathway. The instillation pathway may comprise a collapsible conduit configured to be collapsible along its entire length. For example, the instillation pathway may have no internal support.

Objectives, advantages, and a preferred mode of making and using the claimed subject matter may be understood best by reference to the accompanying drawings in conjunction with the following detailed description of illustrative embodiments.

DESCRIPTION OF EXAMPLE EMBODIMENTS

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

The example embodiments may also be described herein with reference to spatial relationships between various elements or to the spatial orientation of various elements depicted in the attached drawings. In general, such relationships or orientation assume a frame of reference consistent with or relative to a patient in a position to receive treatment. However, as should be recognized by those skilled in the art, this frame of reference is merely a descriptive expedient rather than a strict prescription.

FIG.1is a simplified functional block diagram of an example embodiment of a therapy system100that can provide negative-pressure therapy with instillation of topical treatment solutions to a tissue site in accordance with this specification.

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

The therapy system100may include a source or supply of negative pressure, such as a negative-pressure source105, and one or more distribution components. A distribution component is preferably detachable and may be disposable, reusable, or recyclable. A dressing, such as a dressing110, and a fluid container, such as a container115, are examples of distribution components that may be associated with some examples of the therapy system100. As illustrated in the example ofFIG.1, the dressing110may comprise or consist essentially of a tissue interface120, a cover125, or both in some embodiments.

A fluid conductor is another illustrative example of a distribution component. A “fluid conductor,” in this context, broadly includes a tube, pipe, hose, conduit, or other structure with one or more lumina or open pathways adapted to convey a fluid between two ends. A tube, for example, is generally an elongated, flexible structure with a cylindrical lumen, but the geometry and rigidity may vary. Moreover, some fluid conductors may be molded into or otherwise integrally combined with other components. Distribution components may also include or comprise interfaces or fluid ports to facilitate coupling and de-coupling other components. In some embodiments, for example, a dressing interface may facilitate coupling a fluid conductor to the dressing110. For example, such a dressing interface may be a SENSAT.R.A.C.™ Pad, available from Kinetic Concepts, Inc. of San Antonio, Texas.

The therapy system100may also include a regulator or controller, such as a controller130. Additionally, the therapy system100may include sensors to measure operating parameters and provide feedback signals to the controller130indicative of the operating parameters. As illustrated inFIG.1, for example, the therapy system100may include a first sensor135and a second sensor140coupled to the controller130.

The therapy system100may also include a source of instillation solution. For example, a solution source145may be fluidly coupled to the dressing110, as illustrated in the example embodiment ofFIG.1. The solution source145may be fluidly coupled to a positive-pressure source, such as a positive-pressure source150, a negative-pressure source, such as the negative-pressure source105, or both in some embodiments. A regulator, such as an instillation regulator155, may also be fluidly coupled to the solution source145and the dressing110to ensure proper dosage of instillation solution (e.g. saline) to a tissue site. For example, the instillation regulator155may comprise a piston that can be pneumatically actuated by the negative-pressure source105to draw instillation solution from the solution source during a negative-pressure interval and to instill the solution to a dressing during a venting interval. Additionally or alternatively, the controller130may be coupled to the negative-pressure source105, the positive-pressure source150, or both, to control dosage of instillation solution to a tissue site. In some embodiments, the instillation regulator155may also be fluidly coupled to the negative-pressure source105through the dressing110, as illustrated in the example ofFIG.1.

In some examples, a bridge160may fluidly couple the dressing110to the negative-pressure source105, as illustrated inFIG.1. The therapy system100may also comprise a flow regulator, such as a regulator165, fluidly coupled to a source of ambient air to provide a controlled or managed flow of ambient air. In some embodiments, the regulator165may be fluidly coupled to the tissue interface120through the bridge160. In some embodiments, the regulator165may be positioned proximate to the container115and/or proximate a source of ambient air, where the regulator165is less likely to be blocked during usage.

Some components of the therapy system100may be housed within or used in conjunction with other components, such as sensors, processing units, alarm indicators, memory, databases, software, display devices, or user interfaces that further facilitate therapy. For example, in some embodiments, the negative-pressure source105may be combined with the controller130, the solution source145, and other components into a therapy unit.

In general, components of the therapy system100may be coupled directly or indirectly. For example, the negative-pressure source105may be directly coupled to the container115and may be indirectly coupled to the dressing110through the container115. Coupling may include fluid, mechanical, thermal, electrical, or chemical coupling (such as a chemical bond), or some combination of coupling in some contexts. For example, the negative-pressure source105may be electrically coupled to the controller130and may be fluidly coupled to one or more distribution components to provide a fluid path to a tissue site. In some embodiments, components may also be coupled by virtue of physical proximity, being integral to a single structure, or being formed from the same piece of material.

A negative-pressure supply, such as the negative-pressure source105, may be a reservoir of air at a negative pressure or may be a manual or electrically-powered device, such as a vacuum pump, a suction pump, a wall suction port available at many healthcare facilities, or a micro-pump, for example. “Negative pressure” generally refers to a pressure less than a local ambient pressure, such as the ambient pressure in a local environment external to a sealed therapeutic environment. In many cases, the local ambient pressure may also be the atmospheric pressure at which a tissue site is located. Alternatively, the pressure may be less than a hydrostatic pressure associated with tissue at the tissue site. Unless otherwise indicated, values of pressure stated herein are gauge pressures. References to increases in negative pressure typically refer to a decrease in absolute pressure, while decreases in negative pressure typically refer to an increase in absolute pressure. While the amount and nature of negative pressure provided by the negative-pressure source105may vary according to therapeutic requirements, the pressure is generally a low vacuum, also commonly referred to as a rough vacuum, between −5 mm Hg (−667 Pa) and −500 mm Hg (−66.7 kPa). Common therapeutic ranges are between −50 mm Hg (−6.7 kPa) and −300 mm Hg (−39.9 kPa).

The container115is representative of a container, canister, pouch, or other storage component, which can be used to manage exudates and other fluids withdrawn from a tissue site. In many environments, a rigid container may be preferred or required for collecting, storing, and disposing of fluids. In other environments, fluids may be properly disposed of without rigid container storage, and a re-usable container could reduce waste and costs associated with negative-pressure therapy.

A controller, such as the controller130, may be a microprocessor or computer programmed to operate one or more components of the therapy system100, such as the negative-pressure source105. In some embodiments, for example, the controller130may be a microcontroller, which generally comprises an integrated circuit containing a processor core and a memory programmed to directly or indirectly control one or more operating parameters of the therapy system100. Operating parameters may include the power applied to the negative-pressure source105, the pressure generated by the negative-pressure source105, or the pressure distributed to the tissue interface120, for example. The controller130is also preferably configured to receive one or more input signals, such as a feedback signal, and programmed to modify one or more operating parameters based on the input signals.

Sensors, such as the first sensor135and the second sensor140, are generally known in the art as any apparatus operable to detect or measure a physical phenomenon or property, and generally provide a signal indicative of the phenomenon or property that is detected or measured. For example, the first sensor135and the second sensor140may be configured to measure one or more operating parameters of the therapy system100. In some embodiments, the first sensor135may be a transducer configured to measure pressure in a pneumatic pathway and convert the measurement to a signal indicative of the pressure measured. In some embodiments, for example, the first sensor135may be a piezo-resistive strain gauge. The second sensor140may optionally measure operating parameters of the negative-pressure source105, such as a voltage or current, in some embodiments. Preferably, the signals from the first sensor135and the second sensor140are suitable as an input signal to the controller130, but some signal conditioning may be appropriate in some embodiments. For example, the signal may need to be filtered or amplified before it can be processed by the controller130. Typically, the signal is an electrical signal, but may be represented in other forms, such as an optical signal.

The tissue interface120can be generally adapted to partially or fully contact a tissue site. The tissue interface120may take many forms, and may have many sizes, shapes, or thicknesses, depending on a variety of factors, such as the type of treatment being implemented or the nature and size of a tissue site. For example, the size and shape of the tissue interface120may be adapted to the contours of deep and irregular shaped tissue sites. Any or all of the surfaces of the tissue interface120may have an uneven, coarse, or jagged profile.

In some embodiments, the tissue interface120may comprise or consist essentially of a manifold. A manifold in this context may comprise or consist essentially of a means for collecting or distributing fluid across the tissue interface120under pressure. For example, a manifold may be adapted to receive negative pressure from a source and distribute negative pressure through multiple apertures across the tissue interface120, which may have the effect of collecting fluid from across a tissue site and drawing the fluid toward the source. In some embodiments, the fluid path may be reversed or a secondary fluid path may be provided to facilitate delivering fluid, such as fluid from a source of instillation solution, across a tissue site.

In some illustrative embodiments, a manifold may comprise a plurality of pathways, which can be interconnected to improve distribution or collection of fluids. In some illustrative embodiments, a manifold may comprise or consist essentially of a porous material having interconnected fluid pathways. Examples of suitable porous material that can be adapted to form interconnected fluid pathways (e.g., channels) may include cellular foam, including open-cell foam such as reticulated foam; porous tissue collections; and other porous material such as gauze or felted mat that generally include pores, edges, and/or walls. Liquids, gels, and other foams may also include or be cured to include apertures and fluid pathways. In some embodiments, a manifold may additionally or alternatively comprise projections that form interconnected fluid pathways. For example, a manifold may be molded to provide surface projections that define interconnected fluid pathways.

In some embodiments, the tissue interface120may comprise or consist essentially of reticulated foam having pore sizes and free volume that may vary according to needs of a prescribed therapy. For example, reticulated foam having a free volume of at least 90% may be suitable for many therapy applications, and foam having an average pore size in a range of 400-600 microns (40-50 pores per inch) may be particularly suitable for some types of therapy. The tensile strength of the tissue interface120may also vary according to needs of a prescribed therapy. For example, the tensile strength of foam may be increased for instillation of topical treatment solutions. The 25% compression load deflection of the tissue interface120may be at least 0.35 pounds per square inch, and the 65% compression load deflection may be at least 0.43 pounds per square inch. In some embodiments, the tensile strength of the tissue interface120may be at least 10 pounds per square inch. The tissue interface120may have a tear strength of at least 2.5 pounds per inch. In some embodiments, the tissue interface may be foam comprised of polyols, such as polyester or polyether, isocyanate, such as toluene diisocyanate, and polymerization modifiers, such as amines and tin compounds. In some examples, the tissue interface120may be reticulated polyurethane foam such as found in GRANUFOAM™ dressing or V.A.C. VERAFLO™ dressing, both available from Kinetic Concepts, Inc. of San Antonio, Texas.

The thickness of the tissue interface120may also vary according to needs of a prescribed therapy. For example, the thickness of the tissue interface may be decreased to reduce tension on peripheral tissue. The thickness of the tissue interface120can also affect the conformability of the tissue interface120. In some embodiments, a thickness in a range of about 5 millimeters to 10 millimeters may be suitable.

The tissue interface120may be either hydrophobic or hydrophilic. In an example in which the tissue interface120may be hydrophilic, the tissue interface120may also wick fluid away from a tissue site, while continuing to distribute negative pressure to the tissue site. The wicking properties of the tissue interface120may draw fluid away from a tissue site by capillary flow or other wicking mechanisms. An example of a hydrophilic material that may be suitable is a polyvinyl alcohol, open-cell foam such as V.A.C. WHITEFOAM™ dressing available from Kinetic Concepts, Inc. of San Antonio, Texas Other hydrophilic foams may include those made from polyether. Other foams that may exhibit hydrophilic characteristics include hydrophobic foams that have been treated or coated to provide hydrophilicity.

In some embodiments, the tissue interface120may be constructed from bioresorbable materials. Suitable bioresorbable materials may include, without limitation, a polymeric blend of polylactic acid (PLA) and polyglycolic acid (PGA). The polymeric blend may also include, without limitation, polycarbonates, polyfumarates, and capralactones. The tissue interface120may further serve as a scaffold for new cell-growth, or a scaffold material may be used in conjunction with the tissue interface120to promote cell growth. A scaffold is generally a substance or structure used to enhance or promote the growth of cells or formation of tissue, 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 hydroxy apatites, carbonates, or processed allograft materials.

In some embodiments, the cover125may provide a bacterial barrier and protection from physical trauma. The cover125may also be constructed from a material that can reduce evaporative losses and provide a fluid seal between two components or two environments, such as between a therapeutic environment and a local external environment. The cover125may comprise or consist of, for example, an elastomeric film or membrane that can provide a seal adequate to maintain a negative pressure at a tissue site for a given negative-pressure source. The cover125may have a high moisture-vapor transmission rate (MVTR) in some applications. For example, the MVTR may be at least 250 grams per square meter per twenty-four hours in some embodiments, measured using an upright cup technique according to ASTM E96/E96M Upright Cup Method at 38° C. and 10% relative humidity (RH). In some embodiments, an MVTR up to 5,000 grams per square meter per twenty-four hours may provide effective breathability and mechanical properties.

In some example embodiments, the cover125may be a polymer drape, such as a polyurethane film, that is permeable to water vapor but impermeable to liquid. Such drapes typically have a thickness in the range of 25-50 microns. For permeable materials, the permeability generally should be low enough that a desired negative pressure may be maintained. The cover125may comprise, for example, one or more of the following materials: polyurethane (PU), such as hydrophilic polyurethane; cellulosics; hydrophilic polyamides; polyvinyl alcohol; polyvinyl pyrrolidone; hydrophilic acrylics; silicones, such as hydrophilic silicone elastomers; natural rubbers; polyisoprene; styrene butadiene rubber; chloroprene rubber; polybutadiene; nitrile rubber; butyl rubber; ethylene propylene rubber; ethylene propylene diene monomer; chlorosulfonated polyethylene; polysulfide rubber; ethylene vinyl acetate (EVA); co-polyester; and polyether block polymide copolymers. Such materials are commercially available as, for example, Tegaderm® drape, commercially available from 3M Company, Minneapolis Minnesota; polyurethane (PU) drape, commercially available from Avery Dennison Corporation, Pasadena, California; polyether block polyamide copolymer (PEBAX), for example, from Arkema S.A., Colombes, France; and Inspire 2301 and Inpsire 2327 polyurethane films, commercially available from Expopack Advanced Coatings, Wrexham, United Kingdom. In some embodiments, the cover125may comprise INSPIRE 2301 having an MVTR (upright cup technique) of 2600 g/m2/24 hours and a thickness of about 30 microns.

An attachment device may be used to attach the cover125to an attachment surface, such as undamaged epidermis, a gasket, or another cover. The attachment device may take many forms. For example, an attachment device may be a medically-acceptable, pressure-sensitive adhesive configured to bond the cover125to epidermis around a tissue site. In some embodiments, for example, some or all of the cover125may be coated with an adhesive, such as an acrylic adhesive, which may have a coating weight of about 25-65 grams per square meter (g.s.m.). Thicker adhesives, or combinations of adhesives, may be applied in some embodiments to improve the seal and reduce leaks. Other example embodiments of an attachment device may include a double-sided tape, paste, hydrocolloid, hydrogel, silicone gel, or organogel.

The solution source145may also be representative of a container, canister, pouch, bag, or other storage component, which can provide a solution for instillation therapy. Compositions of solutions may vary according to a prescribed therapy, but examples of solutions that may be suitable for some prescriptions include hypochlorite-based solutions, silver nitrate (0.5%), sulfur-based solutions, biguanides, cationic solutions, and isotonic solutions.

In operation, the tissue interface120may be placed within, over, on, or otherwise proximate to a tissue site. If the tissue site is a wound, for example, the tissue interface120may partially or completely fill the wound, or it may be placed over the wound. The cover125may be placed over the tissue interface120and sealed to an attachment surface near a tissue site. For example, the cover125may be sealed to undamaged epidermis peripheral to a tissue site. Thus, the dressing110can provide a sealed therapeutic environment proximate to a tissue site, substantially isolated from the external environment, and the negative-pressure source105can reduce pressure in the sealed therapeutic environment. In some embodiments, the regulator165may control the flow of ambient air to purge fluids and exudates from the sealed therapeutic environment.

The fluid mechanics of using a negative-pressure source to reduce pressure in another component or location, such as within a sealed therapeutic environment, can be mathematically complex. However, the basic principles of fluid mechanics applicable to negative-pressure therapy and instillation are generally well-known to those skilled in the art, and the process of reducing pressure may be described illustratively herein as “delivering,” “distributing,” or “generating” negative pressure, for example.

In general, exudate and other fluid flow toward lower pressure along a fluid path. Thus, the term “downstream” typically implies something in a fluid path relatively closer to a source of negative pressure or further away from a source of positive pressure. Conversely, the term “upstream” implies something relatively further away from a source of negative pressure or closer to a source of positive pressure. Similarly, it may be convenient to describe certain features in terms of fluid “inlet” or “outlet” in such a frame of reference. This orientation is generally presumed for purposes of describing various features and components herein. However, the fluid path may also be reversed in some applications, such as by substituting a positive-pressure source for a negative-pressure source, and this descriptive convention should not be construed as a limiting convention.

Negative pressure applied across the tissue site through the tissue interface120in the sealed therapeutic environment can induce macro-strain and micro-strain in the tissue site. Negative pressure can also remove exudate and other fluid from a tissue site, which can be collected in container115.

In some embodiments, the controller130may receive and process data from one or more sensors, such as the first sensor135. The controller130may also control the operation of one or more components of the therapy system100to manage the pressure delivered to the tissue interface120. In some embodiments, controller130may include an input for receiving a desired target pressure and may be programmed for processing data relating to the setting and inputting of the target pressure to be applied to the tissue interface120. In some example embodiments, the target pressure may be a fixed pressure value set by an operator as the target negative pressure desired for therapy at a tissue site and then provided as input to the controller130. The target pressure may vary from tissue site to tissue site based on the type of tissue forming a tissue site, the type of injury or wound (if any), the medical condition of the patient, and the preference of the attending physician. After selecting a desired target pressure, the controller130can operate the negative-pressure source105in 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 interface120.

In some embodiments, the controller130may have a continuous pressure mode, in which the negative-pressure source105is operated to provide a constant target negative pressure for the duration of treatment or until manually deactivated. Additionally or alternatively, the controller may have an intermittent pressure mode. For example, the controller130can operate the negative-pressure source105to cycle between a target pressure and atmospheric pressure. In some examples, the target pressure may be set at a value of 135 mmHg for a specified period of time (e.g., 5 min), followed by a specified period of time (e.g., 2 min) of deactivation. The cycle can be repeated by activating the negative-pressure source105, which can form a square wave pattern between the target pressure and atmospheric pressure.

In some example embodiments, the increase in negative pressure from ambient pressure to the target pressure may not be instantaneous. For example, the negative-pressure source105and the dressing110may have an initial rise time, which can vary depending on the type of dressing and therapy equipment being used. For example, the initial rise time for one therapy system may be in a range of about 20-30 mmHg/second and in a range of about 5-10 mmHg/second for another therapy system. If the therapy system100is operating in an intermittent mode, the repeating rise time may be a value substantially equal to the initial rise time.

In other examples, a target pressure can vary with time in a dynamic pressure mode. For example, the target pressure may vary in the form of a triangular waveform, varying between a negative pressure of 50 and 135 mmHg with a rise time set at a rate of +25 mmHg/min. and a descent time set at −25 mmHg/min. In other embodiments of the therapy system100, the triangular waveform may vary between negative pressure of 25 and 135 mmHg with a rise time set at a rate of +30 mmHg/min and a descent time set at −30 mmHg/min.

In some embodiments, the controller130may control or determine a variable target pressure in a dynamic pressure mode, and the variable target pressure may vary between a maximum and minimum pressure value that may be set as an input prescribed by an operator as the range of desired negative pressure. The variable target pressure may also be processed and controlled by the controller130, which can vary the target pressure according to a predetermined waveform, such as a triangular waveform, a sine waveform, or a saw-tooth waveform. In some embodiments, the waveform may be set by an operator as the predetermined or time-varying negative pressure desired for therapy.

FIG.2is a schematic diagram of an example embodiment of the therapy system100configured to apply negative pressure and treatment solutions to a tissue site205. Some components of the therapy system100may be housed within or used in conjunction with other components, such as processing units, alarm indicators, memory, databases, software, display devices, or user interfaces that further facilitate therapy. For example, in some embodiments, the negative-pressure source105may be combined with the controller130and other components into a therapy unit, such as a therapy unit210illustrated inFIG.2. The therapy unit210may be, for example, a V.A.C.ULTA™ Therapy Unit available from Kinetic Concepts, Inc. of San Antonio, Texas.

In the example ofFIG.2, the tissue site205is at least partially defined by a wound edge215, which extends through an epidermal layer220and a dermal layer225and reaches into a hypodermis, or subcutaneous tissue230. The therapy system100may be used to treat a wound of any depth, as well as many different types of wounds, including open wounds, incisions, or other tissue sites. Treatment of the tissue site205may include removal of fluids originating from the tissue site205, such as exudates or ascites, or fluids instilled into the dressing to cleanse or treat the tissue site205, such as antimicrobial solutions.

In the example ofFIG.2, a conduit235fluidly couples the container115to another fluid conductor, such as the bridge160, which provides a fluid pathway between the conduit235and the tissue interface120. The bridge160in the example ofFIG.2is a substantially flat and flexible fluid conductor, but can also be compressed without occluding or blocking the fluid pathway between the conduit235and the tissue interface120. In some embodiments, the bridge160may comprise or be coupled to an applicator240adapted to be positioned in fluid communication with the tissue interface120through an aperture in the cover125. The cover125may be sealed to the epidermal layer220with an attachment device, such as an adhesive layer245.

In some embodiments, the applicator240may be integral to the bridge160. In other embodiments, the applicator240and the bridge160may be separate components that are coupled together to form a single device. In yet other embodiments, the applicator240and the bridge160may be separate components that may be used independently of each other in the therapy system100.

The bridge160may have a substantially flat profile, and an adapter250may be configured to fluidly couple the bridge160to a tube or other round fluid conductor, such as the conduit235illustrated in the example ofFIG.2. In some embodiments, the adapter250may have one or more sealing valves, which can isolate the conduit235if separated from the bridge160.

The example ofFIG.2also illustrates a configuration of the therapy system100in which the solution source145is fluidly coupled to the tissue interface120through a conduit255and a dressing interface260.

FIG.3Ais a segmented perspective bottom view of an example of the bridge160, illustrating additional details that may be associated with some embodiments. The bridge160ofFIG.3Agenerally has a low profile structure.FIG.3Afurther illustrates features that may be associated with some embodiments of the applicator240ofFIG.2. The applicator240may be bulbous or any shape suitable for facilitating a connection to the dressing110. The bridge160in the example ofFIG.3Ais generally long and narrow. An adapter, such as the adapter250, may fluidly couple the bridge160to a fluid conductor, such as the conduit235. In some examples, the conduit235may be a multi-lumen tube in which a central lumen305is configured to couple the bridge160to a negative-pressure source, and one or more peripheral lumens310are configured to couple the bridge160to a sensor, such as the first sensor135.

In some embodiments, the bridge160may comprise a liquid barrier formed from two layers. InFIG.3A, for example, a periphery of a first layer315may be coupled to a second layer320to form a fluid path between two ends of the bridge160, including the applicator240. The first layer315and the second layer320may both be formed from or include a polymeric film of liquid-impermeable material. In some examples, the first layer315, the second layer320, or both may be formed from the same material as the cover125. The first layer315and the second layer320may be coupled around the periphery of the bridge160to form the sealed space by welding (RF or ultrasonic), heat sealing, or adhesive bonding, such as acrylics or cured adhesives. For example, the first layer315and the second layer320may be welded together around the periphery of the bridge160and may form a flange325around the periphery of the bridge160as a result of the weld.

The bridge160ofFIG.3Amay further comprise at least one barrier or wall, such as a first wall330, between the first layer315and the second layer320. In some embodiments, the first wall330may extend from the end of the bridge160adjacent to the adapter250into the applicator240to form at least two sealed spaces or fluid pathways between the first layer315and the second layer320within the bridge160. In some examples, the bridge160may further comprise a second barrier, such as a second wall335, between the first layer315and the second layer320. In some embodiments, the second wall335also may extend from the end of the bridge160adjacent to the adapter250into the applicator240. In some example embodiments, the first wall330and the second wall335may comprise a polymeric film coupled to the first layer315and the second layer320. In some other example embodiments, the first wall330and the second wall335may comprise a weld (RF or ultrasonic), a heat seal, an adhesive bond, or a combination of any of the foregoing. In some embodiments, the first wall330and the second wall335may form distinct fluid pathways within the sealed space between the first layer315and the second layer320. InFIG.3A, for example, the first wall330and the second wall335define in part a first pathway340, a second pathway345, and a third pathway350. Each of the first pathway340, the second pathway345, and the third pathway350generally has a first end, a second end, and a longitudinal axis. In some embodiments, one or more of the fluid pathways may be fluidly coupled or configured to be fluidly coupled to the peripheral lumens310, which can provide a pressure feedback path to a sensor, such as the first sensor135. The third pathway350may be fluidly coupled to or configured to be fluidly coupled to the central lumen305.

In some example embodiments, the first pathway340, the second pathway345, and the third pathway350may be fluidly coupled to the conduit235through the adapter250. For example, the third pathway350may be fluidly coupled to the conduit235so that the third pathway350can deliver negative pressure to the tissue interface120. Each of the first pathway340and the second pathway345may be fluidly coupled to a separate one of the peripheral lumens310. In other embodiments, the first pathway340and the second pathway345both may be fluidly coupled to a common space within the adapter250, which can be fluidly coupled to one or more of the peripheral lumens310. In some example embodiments, the first pathway340, the second pathway345, and the third pathway350may terminate within the applicator240. In some embodiments, the first pathway340, the second pathway345, and the third pathway350may be in fluid communication with each other within the applicator240for delivering and sensing negative pressure associated with the tissue interface120.

The bridge160may comprise an opening or aperture, such as an aperture355, adapted to fluidly couple the sealed space of the bridge160to the tissue interface120. InFIG.3A, for example, the aperture355is disposed in the applicator240. A recessed space360within the bridge160can be adapted to be in fluid communication with the tissue interface120through the aperture355in use. In the example ofFIG.3A, the portions of first layer315and the second layer320at least partially define the recessed space360within the sealed space of the applicator240. In some example embodiments, the first wall330and the second wall335may extend only partially into the recessed space360so that the ends of the first wall330and the second wall335are exposed by the aperture355as shown in the example ofFIG.3A. In some embodiments, the first pathway340and the second pathway345may be in fluid communication with the recessed space360. The third pathway350may also be in fluid communication with the recessed space360and can be adapted to deliver negative pressure to the tissue interface120through the recessed space360. In some example embodiments (not shown), the first wall330and the second wall335may extend beyond the aperture355so that less of the first pathway340and the second pathway345are exposed to negative pressure delivered to the tissue interface120to prevent or reduce occlusions and/or blockages.

The bridge160may further comprise a means for supporting fluid paths under pressure. In some embodiments, the means of support may comprise a plurality of support features, such as a flexible projections, standoffs, nodes, cells, porous textile, porous foam, or some combination of features disposed in a fluid path. For example, the bridge160ofFIG.3Acomprises a plurality of supports365. Adjacent to the aperture355, the supports365may be adapted to come in direct contact with the tissue interface120in some examples. Support features such as the supports365can provide a cushion to prevent the sealed spaces of the bridge160from collapsing as a result of external forces. In some example embodiments, the supports365may come in contact with the second layer320, and in some other example embodiments, the top portion of the supports365may be coupled to the second layer320. In some example embodiments, the supports365may be disposed only in the applicator240, and other support features may be disposed in the bridge160between the applicator240and the conduit235.

The bridge160ofFIG.3Amay also comprise an affixation surface370surrounding the aperture355, which can be coupled to the dressing110or directly to a tissue site in some examples. In some embodiments, a top drape (not shown) may be utilized to cover the applicator240for additional protection and support over the applicator240if applied to a tissue site. In some embodiments, a top drape may also be utilized to cover any adhesive that might be exposed. In some embodiments, a top drape may be similar to the cover125. For example, a top drape may comprise or consist essentially of a polymer, such as a polyurethane film.

FIG.3Bis a schematic view of the applicator240ofFIG.3A, taken along line3B-3B, illustrating additional details that may be associated with some embodiments. For example, some embodiments of the support features may be formed by sealing a spacer layer375to the first layer315. In the example ofFIG.3B, each of the supports365comprises a standoff380in the spacer layer375. In some embodiments, the standoffs380may be formed by blisters, bubbles, cells or other raised formations that extend above or below a base385of the spacer layer375, for example. In some examples, the standoffs380may be vacuum-formed regions of the spacer layer375.

The base385may be sealed to the first layer315, and the standoffs380may extend from the first layer315toward the aperture355of the second layer320as illustrated inFIG.3B. At least some of the supports365may be configured to come in direct contact with the tissue interface120through the aperture355.

In some embodiments, the base385may be sealed to the first layer315so that the first layer315closes the standoffs380. For example, the base385may be heat-sealed to the first layer315while the standoffs380may be vacuum-formed simultaneously. In other examples, the seal may be formed by adhesion between the first layer315and the spacer layer375. Alternatively, the first layer315and the spacer layer375may be adhesively bonded to each other.

In general, the supports365are structured so that they do not completely collapse from apposition forces resulting from the application of negative pressure and/or external forces to the bridge160. In some examples, the first layer315and the spacer layer375may be formed from separate sheets or film brought into superposition and sealed, or they may be formed by folding a single sheet onto itself with a heat-sealable surface facing inward. Any one or more of the first layer315, second layer320, and the spacer layer375also may be a monolayer or multilayer structure, depending on the application or the desired structure of the support features.

In some example embodiments, the standoffs380may be substantially airtight to inhibit collapsing of the standoffs380under negative pressure, which could block the flow of fluid through the bridge160. For example, in the embodiment ofFIG.3B, the standoffs380may be substantially airtight and have an internal pressure that is an ambient pressure. In another example embodiment, the standoffs380may be inflated with air or other suitable gases, such as carbon dioxide or nitrogen. The standoffs380may be inflated to have an internal pressure greater than the atmospheric pressure to maintain their shape and resistance to collapsing under pressure and external forces. For example, the standoffs380may be inflated to a pressure up to about 25 psi above the atmospheric pressure.

In some embodiments, the first layer315, the second layer320, and the spacer layer375may each have a thickness within a range of 400 to 600 microns. For example, the first layer315, the second layer320, and the spacer layer375may be formed from thermoplastic polyurethane film having a thickness of about 500 microns. In some example embodiments, each may have a thickness of about 200 μm to about 600 μm. In some embodiments, a thickness of about 500 μm or about 250 μm may be suitable.

In some embodiments, one or more of the first layer315, the second layer320, and the spacer layer375may have a different thickness. For example, the thickness of the second layer320may be up to 50% thinner than the thickness of the spacer layer375. If the fabrication process comprises injection molding, portions of the spacer layer375defining the standoffs380may have a thickness between about 400 μm and about 500 μm. However, if the standoffs380are fabricated by drawing a film, the spacer layer375proximate a top portion of the standoffs380may have a thickness as thin as 50 μm.

After the standoffs380have been fabricated, the walls of the standoffs380may have a thickness relative to the thickness of base385. The relative thickness may be defined by a draw ratio, such as the ratio of the average height of the standoffs380to the average thickness of the spacer layer375. In some example embodiments, the standoffs380may have a generally tubular shape, which may have been formed from the spacer layer375having various thicknesses and draw ratios. In some example embodiments, the spacer layer375may have an average thickness of 500 μm and the standoffs380may have an average height in a range between about 2.0 mm and 5.0 mm. Consequently, the standoffs380may have a draw ratio ranging from about 4:1 to about 10:1 for heights of 2.0 and 5.0 mm, respectively. In another example embodiment, the draw ratio may range from about 5:1 to about 13:1 where the thickness of the spacer layer375is an average of about 400 μm. In yet other example embodiments, the draw ratio may range from about 3:1 to about 9:1 where the thickness of the spacer layer375is an average of about 600 μm. In some embodiments, the standoffs380may have an average height in a range between about 1.0 mm and 4.0 mm, depending on the thickness of the spacer layer375. The spacer layer375may have varying thicknesses and flexibilities, but is substantially non-stretchable so that the standoffs380maintain a generally constant volume if sealed to the first layer315. Additionally, the standoffs380can support a load without bursting and can recover their original shape after a load is removed.

In some example embodiments, any one or more of the first layer315, the second layer320, and the spacer layer375may be formed from a non-porous, polymeric film that may comprise any flexible material that can be manipulated to form suitable support features, including various thermoplastic materials, e.g., polyethylene homopolymer or copolymer, polypropylene homopolymer or copolymer, etc. Non-limiting examples of suitable thermoplastic polymers may include polyethylene homopolymers, such as low density polyethylene (LDPE) and high density polyethylene (HDPE), and polyethylene copolymers such as, e.g., ionomers, EVA, EMA, heterogeneous (Zeigler-Natta catalyzed) ethylene/alpha-olefin copolymers, and homogeneous (metallocene, single-cite catalyzed) ethylene/alpha-olefin copolymers. Ethylene/alpha-olefin copolymers are copolymers of ethylene with one or more comonomers selected from C3to C20alpha-olefins, such as 1-butene, 1-pentene, 1-hexene, 1-octene, methyl pentene and the like, in which the polymer molecules comprise long chains with relatively few side chain branches, including linear low density polyethylene (LLDPE), linear medium density polyethylene (LMDPE), very low density polyethylene (VLDPE), and ultra-low density polyethylene (ULDPE). Various other materials may also be suitable, such as polypropylene homopolymer or polypropylene copolymer (e.g., propylene/ethylene copolymer), polyesters, polystyrenes, polyamides, polycarbonates, etc.

In some embodiments, the polymeric film may possess sufficient tensile strength to resist stretching under apposition forces created by negative-pressure therapy. The tensile strength of a material is the ability of material to resist stretching as represented by a stress-strain curve where stress is the force per unit area, i.e., pascals (Pa), newtons per square meter (N/m2), or pounds per square inch (psi). The ultimate tensile strength (UTS) is the maximum stress the material can withstand while being stretched before failing or breaking. Many materials display a linear elastic behavior defined by a linear stress-strain relationship often extending up to a nonlinear region represented by the yield point, i.e., the yield strength of a material. For example, high density polyethylene (HDPE) has a high tensile strength and low-density polyethylene (LDPE) has a slightly lower tensile strength, which are suitable materials for the sheets of non-porous, polymeric film as set forth above. Linear low density polyethylene (LLDPE) may also be suitable for some examples because the material stretches very little as the force is increased up to the yield point of the material. Thus, the standoffs380or other support features can be configured to resist collapsing (or stretching) when subjected to an external force or pressure. For example, HDPE has a UTS of about 37 MPa and may have a yield strength that ranges from about 26-33 MPa depending on the thickness of the material, while LDPE has somewhat lower values.

In some example embodiments, one or more of the first layer315, the second layer320, and the spacer layer375may comprise or consist essentially of a thermoplastic polyurethane (TPU) film that is permeable to water vapor but impermeable to liquid. The film may be in various degrees breathable and may have MVTRs that are proportional to their thickness. For example, the MVTR may be at least 300 g/m2per twenty-four hours in some embodiments. For permeable materials, the permeability generally should be low enough to maintain a desired negative pressure for the desired negative-pressure treatment.

In some example embodiments, the thermoplastic polyurethane film may be, for example, a Platilon® thermoplastic polyurethane film available from Convestro LLC, which may have a UTS of about 60 MPa and may have a yield strength of approximately 11 MPa or greater than about 10 MPa depending on the thickness of the material. Therefore, in some example embodiments, it is desirable that the non-porous, polymeric film may have a yield strength greater than about 10 MPa, depending on the type and thickness of material. A material having a lower yield strength may be too stretchable and, therefore, more susceptible to breaking with the application of small amounts of compression and/or apposition forces.

FIG.3Cis a schematic view of another example of the applicator240, illustrating details that may be associated with some embodiments. In the example ofFIG.3C, the applicator240has more than one spacer layer375. At least some of the support features may be formed by sealing the base385of at least one of the spacer layers375to the second layer320. Some of the supports365may extend from the second layer320toward the first layer315around the recessed space360. In the example ofFIG.3C, all of the supports365around the recessed space360extend from the second layer320toward the first layer315. At least some of the supports365may also extend from the first layer315toward the aperture355in the recessed space360.

FIG.3Dis a schematic view of another example of the applicator240, illustrating additional details that may be associated with some embodiments. In the example ofFIG.3D, some of the supports365around the recessed space360extend from the second layer320toward the first layer315, and some of the supports365around the recessed space360also extend from the first layer315toward the second layer320. Some of the supports365also extend from the first layer315toward the aperture355in the recessed space360.

FIG.4Ais a schematic view of additional details that may be associated with various examples of support features in the bridge160. For example,FIG.4Aillustrates a sealed region405between the standoffs380. In some embodiments, the sealed region405may be formed by sealing portions of the spacer layer375to the first layer315or the second layer320. In the example ofFIG.4A, the sealed region405may be formed by sealing the base385to the first layer315around the standoffs380. As illustrated in the example ofFIG.4A, the standoffs380may have a circular edge proximate to the sealed region405. In other embodiments, the standoffs380may have edges with other suitable shapes, such as rectangular, triangular, or hexagonal, or some combination of shapes. Additionally or alternatively, one or more of the standoffs380may be embossed with projections or nodes, such as the nodes410illustrated in the example ofFIG.4A.

The standoffs380in adjacent rows or columns may be staggered so that the standoffs380may be nested or packed together, as illustrated in the example ofFIG.4A. In other embodiments, the standoffs380may be arranged in other patterns suitable for the particular therapy being utilized. For example, the rows and columns of the standoffs380may be arranged in line to form an aligned, rectangular pattern so that there is more spacing between the standoffs380. Increasing the spacing between the standoffs380may increase fluid flow within the fluid pathways of the bridge160, whereas a nested arrangement may restrict fluid flow within the fluid pathways. For example, the standoffs380can be aligned to increase fluid flow of negative pressure being applied to a tissue interface and facilitate the removal of fluids and exudates within the recessed space360. A nested pattern can facilitate pressure sensing within the recessed space360while impeding the inflow of fluids and exudates, which can reduce the possibility of blockage.

In some embodiments, distribution of the standoffs380may be characterized by a pitch, which can be defined by the center to center distance between each of the standoffs380. For example, a pitch of about 1 mm to about 10 mm may be suitable for some configurations. In some embodiments, the pitch may be between about 2 mm and about 3 mm. Because the sealed region405can define an end of the standoffs380, including a diameter of a circular end, and the pitch of the standoffs380, the area of the spacer layer375having the standoffs380may also be determined as a percentage. For example, if each of the standoffs380has a diameter of about 1.0 mm and the pitch is about 2.0 mm, the coverage percentage is about 22% of the area of the spacer layer375. In another example, if the diameter of each of the standoffs380is about 2.0 mm and the pitch is about 5.0 mm, the coverage percentage is about 14% of the area of the spacer layer375. In yet another example, if the diameter of each of the standoffs380is about 1.5 mm, the pitch is about 2.0 mm, and the standoffs380are more tightly arranged such that there are about 28.5 standoffs in a 10 mm2section of the spacer layer375, the coverage percentage is about 51% of the area of the spacer layer375. Depending on the diameter, pitch, and arrangement of the standoffs380, the coverage percentage may range between about 10% and about 60% of the surface area of the spacer layer375. Support features having other shapes also may have a coverage percentage in generally the same range.

The size and pitch of the standoffs380also may be varied to effect change in the fluid flows through the fluid passageways. For example, the diameter and pitch of the standoffs380can be increased to increase fluid flow of negative pressure being applied to a tissue interface and facilitate the removal of fluids and exudates within the recessed space360. The diameter, pitch, or both may be decreased to restrict fluid flow, which can reduce blockages, and facilitate pressure sensing within the recessed space360.

FIG.4Bis a schematic view of the support features ofFIG.4Ataken along section4B-4B, illustrating additional details that may be associated with some examples. In some embodiments, the standoffs380may have a hemispherical profile, as illustrated in the example ofFIG.4B. In other example embodiments, the standoffs380may be profiles that are conical, cylindrical, tubular having a flattened or hemispherical end, or geodesic. The standoffs380may be tubular in some embodiments, formed with generally parallel walls extending from the base385to a hemispherical or flat top portion of the standoffs380. Alternatively, the walls of the standoffs380may taper or expand outwardly from the base385. In some embodiments, the standoffs380that are generally hemispherical or tubular in shape may have a diameter between about 1.0 mm and about 10 mm. In some other embodiments, the standoffs380may have a diameter between about 2.0 mm and about 5.0 mm.

FIG.4Cis a schematic view of the example support features ofFIG.4Ataken along section4C-4C, illustrating additional details that may be associated with some embodiments. In the example ofFIG.4C, the nodes410can be configured to contact the tissue interface120to enhance fluid flow to a tissue site. The nodes410may be flexible or rigid. In some embodiments, the nodes410may be formed from a substantially gas impermeable material, such as silicone. In other embodiments, the nodes410may be formed from a semi-gas permeable material. The nodes410may be formed from the same material as the spacer layer375, and may be an integral part of the spacer layer375. In some embodiments, the nodes410may be solid, while in other embodiments the projections may be hollow to increase flexibility. The nodes410may form a plurality of channels and/or voids to distribute reduced pressure and allow for fluid flow among the nodes410. The nodes may be dimensioned to provide local load points evenly distributed at a tissue interface. The pattern and position of the nodes410may be uniform or non-uniform. The nodes may have different profiles, including, for example, the shape of a spike, cone, pyramid, dome, cylinder or rectangle.

FIG.5Ais a schematic view of additional details that may be associated with some embodiments of the bridge160. For example, inFIG.5Aone or more passageways505may be formed between the supports365.

FIG.5Bis a schematic view taken along section5B-5B ofFIG.5A, illustrating additional details that may be associated with some embodiments. For example, as seen inFIG.5B, at least some of the standoffs380may be fluidly coupled through the passageways505. The passageways505and the standoffs380can form a closed chamber. In some examples, a closed chamber may be formed by all of the standoffs380in a row fluidly coupled by the passageways505as shown inFIG.5AandFIG.5B. The closed chambers may be formed in alternating rows as also shown inFIG.5A. The formation of closed chambers with the standoffs380can distribute apposition forces more equally.

FIGS.6A,6B, and6Cillustrate other examples of features that may be associated with some embodiments of the bridge160. InFIG.6A, the first layer315and the spacer layer375define a nested arrangement of the supports365. The example ofFIG.6Afurther illustrates that at least some of the supports365may additionally or alternatively have different sizes. For example, some of the supports365may have a diameter in the range between about 1 mm and about 10 mm, and some of the supports365may have a diameter in the range between about 1 mm and about 3 mm. In some embodiments, a wall605may be disposed between the some of the supports365. For example, the wall605in the example ofFIG.6Ais disposed between the supports365having different sizes. The supports365having a larger diameter and pitch may increase fluid flow to facilitate the removal of fluids and exudates within the recessed space360in some embodiments. In some embodiments, the supports365having a smaller diameter and pitch may restrict fluid flow to facilitate pressure sensing within the recessed space360while impeding the inflow of fluids and exudates into the first pathway340. The arrangement and dimensions of the supports365may be tailored to manage the delivery of negative pressure to the tissue interface120and the measurement of pressure within the recessed space360.

FIG.7is a schematic diagram of the bridge160ofFIG.3Aapplied to the tissue site205with negative pressure. The tissue interface120may be in fluid communication with the recessed space360through the aperture355. The affixation surface370may be coupled to the cover125to seal and fluidly couple the recessed space360to the tissue interface120. In the example ofFIG.7, the first wall330and the second wall335partially define the first pathway340, the second pathway345, and the third pathway350between the first layer315and the second layer320.

Within the recessed space360, the standoffs380can extend from the first layer315toward the tissue interface120and may be adapted to come in direct contact with the tissue interface120if negative pressure is applied to the bridge160. Negative pressure can compress the bridge160, and the first layer315and the second layer320can collapse toward each other because of the vacuum created within the standoffs380. Although the standoffs380may change shape or flatten somewhat under negative pressure, the volume of the standoffs380remains substantially constant and can maintain fluid flow through the third pathway350. The standoffs380can also provide a cushion to help prevent the sealed spaces of the bridge160from collapsing as a result of external forces. The standoffs380disposed in the third pathway350may be sized and arranged in a pattern that may increase fluid flow of negative pressure being applied to the tissue interface120to facilitate the removal of fluids and exudates within the recessed space360. The standoffs380disposed in the first pathway340and the second pathway345may be sized and arranged in a pattern to facilitate pressure sensing within the recessed space360while impeding the inflow of fluids and exudates into the first pathway340and the second pathway345to reduce blockage conditions.

The standoffs380may have a variety of shapes, and may be sized and arranged in different patterns within the sealed space to enhance the delivery of negative pressure to the tissue interface120for a specific type of tissue site while optimizing pressure sensing and measurement of the negative pressure within the recessed space360.

FIG.8is a perspective bottom view of another example of the bridge160having a low-profile structure that may be associated with some embodiments of the therapy system100. As illustrated in the example ofFIG.8, the first wall330and the second wall335may extend lengthwise through the bridge160between the recessed space360and the adapter250.

FIG.9AandFIG.9Bare segmented perspective views of the bridge160ofFIG.8, illustrating additional details that may be associated with some examples.FIG.9Ais a bottom perspective view of an example of the applicator240, illustrating a configuration having a circular profile.FIG.9Bis a top perspective view of an example of the adapter250, which may have an elbow connector of semi-rigid material in some embodiments.

The aperture355ofFIG.9Ais generally circular and opens to the recessed space360. The supports365ofFIG.9Amay have a generally elongated and arcuate profile and may be arranged in a generally concentric pattern within the recessed space360. Some embodiments of the supports365may also comprise surface features, such as the nodes410. The supports365disposed in the center of the recessed space360may be more aligned with the third pathway350to increase fluid flow of negative pressure being applied to the tissue interface120and facilitate the removal of fluids and exudates within the recessed space360. In some embodiments, some of the supports365may be disposed around the aperture355to form a semicircular path opposite the third pathway350, including spaces805between the supports365. The semicircular alignment of the supports365may be positioned within the recessed space360to minimize contact with the flow of fluids passing through from the tissue interface120to the third pathway350if negative pressure is applied. Additionally, the spaces805may be sufficiently small for further restricting fluid flow into the first pathway340and the second pathway345, as indicated by the dashed arrows. The spaces805can facilitate pressure sensing within the recessed space360while impeding the inflow of fluids and exudates into the first pathway340and the second pathway345to reduce the possibility of blockage. In some embodiments, a portion of the perimeter of the aperture355may be welded to an outer ring of the supports365to further restrict fluid flow to the first pathway340and the second pathway345and further impede the inflow of fluids and exudates without inhibiting pressure sensing within the recessed space360.

FIG.10is an assembly view of another example of the bridge160having a low-profile structure that may be associated with some example embodiments of the therapy system100. In the example ofFIG.10, the bridge160comprises two spacer layers—a first spacer layer1005and a second spacer layer1010—disposed between the first layer315and the second layer320. In some embodiments, the first spacer layer1005and the second spacer layer1010may each be similar to spacer layer(s)375. For example, standoffs380may be formed in each of the first spacer layer1005and the second spacer layer1010. In the example ofFIG.10, the standoffs380in the first spacer layer1005are configured to extend toward the second spacer layer1010, and the standoffs380in the second spacer layer1010are configured to extend toward the first spacer layer1005. The first layer315may have a passage1015, and the first spacer layer1005may have a passage1020, through which fluids may flow to the adapter250. The first layer315and the first spacer layer1005may additionally have a passage1025and a passage1030, respectively, which may also be fluidly coupled to the adapter250. The bridge160may further comprise a fluid exit bond1035to prevent leakage of fluids flowing through the passage1015and the passage1020. The second spacer layer1010may have an aperture1040concentric with the aperture355of the second layer320. The bridge160may further comprise a fluid exit bond1045, which can prevent leakage of fluids flowing through the aperture355and the aperture1040.

In some embodiments, a bridge cover1050may provide additional protection and support over the applicator240if the bridge160is applied to a tissue site. In some embodiments, the bridge cover1050may also cover any adhesive that might be exposed from applying the bridge160to a tissue site. In some embodiments, the bridge cover1050may be similar or analogous to the cover125. For example, the bridge cover1050may be a polymer, such as a polyurethane film.

FIG.11Ais a segmented view of an assembled portion of the bridge160in the example ofFIG.10, illustrating additional details that may be associated with some embodiments. As illustrated in the example ofFIG.11A, the first layer315, second layer320, the first spacer layer1005, and the second spacer layer1010may be assembled in a stacked relationship. For example, the first layer315may be coupled to the first spacer layer1005, the second layer320may be coupled to the second spacer layer1010, and a periphery of the first spacer layer1005may be coupled to a periphery of the second spacer layer1010to form the flange325. The first spacer layer1005and the second spacer layer1010can be coupled to form a liquid barrier defining a fluid path along a longitudinal axis of the bridge160.

Some embodiments of the bridge160may additionally comprise at least one barrier or wall, such as a first barrier1105, interior to the flange325. The first barrier1105may be formed by coupling the first spacer layer1005and the second spacer layer1010. For example, the first spacer layer1005may be welded to the second spacer layer1010to form the first barrier1105. In some embodiments, the first barrier1105may extend lengthwise through the bridge160into the applicator240to form at least two fluid paths between the first spacer layer1005and the second spacer layer1010within the bridge160. In some examples, the bridge160may further comprise a second barrier, such as a second barrier1110. The second barrier1110may be formed by coupling the first spacer layer1005and the second spacer layer1010. In some embodiments, the second barrier1110also may extend lengthwise through the bridge160into the applicator240. In some example embodiments, the first barrier1105and the second barrier1110may comprise a polymeric film coupled between the first layer315and the second layer320. In some other example embodiments, the first barrier1105and the second barrier1110may comprise a weld (RF or ultrasonic), a heat seal, an adhesive bond, or a combination of any of the foregoing. The first barrier1105and the second barrier1110may be similar to the first wall330and the second wall335in some embodiments.

In some embodiments, barriers or walls interior to the flange325may form fluid pathways between the first spacer layer1005and the second spacer layer1010. For example, inFIG.11A, the first barrier1105and the second barrier1110cooperate with the flange325to form a first fluid conductor1115, a second fluid conductor1120, and a third fluid conductor1125. In some applications, the first fluid conductor1115and the second fluid conductor1120may be coupled to a sensor to measure pressure, and the third fluid conductor1125may be coupled to a negative-pressure source. In some example embodiments, the first fluid conductor1115and the second fluid conductor1120may have a height having a value in a range between about 0.25 mm and about 3 mm. In some example embodiments, the first fluid conductor1115and the second fluid conductor1120may have a width having a value in a range between about 1 mm and about 7.5 mm. Thus, the first fluid conductor1115and the second fluid conductor1120may have a cross-sectional area having a value in a range between about 0.17 mm2and 16.77 mm2. In some embodiments, the first fluid conductor1115and the second fluid conductor1120may have a cross-sectional area having a value in a range between about 0.1 mm2and 18 mm2.

In some examples, each of the first barrier1105and the second barrier1110may extend an angular distance around the proximal end of the applicator240and cooperate with blocking walls of the flange325, such as blocking walls1130, to form extensions of the first fluid conductor1115and the second fluid conductor1120. The extensions may be fluidly coupled to the recessed space360. In the example ofFIG.11A, the first fluid conductor1115and the second fluid conductor1120are fluidly coupled to the recessed space360through passages, such as a through-hole1135and a through-hole1140, respectively. In some examples, at least some of the supports may be disposed in one or both of the first fluid conductor1115and the second fluid conductor1120. For example, some of the supports may be formed by the standoffs380disposed between the flange325and the first barrier1105, and between the flange325and the second barrier1110. Additionally or alternatively, the thickness of the spacer layer1010may be increased to provide additional structural support to the first fluid conductor1115and the second fluid conductor1120. In some examples, the first fluid conductor1115and the second fluid conductor1120may comprise or be formed by tubes through or along the bridge160. Some configurations may not have the first fluid conductor1115or the second fluid conductor1120, or may have only one of the first fluid conductor1115and the second fluid conductor1120.

Each of the first barrier1105and the second barrier1110can extend at least partially around the proximal end of the applicator240that form the first fluid conductor1115and the second fluid conductor1120. For example, in some embodiments each of the first barrier1105and the second barrier1110can extend from about 45° to about 315° from the center of the third fluid conductor1125where the third fluid conductor1125is in fluid communication with the recessed space360. In some embodiments, the angular distance may be different for each of the first fluid conductor1115and the second fluid conductor1120. For example, the angular distance for each of the first fluid conductor1115and the second fluid conductor1120may be about 60° and 210°, respectively, from the third fluid conductor1125.

In some example embodiments, the through-hole1135and the through-hole1140may be separated from each other by an angular distance of at least 90°, extending around the applicator240in a direction away from the third fluid conductor1125. The spacing and disposition of the through-hole1135and the through-hole1140from each other, and from the third fluid conductor1125, can allow the first fluid conductor1115and the second fluid conductor1120to better avoid the flow of fluids passing through from the tissue interface120to the third fluid conductor1125when negative pressure is applied. Additionally, the through-hole1135and the through-hole1140may be sufficiently small for further restricting fluid flow into the first fluid conductor1115and the second fluid conductor1120. In some embodiments, the through-hole1135and the through-hole1140may have a cross-sectional area having a value in a range between about 0.17 mm2and 16.77 mm2. In some embodiments, the through-hole1135and the through-hole1140may have a cross-sectional area having a value in a range between about 0.1 mm2and 18 mm2to further restrict fluid flow to the first fluid conductor1115and the second fluid conductor1120and impede the inflow of fluids and exudates without inhibiting pressure sensing within the recessed space360.

FIG.11Bis a segmented perspective view of portion of the bridge160in the example ofFIG.10, illustrating additional details that may be associated with some embodiments.FIG.11Bfurther illustrates an example of the adapter250and the conduit235coupled to the bridge160. Each of the first fluid conductor1115and the second fluid conductor1120may be fluidly coupled directly to the conduit235in some examples. In other examples, both of the first fluid conductor1115and the second fluid conductor1120may be fluidly coupled to a single space (not shown) within the adapter250, which can be fluidly coupled to the conduit235.

In the example ofFIG.11AandFIG.11B, both the first fluid conductor1115and the second fluid conductor1120are fluidly separate from and parallel to the third fluid conductor1125. The parallel orientation can minimize the vertical profile of the bridge160, while still being resistant to collapsing under pressure that could block fluid flow through the fluid pathways.

FIG.12Ais a schematic view of an example configuration of fluid pathways in the bridge160ofFIG.10as assembled, illustrating additional details that may be associated with some embodiments.FIG.12Bis a schematic view taken along line12B-12B, andFIG.12Cis a schematic view taken along line12C-12C. The supports365may have a variety of shapes, and may be sized and arranged in different patterns within the third fluid conductor1125. For example, as illustrated in the examples ofFIG.12BandFIG.12C, some of the supports365may extend from the first layer315and some of the supports365may extend from the second layer320. In some embodiments, some of the supports365may be opposingly aligned. For example, at least some of the supports365can extend from the first layer315towards some of the supports365extending from the second layer320, and some of the supports365in opposition may contact each other. In some embodiments, the bridge160may include more than one row of the supports365. In the example ofFIG.12A, the bridge160has four rows of the supports365, and the supports365forming outside rows are offset or staggered from the supports365forming the two inside rows. Each of the first barrier1105and the second barrier1110cooperate with the flange325to form the first fluid conductor1115and the second fluid conductor1120. In some embodiments, some of the supports365may be disposed within one or both of the first fluid conductor1115and the second fluid conductor1120.

The supports365disposed in the third fluid conductor1125may have a larger diameter and pitch than the supports365in the first fluid conductor1115and the second fluid conductor1120, and may increase fluid flow to facilitate the removal of fluids and exudates within the recessed space360. The supports365in the first fluid conductor1115and the second fluid conductor1120may have a noticeably smaller diameter and pitch than the supports365in the third fluid conductor1125, and may restrict fluid flow to facilitate pressure sensing within the recessed space360while impeding the inflow of fluids and exudates into the first fluid conductor1115and the second fluid conductor1120. The arrangement and dimensions of the supports365may be tailored to manage the delivery of negative pressure to the tissue interface120and the measurement of pressure within the recessed space360.

FIG.13Ais a schematic view of another example configuration of fluid pathways in the bridge160ofFIG.10as assembled, illustrating additional details that may be associated with some embodiments.FIG.13Bis a schematic view taken along line13B-13B, andFIG.13Cis a schematic view taken along line13C-13C. The example ofFIG.13Aincludes four rows of the supports365, which are aligned both horizontally and vertically rather than being offset or staggered with each other. In some embodiments, the first fluid conductor1115and the second fluid conductor1120may be opened and supported by increasing the thickness of the first spacer layer1005.

FIG.14is an assembly view of another example of the bridge160having a low-profile structure that may be associated with some example embodiments of the therapy system100. The bridge160inFIG.14may be configured to provide instillation and negative-pressure therapy. For example, a negative-pressure pathway1405may be formed in the bridge160, and an instillation pathway may be located within the negative-pressure pathway1405. In the embodiment shown inFIG.14, the bridge160may be similar to that shown inFIG.10, but may further comprise an instillation pathway within an instillation conduit1410located within the negative-pressure pathway1405.

For example, the bridge180inFIG.14may comprise the first layer315, the first spacer layer1005, the instillation conduit1410forming the instillation pathway, the second spacer layer1010, and the second layer320. InFIG.14, the instillation conduit1410may be stacked between the first spacer layer1005and the second spacer layer1010, with the supports365of the first spacer layer1005and the supports365of the second spacer layer1010extending inward towards the instillation conduit1410. The first layer315may be adjacent to and in stacked relationship with the first spacer layer1005, opposite the instillation conduit1410. The second layer320may be adjacent to and in stacked relationship with the second spacer layer1010, opposite the instillation conduit1410. The first layer315and the second layer320may be sealed together about the perimeter, forming the enclosed negative-pressure pathway1405supported by the first spacer layer1005and the second spacer layer1010, with the instillation conduit1410located within the negative-pressure pathway1405and between the supports365of the first spacer layer1005and the second spacer layer1010.

InFIG.14, the second layer320may comprise an aperture355configured to allow fluid communication between the negative-pressure pathway1405and the ambient environment. The aperture355inFIG.14may be located in a distal end1415of the bridge160. Some embodiments may also comprise a second aperture1040located in the second spacer layer1010which may be concentric with the aperture355of the second layer320. In some embodiments, the first layer315and the second layer320may be coupled to form the enclosed space of the negative-pressure pathway1405between the first layer315and the second layer320. In some embodiments, the first layer315and the second layer320may each be formed of a film. Other embodiments may form the negative-pressure pathway1405as an open pathway using only a single spacer layer. Other embodiments may form the negative-pressure pathway1405by sealing the first spacer layer1005to the second spacer layer1010about the perimeter, for example without the need for any exterior film layers. Other embodiments may form the negative-pressure pathway1405between the first layer315and the second layer320, while having the plurality of supports located therebetween without any spacer layer. For example, longitudinal tubular supports might be located between the first layer315and the second layer320in some alternate embodiments, along with the instillation conduit1410.

In some embodiments, the instillation pathway and the negative pressure pathway may be located within a single bridge160, as shown inFIG.14. In some embodiments, the bridge160may be configured with a low profile. For example, the bridge160may have a height of approximately 5 millimeters. Some embodiments may have a height of less than approximately 5 millimeters. Some embodiments of the bridge160may have a length from approximately 200 millimeters to 500 millimeters.

FIG.15Ais a plan view of the bridge160ofFIG.14, illustrating additional details that may be associated with some embodiments. As shown inFIG.15A, the negative-pressure pathway1405is supported as an open pathway by the plurality of supports365. In some embodiments, the plurality of supports365may be configured to support the negative-pressure pathway1405substantially along its entire length and/or width. For example, the supports365may be co-extensive with the negative-pressure pathway1405. In some embodiments, the plurality of supports365may be arranged in rows, and the rows may be aligned and may extend longitudinally. For example, the rows may extend the length of the bridge160, with longitudinally extending spaces of the negative-pressure pathway1405separating the rows. The row configuration of supports365may allow fluid flow longitudinally from one end of the negative-pressure pathway1405to the other, for example when the bridge160is under compression. For example, in the row configuration of supports365, the longitudinally extending spaces may provide unobstructed flow channels of the negative-pressure pathway1405between the rows of supports365.

In some embodiments, the bridge160may comprise a port1505configured to fluidly couple the negative-pressure pathway1405to a negative pressure source and fluidly couple the instillation conduit1410to an instillation source. For example, the port1505may be located in a proximal end1510of the bridge160, and the negative-pressure pathway1405and the instillation conduit1410comprising the instillation pathway may each extend from the port1505to approximately the aperture in the distal end1415. Some embodiments of the port1505may be similar to the adapter250.

Some embodiments of the bridge160may comprise a pressure-sensing pathway1515that extends parallel to the negative-pressure pathway1405. In some embodiments, the pressure-sensing pathway1515may be similar to the first pathway340or the second pathway345inFIG.3Aor the first fluid conductor1115or second fluid conductor1120inFIG.11A. The pressure-sensing pathway1515may be pneumatically isolated from the negative-pressure pathway1405and the instillation pathway1410except through the aperture in the distal end1415of the bridge160. For example, the port1505may further be configured to fluidly couple the pressure-sensing pathway1515to a pressure sensor, and the pressure-sensing pathway1515may extend from the port1505to approximately the aperture. In some embodiments, the pressure-sensing pathway1515may be formed by a barrier1105between the inner surface of the first layer315and the inner surface of the second layer320of the negative-pressure pathway1405, for example forming the pressure-sensing pathway1515within the enclosed space of the negative-pressure pathway1405. In some embodiments, a plurality of pressure-pathway supports1520may be located in the pressure sensing pathway. InFIG.15A, for example, the plurality of pressure-pathway supports1520in the pressure-sensing pathway1515may be smaller than the plurality of supports365in the negative-pressure pathway1405, and may be configured to support the pressure-sensing pathway1515against collapse.

FIG.15Bis a schematic longitudinal cross-section slice view of the bridge160ofFIG.15A, illustrating additional details that may be associated with some embodiments.FIG.15Billustrates the distal end1415of the bridge160and shows the instillation conduit1410located within the negative-pressure pathway1405and extending longitudinally in the negative-pressure pathway1405. For example, the instillation conduit1410may extend substantially the length of the negative-pressure pathway1405. The instillation conduit1405may extend from the port to the recessed space360or aperture355in some embodiments. The instillation conduit1410may form an instillation pathway1525, for example with the instillation pathway1525inFIG.15Blocated within the instillation conduit1410. The instillation pathway1525may be configured to allow flow of instillation fluid during the instillation process. As shown inFIG.15B, the plurality of supports365of the bridge160may comprise a first plurality of supports1425and a second plurality of supports1430. The instillation pathway1525may be located between the first plurality of supports1425and the second plurality of supports1430. In some embodiments, the first plurality of support1425may be opposingly aligned with the second plurality of supports1430, for example to support the negative-pressure pathway1405. The instillation pathway1525may be located between at least a portion of the first plurality of supports1425and the second plurality of supports1430. In some embodiments, the first spacer layer1005may comprise the first plurality of supports1425, and the second spacer layer1010may comprise the second plurality of supports1430. For example, the first plurality of supports1425may extend inward from an inner surface of the first spacer layer1005, and the second plurality of supports1430may extend inward from an inner surface of the second spacer layer1010. The first plurality of supports1425and the second plurality of supports1430may each be aligned into longitudinally extending rows. For example, the first plurality of supports1425may be aligned into rows that match the rows of the second plurality of supports1430, so that the first plurality of supports1425may be opposingly aligned and stacked with the second plurality of supports1430.

In some embodiments, the instillation pathway1525may be configured to fluidly communicate with the negative-pressure pathway1405through the recessed space360in the negative-pressure pathway1405. In some embodiments, the recessed space360may be configured to fluidly communicate with the ambient environment through the aperture355in the second layer. For example, the instillation pathway1525may be configured to interact with the negative-pressure pathway1405so that at least a portion of the instillation pathway1525collapses upon application of negative pressure to the negative-pressure pathway1405. In some embodiments, the negative-pressure pathway1405and the instillation pathway1525may each comprise enclosed conduits configured for fluid transfer from one end to another end of the bridge160. For example, the negative-pressure pathway1405and the instillation pathway1525may each comprise a separate enclosed space for fluid flow from the proximal end1510to the distal end1415of the bridge160. In some embodiments, the supports365may be located within the enclosed space of the negative-pressure pathway1405.

In some embodiments, the negative-pressure pathway1405and the instillation pathway1525may be pneumatically isolated from each other and/or the ambient environment except through the recessed space360and/or the aperture355in the distal end1415of the bridge160. For example, the instillation pathway1525may be pneumatically isolated from the negative-pressure pathway1405except through the recessed space360in the distal end of the negative-pressure pathway1405. In some embodiments, the instillation pathway1525may interact with the negative-pressure pathway1405pneumatically through the recessed space360, thereby providing fluid communication. In the example ofFIG.15B, the distal end of the instillation pathway1525may be in fluid communication with the negative-pressure pathway1405through the recessed space360, allowing any negative pressure that is applied to the negative-pressure pathway1405to also operate on the instillation pathway1525in a way that may cause at least a portion of the instillation pathway1525to collapse. For example, the recessed space360in the distal end of the negative-pressure pathway1405may be in fluid communication with the open distal end of the instillation pathway1525. In some embodiments, the recessed space360may comprise the aperture355. For example, the recessed space360inFIG.15Bmay comprise the aperture355in conjunction with the second aperture1040. In some embodiments, the aperture355may be configured to allow fluid communication between the recessed space360and the ambient environment. In some embodiments, the negative-pressure pathway1405and/or the instillation pathway1525may be in fluid communication with the ambient environment through the aperture355. For example, the negative-pressure pathway1405and the instillation pathway1525may be pneumatically isolated from the ambient environment except through the aperture355and/or the second aperture1040.

In some embodiments, the instillation pathway1525and the negative-pressure pathway1405may interact through contact of the supports365of the negative-pressure pathway1405with the instillation pathway1525. For example, as negative-pressure is applied to the negative-pressure pathway1405, the supports365may clamp down on the instillation pathway1525, which may collapse at least a portion of the instillation pathway1525. In some embodiments, at least a portion of the instillation pathway1525may collapse across the width of the instillation pathway1525upon application of negative pressure, for example due to clamping of supports and/or suction within the instillation pathway from negative-pressure.

In some embodiments, collapse of the instillation pathway1525may be sufficient to close the instillation pathway1525, substantially preventing fluid flow through the instillation pathway1525. For example, collapse of the instillation pathway1525may operate to prevent siphoning of instillation fluid when negative pressure is applied to the negative-pressure pathway1405. In some embodiments, the instillation pathway1525may comprise a collapsible conduit, for example configured to interact with the negative-pressure pathway1405so that the collapsible instillation conduit1410collapses along its entire length upon application of negative pressure to the negative-pressure pathway1405. For example, the instillation pathway1525inFIG.15Bmay comprise no internal support, such that there may be no instillation supports within the instillation pathway1525. Instead, the instillation pathway1525may be configured to collapse, for example when there is no fluid pressure within the instillation pathway1525and/or when the instillation pathway1525experiences negative pressure. By way of example, the collapsible instillation conduit1410may comprise a thin polyurethane film tube, which may have a material thickness of the polyurethane material from approximately 30 to 80 micron.

In some embodiments, each of the supports365of the first spacer layer1005may comprise a hollow standoff380, and the first layer315may be sealed to the first spacer layer1005to maintain internal pressure within the plurality of hollow standoffs380. In some embodiments, each of the plurality of supports365may comprise a standoff380and a base, with the standoff having a closed surface extending away from the base. Similarly, each of the second plurality of supports1430of the second spacer layer1010may comprise a hollow standoff380, and the second layer320may be sealed to the second spacer layer1010to maintain internal pressure within the standoffs380of the second plurality of supports1430. In some embodiments, the first layer315and/or the second layer320may comprise a polyurethane film from approximately 80 to 120 micron in thickness. In some embodiments, the first spacer layer1005and/or the second spacer layer1010may be thermoformed structures with integral open pathway features, such as supports365. In some embodiments, the thermoformed structures may comprise thermoplastic polyurethane, for example thermoplastic polyurethane film from approximately 200 to 500 microns in thickness. The supports365may comprise a variety of shapes, for example substantially circular, hexagonal, oval, triangular, and/or square. In some embodiments, the standoffs380may each comprise a blister, a bubble, or a cell. In some embodiments, all of the standoffs380may be similarly sized and/or shaped. In some embodiments, the supports365may comprise a diameter from approximately two to four millimeters and/or a height from approximately two to five millimeters.

In some embodiments, the first plurality of supports1425may be aligned with and in stacked relationship with the second plurality of supports1430, and the instillation pathway1525may be located between at least some of the stacked first plurality of supports1425and second plurality of supports1430. In some embodiments, the first plurality of supports1425and the second plurality of supports1430may work together to jointly support the negative-pressure pathway1405. For example, the first plurality of supports1425may be stacked and opposingly aligned with the second plurality of supports1430. In some embodiments, the first spacer layer1005and second spacer layer1010may be stacked, with the instillation pathway1525sandwiched therebetween. For example, the first plurality of supports1425of the first spacer layer1005may be stacked with the second plurality of supports1430of the second spacer layer1010, with supporting faces substantially parallel and/or contacting. In some embodiments, the first plurality of supports1425and the second plurality of supports1430may jointly support the negative-pressure pathway to maintain an open pathway with a height substantially equal to the height of one of the first plurality of supports1425and one of the second plurality of supports1430taken together (e.g. stacked to provide a cumulative height). In some embodiments, the instillation pathway1525may be located between and in stacked relationship with at least some of the first plurality of supports1425and at least some of the second plurality of supports1430, for at least a portion of the negative-pressure pathway1405.

FIG.15Cis a schematic horizontal cross-section view of the bridge160ofFIG.15A, illustrating additional details that may be associated with some embodiments. Some embodiments of the negative-pressure pathway1405may be similar to the third pathway350ofFIG.3Aand/or the third fluid conductor1125ofFIG.11A. In some embodiments, the negative-pressure pathway1405may be configured to maintain an open pathway despite application of negative-pressure and/or external compression loading. In some embodiments, the plurality of supports365are configured to maintain the negative-pressure pathway1405as an open pathway, for example allowing negative pressure to be applied to a tissue site through the negative-pressure pathway even when the negative-pressure pathway1405experiences compressive loads. For example, the negative-pressure pathway1405may be maintained in an open position, without collapsing in a way that may close off the negative-pressure pathway1405, even if the patient is lying atop the bridge160. In some embodiments, the instillation pathway1525may be configured with respect to the negative-pressure pathway1405so that the supports365of the negative-pressure pathway1405also ensure that the instillation pathway1525remains at least partially open for instillation. For example, the instillation pathway1525within the instillation conduit1410may be located with respect to the supports365of the negative-pressure pathway1405so that at least a portion of the instillation pathway1525may be maintained as open between the supports365during instillation, allowing instillation fluid flow through the instillation pathway1525even when the patient is lying atop the bridge160. In some embodiments, the plurality of supports365may be configured to support the negative-pressure pathway1405substantially along its entire length and/or width. For example, the supports365may be co-extensive with the negative-pressure pathway1405. In some embodiments, the supports365may be sealed to maintain an internal pressure. For example, the supports365may be maintained at a pressure at or above atmospheric pressure, which may aid in resisting compression or collapse.

As shown in inFIG.15C, the instillation pathway1525may span a portion, but not all, of the width of the negative-pressure pathway1405. In some embodiments, at least a portion of the first plurality of supports1425may be located on the opposite side of the instillation pathway1410from at least a portion of the second plurality of supports1430. The remainder of the negative-pressure pathway1405may comprise another portion of the first plurality of supports1425stacked directly adjacent to another portion of the second plurality of supports1430(e.g. without the instillation pathway1410therebetween). For example, the instillation pathway1525may span the widths of two or more supports365. In some embodiments, at least a portion of the instillation pathway1525may span one or more spaces between two or more rows of supports365. In some embodiments, the instillation pathway1525may span substantially the entire width of the negative-pressure pathway1405. In the example ofFIG.15C, the instillation pathway1525may be located within an expandable conduit. For example, the conduit may typically be substantially flat when no instillation fluid is located within it, but may expand out to open when instillation fluid flow is present.

FIG.15Cillustrates instillation through the instillation pathway1525when there is no compression applied to the bridge160. The instillation pathway1525inFIG.15Cmay expand and/or open during instillation fluid flow, for example pushing the first plurality of supports1425away from the second plurality of supports1430. Instillation fluid may then be pumped through the instillation pathway1525.

FIG.15Dis a schematic cross-section view of the bridge160ofFIG.15A, illustrating additional details that may be associated with some embodiments. In the example ofFIG.15D, the instillation pathway1525may be configured to expand and/or open when the bridge160is under compression, to substantially fill spaces between the rows of supports365during instillation. This configuration may allow instillation even when the bridge160is under compression, ensuring that an open instillation pathway1525may be maintained despite compression. For example, the tube-like conduit of the instillation pathway1525may interact with the plurality of supports365so that the instillation conduit1410expands and/or opens into the spaces between the rows of supports365, thereby allowing longitudinal fluid flow through at least a portion of the instillation pathway1525even when the bridge160is under sufficient compression so that the first plurality of supports1425and the second plurality of supports1430are in close proximity (e.g. substantially contacting). In some embodiments, the portions of the instillation pathway1525between the first plurality of supports1425and the second plurality of supports1430might be compressed flat between opposing supports365during compression, but the portions of the instillation pathway1525between the rows of supports365may expand and/or open to substantially fill longitudinally extending spaces between the rows of supports365during instillation.

FIG.15Eis a schematic cross-section view of the bridge160ofFIG.15A, illustrating additional details that may be associated with some embodiments. In the example ofFIG.15E, instillation is not occurring. Rather, negative pressure is being applied to the negative-pressure pathway1405. The instillation pathway1525may collapse to be substantially flat and/or closed during negative-pressure therapy. For example, the portions of the instillation pathway1525clamped between opposingly aligned supports365may be substantially flat, and the portions of the instillation pathway1525spanning the spaces between the opposingly aligned supports365may also be drawn substantially flat due to negative pressure. For example, communication of negative pressure into the instillation pathway1525from the negative-pressure pathway1405during negative-pressure therapy may flatten the instillation pathway1525. This configuration may maximize flow capability through the negative-pressure pathway1405during negative-pressure therapy by minimizing the size of the instillation pathway1525at such time. During negative-pressure therapy, fluid may be removed through the longitudinally extending rows between the plurality of supports365, with only minor flat-profile disruption in spaces spanned by the flattened instillation pathway1525. In some embodiments, the flat configuration of the instillation pathway1525during negative-pressure therapy may result in substantially no blockage of flow through the negative-pressure pathway1405during fluid removal. This may be true whether or not external compression is applied to the bridge160. During negative-pressure therapy in some embodiments, the first plurality of supports1425may be drawn towards the second plurality of supports1430, so that the supporting faces substantially contact. For example, some supporting faces of supports365may directly contact opposing support faces, while some supports365may only be separated from opposingly aligned supports365by a substantially flat instillation pathway1525.

FIG.16is a partial assembly schematic view of another, similar bridge160, illustrating additional details that may be associated with some embodiments. In some embodiments, the instillation pathway1525may have a shape matching the supports365spanning at least a portion of the width of the negative-pressure pathway1405. In some embodiments, the instillation pathway1525may have a corrugated shape, for example flat where interacting with a row of supports365, and non-flat (e.g. shaped or capable of expanding and/or opening to allow fluid flow) in spaces between rows of supports365. Shaped instillation pathway embodiments may still be configured to be collapsible, however, in order to prevent siphoning of fluid during negative-pressure therapy. In some embodiments, the instillation pathway1525may comprise a plurality of collapsible longitudinal conduits located between the supports365in the enclosed space of the negative-pressure pathway1405.

In some embodiments, the instillation pathway may be located in a separate bridge from the negative-pressure pathway. In such embodiments, the instillation pathway may still be configured to interact with the negative-pressure pathway, for example by fluid communication therebetween, so that at least a portion of the instillation pathway collapses upon application of negative pressure to the separate negative-pressure pathway.

FIG.17is an assembly view of an example of the dressing interface260for instillation that may be associated with some example embodiments of the therapy system100. In some embodiments, the dressing interface260may comprise an instillation bridge1705. The instillation bridge1705may be similar to the bridge160ofFIG.10in construction, but may comprise a gap1710in the open pathway of the instillation bridge1705with no supports. In some embodiments, the instillation bridge1705may be configured to provide instillation but not negative pressure. In some embodiments, the instillation bridge1705may be configured to allow application of instillation fluid during instillation, but to minimize or prevent siphoning of instillation fluid during negative-pressure therapy (for example administered through a separate negative-pressure bridge).

In some embodiments, the instillation bridge1705may comprise a first instillation layer1715, a first instillation spacer layer1720, a second instillation spacer layer1725, and a second instillation layer1730. InFIG.17, the first instillation spacer layer1720and the second instillation spacer layer1725may be stacked adjacent one another with instillation supports1735facing inward and/or contacting. For example, the instillation pathway1525may comprise a first instillation spacer layer1720and a second instillation spacer layer1725, each having instillation supports1735projecting inward into an enclosed space of the instillation pathway1525. The first instillation layer1715may be adjacent to and in stacked relationship with the first instillation spacer layer1720, opposite the second instillation support layer1725. The second instillation layer1730may be adjacent to and in stacked relationship with the second instillation spacer layer1725, opposite the first instillation spacer layer1720. The first instillation layer1715and the second instillation layer1730may be sealed together about the perimeter, forming the enclosed instillation pathway1525supported by the first instillation spacer layer1720and the second instillation spacer layer1725.

InFIG.17, the second instillation layer1730may comprise an instillation aperture1740configured to allow fluid communication between the instillation pathway1525and the ambient environment. The instillation aperture1740inFIG.17may be located in a distal end1745of the instillation bridge1705. Some embodiments may also comprise a second instillation aperture1750located in the second instillation spacer layer1725which may be concentric with the instillation aperture1740. In some embodiments, the first instillation layer1715and the second instillation layer1730may each be formed of a film. Other embodiments may form the instillation pathway1525as an open pathway using only a single spacer layer. Other embodiments may form the instillation pathway1525by sealing the first instillation spacer layer1720to the second instillation spacer layer1725about the perimeter, for example without the need for any exterior film layers. Other embodiments may form the instillation pathway1525between the first instillation layer1715and the second instillation layer1730, while having the plurality of instillation supports located therebetween without any instillation spacer layers. For example, longitudinal tubular supports might be located between the first instillation layer1715and the second instillation layer1730in some alternate embodiments.

In some embodiments, the first instillation layer1715and/or the second instillation layer1730may comprise a polyurethane film from approximately 80 to 120 micron in thickness. In some embodiments, the first instillation spacer layer1720and/or the second instillation spacer layer1725may be thermoformed structures with integral open pathway features, such as instillation supports1735. In some embodiments, the thermoformed structures may comprise thermoplastic polyurethane, for example thermoplastic polyurethane film from approximately 200 to 500 microns in thickness. Some embodiments of the dressing interface260may be configured with a low profile. For example, the dressing interface260may be configured as a low-profile instillation bridge1705, which may have a height of approximately 5 millimeters or less.

FIG.18Ais a plan view of the instillation bridge1705ofFIG.17, illustrating additional details that may be associated with some embodiments. In some embodiments, the instillation pathway1525may extend from an instillation port1805to the instillation aperture in the distal end1745of the instillation bridge1705. In some embodiments, the plurality of instillation supports1735may be arranged in rows, and the rows may be aligned. For example, the rows may be aligned to extend longitudinally for approximately the entire length of the instillation bridge1705. In the example shown inFIG.18A, longitudinally extending spaces may separate the rows of instillation supports1735, providing unobstructed channels for fluid flow during instillation. In some embodiments, the longitudinally extending spaces may extend substantially from the instillation port1805to the instillation aperture1740.

As shown inFIG.18A, the instillation pathway1525may have a portion without any supports, forming a gap1710in the supports of the open pathway. For example, the gap1710may span the width of the instillation pathway1525and provide no support across such width. In some embodiments, except for the gap1710, the plurality of instillation supports1735may be co-extensive with the instillation pathway1525. For example, the instillation supports1735may span substantially the width and length of the instillation pathway1525, except for the gap1710(which may be unsupported). Except for the presence of the gap1710, some embodiments of the instillation bridge1705may be similar in material and/or construction to the negative-pressure bridge160ofFIG.10. The gap1710in the example ofFIG.18Amay be located in proximity to the proximal end1810and/or the instillation port1805. In other embodiments, the gap1710may be located at different positions along the length of the instillation pathway1525, for example in proximity to the distal end1745and/or the instillation aperture. In some embodiments, the instillation pathway1525may have two or more gaps1710, for example positioned at various locations along the length of the instillation pathway1525.

FIG.18Bis a schematic longitudinal cross-section slice view of a portion of the bridge160ofFIG.18A, illustrating additional details that may be associated with some embodiments. As shown inFIG.18B, the first instillation spacer layer1720and the second instillation spacer layer1725may each have a portion without instillation supports, which may jointly form the gap1710. The instillation pathway1525may be pneumatically isolated from the ambient environment except through the instillation aperture1740in the distal end1745of the instillation bridge1705. The plurality of instillation supports1735within the instillation pathway1525may be configured to support the instillation pathway1525, except for the gap1710between the plurality of instillation supports1735. The gap1710may be configured to allow collapse across the width of the instillation pathway1525upon application of negative pressure. For example, the gap1710may not have any instillation supports1735. Collapse of the gap1710in the instillation pathway1525may be sufficient to close the instillation pathway1525, substantially preventing fluid flow through the instillation pathway1525and/or substantially preventing siphoning of instillation fluid upon application of negative pressure. The instillation supports1735may be similar to the plurality of supports365inFIG.10, in some embodiments.

FIG.18Cis a schematic view of a portion of the instillation bridge1705ofFIG.18A, illustrating additional details that may be associated with some embodiments. AsFIG.18Cillustrates, in some embodiments the instillation bridge1705may comprise a first instillation layer1715and a second instillation layer1730, which may be coupled to form an enclosed space of the instillation pathway1525between the first instillation layer1715and the second instillation layer1730. The plurality of instillation supports1735may be located between the first instillation layer1715and the second instillation layer1730. In some embodiments, the plurality of instillation supports1735may comprise a first plurality of instillation supports1815and a second plurality of instillation supports1820. For example, the first plurality of instillation supports1815may extend inward from an inner surface of the first instillation spacer layer1720; and the second plurality of instillation supports1820may extend inward from an inner surface of the second instillation spacer layer1725. In some embodiments, the first plurality of instillation supports1815and the second plurality of instillation supports1820may be aligned and stacked, for example jointly supporting the instillation pathway1525. In some embodiments, the first plurality of instillation supports1815and the second plurality of instillation supports1820may each be aligned into longitudinally extending rows. For example, the first plurality of instillation supports1815may be aligned into rows that match the rows of the second plurality of instillation supports1820, so that the first plurality of instillation supports1815may be opposingly aligned and stacked with the second plurality of instillation supports1820. In some embodiments, the first plurality of instillation supports1815and the second plurality of instillation supports1820may jointly support the instillation pathway1525to maintain an open pathway with a height substantially equal to the height of one of the first plurality of instillation supports1815and one of the second plurality of instillation supports1820taken together (e.g. stacked to provide a cumulative height).

In some embodiments, the first instillation layer1715may be sealed to the first instillation spacer layer1720, and the second instillation layer1730may be sealed to the second instillation spacer layer1725. For example, each of the first plurality of instillation supports1815of the first instillation spacer layer1720may comprise a hollow standoff380, and the first instillation layer1715may be sealed to the first instillation spacer layer1720to maintain internal pressure within the plurality of hollow standoffs380of the first instillation spacer layer1720. Each of the second plurality of instillation supports1820of the second instillation spacer layer1725may comprise a hollow standoff380, and the second instillation layer1730may be sealed to the second instillation spacer layer1725to maintain internal pressure within the plurality of hollow standoffs380of the second instillation spacer layer1725. In some embodiments, each of the plurality of instillation supports1735may comprise a standoff380and a base, with the standoff380having a closed surface extending away from the base. An opening in the base may be sealed by a film attached to the base, for example maintaining internal pressure within the hollow standoffs380. The instillation supports1735may comprise a variety of shapes, for example substantially circular, hexagonal, oval, triangular, and/or square. In some embodiments, the standoffs380of the first instillation spacer layer1720and/or the second instillation spacer layer1725may each comprise a blister, a bubble, or a cell. In some embodiments, all of the standoffs380may be similarly sized and/or shaped. In some embodiments, the instillation supports1735may comprise a diameter from approximately two to four millimeters and/or a height from approximately two to five millimeters.

FIG.18Cillustrates the instillation pathway1525ofFIG.18Aduring instillation and/or when there is no negative pressure applied, and the gap1710is in an open configuration. For example, the fluid pressure during instillation may ensure that the gap1710does not collapse. The gap1710without supports may operate as shown inFIG.18Cto allow fluid flow through an open pathway during instillation. In some embodiments, the instillation pathway1525may be configured to allow instillation even when under compression. For example, the instillation supports1735may support the instillation pathway1525to maintain an open pathway for instillation even under compression.

FIG.18Dis a schematic view of a portion of the instillation bridge1705ofFIG.18A, illustrating additional details that may be associated with some embodiments.FIG.18Dillustrates the instillation bridge1710when experiencing negative-pressure in the instillation pathway1525. AsFIG.18Dillustrates, in some embodiments when negative pressure is applied to the instillation pathway1525, the negative pressure may cause the gap1710to collapse. For example, the negative pressure within the instillation pathway1525may draw the first instillation layer1715and the second instillation layer1730(and/or the first instillation spacer layer1720and the second instillation spacer layer1725) together at the gap1710, closing off the instillation pathway1525to restrict or prevent fluid flow therethrough. The gap1710may flex inward to collapse across the width of the instillation pathway1525upon application of negative pressure, to close the instillation pathway1525. For example, the gap1710inFIG.18Dis shown in a closed configuration. Collapse of the gap1710in the instillation pathway1525may be sufficient to close the instillation pathway1525, substantially preventing fluid flow through the instillation pathway1525and/or substantially preventing siphoning of instillation fluid upon application of negative pressure.

Upon removal of the negative pressure, the instillation pathway1525may re-open in some embodiments, for example with the first instillation layer1715and the second instillation layer1730(and/or the first instillation spacer layer1720and the second instillation spacer layer1725) at the gap1710flexing or springing back to the open position shown inFIG.18C. For example, the gap may re-open to have a height substantially similar to that of the remainder of the instillation pathway1525. In some embodiments, providing or pumping instillation fluid to the instillation pathway1525may re-open the gap1710. In some embodiments, the gap1710may be located with instillation supports1735on both sides of the gap1710, for example proximally and distally. In some embodiments, the gap1710may be sized large enough to allow sufficient flexing to close, while also being sized small enough so that the instillation supports1735may prevent collapse of the gap1710due to external compression loading (for example if a patient lies atop the instillation bridge1705). For example, the instillation pathway1525of the installation bridge1705may be configured to maintain an open fluid pathway when fluid is applied therethrough. The instillation pathway1525may also be configured to interact with the negative-pressure pathway of a separate negative-pressure bridge through the instillation aperture1740so that, upon application of negative pressure, at least a portion (e.g. the gap1710) of the instillation pathway1525collapses. For example, negative pressure applied to the instillation pathway1525of the instillation bridge1705may cause collapse and closing of the gap1710. Negative pressure may be applied to the instillation pathway1525through the instillation aperture in some embodiments.

FIG.19is a schematic diagram of another example embodiment of the therapy system100configured to apply negative pressure and treatment solution to a tissue site205. For example, the therapy system100shown inFIG.19may include two separate low-profile bridges, such as the bridge160for application of negative pressure to the tissue site205, and the instillation bridge1705for application of instillation fluid to the tissue site205. For example, the dressing interface260of the system may comprise the instillation bridge1705. Some embodiments of the system may comprise a negative-pressure delivery system, such as negative-pressure bridge160, that comprises a negative-pressure pathway that is pneumatically isolated from the ambient environment and from the instillation bridge1705except through an aperture355in a distal end of the negative-pressure pathway; and the instillation bridge1705ofFIG.17.

In some embodiments, the negative-pressure pathway may comprise supports365. For example, the supports365may be co-extensive with the negative-pressure pathway. In some embodiments, the instillation pathway of the instillation bridge1705may be configured to interact with the negative-pressure pathway so that, upon application of negative pressure to the negative-pressure pathway, the gap1710collapses to close the instillation pathway of instillation bridge1705. For example, the aperture355of the negative-pressure pathway and the instillation aperture1740of the instillation pathway may both be in fluid communication with the tissue site205, and negative pressure applied to the negative-pressure pathway may be in fluid communication with the instillation pathway through the tissue site205. Collapse of the gap1710of the instillation pathway, for example due to application of negative pressure, may be sufficient to close the instillation pathway and/or prevent siphoning of instillation fluid when negative pressure is applied to the negative-pressure pathway in some embodiments, substantially preventing fluid flow through the instillation pathway.

In some embodiments, the instillation pathway of the instillation bridge1705may be in fluid communication with a solution source145, while the negative-pressure pathway of the negative-pressure bridge160may be in fluid communication with a negative-pressure source105. For example, the instillation port1805of the instillation pathway may be in fluid communication with the solution source145, and the port1505of the negative-pressure pathway may be in fluid communication with the negative-pressure source105. In some embodiments, the instillation pathway may be located in a separate bridge (e.g. instillation bridge1705) from the negative-pressure pathway (e.g. located in negative-pressure bridge160), as shown inFIG.19. In some embodiments, the instillation pathway may be configured to maintain an open fluid pathway when fluid is applied therethrough and/or when there is no negative pressure (for example, despite external compression loading). In some embodiments, the negative-pressure pathway may be configured to maintain an open pathway despite application of negative-pressure and/or external compression loading. Each of the instillation bridge1705and the negative-pressure pathway bridge160may be configured with a low profile, in some embodiments.

The systems, apparatuses, and methods described herein may provide significant advantages. For example, some embodiments may maintain separate instillation and negative-pressure treatment pathways. Some embodiments may have a low-profile and/or be conformable, for improved comfort if positioned under a patient for example. Some embodiments may be configured to prevent occlusion, maintaining an open pathway for negative-pressure treatment and/or instillation fluid delivery so that the negative pressure and/or instillation fluid may be provided even when the device is under compressive load (for example, if the patient is lying atop the device). Some embodiments may improve access to certain wound sites. Some embodiments may be configured to minimize unintended siphoning of instillation fluid during negative-pressure treatment. The configuration of some embodiments may reduce contamination of instillation fluid, for example by preventing exudate from flowing into the instillation system. Some embodiments may allow wound pressure monitoring, which may for example reduce the risk of pressure drop between the pad and the wound. Some embodiments may employ a single bridge which contains both the negative-pressure pathway and the instillation pathway, which may simplify instillation and use.

While shown in a few illustrative embodiments, a person having ordinary skill in the art will recognize that the systems, apparatuses, and methods described herein are susceptible to various changes and modifications that fall within the scope of the appended claims. Moreover, descriptions of various alternatives using terms such as “or” do not require mutual exclusivity unless clearly required by the context, and the indefinite articles “a” or “an” do not limit the subject to a single instance unless clearly required by the context. Components may be also be combined or eliminated in various configurations for purposes of sale, manufacture, assembly, or use. For example, in some configurations the dressing110, the container115, or both may be eliminated or separated from other components for manufacture or sale. In other example configurations, the bridge160may also be manufactured, configured, assembled, or sold independently of other components.